Method and apparatus for controlled or programmable cutting of multiple nested tubulars

Abstract

A methodology and apparatus for cutting shape(s) or profile(s) through well tubular(s), or for completely circumferentially severing through multiple tubulars, including all tubing, pipe, casing, liners, cement, other material encountered in tubular annuli. This rigless apparatus utilizes a computer-controlled, downhole robotic three-axis rotary mill to effectively generate a shape(s) or profile(s) through, or to completely sever in a 360 degree horizontal plane wells with multiple, nested strings of tubulars whether the tubulars are concentrically aligned or eccentrically aligned. This is useful for well abandonment and decommissioning where complete severance is necessitated and explosives are prohibited, or in situations requiring a precise window or other shape to be cut through a single tubular or plurality of tubulars.

Claims

1. A method of programmably severing a plurality of nested tubulars, each tubular having a tubular bore, the nested tubulars being disposed in a well bore and wherein there is an outer tubular and an at least one inner tubular inside the bore of the outer tubular, the method comprising the steps of: (a) providing a cutting tool, the cutting tool including: (i) a tool body configured to be lowered into the tubular bore of the innermost nested tubular, the tool body having a longitudinal Z-axis, a W-axis of rotation rotating about the Z-axis, and an anchoring system attached to the tool body, the anchoring system having engaged and non-engaged conditions, wherein during the engaged condition the tool body is anchored relative to the innermost tubular, and during the non-engaged position the tool body is not anchored relative to the innermost tubular; (ii) the tool body including a cutting head movably connected to the tool body in both the Z and W axes; (iii) the cutting head being coupled to a first motor drive, wherein the first motor drive causing the cutting head to be moved in the W-axis of rotation relative to the tool body; (iv) the cutting head being coupled to a second motor drive, wherein the second motor drive causing the cutting head to be moved in the Z-axis relative to the tool body; (v) the cutting head including: a spindle housing pivotally connected to the cutting head at a pivot axis allowing pivoting in a Y-axis, the spindle housing having: (1) an elongated cutting member with distal and proximal ends, and the elongated cutting member being rotationally connected to the spindle housing, the elongated cutting member having a longitudinal axis, the longitudinal axis being perpendicular to the pivot axis of the spindle housing, (2) a third motor drive operably connected to the elongated cutting member causing the elongated cutting member to rotate about the elongated cutting member's longitudinal axis and relative to the spindle housing; (3) an arcuate actuator operatively connected to the spindle housing and elongated cutting member, the actuator causing the elongated cutting member to move about the Y-axis; and (vi) a programmable controller operably connected to the cutting tool and controlling movement of the cutting head or elongated cutting member in the Z-axis, W-axis, Y-axis, and rotation about the elongated cutting member's longitudinal axis; (b) from a surface location lowering the cutting tool into an innermost tubular of a plurality of nested tubulars; (c) engaging the anchoring system such that the tool body is anchored relative to the innermost tubular; (d) the second drive motor extending the cutting head to a first Z axis cutting position Z1; (e) the third drive motor causing the elongated cutting member to rotate about the rotational cutting axis; (f) the actuator causing the elongated cutting member to move to a first Y-axis arcuate position Y1; (g) while the elongated cutting member is at the Y1 arcuate angle, the second drive motor rotating the cutting head in the W-axis at least one complete revolution; (h) during step “g”, the second drive motor causing the cutting head to retract in the Z axis to a second Z-axis cutting position Z2, wherein Z2 is less than Z1; (i) after step “h”, the second drive motor extending the cutting head to a third Z axis cutting position Z3, wherein Z3 is greater than Z2; (j) after step “h”, the actuator causing the elongated cutting member to move to a second Y-axis arcuate position Y2, wherein Y2 is greater than Y1; (k) while the elongated cutting member is at the Y2 arcuate angle, the second drive motor rotating the cutting head in the W-axis at least one complete revolution; (l) after step “b”, and without raising the tool body to the surface location, completely severing the plurality of the nested tubulars with the elongated cutting member; and (m) inputting size information for each of a plurality of nested tubulars, and based on the inputted size information, the controller controlling steps “d” through “k”.

2. The method of claim 1, wherein during step “m”, for any of the tubulars to be cut, the controller accepts input regarding: a target Y-axis cutting position of the elongated cutting member relative to a preselected Y-axis home position.

3. The method of claim 1, wherein during step “m”, for any of the tubulars to be cut, the controller accepts input regarding target starting and finishing Z-axis cutting positions for the cutting head (e.g., for the tubular being cut to provide a desired finished gap or swath or cut), relative to a preselected Z-axis home position.

4. The method of claim 1, wherein during step “m”, for any of the tubulars to be cut, the controller accepts input regarding the diameters of the tubulars.

5. The method of claim 1, wherein during step “m”, for any of the tubulars to be cut, the controller accepts input regarding the thickness of the tubulars.

6. The method of claim 1, wherein during step “m”, for any of the tubulars to be cut, the controller accepts input regarding the eccentricity or out of roundness of the tubulars.

7. The method of claim 1, wherein during step “m”, for any of the tubulars to be cut, the controller accepts input regarding the amount of offset of one or the tubulars related to another tubular.

8. The method of claim 1, wherein the controller is operably connected to a display, and, based on input regarding the nested tubulars to be cut, the controller determines and displays on the display target values for one or more of the nested tubulars to be cut, and the user can override one or more target values for movements in Y-axis (e.g., target cutting position for a particular tubular), Z-axis (e.g., starting and finishing Z-axis locations for a particular tubular), W-axis (e.g., angular rotational speed), and/or ECMLAR (e.g., angular rotational speed).

9. The method of claim 1, wherein the controller is operably connected to a display, and, based on input regarding the nested tubulars to be cut, the controller displays on the display a pictorial representation of the cuts which will be made in the plurality of nested tubulars by the elongated cutting member.

10. The method of claim 9, wherein the pictorial display made on a tubular by tubular basis.

11. The method of claim 10, wherein an operator is provided an option to select which of the set of tubulars a pictorial display will be made.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:

(2) FIG. 1 shows a schematic view of a rig which has collapsed with a wellbore that will be abandoned.

(3) FIG. 2 shows a plurality of nested tubulars from the wellbore of FIG. 1.

(4) FIGS. 3A and 3B are sectional diagrams of one embodiment of controlled cutting apparatus which can be used in the method and apparatus.

(5) FIG. 4 is an enlarged view of the cutting head of the cutting apparatus of FIG. 1.

(6) FIG. 4A is a schematic view of the milling bit from the cutting head of FIG. 4.

(7) FIG. 5 is a side view of one embodiment of a controlled cutting apparatus which can be used in the method and apparatus

(8) FIG. 6 is an enlarged side sectional view of the cutting head of the cutting apparatus of FIG. 5.

(9) FIG. 7 is an enlarged front view of the cutting head of the cutting apparatus of FIG. 5.

(10) FIG. 8 is an enlarged side view of the cutting head of the cutting apparatus of FIG. 5, taken from the opposing side as that shown in FIG. 6.

(11) FIG. 9 is a schematic view of packer system which can be used by the cutting apparatus of FIG. 5 (shown in the collapsed or non-anchored condition)

(12) FIG. 10 is a schematic view of packer system which can be used by the cutting apparatus of FIG. 5 (shown in the expanded or anchored condition)

(13) FIG. 11 is a schematic view of a vessel lowering the controlled cutting apparatus of FIG. 5 into a plurality of nested tubulars to be cut at least a specified depth below the sea floor.

(14) FIG. 12 is a schematic front view of the controlled cutting apparatus of FIG. 11 after being lowered into an anchoring position for a plurality of nested tubulars of FIG. 1 (only one tubular shown for clarity) to be cut at least a specified depth below the sea floor.

(15) FIG. 13 is a schematic side view of the controlled cutting apparatus of FIG. 11 after being lowered into an anchoring position for a plurality of nested tubulars of FIG. 1 (only one tubular shown for clarity) to be cut at least a specified depth below the sea floor.

(16) FIG. 14 is a schematic front view of the controlled cutting apparatus of FIG. 11 after being lowered into an anchoring position for a plurality of nested tubulars of FIG. 1 (now with all three of the tubulars showny) to be cut at least a specified depth below the sea floor.

(17) FIG. 15 is a view schematically showing the beginning of the cut made by the cutting apparatus of FIG. 11 in the first tubular.

(18) FIG. 16 is an enlarged view of the cutting head portion of the cutting apparatus shown in FIG. 15.

(19) FIG. 17 is a view schematically showing the end of the cut made by the cutting apparatus of FIG. 11 in the first tubular.

(20) FIG. 18 is an enlarged view of the cutting head portion of the cutting apparatus shown in FIG. 17.

(21) FIG. 19 is a view schematically showing the beginning of the cut made by the cutting apparatus of FIG. 11 in the second tubular, after having completed the cut in the first tubular.

(22) FIG. 20 is an enlarged view of the cutting head portion of the cutting apparatus shown in FIG. 19.

(23) FIG. 21 is a view schematically showing the end of the cut made by the cutting apparatus of FIG. 11 in the second tubular, after having completed the cut in the first tubular.

(24) FIG. 22 is an enlarged view of the cutting head portion of the cutting apparatus shown in FIG. 21.

