Combined crushing super-variable-diameter drill bit for natural gas hydrate exploitation

Abstract

The present invention relates to a combined crushing super-variable-diameter drill bit for natural gas hydrate exploitation, including a joint, an outer cylinder connected to the joint by thread, a nozzle I mounted in the outer cylinder, a mechanical locking mechanism, a blade telescoping mechanism, an end cap connected to the outer cylinder by thread, a seal ring IV mounted to the end cap, and a nozzle II mounted in the end cap by threaded connection. The present invention achieves integrated operation of conventional drilling and draw-back expanding, which can effectively solve the problems that the existing hydrate drill bit cannot drill a large borehole, cannot mechanically lock an extending position of the blade to stabilize the size of the borehole, and a single crushing method is inefficient.

Claims

1. A combined crushing super-variable-diameter drill bit for natural gas hydrate exploitation, comprising: a joint (1), an outer cylinder (2) connected to the joint (1) by thread, a nozzle I (17) mounted in the outer cylinder (2), a mechanical locking mechanism, a blade telescoping mechanism, an end cap (13) connected to the outer cylinder (2) by thread, a seal ring IV (12) mounted to the end cap (13), and three nozzles II (18) mounted in the end cap (13) by threaded connection, wherein an upper portion of the outer cylinder (2) is provided with a seal ring groove I (201), a middle-upper portion of the outer cylinder (2) is provided with a step I (202), three raised jaws (203) are circumferentially distributed in a middle portion of the outer cylinder (2), a seal ring groove II (204) is disposed below the jaws (203), three sets of nozzle holes I (205) are circumferentially disposed below the seal ring groove II (204), there are 4 holes for each set of the nozzle holes I (205), a seal ring groove III (206) is disposed below the nozzle holes I (205), three rectangular through holes (207) are circumferentially disposed in a middle-lower portion of the outer cylinder (2), a lower portion of the rectangular through holes (207) is provided with a chute (209), and a step II (208) is disposed in an inner lower portion of the outer cylinder (2); the mechanical locking mechanism comprises a pressure cylinder (3), a seal ring I (4), a spring I (5), a jaw sleeve (6), a seal ring II (7), and a seal ring III (8), an upper end of the pressure cylinder (3) abuts a lower end face of the joint (1) positioned above the pressure cylinder (3), the seal ring I (4) is disposed between the pressure cylinder (3) and the outer cylinder (2), the spring I (5) is located in the outer cylinder (2) and two ends thereof are respectively connected between a step III (302) of the pressure cylinder (3) and the step II (208) inside the outer cylinder (2), the pressure cylinder (3) is in contact with the jaw sleeve (6), and the seal ring II (7) and the seal ring III (8) are disposed between the jaw sleeve (6) and the outer cylinder (2); the blade telescoping mechanism comprises a thrust ball bearing (9), a sliding cylinder (10), a spring II (11), a plurality of blades (14), a secondary crushing connecting rod (15), and a blade connecting base (16), the thrust ball bearing (9) is mounted between the jaw sleeve (6) and the sliding cylinder (10), the sliding cylinder (10) is in clearance fit with the jaw sleeve (6), the spring II (11) is connected between the sliding cylinder (10) and the step II (208) in the outer cylinder (2), the blade connecting base (16) is connected to the sliding cylinder (10) by bolt, upper and lower ends of the secondary crushing connecting rod (15) are respectively connected to one of the plurality of blades (14) and the outer cylinder (2) by bolt, the plurality of blades (14) are connected to the blade connecting base (16) by bolt, wherein the upper end of the secondary crushing connecting rod (15) is provided with a through hole III (1501), a left side of the secondary crushing connecting rod (15) is provided with two rows of raised crushing teeth (1502) and two rows of notches (1503), each row of the crushing teeth (1502) being adjacent to one of the two rows of notches (1503) and the two rows of notches (1503) being symmetrically arranged relative to the two row of crushing teeth (1502), the lower end of the secondary crushing connecting rod (15) is provided with a through hole IV (1504), and a groove I (1505) is disposed in the middle of the secondary crushing connecting rod (15), to make the secondary crushing connecting rod (15) take the shape of a fork; an upper end of the end cap (13) is provided with a seal ring groove IV (1301) for receiving the seal ring IV (12), the middle of the end cap (13) is provided with a step V (1302), and the end cap (13) is circumferentially provided with three nozzle holes II (1303); and the nozzles II (18) are mounted in the nozzle holes II (1303) in the end cap (13), wherein in one of the nozzle holes II (1303) one of the nozzles II (18) is mounted.

