Oil well two-layer wheel production mechanical layer change pipe column device

Abstract

The invention discloses a layer changing pipe column device of an oil well two-layer wheel production machine, and belongs to the technical field of oil field production equipment. The oil well two-layer wheel production mechanical layer changing pipe column device comprises an inner pipe column, an outer sleeve pipe column, a ratchet wheel switch mechanism, a flow channel switching cylinder and a sealing plug. When the ratchet wheel switching mechanism pushes the flow channel switching cylinder to move to a preset position, the sealing plug makes contact with and seals the liquid inlet, and a first flow channel path is conducted. And when the ratchet wheel switching mechanism pulls the flow channel switching cylinder to leave a preset position, the sealing plug unseals the liquid inlet, and a second flow channel path is switched and conducted. The oil well two-layer wheel production mechanical layer changing pipe column device is simple in structure, convenient and fast to operate and low in fault risk.

Description

Technical Field

[0001] This application belongs to the technical field of oilfield production equipment, and particularly relates to a mechanical layer-changing string device for two-layer alternate production of oil wells. Background Art

[0002] In the middle and late stages of oilfield development, many oilfields face problems such as low recovery degree, high comprehensive water cut, and high natural decline rate, among which the proportion of low-yield wells is relatively high. Usually, the production method for low-yield wells is alternate production, that is, alternate production between two sets of formations. Thus, when one set of formations is being produced, the other set of formations can be shut in, enabling the formation to recover to a certain extent, which helps to obtain higher production, better economic benefits, and also reduces the risk of phenomena such as water channeling that damage the producing formation.

[0003] The alternate production of oilfields mainly adopts the oil-casing separate production mode, which has a complex structure and inconvenient switching operation. Especially during multiple alternate productions, problems such as pipe-casing structure failure and jamming are extremely likely to occur, affecting the operation efficiency of alternate production. Summary of the Invention

[0004] This application provides a mechanical layer-changing string device for two-layer alternate production of oil wells, aiming to at least solve to a certain extent the technical problems of complex structure, inconvenient switching operation, and easy occurrence of failure and jamming in oilfield alternate production. For this purpose,

[0005] A mechanical layer-changing string device for two-layer alternate production of oil wells provided by an embodiment of this application includes: an inner string, an outer string, a ratchet switch mechanism, a flow path switching cylinder, and a sealing plug;

[0006] The lumen of the inner string is successively divided into a joint cavity, a liquid discharge cavity, a switching control cavity, and a flow path switching cavity by a first partition, a second partition, and a third partition arranged along the axial direction;

[0007] A liquid discharge hole is formed in the first partition, and the liquid discharge hole is provided with a detachable sealing element, so as to compress the sealing element to block the liquid discharge hole when control fluid is injected into the joint cavity;

[0008] The outer string is sleeved outside the inner string to form an annulus flow path, and the annulus flow path is axially divided into a first flow path and a second flow path. The first end of the outer string is sealed and isolated from the outer wall of the inner string;

[0009] A first through hole, a second through hole, and a third through hole are successively formed in the inner string along the axial direction. The first through hole communicates the liquid discharge cavity and the first flow path, the second through hole communicates the first flow path and the flow path switching cavity, and the third through hole communicates the second flow path and the flow path switching cavity;

[0010] The ratchet switch mechanism is arranged in the switching control cavity. A pressure guiding pipe is connected to the inner pipe column, communicating the joint cavity and the switching control cavity to introduce the control fluid injected into the joint cavity into the switching control cavity, pressing the ratchet switch mechanism to switch and lock the switch state;

[0011] The flow path switching cylinder is movably arranged in the flow path switching cavity, and the flow path switching cylinder is connected to the ratchet switch mechanism through a connecting rod penetrating through the third partition member, so as to drive the flow path switching cylinder to axially move along the inner pipe column when the ratchet switch mechanism acts;

[0012] One end of the flow path switching cylinder connected to the connecting rod is closed, and the other end is set as a liquid inlet. First switching holes and second switching holes are sequentially arranged on the cylinder body of the flow path switching cylinder along the axial direction of the inner pipe column;

[0013] A first sealing ring member, a second sealing ring member and a third sealing ring member are sequentially arranged between the flow path switching cylinder and the inner wall of the inner pipe column. The first sealing ring member is located between the first switching hole and the second switching hole, and the second sealing ring member and the third sealing ring member are respectively located on both sides of the third through hole;

[0014] The sealing plug is arranged in the flow path switching cavity and is located within the stroke of the liquid inlet;

[0015] Wherein, when the ratchet switch mechanism pushes the flow path switching cylinder to move to a preset position, the sealing plug contacts and seals the liquid inlet, and the second switching hole is in alignment and communication with the third through hole;

[0016] When the ratchet switch mechanism pulls the flow path switching cylinder away from the preset position, the sealing plug unseals the liquid inlet, and the second sealing ring member is located between the second switching hole and the third through hole to seal off the second switching hole and the third through hole.

