Oil layer protector
By designing an oil layer protector containing a spherical cover and a sphere, the problem of washing fluid entering the water-sensitive formation and crude oil flowing to the ground is solved, and the stable production and oil recovery cost of oil wells are achieved.
Patent Information
- Application Number
- CN202311089865.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-28
- Publication Date
- 2025-02-28
AI Technical Summary
During oil production in the oil field, the well washing fluid is prone to enter the water-sensitive formation, resulting in oil well production reduction or no oil output, increasing the cost of oil production. At the same time, crude oil is prone to flow to the ground when the oil is unloaded by the pipe column.
An oil layer protector is designed, arranged in the sleeve, including an outer cylinder, a ball cover, a ball, a mandrel and a transposition sleeve. Through the limit structure of the ball cover and the sphere, the well washing fluid is prevented from entering the mandrel, ensuring that the crude oil does not flow to the ground during the oil discharge process.
It effectively avoids the well washing fluid entering the oil well, prevents oil production from being reduced or oil output, reduces oil production costs, and ensures that crude oil will not flow to the ground when the oil is unloaded on the pipe column.
Smart Images
Figure CN119531752A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of oil field production, and in particular to an oil layer protector. Background Art
[0002] Well washing refers to the process of injecting well washing medium through the wellbore or drill pipe by pumping equipment during well repair operations when the project requires it, carrying the materials in the wellbore to the ground, so as to change the medium properties in the wellbore to meet the operation requirements. Commonly used methods include carbon dioxide well washing and acid well washing. However, after long-term production of oil fields, the formation pressure gradually decreases. At this time, during the well washing and wax removal construction process, the well washing fluid will enter the formation. For some water-sensitive formations, the rock pores will become smaller, which will lead to reduced production of oil wells or even no oil production in subsequent production, thereby adding more costs to oil field production. At the same time, it is necessary to lift the tubing string during the oil production process, so it is necessary to unload the crude oil in the tubing string to prevent it from flowing back to the ground. Therefore, how to prevent the well washing fluid from entering the oil well during the well washing operation and ensure that the crude oil will not flow to the ground when the tubing string is lifted and unloaded is a problem that people in this field need to solve. Summary of the invention
[0003] The object of the present invention is to provide an oil layer protector to prevent well washing fluid from entering the oil well during well washing operation and to ensure that crude oil will not flow to the ground when the pipe string is lifted to unload the oil.
[0004] To achieve this object, the present invention adopts the following technical solutions:
[0005] The oil layer protector is arranged in the casing, and includes:
[0006] An outer cylinder, the inner cavity of which is connected to the sleeve;
[0007] A ball cover is arranged in the inner cavity of the outer cylinder, and the ball cover is provided with a limited space, and the limited space is communicated with the inner cavity of the outer cylinder;
[0008] A sphere is movably arranged in the limited space;
[0009] A core shaft is connected to the ball cover, the interior of the core shaft is connected to the limiting space and the sleeve, and the sphere can be sealed at the bottom of the ball cover to cut off the connection between the core shaft and the ball cover;
[0010] A transposition sleeve is connected to the outer tube and sleeved on the outer side of the core shaft. The transposition sleeve can cut off the communication between the inside of the core shaft and the sleeve.
[0011] As an option, the ball cover includes a ball seat and a cover body, which are arranged to form the limiting space, and the ball seat can limit the ball in the limiting space.
[0012] As an option, a limiting groove is provided through the ball seat, and the inner diameter of the limiting groove is smaller than the diameter of the sphere.
[0013] As an option, the cover body is provided with a plurality of long through holes, and the limiting space is connected to the inner cavity of the outer cylinder through the long through holes.
[0014] Optionally, a plurality of first holes are provided on the outer tube, and the first holes are connected to the inner cavity of the outer tube and the sleeve.
[0015] As an option, a second hole is provided on the core shaft, the second hole is connected to the interior of the core shaft and the sleeve, and the transposition sleeve can be covered on the second hole.