2. The combined crushing super-variable-diameter drill bit for natural gas hydrate exploitation according to claim 1, wherein in the mechanical locking mechanism, the pressure cylinder (3) is provided with a necked step opening (301), the step III (302), three recesses (303), and three helical surfaces I (305), the necked step opening (301) is disposed on the inside of the pressure cylinder (3), the step III (302) is disposed on the outside of the pressure cylinder (3), the three recesses (303) are disposed along a circumferential direction of an outer wall of the pressure cylinder (3), the three helical surfaces I (305) are disposed at a lower end of the pressure cylinder (3), and three sections (304) are disposed on the three helical surfaces I (305); an upper end of the jaw sleeve (6) is provided with six helical surfaces II (601), three sections (602), three gaps (603), and a step IV (604), the three sections (602) and the three gaps (603) are intersected between every two helical surfaces II (601), and the step IV (604) is disposed in the middle of the jaw sleeve (6); and the recesses (303) match with the jaws (203), and the helical surfaces I (305) on the pressure cylinder (3) are in contact with the helical surfaces II (601) on the jaw sleeve (6).

3. The combined crushing super-variable-diameter drill bit for natural gas hydrate exploitation according to claim 1, wherein in the blade telescoping mechanism, each of the plurality of blades (14) comprises a through hole I (1401), cutting teeth (1402), flat teeth (1403), a through hole II (1404), a triangular groove (1405), flat teeth (1406), and ball teeth (1407), the through hole I (1401) is disposed on an upper end of one of the plurality of blades (14), the cutting teeth (1402) are uniformly disposed along edges of one of the plurality of blades (14), two rows of flat teeth (1403) are disposed on an outer side of one of the plurality of blades (14), the through hole II (1404) is disposed in a middle portion of one of the plurality of blades (14), the triangular groove (1405) is disposed on one of the plurality of blades (14), the flat teeth (1406) of the plurality of blades (14) are disposed a lower outer side of the plurality of blade (14), and the ball teeth (1407) are disposed at a lower ends of the plurality of blade (14); the blade connecting base (16) is provided with a bolt through hole (1601), a through hole V (1602), and a groove II (1603); the blade connecting base (16) is connected to the sliding cylinder (10) through a bolt through hole (1601) by using a bolt, the through hole I (1401) is connected to the through hole V (1602) by bolt, to make the plurality of blades (14) connected to the blade connecting base (16), the through hole II (1404) is connected to the through hole III (1501), to make the middle portions of the plurality of blades (14) connected to the secondary crushing connecting rod (15), and the secondary crushing connecting rod (15) is connected to the outer cylinder (2) through the through hole IV (1504).

4. The combined crushing super-variable-diameter drill bit for natural gas hydrate exploitation according to claim 1, wherein when the device is drilling, the plurality of blades (14) are closed, front ends of plurality of blades (14) form a drill bit to drill forward, and the nozzle II (18) assists in crushing; when the drill bit drills to the end of a hydrate layer, the plurality of blades (14) begin to open, and the nozzle I (17) on the outer cylinder (2) is opened while the blades (14) are opened, to achieve hydrate hydraulic crushing; after the plurality of blades (14) are opened, the plurality of blades (14) are combined in an umbrella shape, and the drill bit begins to draw back, in which case the plurality of blades (14) rotate to crush the hydrate to achieve mechanical crushing of the hydrate; the secondary crushing connecting rod (15) rotates while the plurality of blades (14) rotate, the crushing teeth (1502) and the notches (1503) on the secondary crushing connecting rod (15) coordinate with each other to continue to crush the hydrate to achieve secondary mechanical crushing of the hydrate.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is an external view of the present invention;

(2) FIG. 2 is a comparison diagram of contraction and extension of a blade according to the present invention;