(25) FIG. 23 is a view schematically showing the cut made by the cutting apparatus of FIG. 11 in the third tubular, after having completed the cuts in the first and second tubulars.

(26) FIG. 24 is an enlarged view of the cutting head portion of the cutting apparatus shown in FIG. 23.

(27) FIG. 25 is a view schematically showing the cutting apparatus of FIG. 11 being pulled up after having completed the cuts in the first, second, and third tubulars.

(28) FIG. 26 is an enlarged view of the cutting head portion of the cutting apparatus shown in FIG. 25.

(29) FIG. 27 is a schematic view of the three nested tubulars which were cut by the cutting apparatus of FIG. 11 (where these tubulars were concentrically positioned).

(30) FIG. 28 is a schematic view of the three nested tubulars which were cut by the cutting apparatus of FIG. 11 (where these tubulars were eccentrically positioned).

(31) FIG. 29 is a schematic view of the three cut nested tubulars being pulled out of the well bore so that the well can be properly abandoned.

(32) FIG. 30 is a schematic view of one embodiment of a display which can show in substantially real time a schematic representation of the cutting head and the cut or cuts made in one or more nested tubulars, shown in the beginning of a cut of the first nested tubular.

(33) FIG. 31 is a schematic view of one embodiment of a display which can show in substantially real time a schematic representation of the cutting head and the cut or cuts made in one or more nested tubulars, shown in the middle of a cut of the first nested tubular.

(34) FIG. 32 is a schematic view of one embodiment of a display which can show in substantially real time a schematic representation of the cutting head and the cut or cuts made in one or more nested tubulars, shown in the beginning of a cut of the second nested tubular, after completing the cut of the first nested tubular.

(35) FIG. 33 is a schematic view of one embodiment of a display which can show in substantially real time a schematic representation of the cutting head and the cut or cuts made in one or more nested tubulars, shown in the middle of a cut of the second nested tubular, after completing the cut of the first nested tubular.

(36) FIG. 34 depicts the robotic rotary mill cutter of one embodiment.

(37) FIGS. 35A and 35B, depict the upper and lower portions, respectively, of the robotic rotary mill cutter.

(38) FIG. 36 depicts an expanded view of an inserted carbide mill of one embodiment.

(39) FIG. 37A depicts a top view of multiple casings (tubulars) that are non-concentric.

(40) FIG. 37B depicts an isometric view of non-concentric casings (tubulars).

(41) FIG. 38A depicts a portion of the robotic rotary mill cutter as it enters the tubulars.

(42) FIG. 38B depicts a portion of the robotic rotary mill cutter as it is severing multiple casings.

(43) FIGS. 39A and 39B depict the upper and lower portions, respectively, of an alternative embodiment of the robotic rotary mill cutter.

(44) FIGS. 40A, 40B, and 40C depict side view, isometric view, and a bottom view of an alternative embodiment of a cutting device.

(45) FIGS. 41A and 41B depict embodiments of a steady rest attached to one embodiment of the robotic rotary mill cutter.

DETAILED DESCRIPTION

(46) Detailed descriptions of one or more preferred embodiments are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in any appropriate system, structure or manner.

(47) FIGS. 3A and 3B are sectional diagrams of one embodiment of controlled cutting apparatus 100 which can be used in the method and apparatus 10. FIG. 4 is an enlarged view of the cutting head 1000 of cutting apparatus 100.

(48) Generally cutting apparatus 100 can comprise body 500, cutting head 1000, and elongated cutting member 1500. Tool body 500 can support a supporting a drive system that includes a first motor W-axis drive 600 and a second motor Z-axis drive 300.

(49) Cutting apparatus 100 can include a reaction member 1800 which is attached to cutting head 1000. Reaction member 1800 can include a reaction bar having first 1810 and second ends 1820. On the second end can include a contact member 1830 which preferably is comprised of a material adequate to hand reaction forces expected to be encountered by the cutting member 1500 when cutting tubulars. Contact member 1830 is also preferably comprised of a material having a relatively small coefficient of friction to reduce reactional frictional forces on cutting head 1000 when the cutting head (and connected reaction member 1800) are moved in the Z axis direction during a cut. The length of reaction member 1800 (e.g., the length between first end 1810 and contact member 1830) is preferably long enough such that contact member 1830 will be below the lower end 77 of the cut in the first nested tubular.

(50) Cutting apparatus 100 can have, operably connected thereto, a remote control 4000 having a display 4100 from which an operator can program, initiate, control, and/or override one or more of the operations/functions of cutting apparatus 100, cutting head 1000, and/or cutting member 1500. Remote control 4000 can have one or more controls 190 operatively connected thereto.

(51) A collar 200 can be attached to body 500 of cutting apparatus 100. Referring to FIG. 3A, a collar 200 can be used to attach the umbilical cord, wireline, and other connecting items to the body of controlled cutting apparatus 100. Collar 200 may be exchanged to adapt to different size work strings (not shown). Additionally, collar 200 provides a quick disconnect point in case emergency removal of controlled cutting apparatus is necessary.

(52) The anchoring system 1100 can have engaged and non-engaged conditions (e.g., see expanded packer condition 1110), wherein during the engaged condition the tool body 500 is anchored relative to the tubular, and during the non-engaged position the tool body is not anchored relative to the tubular. After cutting apparatus 100 is lowered to a selected cutting location, an anchoring system, such as a hydraulic packer 1100, can be energized to anchor body 500 of cutter 100 into well bore 60. Other types of conventionally available anchoring systems can be used in place of or in addition to packer 1100. For example expandable and retractable arms can be used which expand from body 500 to contact the interior of the innermost nested tubular of a plurality of nested tubulars. An anchoring system 1100 allows controlled Z and W axis movement of cutting head 1000 (along with cutting member 1500). An anchoring system 1100 also allows controlled Y axis movement of cutting member 1500. An anchoring system also tends minimize harmful vibrations to cutting member 1500 during cuts.

(53) Elongated cutting member 1500 (for example, a carbide cutter) can be mounted to the milling spindle swing arm 1400, and can be pivoted out in the Y-axis by Y-axis hydraulic cylinder 1600 into the cut of a tubular member.

(54) Controllable Movement in Z-Axis

(55) Cutting head 1000 can be operably connected to body 500 such that cutting head 1000 can be controllably moved along a Z-axis. The cutting head 1000 can be coupled to the second motor drive 300, wherein the second motor drive 300 causes the cutting head 1000 to be selectively moved in the Z-axis relative to the tool body 500.

(56) The Z-axis control unit can comprise Z-axis motor 300 and controls, drive cylinder 320 having upper and/or lower threaded areas 322,324, and driving screw 400. In one embodiment motor 300 is attached to body 500 via mounting plate 350, and motor 300 rotates screw 400. Because screw 400 is threadably connected to drive cylinder 320 rotation of screw 400 will cause cylinder 320 to move in the direction of the Z-axis (in the direction of arrow 2010 or arrow 2020 depending on the direction of rotation of screw 400). Additionally depending on the speed of rotation of screw 400 (along with the pitch of the threads of screw 400 the speed of movement in the Z-axis can be controlled).

(57) Support bracket 370 connects drive cylinder 320 to W-axis motor 600. W-axis motor 600 is operably connected to cutting head tube 1010 through transmission 700, coupling 800 and rotary hydraulic coupling 900. Cutting head tube is connected to cutting head 1000. Cutting head tube 1010 is slidably connected to body 500 such that cutting head tube can, in the interior space of body 500, slide in the Z-axis (extending and retracting as desired) along with rotating in the W-axis relative to body 500. Cutting head 1000 can include elongated cutting member 1500 and Y-axis actuator 1600.

(58) In one embodiment transmission 700 can be a step down transmission with a 126:1 ration.

(59) Telescoping tubing 360 allow, during the extension and retraction of drive cylinder 320 an extending and retracting connection for fluid and/or electrical controls and/or sensor data to for components lower than mounting plate 350.

(60) Controllable Movement about W-Axis

(61) Cutting head 1000 can be operably connected to body 500 such that cutting head 1000 can be controllably rotated about a W-axis. The cutting head 1000 can be coupled to the first motor drive 600, wherein the first motor drive 600 causes the cutting head 1000 to be moved in the W-axis of rotation relative to the tool body 500.

(62) Controllable Movement in Y-Axis

(63) Elongated cutting member 1500 can be operably connected to cutting head such that cutting member 1500 can be controllably pivoted about a Y-axis. An arcuate actuator 1600 can be operatively connected to the spindle housing 1700, the actuator 1600 having actuator first 1610 and second 1620 end portions, the first end portion 1610 being mounted to the cutting head 1000 at an elevational position (at pivot 1612) which is below the first elevation (at pivot 1412), and at the other of its end portions 1620 being mounted (at pivot 1622) to the spindle housing 1400 at a position also below the first elevation (at pivot 1412), the actuator 1600 moving the spindle housing 1400 and elongated cutting member 1500 between first and second extreme arcuate positions (FIG. 3B and FIG. 4).

(64) Controllable Movement about Longitudinal Axis of Cutting Member

(65) Elongated cutting member 1500 can be operably connected to cutting head 1000 such that cutting member 1500 can be controllably rotated about an elongated cutting member's 1500 longitudinal axis. A third motor drive 1220 can be operably connected to the elongated cutting member 1500 causing the elongated cutting member 1500 to rotate about the elongated cutting member's longitudinal axis 1514 and relative to the spindle housing 1400. The speed of rotation and force of rotation can be controlled by motor 1220.