[0017] In some embodiments, the sealing plug is a frustum-shaped member, and the inner side surface of the liquid inlet is set as a conical surface matching the frustum-shaped member.

[0018] In some embodiments, the sealing plug is connected to the inner wall of the inner pipe column through a plug support.

[0019] In some embodiments, the sealing plug is movably arranged on the plug support, and the moving direction of the sealing plug is the same as the moving direction of the flow path switching cylinder;

[0020] An elastic support member is further abutted between the sealing plug and the plug support to elastically press the sealing plug when the sealing plug is in matching contact and sealing with the liquid inlet.

[0021] In some embodiments, the plug bracket is a plate-shaped member, and a liquid flow through hole is formed in the plate-shaped member.

[0022] In some embodiments, the elastic support member includes a return spring, the return spring is sleeved on the sealing plug, and two ends of the return spring respectively abut against the plug bracket and the sealing plug.

[0023] In some embodiments, the first sealing ring member, the second sealing ring member, and the third sealing ring member are sealing rings, and the first sealing ring member, the second sealing ring member, and the third sealing ring member are sleeved on the flow path switching cylinder.

[0024] In some embodiments, the packer is a soluble valve ball.

[0025] In some embodiments, the ratchet switch mechanism includes: a pressing head, a ratchet button assembly, and a return spring;

[0026] The pressing head, the ratchet button assembly, and the return spring are sequentially stacked on the third partition member, and the pressing head is connected to the connecting rod.

[0027] In some embodiments, the ratchet button assembly includes: an upper ratchet, a lower ratchet, and a locking pin;

[0028] The upper ratchet and the lower ratchet are matched and aligned and sleeved on the connecting rod, and the upper ratchet and the lower ratchet respectively abut against the pressing head and the return spring, so that under the push of the pressing head, the lower ratchet is driven to axially move and rotate by the upper ratchet, and is locked on the inner pipe column or unlocked and reset from the locking pin on the inner pipe column.

[0029] The embodiments of the present application at least have the following beneficial effects:

[0030] The oil well two-layer cyclic production mechanical layer-changing pipe string device provided by the embodiment of the present application constructs the basic structure for flow path switching with a nested inner pipe string and an outer sleeve pipe string, and specifically divides the inner pipe string into a joint cavity, a liquid drainage cavity, a switching control cavity and a flow path switching cavity in sequence through a first partition, a second partition and a third partition; a liquid drainage hole is formed in the first partition, and a detachable packer is arranged on the liquid drainage hole; the outer sleeve pipe string is sleeved outside the inner pipe string to form an annulus flow path, and the annulus flow path is axially divided into a first flow path and a second flow path, and the gap between the first end of the outer sleeve pipe string and the outer wall of the inner pipe string is sealed; a first through hole, a second through hole and a third through hole are axially formed in sequence on the inner pipe string, the first through hole communicates the liquid drainage cavity and the first flow path, the second through hole communicates the first flow path and the flow path switching cavity, and the third through hole communicates the second flow path and the flow path switching cavity; the ratchet switch mechanism is arranged in the switching control cavity, and a pressure guiding pipe is connected to the inner pipe string to communicate the joint cavity and the switching control cavity; the flow path switching cylinder is movably arranged in the flow path switching cavity, and the flow path switching cylinder is connected with the ratchet switch mechanism through a connecting rod penetrating through the third partition; one end of the flow path switching cylinder connected with the connecting rod is closed, and the other end is set as a liquid inlet, and a first switching hole and a second switching hole are sequentially arranged on the barrel body of the flow path switching cylinder along the axial direction of the inner pipe string; a first sealing ring member, a second sealing ring member and a third sealing ring member are sequentially arranged between the flow path switching cylinder and the inner wall of the inner pipe string, the first sealing ring member is located between the first switching hole and the second switching hole, and the second sealing ring member and the third sealing ring member are respectively located on both sides of the third through hole; the sealing plug is arranged in the flow path switching cavity and is located within the stroke of the liquid inlet.Therefore, when it is necessary to switch the flow path, a sealing element can be arranged in the joint cavity. Under the action of the control fluid, the drain hole on the first sealing element is tightly sealed, so that the control fluid can enter the switching control cavity from the pressure guiding pipe, thereby pressing the ratchet switch mechanism to act, switching the switch state and maintaining the switched state. The flow path switching cylinder descends to cooperate with the sealing plug to seal the liquid inlet. At the same time, the sealing element is removed and the third through hole is aligned with the second switching hole, so that the second flow path, the third through hole, the second switching hole, the flow path switching cylinder cavity, the first switching hole, the second through hole, the first flow path, the first through hole, the drain cavity and the drain interface conduct the first drain flow path; or, drive the ratchet switch mechanism to act, prompt the flow path switching cylinder to reset, seal the liquid inlet based on the contact seal with the sealing plug, open the liquid inlet, use the second sealing ring to seal the second switching hole and the third through hole, cut off the first drain flow path, and conduct the liquid inlet, the flow path switching cylinder cavity, the first switching hole, the second through hole, the first flow path, the first through hole, the drain cavity and the drain interface to conduct the second drain flow path, thereby completing the flow path switching. Therefore, it can be realized according to needs that the flow path is switched and maintained within two casing structures. The structure is simple, and the flow path switching can be realized only by controlling the injection of the fluid. The operation is convenient, and each structural component is within the casing, which can greatly reduce external interference, ensure the stability of the function, and has a relatively low failure rate. Therefore, as a whole, it has the characteristics of simple structure, convenient operation, low failure risk, and high structural function stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 Shows the structural schematic diagram of the mechanical layer-changing pipe string device for two-layer alternate production in an oil well in the embodiment of the present application;

