Negative pressure jet flow sand washing and bailing device and method

Abstract

The invention provides a negative pressure jet flow sand washing and bailing device and method. The negative pressure jet flow sand washing and bailing device mainly comprises a drilling pump, a drilling rod, a packer, a double-wall drilling rod, a sand bailing cylinder body, a negative pressure generator body and a sand disturbing head body; a drill rod is connected with a double-wall drill rod inner pipe through threads, the double-wall drill rod and a shaft annulus are sealed and separated through a packer, power liquid enters a double-wall drill rod annulus channel through the packer, the double-wall drill rod inner pipe is a reverse liquid outlet channel, and flowing liquid enters a sand disturbing head body high-pressure cavity through a sand bailing cylinder body annulus channel and a negative pressure generator body annulus channel. When the fluid passes through the high-pressure cavity of the sand washing head body, most of the fluid is jetted upwards at a high speed through the jet flow nozzle, a vacuum low-pressure area is formed, and the fluid flows out of a wellhead through the inner pipe of the double-wall drill rod and the drill rod. The sand bailing device is simple in structural principle and high in sand bailing efficiency, the pressure of a bottom hole flow field during sand bailing operation can be reduced, and leakage and pollution to a production layer during sand bailing operation are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of oil field well repairing, and in particular to a negative pressure jet sand flushing and bailing device and method. Background Art

[0002] Sand production is unavoidable during the development of oil and gas fields. Although many anti-sand measures are taken during the exploitation process, oil and gas wells still have sand production problems to varying degrees during the actual production process. Sand production in oil wells will erode the oil pipes and ground equipment, causing damage to them, bringing great difficulties to the implementation and maintenance of the process. More importantly, sand production will increase fluid flow resistance, affect the recovery rate of oil and gas reservoirs, and reduce the output of oil and gas wells. Therefore, oil and gas well sand cleaning operations are necessary.

[0003] Hydraulic sand flushing and mechanical sand bailing are common methods for recovering and maintaining the production of sand-producing wells. Compared with mechanical sand bailing, hydraulic sand flushing has the advantages of relative stability, thorough bottom hole cleaning, strong continuity, and large sand flushing volume. However, for the sand flushing of leaking wells in low-pressure and leaky reservoirs, conventional hydraulic sand flushing technology is difficult to successfully apply. On the one hand, it is difficult to establish circulation in low-pressure leaking wells with conventional hydraulic sand flushing, and when the power fluid impacts the sand bed at the bottom of the well, the bottom hole pressure is often greater than the formation pressure, causing a large amount of sand mixing fluid to leak into the oil-producing layer, polluting the formation, and easily further reducing the production of the oil well; on the other hand, because the axis of the sand flushing operation string does not coincide with the axis of the wellbore, the sand mixing fluid flows in the eccentric annulus, and the bottom of the well is prone to sand accumulation again, resulting in sand jam.

[0004] At present, the sand bailing method for low-pressure wells prone to leakage is the new GS negative pressure sand bailing process. The annulus is equipped with a complete blowout preventer and the drill string is equipped with a special sand bailing check valve. During the sand bailing process, the square drill rod is equipped with upper and lower cocks, and the bottom of the well is maintained at a slightly positive pressure. The bottom of the well pressure is slightly greater than the formation pressure, and the wellbore pressure fluctuation is controllable. The gas distributor and the downhole safety valve are combined into one, which has the function of killing the well in the whole wellbore. The sand bailing operation is closed and there is no environmental pollution. The existing equipment can shorten the time of connecting a single root by more than half.

[0005] Although the above method is feasible, the negative pressure suction at the bottom of the well may be insufficient, and components such as special sand bailing check valves, special air distributors and downhole safety valves need to be manufactured separately, which is costly. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the present invention provides a negative pressure jet sand bailing device and method, the purpose of which is to solve the problems that the negative pressure suction may be insufficient, and that components such as special sand bailing check valves, special air distributors and downhole safety valves need to be manufactured separately, resulting in high costs.

[0007] In order to achieve the above-mentioned invention object, the technical scheme adopted by the present invention is: a negative pressure jet sand bailing device and method, including a double-wall drill pipe, a sand bailing tube body, a jet pump body, and a sand disturbing joint; the upper end of the double-wall drill pipe is provided with a packer, and the upper end of the inner wall of the double-wall drill pipe is connected to the lower end of the drill pipe; the upper end of the sand bailing tube body is connected to the lower end of the double-wall drill pipe, and the sand bailing tube body is provided with a sand bailing tube and a vortex port; the upper end of the jet pump body is connected to the lower end of the sand bailing tube body, and the jet pump body is provided with a jet pump annular hole, a suction port, a diffuser, a throat, a negative pressure chamber, and a jet nozzle; the upper end of the sand disturbing joint is connected to the lower end of the jet pump body, and the sand disturbing joint is provided with a high-pressure chamber, a sand disturbing vortex port, and a sand disturbing nozzle.