(66) The cutting head 1000 can include: a spindle housing 1400 pivotally connected to the cutting head 1000 at a pivot 1412, the pivot 1412 being located at a first elevation, the spindle housing 1400 having: (1) an elongated cutting member 1500 with distal 1520 and proximal ends 1510, and the elongated cutting member 1500 being rotationally connected to the spindle housing 14, the elongated cutting member 1500 having a longitudinal axis (axis of rotation 1514) spanning between its first 1510 and second 1520 ends, (2) the spindle housing 14 having a second lower distal end portion 1420 and first upper proximal end portion 1410, the upper proximal end portion 1410 being connected to the cutting head 1000 at the pivot 1412, the spindle housing 1400 and elongated cutting member 1500 being able to travel through an arcuate path (Y-axis) having first and second extreme arcuate positions, wherein the first extreme arcuate position (FIG. 3B) is more closely aligned with the Z-axis compared to the second extreme arcuate position (FIG. 4), and the second extreme arcuate position (FIG. 4) is more closely aligned with the W-axis compared to the first extreme arcuate position (FIG. 3B). Arrows 1414 schematically indicating pivoting about pivot 1412.

(67) FIG. 4A is a sectional view of the cutting bit 1500 separated from the cutting head 1000. Cutting bit 1500 comprises body 1505 having first end 1510 and second end 1520. Between first and second ends are a plurality of teeth 1530 which can spin about axis of rotation 1514 (arrow 1516 schematically indicating rotation about axis of rotation 1514, and spinning can occur in the opposite direction of arrow 1516).

(68) A vibration reduction system can be included in cutting bit 1500 which can comprise an opening 1508 in body 1505, wherein such opening 1508 is filled with heavy oil 1580. Cap 1570 can be threadably connected to body 1505 at second end 1520. Screw 1560 can be threadably connected to body 1505 at first end 1510. Screw 1562 can be threadably connected to cap 1570.

(69) Spanning opening 1508 can be bar 1540 (which can be kept under tension between screw 1560 and screw 1560) causing body 1505 of cutting bit 1500 to be kept under compression. Opening. Opening 1508 can be sealed by plunger 1550 having O-ring seals 1585 keeping heavy oil 1580 in opening 1508. The combination of heavy oil 1508 and tension of bar 1540 assists in reducing vibrations in cutting bit 1500 during cutting.

(70) In one embodiment body 1505 can be an alloy steel, bar 1540 can be tungsten, and plunger 1550 and cap 1570 can be aluminum bronze.

(71) One Embodiment of Method and Apparatus

(72) Below is included one embodiment of a method for using of cutting apparatus 100 for severing a plurality of nested tubulars 70 (which can be concentrically or eccentrically nested relative to each other), each tubular having a tubular bore, the nested tubulars being disposed in a well bore and wherein there is an outer tubular and an inner tubular inside the bore of the outer tubular, method comprising the steps of:

(73) (a) providing a cutting tool, the cutting tool including: (i) a tool body 500 configured to be lowered (such as by wireline 210) into the tubular bore of the innermost nested tubular, the tool body 5 having a longitudinal Z-axis, a W-axis of rotation generally perpendicular to the Z-axis, and an anchoring system 1100 attached to the tool body, the anchoring system 1100 having engaged and non-engaged conditions (e.g., see expanded packer condition 1110), wherein during the engaged condition the tool body 500 is anchored relative to the tubular, and during the non-engaged position the tool body is not anchored relative to the tubular; (ii) the tool body 500 including a cutting head 1000 movably connected to the tool body 500 in both the Z and W axes, the tool body 500 supporting a drive system that includes a first motor W-axis drive 600 and a second motor Z-axis drive 300; (iii) the cutting head 1000 being coupled to the first motor drive 600, wherein the first motor drive 600 causing the cutting head 1000 to be moved in the W-axis of rotation relative to the tool body 500; (iv) the cutting head 1000 being coupled to the second motor drive 300, wherein the second motor drive 300 causing the cutting head 1000 to be moved in the Z-axis relative to the tool body 500; (v) the cutting head 1000 including: a spindle housing 1400 pivotally connected to the cutting head 1000 at a pivot 1412, the pivot 1412 being located at a first elevation, the spindle housing 1400 having: (1) an elongated cutting member 1500 with distal 1520 and proximal ends 1510, and the elongated cutting member 1500 being rotationally connected to the spindle housing 14, the elongated cutting member 1500 having a longitudinal axis (axis of rotation 1514) spanning between its first 1510 and second 1520 ends, (2) the spindle housing 14 having a second lower distal end portion 1420 and first upper proximal end portion 1410, the upper proximal end portion 1410 being connected to the cutting head 1000 at the pivot 1412, the spindle housing 1400 and elongated cutting member 1500 being able to travel through an arcuate path (Y-axis) having first and second extreme arcuate positions, wherein the first extreme arcuate position (FIG. 3B) is more closely aligned with the Z-axis compared to the second extreme arcuate position (FIG. 4), and the second extreme arcuate position (FIG. 4) is more closely aligned with the W-axis compared to the first extreme arcuate position (FIG. 3B); (vi) an arcuate actuator 1600 operatively connected to the spindle housing 1700, the actuator having 1600 actuator first 1610 and second 1620 end portions, the first end portion 1610 being mounted to the cutting head 1000 at an elevational position (at pivot 1612) which is below the first elevation (at pivot 1412), and at the other of its end portions 1620 being mounted (at pivot 1622) to the spindle housing 1400 at a position also below the first elevation (at pivot 1412), the actuator 1600 moving the spindle housing 1400 and elongated cutting member 1500 between first and second extreme arcuate positions (FIG. 3B and FIG. 4); and (vii) a third motor drive 1220 operably connected to the elongated cutting member 1500 causing the elongated cutting member 1500 to rotate about the elongated cutting member's longitudinal axis 1514 and relative to the spindle housing 1400;

(74) (b) from a surface location lowering the cutting tool into an innermost tubular of a plurality of nested tubulars;

(75) (c) the third drive motor 1220 causing the elongated cutting member 15 to rotate about the rotational cutting axis 1514;

(76) (d) the actuator 1600 causing the rotational cutting axis 1514 to move between the first and second extreme arcuate angles (FIGS. 3B and 4 with rod 1640 respectively in retracted and extended conditions);

(77) (e) the second drive motor 600 rotating the cutting head 1000 in the W-axis;

(78) (f) after step “b” and before step “g” the third drive motor 300 moving the cutting head 17 in the Z axis (in the direction of arrow 380 either upwardly 2010 or downwardly 2020 by turning driving screw 400 to move driving nut 310); and

(79) (g) before raising the tool body 500 to the surface location 30, completely severing the plurality of the nested tubulars 70 with the elongated cutting member 1500.

(80) In the preferred embodiment, after anchoring body 500 of cutter 100, Z-axis motor 300 causes cutting head 1000 to move in the direction of arrow 2020 to a down position. Such initial downward movement of cutting head 1000 permits elongated cutting member 1500 to begin cutting at the lowest point of the cut (e.g., point 77 in tubular 75) and be raised (in the direction of arrow 2010) as needed to cause a depth of cut (e.g., depth 78 in tubular 75) sufficient to allow elongated cutting member 1500 access to make cuts in the larger nested tubulars (e.g., tubular 80, 85, etc.) of a plurality of nested tubulars 70.

(81) FIG. 1 shows a schematic view of a rig 40 which has collapsed with a wellbore 60 (along with a plurality of nested tubulars 70) that will be abandoned. Tubular is intended to be broadly construed to include pipe, tubing, casing, conduit, along with other cylindrical items that can be installed in a wellbore 60.

(82) FIG. 2 shows three nested tubulars 75, 80, and 85 of a plurality of nested tubulars 70 which are to be cut by cutting apparatus 100 (where these tubulars are concentrically positioned relative to each other). In various embodiments the tubulars can have in their annuluses between them combinations of cement and/or formation rock (although such is not shown in FIG. 2).

(83) In FIG. 2, riser 50 shown in FIG. 1 has been previously cut to a height “H” above sea floor 20 by conventionally available methods (such as wireline) to provide easy access to the interior of the innermost nested tubular 75. To properly abandon wellbore 60 the plurality of nested tubulars 70 must be cut to a depth D below sea floor 20 which exceeds regulatory requirements.

(84) FIGS. 3A and 3B are sectional diagrams of one embodiment of controlled cutting apparatus 100 which can be used in the method and apparatus 10.

(85) FIG. 4 is an enlarged view of the cutting head 1000 of cutting apparatus 100.

(86) FIG. 5 is a side view of one embodiment of a controlled cutting apparatus 100 which can be used in the method and apparatus 10. Cutting apparatus is shown in the state at which it will be lowered into the innermost nested tubular 75 for a cut. In this state cutting member 1500 is in its home position or the smallest Y-axis position (compared to the Z-axis). However, it should be noted that the home Y-axis position of cutting member 1500 is not zero degrees. Preferably, this home Y-axis position can 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 degrees from the Z-axis. In various embodiments the home Y-axis position can be a range between any two of the above stated home Y-axis positions. The cutting head is also shown in the home Z-axis position—where tube 1010 is maximally retracted into body 500 of cutting apparatus 100. The cutting head is also shown in the home W-axis which can be an arbitrarily chosen position in the W-axis because cutting apparatus 1000 will be lowered on line 210 by vessel 300, and while being lowered, cutting apparatus 1000 itself can rotate somewhat freely in the W-axis. After cutting apparatus has been put in the anchored state (such as by inflation of packer 1100 in tubular 75), relative movement of cutting head 1000 in the W-axis can be monitored and measured (i.e., when cutting apparatus is in place and anchored for a cut). In FIG. 5 hydraulic packer 1100 is shown deflated or in the non-anchored state.