[0033] Figure 2 Shows Figure 1 the A-A cross-sectional view in

[0034] Reference numerals:

[0035] 100 - Inner pipe string, 111 - First separator, 111a - Drain hole, 112 - Second separator, 113 - Third packer, 114 - Plug support, 114a - Liquid flow through hole, 121 - Joint cavity, 121a - Packer, 122 - Drainage cavity, 123 - Switch control cavity, 124 - Flow path switching cavity, 124a - Upper flow turning cavity, 124b - Lower liquid inlet cavity, 131 - First through hole, 132 - Second through hole, 133 - Third through hole, 140 - Pressure guiding pipe;

[0036] 200 - Outer sleeve pipe string, 210 - Annular flow path, 211 - First flow path, 212 - Second flow path, 213 - Separator plate;

[0037] 300 - Ratchet switch mechanism, 310 - Pressing head, 320 - Ratchet key assembly, 321 - Upper ratchet, 322 - Lower ratchet, 322a - Bayonet, 323 - Locking pin, 330 - Return spring;

[0038] 400 - Flow path switching cylinder, 410 - Connecting rod, 420 - Liquid inlet, 431 - First switching hole, 432 - Second switching hole, 441 - First sealing ring part, 442 - Second sealing ring part, 443 - Third sealing ring part, 450 - Flow path switching cylinder cavity;

[0039] 500 - Sealing plug, 510 - Elastic support, 510a - Return spring, 521 - Conical frustum, 522 - Support rod. Detailed implementation mode

[0040] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0041] In addition, the present application may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or arrangements discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0042] Next, the present application will be described in conjunction with the accompanying drawings and with reference to specific embodiments:

[0043] In the oil well rotation production operation, the oil-casing separate production mode is mostly adopted, which requires setting up complex pipeline structures, isolation structures, etc. in the well to implement production independently, or setting up switching operation structures to realize closing and opening of corresponding flow channels, which makes the overall operation inconvenient; and once set up, when a fault maintenance occurs, it is very easy to affect the stability of the structure, and there is a risk of fault jamming and falling apart.

[0044] To this end, an embodiment of the present application provides a two-layer rotation production mechanical layer-changing tubing device for an oil well, which aims to simplify the flow channel switching structure and the rotation production flow channel switching operation to a certain extent, and reduce the risks of failure and jamming.

[0045] See also Figure 1 and Figure 2 In some embodiments, a two-layer rotation production mechanical layer-changing tubular string device for an oil well includes: an inner tubular string 100, an outer tubular string 200, a ratchet switch mechanism 300, a flow channel switching cylinder 400 and a sealing plug 500.

