Soluble temporary plugging screen pipe

Abstract

The utility model discloses a soluble temporary plugging screen pipe which comprises a screen pipe base pipe, a plurality of holes are formed in the screen pipe base pipe, temporary plugging structures are arranged in part of the holes, and pressure opening devices are arranged in the other part of the holes. The screen pipe base pipe is sleeved with a screen mesh assembly. According to the base pipe with the hole, temporary blocking of the base pipe is achieved through the temporary blocking structure and the one-way pressure opening device, so that the base pipe can replace the pipe washing function of sand prevention operation, building of a circulation channel is achieved through the opening devices of different pressure levels in the circulation process, and the temporary blocking structure is dissolved after the sand prevention operation is finished; and establishing a flow channel between the in-situ crude oil and the shaft. The device is ingenious in structural design, good in using effect and high in practicability.

Description

Technical Field

[0001] The utility model relates to the field of sand prevention screen pipes in petroleum and natural gas engineering, in particular to a soluble temporary plugging screen pipe. Background Art

[0002] In the technical field of drilling and completion operations in oil and gas fields, mechanical screens are mainly used to block formation sand to ensure stable production of oil wells, so the structure and performance of the screens are particularly important. At present, for formations with strong water absorption and expansion, gravel filling and mechanical screens are mainly used for sand control operations. However, if the reservoir is too long or the wellbore is too small, the risk of filling operations will be too high. In particular, the filling operations of small wellbores require smaller screens and flushing pipes, which will cause the friction of the sand-carrying fluid to be too high, making it impossible to operate. For old wells with sand-producing screens and damaged wells, small screens are required for secondary sand control. The structure of the small screen and the size of the service tools are further reduced, making filling and sand control difficult. Only simple mechanical screens can be used, and secondary filling and sand control are not possible. In summary, the current conventional mechanical screen filling and sand control applications mainly have the following problems:

[0003] (1) The sand control reservoir section of the extended displacement well is too long and the wellbore is small. The friction resistance of the flushing pipe during the filling process is high, making it impossible to carry out large-volume filling and sand control operations;

[0004] (2) For small wellbore sand control, small-size screen pipes are required. It is impossible to run a flush pipe for filling operations, so only simple sand control methods can be used;

[0005] (3) For secondary sand prevention in sand-producing wells, a separate sand flushing string is required to ensure the cleanliness of the wellbore. Utility Model Content

[0006] In order to solve the above technical problems, the utility model provides a soluble temporary plugging screen pipe, which uses a temporary plugging base pipe to replace the flushing operation to complete the sand flushing and sand prevention operations in one drilling trip, and later dissolves the soluble temporary plugging piece in the base pipe hole to establish a flow channel between the formation and the screen pipe to realize production operations.

[0007] The present application is implemented by adopting the following technical solutions.

[0008] A soluble temporary plugging screen pipe comprises a screen pipe base pipe, a plurality of holes are formed on the screen pipe base pipe, a part of the holes are provided with temporary plugging structures, and another part of the holes are provided with pressure opening devices; a screen assembly is provided on the outer sleeve of the screen pipe base pipe.

[0009] Furthermore, the temporary plugging structure includes a soluble temporary plugging sheet, and the soluble temporary plugging sheet is arranged on a side of the hole close to the screen assembly.

[0010] Furthermore, a soluble temporary plugging piece installation groove is formed on the side of the hole close to the screen assembly, the cross-section of the soluble temporary plugging piece installation groove is trapezoidal, and the area on the side close to the screen assembly is larger than the area on the side away from the screen assembly.

[0011] Furthermore, the pressure opening device includes a base, which is arranged on the side of the hole away from the screen assembly; the center of the base is connected to a fixed rod, a blocking piece is passed through the fixed rod, and a pressure spring is arranged between the blocking piece and the base.

[0012] Furthermore, the base is provided with a flow hole.

[0013] Furthermore, the cross-section of the hole for installing the pressure opening device is trapezoidal, and the hole diameter on the side away from the screen assembly is larger than the hole diameter on the side close to the screen assembly.

[0014] Furthermore, a plurality of guide support ribs are provided between the screen tube base pipe and the screen mesh assembly.

