Integrated pipe string for side tracking horizontal well with large diameter and open hole filling and acid washing and operation method thereof

Abstract

The application discloses a sidetracking horizontal well large-diameter open-hole filling and acid washing integrated pipe column and a running method thereof. The pipe column comprises an outer pipe column and an inner pipe column, the inner pipe column is arranged in the outer pipe column, and a casing is arranged outside the outer pipe column. The outer pipe column comprises, from top to bottom, a locking device, an outer channel, a releasing device, a fishing device, a slip, a rubber sleeve, a reverse washing device, a filling outer tool, a backflow prevention device, an open-hole screen pipe and an acid washing outer sealing device. The inner pipe column comprises, from top to bottom, an inner channel, a filling inner tool, a check valve, a jetting pipe, an acid washing inner sealing device, a jet tool, a ball catching device and a bottom liquid flow port. The running method comprises the following steps: drilling fluid injection, pipe releasing, normal mud replacement, tubing pressure test, opening of the locking device, filling, reverse well washing without moving the pipe column, normal rotation releasing, segmented acid washing construction, reverse well washing until the outlet is clean and pipe column lifting. The application has the advantages of short construction period, effective prevention of well wall collapse, short construction period, high safety, and good construction effect.

Description

TECHNICAL FIELD

[0001] The present application relates to a pipe string for filling and acid washing of a large-diameter open hole of a sidetracked horizontal well, which is suitable for filling and acid washing construction of a sidetracked open hole horizontal well and belongs to the technical field of filling and acid washing. BACKGROUND

[0002] At present, during the completion process of a sidetracked open hole horizontal well, a bottom filling method is adopted, and the filling density is low, which greatly affects the sand prevention effect and production level of the sidetracked horizontal well. On the other hand, the traditional sand prevention completion method after drilling has a long cycle and is easy to cause well wall collapse and damage to the reservoir caused by drilling mud. In addition, due to the small well passage of the completion tool, there are problems such as difficulty in later operation and affecting the production capacity of the horizontal well.

[0003] In view of the above problems, a large-diameter open hole filling and acid washing integrated pipe string and method for a sidetracked horizontal well are provided. SUMMARY

[0004] The present application provides a large-diameter open hole filling and acid washing integrated pipe string for a sidetracked horizontal well, which has a short construction cycle, high safety and good construction effect, and simultaneously provides a running method of the pipe string.

[0005] The large-diameter open hole filling and acid washing integrated pipe string for a sidetracked horizontal well of the present application adopts the following technical scheme:

[0006] The pipe string comprises an outer pipe string and an inner pipe string, the inner pipe string is arranged in the outer pipe string, a sleeve is arranged on the outer side of the outer pipe string, the inner pipe string is sleeved on the oil pipe, and a cavity between the oil pipe and the sleeve forms an oil-casing annulus; the outer pipe string comprises, from top to bottom, a locking device, a bridge-type clamped-wall outer passage, a releasing device, a fishing built-in device, a slip, a rubber sleeve, a backwashing device, a filling outer tool, an anti-return device, an open hole screen pipe and an acid washing outer sealing device; the inner pipe string comprises, from top to bottom, a bridge-type clamped-wall inner passage, a filling inner tool, a check valve, a flushing pipe, an acid washing inner sealing device, a jet tool, a ball catching device and a bottom liquid flow port.

[0007] The locking device is divided into an upper part and a lower part, the upper part and the lower part are engaged and connected through locking pins, the upper part is connected with the sleeve, and the lower part is connected with the releasing device. When the locking device is not opened, the upper part and the lower part are connected together through the locking pins, and there is no relative movement between the two; when the locking pins are cut off under a certain pressure, the upper part and the lower part are disconnected, and the two can move relative to each other.

[0008] The bridge-type clamped-wall outer passage and the bridge-type clamped-wall inner passage are not connected with each other and are respectively used for forward and reverse liquid flow passages. The upper part of the outer passage is provided with a clamped-wall liquid flow port communicated with the oil pipe.

