Carbon dioxide injection well gas injection valve capable of passing through testing tool

Abstract

The utility model discloses a carbon dioxide injection well gas injection valve capable of passing through a test tool, a spring limiting sleeve and an outer cylinder are sequentially connected outside a central pipe provided with a liquid flow hole from top to bottom, a spring and a piston are arranged between the spring limiting sleeve and the outer cylinder, and the spring is positioned between the spring limiting sleeve and the piston; in the normal gas-water alternate oil displacement process of the carbon dioxide injection well, gas and water enter an oil layer from a liquid flow hole of the central pipe; during underground testing, a testing tool can be tripped in from the center hole of the center pipe. The gas injection valve can be connected to any position in the gas injection tubular column, passing of a later test instrument is not affected, and the gas injection valve does not need to be placed at the lowermost end of the gas injection tubular column, so that the risk that the gas injection valve is buried by underground dirt is reduced. The testing requirement of a carbon dioxide injection well in the gas injection process is met, and meanwhile the corrosion rate of a casing pipe near an oil layer below the packer due to the gas-water alternate injection technology is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the gas injection tool in oil industry oil production well, concretely is a kind of carbon dioxide injection well injection gas valve capable of being tested tool. BACKGROUND

[0002] To improve oil recovery, supplement formation energy, CO2 miscible flooding is the new technology emerging in recent years, and many oil reservoirs have carried out CO2 flooding development. Some gas injection wells are deployed in the development block, and gas injection pipe column is used for gas injection production to improve the recovery of crude oil.

[0003] The gas injection valve needs to be used in the CCUS gas injection pipe column. CCUS refers to the process of capturing carbon dioxide in industrial production by various means and then storing or utilizing.

[0004] At present, the gas injection valve connected in the gas injection pipe column should be connected to the lower end of the packer in the gas injection pipe column for the protection of the casing between the packer below and the oil layer above and the needs of production and testing, but because the existing gas injection valve has no inner diameter, its function is only to inject gas unidirectionally through the valve body. In order to achieve the purpose of downhole testing, the existing gas injection valve can only be connected to the lowermost end of the pipe column. In this way, the casing below the packer in the gas injection pipe column cannot be protected, and problems such as sand burying and failure of the gas injection valve are easily caused.

[0005] For example, the following prior art:

[0006] The downhole gas injection pipe column disclosed in the authorized announcement No. CN102536183A provides a downhole gas injection pipe column that can prevent injected gas from returning and can reverse circulation without the need to drop and fish a plug. The packer is installed above the oil layer, the lost-return adapter is connected above the packer, the gas injection valve is connected below the packer, the upper end of the tubing string is connected to the wellhead device, the lower end of the tubing string is connected to the sleeve valve and the sealing plug from top to bottom, the sealing plug is inserted into the lost-return adapter, the sleeve valve and the gas injection valve are both one-way valves, the flow direction of the sleeve valve is from the tubing-casing annulus to the tubing, and the flow direction of the gas injection valve is from inside to outside. The existing technology needs to repeatedly drop and fish a plug, which is avoided, and the risk caused by disassembling the wellhead due to insufficient understanding of the downhole conditions in the existing technology is prevented. The installed sleeve valve not only meets the needs of well killing, but also meets the needs of periodic replacement of tubing-casing annulus protection fluid.

[0007] The gas injection valve used in the above pipe column is a one-way valve, and gas can only flow from inside to outside of the gas injection valve, but gas cannot flow from outside to inside of the pipe column. When gas injection is stopped, the packer seals the tubing-casing annulus, the gas injection valve prevents gas from entering the gas injection pipe column, and the upper gas injection pipe column does not need to be pressure killed when it is pulled out or lowered, which avoids the trouble of repeatedly dropping and fishing a plug in the original technology.

