Underground high-pressure water jet plug removal flowback device for oil field oil-water well

Abstract

The utility model belongs to the technical field of underground construction devices for oil-water wells in oil fields, and particularly relates to an underground high-pressure water jet unblocking and flowback device for oil-water wells in oil fields. Comprising an oil pipe, a plug valve, a sliding wellhead, a flowback device, a packer, a high-pressure water jet device and a circulating valve are installed on the oil pipe from top to bottom, a sleeve is installed below the sliding wellhead, the flowback device is provided with a formation liquid suction inlet, the formation liquid suction inlet is communicated with a nozzle through a formation liquid channel, and the nozzle is communicated with a negative pressure cavity. The negative pressure cavity is communicated with a diffusion cavity and a mixed liquid channel, the outer side of the high-pressure water jet device is rotationally connected with a rotary outer sleeve, a plurality of water outlet holes are formed in the high-pressure water jet device, and a plurality of eccentric water holes are obliquely formed in the rotary outer sleeve. According to the utility model, the unblocking and flowback processes are realized by one pipe column, the construction efficiency is high, the bearing pressure of the sleeve is small during flowback, the sleeve leakage is not caused, and the coverage and the unblocking range are large during unblocking construction.

Description

Technical Field

[0001] The utility model belongs to the technical field of downhole construction devices for oilfield oil and water wells, and particularly relates to an downhole high-pressure water jetting blockage-removing and drainage device for oilfield oil and water wells. Background Art

[0002] With the continuous development of oilfield development, the introduction of various production-increasing measures such as water injection and polymer injection, the blockage of oil and water wells has become increasingly serious. From the early migration of original particles in the formation, the blockage of oil flow channels by the precipitation of colloid, asphalt, wax, etc., to the expansion of clay minerals caused by water injection, the influence of external factors caused by substandard water quality, and the blockage of oil and water wells by polymers produced by polymer injection, the normal production of oil and water wells is seriously affected. Therefore, a comprehensive and powerful unblocking process device is needed to clear and discharge the formation blockage to restore the normal production of oil and water wells.

[0003] Existing unblocking technologies mainly rely on water flow to impact and vibrate the formation, or use nitrogen mixed discharge to generate negative pressure to pump the formation. There are also construction devices that use hydraulic power to generate negative pressure. These construction devices have low construction efficiency and are not very targeted. In addition, the current reverse circulation negative pressure device requires casing pressure, which is easy to cause casing leakage and has poor construction applicability. In the current water jet unblocking construction, the construction pipe string is a fixed pipe string, the jet area cannot cover the oil layer, and the unblocking range is only near the jet port, and the unblocking range is small. Summary of the invention

[0004] The utility model aims to provide an underground high-pressure water jet unblocking and return flow device for oil and water wells in oil fields, so as to solve the problems existing in the prior art.

[0005] The utility model solves the technical problem by adopting the following technical scheme: an underground high-pressure water jet unblocking and return flow device for oil and water wells in oil fields, comprising a casing, an oil pipe is sleeved in the casing, a plug valve, a sliding wellhead, a return flow device, a packer, a high-pressure water jet device, and a circulation valve are installed on the oil pipe from top to bottom, the sliding wellhead is installed on the top of the casing, the return flow device is provided with a formation fluid suction port, the formation fluid suction port is connected with a nozzle through a formation fluid channel, the nozzle is connected with a negative pressure chamber, the negative pressure chamber is connected with a diffusion chamber and a mixed liquid channel, a rotating outer sleeve is rotatably connected to the outer side of the high-pressure water jet device, a plurality of water outlet holes are provided on the high-pressure water jet device, and a plurality of eccentric water holes are inclinedly provided on the rotating outer sleeve.

[0006] Furthermore, the flowback device, the packer, the high-pressure water jet device, and the circulation valve are all located on the oil pipe in the casing.

[0007] Furthermore, the return device is in the shape of a circular tube as a whole, and the upper and lower ends of the return device are respectively a female buckle type and a male buckle type, and a plurality of mixed liquid outlets are arranged at the lower part of the return device.

