Layered water distributor, layered pulsating water injection system and layered pulsating water injection method

Abstract

The layered water distributor comprises multiple stages of layered water distributors which correspond to water injection layers and are connected between two adjacent oil pipes, packers are arranged between the outer portions of the oil pipes at the upper end and the lower end of each stage of layered water distributor and a sleeve in a sealed mode, and the top end of the oil pipe at the uppermost end is communicated with a ground water injection pipeline. A water injection regulating valve and a flow meter are arranged on the ground water injection pipeline, and the water injection regulating valve and the flow meter are in common electric signal connection with a ground layering controller. The underground layered water injection rate is metered by the ground layered controller and linked with the layered water distributor of the underground target interval, layered alternate pulsating water injection is carried out, interlayer interference factors are overcome, and layered accurate water injection is achieved; additional fluid channeling, gravity fluid channeling and capillary force fluid channeling generated by pulsation type unstable water injection solve the problem of invalid water injection of dominant channels. Oil reservoir pressure field changes generated by layered pulsating water injection expand the water injection sweep efficiency, and the water injection recovery efficiency is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield water injection, and specifically relates to a stratified water distributor. The invention also relates to a stratified pulsating water injection system based on the stratified water distributor. The invention further relates to a water injection method of the stratified pulsating water injection system. Background Art

[0002] The stratified water injection method currently commonly used in oil fields is a stable and continuous water injection method. The stratified water injection volume is adjusted once or more each year, and there are two major pain points that are difficult to overcome. The first is the pain point of inaccurate interlayer interference measurement and adjustment. Under the same pressure system conditions, when adjusting the water injection volume of a certain layer, it is bound to affect the water injection volume of other layers. This interlayer interference phenomenon causes the adjustment of the stratified water injection volume to be unable to achieve the water allocation index required by the geological plan; the second is the pain point of invalid water injection in the dominant channel within the layer. Due to the heterogeneity of vertical deposition within the layer, a dominant channel from the water injection well to the oil production well will be opened in the high permeability part of the oil layer during water injection. The formation of this dominant channel makes it impossible for the medium and low permeability parts of the layer to be affected vertically, forming an invalid water injection cycle. Not only does it cause a large amount of water injection energy consumption, but it even causes the water content of the oil well to rise rapidly and flooding and shutdown. Summary of the invention

[0003] The purpose of the present invention is to provide a water injection method for a stratified pulsating water injection system, which solves the problems of inaccurate inter-layer interference measurement and adjustment and ineffective water injection of dominant channels within a layer in the existing stratified water injection methods.

[0004] Another object of the present invention is to provide a stratified pulsating water injection system based on a stratified water distributor.

[0005] Another object of the present invention is to provide a stratified water distributor.

[0006] The first technical solution adopted by the present invention is: a stratified water distributor, including a working cylinder, an axially extending water-through hole is opened in the thickness of the side wall of the working cylinder, a launching and salvaging unit is mounted on the top of the inner wall of the working cylinder through a shoulder, the bottom end of the launching and salvaging unit is downwardly connected to a monitoring control unit and a water injection valve with an opening at the bottom and a flow channel connected to the water-through hole, an axially extending water inlet channel is opened in the water injection valve, a radially extending water outlet hole connected to the water inlet channel is opened on the side wall of the working cylinder, and a water injection hole is radially opened on the side wall of the working cylinder corresponding to the water outlet hole.

[0007] The first technical solution of the present invention is also characterized in that: The launching and salvaging unit includes a lock wheel shell with a top mounted on the shoulder and a bottom extending to below the shoulder, the top of the lock wheel shell is open and a hollow launching head with the top extending upward is fixedly connected to the opening, a salvaging head with the top extending upward is slidably sleeved in the launching head, a limiting lock block extending downward from the launching head is fixedly connected to the bottom end of the salvaging head, an L-shaped upper locking groove is provided at the bottom end of the limiting lock block, a lock wheel opening is provided at the side wall of the lock wheel shell in the longitudinal direction, a lock wheel with one side protruding outward through the lock wheel opening and resting on the bottom end of the shoulder is rotatably connected in the lock wheel shell, an L-shaped lower locking groove is provided at the top of the lock wheel and is buckled with the upper locking groove, and a torsion spring is fixed on the lock wheel, the other end of which is connected to the inner wall of the lock wheel shell.

[0008] The bottom end of the inner wall of the casting head is provided with a limit groove adapted to the size of the limit lock block, and the outer cover of the fishing head is connected with a spring whose upper end abuts against the top of the inner wall of the casting head and whose lower end abuts against the top of the limit lock block.

[0009] The monitoring and control unit includes a battery cylinder, an oil pressure gauge cylinder, a casing pressure gauge cylinder, a control compartment, a communication compartment and a motor compartment, which are threadedly connected in sequence from top to bottom and internally interconnected. The top of the battery cylinder is sealed and a battery is arranged inside. An oil pressure sensor extending radially outward is fixed in the oil pressure gauge cylinder. An annulus extending upward to the bottom end of the shoulder is formed between the outer wall of the oil pressure gauge cylinder and the outer wall of the battery cylinder and the inner wall of the working cylinder. A casing pressure sensor extending radially outward is fixed in the casing pressure gauge cylinder. The outer wall of the casing pressure gauge cylinder corresponds to the casing pressure sensor along the A casing pressure ring groove is provided in the circumferential direction, and sealing rings are sleeved on the upper and lower ends of the outer wall of the casing pressure measuring cylinder near the casing pressure ring groove. A casing pressure measuring hole is radially provided on the side wall of the working cylinder corresponding to the casing pressure ring groove. A controller is arranged in the control compartment, a communication board with an interface facing outward is arranged in the communication compartment, a motor with an output shaft facing downward is fixed in the motor compartment, the battery, oil pressure sensor, casing pressure sensor, controller, communication board and motor are connected by wires, and sealing rings are connected between the battery tube and the oil pressure measuring cylinder, and between the oil pressure measuring cylinder and the casing pressure measuring cylinder.