[0008] CN107178347B discloses a long-acting CO2 injection string and an operating method. The invention includes an upper string and a lower string. The upper string includes a tubing sleeved in a casing. The tubing is sequentially provided with a circulating well flushing sliding sleeve, a hydraulic anchor, a hanging ring device and a sealing insert tube from top to bottom. The lower string includes a sealing cylinder and a packer sequentially provided on the tubing. The bottom of the lower string is provided with a setting ball seat and a double-stage check valve. The lower string is fixed on the inner wall of the casing through the anchor shoe of the packer. The circulating well flushing sliding sleeve is closed during water injection and opened during backwashing. The double-stage check valve is pushed upward by the throttling pressure difference to close the liquid throttling passage when the casing pressure is higher than the oil pressure. If the stage fails, the liquid continues to flow upward to push the valve ball to block the valve seat, which cooperates with the permanent packer to achieve downhole shut-in and safe production.

[0009] A CO2 injection string is disclosed in the paper "CO2 injection string technology research" published in Petroleum Machinery, Vol. 41, No. 12, 2013. The string structure is as follows: from bottom to top, screen + screen pipe + bottom check valve + tubing + Y441 packer + butterfly one-way valve + release back connection cylinder + tubing to wellhead. The string can achieve the function of backwashing to replace the annulus protection fluid. During the string running and production, the bottom check valve is used to achieve packer constant pressure setting and one-way gas injection process.

[0010] A new type of CO2 injection string is disclosed in the paper "Development and application of a new type of CO2 injection string" published in Oil and Gas Reservoir Evaluation and Development, Vol. 9, No. 3, 2019. The string structure is as follows: gas-tight tubing + sliding sleeve + Y445J packer + external upset tubing + multifunctional gas injection valve. The double-grip anchor mechanism of the string enables the packer to have bidirectional pressure-bearing capacity after completing hydraulic setting, which can bear pressure for a long time and in both directions, effectively prevents string creep, and ensures the sealing performance of the rubber sleeve.

[0011] The gas injection valve or bottom check valve in the above string can be well applied in continuous gas injection, but when gas-water alternating displacement is used, the packer in the string cannot be lowered to the vicinity of the oil layer due to the influence of the temperature resistance and pressure resistance parameters of the packer. In addition, late testing is required, so the spacing between the packer and the gas distributor must be increased to meet the functional requirements of the string. However, when this string structure is used, the casing below the packer above the oil layer becomes a dead space that is completely occupied by gas, leading to serious corrosion of the casing, greatly affecting the service life of the CO2 injection well. In addition, the gas injection valve is at the lowest end of the string, which is easily buried and fails by the downhole dirt, leading to the failure of the gas injection string. Therefore, a CO2 injection well gas injection valve that can pass through the testing tool is urgently needed to solve the above problems. Practical new type content

[0012] The utility model discloses a carbon dioxide injection well gas injection valve capable of passing through the testing tool, improves the structure of the existing gas injection valve, solves the defect that the testing tool cannot pass through when the gas-water alternating displacement injection well is downhole tested. Meet the testing demand of gas injection well, protect the casing between the packer below and the oil layer above in the gas injection string. Prolong the service life of the gas injection string in the gas injection well, reduce the production cost.

[0013] The technical solution of the utility model is:

[0014] A carbon dioxide injection well gas injection valve capable of passing through the testing tool, wherein:

[0015] The outer surface of the center pipe provided with the liquid flow hole is sequentially connected with the spring limiting sleeve and the outer cylinder from top to bottom;

[0016] The spring and the piston are installed between the spring limiting sleeve and the outer cylinder, and the spring is located between the spring limiting sleeve and the piston;

[0017] During the normal gas-water alternating displacement oil process of the carbon dioxide injection well, gas and water enter the oil layer from the liquid flow hole of the center pipe;

[0018] During the downhole testing, the testing tool can be lowered into the center hole of the center pipe.

[0019] Preferably, the outer wall of the center pipe is sequentially provided with a guard step, a spring limiting sleeve connecting section, a piston moving section and an outer cylinder connecting section from top to bottom, wherein:

[0020] The spring limiting sleeve connecting section below the guard step is provided with external threads and is threadedly connected with the spring limiting sleeve;

[0021] The piston moving section is a light pipe section, so that the spring and the piston can move up and down on the outer surface;

[0022] The outer cylinder connecting section is provided with external threads on the outer surface and is threadedly connected with the outer cylinder.