[0016] Optionally, a transposition pin is also included, a first groove is provided on the outer side of the core shaft, and the transposition pin is inserted into the first groove and abuts against the inner wall of the outer cylinder.
[0017] Optionally, a shear pin is also included, a second groove is provided on the outer side of the core shaft, the shear pin is inserted into the second groove and abuts against the inner wall of the outer cylinder.
[0018] Optionally, the transposition sleeve is provided with a transposition groove, the transposition pin and the shear pin are both located in the transposition groove, and when the shear pin breaks, the transposition pin is engaged with the bottom of the transposition groove, and the transposition sleeve opens the second hole of the core shaft.
[0019] Optionally, a plurality of annular seals are provided between the transposition sleeve and the core shaft.
[0020] Beneficial effects of the present invention:
[0021] In the present invention, the outer tube is connected to the ball cover inside and the outer tube is connected to the casing outside, so that the well washing fluid in the outer tube can be introduced into the casing for well washing operation, and a sphere is movably arranged in the limited space inside the sphere cover, and after the well washing fluid enters the sphere cover in the outer tube, it can impact the sphere and press it against the bottom of the sphere cover, so that the well washing fluid will not flow out from the bottom of the sphere cover. Further, the mandrel is connected to the sphere cover and its interior is connected to the limited space, so that during the production process, the crude oil in the mandrel can impact the sphere and press it against the top of the sphere cover, and under the setting that the sphere cover is connected to the inner cavity of the outer tube, the crude oil is introduced into the outer tube. In the present invention, the interior of the mandrel is also connected to the casing, specifically, when the pipe string is lifted to unload oil, the sphere is impacted by the crude oil on its upper part and abuts against the bottom of the sphere cover to cut off the connection between the mandrel and the sphere cover, so that the crude oil can be introduced from the outer tube into the casing, and the crude oil bypasses the sphere cover and is introduced into the interior of the mandrel at the connection point between the mandrel and the mandrel in the casing, so as to achieve oil unloading and prevent the crude oil from flowing to the ground. Optionally, the transposition sleeve is connected to the outer cylinder and sleeved on the outside of the core shaft, which can not only ensure the stable installation of the core shaft and the ball cover, but also cut off the connection between the inside of the core shaft and the casing when it is performing well washing operations, thereby preventing the well washing fluid from entering the inside of the core shaft, and open the connection when it is performing oil unloading operations to ensure smooth unloading of crude oil. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 is a schematic structural diagram of an oil layer protector according to an embodiment of the present invention;
[0023] Figure 2 is a schematic diagram of the oil layer protector according to an embodiment of the present invention in use;
[0024] Figure 3 It is a schematic structural diagram of a ball cover in an oil layer protector according to an embodiment of the present invention.
[0025] In the figure:
[0026] 100-casing; 200-upper oil pipe; 300-rodless pump; 400-telescopic pipe; 500-oil layer protector; 600-packer; 700-lower oil pipe;
[0027] 10-outer cylinder; 20-ball cover; 30-ball body; 40-mandrel; 50-transposition pin; 60-shear pin; 70-transposition sleeve; 101-first hole; 401-second hole;
[0028] 21 - ball seat; 22 - cover body; 201 - limiting through groove; 202 - long through hole. DETAILED DESCRIPTION
[0029] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar parts or parts having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.
[0030] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, it can be a mechanical connection or an electrical connection, it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0031] In the description of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.
[0032] Well washing refers to the process of injecting well washing medium through the wellbore or drill pipe by pumping equipment during well repair operations when necessary, carrying the materials in the wellbore to the ground, so as to change the medium properties in the wellbore to meet the operation requirements. Commonly used methods include carbon dioxide well washing and acid well washing. However, after long-term production of oil fields, the formation pressure gradually decreases. At this time, during the well washing and wax removal construction process, the well washing fluid will enter the formation. For some water-sensitive formations, the rock pores will become smaller, which will lead to reduced production of oil wells or even no oil production in subsequent production, thereby adding more costs to oil field production. At the same time, it is necessary to lift the tubing string during the oil production process, so it is necessary to unload the crude oil in the tubing string to prevent it from flowing back to the ground. Therefore, how to prevent the well washing fluid from entering the oil well during the well washing operation and ensure that the crude oil will not flow to the ground when the tubing string is lifted and unloaded is a problem that people in this field need to solve.