[0010] The water injection valve is threadedly connected to the motor compartment and are internally connected to a transmission compartment. The inner wall of the transmission compartment protrudes radially inward to form a shaft sealing body with an axial opening. A shaft sealing cover is fixedly connected to the bottom of the bottom end of the shaft sealing body. A screw rod is coaxially matched in the shaft sealing body. A sealing ring is connected between the screw rod and the shaft sealing body. The top end of the screw rod extends outward and is coaxially fixedly connected to the motor output shaft. The bottom end of the screw rod is a threaded section and passes downward through the shaft sealing cover and extends into the water injection valve.

[0011] The water injection valve includes a valve shell threadedly connected to a transmission bin, an outer wall of the valve shell is circumferentially provided with a water injection ring groove corresponding to the water outlet hole, an outer wall of the valve shell is sleeved with sealing rings at both upper and lower ends near the water injection ring groove, the water injection hole is opened at a position corresponding to the water injection ring groove on the side wall of the working cylinder, a valve core sleeve is fixedly sleeved on the inner wall of the valve shell corresponding to the water outlet hole, the inner end of the water outlet hole passes through the valve core sleeve, a valve stem is coaxially arranged in the valve core sleeve, the top end extends upward and is threadedly connected to the bottom end of the screw rod, a valve core inner sleeve is fixedly sleeved on the outside of the valve stem, the valve stem is slidably matched with the inner wall of the valve core sleeve, a water inlet channel is formed outside the valve stem at a position at the bottom end of the valve core inner sleeve, a water inlet hole is axially opened at the bottom end of the valve stem, the bottom of the valve stem is penetrated downward by the bottom and radially penetrated to the water inlet channel by the top, a guide pin is fixedly connected to the outer side of the bottom end of the valve stem along the radial direction, and a guide groove which slides up and down and cooperates with the guide pin is longitudinally opened at the bottom end of the inner wall of the valve shell.

[0012] A pressure equalizing hole is axially provided in the valve stem, the bottom end of which is connected to the water inlet hole, and the top end of the pressure equalizing hole is radially connected to the valve shell above the valve core outer sleeve.

[0013] The bottom of the valve housing is threadedly connected and the interiors are interconnected with a guide filter cover.

[0014] The second technical solution adopted by the present invention is: a stratified pulsating water injection system based on a stratified water distributor, including a multi-stage stratified water distributor connected between two adjacent oil pipes corresponding to each water injection layer, and seals are sealed between the outside of the oil pipes and the casing at the upper and lower ends of each stage of the stratified water distributor. The top of the uppermost oil pipe is connected to a ground water injection pipeline, and a water injection regulating valve, a flow meter and a pressure gauge are provided on the ground water injection pipeline. The water injection regulating valve, the flow meter and the pressure gauge have a common electrical signal connected to a ground stratified controller.

[0015] The third technical solution adopted by the present invention is: a water injection method of a stratified pulsating water injection system, wherein a ground stratified controller controls the water injection regulating valve to open, the stratified water distributor of the first target water injection layer to open according to a set timing, and the stratified water distributors of the other target water injection layers remain closed, and water from the injection hole is injected into the first target water injection layer through casing perforations. When the water injection volume of the first target water injection layer reaches the geological water injection plan, the ground stratified controller controls the water injection regulating valve to close, and the stratified water distributor of the first target water injection layer is then closed at a fixed time to complete the water injection of the first target water injection layer, and start water injection of the second target water injection layer, and the water injection mode of each target water injection layer is cycled to achieve multi-level stratified pulsating water injection.

[0016] The beneficial effects of the present invention are as follows: the stratified water distributor, stratified pulsating water injection system and method of the present invention, the underground stratified water injection volume is measured by the ground stratified controller and linked with the stratified water distributor of the underground target layer section, and stratified alternating pulsating water injection is performed, which overcomes the interlayer interference factors and realizes stratified precise water injection; the additional crossflow, gravity crossflow and capillary force crossflow generated by the pulsating unstable water injection solve the problem of ineffective water injection in the dominant channel. The reservoir pressure field changes caused by the stratified pulsating water injection of the present invention expand the water injection sweep coefficient and greatly improve the water injection recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the layered pulsating water injection system of the present invention; Figure 2 It is a structural schematic diagram of the stratified water distributor of the present invention; Figure 3 It is a schematic structural diagram of the integral components in the working cylinder of the stratified water distributor of the present invention; Figure 4 yes Figure 2 A partial enlarged schematic diagram of position I in the stratified water distributor of the present invention; Figure 5 yes Figure 2 A partial enlarged schematic diagram of position II in the stratified water distributor of the present invention; Figure 6 yes Figure 2 and Figure 5 AA cross-sectional schematic diagram of the stratified water distributor of the present invention; Figure 7 yes Figure 2 A partial enlarged schematic diagram of position III in the stratified water distributor of the present invention; Figure 8 yes Figure 2 and Figure 7 The BB cross-sectional schematic diagram of the stratified water distributor of the present invention; Fig. 9 It is a structural schematic diagram of the stratified water distributor of the present invention in a valve-closed state; Fig.10 yes Fig. 9 A partial enlarged schematic diagram of position III in the stratified water distributor of the present invention; Fig.11 yes Fig. 9 and Fig.10 The BB cross-sectional schematic diagram of the stratified water distributor of the present invention.