(87) FIG. 6 is an enlarged side sectional view of cutting head 1000 of cutting apparatus 100 where cutting member 1100 is shown in the home or Y-axis retracted state. FIG. 7 is an enlarged front view of cutting head 1000 of cutting apparatus 100. FIG. 8 is an enlarged side view of cutting head 1000 of cutting apparatus 100 taken from the opposing side as that shown in FIG. 6. Arrow 1840 schematically indicates reaction force being placed on cutting head 1000 when cutting member 1500 moves out in the Y-axis direction. Such reaction force will tend to cause the body 500 of cutting apparatus to pivot about its anchor point (e.g., the place of anchor by packer 1100) in the direction of arrow 1840. Such pivoting is limited by contact surface 1830 of reaction member 1800 contacting innermost tubular 75 where such contact will cause an equal and opposing reaction force to be applied to contact member 1830 and body 500. In this manner reaction member 1800 helps stabilizing cutting apparatus 100 during a cut.

(88) FIG. 9 is a schematic view of packer system 1100 which can be used by cutting apparatus 100 (shown in the collapsed or non-anchored condition) to place cutting apparatus 100 in anchored and non-anchored states relative to the innermost nested tubular 75. FIG. 10 is a schematic view of packer system 1100 shown in the expanded or anchored condition.

(89) FIG. 11 is a schematic view of a vessel 3000 using crane 3050 to lower (schematically indicated by arrow 110) controlled cutting apparatus 100 into a plurality of nested tubulars 70 to be cut at least a specified depth “D” below sea floor 20. This is a schematic figure and not to scale. An operator can control cutting apparatus 100 using remote controller 4000, with controller having a display 4100 for ease of operation.

(90) FIG. 12 is a schematic front view of controlled cutting apparatus 100 after being lowered into an anchoring position for cutting a plurality of nested tubulars 70 (however, for clarity only one tubular 75 is shown for clarity) to be cut at least a specified depth “D” below sea floor 20. FIG. 13 is a schematic side view of controlled cutting apparatus 100 after being lowered into an anchoring position for cutting a plurality of nested tubulars 70 (however, for clarity only one tubular 75 is shown for clarity) to be cut at least a specified depth “D” below sea floor 20. FIG. 14 is a schematic front view of controlled cutting apparatus 100 after being lowered into an anchoring position for cutting a plurality of nested tubulars 70 (now with all three of the tubulars 75, 80, and 85 shown) to be cut at least a specified depth “D” below the sea floor 20. In these figures cutting head 1000 is fully retracted and in the home position in the Z axis (schematically indicated by Zh). Cutting head 1000 is also in the home position for the W axis; and cutting member 1500 is in the home position in the Y-axis

(91) FIGS. 15 through 18 schematically illustrate various steps using cutting apparatus 100 to make a cut in the first nested tubular 75 of the plurality of nested tubulars 70.

(92) FIG. 15 is a view which schematically shows the beginning of a cut being made by cutting apparatus 100 in first tubular 75. FIG. 16 is an enlarged view of cutting head portion 1000 of cutting apparatus 100 in the position shown in FIG. 15. In these figures cutting head 1000 has extended in the Z-axis from the home position (Zh) to the position to start the first cut (Z1). Also in these figures cutting member 1500 has pivoted from the home position in the Y axis to the Y-axis position Y1 to make the first cut (schematically indicated by Y1). While making the cut cutting member 1500 will be rotated about its longitudinal axis 1514 (schematically indicated by the arrow about axis 1514) at a controlled rotational speed. Also while making the cut cutting head 1000 will be rotated in the W-axis at a controlled rotational speed (schematically indicated by the W-arrow). Also while making this cut, cutting head 1000 will be pulled up in the direction of arrow 2010 along the Z-axis from Z-axis location Z1 to Z-axis location Z2. In this manner cutting member 1500 will traverse an upward helical or spiral pathway cutting a swath in the tubular.

(93) FIG. 17 is a view schematically showing the end of a cut being made by cutting apparatus 100 in the first tubular 75. FIG. 18 is an enlarged view of cutting head 1000 portion of cutting apparatus 100 in the position shown in FIG. 17. While making this cut, cutting head 1000 was pulled up in the direction of arrow 2010 along the Z-axis from Z-axis location Z1 to Z-axis location Z2 (which is more retracted compared to position Z1). Now a swath or cut has been made in nested tubular 75 from bottom 77 to top 76 making a gap 78. It is noted that in FIG. 18 length 1850 of reaction arm 1800 is shown where contact member 1830 loses contact with tubular 75 as cutting head 1000 is retracted along the Z-axis (to position Z2). It is preferable that length 1850 is long enough so that contact member will maintain contact during the retracting process of the first cut. However, continuous contact of contact member 1830 may not be as important (compared to tubulars 80, 85, etc) for cutting the first tubular 75 because the first tubular will have the smallest diameter and the smallest vibration issues (compared to larger tubulars 80, 85, etc).

(94) FIGS. 19 through 22 schematically illustrate various steps using cutting apparatus 100 to make a cut in the second nested tubular 80 of the plurality of nested tubulars 70.

(95) FIG. 19 is a view which schematically showing the beginning of a cut being made by cutting apparatus 100 in second tubular 80, after having completed the cut in the first tubular 75 (with a cut depth 78 in the first tubular 75). FIG. 20 is an enlarged view of cutting head 1000 portion of cutting apparatus 100 in the position shown in FIG. 19. In these figures cutting head 1000 has extended in the Z-axis from the home position (Zh) to the position to start the first cut (Z3). Also in these figures cutting member 1500 has pivoted to the Y-axis position Y2 to make the second cut (schematically indicated by Y2). While making the cut cutting member 1500 will be rotated about its longitudinal axis 1514 (schematically indicated by the arrow about axis 1514) at a controlled rotational speed. Also while making the cut cutting head 1000 will be rotated in the W-axis at a controlled rotational speed (schematically indicated by the W-arrow). Also while making this cut, cutting head 1000 will be pulled up in the direction of arrow 2010 along the Z-axis from Z-axis location Z3 to Z-axis location Z4. In this manner cutting member 1500 will traverse an upward helical or spiral pathway cutting a swath in tubular 80.

(96) FIG. 21 is a view schematically showing the end of cut being made by cutting apparatus 100 in the second tubular 80, after having completed the cut in the first tubular 75 (with a cut depth 78 in the first tubular 75). FIG. 22 is an enlarged view of cutting head 1000 portion of cutting apparatus 100 in the position shown in FIG. 21. While making this cut, cutting head 1000 was pulled up in the direction of arrow 2010 along the Z-axis from Z-axis location Z3 to Z-axis location Z4 (which is more retracted compared to position Z3). Now a swath or cut has been made in nested tubular 80 from bottom 82 to top 83 making a gap 84. It is noted that in FIG. 22 length 1850 of reaction arm 1800 is shown where contact member 1830 does not lose contact with tubular 75 as cutting head 1000 is retracted along the Z-axis (from position Z3 to position Z4).

(97) FIGS. 23 and 24 schematically illustrate various steps using cutting apparatus 100 to make a cut in the third tubular 85 of the plurality of nested tubulars 70.

(98) FIG. 23 is a view schematically showing a cut being made by cutting apparatus 100 in the third tubular 85, after having completed the cuts in the first and second tubulars (with a cut depth 78 in the first tubular 75, and a cut depth 83 in the second tubular 80). FIG. 24 is an enlarged view of cutting head 1000 portion of cutting apparatus 100 in the position shown in the FIG. 23. In these figures cutting head 1000 has extended in the Z-axis from the home position (Zh) to the position to start the first cut (Z5). Also in these figures cutting member 1500 has pivoted to the Y-axis position Y3 to make the second cut (schematically indicated by arrow Y3). While making the cut cutting member 1500 will be rotated about its longitudinal axis 1514 (schematically indicated by the arrow about axis 1514) at a controlled rotational speed. Also while making the cut cutting head 1000 will be rotated in the W-axis at a controlled rotational speed (schematically indicated by the W-arrow). Also while making this cut, in one embodiment, cutting head 1000 will be pulled up in the direction of arrow 2010 along the Z-axis from Z-axis location Z5 to Z-axis location Z6. In this manner cutting member 1500 will traverse an upward helical or spiral pathway cutting a swath in tubular 85. In one embodiment cutting head 1000 is maintained at a constant position Z5 and cutting member 1500 makes a cut through tubular 85 (and no spiral motion is seen by cutting member 1500).

