Well flushing valve and oil sleeve separate injection tubular column capable of backwashing well

Abstract

The utility model relates to the field of borehole flushing equipment in oil exploitation work, in particular to a well flushing valve and an oil sleeve separate injection pipe column capable of backwashing a well. An interlayer annulus is formed between an inner pipe and an outer pipe of the well flushing valve, a water inlet hole is formed in the lower end of the outer pipe, a well flushing hole is formed in the lower end of the inner pipe, and a ball seat is arranged in an inner cavity of the upper end of the inner pipe; a pressurizing hole and a pressure relief hole are formed in the inner pipe above and below the ball seat respectively, a sealing ring is arranged on the upper side of the interlayer annulus, a sealing pipe is arranged on the lower side of the interlayer annulus close to the well washing hole, and a pressing type reversing mechanism is arranged between the sealing ring and the sealing pipe so as to drive the sealing pipe to move downwards in the downward moving process of the sealing ring. A spring providing elastic force upwards is further arranged at the bottom of the sealing pipe so as to push the sealing pipe and the sealing ring to move upwards during pressure relief, and the position of the sealing pipe is switched so that the water inlet hole and the well washing hole can be disconnected or communicated. According to the scheme, the problems that in the prior art, large pressure needs to be applied during inverse well flushing, safety and reliability are not enough, and construction cost is high are solved.

Description

Technical Field

[0001] This utility model relates to the field of equipment for flushing wellbores in oil extraction operations, and particularly to a well-washing valve and a reverse-washing oil casing injection string. Background Technology

[0002] As oilfield development progresses into its later stages, and casing service life increases, the number of wells with casing damage rises. Suspending small casing (four-inch casing) within the well can quickly and economically address this issue. Currently, separate water injection for oil and casing is a common method used in various oilfields, particularly suitable for wells with suspended small casing. However, long-term water injection in these wells inevitably leads to the deposition of scale and impurities on the packer in the annulus, which can clog oil reservoir channels and even affect tubing maintenance. Therefore, regular well cleaning is necessary. Wells with suspended small casing, such as... Figure 1 As shown, this well has the characteristics of a large inner diameter in the upper casing and a small inner diameter in the suspended tailpipe. If the well is flushed in the forward direction, the flushing fluid returns quickly in the small casing, which can quickly flush out impurities. However, when it enters the large casing, the flow area increases and the flow velocity decreases, making it difficult to carry out mechanical impurities such as mechanical particles and solid particles. In some cases, they may even deposit on the packer, causing the tubing string to get stuck. Therefore, wells with suspended small casing are not suitable for flushing in the forward direction and can only be flushed in the reverse direction.

[0003] For example, the oil casing injection well washing valve disclosed in Chinese utility model patent with authorization announcement number CN213743304U, the inner shaft of the tool including the trajectory tube can be regarded as a push-type reversing mechanism. Through the movement of the push-type reversing mechanism, the bypass hole and the outlet hole are connected or disconnected, so as to realize the well washing or closing of the well washing valve. When a cleaning operation is required, the activation ball is inserted. The activation ball is made of special nylon material and can plastically deform after withstanding hydraulic pressure greater than 10 MPa. Water is injected by starting the pump. When the activation ball falls into the inclined surface on the ball seat inside the tool, the pump pressure increases significantly. Under the action of hydraulic pressure, the entire inner shaft of the tool moves downward. At this time, the spring is compressed and energy is stored. The reversing pin moves upward along the long track relative to the reversing groove. Under the guidance of the ratchet inclined surface above the reversing groove, the entire inner shaft of the tool rotates. The reversing pin aligns with the short track. After continuing to pressurize to more than 10 MPa, the activation ball deforms through the inner shaft of the tool and finally falls into the bottom of the tubing string. The pressure inside the well-washing valve drops sharply. The spring causes the inner shaft of the tool to move upward, and the reversing pin falls into the short track. At this time, the bypass hole and the outlet hole are connected, and the tool is activated. Forward and reverse well washing can be performed as needed.

[0004] The present scheme can realize backwashing, but the problem is that the power of the reversing pin switching track is derived from the hydraulic pressure above the activation ball, and in order to make the tool guide the well, the tool inner shaft needs to be depressurized, and the track pipe is lifted by the spring to make the reversing pin enter the long track, but the premise of tool depressurization is to continuously pressurize the activation ball, and the activation ball can be plastically deformed and fall and depressurize only when the hydraulic pressure exceeds 10MPA, that is, a larger pressure needs to be applied to guide the well working pump, which is not safe and reliable and has high construction cost. Practical new type content

[0005] The utility model discloses a well washing valve, to solve the problem of not safe and reliable and high construction cost caused by the larger pressure needed in the prior art backwashing, and the utility model discloses a kind of oil jacket separate injection pipe column of backwashing, to solve the above problems.