[0018] In the figure, 1. water injection layer, 2. oil pipe, 3. layered water distributor, 4. casing, 5. packer, 6. surface water injection pipeline, 7. water injection regulating valve, 8. flow meter, 9. surface layer controller, 10. pressure gauge; 31. Working cylinder, 32. Water through hole, 33. Shoulder, 34. Water inlet channel, 35. Water outlet, 36. Water injection hole, 37. Lock wheel shell, 38. Casting head, 39. Fishing head, 310. Limit lock block, 311. Upper lock groove, 312. Lock wheel mouth, 313. Lock wheel, 314. Lower lock groove, 315. Torsion spring, 316. Limit groove, 317. Spring, 318. Battery cylinder, 319. Oil pressure measuring cylinder, 320. Casing pressure measuring cylinder, 321. Control compartment, 322. Communication compartment, 323. Motor compartment, 324. Battery, 325. Oil pressure sensor, 326. Annulus, 327. Casing pressure sensor, 328. Casing pressure ring groove, 329. Sealing ring, 330. Casing pressure measuring hole, 331. Controller, 332. Communication board, 333. Motor, 334. Transmission compartment, 335. Shaft seal body, 336. Shaft seal gland, 337. Screw, 338. Valve housing, 339. Water injection ring groove, 340. Valve core outer sleeve, 341. Valve stem, 342. Valve core inner sleeve, 343. Water inlet hole, 344. Guide pin, 345. Guide groove, 346. Pressure equalizing hole, 347. Guide filter cover, 348. Oil pipe connector, 349. Boss. DETAILED DESCRIPTION

[0019] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Example 1 The present invention provides a layered pulsating water injection system, such as Figure 1 As shown, it includes a three-level stratified water distributor 3 connected between two adjacent oil pipes 2 via an oil pipe connector 348 corresponding to each water injection layer 1, and a packer 5 is sealed between the outside of the oil pipe 2 and the casing 4 at the upper and lower ends of each level of the stratified water distributor 3. The top of the uppermost oil pipe 2 is connected to a ground water injection pipeline 6, and a water injection regulating valve 7, a flow meter 8, and a pressure gauge 10 are provided on the ground water injection pipeline 6. The water injection regulating valve 7, the flow meter 8, and the pressure gauge 10 are connected to a ground stratified controller 9 with a common electrical signal.

[0021] During operation, the ground stratified controller 9 controls the water injection regulating valve 7 to open, and the injected water enters the downhole oil pipe 2 through the ground water injection pipeline 6. At this time, only the stratified water distributor 3 of a certain target water injection layer 1 is opened, while the stratified water distributors 3 of other water injection layers 1 are closed. The injected water enters the casing 4 through the water injection holes 36 on the stratified water distributor 3, and then enters the target water injection layer 1 through perforations under the obstruction of the upper and lower end packers 5. The stratified injection state is monitored by the pressure gauge 10. When a certain target water injection layer 1 is injected with water, the pressure of the pressure gauge 10 increases, and the stratified injection amount is measured by the flow meter 8. When the target water injection layer 1 reaches the geological water injection plan, the ground stratified controller 9 controls the water injection regulating valve 7 to close, and the stratified water distributor 3 of the target water injection layer 1 is then closed at a fixed time to complete the injection of water to the target water injection layer 1.

[0022] Example 2 The present invention provides a stratified water distributor 3, such as Figures 1 to 3 As shown, it includes a working cylinder 31, and four water-through holes 32 are axially opened in the thickness of the side wall of the working cylinder 31, and a launching and salvaging unit is mounted on the top of the inner wall of the working cylinder 31 through a shoulder 33. The bottom end of the launching and salvaging unit is downwardly connected to a monitoring control unit and a water injection valve with an opening at the bottom and a flow channel connected to the water-through holes 32 in sequence, and a water inlet channel 34 is axially opened in the water injection valve and passes downward, and two opposite water outlet holes 35 connected to the water inlet channel 34 are radially opened on the side wall of the water injection valve, and water injection holes 36 are radially opened on the side wall of the working cylinder 31 corresponding to each water outlet hole 35.

[0023] During operation, the incoming water in the oil pipe 2 enters the working cylinder 31 through the upper oil pipe connector 348. The units inside the working cylinder 31 are limited by the upper and lower limits of the salvage units. The incoming water enters the bottom of the working cylinder 31 through the water through hole 32. If the monitoring and control unit of the target water injection layer 1 controls the water injection valve to open, the injected water flows out of the water through hole 32 and then returns to the bottom opening of the water injection valve, and then flows through the water inlet channel 34 in the water injection valve to the water outlet hole 35, and finally is injected into the casing 4 through the water injection hole 36.