[0008] Furthermore, the double-wall drill pipe, the sand bailing tube body, and the jet pump body are connected by threads, the double-wall drill pipe annulus is connected with the sand bailing tube annulus, the jet pump annulus, and the high-pressure chamber, and the double-wall drill pipe inner tube is connected with the sand bailing tube and the diffusion tube.

[0009] Furthermore, the diffuser and the jet nozzle are of conical structure, the throat is a cylindrical channel, and the suction port is connected to the negative pressure chamber.

[0010] Furthermore, the sand bailing tube body is provided with two swirl ports, and the swirl ports are centrally symmetrical with the axis of the sand bailing tube body.

[0011] Furthermore, the sand-disturbing nozzle is parallel to the axis of the jet pump body, and the sand-disturbing nozzle is provided with two sand-disturbing swirl ports, which are centrally symmetrical with the axis.

[0012] Furthermore, the double-wall drill pipe, the sand bailing tube body, the jet pump body, and the sand disturbing joint have the same outer diameters and are connected in sequence through threads.

[0013] Furthermore, it includes a well repair pump, a winch, a traveling block, a throttle valve, a separator, and a vibrating screen installed on the ground, the well repair pump is connected to the wellhead device, a turntable is installed on the traveling block, the winch and the traveling block are connected by a wire rope, and the throttle valve, separator, and vibrating screen are connected by a return pipeline.

[0014] Furthermore, the sand scouring method comprises the following steps:

[0015] Step 1: Connect the sand disturbing joint, the jet pump body, the sand bailing tube body, the double-wall drill pipe, and the drill pipe in sequence, and lower them into the well where sand bailing is required, and lower the packer into the upper end of the double-wall drill pipe. The fluid is raised to high pressure by the well repair pump, and enters the annulus between the drill pipe and the casing through the wellhead device. When flowing through the packer, the fluid enters the annulus of the double-wall drill pipe, and flows into the annulus of the sand bailing tube, the annulus of the jet pump, and the high-pressure chamber;

[0016] Step 2: The high-pressure fluid in the high-pressure chamber flows in two directions, most of which flows through the jet nozzle. When flowing through the jet nozzle, the fluid forms a high-speed jet due to the reduction of the flow cross-sectional area, and forms a local vacuum low-pressure area in the negative pressure chamber; while a small part of the fluid flows through the tangential sand-disturbing swirl port and the sand-disturbing nozzle to form a high-speed rotating jet, which impacts and disturbs the sand bed at the bottom of the well. The sand-mixing liquid at the bottom of the well is sucked into the negative pressure suction port of the jet pump body under the action of the vacuum suction force;

[0017] Step 3: The sand mixing liquid and the high-speed fluid ejected from the jet nozzle are initially mixed in the negative pressure chamber, and are further mixed when flowing through the throat and diffuser; the mixed fluid flows through the diffuser with a continuously expanding cross-sectional diameter, and the kinetic energy is converted into pressure energy, and enters the vortex port of the sand bailing tube body. The flow direction of the sand mixing liquid changes from axial to tangential, and it rotates in the annular hole of the sand bailing tube. Under the action of centrifugal force and gravity, the sand particles settle into the sand bailing tube, and the fluid flows into the inner tube of the double-wall drill pipe and the double-wall drill pipe and returns to the ground. After returning to the ground, it is processed by the return pipeline, throttle valve, separator, and vibrating screen to complete the entire negative pressure jet sand bailing process.

[0018] The beneficial effects of the present invention are:

[0019] The invention discloses a negative pressure jet sand flushing and bailing device and method. The invention utilizes a ground well repairing pump to pump high pressure fluid into the annulus between a drill pipe and a wellbore. When passing through a packer, the fluid enters the annulus of a double-wall drill pipe, and then passes through the annulus of a sand bailing tube and the annulus of a jet pump. When entering a high pressure chamber, most of the fluid flows through a negative pressure jet nozzle and is sprayed upward at high speed to form a vacuum low pressure zone. Another small part of the fluid flows through a sand disturbing vortex port and a sand disturbing nozzle to impact and disturb a sand bed at the bottom of the well. The sand mixing liquid at the bottom of the well flows into a throat pipe under the action of negative pressure suction, and after being mixed with the fluid, the sand particles are deposited in the sand bailing tube under the action of vortex centrifugal force and gravity at the vortex port of the sand bailing tube, and the fluid returns to the ground through the drill pipe. The sand flushing and bailing process has both auxiliary disturbance of sand particles and suction effect, and the sand flushing and bailing efficiency is high.

