Oil and gas well multilayer unblocking production integrated tool, equipment and unblocking method

Abstract

The invention relates to the technical field of oil and gas field development engineering, in particular to an oil and gas well multi-layer plug removal production integrated tool, device and method. The oil and gas well multi-layer plug removal production integrated tool comprises an upper connector connected with a related phase, and the upper connector is sequentially connected with a sliding sleeve and a tail pipe plug in a detachable mode; the upper joint is connected with a packer; a plurality of spraying holes are formed in the middle of the sliding sleeve, and a corresponding hydraulic releasing ball is arranged in the sliding sleeve in a matched mode. Fixed-point injection plug removal of plug removal liquid can be achieved, layer-by-layer plug removal is achieved, meanwhile, a production pipe column composed of the remaining upper connector and the oil pipe column can be directly used for production, tripping is not needed to be conducted again, the tool is simple in structure, tripping is not needed to be conducted again, production can be directly conducted, operation is convenient, and production efficiency is improved. Manpower and material resources are greatly saved, the requirement for multi-layer accurate jetting unblocking of an old well is met, and the problems that in the prior art, layer-by-layer unblocking cannot be achieved in the acidification unblocking process, and operation is complex due to the fact that an unblocking tool tripped into the well is complex are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development engineering, and specifically to a tool, equipment and method for oil and gas well multi-layer unblocking production integration, especially a tool, equipment and method for unblocking production integration for multiple reservoirs layer by layer. Background Art

[0002] In the process of tapping the potential and resuming production of old wells in gas fields, old wells and old layers are seriously blocked by sludge, scale, fracturing fluid, etc., and acid deblocking treatment is required. However, in the acid deblocking process, some gas wells have multiple strata distributed in large spans. The conventional method of using the original multi-seal pipe string for general acidizing is easy to cause the deblocking fluid to leak from a single old layer, making it difficult to effectively achieve the purpose of accurately tapping the potential and deblocking multiple strata.

[0003] There are two existing unblocking processes: Method 1: In the early stage, the wellbore is intact and there are no other pipes in the wellbore. The unblocking production integrated pipe string is run in after perforation, and the pressure packer is used to set the seal and drop the ball to open the sliding sleeve for layered unblocking; Method 2: The original well pipe string is pulled out by pressure well, and the layered unblocking tool is re-run for unblocking. The current one-time run of the multi-layer unblocking production integrated pipe string contains multiple hydraulic anchors, packers and other complex tools in the wellbore. It is difficult to pull the pipe string out of the well again. In the later stage, sand flushing, well washing, gas lift, secondary unblocking, etc. are required, which cannot be realized due to the small inner diameter of the pipe string.

[0004] The invention patent with the authorization publication number CN110439510B provides a method for acidification and stratified water injection in water injection wells. An acid injection integrated pipe string is lowered into the casing, which includes a switch valve, an upper water distributor, a packer, a lower water distributor, an intermediate oil pipe, an acidification check valve, a screen pipe, a coating oil pipe and a thread plug from top to bottom; the upper and lower layers are sealed by pressurizing the annulus, and the space inside the pipe string is sealed by throwing soluble balls to remove the blockage in layers. The upper switch valve contains a spring self-sealing device, and the water distributor is opened manually after the blockage is removed. Although the blockage is removed layer by layer, the device only solves the problem of two layers of blockage, and the tools for lowering into the wellbore are complicated, and multiple unblocking cannot be performed directly. The later operation still needs to lift and replace the pipe string again, and the layer-by-layer unblocking of the pipe string cannot be achieved in one operation. Summary of the invention

[0005] In view of the problems in the prior art of being unable to achieve layer-by-layer unblocking during the acid unblocking process and the complicated operation caused by the complexity of the unblocking tools lowered into the well, the present invention provides an integrated tool, equipment and method for multi-layer unblocking production in oil and gas wells.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides an integrated tool for multi-layer unblocking production in oil and gas wells, comprising an upper joint connected to an oil pipe, wherein the upper joint is disassembled and connected with a sliding sleeve and a tail pipe plug in sequence; a packer is connected to the upper joint; a plurality of injection holes are arranged on the sliding sleeve, and a hydraulic release ball is arranged inside the sliding sleeve.