[0023] Preferably, the liquid flow hole in the center pipe is provided in two or more; the length of the spring limiting sleeve connecting section is greater than the length of the threaded connecting section in the spring limiting sleeve.

[0024] Preferably, a conical transition section is arranged between the upper part of the guard step and the pipe body of the center pipe, and the maximum outer diameter of the guard step is consistent with the outer diameter of the gas injection string.

[0025] Preferably, the inner circle of the spring limiting sleeve is a non-equal-diameter inner circle, and the upper inner circle is smaller than the lower inner circle; the upper inner circle of the spring limiting sleeve is provided with internal threads and is threadedly connected with the spring limiting sleeve connecting section in the center pipe; and the lower inner circle of the spring limiting sleeve is fixed with one end of the spring in the cavity formed by the center pipe.

[0026] Preferably, the piston is a non-equal-diameter cylindrical body, the other end of the spring is fixed in the upper inner cavity of the piston, and the lower outer circle is a conical body.

[0027] Preferably, the inner circle of the outer cylinder is a non-equal-diameter inner circle and is sequentially provided with a piston matching cavity, a sealing cavity and a connecting fastening cavity from top to bottom.

[0028] The piston matching cavity and the sealing cavity are each provided with one or more than one sealing member; the piston matching cavity is a conical cavity matched with the conical body of the lower part of the piston; the connecting fastening cavity is provided with an internal thread and is threadedly connected with the outer cylinder connecting section in the central pipe; and the liquid flow hole in the central pipe is correspondingly arranged at the cavity bottom of the piston matching cavity.

[0029] The cavity surface of the piston matching cavity and the sealing cavity provided with the sealing member is a precision finishing sealing surface.

[0030] A locking pin is further arranged at the thread connection between the spring limiting sleeve and the spring limiting sleeve connecting section and the outer cylinder connecting section in the central pipe; and the carbon dioxide injection well gas injection valve is connected to the lower end of the packer in the gas injection pipe column.

[0031] Compared with the prior art, the utility model has the following advantages:

[0032] (1) The utility model has simple structure, is lowered into a well together with a gas injection pipe column, and is simple in construction operation.

[0033] (2) The utility model has a large inner diameter of the central pipe, can pass the testing instrument used in the later stage of the well, and meets the requirement of well bottom testing.

[0034] (3) The utility model meets the testing requirement, can be directly connected to the lower end of the packer in the gas injection pipe column, and because the packer on the gas injection pipe column is closely connected with the gas injection valve, the distance between the packer and the gas injection valve is minimum, so the gas top dead cavity formed is also minimum, thereby effectively reducing the corrosion rate of the casing near the oil layer below the packer due to the gas-water alternate injection process, prolonging the service life of the downhole old well casing and the service life of the oil well.

[0035] (4) The utility model can be connected to any position in the gas injection pipe column, does not affect the passing of the testing instrument in the later stage, because the utility model does not need to be arranged at the lowermost end of the gas injection pipe column, reducing the risk of the gas injection valve being buried due to downhole dirt.

[0036] The utility model satisfies the carbon dioxide injection well in the gas injection process test demand at the same time, has reduced the corrosion rate of the casing below the packer in the gas water alternate injection process. Since the utility model solves the defect that the current gas injection valve cannot pass through the test tool, can carry out downhole test in the gas injection process, provides credible data support for the scheme adjustment of the oil reservoir development, makes the contribution for further improving the oil reservoir recovery. Has the remarkable use effect and can obtain very good economic benefit and social benefit, the popularization space is huge. BRIEF DESCRIPTION OF DRAWINGS

[0037] The accompanying drawings are included to provide a further understanding of the utility model, and constitute a part of the specification, and are used to explain the utility model together with embodiments of the utility model, and do not constitute the limitation to the utility model. In the drawings:

[0038] Figure 1 It is the structural schematic diagram of the utility model.