[0033] The technical solution of this embodiment is further explained below with reference to the accompanying drawings and through specific implementation methods.
[0034] like Figure 1-Figure 3As shown, this embodiment provides an oil layer protector, which is arranged in the casing 100, including an outer cylinder 10, a ball cover 20, a sphere 30, a core shaft 40 and a displacement sleeve 70. The inner cavity of the outer cylinder 10 is connected to the casing 100, the ball cover 20 is arranged in the inner cavity of the outer cylinder 10, and the ball cover 20 is provided with a limited space, the limited space is connected to the inner cavity of the outer cylinder 10, the sphere 30 is movably arranged in the limited space, the core shaft 40 is connected to the ball cover 20, the interior of the core shaft 40 is connected to the limited space and the casing 100, the sphere 30 can be sealed at the bottom of the ball cover 20 to cut off the connection between the core shaft 40 and the ball cover 20, the displacement sleeve 70 is connected to the outer cylinder 10 and is sleeved on the outside of the core shaft 40, and the displacement sleeve 70 can cut off the connection between the inside of the core shaft 40 and the casing 100.
[0035] Specifically, in the present invention, the outer cylinder 10 is connected to the ball cover 20 inside and the casing 100 outside, so that the well washing fluid in the outer cylinder 10 can be introduced into the casing 100 for well washing operations, and a sphere 30 is movably arranged in the limited space inside the sphere cover 20. After the well washing fluid enters the sphere cover 20 in the outer cylinder 10, it can impact the sphere 30 and press it against the bottom of the sphere cover 20, so that the well washing fluid will not flow out from the bottom of the sphere cover 20. Further, the core shaft 40 is connected to the sphere cover 20 and its interior is connected to the limited space, so that during the production process, the crude oil in the core shaft 40 can impact the sphere 30 and press it against the top of the sphere cover 20, and under the setting that the sphere cover 20 is connected to the inner cavity of the outer cylinder 10, the crude oil is introduced into the outer cylinder 10. In this embodiment, the interior of the mandrel 40 is also connected to the casing 100. Specifically, when the pipe string is lifted to unload oil, the ball 30, under the impact of the crude oil on its upper part, abuts against the bottom of the ball cover 20 to cut off the connection between the mandrel 40 and the ball cover 20, so that the crude oil can be introduced from the outer cylinder 10 into the casing 100, and the crude oil bypasses the ball cover 20 and enters the interior of the mandrel 40 at the connection between the mandrel 40 and the casing 100, thereby achieving oil unloading. Optionally, the transposition sleeve 70 is connected to the outer cylinder 10 and sleeved on the outside of the mandrel 40, which can not only ensure the stable installation of the mandrel 40 and the ball cover 20, but also can cut off the connection between the interior of the mandrel 40 and the casing 100 when it is performing a well washing operation, preventing the well washing fluid from entering the interior of the mandrel 40, and open its connection when it is performing an oil unloading operation to ensure smooth unloading of crude oil.
[0036] The specific structure of the oil layer protector in this embodiment is described below.
[0037] like Figure 1 and Figure 2As shown, in this embodiment, a casing 100 is placed in the oil well, and the casing 100 is connected with an upper oil pipe 200, a rodless pump 300, a telescopic pipe 400, an oil layer protector 500, a packer 600 and a lower oil pipe 700 in sequence from top to bottom, wherein the oil layer protector 500 includes an outer cylinder 10, a ball cover 20, a ball body 30, a core shaft 40, a transposition pin 50, a shear pin 60 and a transposition sleeve 70. Specifically, the oil layer protector 500 is arranged in the casing 100, which can prevent the well washing fluid from entering the lower oil pipe 700 through the packer 600, and when the upper oil pipe 200 is lifted, the crude oil above the oil layer protector 500 is introduced into the lower oil pipe 700 through the inner annulus of the casing 100, so as to achieve the oil unloading effect.