[0008] Preferably, a safety joint is also provided on the upper joint.

[0009] Preferably, the sliding sleeve is connected to the upper joint via a plurality of shear pins.

[0010] Preferably, the shear pins are distributed circumferentially along the sliding sleeve.

[0011] Preferably, the end of the sliding sleeve on the connection side with the upper joint is connected with a conical ring, and the hydraulic hand-release ball is arranged in the conical ring.

[0012] Preferably, the end of the sliding sleeve is threadedly connected to the tail pipe plug.

[0013] Preferably, the sliding sleeve and the hydraulic throwing ball are both made of soluble materials.

[0014] Preferably, the tail pipe plug is made of a soluble material.

[0015] An oil and gas well unblocking device comprises the above-mentioned oil and gas well multi-layer unblocking production integrated tool.

[0016] A multi-layer plugging removal method for oil and gas wells using the above tool comprises the following steps:

[0017] S1: Connect the oil and gas well multi-layer plugging removal and production integrated tool to the oil pipe;

[0018] S2: lower the connected oil and gas well multi-layer plugging removal and production integrated tool into the well;

[0019] S3: Align the injection hole of the oil and gas well multi-layer plugging removal and production integrated tool that is lowered into the well with the layer to be unblocked;

[0020] S4: Pump high-pressure unblocking fluid into the tubing string, open the sliding sleeve, expose the injection hole, set the packer, and unblock the blockage-removing layer;

[0021] S5: After the unblocking is completed, the tubing string is lifted, the packer is unblocked, and the injection hole of the oil and gas well multi-layer unblocking production integrated tool is aligned with the next unblocking layer, and S4 is repeated to unblock the next unblocking layer;

[0022] S6: Repeat S4 and S5 until all the layers to be unblocked are unblocked, and the oil and gas well multi-layer unblocking is completed.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] A multi-layer unblocking production integrated tool for oil and gas wells includes an upper joint connected with relevant parts, wherein the upper joint is sequentially disassembled and connected with a sleeve and a tail pipe plug; a packer is arranged on the upper joint; a plurality of injection holes are arranged on the sleeve, and a hydraulic hand-release ball is arranged inside the sleeve. Through the arrangement of the sleeve, the hydraulic hand-release ball, the packer and the tail pipe plug, the fixed-point injection unblocking of the unblocking liquid can be realized, thereby realizing the multi-layer unblocking of the oil and gas wells layer by layer. At the same time, after the unblocking is completed, the sleeve, the hydraulic hand-release ball and the tail pipe plug can be thrown to the bottom of the artificial well, and the remaining upper joint and the oil pipe string form a production string, which can be directly used for production without repeatedly pulling up and down the drill and lowering the production string again. While realizing the multi-layer unblocking of the oil and gas wells layer by layer, the tool structure is simple, and the production can be directly entered without pulling up and down the drill and lowering the production string again. The operation method is simple, which greatly saves manpower and material resources, meets the needs of multi-layer precise injection unblocking of old wells, and is suitable for vertical wells, directional wells, horizontal wells, etc.

[0025] The upper joint is also provided with a safety joint. When the oil pipe string cannot be lifted, it can be unfastened by rotating to lift the pipe string above the safety joint, so as to facilitate lifting all the pipe strings out of the ground.

[0026] The sliding sleeve and the upper joint are connected by a plurality of shear pins, and the provision of the shear pins can realize the fixation of the sliding sleeve and the upper joint.

[0027] The shear pins are distributed circumferentially along the sliding sleeve to ensure the connection between the upper joint and the sliding sleeve before the rapid shearing is achieved.

[0028] The end of the sliding sleeve connected to the upper joint is connected with a conical ring, and the hydraulic hand-release ball is arranged in the conical ring, which is conducive to the setting of the hydraulic hand-release ball and the fitting of the bottom during pressing.

[0029] The end of the sliding sleeve is threadedly connected to the tail pipe plug, which is convenient for disassembly and installation.

[0030] The sliding sleeve and the hydraulic hand-release ball are both made of soluble materials, and the tail pipe plug is made of soluble material, which can automatically fall off and dissolve after the plugging is unblocked to avoid the sliding sleeve, hydraulic hand-release ball and tail pipe plug being thrown into the artificial well and affecting production.