[0024] Example 3 The present invention provides a stratified water distributor 3, based on Example 2, as Figure 3 and Figure 4 As shown, the launching and salvaging unit preferably includes a lock wheel shell 37, a circle of the outer top of the lock wheel shell 37 protrudes radially outward to form a boss 349, the top of the lock wheel shell 37 is mounted on the shoulder 33 of the working cylinder 31 through the boss 349, and the bottom extends to below the shoulder 33, the top of the lock wheel shell 37 is open, and a hollow launching head 38 extending upward from the top is fixedly connected to the opening, and a salvaging head 39 extending upward from the top is slidably sleeved in the launching head 38, and a plurality of circles of grooves are provided in the axial direction at the top of the salvaging head 39, and a limit lock block 310 extending downward from the launching head 38 is fixedly connected to the bottom end of the salvaging head 39, and a limit groove 316 corresponding to the size of the limit lock block 310 is provided at the bottom end of the inner wall of the launching head 38, and a spring 317 is connected to the outer shell of the salvaging head 39, the upper end of which abuts against the top of the inner wall of the launching head 38 and the lower end abuts against the top of the limit lock block 310. An L-shaped upper locking groove 311 is provided at the bottom end of the limiting locking block 310, and a locking wheel opening 312 is provided on the side wall of the lock wheel shell 37 along the longitudinal direction. A locking wheel 313 is rotatably connected in the lock wheel shell 37, one side of which protrudes outward through the locking wheel opening 312 and rests on the bottom end of the shoulder 33. An L-shaped lower locking groove 314 is provided at the top of the locking wheel 313, and a torsion spring 315 is fixed on the locking wheel 313, the other end of which is connected to the inner wall of the lock wheel shell 37.

[0025] When used for the first time, the working cylinder 31 is connected between two adjacent oil pipes 2 through the oil pipe connector 348 and is aligned with the water injection layer 1 and lowered into the casing 4. The packer 5 is used for isolation, and then the internal units of the working cylinder 31 are lowered in turn from the uppermost oil pipe 2. Each internal unit of the working cylinder 31 is an integral component that is threadedly connected in sequence from top to bottom. The inner diameter of the working cylinder 31 decreases from top to bottom, and the outer diameter of the corresponding internal integral component also decreases. After the integral component is lowered into the corresponding working cylinder 31 through the delivery head 38, the top of the lock wheel shell 37 is mounted on the shoulder 33 of the working cylinder 31 through the boss 349, and the units below are suspended at the bottom of the lock wheel shell 37. When water is injected, the overall assembly may also be impacted and disturbed by the upward water flow. Therefore, a lock wheel 313 is rotatably connected in the lock wheel shell 37. When the overall assembly is lowered, the side of the lock wheel 313 protruding from the lock wheel opening 312 is blocked by the shoulder 33 and rotates slightly counterclockwise. At the same time, it moves slightly upward along the limit groove 316 against the limit lock block 310 and compresses the spring 317. When the lock wheel 313 passes the shoulder 33 downward, the spring 317 recovers and the lock wheel 313 rotates clockwise to recover. After recovery, the upper lock groove 311 is fully engaged with the lower lock groove 314 and the side of the lock wheel 313 protruding from the lock wheel opening 312 is against the bottom end of the shoulder 33, thereby limiting the upward movement of the lock wheel shell 37. When it is necessary to salvage the entire assembly in the working cylinder 31 to export or maintain the data of the monitoring control unit, the top groove of the salvage head 39 is hooked through the wellhead salvage rope, and then the salvage head 39 is lifted up to move it along the launching head 38 to the upper locking groove 311 to disengage from the lower locking groove 314. After disengagement, the locking wheel 313 rotates clockwise under the action of the torsion spring 315 to the side protruding from the locking wheel opening 312 and rotates to the lower part of the locking wheel opening 312, thereby releasing the locking connection between the locking wheel 313 and the bottom end of the shoulder 33, and then the salvage head 39 is continued to be lifted to remove the entire assembly in the working cylinder 31.

[0026] Example 4 The present invention provides a stratified water distributor 3, based on Example 2, as Figure 3 , Figures 5 to 7As shown, the monitoring control unit preferably includes a battery tube 318, an oil pressure gauge tube 319, a casing pressure gauge tube 320, a control compartment 321, a communication compartment 322 and a motor compartment 323, which are threadedly connected in sequence from top to bottom and internally interconnected. The battery tube 318 is sealed at the top and a battery 324 is arranged inside. An oil pressure sensor 325 extending radially outward is fixed in the oil pressure gauge tube 319. An annulus 326 extending upward to the bottom end of the shoulder 33 is formed between the outer wall of the oil pressure gauge tube 319 and the outer wall of the battery tube 318 and the inner wall of the working tube 31. A casing pressure sensor 327 extending radially outward is fixed in the casing pressure gauge tube 320. The outer wall of the casing pressure gauge tube 320 is circumferentially provided with a corresponding casing pressure sensor 327. The outer wall of the casing pressure measuring tube 320 is provided with sealing rings 329 at both ends near the casing pressure ring groove 328, and the side wall of the working tube 31 is provided with casing pressure measuring holes 330 radially corresponding to the casing pressure ring groove 328. A controller 331 is arranged in the control compartment 321, a communication board 332 with an interface facing outward is arranged in the communication compartment 322, and a motor 333 with an output shaft facing downward is fixed in the motor compartment 323. The battery 324, the oil pressure sensor 325, the casing pressure sensor 327, the controller 331, the communication board 332 and the motor 333 are connected by wires, and sealing rings 329 are connected between the battery tube 318 and the oil pressure measuring tube 319, and between the oil pressure measuring tube 319 and the casing pressure measuring tube 320.