(99) FIG. 25 is a view schematically showing cutting apparatus 1000 being pulled up (schematically indicated by arrow 2010) after having completed the cuts in the first 75, second 80, and third 85 tubulars—completely severing the plurality of nested tubulars 70 (with a cut depth 78 in the first tubular 75, a cut depth 83 in the second tubular 80, and a cut depth 87 in the third tubular 85). FIG. 26 is an enlarged view of cutting head 1000 portion of cutting apparatus 100 in the position shown in FIG. 25. The upper portions of the plurality of the plurality of nested tubulars 70 now ready to be pulled out of wellbore 60. In these figures cutting head 1000 has been retracted to its home position in the Z-axis (to Zh), and cutting member 1500 has also been pivoted in the Y-axis to its home position. Additionally, hydraulic packer 1100 has been released causing cutting apparatus to enter a non-anchored state. Cutting apparatus 100 is now in a condition to be pulled up by vessel 3000 in the direction of arrow 2010 to the surface.

(100) In one embodiment from the beginning of the cut of the first tubular 75 to the completion of the cut of the outermost tubular 85, cutting apparatus remained below the surface of the water 30. In one embodiment, during this time cutting apparatus remained in well bore 60. In one embodiment, cutting apparatus remained anchored in a single position in innermost tubular 75.

(101) Concentric Tubulars

(102) FIG. 27 is a schematic view of the three nested tubulars 75, 80, and 85 of a plurality of nested tubulars 70 which were cut by cutting apparatus 100 (where these tubulars were concentrically positioned). In various embodiments the tubulars can have in their annuluses between them combinations of cement and/or formation rock.

(103) Tubular 75 cut has upper level 76 and lower level 77, with a height or swath of cut 78. Tubular 80 cut has upper level 81 and lower level 82, with a height or swath of cut 83. Tubular 85 cut has upper level 86 and lower level 87, with a height or swath of cut 88.

(104) In one embodiment height of cut 78 is larger than height of cut 83, and height of cut 83 is larger than height of cut 88. In one embodiment lower level 77 is lower than lower level 83, and lower level 83 is lower than lower level 87. In one embodiment upper level 76 is higher than upper level 81, and upper level 81 is higher than upper level 86. In one embodiment lower level 77 is equal to lower level 83, and lower level 83 is equal to lower level 87.

(105) In one embodiment height of cut 78 is larger than height of cut 83, and height of cut 83 is larger than height of cut 88. In one embodiment lower level 77 is lower than lower level 83, and lower level 83 is lower than lower level 87. In one embodiment upper level 76 is higher than upper level 81, and upper level 81 is higher than upper level 86.

(106) In one embodiment lower level 77 is about equal to lower level 83, and lower level 83 is about equal to lower level 87 (and Z1 is about equal to Z3 and Z3 is about equal to Z5).

(107) Eccentric Tubulars

(108) FIG. 28 is a schematic view of the three nested tubulars 75, 80, and 85 of a plurality of nested tubulars 70 which were cut by cutting apparatus 100 (where these tubulars were eccentrically positioned). In various embodiments the tubulars can have in their annuluses between them combinations of cement and/or formation rock. In various embodiments the tubulars can have in their annuluses between them combinations of cement and/or formation rock.

(109) Tubular 75 cut has upper level 76 and lower level 77, with a height or swath of cut 78. Tubular 75 cut also has upper level 76′ and lower level 77′, with a height or swath of cut 78′. Tubular 80 cut has upper level 81 and lower level 82, with a height or swath of cut 83. Tubular 80 cut also has upper level 81′ and lower level 82′, with a height or swath of cut 83′. Tubular 85 cut has upper level 86 and lower level 87, with a height or swath of cut 88. Tubular 85 cut also has upper level 86′ and lower level 87′, with a height or swath of cut 88′. In one embodiment height of cut 78 is larger than height of cut 83, and height of cut 83 is larger than height of cut 88. In one embodiment height of cut 78′ is larger than height of cut 83′, and height of cut 83′ is larger than height of cut 88′. In one embodiment lower level 77 is lower than lower level 83, and lower level 83 is lower than lower level 87. In one embodiment lower level 77′ is lower than lower level 83′, and lower level 83′ is lower than lower level 87′. In one embodiment upper level 76 is higher than upper level 81, and upper level 81 is higher than upper level 86. In one embodiment upper level 76′ is higher than upper level 81′, and upper level 81′ is higher than upper level 86′. In one embodiment lower level 77 is equal to lower level 83, and lower level 83 is equal to lower level 87. In one embodiment lower level 77′ is equal to lower level 83′, and lower level 83′ is equal to lower level 87′.

(110) FIG. 29 is a schematic view of the upper portions 75′, 80′, and 85′ of the three cut nested tubulars 70 being pulled out of well bore 60 so that the wellbore can be properly abandoned. Now from the sea floor 20 to the top of the remaining plurality of nested tubulars 70 is at least a depth D.

(111) FIG. 30 is a schematic view of one embodiment of a display 4100 showing (in substantially real time) a schematic representation of relative movement of the cutting head 1000 and the cut or cuts made in one or more nested tubulars of a plurality of nested tubulars 70, shown in the beginning of a cut of the first nested tubular 75. FIG. 31 is a schematic view of one embodiment of a display 4100 showing (in substantially real time) a schematic representation of relative movement of the cutting head 1000 and the cut or cuts made in one or more nested tubulars of a plurality of nested tubulars 70, shown in the middle of a cut of the first nested tubular 75.

(112) Estimated Sample Times and W-Axis Times for Cuts

(113) Below are provided some sample estimated cutting times and number of W-axis rotations required for cutting particular sized nested tubulars with the method and apparatus.

(114) TABLE-US-00001 TABLE 1 SAMPLE OF ESTIMATED CUTTING PROFILES/TIMES TWO TUBULARS 1.sup.st size W-REV 2.sup.nd SIZE W-REV TOTAL W-REV EST. TIME 9⅝″ 7 13⅝″ 1 8 4 MIN 9⅝″ 16 24″ 1 17 9 MIN 9⅝″ 18 30″ 1 19 10 MIN 

(115) TABLE-US-00002 TABLE 2 SAMPLE OF ESTIMATED CUTTING PROFILES/TIMES 3 TUBULARS 1.sup.st SIZE/ WREV 2.sup.nd SIZE/W-REV 3.sup.rd SIZE/W-REV TOTAL EST. TIME 9⅝″/12 13⅜″/6 20″/1 19 10 MIN

(116) In one embodiment cutter 100 has tool body 500 pressurized with nitrogen with the advantage of pressurization is that changes in temperature in the well formation do not create condensation inside the tool body while the tool is inside the well formation.

(117) In one embodiment, how far in the Z-axis (Z1) cutting head 1000 goes down depends on the outer diameter of the outermost nested tubular to be cut.

(118) In one embodiment the rate of feed in the Z-axis is equal to 2 inches per revolution of the cutting head in the W-axis- or 2 inches per W axis revolution.

(119) Display for Cut of Innermost Tubular

(120) Looking at FIGS. 31 and 32 an operator can have a pictorial representation on display 4100 viewing a three dimensional the graphical depiction of the cut being made, along with the relative movements of cutting head 1000 and cutting member 1500 about the Y, Z, and W axes on such display. One can also visualize the swath or cut made in the innermost nested tubular 75 having a gap 78′. FIG. 31 shows cutting head 1000 and cutting member 1500 in a second position for W and Z axes (the Y-axis position remained the same). FIG. 31 also schematically depicts the cut made in tubular 75 from the position shown in FIG. 30 to the position shown in FIG. 31. The relative Y, Z, and W axial positions of cutting head 1000 and cutting member 1500 can be obtained from sensor and positional information and/or data from cutting apparatus 100.

(121) Display for Cut of Second Tubular

(122) FIG. 32 is a schematic view of one embodiment of a display 4100 showing (in substantially real time) a schematic representation of relative movement of the cutting head 1000 and the cut or cuts made in one or more nested tubulars of a plurality of nested tubulars 70, shown in the beginning of a cut of the second nested tubular 80, after completing the cut of the first nested tubular 75. FIG. 33 is a schematic view of one embodiment of a display 4100 showing (in substantially real time) a schematic representation of relative movement of the cutting head 1000 and the cut or cuts made in one or more nested tubulars of a plurality of nested tubulars 70, shown in the middle of a cut of the second nested tubular 80, after completing the cut of the first nested tubular 75.

(123) Looking at FIGS. 32 and 33 an operator can have a pictorial representation on display 4100 viewing a three dimensional the graphical depiction of cut being made in the second tubular 80 (along with the cut already made in the first tubular 75), along with the relative movements of cutting head 1000 and cutting member 1500 about the Y, Z, and W axes on such display. The operator can also see the swath or cut made in the second tubular 80 having a gap 81′. FIG. 33 shows cutting head 1000 and cutting member 1500 in a second position for W and Z axes (the Y-axis position remained the same Y2). FIG. 33 also schematically depicts the cut made in tubular 80 from the position shown in FIG. 32 to the position shown in FIG. 33 (along with the completed cut in the innermost tubular 75). The relative Y, Z, and W axial positions of cutting head 1000 and cutting member 1500 can be obtained from sensor and positional information and/or data from cutting apparatus 100.

(124) Viewing of cuts in third, fourth, etc. tubulars can similarly be displayed on display 4100 of controller 4000. For example, with three nested tubulars 75, 80, and 85, a cut (cut or swath 87′) in the third tubular 85 could be displayed on display 4100 with swaths or cuts already shown for the first and second tubulars (first tubular having completed swath or cut 78 and second tubular having completed watch or cut 83).