[0006] To achieve the above object, a well washing valve in the utility model adopts the following technical scheme:

[0007] A well washing valve, comprising upper and lower connectors, an inner tube and an outer tube coaxially arranged are connected between the upper and lower connectors, and a sandwich annulus is formed between the two, the lower end of the outer tube is provided with a water inlet hole, the lower end of the inner tube is provided with a well washing hole communicating with the inner cavity of the inner tube and the sandwich annulus near the water inlet hole, the inner cavity of the upper end of the inner tube is provided with a ball seat, at least one pressurizing hole and a pressure relief hole are respectively provided above and below the ball seat, a sealing ring sealing the pressure relief hole is provided on the lower side of the pressurizing hole on the upper side of the sandwich annulus, to be moved downward under the pressure of liquid entering the sandwich annulus from the pressurizing hole after the ball seat is blocked by ball, until the sealing ring moves downward to guide the pressurizing hole and the pressure relief hole to realize pressure relief, a sealing tube is provided near the well washing hole on the lower side of the sandwich annulus, a pressing reversing mechanism is provided between the sealing ring and the sealing tube, to drive the sealing tube to move downward during the movement of the sealing ring, and a spring providing elastic force upward is further provided at the bottom of the sealing tube, to push the sealing tube and the sealing ring to move upward when depressurizing, and switch the position of the sealing tube to disconnect or guide the water inlet hole and the well washing hole.

[0008] The above technical scheme has the following beneficial effects:

[0009] The utility model discloses a kind of well flushing valves, when the well flushing valve needs to switch to the working state of reverse well flushing, valve ball is put into ball seat, inner tube inner chamber is blocked, liquid flow is from pressurizing hole into interlayer annulus, hydraulic pressure acts on the top of sealing ring, under the force transmission of press type reversing mechanism, sealing pipe constantly compresses bottom spring, with the increasing of liquid flow pressure, when sealing ring moves to certain position downwards, pressure relief hole is exposed and is communicated with pressurizing hole, liquid flow is from pressure relief hole into inner tube inner chamber and makes interlayer annulus above sealing ring pressure relief, at this time, under the action of bottom spring and press type reversing mechanism, sealing pipe returns to certain height, so that water inlet hole on outer tube and well flushing hole on inner tube are communicated, realize reverse well flushing;If you want to switch to normal water injection state, valve ball is still in ball seat, inner tube inner chamber is blocked, liquid flow is from pressurizing hole into interlayer annulus, hydraulic pressure acts on the top of sealing ring, under the force transmission of press type reversing mechanism, sealing pipe constantly compresses bottom spring, with the increasing of liquid flow pressure, when sealing ring moves to certain position downwards, pressure relief hole is exposed and is communicated with pressurizing hole, liquid flow is from pressure relief hole into inner tube inner chamber and makes interlayer annulus above sealing ring pressure relief, at this time, under the action of bottom spring and press type reversing mechanism, the height of sealing pipe return is lower than the height when reverse well flushing, so that water inlet hole on outer tube and well flushing hole on inner tube are disconnected, after a period of time, valve ball is dissolved and becomes smaller and falls into well, and normal water injection is restored.The present scheme sets up pressure relief hole to release pressure, only needs to press to make sealing ring slide to certain distance, when pressure relief hole and pressurizing hole are communicated, it can release pressure, compared with the prior art that more than 10MPA pressure is applied to make active ball fall and release pressure, the required pressure is smaller, and then construction cost is lower, and it is more safe and reliable.

[0010] Further, the sealing pipe blocks the well flushing hole and / or the water inlet hole to block the water inlet hole and the well flushing hole.

[0011] Further, the sealing pipe includes a pipe body, and an annular step is protruded from a lower end of the pipe body, the spring is sleeved outside the annular step and abuts against the lower end of the pipe body.

[0012] Further, the spring abuts against a lower end surface of the sealing pipe.

[0013] Further, a channel is arranged on the pipe body to make the well flushing hole and the water inlet hole communicated.