[0009] The upper part of the releasing device is connected with the outer passage of the bridge-type wall, and the lower part is connected with the slip, which is used for releasing the pipe column in the positive rotation.

[0010] The fishing built-in device is installed on the inner wall of the releasing device, and is connected with the pin, which is used for fishing the tool.

[0011] The upper part of the slip is connected with the releasing device, and the lower part is abutted on the rubber cylinder. When the slip is opened, the rubber cylinder is moved up under the pushing of the liquid cylinder, and the reverse washing passage groove is left. The inner wall of the slip is provided with the through slip groove, which can be used as the liquid flow passage during the reverse washing.

[0012] The upper part of the rubber cylinder is connected with the slip, and the lower part is connected with the reverse washing device. The inner wall of the rubber cylinder is provided with the through rubber cylinder groove, which is communicated with the slip groove and penetrates to the reverse washing device, and is used as the liquid flow passage during the reverse washing.

[0013] The reverse washing device is located at the lower part of the rubber cylinder, and is used as the liquid flow passage during the reverse washing. When the rubber cylinder is inflated and sealed, the reverse washing port of the reverse washing device is left, and the reverse washing is performed. When the rubber cylinder is normal (not inflated and sealed), the reverse washing device is in the closed state.

[0014] The filling outer tool is used as the liquid flow passage during the sand prevention and filling. The filling outer tool comprises a base and a filling sliding sleeve. The filling sliding sleeve is connected with the base through the pin. The upper end of the base is provided with the closing step. The base is provided with the filling port. When the pressure reaches a certain value, the pin is cut off, the filling sliding sleeve is lowered, and the filling port is leaked out, so that the sand prevention and filling operation can be performed.

[0015] The anti-backflow device is the one-way leather cup composite screen structure. When the liquid flow is returned from the lower part of the anti-backflow device, the sand in the liquid flow is blocked, and the liquid flows out.

[0016] The acid washing outer sealing device is connected with the open hole screen pipe through the screw thread. The acid washing outer sealing device can be set according to the requirement, and is arranged at the appropriate position of the open hole screen pipe. The acid washing sealing device is arranged in the V-shaped sealing mode, and is in the interference fit with the acid washing inner sealing device. When the two sealing devices are opposite to each other, the sealing can be formed.

[0017] The bridge-type wall inner passage is provided with the wall sliding sleeve, and the inner side of the wall sliding sleeve is provided with the wall ball seat. The outer diameter of the ball dropped from the oil pipe is smaller than the minimum inner diameter of the jet tool. After the ball dropped from the oil pipe is dropped into the wall ball seat, when the pressure reaches a certain pressure, the wall sliding sleeve is lowered, and the wall liquid flow port of the bridge-type wall outer passage is closed. When the pressure continues to increase, the wall ball seat is knocked down, and the pressure continues to increase to 25-30 MPa. The one-way valve is knocked down and falls into the ball catching device at the bottom.

[0018] The closing claw is arranged on the filling inner tool. When the pipe column is lifted, the closing claw drives the closing step of the filling outer tool to close the filling port of the filling outer tool.

[0019] The single flow valve only allows liquid flow from bottom to top.

[0020] The acid washing inner sealing device is connected to the wash pipe, and the maximum outer diameter of the acid washing inner sealing device is smaller than the minimum inner diameter of the closing step of the filling outer tool; the acid washing inner sealing device cooperates with the acid washing outer sealing device to form a seal for forming a sectional seal for the open hole screen pipe during acid washing.

[0021] The jetting tool adopts existing jetting devices, and a plurality of jetting devices are arranged according to needs.

[0022] The ball catching device is located at the lower part of the jetting tool, and is a metal mesh bag with a certain elasticity, which is used to accommodate small parts such as balls falling from the upper part, and the upper part is slightly smaller and elastic, so that the object can be accommodated therein and is not easy to fall out.