[0008] Furthermore, a diffusion tube is inserted in the return device, the shape of the upper inner wall of the diffusion tube matches the nozzle, the nozzle is clamped on the upper part of the diffusion tube, the diffusion tube is threaded with a pressure cap above the nozzle, the outer wall of the pressure cap is threaded on the inner wall of the return device, the negative pressure chamber, the diffusion chamber, and the mixed liquid channel are located in the diffusion tube, there is a gap between the outer wall of the diffusion tube and the inner wall of the return device, a plurality of protrusions are provided on the outer wall of the diffusion tube at the position of the mixed liquid channel, and a plurality of protrusions are provided at corresponding positions of the return device, the protrusions and the protrusions cooperate and are plugged in with each other, there is a gap between the protrusion and the inner wall of the diffusion tube, the gap between the outer wall of the diffusion tube and the inner wall of the return device and the gap between the protrusion and the inner wall of the diffusion tube form a formation fluid channel.

[0009] Furthermore, the gland is hollow, and the gland is connected to the nozzle and the backflow device.

[0010] Furthermore, a clamping block is provided on the inner wall of the return flow device below the protrusion, and the diffusion pipe is clamped in the return flow device through the protrusion and the clamping block.

[0011] Furthermore, the upper part of the diffusion chamber is a cone that is thin at the top and thick at the bottom, and the lower part of the diffusion chamber is a cylinder. One end of the diffusion chamber is connected to the negative pressure chamber. The mixed liquid channel is located at one end of the diffusion chamber, and the mixed liquid channel is connected to the mixed liquid outlet.

[0012] Furthermore, the number of high-pressure water jet devices is at least one, and the high-pressure water jet device is in the shape of a circular tube as a whole. The upper and lower ends of the high-pressure water jet device are respectively a female buckle type and a male buckle type. The high-pressure water jet device and the rotating outer sleeve are symmetrically set with a damping assembly, a bearing, and a sealing packing. The rotating outer sleeve is rotatably connected to the outside of the high-pressure water jet device through the damping assembly, the bearing, and the sealing packing.

[0013] Furthermore, the water outlet hole and the eccentric water hole are at the same horizontal height, and an angle exists between the central axis of the eccentric water hole and the radial line of the rotating outer sleeve.

[0014] Furthermore, the angle between the central axis of the eccentric water hole and the radial line of the rotating outer sleeve is 45-60 degrees.

[0015] The utility model has the following beneficial effects:

[0016] 1. The utility model realizes the unblocking and backflow process in one trip of the pipe string, with high construction efficiency. The casing pressure is small during backflow, which will not cause casing leakage. The coverage area during unblocking construction is large, and the unblocking range is large.

[0017] 2. Through the inclined eccentric water hole, water flows into the high-pressure water jet device, causing the rotating jacket to rotate, thereby forming a pulse vibration to shock the blockage. Therefore, the unblocking construction covers a large area and has a large unblocking range.

[0018] 3. Through the flowback device, the formation fluid is returned to the oil casing annulus above the packer. The casing only bears the tension of the formation fluid, so the casing pressure is small and will not cause casing leakage.

[0019] 4. The whole pipe string adopts positive circulation construction, which has strong construction adaptability and can be used in wells with casing problems.

[0020] 5. During the flowback construction, the high-pressure water jet device rotates and oscillates in the opposite direction to stir the formation and further enhance the flowback effect.

[0021] 6. The flowback device is of split design. According to the effect of the unblocking construction, the appropriate diffusion pipe is selected to enhance the pertinence and effectiveness of the flowback construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the utility model.

[0023] Figure 2 It is a schematic diagram of the cross-sectional structure of the return flow device of the utility model.

[0024] Figure 3 The utility model is a schematic diagram of the cross-sectional structure of the high-pressure water jet device.

[0025] Figure 4 This utility model Figure 2 Schematic diagram of the cross-sectional structure at AA in the middle.

[0026] Figure 5 This utility model Figure 2 Schematic diagram of the cross-sectional structure at BB in the middle.

[0027] Figure 6 This utility model Figure 3 Schematic diagram of the cross-section structure at CC.