[0027] During operation, the injected water entering the working cylinder 31 through the oil pipe 2 enters the water through hole 32, and then enters the annulus 326 outside the battery cylinder 318 and the oil pressure measuring cylinder 319 after passing through the boss 349 and the shoulder 33, and the water pressure in the oil pipe 2 is monitored by the oil pressure sensor 325. The liquid pressure outside the oil pipe 2 is measured by the casing pressure sensor 327 in the casing pressure measuring hole 330 connected to the casing 4. In order to avoid the circumferential direction of the casing pressure sensor 327 and the casing pressure measuring hole 330 being difficult to align when the whole assembly is lowered into the working cylinder 31, the casing pressure ring groove 328 is provided to realize that the casing pressure measuring cylinder 320 can accurately measure the liquid pressure outside the casing pressure measuring hole 330 in any direction. Sealing rings 329 are sleeved on the upper and lower ends of the outer wall of the casing pressure gauge tube 320 near the casing pressure ring groove 328, so as to prevent interference caused by water entering the oil pipe 2, and at the same time avoid the influence of water entering the annulus 326 on the control compartment 321, communication compartment 322 and motor compartment 323 below the casing pressure gauge tube 320. However, sealing rings 329 need to be connected above the sealing ring 329 at the upper end of the casing pressure ring groove 328, that is, between the battery tube 318 and the oil pressure gauge tube 319, and between the oil pressure gauge tube 319 and the casing pressure gauge tube 320, to prevent water from entering the annulus 326 and entering the battery tube 318, the oil pressure gauge tube 319 and the casing pressure gauge tube 320. Further, sealing rings 329 can also be connected between the casing pressure gauge tube 320, the control compartment 321, the communication compartment 322 and the motor compartment 323 to increase the safety factor. The controller 331 is used to issue instructions at regular intervals to start and stop the motor 333 in the same working cylinder 31, thereby controlling the switch of the water injection valve. The controller 331 is also used to collect the water pressure in the oil pipe 2 monitored by the oil pressure sensor 325 and the liquid pressure change in the casing 4 monitored by the casing pressure sensor 327. After the monitoring control unit is salvaged out of the well, it is exported to the outside through the communication board 332 interface, thereby collecting the pressure change during the stratified pulsating water injection process, or checking the sealing condition of the packer 5. In the above process, the battery 324 is used to provide power for electrical components such as the oil pressure sensor 325, the casing pressure sensor 327, the controller 331, the communication board 332, and the motor 333.

[0028] Example 5 The present invention provides a stratified water distributor 3, based on Example 4, as Figure 3 and Figure 7 , Figure 8As shown, the water injection valve and the motor compartment 323 are threadedly connected and are internally interconnected with a transmission compartment 334. When working, water enters the water injection valve. In order to prevent water from entering the motor compartment 323 through the transmission compartment 334 and affecting the motor 333, the inner wall of the transmission compartment 334 protrudes radially inward to form a shaft sealing body 335 with an axial opening. A shaft sealing cover 336 is fixedly connected to the lower bottom end of the shaft sealing body 335. A screw rod 337 is coaxially matched in the shaft sealing body 335. A sealing ring 329 is connected between the screw rod 337 and the shaft sealing body 335. The sealing ring 329 cooperates with the shaft sealing body 335 and the shaft sealing cover 336 to form an effective seal for the high-pressure water in the water injection valve. The top end of the screw rod 337 extends outward and is coaxially fixedly connected to the output shaft of the motor 333. The bottom end of the screw rod 337 is a threaded section and passes downward through the shaft sealing cover 336 to extend into the water injection valve, forming a transmission structure for the motor 333 and the water injection valve switch. The motor 333 rotates and drives the screw rod 337 to drive the water injection valve stem 341 connected to it to move up and down to switch the water injection valve.

[0029] The water injection valve includes a valve housing 338 threadedly connected to the transmission chamber 334, and the bottom end of the valve housing 338 is threadedly connected and the guide filter cover 347 is interconnected internally. The outer wall of the valve housing 338 is provided with a water injection annular groove 339 along the circumferential direction corresponding to the water outlet hole 35, and the outer wall of the valve housing 338 is sleeved with sealing rings 329 near the upper and lower ends of the water injection annular groove 339. The water injection hole 36 is provided at the position of the side wall of the working cylinder 31 corresponding to the water injection annular groove 339, and the inner wall of the valve housing 338 is fixedly sleeved with a valve core sleeve 340 corresponding to the water outlet hole 35. The inner end of the water outlet hole 35 passes through the valve core sleeve 340, and the valve core sleeve 340 is coaxially provided with a valve protruding upward at the top and threadedly connected to the bottom end of the screw rod 337. The valve stem 341 is provided with a valve core inner sleeve 342 that is slidably matched with the inner wall of the valve core outer sleeve 340. The water inlet channel 34 is formed outside the valve stem 341 at the bottom end of the valve core inner sleeve 342. The bottom end of the valve stem 341 is provided with a water inlet hole 343 that penetrates downward from the bottom and penetrates radially to the water inlet channel 34 from the top. The valve stem 341 is provided with a pressure equalizing hole 346 that is connected to the water inlet hole 343 from the bottom end, and the top end of the pressure equalizing hole 346 is radially connected to the valve outer shell 338 above the valve core outer sleeve 340. A guide pin 344 is fixedly connected to the outside of the bottom end of the valve stem 341 in the radial direction. A guide groove 345 that is slidably matched with the guide pin 344 is provided with a guide groove 345 that is slidably matched with the guide pin 344 from top to bottom in the longitudinal direction at the bottom end of the inner wall of the valve outer shell 338.