[0015] Furthermore, the screen assembly comprises a screen support net, a sand retaining screen and a screen protection cover which are sequentially sleeved outside the screen base pipe.

[0016] This application has the following beneficial effects.

[0017] 1. The utility model realizes the replacement of flushing pipe operation with base pipe in filling sand control operation, increases the inner diameter of the filling operation circulation channel, significantly reduces the friction resistance of sand control operation, and further improves the distance limit of reservoir sand control operation;

[0018] 2. The utility model solves the problem of excessive filling pressure by setting one-way opening devices with different pressure levels, effectively improving the success rate of filling operations;

[0019] 3. The utility model adopts temporary plugging materials to plug the base pipe hole, which can replace the conventional sand control blind pipe;

[0020] 4. The utility model breaks through the limitation that the screen pipe size is too small to meet the secondary sand control operation, and provides a new tool for the future sand control of oil fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the utility model;

[0022] Figure 2 It is a side view of the utility model;

[0023] Figure 3 This is a structural schematic diagram of the temporary plugging hole of the utility model;

[0024] Figure 4 It is a structural schematic diagram of the pressure opening device of the utility model;

[0025] Figure 5 It is a structural schematic diagram of a base of a pressure opening device of the utility model.

[0026] Among them, 1. screen base pipe; 2. temporary plugging structure; 3. pressure opening device; 4. screen support net; 5. sand retaining screen; 6. screen protection cover; 7. diversion support rib; 8. screen assembly; 9. soluble temporary plugging piece; 10. pressure spring; 11. plugging piece; 12. base; 13. flow hole; 14. fixing rod. DETAILED DESCRIPTION

[0027] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0028] like Figure 1-5 As shown, a soluble temporary plugging screen includes a screen base pipe 1, on which a plurality of holes are pre-set to provide an installation body for subsequent temporary plugging materials and a one-way pressure opening device. Among them, a temporary plugging structure 2 is provided in a part of the holes, and a pressure opening device 3 is provided in another part of the holes. The pressure opening device 3 can be designed as a one-way opening valve of different pressure levels. The number and arrangement of the temporary plugging structure 2 and the pressure opening device 3 can be adjusted according to the design of the oilfield sand control plan. The screen base pipe 1 is provided with a screen assembly 8 on its outer shell.

[0029] Specifically, a soluble temporary plugging sheet installation groove is formed in the hole of the temporary plugging structure 2, close to the side of the screen assembly 8, and the soluble temporary plugging sheet 9 is installed in the soluble temporary plugging sheet installation groove; preferably, the cross-section of the soluble temporary plugging sheet installation groove is trapezoidal, and the area on the side close to the screen assembly 8 is larger than the area on the side away from the screen assembly 8.

[0030] The pressure opening device 3 of the present application includes a base 12, a fixed rod 14, a pressure spring 10 and a movable plug 11. Specifically, the base 12 is arranged on the side of the hole away from the screen assembly 8, the center of the base 12 is connected to the fixed rod 14, and a plurality of flow holes 13 are arranged around the fixed rod 14; the free end of the fixed rod 14 is penetrated with a plug 11, and a pressure spring 10 is arranged between the plug 11 and the base 12, and the pressure spring 10 is sleeved on the fixed rod 14, and the fixed rod 14 is used to install the pressure spring 10 and ensure the axial movement of the spring. Under the action of the pressure spring 10, the plug 11 can reciprocate along the fixed rod 14. The pressure spring 10 can be set to different pressure levels. In addition, the cross section of the hole where the pressure opening device 3 is installed is also trapezoidal, but the aperture of the hole away from the screen assembly 8 is larger than the aperture of the side close to the screen assembly 8. In this way, when the pressure spring 10 is compressed, a flow channel can be formed between the plug 11 and the hole wall.

[0031] In the present application, a plurality of guide support ribs 7 are arranged between the screen base pipe 1 and the screen assembly 8 to form a liquid flow channel for the filling operation. The screen assembly 8 comprises a screen support net 4, a sand retaining screen 5 and a screen protection cover 6. The screen support net 4 and the sand retaining screen 5 are wound around the screen base pipe 1, and the screen protection cover 6 is used as the outermost layer to temporarily plug the screen as a whole.