[0039] Figure 2 It is the structural schematic diagram of the center tube in Figure 1

[0040] Figure 3 It is the structural schematic diagram of the outer tube in Figure 1

[0041] In the drawing:

[0042] Center tube 1, guard stage 1-1, spring limit cover connecting section 1-2, piston moving section 1-3, liquid flow hole 1-4, outer tube connecting section 1-5;

[0043] Spring limit cover 2, piston 3;

[0044] Outer tube 4, piston cooperation cavity 4-1, sealing cavity 4-2, connecting fastening cavity 4-3;

[0045] Spring 5. DETAILED DESCRIPTION

[0046] The drawings are only for reference and explanation, and are not used to limit the protection scope of the utility model. The technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings of the embodiments of the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the ordinary skill in the art without making creative labor belong to the protection scope of the utility model.

[0047] ​​In order to make the purpose, technical scheme and advantages of the utility model more clearly, the following will be further described in detail in combination with the drawings and examples.

[0048] In the description of the utility model, it should be understood that the orientation or position relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model. In addition, in the description of the utility model, the meaning of "a plurality of" is two or more than two, unless otherwise explicitly and specifically limited.

[0049] Referring to Figures 1-3 A carbon dioxide injection well injection gas valve capable of passing through a testing tool, wherein:

[0050] The outer surface of the center pipe 1 provided with the liquid flow hole 1-4 is sequentially connected with the spring limiting sleeve 2 and the outer cylinder 4 from top to bottom;

[0051] The spring 5 and the piston 3 are installed between the spring limiting sleeve 2 and the outer cylinder 4, and the spring 5 is located between the spring limiting sleeve 2 and the piston 3;

[0052] In the normal gas-water alternating displacement process of the carbon dioxide injection well, gas and water enter the oil layer from the liquid flow hole 1-4 of the center pipe 1;

[0053] During downhole testing, the testing tool can be lowered into the center hole of the center pipe 1.

[0054] The utility model is connected in the gas injection string, and in the normal gas injection and water injection alternating displacement process, gas / water is injected through the center hole of the center pipe 1, after the string is filled with gas / water, the injected gas / water passes through the liquid flow hole 1-4 and opens the piston 3, enters the oil layer and completes the injection task.

[0055] The center hole of the center pipe 1 in the utility model is larger than the outer diameter of the testing tool, the testing tool can be lowered below the oil layer through the center pipe 1 of the utility model, and the testing task of the injection well in the later stage using the utility model is completed.

[0056] The utility model discloses, need not deepen the connection depth of injection gas valve in injection pipe column, complete the normal production demand and test demand of injection well, in the case of realizing the normal production use of gas / water alternation drive injection well, the existing injection gas valve is solved when doing downhole testing, because the existing injection gas valve has no internal passage, for the convenience of downhole testing, can only be installed at the bottom end of injection pipe column, the corrosion problem of casing between the packer below and the oil layer above caused by the injection gas valve connected at the lower end of injection pipe column and the problem of being buried and blocked, overcome the defect that the testing tool can not pass through the existing injection gas valve and all the adverse consequences brought.

[0057] The utility model satisfies the production use and test demand of carbon dioxide injection well, can be connected in injection pipe column according to normal design position, protects the oil well casing below the packer sealing position in pipe column, greatly reduces the corrosion problem of casing between the packer and the oil layer above in the existing injection pipe column and the injection gas valve blockage problem, prolongs the service life of injection pipe column and old well casing in injection gas well, significantly facilitates the selection of tool placement position in injection pipe column, effectively reduces the later maintenance cost.

