Large diameter water well control

Abstract

A large diameter injection water well is drilled using a drilling derrick and rotary drilling techniques after snubbing in and drilling a short distance with drilling mud, a temporary drilling header is installed below the blowout preventers. Extending downward from the temporary drilling header is a drop pipe with a valve on the lower end thereof. Drilling pipe with attachments on the lower end thereof, are lowered into the drop pipe with the valve closed. After sealing to the drilling pipe, the valve is opened and the drilling pipe and attachments are lowered to the bottom of the well for the normal drilling operation. Thereafter, the drilling pipe and attachments are removed reversing the process of retracting into the drop pipe and closing the valve before removing the seal from the drilling pipe. The repeated insertion of the drilling pipe with various attachments on the end thereof in the drilling procedure occurs without having to kill or suppress the well until the final step when removing the drop pipe.

Claims

1. A process for drilling a water injection well using a drilling derrick with rotary drilling, including a rotary table, drill pipe, attachments, and blowout preventer, initially using drilling mud, a source of power outside said injection well, said process including the following steps: (a) drilling a first hole with said drill pipe and said drilling derrick; (b) snubbing in a casing having a diameter smaller than said hole; (c) drilling a first pilot hole below the lower end of said casing; (d) installing a temporary well header below said rotary drive and said blowout preventors; (e) attaching a drop pipe to an underside of said temporary well header, which drop pipe extends downward therefrom, diameter of said drop pipe being larger than said attachments but less than said casings; (f) said drop pipe having a valve secured on a lower end of said drop pipe; (g) pivotally connecting an actuator to said valve to open or close a bottom opening in said drop pipe, said actuator being opened or closed by said source of power from outside said injection well; (h) lowering said drill pipe and attachments into said drop pipe with said valve being closed; (i) securing said rotary drive and stripper rubber to said drill pipe above said temporary well header; (j) opening said valve with said actuator; (k) repeatedly extending said drill pipe and attachments into said pilot hole for as needed testing; (l) repeatedly retracting said drilling pipe and attachment back into said drop pipe during said testing; (m) closing said valve with said actuator; (n) killing said well and removing said temporary well header; (o) removing said drilling pipe, attachment and drop pipe; (p) reinserting said drilling pipe to drill a reduced diameter casing hole to receive a reduced diameter casing therein; (q) cementing said reduced diameter casing; (r) repeating steps (c) through (q) for each successively smaller diameter casing being inserted therein.

2. The process for drilling a water injection well as recited in claim 1 wherein said actuator is a hydraulic cylinder pivotally connected to said valve to open or close said bottom opening, said hydraulic cylinder being operated by hydraulic fluid provided by said source of power.

3. The process for drilling a water injection well as recited in claim 2 wherein during repeating steps (c)-(q) drilling of a second pilot hole occurs through said reduced diameter casing and testing in said second pilot hole occurs without killing or suppressing said water injection well until said second pilot hole is drilled and said needed testing is complete.

4. The process for drilling a water injection well as recited in claim 3 wherein during repeating steps (c)-(q) drilling of a third pilot hole occurs through a second reduced diameter casing, and testing in said third pilot hole occurs without killing or suppressing said water injection well until said second pilot hole is drilled and said needed testing is complete.

5. The process for drilling a water injection well as recited in claims 3 or 4 wherein during repeating steps (c)-(q) logging equipment is lowered through said drop pipe to run logs of said water injection well, said logging occurring without killing or suppressing said water injection well.

6. The process for drilling a water injection well as recited in claims 3 or 4 wherein during said repeating steps core sampling equipment is lowered through said drop pipe to take samples in said pilot holes of said injection well as it is being drilled, said sampling occurring without killing or suppressing said water injection well.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a pictorial illustration of a prior art oil drilling rig.

(2) FIG. 2 is a simplified, partial, cross-sectional view of the upper portion of a large diameter injection water well being drilled.

(3) FIG. 3 is an illustrative sectional view of the underground portion of a large diameter injection water well.