[0032] The perforated base pipe of the present application realizes temporary blocking of the base pipe through a temporary blocking structure and a one-way pressure opening device, thereby realizing the pipe flushing effect of the base pipe replacing the sand control operation. During the circulation process, the opening devices of different pressure levels are used to establish a circulation channel. After the sand control operation is completed, the temporary blocking structure is dissolved to establish a flow channel between the formation crude oil and the wellbore.

[0033] The working principle of the utility model is as follows:

[0034] During the oil well sand prevention operation, the screen pipes are connected in sequence through threads and lowered into the well. The soluble temporary plugging piece 9 and the pressure opening device 3 are used to realize that the screen pipes are in a closed state after entering the well. The pump is turned on for positive circulation operation, and the liquid returns through the bottom of the screen pipe to clean the impurities in the wellbore and complete the sand flushing operation.

[0035] During the filling operation, the completion fluid carries the filling gravel and accumulates continuously in the screen and the formation. The gravel is filtered by the screen assembly 8 and remains in the annulus. The completion fluid flows to the bottom of the screen through the guide support ribs 7, enters the base pipe and returns to the ground. When the thickness of the gravel layer continues to increase, the completion fluid flow channel gradually becomes longer, resulting in increased friction resistance. The completion fluid compresses the pressure spring 10 and the plug 11 in the pressure opening device 3 through pressure, and no longer needs to return through the bottom of the screen. It enters the base pipe through the pressure opening device 3 to reduce the filling friction resistance.

[0036] After the sand control operation is completed, the soluble temporary plugging sheet 9 is dissolved by pumping in the dissolving material, the flow channel between the inside of the screen and the formation is opened, and the formation crude oil flows into the inside of the screen through the holes for production operation.

[0037] The embodiments of this specific implementation method are all preferred embodiments of the utility model, and are not intended to limit the protection scope of the utility model. Therefore, all equivalent changes made based on the structure, shape, and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A soluble temporary plugging screen pipe, comprising a screen pipe base pipe (1), wherein a plurality of holes are formed on the screen pipe base pipe (1), characterized in that: A temporary plugging structure (2) is provided in a part of the holes, and a pressure opening device (3) is provided in another part of the holes; and a screen assembly (8) is provided on the outer shell of the screen tube base pipe (1).

2. The soluble temporary plugging screen according to claim 1, characterized in that: The temporary plugging structure (2) comprises a soluble temporary plugging sheet (9), and the soluble temporary plugging sheet (9) is arranged on a side of the hole close to the screen assembly (8).

3. The soluble temporary plugging screen according to claim 2, characterized in that: The hole forms a soluble temporary plugging piece installation groove on the side close to the screen assembly (8); the cross section of the soluble temporary plugging piece installation groove is trapezoidal, and the area on the side close to the screen assembly (8) is larger than the area on the side away from the screen assembly (8).

4. The soluble temporary plugging screen according to claim 1, characterized in that: The pressure opening device (3) comprises a base (12), which is arranged on the side of the hole away from the screen assembly (8); the center of the base (12) is connected to a fixing rod (14), a blocking piece (11) is passed through the fixing rod (14), and a pressure spring (10) is arranged between the blocking piece (11) and the base (12).

5. The soluble temporary plugging screen according to claim 4, characterized in that: The base (12) is provided with a flow hole (13).

6. The soluble temporary plugging screen according to claim 4, characterized in that: The cross section of the hole for installing the pressure opening device (3) is trapezoidal, and the hole diameter on the side away from the screen assembly (8) is larger than the hole diameter on the side close to the screen assembly (8).

7. The soluble temporary plugging screen according to claim 1, characterized in that: A plurality of flow guide support ribs (7) are provided between the screen tube base pipe (1) and the screen mesh assembly (8).

8. The soluble temporary plugging screen according to claim 1, characterized in that: The screen assembly (8) comprises a screen support net (4), a sand retaining screen (5) and a screen protection sleeve (6) which are sequentially sleeved outside the screen base pipe (1).

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