[0020] The negative pressure jet sand flushing and bailing device and method of the present invention selects a negative pressure jet continuous sand flushing and bailing device with reasonable parameter design for different low-pressure leakage reservoirs, which can reduce the pressure of the bottom flow field during sand flushing and bailing, reduce leakage during sand flushing and bailing operations and pollution to the production layer, and can effectively solve various low-pressure leakage problems.

[0021] The invention discloses a negative pressure jet sand flushing and bailing device and method. The sand flushing and bailing circulation of the invention is basically inside the drill pipe, double-wall drill pipe, sand bailing tube body and jet pump body, which solves the problems that it is difficult to establish circulation in the traditional sand flushing process and the sand flushing fluid is easy to leak. It provides a new idea and solution for the sand flushing and bailing operation of low-pressure wells prone to leakage.

[0022] The negative pressure jet sand scooping device and method of the present invention have the advantages of simple structural principle, high process reliability, strong practicability and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of a negative pressure jet sand scooping device and method;

[0024] Figure 2 A schematic diagram of a double-wall drill pipe structure of a negative pressure jet sand bailing device and method;

[0025] Figure 3 A schematic diagram of a sand bailing tube body of a negative pressure jet sand bailing device and method;

[0026] Figure 4 A schematic diagram of a sand flushing pump structure of a negative pressure jet sand flushing and bailing device and method;

[0027] Figure 5 It is a schematic diagram of the structure of a sand disturbing joint of a negative pressure jet sand scooping device and method;

[0028] Figure 6 It is a schematic diagram of the three-dimensional model structure of a negative pressure jet sand scooping device and method;

[0029] Figure 7 The present invention is a schematic diagram of the cutaway structure of a three-dimensional model of a negative pressure jet sand scooping device and method.

[0030] Reference table of reference numerals:

[0031] 1. Well repair pump; 2. Winch; 3. Wire rope; 4. Traveling block; 5. Return pipeline; 6. Rotary table; 7. Throttle valve; 8. Separator; 9. Vibrating screen; 10. Drill pipe; 11. Wellhead device; 12. Casing; 13. Packer; 14. Double-wall drill pipe; 15. Sand bailing tube body; 16. Jet pump body; 17. Sand disturbance joint; 18. Sand bed; 19. Double-wall drill pipe outer wall; 20. Double-wall drill pipe inner wall; 21. Double-wall drill pipe inner tube; 22. Double-wall drill pipe annular hole; 23. Sand bailing tube; 24. Swirl port; 25. Sand bailing tube annular hole; 26. Jet pump annular hole; 27. Suction port; 28. Diffuser; 29. ​​Throat; 30. Negative pressure chamber; 31. Jet nozzle; 32. High pressure chamber; 33. Sand disturbance swirl port; 34. Sand disturbance nozzle. DETAILED DESCRIPTION

[0032] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings, wherein the same components are represented by the same reference numerals.

[0033] It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to directions in the drawings, and the words "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively.

[0034] In order to make the contents of the present invention more clearly understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0035] like Figures 1 to 7 As shown, a negative pressure jet sand bailing device and method comprises a double-wall drill pipe 14, a sand bailing tube body 15, a jet pump body 16, and a sand disturbing joint 17; the upper end of the double-wall drill pipe 14 is provided with a packer 13, and the upper end of the inner wall 20 of the double-wall drill pipe is connected to the lower end of the drill pipe 10; the upper end of the sand bailing tube body 15 is connected to the lower end of the double-wall drill pipe 14, and the sand bailing tube body 15 is provided with a sand bailing tube 23 and a swirl port 24; the upper end of the jet pump body 16 is connected to the lower end of the sand bailing tube body 15, and the jet pump body 16 is provided with a jet pump annular hole 26, a suction port 27, a diffuser 28, a throat 29, a negative pressure chamber 30, and a jet nozzle 31; the upper end of the sand disturbing joint 17 is connected to the lower end of the jet pump body 16, and the sand disturbing joint 17 is provided with a high pressure chamber 32, a sand disturbing swirl port 33, and a sand disturbing nozzle 34.

[0036] The double-wall drill pipe 14 , the sand bailing tube body 15 , and the jet pump body 16 are connected by threads, the double-wall drill pipe annulus 22 is connected with the sand bailing tube annulus 25 , the jet pump annulus 26 , and the high-pressure chamber 32 , and the double-wall drill pipe inner tube 21 is connected with the sand bailing tube 23 and the diffuser 28 .