(4) FIG. 4 is a partial, cross-sectional view of the upper portion of a large diameter injection water well with a hydraulically actuated valve opening or closing a lower end of a drop pipe.

(5) FIG. 5 is a partial, cross-sectional view of the upper portion of a large diameter injection water well having a drop pipe with a bottom hole assembly therein prior to opening a lower valve.

(6) FIG. 6 is a partial, cross-section of the upper portion of a large diameter injection water well with a bottom hole assembly extending through a drop pipe and a lower valve into lower portions of the large diameter injection water well.

DESCRIPTION OF THE PREFERRED EMBODIMENT

(7) Before explaining the present invention, an explanation as to how an oil well is drilled is helpful. Referring to FIG. 1, a simplified pictorial representation of an oil field derrick 10 drilling an oil well 12 in the earth's surface 14 is shown. A mud tank 16 holds a drilling mud, such as barite, which may be delivered via a suction line 18 to mud pump 20, through vibrating hose 22, standpipe 24, kelly hose 26, goose necks 28, swivel 30 to Kelly drive 32. From the Kelly drive 32, the drilling mud travels through the rotary table 34 and drilling floor 36 to the drill string 38. However, before reaching the drill string 38, the drilling mud must travel through bell nipple 40, an angular blowout preventer 42, and ram blowout preventers 44.

(8) While FIG. 1 shows a rotary table 34, a tophead rotary drive may be used. Either one uses rotary drive to turn the drill string 38.

(9) As the rotary table 34 turns the drill string 38 drilling mud from the mud tanks 16 is delivered under pressure through drilling string 38 to the drill bit 46. As the oil well 12 is drilled deeper, derrick 48 uses traveling block 50 and crown block 52 to add additional drill pipes from the stand 54 of drill pipes, which stand 54 holds the pipe rack 56 by monkey board 58. As additional pipe is added to the drill string 38, flow of the mud from the mud tank 16 is stopped. The weight of the drilling mud will keep pressures inside the oil well 12 from blowing out the top of the oil well 12. Blow out preventers 42 and 44 also ensure that pressures inside of the oil well 12 will not escape.

(10) Mud from the mud tank 16 flows into the oil well 12 by flowing downward through the drill string 38. The mud returns between the drill string 38 and the well 12 being drilled in the earth simultaneously carrying any cuttings to the surface. The returning mud and cuttings flows through flow line 60 to a shell shaker 62 for removal of cuttings before returning the mud to the mud tank 16.

(11) Motor 64 with draw works 66 operate drill lines 68 to move traveling block 50 and rotate crown block 52 when adding more pipe from stand 54 to the drill string 38. This is a simplified description of how an oil well is drilled using standard techniques.

(12) In the drilling of the large diameter disposal water wells, similar techniques are used during the drilling process. A large diameter disposal water well that might be drilled in central or southern Florida would typically be snubbed in with a 54 inch steel casing 70. See FIG. 3. After the 54 inch steel casing 70 is cemented into place, mud will continue to flow through the drill string 38. See FIG. 1. Subsequently, a 44 inch steel casing 72 will have to be installed and cemented into place down to approximately 1000 feet in depth. Through the cementing in place of the 44 inch steel casing 72, drilling mud may be used, which drilling mud is pumped down through a drill string 38 and up through the annulus back to the surface. Everything through this point is the same as the prior art except there are larger diameters and lower pressures.