[0023] The bottom liquid flow port allows liquid flow to pass in one direction from bottom to top.

[0024] The releasing device, the fishing built-in device, the slip, the single flow valve and the jetting tool adopt existing structures, and all belong to the known prior art.

[0025] The pipe string for filling and acid washing of a large-diameter open hole of a horizontal well drilled by lateral drilling comprises the following steps:

[0026] (1) tripping out and filling liquid:

[0027] (2) lowering the connected inner and outer pipe strings into the well; if the pipe string is not easy to lower, the pipe string is lowered while being rotated.

[0028] (3) normal mud displacement;

[0029] (4) tubing pressure test and setting of the rubber sleeve. When the pressure is 6-8 MPa, the slip is opened, and the rubber sleeve is inflated and sealed,

[0030] (5) opening the locking device and continuing to press to 10-12 MPa, so that the upper and lower parts of the locking device are separated;

[0031] (6) filling; further pressure test, cutting the pin of the filling sliding sleeve, so that the filling port is opened, at this time, the filling slurry is pumped from the tubing, enters the open hole annulus through the outer channel and the filling port on the filling outer tool, and returns to the wash pipe from the bottom liquid flow port, and then returns through the single flow valve and the bridge-type double-wall inner channel, and then returns through the tubing-casing annulus (the cavity between the tubing and the casing);

[0032] (7) reverse well washing without moving the pipe string; the washing fluid is injected from the tubing-casing annulus (the cavity between the tubing and the casing), enters the outer channel through the slip (the gap between the slip teeth and the slip groove), the reverse washing device and the filling port on the filling outer tool, and then returns through the tubing;

[0033] (8) Positive rotation release;

[0034] (9) Staged acid washing operation:

[0035] Lifting the inner string to the designed position, the acid washing inner sealing device and the acid washing outer sealing device are in direct contact to form a seal; during acid washing, the ball is thrown and seated on the bridge-type straddle ball seat in the outer passage, the tubing is pressed, the straddle sliding sleeve in the inner passage of the bridge-type straddle is dropped, the straddle flow port of the tubing leading to the outer passage of the bridge-type straddle is closed, when the pressure continues to increase, the straddle ball seat in the outer passage of the bridge-type straddle is knocked off (the straddle ball seat is knocked off together with the ball), and the pressure continues to increase to 25-30 MPa, the check valve is knocked off and falls into the ball catching device (the ball, the straddle ball seat and the check valve fall into the ball catching device together), at this time, the first stage of the open hole screen pipe jetting acid washing and plugging removal is carried out, the casing gate is closed, the acid liquid enters from the tubing, and the designed amount of acid liquid is squeezed into the first stage of the open hole screen pipe through the jetting tool, and then the casing gate is opened for well washing;

[0036] Then, the above operation is repeated until the jetting acid washing and plugging removal of all open hole screen pipes are completed; under the action of the anti-return device, during well washing, the washing fluid flows out from the anti-return device hole, and the packing sand is left, effectively preventing the return of the packing sand;

[0037] (10) Reverse well washing to clean outlet:

[0038] (11) String lifting: lifting the inner string after the release.

[0039] Compared with the prior art, the present application has the following remarkable effects:

[0040] 1. The sand prevention and acid washing integrated operation after the drilling of the sidetracked horizontal well is realized, the construction period is short, the well wall collapse is effectively prevented, and the drilling mud pollution is reduced;

[0041] 2. The top packing method is adopted, which has the support of the horizontal well packing theory, and the packing compactness of the horizontal well is effectively improved

[0042] 3. The string is provided with a locking device, which can be lowered while being rotated during the lowering of the string, effectively solving the problem that the string is not easy to be lowered due to the small borehole and long well section of the sidetracked horizontal well.

