A sealing ring sealing aid material and application thereof

Abstract

The application discloses a sealing ring sealing aid material, which is composed of the following components in mass parts: 30-100 parts of hydraulic oil, 0-5 parts of an oily thickening agent, 5-25 parts of a water-swelling agent and 10-30 parts of a proppant. The application also discloses application of the sealing ring sealing aid material as a sealing ring sealing aid in oil exploitation. The application aims at the deficiency of the current common way (improving the material quality of the sealing ring and increasing the number) of improving the sealing performance of the sealing ring of the hydraulic layer packer, and improves the sealing effect and the service life of the packer by improving the hydraulic oil to deal with the problem after the failure of the sealing ring.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to a sealing ring aid material and its application. Background Technology

[0002] Offshore oilfields have long oil well sections and multiple small layers produced together. After long-term water injection, the degree of inter-layer interference has been further aggravated.

[0003] Offshore oilfield development primarily utilizes stratified injection-production technology. For example, Chinese invention patent application CN107448185A discloses a method for intensifying the placement of new wells in old offshore oilfield areas. This method includes: Step 1, determining the initial production limit and controlled reserves of a single well; Step 2, determining the economically reasonable well network density; Step 3, determining the method for subdividing and combining offshore reservoir strata; Step 4, determining the form of the offshore reservoir well network and the reasonable well spacing; Step 5, optimizing the location of new wells based on seismic data, platform location, and numerical simulations; Step 6, determining the stratification of new wells, the workload of measures for old wells, and refining the parameter tables for new and old wells. This method for intensifying the placement of new wells in old offshore oilfield areas has achieved significant improvements in oil production rate, reduced controlled reserves per well, and further improved the injection-production well network, resulting in good economic and social benefits.

[0004] Currently, the stratified injection and production technology used in offshore oilfields mainly employs packers for stratification. Sealing rings are a key component in stratification and are widely used in hydraulically controlled injection and production tools. However, when the sealing ring fails, the packer becomes ineffective, requiring well shutdown for packer replacement and necessitating restarts, thus disrupting normal production.

[0005] The 6th issue of *Petroleum Pipes & Instruments* in 2018 published an analysis of influencing factors and improvement measures for stratified pressure testing in water injection wells. The effectiveness and accuracy of the test data were ensured by verifying the packer seal before testing, adopting a new type of sealing ring, and modifying the pressure testing process. Addressing the issues of completely overlapping pressure curves and inaccurate or missing test data in stratified pressure testing of water injection wells, the internal structure of common packers in oilfields and the stratified pressure testing process were analyzed in depth. It was found that packer unsealing, pressure gauge seal damage, and inaccurate pressure gauge test data are important factors affecting stratified pressure testing. The effectiveness and accuracy of the test data were ensured by verifying the packer seal before testing, adopting a new type of sealing ring, and modifying the pressure testing process. Extensive field data analysis results show that the improved measures have increased the accuracy of stratified pressure testing data in field applications, reflecting more detailed geological conditions and providing important basis for adjusting dynamic oilfield production plans.

[0006] The October 2022 issue of "Internal Combustion Engine & Parts" published the reasons for the failure of "O" ring seals during the overall stratified pressure test of water injection wells. It provided guidance on applying appropriate injection pressure during the test to ensure the sealing performance of the "O" rings, thereby improving the success rate of stratified static pressure tests for water injection wells.

[0007] Interpretive static pressure data from water injection wells is crucial for determining the injection volume and pressure of injection zones. However, the failure of O-ring seals during the overall static pressure testing of water injection wells in Daqing Oilfield in recent years has led to inaccurate test data. This study explores the common failure modes and main causes of O-ring seals by examining their sealing mechanism, analyzes the problems in the overall testing process, and proposes countermeasures to maintain the sealing capacity of O-ring seals. Research shows that during the overall static pressure testing of water injection wells, the tubing pressure gradually decreases, causing the contact pressure of the O-ring seal to gradually approach the formation pressure being tested, which is the main reason why the O-ring seal completely loses its sealing capacity. Selecting the interlayer method for testing the static pressure of water injection wells and applying appropriate injection pressure during the test can ensure the sealing performance of the O-ring seal, thereby improving the success rate of the static pressure testing of water injection wells.