[0046] The inner pipe string 100 and the outer pipe string 200 can be configured as a tubular member, having a pipe body and an internal lumen; and the inner pipe string 100 is embedded in the outer pipe string 200, forming an annular flow channel 210 therebetween. Generally speaking, the inner pipe string 100 and the outer pipe string 200 can be coaxially arranged to form a uniform annular flow channel 210, thereby improving the fluid passability and uniformity.

[0047] The first partition 111, the second partition 112 and the third partition 113 are sequentially arranged along the axial direction in the lumen of the inner tubular column 100 to divide the lumen into sections; specifically, it can be sequentially divided into a joint chamber 121, a drainage chamber 122, a switching control chamber 123 and a flow channel switching chamber 124. The joint chamber 121 is provided with a single-side opening, and the end pipe opening of the inner tubular column 100 can be used as the single-side opening of the joint chamber 121 to connect to the upstream control tubular column to receive the injected control fluid. Alternatively, the upstream oil pipe can be connected to discharge the produced oil.

[0048] Accordingly, a drainage hole 111a is provided on the first partition 111 to connect the drainage cavity 122 and the joint cavity 121, and the drainage hole 111a is provided with a detachable sealing member 121a so that when the control fluid is injected into the joint cavity 121, the sealing member 121a is pressed to seal the drainage hole 111a.

[0049] A partition plate 213 is arranged in the annulus flow channel 210 and is respectively connected to the outer wall of the inner pipe string 100 and the inner wall of the outer casing string 200, so as to axially divide the annulus flow channel 210 into an independent first flow channel 211 and a second flow channel 212. The gap between the first end of the outer casing string 200 and the outer wall of the inner pipe string 100 is sealed, so that the first flow channel 211 is a sealed annular cavity, and one end of the second flow channel 212 can communicate with the downstream pipe string equipment and serve as a part of the oil production output flow channel.

[0050] A first through hole 131, a second through hole 132 and a third through hole 133 are successively arranged on the inner pipe string 100 along the axial direction. The first through hole 131 communicates the liquid discharge cavity 122 and the first flow channel 211, the second through hole 132 communicates the first flow channel 211 and the flow channel switching cavity 124, and the third through hole 133 communicates the second flow channel 212 and the flow channel switching cavity 124, so as to form a stable flow channel structure of the joint cavity 121, the liquid discharge hole 111a, the liquid discharge cavity 122, the first through hole 131, the first flow channel 211, the second through hole 132 and the flow channel switching cavity 124.

[0051] The ratchet switch mechanism 300 adopts a structure based on the conventional ratchet button switch principle, which can realize the switching of the switch state by pressing, and maintain the current on state and off state, and can simultaneously push and move a certain displacement amount in the pressing direction, or reset in the reverse direction of the pressing direction and move a certain displacement amount; thus, the ratchet switch mechanism 300 can be used to push an object to move a certain distance and maintain the position after pushing, and can be pressed again to release the lock and leave space for the object to reset.

[0052] That is, the ratchet switch mechanism 300 can be arranged in the switching control cavity 123, and a pressure guiding pipe 140 is connected to the inner pipe string 100 to communicate the joint cavity 121 and the switching control cavity 123; so as to introduce the control fluid injected into the joint cavity 121 into the switching control cavity 123, press the ratchet switch mechanism 300 to act, and switch and lock the switch state. Generally, a certain space is left at the pressing end of the ratchet switch mechanism 300 to accommodate the control fluid, which is convenient for stably pushing and pressing the ratchet switch mechanism 300.

[0053] They are cooperatively configured. The flow path switching cylinder 400 is movably disposed within the flow path switching cavity 124, and the flow path switching cylinder 400 is connected to the ratchet switch mechanism 300 through a connecting rod 410 passing through the third partition member 113, so as to pull the flow path switching cylinder 400 to move axially along the inner pipe string 100 when the ratchet switch mechanism 300 operates; that is, the ratchet switch mechanism 300 can push and top the flow path switching cylinder 400 to reciprocate in a fixed direction within the flow path switching cavity and maintain the current position after moving in place.

[0054] The flow path switching cylinder 400 can be used as a core component to realize the flow path switching between two round oil production layers, and two flow paths are switched on and conducted through its movement. Specifically, in order to realize the flow path switching, one end of the flow path switching cylinder 400 connected to the connecting rod 410 can be closed, and the other end is set as a liquid inlet 420. First switching holes 431 and second switching holes 432 are sequentially arranged along the axial direction of the inner pipe string 100 on the cylinder body of the flow path switching cylinder 400; a first sealing ring member 441, a second sealing ring member 442, and a third sealing ring member 443 are sequentially arranged between the flow path switching cylinder 400 and the inner wall of the inner pipe string 100, and the first sealing ring member 441 is located between the first switching hole 431 and the second switching hole 432, and the second sealing ring member 442 and the third sealing ring member 443 are respectively located on both sides of the third through hole 133; the sealing plug 500 is disposed within the flow path switching cavity 124 and is located within the stroke of the liquid inlet 420.