[0043] 4. The string tool adopts the bridge-type straddle passage mode, the drift diameter is large, and the displacement is large;

[0044] 5. The string is provided with a non-moving string reverse washing device, which can realize non-moving string reverse well washing through the reverse washing fluid passage design, and improve the operation safety.

[0045] 6. The pipe column adopts the mode of setting V-shaped seal in the sealing device, ensures effective sealing during segmented pickling, and guarantees pickling construction effect. The pipe column and method are improved through tool and process improvement, have short construction period, high safety, and good construction effect, and have important significance for fully exerting the productivity of the lateral drilling open hole horizontal well and improving sand prevention production effect. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 is a structural schematic diagram of the drill horizontal well large-diameter open hole filling and pickling integrated pipe column of the present application.

[0047] Figure 2 is a flow process schematic diagram of circulating filling fluid.

[0048] Figure 3 is a flow process schematic diagram of reverse washing well fluid after filling.

[0049] Figure 4 is a flow process schematic diagram of acid squeezing.

[0050] Figure 5 is a flow process schematic diagram of acid pickling.

[0051] Figure 6 is a flow process schematic diagram of reverse circulating washing well fluid after acid pickling.

[0052] In the figure: 1, casing, 2, open hole annulus, 3, tubing, 4, locking device, 401, locking pin, 5, bridge-type double-wall outer passage, 501, double-wall flow port, 6, releasing device, 7, fishing built-in device, 8, slip, 801, slip groove, 9, rubber sleeve, 901, rubber sleeve groove, 10, reverse washing device, 11, filling outer tool, 1101, closing step, 1102, filling port, 1103, filling sliding sleeve pin, 1104, filling sliding sleeve, 12, anti-backflow device, 13, open hole screen pipe, 14, pickling outer sealing device; 15, bridge-type double-wall inner passage, 1501, double-wall sliding sleeve, 1502, double-wall ball seat, 16, filling inner tool, 1601, closing claw, 17, one-way valve, 18, jet pipe, 19, pickling inner sealing device, 20, jet tool, 21, ball catching device, 22, bottom flow port. DETAILED DESCRIPTION

[0053] The detailed description and technical content of the present application are described as follows with the aid of the drawings, however, the drawings are only for reference and description, and are not used to limit the present application.

[0054] As Figure 1The side-tracking horizontal well large-diameter open-hole filling and acid washing integrated pipe column mainly comprises an outer pipe column and an inner pipe column, the inner pipe column is arranged in the outer pipe column, a sleeve 1 is arranged outside the outer pipe column, a cavity between the outer pipe column and the open-hole wall forms an open-hole annulus 2, and the inner pipe column is threadedly connected with a tubing 3. The outer pipe column is composed of a locking device 4, a bridge-type clamped-wall outer passage 5, a releasing device 6, a fishing built-in device 7, a slip 8, a rubber sleeve 9, a reverse washing device 10, a filling outer tool 11, a backflow prevention device 12, an open-hole screen pipe 13 and an acid washing outer sealing device 14 connected in sequence from top to bottom. The inner pipe column is composed of a bridge-type clamped-wall inner passage 15, a filling inner tool 16, a one-way valve 17, a flushing pipe 28, an acid washing inner sealing device 19, a jet tool 20, a ball catching device 21 and a bottom liquid flow port 22 connected in sequence from top to bottom.

[0055] The locking device 4 is divided into two parts, the upper part and the lower part are engaged (inserted) together (in the form of gear engagement), and are connected through a locking pin 401, the upper part is connected with the sleeve 1 in a threaded manner, and the lower part of the locking device 4 is connected with the releasing device 6. When the locking device 4 is not opened, the upper part and the lower part are connected together, and there is no relative movement between them; when the locking pin 401 is cut off under a certain pressure, the locking device 4 is opened, the upper part and the lower part are separated, and there is relative movement between them.