[0014] Further, the pressing type reversing mechanism comprises a thrust tube coaxially arranged in the interlayer annulus, a steering ring and a diameter expansion section on the inner tube, the bottom of the thrust tube is provided with a sawtooth structure, the inner wall of the steering ring is provided with a guide rib, the diameter expansion section is arranged between the pressure relief hole and the well flushing hole on the inner tube, the bottom of the diameter expansion section is provided with a ratchet groove, a rectangular groove is arranged between every two ratchet grooves in the axial direction, the guide rib can slide along the groove wall when located in the ratchet groove or the rectangular groove, the bottom of the steering ring abuts against the sealing tube, the top of the guide rib cooperates with the sawtooth structure and the bottom of the guide rib is upwardly pressed by the spring so that the guide rib reverses between the rectangular groove and the ratchet groove.

[0015] Further, the tubular sliding sleeve is arranged above the thrust tube, and the bottom of the sliding sleeve is provided with a ring groove matched with the thrust tube.

[0016] Further, the guide rib is in a long strip structure with an inclined surface arranged at the top.

[0017] Further, a plurality of guide ribs are arranged along the inner wall of the steering ring.

[0018] To achieve the above object, the oil casing separate injection pipe column capable of back flushing well in the utility model adopts the following technical scheme:

[0019] An oil casing separate injection pipe column capable of back flushing well, comprising a tubing, a casing and a well flushing valve installed on the tubing, the well flushing valve comprises upper and lower joints, the coaxially arranged inner tube and outer tube are connected between the upper and lower joints, and an interlayer annulus is formed between the inner tube and the outer tube, the lower end of the outer tube is provided with a water inlet hole, the lower end of the inner tube is provided with a well flushing hole near the water inlet hole, the inner cavity of the upper end of the inner tube is provided with a ball seat, the inner tube is provided with at least one pressurizing hole and a pressure relief hole above and below the ball seat respectively, the interlayer annulus is provided with a sealing ring below the pressurizing hole and above the pressure relief hole, so that the sealing ring moves downward under the pressure of the liquid entering the interlayer annulus from the pressurizing hole after the ball seat is blocked by the ball, until the sealing ring moves downward to guide the pressurizing hole and the pressure relief hole to realize pressure relief, the sealing tube is arranged near the well flushing hole at the lower side of the interlayer annulus, the pressing type reversing mechanism is arranged between the sealing ring and the sealing tube, so as to drive the sealing tube to move downward during the movement of the sealing ring, the spring is further arranged at the bottom of the sealing tube to provide elastic force upwardly, so as to push the sealing tube and the sealing ring to move upwardly during pressure relief, and switch the position of the sealing tube to disconnect or connect the water inlet hole and the well flushing hole.

[0020] The above technical scheme has the following beneficial effects:

[0021] The utility model discloses a kind of oil casing separate injection pipe columns that can backwash well, the well washing valve of this pipe column is arranged pressurizing hole and pressure relief hole on the pipe wall of inner tube located above and below ball seat, when well washing valve needs to switch to the working state of backwash well, valve ball is put into ball seat, inner tube inner chamber is blocked, liquid flow is from pressurizing hole into interlayer annulus, hydraulic pressure acts on the top of sealing ring, under the force transmission of press type reversing mechanism, sealing pipe constantly compresses bottom spring, with the increasing of liquid flow pressure, when sealing ring moves to certain position downwards, pressure relief hole is exposed and is communicated with pressurizing hole, liquid flow is from pressure relief hole into inner tube inner chamber and makes interlayer annulus above sealing ring pressure relief, at this time, under the action of bottom spring and press type reversing mechanism, sealing pipe returns to certain height, so that water inlet hole on outer tube and well washing hole on inner tube are communicated, backwash well is realized;If it is switched to normal water injection state, valve ball is still in ball seat at this time, inner tube inner chamber is blocked, liquid flow is from pressurizing hole into interlayer annulus, hydraulic pressure acts on the top of sealing ring, under the force transmission of press type reversing mechanism, sealing pipe constantly compresses bottom spring, with the increasing of liquid flow pressure, when sealing ring moves to certain position downwards, pressure relief hole is exposed and is communicated with pressurizing hole, liquid flow is from pressure relief hole into inner tube inner chamber and makes interlayer annulus above sealing ring pressure relief, at this time, under the action of bottom spring and press type reversing mechanism, the height of sealing pipe returning is lower than the height when backwash well, so that water inlet hole on outer tube and well washing hole on inner tube are disconnected, after a period of time, valve ball is dissolved and becomes smaller and falls into well, and normal water injection is restored. The present scheme sets pressure relief hole to release pressure, only needs to pressurize to make sealing ring slide to certain distance, when pressure relief hole and pressurizing hole are communicated, it can release pressure, compared with the prior art that more than 10MPA pressure is applied to make active ball fall and release pressure, the required pressure is smaller, and then construction cost is lower, and it is safer and more reliable.