[0008] In summary, the current focus for handling seal failure is mainly on optimizing the seal material; there are currently no reports on improving sealing performance. Summary of the Invention

[0009] Purpose of the invention: In view of the shortcomings of the prior art, the present invention provides a sealing ring reinforcement material and its application, and in particular provides a sealing ring reinforcement material for use after the sealing ring of a hydraulic switch fails. The sealing ring reinforcement material disclosed in the present invention works when the sealing ring of a hydraulic switch fails, and it can be repeatedly injected for permanent reinforcement.

[0010] Technical solution: A sealing ring additive material, by weight, comprises the following components:

[0011] 30-100 parts hydraulic oil;

[0012] 0-5 parts oil-based thickener;

[0013] 5-25 parts of water-swellable agent;

[0014] 10-30 portions of propionate.

[0015] Furthermore, the viscosity grade of the hydraulic oil is one of 10, 15, 22, 32, 46, 68, 100, and 150.

[0016] Furthermore, the amount of hydraulic oil used is 40-80 parts, preferably 45-60 parts.

[0017] Furthermore, the oily thickener is one or more of the following: an oil-soluble stearate containing two or three long chains of stearic acid, a long-chain fatty acid glyceride, or an olefin polymer.

[0018] Furthermore, the olefin polymer is one or more of polystyrene, polyethylene, and polypropylene.

[0019] Furthermore, the long-chain fatty acid glyceride is a C12-C24 long-chain fatty acid glyceride, preferably glyceryl stearate.

[0020] Furthermore, the water-swellable agent is one or more of polyacrylamide, modified starch, and modified cellulose.

[0021] Furthermore, the particle size of the water-swellable agent is less than 0.5 mm.

[0022] Furthermore, the support agent is short fiber or partially hydrolyzed acrylic filament.

[0023] Furthermore, the short fiber is one or more of cotton-type short fibers and wool-type short fibers.

[0024] Furthermore, the partially hydrolyzed acrylic fiber is an alkaline partially hydrolyzed acrylic fiber with a degree of hydrolysis of 10%-50%, preferably an alkaline partially hydrolyzed acrylic fiber with a degree of hydrolysis of 20%-40%, and more preferably an alkaline partially hydrolyzed acrylic fiber with a degree of hydrolysis of 25%-35%.

[0025] The sealing ring additives described in any of the above-mentioned items are used as sealing ring additives in oil extraction.

[0026] Furthermore, the specific steps of the application are as follows:

[0027] (1) Add the hydraulic oil and oil-based thickener of the formula to the reaction vessel and stir evenly. Then add the water-swelling agent and the support agent of the formula and stir evenly to obtain the sealing ring auxiliary material.

[0028] (2) First, inject hydraulic oil to displace the water in the pipeline, and then inject the sealing ring sealing material into the hydraulic switch.

[0029] Furthermore, the injection amount of the sealing ring sealing material is 101%-120% of the total capacity of the hydraulic control pipeline where the hydraulic switch is located (that is, the injection amount of the sealing ring sealing material is slightly more than the total capacity of the hydraulic control pipeline where the hydraulic switch is located).

[0030] Invention principle: When the sealing ring has a poor sealing effect or is damaged and fails after long-term use, hydraulic oil is first injected to displace the water. There is no water in the packer and capillary tube, so it only works at the leak point. Then, sealing aid material is injected into the sealing ring. Under pressure, the water in the wellbore seeps into the sealing ring and encounters the sealing material. The sealing material expands when it comes into contact with water, forming a blockage and playing a role in sealing.