(3) FIG. 3 is a schematic structural diagram of an outer cylinder according to the present invention;

(4) FIG. 4 is a schematic structural diagram of a pressure cylinder according to the present invention;

(5) FIG. 5 is a schematic structural diagram of a jaw sleeve according to the present invention;

(6) FIG. 6 is a schematic structural diagram of an end cap according to the present invention;

(7) FIG. 7 is a schematic structural diagram of a blade according to the present invention;

(8) FIG. 8 is a schematic structural diagram of a secondary crushing connecting rod according to the present invention;

(9) FIG. 9 is a schematic structural diagram of a blade connecting base according to the present invention;

(10) FIG. 10 is a schematic view of a drilling operation of a drill bit according to the present invention;

(11) FIG. 11 is a schematic view of a draw-back operation of the drill bit according to the present invention; and

(12) FIG. 12 is a schematic enlarged view of positions of the drill bit during the draw-back operation according to the present invention.

(13) In the figures, 1: joint; 2: outer cylinder; 3: pressure cylinder; 4: seal ring I; 5: spring I; 6: jaw sleeve; 7: seal ring II; 8: seal ring III; 9: thrust ball bearing; 10: sliding cylinder; 11: spring II; 12: seal ring IV; 13: end cap; 14: blade; 15: secondary crushing connecting rod; 16: blade connecting base; 17: nozzle I; 18: nozzle II; 201: seal ring groove I, 202: step I; 203: jaw; 204: seal ring groove II; 205: nozzle hole I, 206: seal ring groove III; 207: rectangular through hole, 208: step II; 209: chute; 301: necked step opening; 302: step III; 303: recess; 304: section; 305: helical surface I; 601: helical surface II; 602: section; 603: gap; 604: step IV; 1301: seal ring IV; 1302: step V; 1303: nozzle hole II; 1401: through hole I; 1402: cutting tooth; 1403: flat tooth; 1404: through hole II; 1405: special-shaped groove; 1406: flat tooth; 1407: ball tooth; 1501: through hole III; 1502: crushing tooth; 1503: notch; 1504: through hole IV; 1505: groove I, 1601: bolt through hole; 1602: through hole V; 1603: groove II.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(14) The present invention is further described below with reference to the accompanying drawings, and the protection scope of the present invention is not limited to the following description.

(15) As shown in FIG. 1 to FIG. 12, a combined crushing super-variable-diameter drill bit for natural gas hydrate exploitation includes: a joint 1, an outer cylinder 2 connected to the joint 1 by thread, a nozzle I 17 mounted in the outer cylinder 2, a mechanical locking mechanism, a blade telescoping mechanism, an end cap 13 connected to the outer cylinder 2 by thread, a seal ring IV 12 mounted to the end cap 13, and a nozzle II 18 mounted in the end cap 13 by threaded connection, wherein an upper portion of the outer cylinder 2 is provided with a seal ring groove I 201, a middle-upper portion of the outer cylinder 2 is provided with a step I 202, raised jaws 203 in three positions are circumferentially distributed in a middle portion of the outer cylinder 2, a seal ring groove II 204 is disposed below the jaws 203, nozzle holes I 205 in three positions are circumferentially disposed below the seal ring groove II 204, there are 4 holes in each position, a seal ring groove III 206 is disposed below the nozzle holes I 205, rectangular through holes 207 in three positions are circumferentially disposed in a middle-lower portion of the outer cylinder 2, a lower portion of the rectangular through holes 207 is provided with a chute 209, and a step II 208 is disposed in an inner lower portion of the outer cylinder 2;

(16) the mechanical locking mechanism includes a pressure cylinder 3, a seal ring I 4, a spring I 5, a jaw sleeve 6, a seal ring II 7, and a seal ring III 8, an upper end of the pressure cylinder 3 is limited by a lower end face of the upper joint 1, the seal ring I 4 is disposed between the pressure cylinder 3 and the outer cylinder 2, the spring I 5 is located in the outer cylinder 2 and two ends thereof are respectively connected between a step of the pressure cylinder 3 and the step inside the outer cylinder 2, the pressure cylinder 3 is in contact with the jaw sleeve 6, and the seal ring II 7 and the seal ring III 8 are disposed between the jaw sleeve 6 and the outer cylinder 2;