[0055] Taking the position where the flow path switching cylinder 400 contacts and seals the liquid inlet 420 with the sealing plug 500 as a preset position as an example, the flow path switching process is described.

[0056] When the ratchet switch mechanism 300 pushes and tops the flow path switching cylinder 400 to move to the preset position, the sealing plug 500 contacts and seals the liquid inlet 420, and the second switching hole 432 is aligned and communicated with the third through hole 133. Thus, the flow path of the second flow path 212, the third through hole 133, the second switching hole 432, the inner cavity of the flow path switching cylinder, that is, the flow path switching cylinder cavity 450, the first switching hole 431, and the flow path switching cavity 140 is conducted, and further sequentially communicated with the second through hole 132, the first flow path 211, the first through hole 131, and the drain cavity 122; the control fluid can be withdrawn to release the pressure on the packer 121a, so that under the impact of the discharged oil fluid, the drain hole 111a is opened, and the first drain flow path is conducted to output the oil fluid to the upstream pipe string.

[0057] Alternatively, when the ratchet switch mechanism 300 pulls the flow path switching cylinder 400 away from the preset position for reset, the sealing plug 500 unseals the liquid inlet 420, and the second sealing ring 442 is located between the second switching hole 432 and the third through hole 133 to seal off the second switching hole 432 and the third through hole 133, thereby disconnecting the conduction state between the flow path switching cylinder 400 and the second flow path 212, and conducting the pipe string below the liquid inlet 420, the liquid inlet 420, the flow path switching cylinder cavity 450, the first switching hole 431, the second through hole 132, the first flow path 211, the first through hole 131, the first liquid discharge cavity 122. By evacuating the control fluid, the pressure on the sealing member 121a can be released, so that under the impact of the discharged oil, the liquid discharge hole 111a is opened, the second liquid discharge flow path is conducted, and the oil is conducted to the upstream pipe string.

[0058] Generally, the first sealing ring 441, the second sealing ring 442, and the third sealing ring 443 cooperate with the inner pipe string 100 and the flow path switching cylinder 400 to strictly divide the flow path switching cavity 124 into two chambers, namely the upper flow chamber 124a and the lower liquid inlet chamber 124b. The upper flow chamber 124a communicates with the second through hole 132 and the first switching hole 431, and the lower liquid inlet chamber 124b communicates with the downstream oil pipe string.

[0059] In some embodiments, to improve the reliability of contact sealing, the sealing plug 500 can be set as a frustum-shaped part, and the inner side surface of the liquid inlet 420 is set as a conical surface matching the frustum-shaped part; thus, when in contact sealing, a larger contact sealing area is provided to improve the sealing reliability.

[0060] In some embodiments, the sealing plug 500 can be connected to the inner wall of the inner pipe string 100 through a plug support 114; it should be noted that the plug support 114 should have gaps that can allow oil to pass through and enter the liquid inlet 420.

[0061] Generally, the plug support 114 can be set as a plate member, and liquid flow through holes 114a can be opened to facilitate the passage of oil.

[0062] In some embodiments, to improve the sealing reliability of the liquid inlet 420, the sealing plug 500 is movably arranged on the plug support 114, and the moving direction of the sealing plug 500 is the same as that of the flow path switching cylinder 400; an elastic support member 510 can also be abutted between the sealing plug 500 and the plug support 114, so that when the sealing plug 500 is in mating contact sealing with the liquid inlet 420, the sealing plug 500 is elastically pressed, thereby maintaining an adaptive elastic pressing ability through the elastic support frame 510 and maintaining the reliability of the seal.

[0063] In some embodiments, the elastic support member 510 may include a return spring 510a, the return spring 510a is sleeved on the sealing plug 500, and both ends of the return spring 510a are respectively abutted on the plug support 114 and the sealing plug 500.

[0064] Generally, the sealing plug can be set to have a frustum 521 and a lower support rod 522, the support rod 522 is movably arranged on the plug support 114 along the axial direction of the inner pipe column 100, and both ends of the return spring are respectively abutted on the bottom of the frustum 521 and the plug support 114.