[0022] Further, the sealing pipe blocks the well washing hole and / or the water inlet hole to block the water inlet hole and the well washing hole.

[0023] Further, the sealing pipe includes a pipe body, and an annular step is protruded on the lower end of the pipe body, and the spring is sleeved outside the annular step and abuts against the lower end of the pipe body.

[0024] Further, the spring abuts against the lower end surface of the sealing pipe.

[0025] Further, a channel is arranged on the pipe body to make the well washing hole and the water inlet hole communicated.

[0026] Furthermore, the push-type reversing mechanism includes a thrust tube, a steering ring, and an enlarged diameter section on the inner tube, all coaxially arranged in the interlayer annulus. The bottom of the thrust tube has a serrated structure, and the inner wall of the steering ring is provided with guide ribs. The enlarged diameter section is located between the pressure relief hole and the well cleaning hole on the inner tube. The bottom of the enlarged diameter section is provided with ratchet grooves, and a rectangular groove is provided axially between every two ratchet grooves. The guide ribs are located in the ratchet grooves or rectangular grooves and can slide along the groove wall. The bottom of the steering ring abuts against the sealing tube, and the top of the guide ribs cooperates with the serrated structure and the bottom is pressed upward by a spring to make the guide ribs reverse direction between the rectangular grooves and the ratchet grooves.

[0027] Furthermore, a tubular sliding sleeve is provided above the thrust tube, and an annular groove that mates with the thrust tube is provided at the bottom of the sliding sleeve.

[0028] Furthermore, the guide rib is a long strip structure with a sloping surface at the top.

[0029] Furthermore, multiple guide ribs are provided along the inner wall of the steering ring. Attached Figure Description

[0030] Figure 1 Here is a schematic diagram of the structure of the oil casing injection string of this utility model applied to backwashing wells;

[0031] Figure 2 Here is a schematic diagram of the well-washing valve in its normal water injection state according to this utility model;

[0032] Figure 3 for: Figure 2 Cross-sectional view at point A;

[0033] Figure 4 Here is a schematic diagram of the well-washing valve in the backwashing state of this utility model;

[0034] Figure 5 for: Figure 4 Cross-sectional view at point A;

[0035] Figure 6 Here is a schematic diagram of the inner tube track unfolding circumferentially in this utility model;

[0036] Figure 7 Here is a partial structural diagram of the inner tube expansion section in this utility model;

[0037] Figure 8 for: Figure 7 Cross-sectional view at point A;

[0038] Figure 9 Here is a schematic diagram of the ratchet structure at the bottom of the jacking pipe in this utility model;

[0039] Figure 10 Here is a bottom view of the jacking pipe in this utility model;

[0040] Figure 11 Figure 1 is a structural schematic view of a steering ring in the utility model;

[0041] Figure 12 Figure 1 is a structural schematic view of a steering ring in the utility model;

[0042] In the drawing: 1, oil pipe; 2, first annular space; 3, well flushing valve; 4, packer; 5, second annular space; 6, horn mouth; 7, casing; 8, upper oil layer; 9, lower oil layer; 31, upper joint; 310, spring; 311, first chamber; 312, second chamber; 313, valve ball; 32, outer pipe; 321, water inlet hole; 33, lower joint; 34, inner pipe; 341, pressurizing hole; 342, pressure relief hole; 343, well flushing hole; 344, diameter expansion section; 3441, rectangular groove; 3442, ratchet groove; 3443, first guide section; 3444, second guide section; 345, ball seat; 35, sealing ring; 36, thrust pipe; 361, sawtooth structure; 362, limiting structure; 37, steering ring; 371, guide rib; 38, sealing pipe; 39, sealing ring; 40, pipe body; 401, passage; 402, annular step; 41, sliding sleeve. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the utility model more clear and explicit, the following will be further detailed in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model, and are not used to limit the utility model, that is, the described examples are only a part of the examples of the utility model, but not all the examples. The components of the utility model embodiments described and shown in the drawings herein can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the claimed utility model, but only represents selected embodiments of the utility model. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the utility model.