(17) the blade telescoping mechanism includes a thrust ball bearing 9, a sliding cylinder 10, a spring II 11, a blade 14, a secondary crushing connecting rod 15, and a blade connecting base 16, the thrust ball bearing 9 is mounted between the jaw sleeve 6 and the sliding cylinder 10, the sliding cylinder 10 is in clearance fit with the jaw sleeve 6, the spring II 11 is connected between the sliding cylinder 10 and the step in the outer cylinder 2, the blade connecting base 16 is connected to the sliding cylinder 10 by bolt, two ends of the secondary crushing connecting rod 15 are respectively connected to the blade 14 and the outer cylinder 2 by bolt, the blade 14 is connected to the blade connecting base 16 by bolt, wherein an upper end of the secondary crushing connecting rod 15 is provided with a through hole III 1501, a left side of the secondary crushing connecting rod 15 is provided with two rows of raised crushing teeth 1502, two sides of the crushing teeth 1502 are symmetrically provided with two rows of notches 1503, a lower end of the secondary crushing connecting rod 15 is provided with a through hole IV 1504, and a groove I 1505 is disposed in the middle of the secondary crushing connecting rod 15, to make the secondary crushing connecting rod 15 take the shape of a fork; an upper end of the end cap 13 is provided with a seal ring groove IV 1301, the middle of the end cap 13 is provided with a step V 1302, and the end cap 13 is circumferentially provided with nozzle holes II 1303 in three positions; and the nozzle II 18 is mounted in the nozzle holes II 1303.

(18) In the mechanical locking mechanism of the present invention, a necked step opening 301 is disposed on the inside of the pressure cylinder 3, a step III 302 is disposed on the outside of the pressure cylinder 3, recesses 303 in three positions are disposed along a circumferential direction of an outer wall of the pressure cylinder 3, helical surfaces I 305 in three positions are disposed at a lower end of the pressure cylinder 3, and sections 304 in three positions are disposed on the helical surfaces I 305 in three positions; an upper end of the jaw sleeve 6 is provided with helical surfaces II 601 in six positions, sections 602 in three positions and gaps 603 in three positions are intersected on the six helical surfaces II 601, and a step IV 604 is disposed in the middle of the jaw sleeve 6; and the recesses 303 match with the jaws 203, and the helical surfaces I 305 on the pressure cylinder 3 are in contact with the helical surfaces II 601 on the jaw sleeve 6.

(19) In the blade telescoping mechanism in the present invention, the blade 14 includes a through hole I 1401, cutting teeth 1402, flat teeth 1403, a through hole II 1404, a special-shaped groove 1405, flat teeth 1406, and ball teeth 1407, the through hole I 1401 is disposed on an upper end of the blade 14, the cutting teeth 1402 are uniformly disposed along edges of the blade 14, two rows of flat teeth 1403 are disposed on an outer side of the blade 14, the through hole II 1404 is disposed in a middle portion of the blade 14, the special-shaped groove 1405 is disposed on the blade 14, the flat teeth 1406 of the blade 14 are disposed a lower outer side of the blade 14, and the ball teeth 1407 are disposed at a lower end of the blade 14; the blade connecting base 16 is provided with a bolt through hole 1601, a through hole V 1602, and a groove II 1603; the blade connecting base 16 is connected to the sliding cylinder 10 through a bolt through hole 1601 by using a bolt, the through hole I 1401 is connected to the through hole V 1602 by bolt, to make the blade 14 connected to the blade connecting base 16, the through hole II 1404 is connected to the through hole III 1501 by bolt, to make the middle portion of the blade 14 connected to the secondary crushing connecting rod 15 by bolt, and the secondary crushing connecting rod 15 is connected to the outer cylinder 2 through the through hole IV 1504 by using a bolt.

(20) The working process of the present invention is as follows:

(21) Initial state: in the left figure of FIG. 2, the pressure cylinder 3 is in the top-most position under the action of the spring 15, in which case the jaw 203 of the outer cylinder 2 is stuck on the gap 603 of the jaw sleeve 6, the blade 14 is in a closed state, the drill bit is in normal rock-crushing drilling work, and the nozzle II 18 in the front end of the drill bit ejects a high-pressure drilling fluid to assist in crushing and cleaning the drill bit.

