Sea double-gradient drilling riser packing device

Abstract

The invention discloses an ocean double-gradient drilling riser packing device which comprises an upper end sleeve, a continuous pipeline, a middle sleeve, an upper one-way valve, a lower one-way valve, an annular container, a gas conveying pipe, a sliding groove, a rack, an aperture, a lower end sleeve, a lower water conveying pipeline, a blade, a lifting pump, an upper branch water conveying pipeline, an upper water conveying pipeline, a reset spring, an air cylinder and an aperture rotating disc. The upper end sleeve is connected with the middle sleeve through threads, the middle sleeve is connected with the lower end sleeve through threads, the upper annular space and the lower annular space are filled with seawater, the lower water conveying pipeline is communicated with the lower annular space and an inlet of the lifting pump, and the upper water conveying pipeline is communicated with the upper annular space and an outlet of the lifting pump. The upper branch water conveying pipeline is communicated with an inlet of the annular container and the upper water conveying pipeline, the air conveying pipe is communicated with an air inlet and an air outlet of the annular container and the air cylinder, and the rack can linearly slide in the sliding groove. The lifting pump provides power, and the device can achieve separation of the upper cavity and the lower cavity of the continuous pipeline.

Description

Technical Field

[0001] The invention belongs to the field of marine dual-gradient drilling riser isolation, and in particular relates to a marine dual-gradient drilling riser isolation device. Background Art

[0002] By optimizing the wellbore pressure distribution, the dual gradient drilling technology can better match the formation pressure window and effectively solve the common narrow pressure window problem in deepwater drilling, so as to achieve the purpose of reducing costs, shortening the well construction cycle, and enhancing the safety of operations. The existing dual gradient drilling technologies mainly include: double-layer pipe drilling dual gradient technology, subsea pump lifting dual gradient technology, and dual-density dual gradient technology. Among them, the double-layer pipe drilling dual gradient system equipment structure is complex and has high technical requirements; the subsea pump lifting dual gradient drilling technology requires a subsea pump, so the economic cost is high and the technical complexity is relatively large; the dual-density dual gradient drilling technology has the advantages of simple equipment requirements, high operational flexibility, and low maintenance cost compared to the double-layer pipe dual gradient drilling technology; the dual-density dual gradient drilling technology has the advantages of no need for a subsea pump and high system reliability compared to the subsea pump lifting dual gradient technology. The dual-density dual gradient drilling technology is mainly divided into: hollow ball injection dual gradient drilling technology and low-density fluid injection drilling technology. The hollow ball injection dual gradient drilling technology has the phenomenon of slippage when the hollow ball moves in the drilling fluid, which will cause the upper annulus pressure to be too low and the lower annulus pressure to be too high, thus causing overflow or leakage, etc., and this technology has high requirements on the material and size of the hollow ball, which increases the technical difficulty and cost; the low-density fluid injection dual gradient drilling technology does not require special seabed equipment, but requires the configuration of low-density fluid. Therefore, it is very necessary to develop a dual gradient drilling isolation device that uses seawater as a low-density fluid to meet the needs of dual-density dual gradient drilling technology. Summary of the invention

[0003] The object of the present invention is to provide a marine dual-gradient drilling riser isolation device to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: comprising an upper sleeve, a continuous pipeline, a middle sleeve, an upper non-return valve, a lower non-return valve, an annular container, an air pipe, a chute, a rack, an aperture, a lower sleeve, a lower water pipe, blades, a lifting pump, an upper branch water pipe, an upper water pipe, a return spring, a cylinder, and an aperture turntable, wherein the upper sleeve and the middle sleeve are connected by threads, the middle sleeve and the lower sleeve are connected by threads, the upper annular space and the lower annular space are filled with seawater, the lower water pipe connects the lower annular space and the inlet of the lifting pump, the upper water pipe connects the upper annular space and the outlet of the lifting pump, the upper branch water pipe connects the inlet of the annular container and the upper water pipe, the air pipe connects the air inlet and outlet of the annular container and the cylinder, the rack is used to slide linearly in the chute, one end of the return spring is fixedly connected to the aperture turntable, and the other end is fixedly connected to the aperture housing.

[0005] The annular container is filled with a specified volume of seawater, and the remaining space is filled with inert gas. The annular container is fixed to the middle casing by screws, and the annular container is connected to the gas pipeline through the top interface and the side interface respectively. An upper one-way valve is arranged on the top gas pipeline, and the upper one-way valve only allows inert gas to enter the gas pipeline from the annular container. A lower one-way valve is arranged on the side gas pipeline, and the lower one-way valve only allows inert gas to enter the annular container from the gas pipeline. When not working, the upper one-way valve and the lower one-way valve are both closed to ensure that the inert gas in the annular container does not leak.