[0045] A basic example of a well flushing valve in the utility model:

[0046] As Figure 2As shown, the well washing valve 3 comprises upper and lower connectors, between which an inner tube 34 and an outer tube 32 are coaxially arranged to form an interlayer annulus, i.e. the inner side of the upper connector 31 is connected with the upper end of the inner tube 34, and the outer side of the upper connector 31 is connected with the outer tube 32; similarly, the inner side of the lower connector 33 is connected with the lower end of the inner tube 34, and the outer side of the lower connector 33 is connected with the outer tube 32. The lower end of the outer tube 32 is provided with a water inlet hole 321 which communicates the interlayer annulus with the annular space between the oil pipe 1 and the casing 7, and the lower end of the inner tube 34 is provided with a well washing hole 343 which communicates the inner cavity of the inner tube 34 with the interlayer annulus near the water inlet hole 321, and the inner tube 34 is provided with a ball seat 345 near the upper end of the inner cavity of the inner tube 34, and the inner tube 34 is provided with a pressurizing hole 341 and a pressure relief hole 342 which respectively communicate the inner cavity of the inner tube 34 with the interlayer annulus on the upper and lower tube walls of the inner tube 34 above and below the ball seat 345, i.e. the pressurizing hole 341 is arranged on the upper tube wall of the inner tube 34 above the ball seat 345, and the pressure relief hole 342 is arranged on the lower tube wall of the inner tube 34 below the ball seat 345. The upper side of the interlayer annulus is provided with a sealing ring 35 which seals the pressure relief hole 342, and the sealing ring is provided with upper and lower sealing rings on the joint surfaces which respectively contact the inner tube 34 and the outer tube 32, and when the inner tube is blocked by a ball, the liquid entering the interlayer annulus from the pressurizing hole acts on the sealing ring 35 to make the sealing ring 35 move downward until the sealing ring 35 moves downward to expose the pressure relief hole 342, thereby conducting the pressurizing hole 341 and the pressure relief hole 342 to achieve pressure relief. The lower side of the interlayer annulus is provided with a sealing tube 38 near the well washing hole 343, the upper part of the interlayer annulus of the sealing ring 35 is a first chamber 311, the lower part of the interlayer annulus of the sealing tube 38 is a second chamber 312, and a pressing type reversing mechanism is arranged between the sealing ring 35 and the sealing tube 38 to drive the sealing tube 38 to move downward together during the downward movement of the sealing ring 35, and the bottom of the sealing tube 38 is further provided with a spring 310 which provides elastic force upward, and when the pressure relief hole 342 is relieved, the spring 310 pushes the sealing tube 38 and the sealing ring 35 to move upward to switch the position of the sealing tube 38 to disconnect or conduct the water inlet hole 321 and the well washing hole 343.

[0047] Specifically, the pressing type reversing mechanism is similar to the automatic pen pressing type reversing structure disclosed in the Taiwan Utility Model Patent No. TWM296793U.

[0048] Specifically, as Figures 1-4As shown, the upper and lower joints are threadedly connected with the inner tube 34 and the outer tube 32. The upper and lower ends of the inner tube 34 are provided with threads, the upper and lower ends of the outer tube 32 are provided with internal threads, the upper and lower ends of the upper joint 31 are provided with internal threads, the internal threads of the upper end of the upper joint 31 are threadedly connected with the oil pipe 1, the internal threads inside the lower end of the upper joint 31 are threadedly connected with the inner tube 34, and the outer threads outside the lower end of the upper joint 31 are threadedly connected with the outer tube 32, so as to realize the fixed connection of the upper joint 31 with the upper end of the outer tube 32 and the upper end of the inner tube 34 to block the first chamber 311, and the cooperation with the oil pipe 1; similarly, the upper and lower ends of the lower joint 33 are provided with internal threads, the internal threads of the lower end of the lower joint 33 are threadedly connected with the oil pipe 1, the internal threads inside the upper end of the lower joint 33 are threadedly connected with the inner tube 34, and the outer threads outside the upper end of the lower joint 33 are threadedly connected with the outer tube 32, so as to realize the fixed connection of the lower joint 33 with the lower end of the outer tube 32 and the lower end of the inner tube 34 to block the second chamber 312, and the connection with the oil pipe 1; in other embodiments, the inner tube 34 is integrally formed with the upper joint 31, the outer tube 32 is integrally formed with the lower joint 33, the lower end of the inner tube 34 is threadedly connected with the lower joint 33, and the upper end of the outer tube 32 is inserted into the upper joint 31.

[0049] In other embodiments, in order to better realize the liquid inlet pressurization and liquid outlet pressure relief of the first chamber 311, two or three pressurization holes 341 and pressure relief holes 342 are arranged.