[0058] On the basis of the above embodiment one, the utility model also has the following embodiments:

[0059] A preferred embodiment: see Figure 2 The outer wall of the center pipe 1 is sequentially provided with a blocking step 1-1, a spring limiting sleeve connecting section 1-2, a piston moving section 1-3 and an outer cylinder connecting section 1-5 from top to bottom, wherein:

[0060] The spring limiting sleeve connecting section 1-2 below the blocking step 1-1 is provided with external threads for thread connection with a spring limiting sleeve 2;

[0061] The piston moving section 1-3 is a light pipe section for upward and downward movement of the spring 5 and the piston 3 on the outside;

[0062] The outer cylinder connecting section 1-5 is provided with external threads on the outside for thread connection with an outer cylinder 4.

[0063] A preferred embodiment: the liquid flow hole 1-4 in the center pipe 1 is provided in two or more; the length of the spring limiting sleeve connecting section 1-2 is greater than the length of the thread connecting section in the spring limiting sleeve 2, facilitating adjustment of the elastic force of the spring 5.

[0064] A preferred embodiment: a conical transition section is arranged between the upper part of the blocking step 1-1 and the pipe body of the center pipe 1, and the maximum outer diameter of the blocking step 1-1 is consistent with the outer diameter of the injection pipe column, so as to form protection for the spring limiting sleeve 2 and the piston 3 installed below when the pipe column is lowered.

[0065] A preferred embodiment: the inner circle of the spring limiting sleeve 2 is a non-equal diameter inner circle, and the upper inner circle is smaller than the lower inner circle, the upper inner circle of the spring limiting sleeve 2 is provided with internal threads and is threadedly connected with the spring limiting sleeve connecting section 1-2 in the central pipe 1; the lower inner circle of the spring limiting sleeve 2 is placed in one end of the spring 5 in the cavity formed by the central pipe 1.

[0066] A preferred embodiment: the piston 3 is a non-equal diameter cylindrical body, the other end of the spring 5 is placed in the upper inner cavity of the piston 3, and the lower outer circle is a conical body.

[0067] A preferred embodiment: see Figure 3 , the inner circle of the outer cylinder 4 is a non-equal diameter inner circle, and is sequentially provided with a piston matching cavity 4-1, a sealing cavity 4-2 and a connecting and fastening cavity 4-3 from top to bottom.

[0068] A preferred embodiment: one or more than one sealing member is arranged in the piston matching cavity 4-1 and the sealing cavity 4-2; the piston matching cavity 4-1 is a conical cavity matched with the conical body at the lower part of the piston 3, the connecting and fastening cavity 4-3 is provided with internal threads and is threadedly connected with the outer cylinder connecting section 1-5 in the central pipe 1; the liquid flow hole 1-1 in the central pipe 1 is correspondingly arranged at the cavity bottom of the piston matching cavity 4-1; in operation, the gas / water in the pipe string can top off the piston 3 and flow into the oil layer from the liquid flow hole 1-1.

[0069] A preferred embodiment: the cavity surface of the piston matching cavity 4-1 and the sealing cavity 4-2 provided with the sealing member is a precision sealing surface, which can further improve the sealing performance of the device.

[0070] A preferred embodiment: a locking pin is further arranged at the thread connection between the spring limiting sleeve 2 and the outer cylinder 4 and the spring limiting sleeve connecting section 1-2 and the outer cylinder connecting section 1-5 in the central pipe 1; the carbon dioxide injection well gas injection valve is connected to the lower end of the packer in the gas injection pipe string, and this connection position is also the best position for protecting the casing. The utility model is connected and installed according to normal production requirements, and can normally perform testing in the gas injection process without being connected to the bottom of the gas injection pipe string.

[0071] In the assembly and connection of the utility model, the spring limiting sleeve 2 is first assembled from the lower end of the central pipe 1 and is threadedly connected with the central pipe 1, then the rivet is assembled;

[0072] then the spring 5 is assembled, then the piston 3 is assembled from the lower end of the central pipe 1, finally the outer cylinder 4 is assembled and is threadedly connected with the central pipe 1, then the rivet is assembled, and the rigid body assembly of the utility model is completed.