[0031] Beneficial effects: The sealing ring aid material and its application disclosed in this invention have the following beneficial effects:

[0032] To address the shortcomings of current methods for improving the sealing performance of hydraulic packers by modifying the sealing rings (by improving the material and increasing the number of sealing rings), this invention addresses the problem of sealing ring failure by improving the hydraulic oil, thereby improving the sealing effect and extending the service life of the packer. Detailed Implementation

[0033] The specific embodiments of the present invention are described in detail below.

[0034] Example 1

[0035] A sealing ring additive material, by weight, comprises the following components:

[0036] 30 parts hydraulic oil;

[0037] 5 parts of water-reactive swelling agent;

[0038] 10 portions of propionate.

[0039] Furthermore, the viscosity grade of the hydraulic oil is 68.

[0040] In another embodiment, the amount of hydraulic oil used is 40 parts. In another embodiment, the amount of hydraulic oil used is 45 parts.

[0041] Furthermore, the water-swellable agent is polyacrylamide.

[0042] Furthermore, the particle size of the water-swellable agent is less than 0.5 mm.

[0043] Furthermore, the support agent is short fiber.

[0044] Furthermore, the short fibers are cotton-type short fibers (commonly known as "artificial cotton"). In another embodiment, the short fibers are wool-type short fibers (commonly known as "artificial wool"). In yet another embodiment, the short fibers are a mixture of cotton-type short fibers and wool-type short fibers in equal mass ratios.

[0045] The aforementioned sealing ring additives are used as sealing ring additives in oil extraction.

[0046] Furthermore, the specific steps of the application are as follows:

[0047] (1) Add the hydraulic oil and oil-based thickener of the formula to the reaction vessel and stir evenly. Then add the water-swelling agent and the support agent of the formula and stir evenly to obtain the sealing ring auxiliary material.

[0048] (2) First, inject hydraulic oil to displace the water in the pipeline, and then inject the sealing ring sealing material into the hydraulic switch.

[0049] Furthermore, the amount of sealing ring additive material injected is 101% of the total capacity of the hydraulic pipeline where the hydraulic switch is located.

[0050] In Shengli Oilfield, a hydraulic control pipeline A was compromised by poor sealing of its sealing rings, or by damage and failure of the sealing rings due to long-term use, allowing water to seep into the pipeline. Pressurization was impossible. However, after injecting the sealing ring enhancement material prepared in Example 1 using the method described above, hydraulic control pipeline A was able to withstand a pressure of 30 MPa, achieving a better sealing effect.

[0051] Example 2

[0052] A sealing ring additive material, by weight, comprises the following components:

[0053] 100 parts hydraulic oil;

[0054] 5 parts oil-based thickener;

[0055] 25 parts of water-reactive swelling agent;

[0056] 30 portions of propionate.

[0057] Furthermore, the viscosity grade of the hydraulic oil is 15.

[0058] In another embodiment, the amount of hydraulic oil used is 80 parts. In another embodiment, the amount of hydraulic oil used is 60 parts.

[0059] Furthermore, the oily thickener is a mixture of oil-soluble stearate containing two long chains of stearic acid, long-chain fatty acid glycerides, and olefin polymers in equal mass ratios.

[0060] Furthermore, the olefin polymer is polystyrene. In another embodiment, the olefin polymer is polyethylene. In another embodiment, the olefin polymer is polypropylene. In yet another embodiment, the olefin polymer is a mixture of polystyrene, polyethylene, and polypropylene in equal mass ratios.

[0061] Furthermore, the long-chain fatty acid glyceride is glyceryl stearate. In another embodiment, the long-chain fatty acid glyceride is a C12 long-chain fatty acid glyceride. In another embodiment, the long-chain fatty acid glyceride is a C24 long-chain fatty acid glyceride. In yet another embodiment, the long-chain fatty acid glyceride is a C16 long-chain fatty acid glyceride.