[0050] On the basis of the above-mentioned embodiments, in a preferred embodiment, as shown in Figure 2 or Figure 4 the sealing section of the sealing tube 38 is long enough to block the water inlet hole 321 and the well flushing hole 343 at the same time, and at this time the sealing tube 38 blocks the well flushing hole 343 and the water inlet hole 321 to realize the normal water injection of the well flushing valve 3; in other embodiments, the sealing section of the sealing tube 38 is short, and the water inlet hole 321 and the well flushing hole 343 have a large height difference in the axial direction, and the sealing tube 38 blocks the well flushing hole 343 to realize the normal water injection of the well flushing valve 3; in other embodiments, the sealing tube 38 blocks the water inlet hole 321 to realize the normal water injection of the well flushing valve 3.

[0051] On the basis of the above-mentioned embodiments, in a preferred embodiment, in order to better cooperate the bottom of the sealing tube 38 with the elastic member and transmit the compression force from the spring 310, as shown in Figure 2 or Figure 4 the sealing tube 38 comprises a tube body 40, the lower end of the tube body 40 protrudes an annular step 402, and the spring 310 is sleeved outside the annular step 402 and abuts against the lower end of the tube body 40; in other embodiments, the sealing tube 38 no longer has the annular step 402, and the spring 310 directly abuts against the lower end surface of the sealing tube 38.

[0052] On the basis of the above-mentioned embodiments, in a preferred embodiment, as shown in Figure 2 or Figure 4 , a channel 41 is arranged on the pipe body 40, when backwashing, the channel 41 is communicated with the washing well hole 343 and the water inlet hole 321; in other embodiments, the pipe body 40 is not arranged at the bottom of the sealing pipe 38, the length of the sealing pipe 38 is shorter, and the channel 41 is not arranged, when the sealing pipe 38 is moved to be higher than the washing well hole 343, the washing well hole 343 is communicated with the water inlet hole 321.

[0053] On the basis of the above-mentioned embodiments, in a preferred embodiment, as shown in Figures 2-12 , the press-type reversing mechanism includes a push tube 36 and a steering ring 37 arranged coaxially from top to bottom in the interlayer annulus, and a diameter expansion section 344 on the inner tube. The bottom of the push tube 36 has a sawtooth structure 361, the inner wall of the steering ring 37 is provided with a guide rib 371, and the inner tube 34 is provided with a diameter expansion section 344 with a diameter slightly larger than that of the inner tube 34 between the pressure relief hole 342 and the washing well hole 343. The bottom of the diameter expansion section 344 is uniformly provided with a ratchet groove 3442 along the circumferential direction of the tube wall, and a rectangular groove 3441 is arranged axially between every two ratchet grooves 3442, as shown in Figure 6 , the rectangular groove 3441 and the two ratchet grooves 3442 are staggered, and the guide rib 371 can slide in the groove wall to make the steering ring 37 slide along the groove wall when the guide rib 371 is located in the rectangular groove 3441 or the ratchet groove 3442. The bottom of the steering ring 37 is pressed on the sealing pipe 38. When the steering ring 37 is located below the groove under the action of hydraulic pressure, the top of the guide rib 371 cooperates with the sawtooth structure 361, the top of the guide rib 371 slides along the inclined edge of the sawtooth structure 361, and under the pushing action of the bottom spring 310, the steering ring 37 can be turned to realize the switching of the guide rib 371 between the rectangular groove 3441 and the ratchet groove 3442; in other embodiments, the groove is the sliding groove structure described in the authorized announcement No. CN105587289B, the sliding groove is arranged on the diameter expansion section 344 of the inner tube 34 in the circumferential direction, and the first guide part of the sliding groove extends in the axial direction as a “short” groove for normal water injection of the well washing valve 3, and the fifth guide part of the sliding groove extends in the axial direction as a “long” groove for backwashing of the well washing valve 3.

[0054] Specifically, as shown in Figures 9-12 , the bottom of the push tube 36 is provided with a limiting structure 362, which is an inner boss, and the inner boss is arranged in the rectangular groove 3441 of the inner tube 34 to keep the push tube 36 stable and prevent it from rotating relative to the inner tube 34.