[0065] In some embodiments, to improve the sealing reliability, the first sealing ring member 441, the second sealing ring member 442, and the third sealing ring member 443 can be set as sealing rings, the first sealing ring member 441, the second sealing ring member 442, and the third sealing ring member 443 are sleeved on the flow path switching cylinder 400, and can slide relative to the inner wall of the inner pipe column 100 together with the flow path switching cylinder 400, maintaining the stability of the position of the sliding seal.

[0066] Correspondingly, the first sealing ring member 441 and the second sealing ring member 442 can be stably arranged on both sides of the second switching hole 432, and the third sealing ring member 443 is located between the liquid inlet 420 and the third through hole 133, maintaining the sealing isolation between the two.

[0067] Considering that there are two states of alignment conduction and sealing isolation between the second switching hole 432 and the third through hole 133, the position of the second sealing ring member 442 can be set accordingly. When the flow path switching cylinder 400 moves to the state of sealing the liquid inlet 420, the second sealing ring member 442 and the third sealing ring member 443 are on the same side of the third through hole 133, and the third through hole 133 is in alignment conduction with the second switching hole 432; relatively, when the liquid inlet is opened, the second sealing ring member 442 and the third sealing ring member 443 are on both sides of the third through hole 133.

[0068] In some embodiments, the seal member 121a seals the drain hole 111a only when controlling the operation of the ratchet switch mechanism 300. During normal oil production, the seal member 121a is removed, and generally, the control fluid can be withdrawn.

[0069] However, in order to improve the operation efficiency, the seal member 121a can be set as a soluble valve ball, which can automatically dissolve after the control fluid is injected for a certain time to release the drain hole 111a. Generally speaking, the operation process of the ratchet switch mechanism 300 is relatively rapid, and the dissolution time of the soluble valve ball is much longer than the operation time, which can meet the time requirement for sealing and opening the drain hole 111a and maintain the smoothness of the cooperation with the control operation of the ratchet switch mechanism 300.

[0070] In some embodiments, the ratchet switch mechanism 300 can be a classic ratchet button switch principle structure, which may include: a pressing head 310, a ratchet button assembly 320, and a return spring 330.

[0071] The pressing head 310, the ratchet button assembly 320, and the return spring 330 are stacked on the third partition member 113 in sequence. The pressing head 310 is connected to the connecting rod 410. By pressing the pressing head 310, such as the pressure of the control fluid, the ratchet button assembly 320 operates to adjust their cooperation posture and maintain it, that is, the ratchet button assembly 320 is in the ejected or reset state, so as to cooperate with pushing the connecting rod 410 and the flow path switching cylinder 400 to move or reset.

[0072] The return spring 330 is used to elastically push the ratchet button assembly 320 to reset.

[0073] Generally speaking, the pressing head 310 can be slidably connected to the inner wall of the inner pipe string 100 to obtain a stable liquid pushing pressure.

[0074] In some embodiments, the ratchet button assembly 320 can adopt a typical upper and lower ratchet structure, which may include: an upper ratchet 321, a lower ratchet 322, and a locking pin 323; the upper ratchet 321 and the lower ratchet 322 are matched and sleeved on the connecting rod 410, and the upper ratchet 321 and the lower ratchet 322 respectively abut against the pressing head 310 and the return spring 330, so as to drive the lower ratchet 322 to axially move and rotate under the push of the pressing head 310, and be locked on the inner pipe string 100 or unlocked and reset from the locking pin 323 by the locking pin 323 arranged on the inner pipe string 100.

[0075] Two notches 322a with different lengths and adapted to cooperate with the locking pin 323 are formed in the lower ratchet wheel 322. When the lower ratchet wheel 323 rotates, the two notches 322a can alternately engage with the locking pin 323 to lock the position of the connecting rod 410 connected to the lower ratchet wheel 322.

[0076] Certainly, the ratchet button assembly 320 may also adopt a ratchet button structure based on other principles, and no specific limitation is imposed herein.