[0030] During operation, if the injection valve of the target injection layer 1 is opened, the injected water flows out through the water through hole 32, enters the bottom of the valve housing 338 under the guidance and filtration of the conical guide filter cover 347, flows upward to the valve stem 341 and enters the water inlet channel 34 through the water inlet hole 343, then enters the water outlet hole 35 through the water inlet channel 34, and finally injects into the sleeve 4 through the water injection hole 36. In this process, in order to avoid the circumference of the water outlet hole 35 and the water injection hole 36 being difficult to align when the whole assembly is lowered into the working cylinder 31, the water injection ring groove 339 is provided to realize that the water outlet of the water outlet hole 35 can be guided to the water injection hole 36 in any rotation direction of the valve housing 338. The outer wall of the valve housing 338 is sleeved with sealing rings 329 at both ends near the water injection annular groove 339, thereby preventing the water flowing through the water injection annular groove 339 from flowing outward through the gap between the outer wall of the valve housing 338 and the inner wall of the working cylinder 31, and preventing the water at the bottom of the water through hole 32 from flowing upward into the gap between the inner wall of the working cylinder 31 and even into the transmission chamber 334, the motor chamber 323 and the upper chamber when entering the guide filter cover 347. Further, the valve housing 338, the transmission chamber 334 and the motor chamber 323 can also be connected with sealing rings 329 to increase the safety factor. Figures 9 to 11 As shown, if the water injection valve of the target water injection layer 1 needs to be closed, the controller 331 will control the motor 333 to start at a fixed time. After the motor 333 is started, it drives the screw rod 337 to rotate. Since the valve stem 341 can only move up and down under the guidance of the guide pin 344 and the guide groove 345 at its bottom end, the valve stem 341 whose top is threaded with the screw rod 337 moves downward under the rotational force. In this process, due to the high water pressure in the oil pipe 2, the water flow entering the water inlet hole 343 synchronously flows into the valve outer shell 338 above the valve core sleeve 340 through the pressure equalizing hole 346, avoiding the problem of insufficient thrust relying solely on the motor 333. When the valve stem 341 moves downward, the valve core inner sleeve 342 synchronously moves downward along the valve core sleeve 340. When the valve core inner sleeve 342 is completely moved down to cover the water outlet hole 35, the connection between the water inlet channel 34 and the water outlet hole 35 is cut off by the valve core inner sleeve 342, and the water injection valve is closed.

[0031] Example 6 The present invention provides a water injection method for the above-mentioned stratified pulsating water injection system, wherein the ground stratified controller 9 controls the water injection regulating valve 7 to open, and the controller 331 in the first target water injection layer 1 sends a valve opening instruction to the motor 333 in the same working cylinder 31 according to the set timing to control the motor 333 to start, and after the motor 333 starts, the valve core inner sleeve 342 on the valve stem 341 moves upward and separates from the covering water outlet hole 35 through transmission, that is, the water injection valve is opened, and at this time, the stratified water distributors 3 of the other target water injection layers 1 remain closed, and are started in sequence by the controller 331 at a fixed time after their respective set timings are reached. The water injection valve is automatically opened. After the water injection valve is opened, water flows out of the water injection hole 36 through the perforation of the casing 4 to inject water into the first target water injection layer 1. At the same time, whether the water injection is effective can be monitored by whether the pressure of the pressure gauge 10 increases during water injection. When the flow meter 8 detects that the water injection volume of the first target water injection layer 1 reaches the geological water injection plan, the ground stratified controller 9 controls the water injection regulating valve 7 to close, and the stratified water distributor 3 of the target water injection layer 1 is then closed at a fixed time to complete the water injection of the first target water injection layer 1, and start the water injection of the second target water injection layer 1, and cycle the water injection mode of each target water injection layer 1 to achieve multi-level stratified pulsating water injection.

[0032] During the water injection process, the controller 331 is also used to collect the water pressure in the oil pipe 2 monitored by the oil pressure sensor 325 and the changes in the injection flow pressure in the casing 4 monitored by the casing pressure sensor 327. After the monitoring control unit is salvaged out of the well, it is exported to the outside through the communication board 332 interface, so as to collect the pressure changes in the layered pulsating water injection process, or to check the sealing condition of the packer 5; when the target layer is closed, the static pressure or pressure recovery of the oil layer can be measured. Through pressure testing, the water injection process of the layer segment can be understood. When the layer segment is closed for a certain period of time, the formation parameters can also be described by pressure.