[0037] The diffuser 28 and the jet nozzle 31 are of conical structures, the throat 29 is a cylindrical channel, and the suction port 27 is connected to the negative pressure chamber 30 .

[0038] The sand bailing tube body 15 is provided with two swirl ports 24 , and the swirl ports 24 are centrally symmetrical with the axis of the sand bailing tube body 15 .

[0039] The sand-disturbing nozzle 34 is parallel to the axis of the jet pump body 16 , and is provided with two sand-disturbing swirl ports 33 , which are centrally symmetrical with the axis.

[0040] The double-wall drill pipe 14, the sand bailing tube body 15, the jet pump body 16, and the sand disturbing joint 17 have the same outer diameters and are connected in sequence through threads.

[0041] The well repairing device comprises a well repairing pump 1, a winch 2, a traveling block 4, a throttle valve 7, a separator 8 and a vibrating screen 9 installed on the ground. The well repairing pump 1 is connected to a wellhead device 11. A turntable 6 is installed on the traveling block 4. The winch 2 and the traveling block 4 are connected by a wire rope 3. The throttle valve 7, the separator 8 and the vibrating screen 9 are connected by a return pipeline 5.

[0042] The sand scouring method in the present invention comprises the following steps:

[0043] In actual use, first, the sand disturbing joint 17, the jet pump body 16, the sand bailing tube body 15, the double-wall drill pipe 14, and the drill pipe 10 are connected in sequence, and lowered into the well where sand bailing is required, and the packer 13 is lowered into the upper end of the double-wall drill pipe 14. The fluid is raised to high pressure by the well repair pump 1, and enters the annular hole between the drill pipe 10 and the casing 12 through the wellhead device 11. When flowing through the packer 13, the fluid enters the annular hole 22 of the double-wall drill pipe, and flows into the annular hole 25 of the sand bailing tube, the annular hole 26 of the jet pump, and the high-pressure chamber 32;

[0044] Secondly, the high-pressure fluid in the high-pressure chamber 32 flows in two directions, most of which flows through the jet nozzle 31. When flowing through the jet nozzle 31, the fluid forms a high-speed jet due to the reduction of the flow cross-sectional area, and forms a local vacuum low-pressure area in the negative pressure chamber 30; while a small part of the fluid flows through the tangential sand-disturbing swirl port 33 and the sand-disturbing nozzle 34 to form a high-speed rotating jet, which impacts and disturbs the sand bed 18 at the bottom of the well, and the sand-mixing liquid at the bottom of the well is sucked into the negative pressure suction port 27 of the jet pump body 16 under the action of the vacuum suction force;

[0045] Finally, the sand mixing liquid and the high-speed fluid ejected from the jet nozzle 31 are preliminarily mixed in the negative pressure chamber 30, and are further mixed when flowing through the throat 29 and the diffuser 28; the mixed fluid flows through the diffuser 28 with a continuously expanding cross-sectional diameter, and the kinetic energy is converted into pressure energy, and enters the vortex port 24 of the sand bailing tube body 15, and the flow direction of the sand mixing liquid changes from axial to tangential, and rotates in the annular hole of the sand bailing tube 23. Under the action of centrifugal force and gravity, the sand particles settle into the sand bailing tube 23, and the fluid flows into the double-wall drill pipe inner tube 21 and the double-wall drill pipe 14 and returns to the ground. After returning to the ground, it is processed by the return pipeline 5, the throttle valve 7, the separator 8, and the vibrating screen 9, completing the entire negative pressure jet sand bailing process.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A negative pressure jet sand scouring device and method, characterized in that: The invention comprises a double-wall drill pipe (14), a sand bailing tube body (15), a jet pump body (16), and a sand disturbing joint (17); the upper end of the double-wall drill pipe (14) is provided with a packer (13); the upper end of the inner wall (20) of the double-wall drill pipe is connected to the lower end of the drill pipe (10); the upper end of the sand bailing tube body (15) is connected to the lower end of the double-wall drill pipe (14); the sand bailing tube body (15) is provided with a sand bailing tube (23) and a vortex port (24); the jet pump body The upper end of the jet pump body (16) is connected to the lower end of the sand bailing tube body (15), and the jet pump body (16) is provided with a jet pump annular hole (26), a suction port (27), a diffusion pipe (28), a throat pipe (29), a negative pressure chamber (30), and a jet nozzle (31); the upper end of the sand disturbing joint (17) is communicated with the lower end of the jet pump body (16), and the sand disturbing joint (17) is provided with a high pressure chamber (32), a sand disturbing swirl port (33), and a sand disturbing nozzle (34).