[0028] Among them: 1. oil pipe; 2. plug valve; 3. sliding wellhead; 4. return device; 401. formation fluid suction inlet; 402. formation fluid channel; 403. nozzle; 404. diffusion chamber; 405. mixed liquid channel; 406. negative pressure chamber; 407. mixed liquid outlet; 408. diffusion tube; 409. block; 410. gland; 411. bump; 412. protrusion; 5. packer; 6. high-pressure water jet device; 601. rotating sleeve; 602. water outlet; 603. eccentric water hole; 604. damping assembly; 605. bearing; 606. sealing packing; 7. circulation valve; 8. casing. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with specific embodiments and drawings.

[0030] like Figure 1-6As shown, a downhole high-pressure water jet unblocking and return flow device for oil and water wells in oil fields comprises a casing 8, an oil pipe 1 is sleeved inside the casing 8, a plug valve 2, a sliding wellhead 3, a return flow device 4, a packer 5, a high-pressure water jet device 6, and a circulation valve 7 are installed on the oil pipe 1 from top to bottom, the sliding wellhead 3 is installed on the top of the casing 8, the return flow device 4 is provided with a formation fluid suction port 401, the formation fluid suction port 401 is connected to a nozzle 403 through a formation fluid channel 402, the nozzle 403 is connected to a negative pressure chamber 406, the negative pressure chamber 406 is connected to a diffusion chamber 404 and a mixed liquid channel 405, the outer side of the high-pressure water jet device 6 is rotatably connected to a rotating outer sleeve 601, a plurality of water outlet holes 602 are provided on the high-pressure water jet device 6, and a plurality of eccentric water holes 603 are inclinedly provided on the rotating outer sleeve 601.

[0031] The flowback device 4 , the packer 5 , the high-pressure water jet device 6 , and the circulation valve 7 are all located on the oil pipe 1 inside the casing 8 .

[0032] The plug valve 2, the sliding wellhead 3, the packer 5, and the circulation valve 7 are all prior art and will not be described in detail again.

[0033] The flowback device 4 is in the shape of a round tube as a whole. The upper and lower ends of the flowback device 4 are respectively a female buckle type and a male buckle type, which are used to connect the oil pipe 1. The lower part of the flowback device 4 is provided with a plurality of mixed liquid outlets 407.

[0034] A diffusion pipe 408 is inserted in the backflow device 4. The shape of the inner wall of the upper part of the diffusion pipe 408 matches the nozzle 403. The nozzle 403 is clamped on the upper part of the diffusion pipe 408. The diffusion pipe 408 is threaded with a gland 410 above the nozzle 403. The outer wall of the gland 410 is threaded on the inner wall of the backflow device 4. The negative pressure chamber 406, the diffusion chamber 404, and the mixed liquid channel 405 are located in the diffusion pipe 408. The outer wall of the diffusion pipe 408 and the inner wall of the backflow device 4 are connected. There is a gap between them. The diffusion tube 408 is provided with a plurality of protrusions 411 on the outer wall at the position of the mixed liquid channel 405. The return device 4 is provided with a plurality of protrusions 412 at the corresponding positions. The protrusions 411 and the protrusions 412 cooperate with each other and are plugged into each other. There is a gap between the protrusions 412 and the inner wall of the diffusion tube 408. The gap between the outer wall of the diffusion tube 408 and the inner wall of the return device 4 and the gap between the protrusions 412 and the inner wall of the diffusion tube 408 form a formation fluid channel 402.

[0035] High-pressure water flow is sprayed from the nozzle 403 into the diffusion chamber 404. During this process, the water flow becomes narrower when passing through the nozzle 403, and becomes wider after entering the diffusion chamber 404. Under the influence of the Bernoulli effect, the negative pressure chamber 406 generates negative pressure, causing the formation fluid to be sucked into the oil pipe 1 from the circulation valve 7.

[0036] Under the limiting effect of the protrusion 412 , the convex block 411 enables the diffuser tube 408 to make the mixed liquid channel 405 directly face the mixed liquid outlet 407 when installed.

[0037] The pressure cap 410 is hollow, and the pressure cap 410 is connected to the nozzle 403 and the backflow device 4 .