[0033] Through the above-mentioned manner, the layered pulsating water injection method of the present invention is like the beating of a human pulse. When water is injected into the oil layer from the ground, the formation pressure increases; when the water injection is stopped, the formation pressure decreases. The total time of water injection and water injection stop in each layer is regarded as a pulsation frequency (or a water injection cycle). The number of times water is injected into the oil layer per unit time is the number of water injection pulsations. Such a cycle causes changes in the formation pressure field, and the additional crossflow, gravity crossflow and capillary force crossflow generated solve the problem of ineffective water injection in the dominant channel. According to the additional crossflow theory, the additional crossflow has the characteristic that the direction changes with the change of the periodic water injection method. In the half period of stopping injection or reducing the water injection amount, oil and water cross from the low permeability layer segment to the high permeability layer segment, and in the half period of re-injection or increasing the water injection amount, oil and water cross from the high permeability layer segment to the low permeability layer segment. It is only because of the difference in water saturation between high and low permeability layers that the fluidity changes, causing more water to flow from high-water-content high-permeability layers to low-water-content low-permeability layers, and more oil to flow from low-permeability layers to high-permeability layers in a complete period of time, thereby changing the longitudinal distribution of the longitudinal heterogeneous oil layer formed by the longitudinal balance of gravity and capillary force under stable water injection conditions, making the water drive more uniform, and the additional crossflow generated by pulsating water injection can play a role in regulating the contradictions between layers in the oil layer, improving the water injection sweep coefficient, and activating the oil supply potential of the reservoir.

[0034] The present invention adopts a stratified rotation water injection method. Each water injection layer 1 corresponds to a controller 331. Each time water is injected, a target water injection layer 1 is selected according to a set timing. The controller 331 of the target water injection layer 1 controls the water injection valve to open, and the water injection valves of other water injection layers 1 remain closed. According to the geological stratified water distribution requirements, after the water injection layer 1 is injected, the water injection valve of the water injection layer 1 is closed, and then the water injection valve corresponding to another water injection layer 1 is opened, and so on, to complete the water distribution of each oil layer. In this way, the underground stratified water injection volume is measured by the ground stratified controller 9 and linked with the stratified water distributor 3 of the underground target layer section, which overcomes the interference factors between layers and realizes stratified precise water injection.

[0035] In summary, the reservoir pressure field changes caused by the layered pulsating water injection of the present invention expand the water injection sweep coefficient and greatly improve the water injection recovery rate.

Claims

1. Stratified water distributor, characterized in that: The invention comprises a working cylinder (31), wherein a water-through hole (32) penetrating from top to bottom is axially formed in the thickness of a side wall of the working cylinder (31), a launching and salvaging unit is mounted on the top of the inner wall of the working cylinder (31) via a shoulder (33), the bottom end of the launching and salvaging unit is downwardly connected in sequence to a monitoring control unit and a water injection valve with an opening at the bottom and a flow channel connected to the water-through hole (32), a water inlet channel (34) penetrating downward is axially formed in the water injection valve, a water outlet hole (35) communicating with the water inlet channel (34) is radially formed in the side wall of the water injection valve, and a water injection hole (36) is radially formed on the side wall of the working cylinder (31) corresponding to the water outlet hole (35).

2. The stratified water distributor according to claim 1, characterized in that: The launching and salvaging unit comprises a wheel lock housing (37) whose top is mounted on the shoulder (33) and whose bottom extends to below the shoulder (33); the wheel lock housing (37) has an opening at the top and a hollow launching head (38) extending upward from the top is fixedly connected in the opening; a salvaging head (39) extending upward from the top is slidably sleeved in the launching head (38); a limit lock block (310) extending downward from the launching head (38) is fixedly connected at the bottom end of the salvaging head (39); the bottom of the limit lock block (310) is An L-shaped upper locking groove (311) is formed at the end, a locking wheel opening (312) is formed on the side wall of the locking wheel housing (37) in the longitudinal direction, a locking wheel (313) is rotatably connected in the locking wheel housing (37) and protrudes outward through the locking wheel opening (312) and abuts against the bottom end of the shoulder (33), an L-shaped lower locking groove (314) is formed at the top end of the locking wheel (313) and is buckled with the upper locking groove (311), and a torsion spring (315) is fixed on the locking wheel (313) and the other end of the torsion spring is connected to the inner wall of the locking wheel housing (37).

3. The stratified water distributor according to claim 2, characterized in that: The bottom end of the inner wall of the delivery head (38) is provided with a limit groove (316) of a size adapted to the limit lock block (310), and the outer cover of the fishing head (39) is provided with a spring (317) whose upper end abuts against the top of the inner wall of the delivery head (38) and whose lower end abuts against the top of the limit lock block (310).