(125) The following is a table listing the various reference numerals used in this application and a description of each. Note that this table describes only the reference numerals for FIGS. 1 through 33. In later figures, similar or identical parts may be identified by different numerals.

(126) TABLE-US-00003 TABLE OF REFERENCE NUMERALS AND DESCRIPTIONS Reference Description 10 method and apparatus 20 sea floor 30 water surface 40 oil and gas rig 44 collapsed portion 48 remaining support structure 50 riser 60 well bore 70 plurality of nested tubulars 75 first tubular 76 upper portion 77 lower portion 78 height of cut 80 second tubular 81 upper portion 82 lower portion 83 height of cut 85 third tubular 86 upper portion 87 lower portion 88 height of cut 100 apparatus 110 arrow 190 controls 200 collar 210 wireline 300 Z-axis motor and controls 310 driving nut 320 drive cylinder 350 mounting plate or bracket for Z-axis motor 360 telescoping tubing 370 support bracket 380 vertical arrows 400 driving screw 500 tool body or housing 510 interior space 600 W-axis motor 700 transmission system 800 coupling 900 rotary hydraulic coupling 1000 cutting head (connected to W-axis rotating body and Z-axis movable bar) 1010 cutting head tube 1100 packer (for anchoring system) 1110 packer in expanded condition 1120 expanding arrows 1130 connection point for packer 1200 milling spindle swing arm 1220 motor for cutting bit 15 1300 pivot bearing 1400 milling spindle swing arm housing 1404 wall 1410 first end 1412 pivot point 1420 second end 1424 arrows 1500 cutting bit 1505 body 1508 opening or bore 1510 first end 1514 axis of rotation 1516 arrow schematically indicating rotation about axis of rotation 1520 second end 1530 milling bit teeth 1540 bar (under tension) 1550 plunger 1560 socket head cap screw 1562 socket head cap screw 1570 cap 1580 heavy oil 1585 O-ring seals 1600 Y axis hydraulic cylinder 1610 first end 1612 pivot point 1620 second end 1622 pivot point 1630 cylinder 1634 arrows schematically indicating ability to pivot 1640 rod 1644 arrows schematically indicating the ability to extend and retract 1700 connection housing to W-axis rotating body 1710 first end 1720 second end 1800 reaction bar 1810 first end 1820 second end 1830 contact surface 1840 reaction bending force arrow 2000 step of lowering 3000 vessel 3010 surface of vessel 3020 control area 3050 crane 4000 remote controller 4100 display H height above sea floor D depth of cut below sea floor

(127) All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.

(128) It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention set forth in the appended claims. The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.

(129) Although described with reference to specific embodiments, one skilled in the art could apply the principles discussed herein to other areas and/or embodiments.

(130) Throughout this disclosure casing(s) and tubular(s) are used interchangeably.

(131) This invention provides a method and apparatus for efficiently severing installed tubing, pipe, casing, and liners, as well as cement or other encountered material in the annuli between the tubulars, in one trip into a well bore.

(132) Reference will now be made in detail to the present embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts (elements).

(133) To help understand the advantages of this disclosure the accompanying drawings will be described with additional specificity and detail.

(134) The method generally is comprised of the steps of positioning a robotic rotary mill cutter inside the innermost tubular in a pre-selected tubular or plurality of multiple, nested tubulars to be cut, simultaneously moving the rotary mill cutter in a predetermined programmed vertical X-axis, and also 360 degree horizontal rotary W-axis, as well as the spindle swing arm in a pivotal Y-axis arc.

(135) In one embodiment of the present disclosure the vertical (Z axis) and horizontal (W axis) movement pattern(s) and the spindle swing arm (Y axis) are capable of being performed independently of each other, or programmed and operated simultaneously in conjunction with each other. The robotic rotary mill cutter is directed and coordinated such that the predetermined pattern is cut through the innermost tubular beginning on the surface of said tubular, with the cut proceeding through it to form a shape or window profile(s), or to cut through all installed multiple, nested tubulars into the formation beyond the outermost tubular by making multiple passes and cutting away layer by layer of tubulars and cement until the largest (outermost) nested tubular has been severed.

(136) In one embodiment of the present disclosure the robotic rotary mill cutter, will cut from the inside of a 8.5 inch tubular and cut away layer by layer nested tubulars and cement thus generating larger and larger voids, that will allow the Y-axis milling spindle swing arm (see 5014 of FIG. 39B) and cutting device (see 5015 of FIG. 39B) progressively greater swing angles and reach. In three to four passes of cutting away layer by layer of nested tubulars (see FIG. 38B) and cement as above, the cutting device 5015 can cut away tubulars and cement inside a 42-inch diameter circle.

(137) A profile generation system simultaneously moves the robotic rotary mill cutter in a vertical Z-axis, and a 360-degree horizontal rotary W-axis, and the milling spindle swing arm (see 5014 of FIG. 39B) in a pivotal Y-axis arc to allow cutting the tubulars, cement, and formation rock in any programmed shape or window profile(s).

(138) The robotic rotary mill cutter apparatus is programmable to simultaneously or independently provide vertical X-axis movement, 360-degree horizontal rotary W-axis movement, and spindle swing arm pivotal Y-axis arc movement under computer control. A computer having a memory and operating pursuant to attendant software, stores shape or window profile(s) templates for cutting and is also capable of accepting inputs via a graphical user interface, thereby providing a system to program new shape or window profile(s) based on user criteria. The memory of the computer can be one or more of but not limited to RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, floppy disk, DVD-R, CD-R disk or any other form of storage medium known in the art. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC or microchip.

(139) The computer controls the profile generation servo drive systems as well as the cutting device speed. The robotic rotary mill cutter requires load data to be able to adjust for conditions that cannot be seen by the operator. The computer receives information from torque sensors (see 5052, and 5053 of FIGS. 35A and 35B) attached to Z-axis, W-axis, Y-axis, and milling spindle drive motor, and makes immediate adaptive adjustments to the feed rate and speed of the vertical Z-axis, the 360 degree horizontal rotary W-axis, the spindle swing arm pivotal Y-axis and the RPM of the milling spindle motor.

(140) Software in communication with sub-programs gathering information from the torque devices, such as a GSE model Bi-Axial transducer Model 6015 or a PCB model 208-M133, directs the computer, which in turns communicates with and monitors the downhole robotic rotary mill cutter and its attendant components, and provides feeds and speeds simultaneously or independently along the vertical Z-axis, the 360 degree horizontal rotary W-axis, as well as the pivotal spindle swing arm Y-axis arc movement.

(141) The shape or window profile(s) are programmed by the operator using a program logic controller (PLC), or a personal computer (PC), or a computer system designed or adapted for this specific use. The integrated software via a graphical user interface (GUI) or touch screen, such as a Red Lion G3 Series HMI, accepts inputs from the operator and provides the working parameters and environment by which the computer directs and monitors the robotic rotary mill cutter.

(142) In the preferred embodiment, the vertical Z-axis longitudinal computer-controlled servo axis uses a hydraulic cylinder, such as the Parker Series 2HX hydraulic cylinder, housing the MTS model M-series absolute analog sensor for ease of vertical Z-axis longitudinal movements, although other methods may be employed to provide up and down vertical movement of the robotic rotary mill cutter.

(143) In a still further embodiment of the present disclosure the vertical Z-axis longitudinal computer-controlled servo axis may be moved with a ball screw and a computer controlled electric servo axis motor, the Fanuc D2100/150 servo, with encoder feedback to the computer system by an encoder (see 5050 in FIG. 35A) such as the BEI model H25D series incremental optical encoder. Servomotors and ball screws are known in the art and are widely available from many sources.

(144) In a still further embodiment of the present disclosure the vertical Z-axis longitudinal computer-controlled servo axis may be moved with a ball screw and a hydraulic motor, such as a Parker TC0045, with encoder feedback to a motion controller, similar to a Galil DMC-21X3 series motion controller, that operates a hydraulic servo valve, similar to a Parker Series DY12 servovalve, or hydraulic proportional valve, that powers the hydraulic motor. Servo valves, proportional valves, and motion controllers are known in the art and are widely available from many sources.

(145) In a still further embodiment of the present disclosure, the vertical Z-axis longitudinal computer-controlled servo axis may be moved with a rack and pinion, either electrically or hydraulically driven. Rack and pinion drives are known in the art and are widely available from many sources.

(146) In the preferred embodiment, the rotational computer controlled W-axis rotational movement is an electric servomotor, The rotational computer-controlled W-axis servomotor, such as a Fanuc model D2100/150 servo, provides 360-degree horizontal rotational movement of the robotic rotary mill cutter through a specially manufactured slewing gear.

(147) In a still further embodiment of the present disclosure, the rotational computer controlled W-axis rotational movement is controlled by a hydraulic servo valve that drives a hydraulic motor coupled to the W-axis and has a sensor position feedback encoder connected to the rotational computer controller for closed loop servo operation.

(148) Closed loop servo hydraulic drives are a known art and are widely available from many sources.

(149) Also in the preferred embodiment, the Y-axis pivotal milling spindle swing arm computer-controlled servo axis uses a hydraulic cylinder for ease of use, although other methods may be employed. The Y-axis pivotal milling spindle swing arm computer-controlled servo axis, may utilize the Parker Series 2HX hydraulic cylinder, housing the MTS model M-series absolute analog sensor (see 5051 in FIG. 35B) inside the hydraulic cylinder to provide position feedback to the computer controller for pivotal spindle swing arm Y-axis arc movement.