[0006] The piston rod of the cylinder is connected to the rack, and the extension and retraction of the piston rod of the cylinder drives the rack to reciprocate on the slideway, and the slideway is fixed on the middle sleeve.

[0007] The aperture is composed of an aperture rotating disk, a plurality of blades, an aperture shell, and an aperture cover. Each blade has a boss on the top and bottom surfaces, wherein the boss on the bottom surface is inserted into the hole on the aperture rotating disk to form a hinge, and the boss on the top surface is inserted into the groove on the aperture cover. According to its structural characteristics, when the aperture rotating disk rotates, all the blades will rotate at the same angle, thereby obtaining an annular circle. The diameter of the annular circle can be adjusted by adjusting the rotation amplitude of the aperture rotating disk. There are incomplete gears on the aperture rotating disk. Through the mutual meshing of the gear rack, the reciprocating motion of the rack causes the aperture rotating disk to rotate. The aperture shell is fixed to the lower end sleeve by screws. The resistor and the protective resistor are precision wound resistors, whose resistance values ​​are less affected by temperature and pressure. The resistance value of the protective resistor should be smaller than the resistance value of the resistor.

[0008] The return spring is stretched when the aperture rotating disk is working. When the aperture rotating disk stops working, the return spring pulls the aperture rotating disk to return to its original position. When the aperture rotating disk is not working, the return spring is in the original length state.

[0009] It can be seen from the above technical solution that compared with the existing dual gradient drilling technology, the present invention has the following beneficial effects:

[0010] (1) The present invention controls the annulus diameter through blades and return springs to achieve continuous pipeline separation and connection, and has the characteristics of convenient control and good segmentation effect; (2) The present invention uses the chemical and physical properties of inert gas to drive the movement of the cylinder, and has the characteristics of good environmental performance and high safety performance; (3) The present invention uses gear rack meshing to control the movement of the blades, and has the characteristics of long service life. (4) The present invention uses seawater as a low-density fluid and does not need to configure low-density fluid. It is simple to operate and easy to use. (5) The present invention belongs to a sealing device, which does not require a seabed pump to lift the seabed pump device in the dual-gradient drilling technology, and does not require a double-layer pipe in the double-layer pipe drilling dual-gradient technology. It has the characteristics of simple device structure and good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Attached Figure 1 It is a schematic diagram of the structure of the present invention;

[0012] Attached Figure 2 is a cross-sectional view of an annular container;

[0013] Attached Figure 3 It is a schematic diagram of the aperture blades from the starting state to the working state;

[0014] Attached Figure 4 It is a schematic diagram of the blades mounted on the aperture disc;

[0015] Attached Figure 5 It is a schematic diagram of the aperture cover;

[0016] Attached Figure 6 is a three-dimensional schematic diagram of the blade;

[0017] Attached Figure 7 It is a partial enlarged view of the return spring;

[0018] Attached Figure 8 It is a partial enlarged view of the chute;

[0019] In the figure: including 1-upper end casing, 2-continuous pipeline, 3-upper annular space, 4-middle casing, 5-upper one-way valve, 6-lower one-way valve, 7-annular container, 8-air pipeline, 9-chute, 10-rack, 11-aperture, 12-lower annular space, 13-lower end casing, 14-lower water pipeline, 15-blade, 16-lifting pump, 17-upper branch water pipeline, 18-upper water pipeline, 19-reset spring, 20-cylinder, 21-aperture turntable. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0021] The present invention provides Figure 1-8 The marine dual-gradient drilling riser isolation device shown in the figure comprises an upper casing 1, a continuous pipeline 2, a middle casing 4, an upper one-way valve 5, a lower one-way valve 6, an annular container 7, an air pipeline 8, a chute 9, a rack 10, an aperture 11, a lower casing 13, a lower water pipeline 14, a blade 15, a lifting pump 16, an upper branch water pipeline 17, an upper water pipeline 18, a reset spring 19, a cylinder 20, and an aperture turntable 21. The upper casing 1 and the middle casing 4 are connected by threads, and the middle casing 4 and the lower casing 13 are connected by threads. Then, the upper annular space 3 and the lower annular space 12 are filled with seawater, the lower water pipeline 14 is connected to the lower annular space 12 and the inlet of the lifting pump 16, the upper water pipeline 18 is connected to the upper annular space 3 and the outlet of the lifting pump 16, the upper branch water pipeline 17 is connected to the inlet of the annular container 7 and the upper water pipeline 18, the air pipe 8 is connected to the air inlet and outlet of the annular container 7 and the cylinder 20, the rack 10 is used to slide linearly in the slide groove 9, and one end of the return spring 19 is fixedly connected to the aperture turntable 21, and the other end is fixedly connected to the aperture housing.