4. The stratified water distributor according to claim 1, characterized in that: The monitoring control unit comprises a battery cylinder (318), an oil pressure measuring cylinder (319), a casing pressure measuring cylinder (320), a control chamber (321), a communication chamber (322) and a motor chamber (323) which are threadedly connected in sequence from top to bottom and internally interconnected. The battery cylinder (318) is sealed at the top and a battery (324) is arranged inside. An oil pressure sensor (325) extending radially outward is fixed inside the oil pressure measuring cylinder (319). An annulus (326) extending upward to the bottom end of the shoulder (33) is formed between the outer wall of the oil pressure measuring cylinder (319) and the outer wall of the battery cylinder (318) and the inner wall of the working cylinder (31). A casing pressure sensor (327) extending radially outward is fixed inside the casing pressure measuring cylinder (320). A casing pressure ring groove (325) is circumferentially formed on the outer wall of the casing pressure measuring cylinder (320) corresponding to the casing pressure sensor (327). 8), the outer wall of the casing pressure measuring tube (320) is sleeved with sealing rings (329) at both upper and lower ends near the casing pressure ring groove (328), the side wall of the working tube (31) is radially provided with a casing pressure measuring hole (330) corresponding to the casing pressure ring groove (328), a controller (331) is arranged in the control compartment (321), a communication board (332) with an interface facing outward is arranged in the communication compartment (322), a motor (333) with an output shaft facing downward is fixed in the motor compartment (323), the battery (324), the oil pressure sensor (325), the casing pressure sensor (327), the controller (331), the communication board (332), and the motor (333) are connected by wires, and sealing rings (329) are connected between the battery tube (318) and the oil pressure measuring tube (319), and between the oil pressure measuring tube (319) and the casing pressure measuring tube (320).

5. The stratified water distributor according to claim 4, characterized in that: The water injection valve is threadedly connected to the motor compartment (323) and is internally interconnected with a transmission compartment (334). The inner wall of the transmission compartment (334) protrudes radially inward to form a shaft seal body (335) with an axial opening. A shaft seal gland (336) is fixedly connected below the bottom end of the shaft seal body (335). A screw rod (337) is coaxially matched inside the shaft seal body (335). A sealing ring (329) is connected between the screw rod (337) and the shaft seal body (335). The top end of the screw rod (337) protrudes outward and is coaxially fixedly connected to the output shaft of the motor (333). The bottom end of the screw rod (337) is a threaded section and passes downward through the shaft seal gland (336) to extend into the water injection valve.

6. The stratified water distributor according to claim 5, characterized in that: The water injection valve comprises a valve housing (338) threadedly connected to the transmission chamber (334); an outer wall of the valve housing (338) is provided with a water injection annular groove (339) along the circumferential direction corresponding to the water outlet hole (35); the outer wall of the valve housing (338) is sleeved with sealing rings (329) at both upper and lower ends near the water injection annular groove (339); the water injection hole (36) is provided at a position of the side wall of the working cylinder (31) corresponding to the water injection annular groove (339); a valve core sleeve (340) is fixedly sleeved on the inner wall of the valve housing (338) corresponding to the water outlet hole (35); the inner end of the water outlet hole (35) passes through the valve core sleeve (340); and the valve core sleeve (340) is coaxially provided with a top end extending upward. A valve stem (341) is provided on the bottom end of the screw rod (337) and is threadedly connected to the bottom end of the screw rod (337). A valve core inner sleeve (342) is fixedly sleeved on the outside of the valve stem (341) and is slidably matched with the inner wall of the valve core outer sleeve (340). A water inlet channel (34) is formed on the outside of the valve stem (341) and is located at the bottom end of the valve core inner sleeve (342). A water inlet hole (343) is axially formed at the bottom end of the valve stem (341) and is passed through from the bottom to the bottom and passed through from the top to the water inlet channel (34) in a radial direction. A guide pin (344) is fixedly connected to the outside of the bottom end of the valve stem (341) in a radial direction. A guide groove (345) is longitudinally formed at the bottom end of the inner wall of the valve housing (338) and is slidably matched with the guide pin (344) in an upward and downward direction.

7. The stratified water distributor according to claim 6, characterized in that: The valve stem (341) is provided with a pressure equalizing hole (346) along the axial direction, the bottom end of which is connected to the water inlet hole (343), and the top end of the pressure equalizing hole (346) is connected to the valve housing (338) above the valve core sleeve (340) along the radial direction.

8. The stratified water distributor according to claim 6, characterized in that: A guide filter cover (347) is threadedly connected below the bottom end of the valve housing (338) and is internally interconnected.

9. The stratified pulsating water injection system based on the stratified water distributor according to claim 1 is characterized in that: The invention comprises a multi-stage stratified water distributor (3) connected between two adjacent oil pipes (2) corresponding to each water injection layer (1), a packer (5) being sealed between the outer side of the oil pipe (2) and the casing (4) at the upper and lower ends of each stage of the stratified water distributor (3), the top of the uppermost oil pipe (2) being connected to a surface water injection pipeline (6), a water injection regulating valve (7), a flow meter (8) and a pressure gauge (10) being arranged on the surface water injection pipeline (6), and the water injection regulating valve (7), the flow meter (8) and the pressure gauge (10) being connected to a surface stratified controller (9) through a common electrical signal.

10. The water injection method of the stratified pulsating water injection system according to claim 9, characterized in that: The surface layered controller (9) controls the water injection regulating valve (7) to open, the layered water distributor (3) of the first target water injection layer (1) to open according to a set time sequence, the layered water distributors (3) of the other target water injection layers (1) remain closed, and water from the water injection hole (36) is injected into the first target water injection layer (1) through the perforation of the casing (4). When the injection volume of the first target water injection layer (1) reaches the geological water injection plan, the surface layered controller (9) controls the water injection regulating valve (7) to close, and the layered water distributor (3) of the first target water injection layer (1) is then closed at a fixed time, completing the injection of the first target water injection layer (1), and starting the injection of the second target water injection layer (1), and cyclically injecting each target water injection layer (1) to achieve multi-stage layered pulsating water injection.

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