(150) In a still further embodiment of the present disclosure an inertia reference system such as, Clymer Technologies model Terrella6 v2, can provide information that the robotic rotary mill cutter is actually performing the movements sent by the computer controller as a verification reference. The Clymer Technologies model Terrella6 v2 is mounted in the milling spindle swing arm (see 5014 in FIG. 39B) and provides temperature and vibration monitoring to the operators display monitor in real time where that information will be used by the operator to make feed and speed adjustments for best cutting operations. If the reference shows a sudden stop, or any axis is not responding to the programmed feeds and speeds the computer can go into a hold action stopping the robotic rotary mill cutter and requiring operator intervention before resuming milling operations. Alarms may be visually shown on the operator's monitor and/or may have an audible warning.

(151) The methods and systems described herein are not limited to specific sizes, shapes, or models. Numerous objects and advantages of the disclosure will become apparent as the following detailed description of the multiple embodiments of the apparatus and methods of the present disclosure are depicted in conjunction with the drawings and examples, which illustrate such embodiments.

(152) FIG. 34 depicts the robotic rotary mill cutter 5001. The robotic rotary mill cutter 5001, shows the position of the vertical Z-axis, and the 360-degree horizontal rotary W-axis, and the Y-axis pivotal milling spindle swing arm.

(153) FIGS. 35A and 35B, depict the upper and lower portions, respectively, of the robotic rotary mill cutter of the preferred embodiment.

(154) Referring to FIG. 35A, a collar 5002 is used to attach the umbilical cord (not shown) and cable (not shown) to the body of robotic rotary mill cutter 5001. Collar 5002 may be exchanged to adapt to different size work strings (not shown). Additionally, the collar 5002 provides a quick disconnect point in case emergency removal of the robotic rotary mill cutter 5001 is necessary. In one embodiment, the collar 5002 may be a spring centralizer about three feet long. After the robotic rotary mill cutter 5001 is in the cut location, locking hydraulic cylinders 5003 are energized to lock the robotic rotary mill cutter 5001 into the well bore (not shown). In the preferred embodiment, after the locking hydraulic cylinders 5003 have been energized, Z-axis hydraulic cylinder 5006 is moved to a down position by extending piston rod 5004 allowing the Z-axis slide 5005 to extend. This permits the robotic rotary mill cutter 5001 to begin cutting at the lowest point of the cut and be raised as needed to complete the severance.

(155) Referring to FIG. 35B, additional locking hydraulic cylinders 5007 are available should additional stabilization (if energized) or movement (if not energized) is desired. W-axis servomotor 5008 rotates the W-axis rotating body 5010 under control of the computer (not shown). W-axis rotating body 5010 houses the milling spindle swing arm 5014 and the milling spindle swing arm 5014 is driven by motor 5011 also housed in the W-axis rotating body 5010. Milling spindle swing arm 5014 is driven by motor 5011 through a half-shaft 5012 such as Motorcraft model 6L2Z-3A427-AA.

(156) Half-shaft 5012 has a C.V. joint (not shown) that allows milling spindle swing arm 5014 to pivot in an arc from pivot bearing 5013 that goes through W-axis rotating body 5010. Milling spindle swing arm 5014 is moved by Y-axis hydraulic cylinder 5016. The rotation of W-axis rotating body 5010 requires a swivel joint 5009, such as Rotary Systems, Inc. Model DOXX multiple-passage rotary union, to allow power and sense lines (not shown) to motor 5011, Y-axis hydraulic cylinder 5016, and load cell 5054 sense wires (not shown). Cutting device 5015 (for example, carbide milling cutter or solid carbide cutter) is mounted to the milling spindle swing arm 5014 and is moved by Y-axis hydraulic cylinder 5016 into the cut under computer control.

(157) FIG. 36 depicts an expanded view of one embodiment of an inserted carbide mill 5017 that could be attached to milling spindle swing arm 5014. Other milling units with different material and/or cutting orientation could be utilized depending on the particular characteristics of the severance to be performed.

(158) FIG. 37A depicts a top view of nested multiple casings (tubulars) 5018 that are positioned non-concentrically.

(159) FIG. 37B depicts an isometric view of nested multiple casings (tubulars) 5018 that are positioned non-concentrically.

(160) FIG. 38A depicts a portion of the robotic rotary mill cutter 5001 as it enters the nested multiple casings (tubulars) 5018.

(161) FIG. 38B shows the nested multiple casings (tubulars) 5018 with the void that has been created by the robotic rotary mill cutter 5001. The profile generation system (not shown) simultaneously moved the robotic rotary mill cutter 5001 in a vertical Z-axis, and a 360-degree horizontal rotary W-axis, and the milling spindle swing arm 5014 in a pivotal Y-axis arc to allow cutting of the tubulars, cement (not shown), and formation rock (not shown) in any programmed shape or window profile(s) thereby cutting through the multiple casing (tubulars) 5018, cement (not shown) or other encountered material in casing annuli (not shown) by making multiple successfully larger voids created by the robotic mill cutter as above.

(162) FIGS. 39A and 39B depict the upper and lower portions, respectively, of an alternative embodiment of the robotic rotary mill cutter. Referring first to FIG. 39A, the Z-axis motor 5060 rotates the ball screw 5062 through the Z-axis nut 5064, which raises or lowers the remainder of the tool. A trombone slide 5066 resides on either side of the ball screw 5062. The trombone slide 5066 is hollow and carries pressured hydraulic fluid to the remainder of the tool. The trombone slide 5066 is capable of containing and transmitting hydraulic fluid pressurized to around 1,000 lbs/in.sup.2. The W-axis hydraulic motor drives rotation about the Z-axis (W-axis rotation). Anti-torque rails (not shown) stop the tool from rotating when the ball screw 5062 is rotated. Additionally, tie rods 5068 provide support for the W-axis transmission 5070.

(163) The W-axis transmission 5070 rotates the drive bar 5076 within the packer 5078 thereby providing rotation about the Z-axis (W-axis rotation). In one embodiment, a transmission is employed. In one embodiment, the transmission is a cluster gear transmission. The transmission is used because of the size and power constraints (e.g. relatively small size and relatively high power). Additionally, in one embodiment, the hydraulic fluid is returned through the W-Axis transmission for lubrication of the transmission 5070. The shaft coupling 5072 couples the W-axis transmission 5070 to the rotary coupling 5074 that couples to the drive bar 5076. The rotary coupling 5074 also provides a path for the hydraulic fluid to pass to the remainder of the tool. In one embodiment, the space between the drive bar 5076 and the packer 5078 is filled with pressurized hydraulic fluid (up to around 1,000 lbs/in.sup.2). This hydraulic fluid acts as an anti-vibration device. Bearings may also be employed between the drive bar 5076 and the packer 5078 to reduce vibration and center the drive bar 5076. The packer 5078 can be fitted with additional bushings (not shown) to accommodate different size tubulars. Furthermore, the packer 5078, when pressurized expands/inflates against the wellbore to provide additional stability and vibration reduction. Additionally, for larger wellbores, a spacer or sleeve can be attached about the tool (relatively near the packer) to act a centralizer until the packer has expanded/inflated to impact the innermost tubular. In yet another embodiment, a spacer or sleeve could even be placed about the packer to more closely match the inner diameter of a wellbore before expanding/inflating the packer.

(164) Occasionally a tear or other obstruction or flow anomaly may occur in the fluid delivery lines of a downhole cutter. Traditionally, the level of a large fluid tank, for example hydraulic fluid, would be monitored. If the level started decreasing, then the operators knew there was a problem. Unfortunately, this routinely occurs only after some significant amount of fluid is lost downhole (e.g. 20-30 gallons). Furthermore, the operators only know there is a problem but; they have no idea which hose had the leak.

(165) Contrary to traditional models, in addition to the traditional “level” monitoring, each hose to and from the tool is fitted with turbine flow meters to continuously monitor the flow of fluid through each hose. This provides a very early warning system to alert operators to any flow anomalies. For example, should a hose develop a tear and begin leaking fluid into the wellbore, the “delivery” hose would have a flow rate in excess of the “return” hose. If the difference in the flow meters exceeded a defined threshold, an operator could be alerted. This is an improvement over traditional fluid “level” monitoring which could only detect tears after a significant amount of fluid was lost downhole, wasting money and creating potential environmental hazards. Further, traditional “level” monitoring could only detect flow anomalies that resulted in the loss of fluid. By utilizing turbine flow meters, pinched, partially blocked/clogged, and/or completely blocked/clogged hoses can be detected. Also, because each hose has its own turbine flow meter, the operator can immediately identify which hose is having the flow anomaly and how serious the flow anomaly is.

(166) The spindle housing 5080 is rigidly attached to the drive bar 5076 such that as the drive bar 5076 rotates, the spindle housing 5080 also rotates in the W-axis (about the Z-axis). This rotation can occur while the drive bar 76 is moved longitudinally (up and down along the Z-axis) by the action of the ball screw 5062. The spindle hydraulic motor 5082 rotates the shaft 5084 and the cutting device 5015. Although indicated as separate items, in one embodiment the shaft 5084 and the cutting device 5015 are made from the same piece of material. This provides the advantage of increased strength and vibration reduction with no connections between the shaft 5084 and the cutting device 5015. Finally, the Y-axis hydraulic cylinder 5016 swings the cutting device 5015 away from the spindle housing 5080.