[0022] Specifically, the annular container 7 is filled with a specified volume of seawater, and the remaining space is filled with inert gas. The annular container 7 is fixed to the middle sleeve 4 by screws. The annular container 7 is connected to the gas pipe 8 through the top interface and the side interface respectively. An upper one-way valve 5 is provided on the top gas pipeline. The upper one-way valve 5 only allows inert gas to enter the gas pipe 8 from the annular container 7. A lower one-way valve 6 is provided on the side gas pipeline. The lower one-way valve 6 only allows inert gas to enter the annular container 7 from the gas pipe 8. When not in operation, the upper one-way valve 5 and the lower one-way valve 6 are both closed to ensure that the inert gas in the annular container 7 does not leak.

[0023] Specifically, the piston rod of the cylinder 20 is connected to the rack 10 , and the extension and retraction of the piston rod of the cylinder 20 drives the rack 10 to reciprocate on the slide groove 9 , and the slide groove 9 is fixed on the middle sleeve 4 .

[0024] Specifically, the aperture 11 is composed of an aperture turntable 21, a plurality of blades 15, an aperture shell, and an aperture cover. Each blade 15 has a boss on the top and bottom surfaces respectively, wherein the boss on the bottom surface is inserted into the hole on the aperture turntable 21 to form a hinge, and the boss on the top surface is inserted into the groove on the aperture cover; when the aperture turntable 21 rotates, all the blades 15 will rotate by the same angle, thereby obtaining an annular circle, and the diameter of the annular circle can be adjusted by adjusting the rotation amplitude of the aperture turntable 21; there are incomplete gears on the aperture turntable 21, and through the mutual engagement of the gear rack, the reciprocating motion of the rack 10 causes the aperture turntable 21 to rotate, and the aperture shell is fixed to the lower end sleeve 13 by screws.

[0025] Specifically, the return spring 19 is stretched when the aperture disk 21 is working. When the aperture disk 21 stops working, the return spring 19 pulls the aperture disk 21 back to its original position. When the aperture disk 21 is not working, the return spring 19 is in the original length state.

[0026] Specifically, the specific working steps include: starting the lifting pump 16, the seawater in the lower annular space 12 enters the lifting pump 16 through the lower water delivery pipe 14, the seawater pressurized by the lifting pump 16 enters the upper annular space 3 and the annular container 7 through the upper water delivery pipe 18 and the upper branch water delivery pipe 17 respectively, when the seawater enters the annular container 7, the inert gas in the annular container 7 enters the cylinder 20 through the upper one-way valve 5 to push the piston rod to move, the piston rod extends outward to drive the rack 10 to move outward, the outward movement of the rack 10 drives the aperture turntable 21 to rotate counterclockwise, the counterclockwise rotation of the aperture turntable 21 drives all the blades 15 to rotate, all the blades 15 rotate to form an annular circle, and the diameter of the annular circle gradually decreases until the diameter of the annular circle formed after the blades 15 rotate is equal to the outer diameter of the continuous pipe 2, thereby realizing the separation of the upper annular space 3 and the lower annular space 12, at this time the reset spring 19 is in a stretched state;

[0027] After the work is completed, the lifting pump 16 is turned off, and the seawater in the upper branch water pipe 17 no longer enters the annular container 7. At this time, under the stretching action of the return spring 19, the aperture turntable 21 rotates clockwise, all the blades 15 rotate, and the diameter of the annular circle becomes larger. At the same time, the aperture turntable 21 rotates clockwise to drive the rack 10 to move inward. Under the action of the piston rod, the piston in the cylinder 20 also moves inward, and the inert gas returns to the annular container 7 from the lower one-way valve 6. Part of the seawater in the annular container 7 is discharged from the upper branch water pipe 17 to the upper annular space 3.

[0028] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A marine dual-gradient drilling riser isolation device, characterized in that: The invention comprises an upper sleeve (1), a continuous pipeline (2), a middle sleeve (4), an upper non-return valve (5), a lower non-return valve (6), an annular container (7), an air pipeline (8), a chute (9), a rack (10), an aperture (11), a lower sleeve (13), a lower water pipeline (14), a blade (15), a lifting pump (16), an upper branch water pipeline (17), an upper water pipeline (18), a return spring (19), a cylinder (20), and an aperture rotating disk (21). The upper sleeve (1) and the middle sleeve (4) are connected by threads, and the middle sleeve (4) and the lower sleeve (13) are connected by threads. The interior of the upper sleeve (1) and the exterior of the continuous pipeline (2) form an annular space, and the blade (15) divides the entire annular space into an upper annular space (3) and a lower annular space (4). The invention relates to a pump (15) and a reciprocating piston rod (12), wherein the upper annular space (3) is located at the upper end of the blade (15), and the lower annular space (12) is located at the lower end of the blade (15). The upper annular space (3) and the lower annular space (12) are filled with seawater. The lower water delivery pipeline (14) is connected to the lower annular space (12) and the inlet of the lifting pump (16). The upper water delivery pipeline (18) is connected to the outlet of the upper annular space (3) and the lifting pump (16). The upper branch water delivery pipeline (17) is connected to the inlet of the annular container (7) and the upper water delivery pipeline (18). The air delivery pipe (8) is connected to the air inlet and outlet of the annular container (7) and the cylinder (20). The rack (10) is used to slide linearly in the slide groove (9). One end of the return spring (19) is fixedly connected to the aperture rotating disk (21) and the other end is fixedly connected to the aperture housing.