[0038] like Figure 1 As shown, specifically, the outer cylinder 10 is set as a hollow structure, which is connected to the telescopic tube 400 above. Optionally, both ends of the outer cylinder 10 are provided with threads, so that it can be screwed to the telescopic tube 400 and facilitate the connection of the transposition sleeve 70. Further, a plurality of first holes 101 are provided through the outer cylinder 10, and the two ends of the first holes 101 are respectively connected to the inner cavity of the outer cylinder 10 and the annulus of the casing 100, so as to ensure that the well washing fluid in the outer cylinder 10 can enter the annulus of the casing 100 through the first holes 101 to complete the well washing operation. At the same time, in the subsequent oil unloading process, the remaining crude oil in the outer cylinder 10 can also be introduced into the annulus of the casing 100 to prevent it from flowing to the ground and causing losses.
[0039] Combination Figure 3 As shown, further, the ball cover 20 is arranged in the inner cavity of the outer cylinder 10, and includes two parts, a ball seat 21 and a cover body 22. Specifically, the cover body 22 and the ball seat 21 are arranged as a split structure, and in this embodiment, the two are connected by screw connection, and in other embodiments, the two can also be connected in a detachable manner by other connection methods, so as to facilitate the placement of the ball 30. Specifically, the cover body 22 and the ball seat 21 are surrounded to form a limited space, and the ball 30 is movably arranged in the limited space, and the ball seat 21 can limit the ball 30 in the limited space, so that it cannot fall off in the ball cover 20.
[0040] Optionally, the cover body 22 is provided with a plurality of long through holes 202, and the limiting space is connected to the inner cavity of the outer cylinder 10 through the long through holes 202, so as to realize the connection between the inside of the ball cover 20 and the inner cavity of the outer cylinder 10, and then, under the action of the first hole 101, it is connected to the annulus of the casing 100, which is not only convenient for the well washing fluid to impact the ball 30 in the cover body 22, but also enables the crude oil to enter the inner cavity of the outer cylinder 10 through the long through holes 202 when the ball 30 is impacted by the crude oil below. Specifically, the length of the long through hole 202 is greater than the diameter of the ball 30, and the width of the long through hole 202 is less than the diameter of the ball 30, so as to ensure that the ball 30 is not easy to fall off from the long through hole 202, and then realize the smooth passage of the crude oil.
[0041] Furthermore, a limiting groove 201 connected to the limiting space is provided through the ball seat 21 to ensure the normal circulation of crude oil, and the inner diameter of the limiting groove 201 is smaller than the diameter of the ball 30, so that the ball 30 can be clamped on the top of the limiting groove 201 and limited in the limiting space, so that the well washing fluid cannot enter the limiting groove 201 during the cleaning operation, thus realizing the connection and isolation between the ball seat 21 and the core shaft 40 connected below, and realizing its one-way guiding function. Optionally, a thread is provided on the outside of the ball seat 21 to facilitate the connection of the core shaft 40.
[0042] Combination Figure 1 and Figure 2 As shown, the mandrel 40 is connected to the ball cover 20. In this embodiment, a thread is provided on the inner side of the upper part of the mandrel 40, which is screwed with the outer thread of the ball seat 21 to ensure a stable connection between the mandrel 40 and the ball seat 21. Exemplarily, a first step is provided on the ball seat 21, a second step and a third step are provided on the top of the mandrel 40, an external thread is provided between the bottom surface of the ball seat 21 and the first step surface, and an internal thread is provided between the second step surface and the third step surface of the mandrel 40, so as to realize the screw connection between the ball seat 21 and the mandrel 40, and the first step surface abuts on the second step surface, and the bottom surface of the ball seat 21 abuts on the third step surface, so as to ensure a gap-free connection between the two, avoid liquid from overflowing from the connection, and improve the sealing effect.