[0031] The present invention also provides an oil and gas well unblocking device, including the above-mentioned oil and gas well multi-layer unblocking production integrated tool. The device can realize multi-layer and layer-by-layer fixed-point unblocking of oil and gas wells without repeatedly tripping and lowering the production string again. The device is simple and easy to operate.

[0032] The present invention also provides a multi-layer unblocking method for oil and gas wells using the above-mentioned tool, which is as follows: the multi-layer unblocking production integrated tool for oil and gas wells is connected to an oil pipe; the connected multi-layer unblocking production integrated tool for oil and gas wells is lowered into a well; the injection hole of the multi-layer unblocking production integrated tool for oil and gas wells lowered into the well is aligned with the layer to be unblocked; high-pressure unblocking liquid is pumped into the inside of the oil pipe string, the sleeve is opened to expose the injection hole, the packer is set, and the layer to be unblocked is unblocked, after the unblocking is completed, the oil pipe string is lifted, the packer is unsealed, and the injection hole of the multi-layer unblocking production integrated tool for oil and gas wells is aligned with the next layer to be unblocked, and the next layer to be unblocked is unblocked; until all the layers to be unblocked are unblocked, the multi-layer unblocking of the oil and gas well is completed. The method is simple and easy to operate, and realizes multi-layer and layer-by-layer fixed-point unblocking of oil and gas wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of an integrated tool for multi-layer plugging removal and production of oil and gas wells according to the present invention.

[0034] Figure 2 The present invention is a flow chart of a multi-layer unblocking production method for oil and gas wells.

[0035] Among them, 1-upper joint, 2-hydraulic hand ball, 3-shear nail, 4-sliding sleeve, 5-injection hole, 6-tail pipe plug, 7-packer, 8-safety joint. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0039] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0040] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0041] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0043] Example 1

[0044] See also Figure 1 The present invention discloses an integrated tool for multi-layer unblocking production in oil and gas wells, comprising an upper joint 1 connected to an oil pipe, the upper joint 1 being connected to a sleeve 4 and a tail pipe plug 6 in sequence; a packer 7 and a safety joint 8 being connected to the upper joint 1, the safety joint 8 being arranged on the upper joint between the packer 7 and the sleeve 4; a plurality of injection holes 5 being arranged on the side wall of the sleeve 4, a hydraulic release ball 2 being arranged inside the sleeve 4; the packer 7 being a mechanical packer, having the function of pressure differential sealing and lifting the oil pipe to unseal; a hydraulic release device being arranged on the joint 1.

[0045] The sliding sleeve 4 is connected to the upper joint 1 through a plurality of shear pins 3, and the shear pins 3 are distributed circumferentially along the sliding sleeve 4; the end of the connecting side of the sliding sleeve 4 and the upper joint 1 is connected with a conical ring, and the hydraulic hand-release ball 2 is arranged in the conical ring.

[0046] The tail pipe plug 6 is threadedly connected to the end of the sliding sleeve 4 .

[0047] When the integrated tool for multi-layer unblocking production of China National Petroleum Corporation gas wells is in use, the oil pipe string is connected through the upper joint 1, and then the tool is lowered into the well, the injection hole 5 is aimed at the layer that needs to be unblocked, and then high-pressure unblocking liquid is pumped into the oil pipe string for fixed-point spraying unblocking. After one layer is completed, the pipe string is moved to the next layer that needs to be unblocked and the fixed-point spraying unblocking operation is performed again until all layers are completed. After that, the pipe string is lowered to the production depth, and high-pressure liquid is pumped into the oil pipe string by throwing a ball, and the sliding sleeve 4 is released by the hydraulic release device, so that the sliding sleeve 4, the hydraulic release ball 2 and the tail pipe plug 6 fall into the artificial well bottom, that is, the integrated function of multi-layer unblocking production of gas wells is realized.