[0077] The embodiment of the present application has at least the following beneficial effects:

[0078] The mechanical layer-changing string device for two-layer alternate production of oil wells provided by the embodiments of the present application constructs a basic structure for flow channel switching with nested inner string and outer string, and specifically, the inner string is sequentially divided into a joint cavity, a liquid drainage cavity, a switching control cavity, and a flow channel switching cavity by a first separator, a second separator, and a third separator; a liquid drainage hole is formed in the first separator, and the liquid drainage hole is provided with a detachable packer; the outer string is sleeved outside the inner string to form an annulus flow channel, and the annulus flow channel is axially divided into a first flow channel and a second flow channel, and the gap between the first end of the outer string and the outer wall of the inner string is sealed; the inner string is axially provided with a first through hole, a second through hole, and a third through hole in sequence, the first through hole communicates the liquid drainage cavity and the first flow channel, the second through hole communicates the first flow channel and the flow channel switching cavity, and the third through hole communicates the second flow channel and the flow channel switching cavity; the ratchet switch mechanism is arranged in the switching control cavity, and a pressure guiding pipe is connected to the inner string, communicating the joint cavity and the switching control cavity; the flow channel switching cylinder is movably arranged in the flow channel switching cavity, and the flow channel switching cylinder is connected with the ratchet switch mechanism through a connecting rod penetrating through the third separator; one end of the flow channel switching cylinder connected with the connecting rod is closed, and the other end is set as a liquid inlet, and a first switching hole and a second switching hole are sequentially arranged on the cylinder body of the flow channel switching cylinder along the axial direction of the inner string; a first sealing ring member, a second sealing ring member, and a third sealing ring member are sequentially arranged between the flow channel switching cylinder and the inner wall of the inner string, and the first sealing ring member is located between the first switching hole and the second switching hole, and the second sealing ring member and the third sealing ring member are respectively located on both sides of the third through hole; the sealing plug is arranged in the flow channel switching cavity and is located within the stroke of the liquid inlet.Therefore, when it is necessary to switch the flow path, a sealing element can be arranged in the joint cavity, so that under the action of the control fluid, the liquid discharge hole on the first sealing element is tightly sealed, so that the control fluid can enter the switching control cavity from the pressure guiding pipe, so as to press the ratchet switch mechanism to act, switch the switch state and maintain the switched state, so that the flow path switching cylinder descends to cooperate with the sealing plug to seal the liquid inlet. At the same time, the sealing element is removed and the third through hole is aligned with the second switching hole, so that the second flow path, the third through hole, the second switching hole, the flow path switching cylinder cavity, the first switching hole, the second through hole, the first flow path, the first through hole, the liquid discharge cavity and the liquid discharge interface conduct the first liquid discharge flow path; or, drive the ratchet switch mechanism to act, prompt the flow path switching cylinder to reset, contact and seal with the sealing plug based on the contact, open the liquid inlet, use the second sealing ring to seal the second switching hole and the third through hole, cut off the first liquid discharge flow path, and conduct the liquid inlet, the flow path switching cylinder cavity, the first switching hole, the second through hole, the first flow path, the first through hole, the liquid discharge cavity and the liquid discharge interface to conduct the second liquid discharge flow path, so as to complete the flow path switching. Therefore, it is possible to realize and maintain the flow path switching within two sleeve structures according to needs, with a simple structure, and only by injecting the control fluid can the flow path switching be realized, the operation is convenient, and each structural component is within the sleeve, which can greatly reduce external interference, ensure the stability of the function, and the failure rate is relatively low. Therefore, as a whole, it has the characteristics of simple structure, convenient operation, low failure risk, and high structural function stability.

[0079] In this application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include that the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the first feature has a lower horizontal height than the second feature.

[0080] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0081] It should be noted that all directional indications in the embodiments of the present application are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If this specific posture changes, the directional indications will also change accordingly.

[0082] In the present application, unless otherwise clearly defined and limited, the terms "connection", "fixation", etc. shall be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0083] In addition, in the present application, the descriptions such as "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise clearly and specifically defined.