[0062] Further, the water-reactive swelling agent is modified starch. In another embodiment, the water-reactive swelling agent is modified cellulose. In yet another embodiment, the water-reactive swelling agent is a mixture of polyacrylamide, modified starch, and modified cellulose in equal mass ratios.

[0063] Furthermore, the particle size of the water-swellable agent is less than 0.5 mm.

[0064] Furthermore, the support agent is partially hydrolyzed acrylic fiber.

[0065] Furthermore, the partially hydrolyzed acrylic fiber is an alkaline partially hydrolyzed acrylic fiber with a degree of hydrolysis of 10%.

[0066] In another embodiment, the partially hydrolyzed acrylic filament is an alkaline partially hydrolyzed acrylic filament with a degree of hydrolysis of 20%. In another embodiment, the partially hydrolyzed acrylic filament is an alkaline partially hydrolyzed acrylic filament with a degree of hydrolysis of 25%.

[0067] The aforementioned sealing ring additives are used as sealing ring additives in oil extraction.

[0068] Furthermore, the specific steps of the application are as follows:

[0069] (1) Add the hydraulic oil and oil-based thickener of the formula to the reaction vessel and stir evenly. Then add the water-swelling agent and the support agent of the formula and stir evenly to obtain the sealing ring auxiliary material.

[0070] (2) First, inject hydraulic oil to displace the water in the pipeline, and then inject the sealing ring sealing material into the hydraulic switch.

[0071] Furthermore, the amount of sealing ring additive material injected is 120% of the total capacity of the hydraulic pipeline where the hydraulic switch is located.

[0072] In Shengli Oilfield, water seeped into hydraulic control pipeline B due to poor sealing performance or damage to the sealing rings from long-term use. Pressurization was impossible. However, after injecting the sealing ring aid material prepared in Example 2 using the method described above, hydraulic control pipeline B could withstand a pressure of 40 MPa, achieving a better sealing effect.

[0073] Example 3

[0074] A sealing ring additive material, by weight, comprises the following components:

[0075] 55 parts hydraulic oil;

[0076] 2 parts oil-based thickener;

[0077] 15 parts of water-reactive swelling agent;

[0078] 20 portions of propionate.

[0079] Further, the viscosity grade of the hydraulic oil is 46. In another embodiment, the viscosity grade of the hydraulic oil is 32. In another embodiment, the viscosity grade of the hydraulic oil is 22. In another embodiment, the viscosity grade of the hydraulic oil is 10. In another embodiment, the viscosity grade of the hydraulic oil is 100. In another embodiment, the viscosity grade of the hydraulic oil is 150.

[0080] Furthermore, the oily thickener is an oil-soluble stearate containing three long chains of stearic acid.

[0081] In another embodiment, the oily thickener is a long-chain fatty acid glyceride. In yet another embodiment, the oily thickener is an olefin polymer.

[0082] Furthermore, the olefin polymer is polystyrene.

[0083] Furthermore, the long-chain fatty acid glyceride is a stearic acid glyceride.

[0084] Furthermore, the water-swellable agent is polyacrylamide.

[0085] Furthermore, the particle size of the water-swellable agent is less than 0.5 mm.

[0086] Furthermore, the support agent is partially hydrolyzed acrylic fiber.

[0087] Furthermore, the partially hydrolyzed acrylic fiber is an alkaline partially hydrolyzed acrylic fiber with a degree of hydrolysis of 50%.

[0088] In another embodiment, the partially hydrolyzed acrylic filament is an alkaline partially hydrolyzed acrylic filament with a degree of hydrolysis of 40%. In another embodiment, the partially hydrolyzed acrylic filament is an alkaline partially hydrolyzed acrylic filament with a degree of hydrolysis of 35%.

[0089] The aforementioned sealing ring additives are used as sealing ring additives in oil extraction.