[0056] The bridge-type clamped-wall outer passage 5 and the bridge-type clamped-wall inner passage 15 are not connected with each other, and are respectively used for forward and reverse liquid flow passages. The bridge-type clamped-wall outer passage 5 is provided with a clamped-wall liquid flow port 501 communicated with the tubing 3.

[0057] The upper part of the releasing device 6 is connected with the bridge-type clamped-wall outer passage 5, and the lower part is connected with the slip 8, which is used for normal rotation releasing of the pipe column.

[0058] The fishing built-in device 7 is installed on the inner wall of the releasing device 6 and is connected together through a pin. It is used for tool fishing.

[0059] The upper part of the slip 8 is connected with the releasing device 6, and the lower part is abutted on a wedge-shaped seat of the rubber sleeve 9. When the slip 8 is opened, the rubber sleeve 9 is pushed downward to swell and seal. The inner wall of the slip 8 is provided with a slip groove 801, which is used for liquid flow passage during reverse washing.

[0060] The upper part of the rubber sleeve 9 is connected with the slip 8, and the lower part is connected with the reverse washing device 10. The inner wall of the rubber sleeve 9 is provided with a rubber sleeve groove 901, which is communicated with the slip groove 801 and penetrates to the reverse washing device 10, and is used for liquid flow passage during reverse washing.

[0061] The reverse washing device 10 is located at the lower part of the rubber sleeve 9. When the rubber sleeve 9 swells, the reverse washing port of the reverse washing device 10 is left, and when the rubber sleeve 9 does not swell normally, the reverse washing device 10 is in a closed state, and there is no communication here.

[0062] The packing outer tool 11 is used to pack the flow channel when sand prevention is performed. The packing outer tool 11 comprises a base and a packing sliding sleeve 1104 connected to the base through a packing sliding sleeve pin 1103. A closing step 1101 is arranged at the upper end of the base, and a packing port 1102 is arranged on the base. When the pressure reaches a certain value, the packing sliding sleeve pin 1103 is sheared, the packing sliding sleeve 1104 descends, and the packing port 1102 leaks out, so that the sand prevention packing operation can be performed.

[0063] The anti-backflow device 12 is a one-way cup-shaped screen structure. When the liquid flow returns from the lower part of the open hole annulus 2, the anti-backflow device 12 blocks the sand in the liquid flow, and the liquid flows out.

[0064] The acid washing outer sealing device 14 is connected with the open hole screen pipe 13 in a threaded manner. The acid washing outer sealing device 14 can be arranged as required and arranged at a proper position of the open hole screen pipe 13. The acid washing outer sealing device 14 is arranged in a V-shaped sealing manner and is in interference fit with the acid washing inner sealing device. When the two are opposite to each other, a seal can be formed.

[0065] The bridge-type double-wall inner passage 15 is arranged with a double-wall sliding sleeve 1501, and the inner side of the double-wall sliding sleeve 1501 is arranged with a double-wall ball seat 1502. The outer diameter of the ball dropped from the oil pipe is smaller than the minimum inner diameter of the jet tool 20. When the ball dropped from the oil pipe falls into the double-wall ball seat 1502, the double-wall sliding sleeve 1501 falls when the pressure reaches a certain pressure, and the double-wall flow port 501 of the bridge-type double-wall outer passage 5 is closed. When the pressure continues to increase, the double-wall ball seat 1502 falls, and when the pressure continues to increase to 25-30 MPa, the check valve 17 falls into the ball catching device 21 at the bottom after the check valve 17 is knocked off from the packing inner tool 16 and falls into the oil pipe 3.

[0066] The packing inner tool 16 is arranged with a closing claw 1601 at the bottom. When the pipe string is lifted, the closing claw 1601 drives the closing step 1101 to close the packing port 1102 of the packing outer tool 11.

[0067] The check valve 17 only allows the liquid flow to pass from bottom to top.