[0084] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0085] In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0086] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. A mechanical layer-changing string device for alternate production of two layers in an oil well, characterized in that, Comprising: Inner pipe string, outer sleeve pipe string, ratchet switch mechanism, flow path switching cylinder and sealing plug; The lumen of the inner pipe string is sequentially divided into a joint cavity, a drainage cavity, a switching control cavity and a flow path switching cavity by a first partition member, a second partition member and a third partition member arranged axially; A drainage hole is formed in the first partition member, and the drainage hole is provided with a detachable sealing member, so as to press the sealing member to block the drainage hole when control fluid is injected into the joint cavity; The outer sleeve pipe string is sleeved outside the inner pipe string to form an annulus flow path, and the annulus flow path is axially divided into a first flow path and a second flow path, and the gap between the first end of the outer sleeve pipe string and the outer wall of the inner pipe string is sealed; A first through hole, a second through hole and a third through hole are sequentially formed in the inner pipe string along the axial direction, the first through hole communicates the drainage cavity and the first flow path, the second through hole communicates the first flow path and the flow path switching cavity, and the third through hole communicates the second flow path and the flow path switching cavity; The ratchet switch mechanism is arranged in the switching control cavity, and a pressure guiding pipe is connected to the inner pipe string, communicating the joint cavity and the switching control cavity, so as to introduce the control fluid injected into the joint cavity into the switching control cavity, and press the ratchet switch mechanism to switch and lock the switch state; The flow path switching cylinder is movably arranged in the flow path switching cavity, and the flow path switching cylinder is connected with the ratchet switch mechanism through a connecting rod penetrating through the third partition member, so as to pull the flow path switching cylinder to move along the axial direction of the inner pipe string when the ratchet switch mechanism acts; One end of the flow path switching cylinder connected with the connecting rod is closed, and the other end is set as a liquid inlet, and a first switching hole and a second switching hole are sequentially arranged on the barrel body of the flow path switching cylinder along the axial direction of the inner pipe string; A first sealing ring member, a second sealing ring member and a third sealing ring member are sequentially arranged between the flow path switching cylinder and the inner wall of the inner pipe string, the first sealing ring member is located between the first switching hole and the second switching hole, and the second sealing ring member and the third sealing ring member are respectively located on both sides of the third through hole; The sealing plug is arranged in the flow path switching cavity and is located within the stroke of the liquid inlet; Wherein, when the ratchet switch mechanism pushes the flow path switching cylinder to move to a preset position, the sealing plug contacts and seals the liquid inlet, and the second switching hole is aligned and communicated with the third through hole; When the ratchet switch mechanism pulls the flow path switching cylinder away from the preset position, the sealing plug unseals the liquid inlet, and the second sealing ring member is located between the second switching hole and the third through hole to isolate the second switching hole and the third through hole.

2. The mechanical layer-changing string device for alternate production of two layers in an oil well according to claim 1, wherein The sealing plug is a conical frustum-shaped member, and the inner side surface of the liquid inlet is set as a conical surface matching the conical frustum-shaped member.

3. The mechanical layer-changing tubing string device for alternate production of two layers in an oil well according to claim 1, wherein The sealing plug is connected to the inner wall of the inner pipe string through a plug support.

4. The mechanical layer-changing string device for alternate production of two layers in an oil well according to claim 3, characterized in that, The sealing plug is movably arranged on the plug support, and the moving direction of the sealing plug is the same as the moving direction of the flow path switching cylinder; An elastic support member is further abutted between the sealing plug and the plug support, so as to elastically compress the sealing plug when the sealing plug is in matching contact sealing with the liquid inlet.

5. The mechanical layer-changing tubing string device for alternate production of two layers in an oil well according to claim 4, characterized in that, The plug support is a plate-shaped member, and a liquid flow through hole is formed in the plate-shaped member.

6. The mechanical layer-changing tubing string device for alternate production of two layers in an oil well according to claim 4, characterized in that, The elastic support member includes a return spring, the return spring is sleeved on the sealing plug, and two ends of the return spring are respectively abutted on the plug support and the sealing plug.

7. The mechanical layer-changing tubing string device for alternate production of two layers in an oil well according to claim 1, characterized in that, The first sealing ring member, the second sealing ring member and the third sealing ring member are sealing rings, and the first sealing ring member, the second sealing ring member and the third sealing ring member are sleeved on the flow path switching cylinder.

8. The mechanical layer-changing tubing string device for alternate production of two layers of an oil well according to claim 1, characterized in that, The packer is a soluble valve ball.

9. The mechanical layer-changing tubing string device for alternate production of two layers in an oil well according to claim 1, characterized in that, The ratchet switch mechanism includes: a pressing head, a ratchet button assembly and a return spring; The pressing head, the ratchet button assembly and the return spring are sequentially stacked on the third partition member, and the pressing head is connected with the connecting rod.

10. The mechanical layer-changing tubing string device for alternate production of two layers of an oil well according to claim 9, characterized in that, The ratchet button assembly includes: an upper ratchet, a lower ratchet and a locking pin; The upper ratchet and the lower ratchet are matched and aligned and sleeved on the connecting rod, and the upper ratchet and the lower ratchet are respectively abutted on the pressing head and the return spring, so as to drive the lower ratchet to axially move and rotate through the upper ratchet under the push of the pressing head, and be locked on the inner pipe string or unlocked and reset from the locking pin through the locking pin on the inner pipe string.

Images