[0048] Example 2

[0049] See also Figure 1 The present invention discloses an integrated tool for multi-layer plugging removal and production in oil and gas wells, comprising an upper joint 1 connected to a relevant part, wherein the upper joint 1 is connected to a sleeve 4 and a tail pipe plug 6 in sequence; a packer 7 and a safety joint 8 are arranged on the pipe wall of the upper joint 1, wherein the safety joint 8 is arranged on the upper joint between the packer 7 and the sleeve 4; a plurality of injection holes 5 are arranged on the side wall of the sleeve 4, wherein the number of the injection holes 5 is greater than 3, and a hydraulic release ball 2 is arranged inside the sleeve 4; the sleeve 4 is connected to the upper joint 1 through a plurality of shear pins 3, wherein the shear pins 3 are circumferentially distributed along the sleeve 4; a conical ring is connected to the end of the sleeve 4 on the side connected to the upper joint 1, wherein the hydraulic release ball 2 is arranged inside the conical ring. The tail pipe plug 6 is threadedly connected to the end of the sleeve 4; the sleeve 4, the hydraulic release ball 2 and the tail pipe plug 6 are all made of soluble materials; the packer 7 is a mechanical packer that can be repeatedly used by pressing and setting and lifting and releasing.

[0050] When the integrated tool for multi-layer plugging removal and production of Sinopec gas wells is used, the oil pipe string is connected through the upper joint 1, and then it is lowered into the well, the injection hole 5 is aimed at the layer that needs to be unblocked, and then high-pressure unblocking liquid is pumped into the oil pipe string for fixed-point injection unblocking. After one layer is completed, the pipe string is moved to the next layer that needs to be unblocked and the fixed-point injection unblocking operation is performed again until all layers are completed. The pipe string is lowered to the production depth, and the sliding sleeve 4, the hydraulic hand-release ball 2 and the tail pipe plug 6 are dissolved and automatically fall off and fall to the bottom of the well, thereby realizing the integrated function of multi-layer plugging removal and production of gas wells.

[0051] The integrated tool for multi-layer unblocking production of oil and gas wells provided in Examples 1 and 2 can also, after multi-layer unblocking, connect a functional packer below the safety joint 8 and above the unblocking tool string, i.e., the sleeve 4. The functional packer can be sealed to the inner wall of the casing by holding pressure, and the oil pipe can be lifted to unseal. During the operation, a sealing bridge plug with an aperture is lowered into the tubing string below the functional packer. After the bridge plug is sealed, a soluble ball is put into the tubing string to block the aperture of the bridge plug, and then unblocking liquid is injected to hold pressure to seal the functional packer. When the wellhead pressure drop is 0, the soluble ball dissolves, and the layer to be unblocked is unblocked. After the target layer is unblocked, the oil pipe is lifted and the functional packer is unsealed. This cycle is repeated to achieve multiple unblocking in sequence.

[0052] The present invention provides an oil and gas well unblocking device, including the above-mentioned oil and gas well multi-layer unblocking production integrated tool. The device can realize multi-layer and layer-by-layer fixed-point unblocking of oil and gas wells without repeatedly tripping and lowering the production string again. The device is simple and easy to operate.

[0053] The present invention also provides a multi-layer plugging removal method for oil and gas wells using the above-mentioned tool, comprising the following steps:

[0054] S1: Connect the oil and gas well multi-layer plugging removal and production integrated tool to the oil pipe;

[0055] S2: lower the connected oil and gas well multi-layer plugging removal and production integrated tool into the well;

[0056] S3: Align the injection hole 5 of the oil and gas well multi-layer unblocking production integrated tool lowered into the well with the layer to be unblocked;

[0057] S4: Pump high-pressure unblocking liquid into the tubing string, open the sliding sleeve 4, expose the injection hole 5, and set the packer 7 to unblock the layer to be unblocked;

[0058] S5: After the unblocking is completed, the oil pipe string is lifted, the packer 7 is unblocked, and the injection hole 5 of the oil and gas well multi-layer unblocking production integrated tool is aligned with the next unblocking layer, and S4 is repeated to unblock the next unblocking layer;

[0059] S6: Repeat S4 and S5 until all the layers to be unblocked are unblocked, and the oil and gas well multi-layer unblocking is completed.

[0060] After the multi-layer unblocking of the oil and gas well is completed, the pipe string is lowered to the production depth, and the hydraulic release ball 2 is put into the conical ring at the end of the sliding sleeve 4, and high-pressure liquid is pumped into the oil pipe string to release the sliding sleeve 4, so that the sliding sleeve 4, the hydraulic release ball 2 and the tail pipe plug 6 fall to the bottom of the artificial well, realizing the integrated function of multi-layer unblocking and production of the gas well.