(167) In one embodiment the ratio of shaft 5084 length to cutting device 5015 length is 1:1 to increase the strength of the assembly and reduce vibrations. In another embodiment, the cutting device 5015 may swing away from the spindle housing 5080 to an angle of 45 degrees (measured from the vertical center line of the spindle housing 5080 to the center line of the cutting device 5015) by the extension of the hydraulic cylinder 5016; however a wider angle is also achievable.

(168) Additionally, in one embodiment, a pressure relief hose (not shown) is attached to the Y-axis hydraulic cylinder 5016. This pressure relief hose has a valve (not shown) located at the surface that when actuated releases the pressure from the Y-axis hydraulic cylinder 5016. This could be used for example to allow the cutting device 5015 to retract back (see FIG. 39B) within the spindle housing 5080 should a hydraulic or electrical failure occur while the tool is deployed downhole and cutting. Without such a failsafe pressure relief, if the tool failed while cutting, the cutting device 5015 could be extended so far into the formation as to interfere with tool recovery. The pressure relief hose and valve are independent of any electronics on the tool itself or within the wellbore; therefore, a failure on the tool itself will not interfere with the failsafe pressure relief because it is controlled solely from the surface. Another such independent pressure relief hose (not shown) and valve (not shown) is attached to the packer for similar reasons.

(169) In one embodiment, the Y-axis hydraulic cylinder 5016 is capable of providing over 10,000 lbs of force.

(170) FIGS. 40A, 40B, and 40C depict side view, isometric view, and a bottom view of an alternative embodiment of the cutting device 5015. The shaft 5084 has notches 5100 to enable a sensor (e.g. proximity switch) to monitor the cutting device's 5015 rotational speed. The cutting device of this embodiment has 84 milling inserts 5104 (although alternate numbers of milling inserts 5104 could be used with success). In this particular embodiment, the milling inserts 5104 are arranged in 6 rows of 14; however, alternative configurations could be used with success. Each of the milling inserts 5104 are mounted on individual insert faces 5106 and are removable in case of breakage or wear. The milling inserts 5104 extend partially above the insert faces 5106 to mill away the material being cut.

(171) Each milling insert 5104 has a life expectancy of about 15 minutes of cutting. By careful technique and using a milling insert 5104 layout and number similar to that disclosed herein, one can make the milling inserts last on the cutting device 5015 for about two hours of cutting (e.g. each milling insert 5104 sees less than 15 minutes of actual cut time during a two hour cutting episode). It is important to note that milling through the steel tubulars degrades the milling inserts 5104; therefore, to maximize cutting potential, the cutting of the steel tubulars is apportioned across the entire cutting device 5015.

(172) This technique of spreading the tubular cutting across the entire cutting device 5015 is accomplished by making the first cut only using the lower most milling inserts 5104 of the cutting device 5015 for a short period of time by feeding the cutting device 5015 out with hydraulic cylinder 5016 completely through the innermost tubular. Once the cutting device 5015 is through the innermost tubular, the spindle housing 5080 is rotated 360-degrees severing the first tubular. After the first tubular is severed, the spindle housing 5080 is raised vertically up the Z-axis while simultaneously rotating in the W-axis to spiral mill cut the innermost tubular the height required to remove the innermost tubular. For example, this would remove the first tubular and a small portion of the cement between the first tubular and the second tubular. When the first upward cut is complete, the spindle housing 5080 would be lowered back down along the Z-axis to the start position of the first cut and the Y-axis hydraulic cylinder 5016 would move the cutting device 5015 further into the nested tubulars now that the innermost first tubular has been removed. The next cut would use milling inserts 5104 further up the cutting device 5015 to cut the tubulars as the spindle housing 5080 is then feed vertically up the Z-axis a height programmed while simultaneously rotating in the W-axis to spiral mill cut the length of the next tubular and cement.

(173) This technique is repeated until the final cut. The remaining life of the lower most inserts 5104 are reserved to make the final cut through the tubular that is the farthest into the formation, as the lower most milling inserts are used mostly for cutting cement until the final cut. By continuing in this manner, the tubular cutting is spread across the entire cutting device 5015 to maximize the cutting ability.

(174) Additionally, this embodiment acts as a type of pump, directing the fluid flow into the wellbore while ejecting any chips or debris resulting from the cutting process down the wellbore. This ejecting action is accomplished by orienting the troughs 5108 between the rows of inserts 5104 backwards (e.g. reverse cutter) and rotating the rotary mill cutter 5015 clockwise. Traditional cutters are oriented with a “forward” cutter.

(175) Traditional systems have to feed pressurized lubricant from the surface into the bearing assemblies or use sealed bearings. In contrast, this embodiment has a lubricant hole 5110 in the shaft 5084 that traverses from the outside of the shaft 5084 to the inside opening 5112 which allows lubricant to flow onto the shaft 5084 and coat the shaft 5084 to reduce friction as the rotary mill cutter 5015 and shaft 5084 rotates. The rotary mill cutter 5015 and the shaft 5084 contain pressurized lubricant in a reservoir. A piston (not shown) is attached to an opening 5112 in the base of the rotary mill cutter 5015 to pressurize the lubricant. When the shaft 5084 is connected to the spindle hydraulic motor 5082 a seal is created below the lubricant hole 5110 such that the lubricant does not leak. When the cutting device 5015 needs to be serviced, the lubricant can be changed by removing the piston. By filling the rotary mill cutter 5015 with pressurized lubricant, additional vibration reduction can be achieved.

(176) Unlike traditional cutters this embodiment has no connection point between the shaft 5084 and the cutting device 5015 (e.g. it is made from a single piece of metal). This increases the strength and decreases the complexity thereby making this embodiment more reliable than traditional cutters.

(177) In one embodiment the cutting device 5015 measures approximately one foot in length and approximately four inches in diameter, however other lengths and diameters could be employed depending on the particular application. Also in this embodiment, the insert face 5106 is angled about nine degrees off the centerline, although other angles could also be employed depending on the particular application.

(178) FIGS. 41A and 41B depict the tool with the steady rest 5120. The steady rest 5120 provides an offset point to reduce vibration, provide stability for the cutting device 5015, and counteract the force of the cutting device 5015 pushing against the tubulars and/or formation. As such, the steady rest is positioned such that it impacts the wellbore on the opposite side from the arcing motion of the spindle swing arm 5014. Additionally, the steady rest 5120 provides a safety mechanism in case one or more tubulars shifts during cutting.

(179) It is not uncommon for tubulars to shift during cutting for example if the tubular was not cemented well. These shifts could pin the tool in the wellbore and make retrieval difficult or impossible. In one embodiment, the steady rest 5120 is coupled to the tool with shear bolts 5121 and 5122 and extends below the cutting device 5015. In one embodiment there are two levels of shear bolts. If the first level of shear bolts 5121 gives way, the steady rest 5120 will shift inward (e.g. the steady rest pivots out of the way of the shifting tubular. This would represent a minor shift in the tubular. If this occurs, the tool and the steady rest are still retrievable. If the second level of shear bolts 5122 gives way, which represents a significantly more violent shift, the steady rest will separate from the spindle housing 5080 and the steady rest 5120 will remain in the wellbore; however, the robotic rotary mill (downhole assembly) would still be retrievable.

(180) The steady rest bearing 5123 provides the third major contact point between the tool and the wellbore. The first being the exposed portion of the spindle swing arm 5014 while cutting the first innermost tubular, the second being the milling spindle housing 5080 rubbing on the first innermost tubular as the mill cutter 5015 is cutting the first innermost tubular, and the third being the steady rest bearing 5123. These three major points of contact provide a very stable cutting platform and significantly reduce unwanted vibration.

(181) In one embodiment, the steady rest 5120 is about 42″ long. This permits the steady rest to engage against the inner wall of the innermost tubular for the majority, if not all, of the cut. In other embodiments, the steady rest 5120 may be more or less than 42″ long. In order to make cuts with a vertical distance (e.g. along the Z-axis) in excess of 54″ (e.g. 42″ travel with the steady rest engaged+12″ for the length of one embodiment of the cutting device 5015 itself): (i) a longer steady rest 5120 could be employed, (ii) the top most 54″ of the cut may be completed, then the tool repositioned about 54″ below the bottom of the first cut to begin a new series of cuts; (iii) the steady rest 5120 could be engaged against the innermost tubular wall only for a portion of the cut (e.g. the first cut, because it is generally the longest cut, could have some portion of its cut made without the steady rest 5120 engaged); and/or (iv) a longer rotary mill cutter 5015 could be used. It is preferable for the largest diameter cuts that the steady rest be engaged against the innermost wall.

(182) In one embodiment, the steady rest is not used if the cutting device 5015 vibrations are small. The Clymer Technologies model Terrella6 v2 (not shown) provides vibration graphical displays to the operators monitor (not shown).

(183) The disclosed subject matter covers the scope of functionality in a holistic way. Although described with reference to particular embodiments, those skilled in the art, with this disclosure, will be able to apply the teachings in principles in other ways. All such additional embodiments are considered part of this disclosure and any claims to be filed in the future.