(22) Operating state I: referring to FIG. 4, the flow rate of the drilling fluid is increased, and when the drilling fluid passes through the necked step opening 301 of the pressure cylinder 3, due to a flow channel change, the drilling fluid exerts a great pressure on the pressure cylinder 3 to cause the pressure cylinder 3 to push the jaw sleeve 6 to move downward; when the pressure cylinder 3 is at the lowest end of the stroke, the jaws 203 leave the gap 603 on the jaw sleeve 6, and the jaw sleeve 6 rotates because the helical surfaces I 305 of the pressure cylinder 3 coordinate with the helical surfaces II 601 of the jaw sleeve 6; moreover, while the jaw sleeve 6 moves downward, the thrust ball bearing 9 and the sliding cylinder 10 are driven to move downward, the sliding cylinder 10 drives the blade connecting base 16 to move downward, and the blade 14 is opened through coordination of the blade connecting base 16, the secondary crushing connecting rod 15 and the blade 14; moreover, with the downward movement of the jaw sleeve 6, the gap 603 of the jaw sleeve 6 rotates to the nozzle hole I 205, in which case the high-pressure drilling fluid is ejected from the nozzle I 17, the hydrate begins to be crushed by hydraulic force, the flow rate of the drilling fluid is reduced after a certain period of time, so that the pressure of the drilling fluid on the pressure cylinder 3 is reduced. Under the action of the spring 15 and the spring II 11, the pressure cylinder 3 and the jaw sleeve 6 begin to rebound, in which case the helical surfaces II 601 of the jaw sleeve 6 come into contact with an inclined surface of the jaws 203 and rotates, so that the jaws 203 are stuck to the sections 602 of the jaw sleeve 6, to implement a function of mechanically locking the blade 14. At this point, the blade 14 has extended out, and normal mechanical crushing and secondary mechanical crushing of the hydrate start. Besides, with the downward movement of the jaw sleeve 6, the lower end of the jaw sleeve 6 coordinates with the end cap 13 and the sealing ring IV 12 to achieve the plugging of the nozzle II 18, and the nozzle II 18 stops operating.

(23) Operating state II: if the drill bit is stuck when crushing the hydrate or when the drill bit is retracted after crushing, similar to the previous working process, the flow rate of the drilling fluid is increased, and when the drilling fluid passes through the necked step opening 301 of the pressure cylinder 3, due to a flow channel change, the drilling fluid exerts a great pressure on the pressure cylinder 3 to cause the pressure cylinder 3 to push the jaw sleeve 6 to move downward; when the pressure cylinder 3 is at the lowest end of the stroke, the jaws 203 leave the section 602 on the jaw sleeve 6, and the jaw sleeve 6 rotates because the helical surfaces I 305 of the pressure cylinder 3 coordinate with the helical surfaces II 601 of the jaw sleeve 6. The flow rate of the drilling fluid is reduced after a certain period of time, so that the pressure on the pressure cylinder 3 is reduced. Under the action of the spring I 5 and the spring II 11, the pressure cylinder 3 and the jaw sleeve 6 begin to rebound, in which case the helical surfaces II 601 of the jaw sleeve 6 come into contact with an inclined surface of the jaws 203 and rotates, so that the jaws 203 are stuck to the gaps 603 of the jaw sleeve 6, the jaw sleeve 6 and the sliding cylinder 10 continue to move upward under the action of the spring II 11, the blade 14 is retracted and mechanically locked through the blade connecting base 16; at the same time, the gaps 603 of the jaw sleeve 6 rotate away from the nozzle holes I 205, the nozzle I 17 and the blade 14 stop crushing the hydrate.

(24) The above steps are repeated when an expanding operation is required again.

(25) Finally, it should be noted that, the above embodiments are intended only to describe instead of limiting the technical solution of the present invention. Although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the patent may still be amended or equally replaced. Any modification or partial replacement without departing from the spirit and scope of the present invention shall all be covered within the scope of the claims of the present invention.