[0061] If unblocking operations are needed again in the future, the tubing string is lowered into the upper part of the unblocking reservoir, and a hydraulic throw-away ball 2 is lowered into the tubing string. The hydraulic throw-away ball 2 is a soluble ball. The ball is thrown to pressurize and seal the mechanical controllable packer. After the ball dissolves, acid is injected to unblock. After unblocking, the tubing string is lifted up, and the multi-layer unblocking operations are completed in sequence.

[0062] In summary, the present invention provides an integrated tool, equipment and method for multi-layer unblocking production of oil and gas wells. By designing an integrated oil and gas well multi-layer unblocking production tool, it can not only realize multi-layer layered unblocking, but also realize the production and reuse of oil pipe strings, ensuring that after unblocking, the pipe string in the wellbore is simple, which is conducive to the subsequent layer inspection and hole filling, gas lift, sand flushing, well repair, secondary unblocking and other operations. The structure is simple and easy to operate, and it is an advanced technology in the field of oil and gas field development engineering technology.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and substitutions, and these modifications and substitutions are also within the scope of protection covered by the claims.

Claims

1. An integrated tool for multi-layer plugging removal and production in oil and gas wells, characterized in that: The utility model comprises an upper joint (1) connected to an oil pipe, wherein the upper joint (1) is sequentially disassembled and connected with a sliding sleeve (4) and a tail pipe plug (6); a packer (7) is connected to the upper joint (1); a plurality of injection holes (5) are arranged on the sliding sleeve (4), and a hydraulic release ball (2) is arranged inside the sliding sleeve (4).

2. The oil and gas well multi-layer plugging removal and production integrated tool according to claim 1, characterized in that: The upper joint (1) is also provided with a safety joint (8).

3. The oil and gas well multi-layer plugging removal and production integrated tool according to claim 1, characterized in that: The sliding sleeve (4) is connected to the upper joint (1) via a plurality of shear pins (3).

4. The oil and gas well multi-layer plugging removal and production integrated tool according to claim 3 is characterized in that: The shear pins (3) are distributed circumferentially along the sliding sleeve (4).

5. The oil and gas well multi-layer plugging removal and production integrated tool according to claim 1, characterized in that: The end of the sliding sleeve (4) connected to the upper joint (1) is connected with a conical ring, and the hydraulic hand-loosening ball (2) is arranged in the conical ring.

6. The oil and gas well multi-layer plugging removal and production integrated tool according to claim 1, characterized in that: The end of the sliding sleeve (4) is threadedly connected to the tail pipe plug (6).

7. The oil and gas well multi-layer plugging removal and production integrated tool according to claim 1, characterized in that: The sliding sleeve (4) and the hydraulic hand-throwing ball (2) are both made of soluble materials.

8. The oil and gas well multi-layer plugging removal and production integrated tool according to claim 1, characterized in that: The tail pipe plug (6) is made of soluble material.

9. An oil and gas well unblocking device, characterized in that: The invention comprises the oil and gas well multi-layer plugging removal and production integrated tool as claimed in any one of claims 1 to 8.

10. A method for removing multi-layer plugging in oil and gas wells using the tool according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Connect the oil and gas well multi-layer plugging removal and production integrated tool to the oil pipe; S2: lower the connected oil and gas well multi-layer plugging removal and production integrated tool into the well; S3: aligning the injection hole (5) of the oil and gas well multi-layer unblocking production integrated tool lowered into the well with the layer to be unblocked; S4: Pumping high-pressure unblocking liquid into the oil pipe string, opening the sliding sleeve (4), exposing the injection hole (5), setting the packer (7), and unblocking the layer to be unblocked; S5: After the unblocking is completed, the oil pipe string is lifted, the packer (7) is unblocked, and the injection hole (5) of the oil and gas well multi-layer unblocking production integrated tool is aligned with the next layer to be unblocked, and S4 is repeated to unblock the next layer to be unblocked; S6: Repeat S4 and S5 until all the layers to be unblocked are unblocked, and the oil and gas well multi-layer unblocking is completed.

Images