[0038] The backflow device 4 is provided with a clamping block 409 on the inner wall below the protrusion 411, and the diffuser 408 is clamped in the backflow device 4 through the protrusion 411 and the clamping block 409. The clamping block 409 is used to support the diffuser 408.

[0039] The upper part of the diffusion chamber 404 is a cone that is thin at the top and thick at the bottom, and the lower part of the diffusion chamber 404 is a cylinder. One end of the cone of the diffusion chamber 404 is connected to the negative pressure chamber 406. The mixed liquid channel 405 is located at one end of the cylinder of the diffusion chamber 404, and the mixed liquid channel 405 is connected to the mixed liquid outlet 407.

[0040] The number of high-pressure water jet devices 6 is at least one, and the high-pressure water jet device 6 is in the shape of a circular tube as a whole. The upper and lower ends of the high-pressure water jet device 6 are respectively a female buckle type and a male buckle type. The damping assembly 604, the bearing 605, and the sealing packing 606 are symmetrically mounted between the high-pressure water jet device 6 and the rotating sleeve 601. The rotating sleeve 601 is rotatably connected to the outside of the high-pressure water jet device 6 through the damping assembly 604, the bearing 605, and the sealing packing 606.

[0041] The water outlet hole 602 and the eccentric water hole 603 are at the same level, and the angle between the central axis of the eccentric water hole 603 and the radial line of the rotating sleeve 601 is 45-60 degrees.

[0042] The working principle of the utility model is:

[0043] During unblocking construction, the diffuser 408 in the return device 4 is pulled out. At this time, the return device 4 is in an inoperative state, the plug valve 2 is opened, and the high-pressure water flows from the oil pipe 1 into the high-pressure water jet device 6. The circulation valve 7 is closed under positive pressure, and the water flows from the water outlet 602 and the eccentric water hole 603 at high speed to the annular cavity between the oil pipe 1 and the casing 8. The packer 5 is unsealed. Since the eccentric water hole 603 is inclined relative to the radial line of the rotating sleeve 601, the high-pressure water drives the rotating sleeve 601 to rotate. During the rotation process, when the water outlet 602 and the eccentric water are positively charged, the flow rate is large, otherwise the flow rate is small, thereby forming a pulse oscillation to shock the blockage.

[0044] During the flowback construction, the diffusion pipe 408 is inserted into the flowback device 4, and the gland 410 is screwed on so that the gland 410 presses the nozzle 403, and the plug valve 2 is opened. The high-pressure water flows into the flowback device 4 from the oil pipe 1 and is sprayed into the diffusion chamber 404 from the nozzle 403. In this process, the water flow becomes narrower when passing through the nozzle 403, and becomes wider after entering the diffusion chamber 404. Under the influence of the Bernoulli effect, the negative pressure chamber 406 generates negative pressure, and the circulation valve 7 is opened, so that the formation fluid is sucked into the oil pipe 1 from the circulation valve 7, and is sucked into the negative pressure chamber 406 through the high-pressure water jet device 6, the formation fluid suction port 401, and the formation fluid channel 402, and is brought into the diffusion chamber 404 by the water flow for mixing. Then the mixed liquid is discharged into the annular cavity between the oil pipe 1 and the casing 8 through the mixed liquid channel 405. At this time, the packer 5 is closed, and the discharged mixed liquid returns to the ground. At the same time, when the formation fluid passes through the high-pressure water jet device 6, it is caused to rotate and vibrate in the opposite direction to stir the formation and enhance the flowback effect.

[0045] The above-described embodiments are merely descriptions of preferred implementations of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made by ordinary persons in the art to the technical solution of the present invention shall fall within the scope of protection of the present invention.

[0046] The technology, shape and structure parts not described in detail in the present invention are all known technologies.