[0043] Further, the mandrel 40 is set as a hollow structure, and the interior of the mandrel 40 is connected to the limited space through the limited groove 201, and is blocked by the ball 30 when the ball 30 is blocked at the bottom of the ball seat 21 in the ball cover 20, thereby ensuring that the well washing fluid flows above the ball 30 and does not enter the interior of the mandrel 40. Optionally, a second hole 401 is provided on the mandrel 40, and the two ends of the second hole 401 are respectively connected to the interior of the mandrel 40 and the annulus of the casing 100, so that when unloading oil, the remaining crude oil in the outer cylinder 10 flows into the annulus of the casing 100, and can enter the interior of the mandrel 40 through the second hole 401, and is introduced into the lower oil pipe 700. Optionally, the bottom of the mandrel 40 is provided with a thread, which can be threadedly connected with the packer 600, thereby ensuring the smooth flow of crude oil.
[0044] like Figure 1As shown, the transposition sleeve 70 is sleeved on the outside of the mandrel 40, and the transposition sleeve 70 can cover the second hole 401, that is, the transposition sleeve 70 can cut off the communication between the inside of the mandrel 40 and the annulus of the casing 100. Specifically, a first groove is provided on the outside of the mandrel 40, and the transposition pin 50 is inserted in the first groove and abuts against the inside of the outer tube 10. A second groove is also provided on the outside of the mandrel 40, and the shear pin 60 is inserted in the second groove and abuts against the inner wall of the outer tube 10. Optionally, a transposition groove is provided on the transposition pin 50, and the transposition pin 50 and the shear pin 60 are both located in the transposition groove, so that the transposition sleeve 70 is sandwiched between the outside of the mandrel 40 and the outer tube 10. Exemplarily, the distance between the transposition pin 50 and the second hole 401 is greater than the distance between the shear pin 60 and the second hole 401, and the shear pin 60 can be sheared off. When it breaks, the transposition sleeve 70 can slide upward relative to the mandrel 40 until the transposition pin 50 is engaged with the bottom of the transposition groove, so that the transposition sleeve 70 covering the second hole 401 can be moved away from the second hole 401, thereby opening the second hole 401, thereby connecting the inside of the mandrel 40 and the annulus of the casing 100 through the second hole 401. Optionally, a plurality of annular seals are provided between the transposition sleeve 70 and the mandrel 40 to ensure a stable seal between the two, and when the transposition sleeve 70 covers the second hole 401, the annular seals are located on the upper and lower sides of the second hole 401, thereby preventing crude oil from leaking at this connection during production. Optionally, a threaded hole is provided on the outer side of the transposition sleeve 70, so as to be screwed to the lower part of the outer cylinder 10.
[0045] Working principle: When performing well washing operations, the shear pin 60 abuts against the bottom of the transposition groove, the transposition sleeve 70 covers the second hole 401, and the interior of the core shaft 40 is not connected to the annulus of the casing 100. After the well washing fluid is injected, the well washing fluid impacts the ball 30 through the long through hole 202, causing it to abut against the ball seat 21 and block the limiting through groove 201, so that the interior of the core shaft 40 is not connected to the limiting space and the inner cavity of the outer tube 10. As a result, the well washing fluid flows into the annulus of the casing 100 through the first hole 101 for well washing, and cannot enter the core shaft 40. During normal production, similarly, the shear pin 60 abuts against the bottom of the transposition groove, the transposition sleeve 70 covers the second hole 401, the interior of the core shaft 40 is not connected to the annulus of the casing 100, and the crude oil inside the core shaft 40 impacts the sphere 30, causing it to abut against the top of the cover body 22, ensuring that the interior of the core shaft 40 is connected to the limited space, and the crude oil passes through the long through hole 202 and enters the inner cavity of the outer cylinder 10 to ensure production and oil extraction. When the whole pipe string is lifted during the oil unloading operation, the ball 30 is again blocked on the limiting groove 201 under the impact of the remaining crude oil in the inner cavity of the outer cylinder 10, so that the interior of the core shaft 40 is not connected with the limiting space. At this time, the shear pin 60 breaks, and the displacement sleeve 70 moves upward relative to the core shaft 40 until the displacement pin 50 abuts against the bottom of the displacement groove. The displacement sleeve 70 opens the second hole 401, and the interior of the core shaft 40 is connected with the annulus of the casing 100, so that the remaining crude oil in the inner cavity of the outer cylinder 10 can flow into the core shaft 40 under the action of the first hole 101, the annulus of the casing 100 and the second hole 401. Therefore, the oil layer protector 500 in this embodiment can not only prevent the well washing fluid from entering the oil well during the well washing operation, but also ensure that the crude oil will not flow to the ground when the pipe string is lifted for oil unloading.