[0055] Specifically, as shown in Figures 6-7As shown, the two grooves limit and guide the guide rib 371, when the guide rib 371 changes direction to the rectangular groove 3441, the guide rib 371 slides up a longer distance under the action of the bottom spring 310, that is, the steering ring 37 slides a longer distance, so that the sealing tube 38 moves a longer distance, at this time the well washing hole 343 is in communication with the water inlet hole 321, and the backwashing is realized; when the guide rib 371 changes direction to the ratchet groove 3442, the guide rib 371 slides up a short distance under the action of the bottom spring 310, that is, the steering ring 37 slides a short distance, so that the sealing tube 38 moves a short distance, and the guide rib 371 is clamped at the root of the ratchet groove 3442, the well washing hole 343 is disconnected with the water inlet hole 321, and the well washing valve 3 is closed.

[0056] Specifically, as shown in the drawings, Figure 6 there are a first guide section 3443 and a second guide section 3444 below the two adjacent ratchet grooves 3442.

[0057] On the basis of the above-mentioned embodiments, in a preferred embodiment, if the length of the well washing valve 3 is too long, the axial distance from the pressure relief hole 342 to the expanded section 344 is large, and a sliding sleeve 41 is additionally arranged above the thrust pipe 36 to transmit pressure, as shown in the drawings, Figures 2-4 the sliding sleeve 41 is a tubular structure with sufficient length, the top end of the sliding sleeve 41 abuts against the sealing ring 35, the bottom end of the sliding sleeve 41 abuts against the thrust pipe 36, and the sliding sleeve 41 can slide up and down along the inner pipe 34, and the bottom of the sliding sleeve 41 is further provided with a sliding groove matched with the thrust pipe 36, which is an inner step, and the top of the thrust pipe 36 abuts against the inner step, so as to realize the cooperation between the sliding sleeve 41 and the thrust pipe 36.

[0058] On the basis of the above-mentioned embodiments, in a preferred embodiment, in order to make the guide rib 371 cooperate with the sawtooth structure 361 and facilitate the change of direction, as shown in the drawings, Figure 11 the top of the guide rib 371 has an inclined surface which can cooperate with the sawtooth structure 361, and the top inclined edge of the guide rib 371 slides along the inclined edge of the sawtooth structure 361, so as to realize the change of direction of the steering ring 37, and in order to better limit the guide rib 371 in the sliding groove, the guide rib 371 is a long strip structure; in other embodiments, the guide rib 371 is a short block structure with an inclined surface at the top.

[0059] On the basis of the above-mentioned embodiments, in a preferred embodiment, as shown in the drawings, Figures 11-12 in order to reduce the pressure on the top end of the guide rib 371 when it cooperates with the groove, a plurality of guide ribs 371 are arranged to cooperate with the groove, and three guide ribs 371 are evenly arranged along the inner wall of the steering ring 37; in other embodiments, one or two guide ribs 371 are arranged.

[0060] The utility model discloses an oil casing separate injection pipe column of backwashing well, which comprises a tubing 1 and a well washing valve 3 connected to the tubing 1. Figure 1 As shown in the figure, the packer 4 is arranged on the tubing 1 between the upper oil layer 8 and the lower oil layer 9, the space between the tubing 1 above the packer 4 and the casing 7 is the first annulus 2, the space between the tubing 1 below the packer 4 and the casing 7 is the second annulus 5, the well washing valve 3 is installed in the second annulus 5, the water inlet hole 321 is communicated with the first annulus 2, and the horn mouth 6 is arranged in the second annulus 5 at the tail of the tubing 1.