Claims

1. A downhole high-pressure water jet unblocking and flowback device for oil and water wells in oil fields, characterized in that: It includes a casing, in which an oil pipe is sleeved, and the oil pipe is installed with a plug valve, a sliding wellhead, a return device, a packer, a high-pressure water jet device, and a circulation valve from top to bottom. The sliding wellhead is installed at the top of the casing, and the return device is provided with a formation fluid suction inlet. The formation fluid suction inlet is connected to a nozzle through a formation fluid channel, and the nozzle is connected to a negative pressure chamber, and the negative pressure chamber is connected to a diffusion chamber and a mixed liquid channel. The outer side of the high-pressure water jet device is rotatably connected to a rotating outer jacket, and the high-pressure water jet device is provided with a plurality of water outlet holes, and the rotating outer jacket is inclinedly provided with a plurality of eccentric water holes.

2. The downhole high-pressure water jet unblocking and flowback device for oil and water wells in oil fields according to claim 1 is characterized in that: The flowback device, the packer, the high-pressure water jet device and the circulation valve are all located on the oil pipe in the casing.

3. The downhole high-pressure water jet unblocking and flowback device for oil and water wells in oil fields according to claim 2 is characterized in that: The return device is in the shape of a circular tube as a whole, and the upper and lower ends of the return device are respectively a female buckle type and a male buckle type, and a plurality of mixed liquid outlets are arranged at the lower part of the return device.

4. The downhole high-pressure water jet unblocking and flowback device for oil and water wells in oil fields according to claim 3 is characterized in that: A diffusion tube is inserted in the return device, the shape of the inner wall of the upper part of the diffusion tube matches the nozzle, the nozzle is clamped on the upper part of the diffusion tube, the diffusion tube is threaded with a pressure cap above the nozzle, the outer wall of the pressure cap is threaded on the inner wall of the return device, the negative pressure chamber, the diffusion chamber, and the mixed liquid channel are located in the diffusion tube, there is a gap between the outer wall of the diffusion tube and the inner wall of the return device, a plurality of protrusions are provided on the outer wall of the diffusion tube at the position of the mixed liquid channel, and a plurality of protrusions are provided at corresponding positions of the return device, the protrusions and the protrusions are matched and plugged with each other, there is a gap between the protrusion and the inner wall of the diffusion tube, the gap between the outer wall of the diffusion tube and the inner wall of the return device and the gap between the protrusion and the inner wall of the diffusion tube form a formation fluid channel.

5. The downhole high-pressure water jet unblocking and flowback device for oil and water wells in oil fields according to claim 4 is characterized in that: The gland is hollow and connected with the nozzle and the backflow device.

6. The downhole high-pressure water jet unblocking and flowback device for oil and water wells in oil fields according to claim 4, characterized in that: The return flow device is provided with a clamping block on the inner wall below the protrusion, and the diffusion pipe is clamped in the return flow device through the protrusion and the clamping block.

7. The downhole high-pressure water jet unblocking and flowback device for oil and water wells in oil fields according to claim 4 is characterized in that: The upper part of the diffusion chamber is a conical shape that is thin at the top and thick at the bottom, and the lower part of the diffusion chamber is a cylindrical shape. One end of the diffusion chamber is connected to the negative pressure chamber. The mixed liquid channel is located at one end of the diffusion chamber, and the mixed liquid channel is connected to the mixed liquid outlet.

8. The downhole high-pressure water jet unblocking and flowback device for oil and water wells in oil fields according to claim 2, characterized in that: The number of the high-pressure water jet device is at least one, and the high-pressure water jet device is in the shape of a circular tube as a whole. The upper and lower ends of the high-pressure water jet device are respectively a female buckle type and a male buckle type. The high-pressure water jet device and the rotating outer sleeve are symmetrically set with a damping assembly, a bearing, and a sealing packing. The rotating outer sleeve is rotatably connected to the outside of the high-pressure water jet device through the damping assembly, the bearing, and the sealing packing.

9. The downhole high-pressure water jet unblocking and flowback device for oil and water wells in oil fields according to claim 8, characterized in that: The water outlet hole and the eccentric water hole have the same horizontal height, and the central axis of the eccentric water hole and the radial line of the rotating outer sleeve have an included angle.

10. The downhole high-pressure water jet unblocking and flowback device for oil and water wells in oil fields according to claim 9, characterized in that: The angle between the central axis of the eccentric water hole and the radial line of the rotating outer sleeve is 45-60 degrees.

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