[0090] Furthermore, the specific steps of the application are as follows:

[0091] (1) Add the hydraulic oil and oil-based thickener of the formula to the reaction vessel and stir evenly. Then add the water-swelling agent and the support agent of the formula and stir evenly to obtain the sealing ring auxiliary material.

[0092] (2) First, inject hydraulic oil to displace the water in the pipeline, and then inject the sealing ring auxiliary material into the hydraulic switch.

[0093] Furthermore, the amount of sealing ring additive material injected is 105% of the total capacity of the hydraulic pipeline where the hydraulic switch is located.

[0094] In a hydraulic control pipeline C at Shengli Oilfield, water seeped into the pipeline due to poor sealing performance or damage to the sealing ring caused by long-term use. Pressurization was impossible. However, after injecting the sealing ring aid material prepared in Example 3 using the method described above, hydraulic control pipeline C could withstand a pressure of 40 MPa, achieving a better sealing effect.

[0095] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. The application of a sealing ring additive material as a sealing ring additive in oil extraction, characterized in that, When the sealing ring of the hydraulic switch fails, the sealing ring reinforcement material is injected into the hydraulic switch. This reinforcement material functions when the sealing ring fails and can be repeatedly injected for permanent reinforcement. Specifically: The sealing ring additive material, by weight, is composed of the following components: 30-100 parts hydraulic oil; 0-5 parts oil-based thickener; 5-25 parts of water-swellable agent; 10-30 parts of propionate, of which: The oily thickener is one or more of the following: oil-soluble stearate containing two or three long chains of stearic acid, long-chain fatty acid glycerides, and olefin polymers. The water-swellable agent is one or more of polyacrylamide, modified starch, and modified cellulose.

2. The application as described in claim 1, characterized in that, The viscosity grade of the hydraulic oil is one of 10, 15, 22, 32, 46, 68, 100, or 150.

3. The application as described in claim 1, characterized in that, The amount of hydraulic oil used is 40-80 parts.

4. The application as described in claim 3, characterized in that, The amount of hydraulic oil used is 45-60 parts.

5. The application as described in claim 1, characterized in that, The olefin polymer is one or more of polystyrene, polyethylene, and polypropylene.

6. The application as described in claim 1, characterized in that, The long-chain fatty acid glycerides are C12-C24 long-chain fatty acid glycerides.

7. The application as described in claim 6, characterized in that, The long-chain fatty acid glyceride is stearic acid glyceride.

8. The application as described in claim 1, characterized in that, The particle size of the water-swellable agent is less than 0.5 mm.

9. The application as described in claim 1, characterized in that, The support is short fiber or partially hydrolyzed acrylic fiber.

10. The application as described in claim 9, characterized in that, The short fibers are one or more of cotton-type short fibers and wool-type short fibers.

11. The application as described in claim 9, characterized in that, The partially hydrolyzed acrylic fiber is an alkaline partially hydrolyzed acrylic fiber with a degree of hydrolysis of 10%-50%.

12. The application as described in claim 11, characterized in that, The partially hydrolyzed acrylic fiber is an alkaline partially hydrolyzed acrylic fiber with a degree of hydrolysis of 20%-40%.

13. The application as described in claim 12, characterized in that, The partially hydrolyzed acrylic fiber is an alkaline partially hydrolyzed acrylic fiber with a degree of hydrolysis of 25%-35%.

14. The application as described in claim 1, characterized in that, The specific steps of the application are as follows: (1) Add the hydraulic oil and oil-based thickener of the formula to the reaction vessel and stir evenly. Then add the water-swelling agent and the proppant of the formula and stir evenly to obtain the sealing ring auxiliary material. (2) First, inject hydraulic oil to displace the water in the pipeline, and then inject the sealing ring auxiliary material into the hydraulic switch.

15. The application as described in claim 14, characterized in that, The amount of sealing ring additive material injected is 101%-120% of the total capacity of the hydraulic pipeline where the hydraulic switch is located.