[0068] The acid washing inner sealing device 19 is connected to the jet pipe 18. The maximum outer diameter of the acid washing inner sealing device 19 is smaller than the minimum inner diameter of the closing step 1101 of the packing outer tool 11. The acid washing inner sealing device 19 cooperates with the acid washing outer sealing device 14 to form a seal and is used to form a segmented seal for the open hole screen pipe 13 during acid washing.

[0069] The jet tool 20 (existing jet) can be arranged as required.

[0070] The ball catching device 21 is located at the lower part of the jet tool 20. Figure 1The right side of the middle is a metal mesh bag with certain elasticity, which is used to accommodate the upper part of the ball and other small parts. The upper part of the opening is slightly smaller and elastic, and the object can be accommodated after entering.

[0071] The bottom flow port 22 only allows liquid to flow from bottom to top.

[0072] The method for filling and acid washing of large-diameter open hole of lateral drilling horizontal well by the pipe string with the above structure comprises the following steps:

[0073] 1. Tripping in and pumping liquid;

[0074] 2. Lowering the pipe string

[0075] Lower the connected inner and outer pipe strings into the well. If the pipe string cannot be lowered into the well, rotate the pipe string and lower the pipe string at the same time.

[0076] 3. Normal mud displacement;

[0077] 4. Press the tubing 3 and set the rubber sleeve. When the pressure is 6-8 MPa, the slips 8 are opened, the rubber sleeve 9 is inflated, and the rubber sleeve setting is completed.

[0078] 5. Open the locking device 4, continue to press about 10-12 MPa, and the upper and lower parts of the locking device 4 are separated.

[0079] 6. Filling

[0080] Further press, cut the filling sleeve pin 1103, open the filling port 1102, at this time, pump the filling sand slurry from the tubing 3, the sand slurry enters the open hole annulus 2 from the tubing 3 through the bridge type cladding outer passage 5, the filling port 1102 on the filling outer tool 11, and returns to the pipe 18 from the bottom flow port 22, through the single-flow valve 17 and the bridge type cladding inner passage 15, and then returns from the oil jacket annulus (the cavity between the tubing 3 and the casing 1);

[0081] The circulation filling liquid flow process is shown in Figure 2 .

[0082] 7. Reverse washing well without moving the pipe string

[0083] The washing well liquid is injected from the oil jacket annulus (the cavity between the tubing 3 and the casing 1), through the gap of the slip tooth, the slip groove 801 and the reverse washing device 10, and then enters the bridge type cladding outer passage 5 through the filling port 1102 on the filling outer tool 11, and returns from the tubing 3.

[0084] The filling liquid flow process after the pipe string is not moved is shown in Figure 3 .

[0085] 8. Normal rotation and releasing;

[0086] 9. Subsection acid washing construction

[0087] Raise the inner tubing to the designed position, and the pickling inner sealing device 19 and the pickling outer sealing device 14 are aligned to form a seal. During pickling, the ball is thrown and sits on the clamping ball seat 1502 of the bridge-type clamping outer channel 5. Pressure is applied from the oil pipe 3, causing the clamping sleeve 1501 of the bridge-type clamping inner channel 15 to fall, closing the clamping liquid outlet 501 of the oil pipe 3 to the bridge-type clamping outer channel 5. As the pressure continues to increase, the clamping ball seat 1502 is knocked off (both the clamping ball seat 1502 and the ball are knocked off). When the pressure continues to rise to 25-30 MPa, the check valve 17 is knocked off, and together they fall into the ball-catching device 21 at the bottom (the ball, the clamping ball seat 1502, and the check valve 17 fall into the ball-catching device 21). At this time, the first stage of open-eye screen tube 13 jet pickling and unblocking can be performed. After closing the casing 1 gate, acid enters from the tubing 3, and is injected through the flushing pipe 18 and the jetting tool 20 to the first open hole screen pipe 13. Then, the casing 1 gate is opened, and the well is flushed for one week.