2. The marine dual-gradient drilling riser isolation device according to claim 1, characterized in that: The annular container (7) contains a specified volume of seawater, and the remaining space is filled with inert gas. The annular container (7) is fixed to the middle sleeve (4) by screws. The annular container (7) is connected in parallel to the upper end of the gas pipeline (8) through the top interface and the side interface. An upper one-way valve (5) is arranged on the top gas pipeline. The upper one-way valve (5) only allows the inert gas to enter the gas pipeline (8) from the annular container (7). The lower end of the gas pipeline (8) is connected to the cylinder (20). A lower one-way valve (6) is arranged on the side gas pipeline. The lower one-way valve (6) only allows the inert gas to enter the annular container (7) from the gas pipeline (8). When not in operation, the upper one-way valve (5) and the lower one-way valve (6) are both closed to ensure that the inert gas in the annular container (7) does not leak.

3. The marine dual-gradient drilling riser isolation device according to claim 1, characterized in that: The piston rod of the cylinder (20) is connected to the rack (10), and the extension and retraction of the piston rod of the cylinder (20) drives the rack (10) to reciprocate on the slide groove (9), and the slide groove (9) is fixed on the middle sleeve (4).

4. The marine dual-gradient drilling riser isolation device according to claim 1, characterized in that: The aperture (11) is composed of an aperture rotating disk (21), a plurality of blades (15), an aperture shell, and an aperture cover. Each blade (15) has a boss on the top and bottom surfaces respectively, wherein the boss on the bottom surface is inserted into a hole on the aperture rotating disk (21) to form a hinge, and the boss on the top surface is inserted into a groove on the aperture cover. When the aperture rotating disk (21) rotates, all the blades (15) rotate at the same angle, thereby obtaining an annular circle. The diameter of the annular circle can be adjusted by adjusting the rotation amplitude of the aperture rotating disk (21). An incomplete gear is provided on the aperture rotating disk (21). Through the mutual meshing of the gear rack, the reciprocating motion of the rack (10) causes the aperture rotating disk (21) to rotate. The aperture shell is fixed to the lower end sleeve (13) by screws.

5. The marine dual-gradient drilling riser isolation device according to claim 1, characterized in that: The return spring (19) is stretched when the aperture rotating disk (21) is working. When the aperture rotating disk (21) stops working, the return spring (19) pulls the aperture rotating disk (21) to return to its original position. When the aperture rotating disk (21) is not working, the return spring (19) is in an original length state.

6. The marine dual-gradient drilling riser isolation device according to claim 1, characterized in that: The specific work steps include: The lifting pump (16) is started, and the seawater in the lower annular space (12) enters the lifting pump (16) through the lower water delivery pipe (14). The seawater pressurized by the lifting pump (16) enters the upper annular space (3) and the annular container (7) through the upper water delivery pipe (18) and the upper branch water delivery pipe (17). When the seawater enters the annular container (7), the inert gas in the annular container (7) enters the cylinder (20) through the upper non-return valve (5) to push the piston rod to move, and the piston rod extends outward to drive the rack (10) moves outward, the rack (10) moves outward to drive the aperture rotating disk (21) to rotate counterclockwise, the aperture rotating disk (21) rotates counterclockwise to drive all the blades (15) to rotate, all the blades (15) rotate to form an annular circle, and the diameter of the annular circle gradually decreases until the diameter of the annular circle formed after the blades (15) rotate is equal to the outer diameter of the continuous pipe (2), thereby realizing the separation of the upper annular space (3) and the lower annular space (12), at which time the return spring (19) is in a stretched state; After the work is completed, the lifting pump (16) is turned off, and the seawater in the upper branch water delivery pipe (17) no longer enters the annular container (7). At this time, under the tensile action of the return spring (19), the aperture turntable (21) rotates clockwise, all the blades (15) rotate, and the diameter of the annular space becomes larger. At the same time, the aperture turntable (21) rotates clockwise to drive the rack (10) to move inward. Under the action of the piston rod, the piston in the cylinder (20) also moves inward, and the inert gas returns to the annular container (7) from the lower one-way valve (6). A part of the seawater in the annular container (7) is discharged from the upper branch water delivery pipe (17) to the upper annular space (3).

Images