2. A negative pressure jet sand scouring device and method according to claim 1, characterized in that: The double-wall drill pipe (14), the sand bailing tube body (15), and the jet pump body (16) are connected by threads; the double-wall drill pipe annular hole (22) is connected with the sand bailing tube annular hole (25), the jet pump annular hole (26), and the high-pressure chamber (32); and the double-wall drill pipe inner tube (21) is connected with the sand bailing tube (23) and the diffusion tube (28).

3. A negative pressure jet sand scouring device and method according to claim 1, characterized in that: The diffuser (28) and the jet nozzle (31) are of conical structure, the throat (29) is a cylindrical channel, and the suction port (27) is in communication with the negative pressure chamber (30).

4. A negative pressure jet sand scouring device and method according to claim 1, characterized in that: The sand bailing tube body (15) is provided with two swirl ports (24), and the swirl ports (24) are centrally symmetrical with the axis of the sand bailing tube body (15).

5. A negative pressure jet sand scouring device and method according to claim 1, characterized in that: The sand-disturbing nozzle (34) is parallel to the axis of the jet pump body (16), and the sand-disturbing nozzle (34) is provided with two sand-disturbing swirl ports (33), and the sand-disturbing swirl ports (33) are centrally symmetrical with the axis.

6. A negative pressure jet sand scouring device and method according to claim 1, characterized in that: The double-wall drill pipe (14), the sand bailing tube body (15), the jet pump body (16) and the sand disturbing joint (17) have the same outer diameters and are connected in sequence through threads.

7. A negative pressure jet sand scouring device and method according to claim 1, characterized in that: The invention comprises a well repair pump (1), a winch (2), a traveling carriage (4), a throttle valve (7), a separator (8) and a vibrating screen (9) installed on the ground. The well repair pump (1) is connected to a wellhead device (11). A turntable (6) is installed on the traveling carriage (4). The winch (2) and the traveling carriage (4) are connected by a steel wire rope (3). The throttle valve (7), the separator (8) and the vibrating screen (9) are connected by a return pipeline (5).

8. A negative pressure jet sand scouring device and method according to any one of claims 1 to 7, characterized in that: The sand scouring method comprises the following steps: Step 1: sequentially connect the sand disturbing joint (17), the jet pump body (16), the sand bailing tube body (15), the double-wall drill pipe (14), and the drill pipe (10), and lower them into the well where sand bailing is required, and lower the packer (13) into the upper end of the double-wall drill pipe (14); the fluid is raised to high pressure by the well repair pump (1), and enters the annular hole between the drill pipe (10) and the casing (12) through the wellhead device (11); when flowing through the packer (13), the fluid enters the annular hole (22) of the double-wall drill pipe, and flows into the annular hole (25) of the sand bailing tube, the annular hole (26) of the jet pump, and the high-pressure chamber (32); Step 2: The high-pressure fluid in the high-pressure chamber (32) flows in two directions, wherein most of the fluid flows through the jet nozzle (31). When flowing through the jet nozzle (31), the fluid forms a high-speed jet due to the reduction of the flow cross-sectional area, and forms a local vacuum low-pressure area in the negative pressure chamber (30); while a small part of the fluid flows through the tangential sand-disturbing swirl port (33) and the sand-disturbing nozzle (34) to form a high-speed rotating jet, which impacts and disturbs the sand bed (18) at the bottom of the well, and the sand-mixing liquid at the bottom of the well is sucked into the negative pressure suction port (27) of the jet pump body (16) under the action of the vacuum suction force; Step 3: The sand mixing liquid and the high-speed fluid ejected from the jet nozzle (31) are preliminarily mixed in the negative pressure chamber (30), and are further mixed when flowing through the throat (29) and the diffuser (28); the mixed fluid flows through the diffuser (28) with a continuously expanding cross-sectional diameter, and the kinetic energy is converted into pressure energy, and enters the vortex port (24) of the sand bailing tube body (15). The flow direction of the sand mixing liquid changes from axial to tangential, and the sand mixing liquid rotates in the annular hole of the sand bailing tube (23). Under the action of centrifugal force and gravity, the sand particles settle into the sand bailing tube (23), and the fluid flows into the double-wall drill pipe inner tube (21) and the double-wall drill pipe (14) and returns to the ground. After returning to the ground, it is processed by the return pipeline (5), the throttle valve (7), the separator (8), and the vibrating screen (9), completing the entire negative pressure jet sand bailing process.

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