[0088] Then, repeat the above operation until all open-hole screens 13 have been unblocked by jet acid washing. Under the action of the anti-backflow device 12, during well washing, the washing fluid flows out from the orifice of the anti-backflow device 12, while the filling sand is left behind, effectively preventing the backflow of the filling sand.

[0089] The flow path of the liquid during acid injection is as follows: Figure 4 As shown. The flow path of the pickling liquid is as follows. Figure 5 As shown.

[0090] 9. Thoroughly backwash the well until the outlet is clean.

[0091] The well-washing fluid enters from the annulus of the casing, passes through the gap of the slip teeth of the slip 8, the slip groove 801, the backwashing device 10, and then enters the bridge-type clamp wall outer channel 5 through the filling port 1102 on the filling external tool 11, and returns through the tubing 3.

[0092] The flow path of the reverse circulation well washing fluid after acid washing is as follows: Figure 6 As shown.

[0093] 10. Retrieve the tubing: Remove the inner tubing after it has been released.

[0094] The method of the present application adopts top filling mode, has alpha wave and beta wave filling theoretical support, and can further improve filling density through parameter optimization; secondly, the drilling sand prevention completion and acid washing filling integrated construction is adopted, the cycle is short, the well wall collapse is effectively prevented, and the reservoir damage is reduced; in addition, the pipe string is designed with a locking device, can be lowered into while being positively rotated in the process of lowering the pipe string, effectively solves the problem that the pipe string is not easy to be lowered into due to small borehole, long well section and other reasons of the sidetracked horizontal well. In addition, the pipe string tool adopts a bridge type clamped wall type passage, has large drift diameter and large displacement; and can realize reverse well washing without moving the pipe string, and improves the operation safety. At the same time, the pipe string adopts the mode that a V-shaped seal is arranged in the sealing cylinder, ensures the sealing effect during acid washing, and ensures the safety of acid washing construction.

[0095] The above only describes the preferred embodiments of the present application, and is not used to limit the protection scope of the present application, and other equivalent changes applied the technical scheme spirit of the present application shall belong to the protection scope of the present application.