[0061] The working principle of the oil casing separate injection pipe column backwashing well is as follows: Figure 1 And Figure 2 And Figure 4 As shown in the figure, when backwashing well, the valve ball 313 is put into the tubing 1, the valve ball 313 acts on the ball seat 345, the tubing 1 is pressurized, the inner tube 34 is blocked, the liquid flows to the first chamber 311 through the pressurizing hole 341 of the inner tube 34, and the sealing ring 35, the sliding sleeve 41, the thrust tube 36, the steering ring 37 and the sealing tube 38 are pushed downward until the lower end of the sealing tube 38 abuts against the lower joint 33 through the spring 310, and the sealing tube 38 cannot move downward any more. In the process, the guide ribs 371 of the steering ring 37 move downward along the vertical groove wall of the ratchet groove 3442, and the spring 310 is compressed. When the guide ribs 371 of the steering ring 37 are below the two grooves of the inner tube 34 expansion section 344, the steering ring 37 rotates a certain angle under the guidance of the sawtooth inclined surface of the thrust tube 36, the guide ribs are clamped at the tooth root position of the sawtooth structure, and the sealing ring 35 moves downward in the process, the pressure relief hole 342 is exposed, the first chamber 311 is depressurized, the pressure acting on the front end of the sealing ring 35 disappears, the spring 310 in the compressed state rebounds and elongates, and pushes the steering ring 37 upward. At this time, the guide ribs 371 of the steering ring 37 rotate along the second guide section 3444 at the bottom of the ratchet groove 3442 and change tracks (change direction into the rectangular groove 3441). When the guide ribs 371 of the steering ring 37 change direction into the rectangular groove 3441, the steering ring 37 continues to move upward relative to the rectangular groove 3441 under the action of the spring 310, and slides to the reset position above the rectangular groove 3441. At the same time, the sealing tube 38 slides upward under the action of the spring 310, and at this time, the sealing rings 39 on the sealing tube 38 are all located above the well washing hole 343. At this time, the well washing hole 343 is communicated with the water inlet hole 321, the inner cavity of the inner tube is communicated with the first annulus, the well washing fluid is injected from the casing 7, enters the inner tube 34 along the first annulus 2, the valve ball is lifted to a certain height by the upward well washing fluid but is not washed out of the well washing valve upward, the well washing fluid is washed out of the well washing valve from both sides of the valve ball upward, and the backwashing well is carried out.

[0062] When the well washing is finished and normal water injection is needed, the valve ball originally lifted falls on the ball seat to block the inner pipe, the tubing is again pressed, the hydraulic pressure again enters the first chamber 311 through the pressurizing hole 341, pushes the sealing pipe 38 to slide downward, at this time the rear end of the sealing pipe 38 again abuts against the lower joint 33 through the spring 310, the sealing pipe 38 cannot slide backward any more. At this time, the guide rib 371 of the steering ring 37 moves downward along the rectangular groove 3441 of the inner pipe 34 until the groove, the spring 310 is compressed, the guide rib 371 is guided by the inclined surface of the sawtooth mechanism, the steering ring 37 rotates by a certain angle again, the pressure relief hole 342 is exposed, the front end of the sealing ring 35 is relieved, the steering ring 37 rotates upward under the push of the spring 310, the guide rib 371 rotates along the first guide section 3443 at the bottom of the ratchet groove 3442 and changes track (changes direction into the ratchet groove 3442). Under the limiting action of the ratchet groove 3442, the guide rib 371 can slide upward along the groove wall for a short distance, that is, the steering ring 37 ascends for a short distance, and further the sealing pipe 38 ascends for a limited distance, at this time the well washing hole 343 is located between the sealing rings 39 of the sealing pipe 38, the well washing hole 343 is disconnected with the water inlet hole 321, after a period of time, the valve ball 313 is dissolved to be small and falls into the well, normal water injection can be resumed.

[0063] The above is only a preferred embodiment of the present application, and is not used to limit the present application, the patent protection scope of the present application is subject to the claims, any equivalent structural change made according to the content of the specification and drawings of the present application should be included in the protection scope of the present application.

Claims

1. A well wash valve characterized by, The lower end of the outer tube is provided with a water inlet hole, and the lower end of the inner tube is provided with a well flushing hole near the water inlet hole for connecting the inner cavity of the inner tube with the interlayer annulus.

2. A well wash valve according to claim 1, characterised in that The sealing tube blocks the well flushing hole and / or the water inlet hole to block the water inlet hole and the well flushing hole.

3. A well wash valve according to claim 2, wherein, The sealing tube includes a tube body, and the lower end of the tube body is provided with an annular step.

4. A well wash valve according to claim 2, wherein The spring is pressed against the lower end surface of the sealing tube.

5. A well wash valve according to claim 3, wherein A channel is arranged on the tube body to make the well flushing hole and the water inlet hole communicate.

6. A well wash valve according to claim 1 wherein, The push tube is provided with a sawtooth structure at the bottom, the inner wall of the steering ring is provided with a guide rib, and the expansion section is arranged between the pressure relief hole and the well flushing hole on the inner tube.

7. A well wash valve according to claim 6, wherein The push tube is provided with a tubular sliding sleeve above, and the bottom of the sliding sleeve is provided with a ring groove matched with the push tube.

8. A well wash valve according to claim 7, wherein, The guide rib is a long strip structure with an inclined surface at the top.

9. A well wash valve according to any one of claims 6 to 8, wherein, The guide rib is arranged on the inner wall of the steering ring.

10. A backwashable wellbore tubing string for separate injection of oil and casing, characterized in that, The well flushing valve is arranged on the oil pipe.

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