[0046] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.
Claims
1. An oil layer protector, arranged in a casing (100), characterized in that: include: An outer cylinder (10), the inner cavity of the outer cylinder (10) being connected to the sleeve (100); A ball cover (20) is arranged in the inner cavity of the outer cylinder (10), and the ball cover (20) is provided with a limited space, and the limited space is connected to the inner cavity of the outer cylinder (10); A spherical body (30) movably disposed in the limiting space; A core shaft (40) is connected to the ball cover (20); the interior of the core shaft (40) is connected to the limiting space and the sleeve (100); the sphere (30) can be sealed at the bottom of the ball cover (20) to cut off the connection between the core shaft (40) and the ball cover (20); A transposition sleeve (70) is connected to the outer cylinder (10) and sleeved on the outside of the core shaft (40). The transposition sleeve (70) can cut off the communication between the inside of the core shaft (40) and the sleeve (100).
2. The oil layer protector according to claim 1, characterized in that: The ball cover (20) comprises a ball seat (21) and a cover body (22), which are arranged to form the limiting space, and the ball seat (21) can limit the ball (30) in the limiting space.
3. The oil layer protector according to claim 2, characterized in that: The ball seat (21) is provided with a limiting groove (201) extending therethrough, and the inner diameter of the limiting groove (201) is smaller than the diameter of the ball (30).
4. The oil layer protector according to claim 2, characterized in that: The cover body (22) is provided with a plurality of long through holes (202), and the limiting space is connected to the inner cavity of the outer cylinder (10) through the long through holes (202).
5. The oil layer protector according to claim 1, characterized in that: The outer cylinder (10) is provided with a plurality of first holes (101), and the first holes (101) are connected to the inner cavity of the outer cylinder (10) and the sleeve (100).
6. The oil layer protector according to claim 1, characterized in that: The core shaft (40) is provided with a second hole (401), the second hole (401) is connected to the interior of the core shaft (40) and the sleeve (100), and the transposition sleeve (70) can be covered on the second hole (401).
7. The oil layer protector according to any one of claims 1 to 6, characterized in that: It also includes a shift pin (50). A first groove is arranged on the outer side of the core shaft (40). The shift pin (50) is inserted into the first groove and abuts against the inner wall of the outer cylinder (10).
8. The oil layer protector according to claim 7, characterized in that: It also includes a shear pin (60). A second groove is provided on the outer side of the core shaft (40). The shear pin (60) is inserted into the second groove and abuts against the inner wall of the outer cylinder (10).
9. The oil layer protector according to claim 8, characterized in that: The transposition sleeve (70) is provided with a transposition groove, the transposition pin (50) and the shear pin (60) are both located in the transposition groove, and when the shear pin (60) breaks, the transposition pin (50) is engaged with the bottom of the transposition groove, and the transposition sleeve (70) opens the second hole (401) of the core shaft (40).
10. The oil layer protector according to any one of claims 1 to 6, characterized in that: A plurality of annular seals are arranged between the transposition sleeve (70) and the core shaft (40).