(13) Upon setting the 44 steel casing 72 into place the drilling mud is removed and a temporary drilling header 74 is installed. See FIG. 2. The temporary drilling header 74 is located below the blowout preventers 42 and 44. See FIG. 1. The next step in drilling the disposal water well is to drill a pilot hole approximately twelve inches in diameter to approximately two-thousand feet. The temporary drilling header 74 is normally installed after the drilling of the pilot hole. Typically, three or four core samples will be needed when drilling from 1000-2000 feet in depth. This requires tripping the drill string 38 out of the well 76. To prevent artesian flow therefrom, the well 76 will have to be either suppressed or killed. As the drill string 38 is removed from the well 76 as shown in FIG. 2, stripper rubber 78 will remove material from the drill string 38. On the bottom of the drill string 38 is located bottom hole assembly 80. The bottom hole assembly 80 may be a drill bit, packer, coring bell, a logging device, etc. However, the bottom hole assembly 80 normally cannot get past the rubber stripper 78 and/or temporary drilling header 74 nor past the rotary table 34. In the past, each time the bottom hole assembly 80 has to come out of the well 76, pressures inside the well 76 have to be either killed or suppressed. Previously, to kill or suppress pressures inside of the well 76 required a large amount of barite or salt to mix into a drilling mud. It is expensive and time consuming to have to kill or suppress the well using large amount of salt or barite. When drilling operations are to be resumed, the drilling mud or slurry will need to be reduced and/or removed from the well 76. The weight of the slurry/drilling mud prevents artesian flow from well 76.

(14) To prevent having to repeatedly kill the well 76, the temporary drilling header 74 has been modified so that a drop pipe 82 extends downward from the temporary drilling header 74. See FIG. 4. While the length of the drop pipe 82 may vary, it is estimated that drop pipe would be approximately two hundred feet in length. The drop pipe 82 is attached at the upper end to temporary drilling header 74. Flanges 84 are welded, or threaded connections may be used to add the necessary length to the drop pipe.

(15) On the lower end of the drop pipe 82 is located a valve 86 that is pivotally mounted on pivot pin 88. The operation of the hydraulic cylinder 90 causes valve 86 to be opened or closed. Hydraulic fluid for the hydraulic cylinder 90 is provided through hydraulic hoses 92. Each end of the hydraulic cylinder 90 is free to pivot on pivot pins 94 and 96. If the valve 86 is closed, a rubber sealing element 98 prevents leakage through the drop pipe 82.

(16) Referring to FIGS. 5 and 6 in combination, the present invention will be illustrated in further detail. In FIG. 5 the well 76 is being drilled into the earth 14. The initial steel casing 70 has been snubbed in into position and cemented in place. The 44 steel casing 72 (See FIG. 3) may, or may not, need suppression while it is being installed. A temporary drilling header 74 is installed at the top of the steel casing 70. The drop pipe 82 extends downward from the temporary drilling header 74. In the FIG. 5 hydraulic cylinder 90 has closed the valve 86 located at the bottom of the drop pipe 82. With the valve of 86 closed, drill pipe 38 along with bottom hole assembly 80 are lowered into the drop pipe 82. The upper part of the drill pipe 38 is sealed with the stripper rubber 78 and turned by rotary table 34.

(17) Pressure inside of the well 76 does not need to be suppressed or killed when inserting drill string 38 and bottom hole assembly 80 because valve 86 is closed with rubber sealing 98 preventing leakage there through. After the bottom hole assembly 80 is inside of drop pipe 82, then stripper rubber 78 and rotary table 34 are secured to the drill string 38. By opening the valve 86 with the hydraulic cylinder 90, the drill string 38 and the bottom hole assembly 80 can be lowered to the bottom of well 76. The bottom hole assembly 80 can include drill bit for drilling the hole deeper or a drill collar. The bottom hole assembly 80 can include coring equipment to get core samples. For injection water wells in Florida, it is important to run logging tools into the pilot holes.

(18) With the use of the drop pipe 82 just as described in FIGS. 5 and 6, numerous trips can be made into the well 76 without having to kill or suppress the well. Pilot holes can be drilled and logged. Smaller 34 steel casing 100, and 24 steel casing 102 can be installed and cemented in place using tremie tubing (not shown). It is only necessary to kill or suppress the well 76 one time[; namely, when] after the drop pipe 82 is [being] removed following [at] the final completion of each successive steel casing 72, 100 and 102, respectively, of the well 76.