[0073] The above-described embodiments are merely typical embodiments, but the utility model is not limited to these embodiments, and a person skilled in the art can make modifications without deviating from the spirit and inspiration of the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, a person skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacement to part of the technical features. Any modification, equivalent replacement, improvement, etc. within the spirit and concept of the utility model should be included in the protection scope of the utility model. Therefore, the protection scope is not limited to the foregoing description.

Claims

1. A carbon dioxide injection valve for wells that can be tested using a testing tool, characterized in that, A spring limiting sleeve and an outer cylinder are connected sequentially from top to bottom to the outside of a central tube with a liquid flow hole. The spring and piston are installed between the spring limiting sleeve and the outer cylinder, with the spring located between the spring limiting sleeve and the piston. During normal gas-water alternating oil displacement in a carbon dioxide injection well, gas and water enter the oil layer through the liquid flow hole in the central tube; during downhole testing, testing tools can be lowered through the central hole of the central tube.

2. A carbon dioxide injection valve for a well that can be tested using a testing tool, as described in claim 1, characterized in that, The outer wall of the central tube is provided with, from top to bottom, a protective step, a spring limiting sleeve connecting section, a piston moving section, and an outer cylinder connecting section, wherein: The spring limiting sleeve connecting section below the retaining step is provided with an external thread that is threadedly connected to the spring limiting sleeve. The piston moving section is a light tube section, which allows the spring and piston to move up and down on the outside; The outer cylinder connecting section is provided with an external thread that connects to the outer cylinder thread.

3. A carbon dioxide injection valve for wells capable of passing a test tool as described in claim 2, characterized in that, The central tube has two or more flow holes; the length of the spring limiting sleeve connecting section is greater than the length of the threaded connecting section in the spring limiting sleeve.

4. A carbon dioxide injection well gas injection valve as described in claim 2, characterized in that, A tapered transition section is provided between the upper part of the protective step and the body of the central tube, and the maximum outer diameter of the protective step matches the outer diameter of the gas injection column.

5. A carbon dioxide injection valve for a well that can be tested using a testing tool, as described in claim 3, characterized in that... The inner circle of the spring limiting sleeve is a non-uniform diameter inner circle with the upper inner circle being smaller than the lower inner circle. The upper inner circle of the spring limiting sleeve is provided with an internal thread that is threadedly connected to the spring limiting sleeve connecting section in the central tube. One end of the spring is fixed in the cavity formed by the lower inner circle of the spring limiting sleeve and the central tube.

6. A carbon dioxide injection valve for a well that can be tested using a testing tool, as described in claim 5, characterized in that... The piston is a non-uniform diameter cylindrical body, with the other end of the spring fixed in the upper inner cavity and the lower outer circle being a cone shape.

7. A carbon dioxide injection valve for a well that can be tested using a testing tool, as described in claim 6, characterized in that... The inner circle of the outer cylinder is a non-uniform diameter inner circle and is provided with a piston mating cavity, a sealing cavity and a connecting fastening cavity in sequence from top to bottom.

8. A carbon dioxide injection valve for a well that can be tested using a testing tool, as described in claim 7, characterized in that... Both the piston mating cavity and the sealing cavity are equipped with one or more seals; the piston mating cavity is a conical cavity that mates with the conical body at the bottom of the piston; the connecting and fastening cavity is provided with internal threads that are threadedly connected to the outer cylinder connecting section in the central tube; the liquid flow hole in the central tube is correspondingly set to the bottom of the piston mating cavity.

9. A carbon dioxide injection valve for a well that can be tested using a testing tool, as described in claim 8, characterized in that... The surfaces of both the piston mating cavity and the sealing cavity containing the seal are precision-machined sealing surfaces.

10. A carbon dioxide injection well gas injection valve capable of passing a test tool as described in any of claims 1-9, characterized in that, The threaded connection between the spring limiting sleeve and the outer cylinder and the spring limiting sleeve connecting section and the outer cylinder connecting section in the central tube is also equipped with anti-loosening nails; the carbon dioxide injection well gas injection valve is connected to the lower end of the packer in the gas injection tubing.

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