Claims

1. A large-diameter open-hole packing and acid washing integrated tubing string for side-drilling horizontal wells, characterized in that: The pipe string comprises an outer pipe column and an inner pipe column, the inner pipe column is arranged in the outer pipe column, a sleeve is arranged outside the outer pipe column, the inner pipe column is sleeved on the oil pipe, and a cavity between the oil pipe and the sleeve forms an oil-casing annulus; the outer pipe column comprises, from top to bottom, a locking device, a bridge-type sandwich outer passage, a releasing device, a fishing built-in device, a slip, a rubber sleeve, a reverse washing device, a filling outer tool, a reverse flow prevention device, a bare hole screen pipe and an acid washing outer sealing device; the inner pipe column comprises, from top to bottom, a bridge-type sandwich inner passage, a filling inner tool, a check valve, a jet pipe, an acid washing inner sealing device, a jetting tool, a ball catching device and a bottom flow port; The locking device is divided into an upper part and a lower part, the upper part and the lower part are engaged and connected through locking pins, the upper part is connected with the sleeve, and the lower part is connected with the releasing device; The bridge-type sandwich outer passage and the bridge-type sandwich inner passage are not communicated with each other and are respectively used for forward and reverse liquid flow passages; an upper part of the bridge-type sandwich outer passage is provided with a sandwich liquid flow port communicated with the oil pipe; A sandwich sliding sleeve is arranged in the bridge-type sandwich inner passage, and a sandwich ball seat is arranged on an inner side of the sandwich sliding sleeve; The operation process of the large-diameter bare hole filling and acid washing integrated pipe string for the horizontal well of the side drilling comprises the following steps: (1) tripping in and pumping liquid; (2) lowering the connected inner and outer pipe columns into the well; if the pipe column is not easy to be lowered into the well, the pipe column is lowered into the well while being rotated in a positive direction; (3) replacing mud in a positive direction; (4) pressurizing the oil pipe and setting the rubber sleeve; when the pressure is 6-8 MPa, the slip is opened, the rubber sleeve is inflated and set, and the setting of the rubber sleeve is completed; (5) opening the locking device and continuing to pressurize to 10-12 MPa, so that the upper and lower parts of the locking device are separated; (6) filling; further pressurizing, cutting the pin of the filling sliding sleeve, opening the filling port, pumping filling slurry into the oil pipe, and making the slurry enter the bare hole annulus through the oil pipe, the bridge-type sandwich outer passage and the filling port of the filling outer tool, return to the jet pipe through the bottom flow port, pass through the check valve and the bridge-type sandwich inner passage, and return to the oil-casing annulus; (7) reverse well washing without moving the pipe column; the washing liquid is injected from the oil-casing annulus, enters the bridge-type sandwich outer passage through the slip, the reverse washing device and the filling port of the filling outer tool, and returns to the oil pipe; (8) releasing in a positive direction; (9) staged acid washing construction: lifting the inner pipe column to a designed position, the acid washing inner sealing device and the acid washing outer sealing device being opposite to each other to form a seal; during acid washing, a ball is thrown and seated on the sandwich ball seat of the bridge-type sandwich outer passage, the bridge-type sandwich inner passage is lowered by pressurizing the oil pipe, the sandwich liquid flow port of the oil pipe to the bridge-type sandwich outer passage is closed, the sandwich ball seat of the bridge-type sandwich outer passage is knocked down when the pressure continues to increase, the check valve is knocked down when the pressure continues to increase to 25-30 MPa, and the check valve and the ball fall into the ball catching device; at this time, the first bare hole screen pipe jetting acid washing is performed, the sleeve gate is closed, the acid liquid enters the oil pipe, is extruded to a designed amount of acid liquid in the first bare hole screen pipe through the jet pipe and the jetting tool, and then the sleeve gate is opened for well washing; Then, the above operation is repeated until the jetting acid washing of all the bare hole screen pipes is completed; under the action of the reverse flow prevention device, the washing liquid flows out from the hole of the reverse flow prevention device during well washing, and the filling sand is left, so that the reverse flow of the filling sand is effectively prevented. (10) backwashing to outlet clean; (11) pipe column: after the release of the inner pipe column.

2. The sidetracked horizontal well large-diameter open-hole packing and acid washing integrated pipe column according to claim 1, characterized in that: The slip inner wall is provided with a through slip groove.

3. The sidetracked horizontal well large-diameter open-hole packing and acid washing integrated pipe column according to claim 1, characterized in that: The rubber cylinder inner wall is provided with a through rubber cylinder groove.

4. The sidetracked horizontal well large-diameter open-hole packing and acid washing integrated pipe column according to claim 1, characterized in that: The filling outer tool comprises a base and a filling sliding sleeve, the filling sliding sleeve is connected to the base through a pin, the base is provided with a door closing step at the upper end, and the base is provided with a filling port.

5. The sidetracked horizontal well large-diameter open-hole packing and acid washing integrated pipe column according to claim 1, characterized in that: The anti-backflow device is a one-way leather cup composite screen structure.

6. The sidetracked horizontal well large-diameter open-hole packing and acid washing integrated pipe column according to claim 1, characterized in that: The pickling sealing device is a V-shaped sealing mode, and the pickling inner sealing device is an interference fit, and when the two are opposite, a seal is formed.

7. The sidetracked horizontal well large-diameter open-hole packing and acid washing integrated pipe column according to claim 1, characterized in that: The filling inner tool is provided with a door closing claw, and when the pipe column is lifted, the door closing claw drives the door closing step on the filling outer tool to close the filling port of the filling outer tool.

8. The sidetracked horizontal well large-diameter open-hole packing and acid washing integrated pipe column according to claim 1, characterized in that: The ball catching device is an elastic net.

Images