Detection device and detection method for plugging performance of plugging agent

Abstract

The invention relates to the technical field of oil field plugging testing, and provides a device and method for detecting the plugging performance of a plugging agent, the device for detecting the plugging performance of the plugging agent comprises an injection molding section, a test section, an extrusion bolt and an adjusting cavity section, the injection molding section is communicated with a pressure pipe, and the extrusion bolt is slidably connected into the injection molding section; the test section is detachably connected with the end, away from the pressure pipe, of the injection molding section, the plugging agent can be extruded by the extrusion bolt to penetrate through the passing seam to enter the test section, the test section is used for detecting the performance of the plugging agent, the adjusting cavity section is detachably connected to the end, away from the injection molding section, of the test section, and the adjusting cavity section, the test section and the injection molding section are communicated. The extrusion bolt can slide in the injection molding section, the test section and the adjusting cavity section, the test section is internally provided with an annular cavity, the annular cavity is filled with sand grains, and the technical problem that the actual in-well environment is difficult to simulate when the performance of the plugging agent is detected in the related technology is solved.

Description

Technical Field

[0001] This invention relates to the field of oilfield plugging testing technology, specifically to a testing device and method for testing the plugging performance of plugging agents. Background Technology

[0002] When drilling in an oil field, if the amount of drilling fluid pumped into the well is greater than the amount returned, it can be directly judged that a leak has occurred in the well, the drilling fluid has been absorbed by the formation, or there are situations such as a drop in pump pressure or a drop in drilling fluid level. At this time, it is necessary to use a plugging agent to seal the leak in the rock formation. The plugging agent enters the cracks between the rock or sand grains and solidifies to seal the leak. In order to ensure the performance of the plugging agent, it is necessary to test it.

[0003] Existing technologies for testing plugging agents involve setting up a cylindrical container, placing sand at the bottom, compacting the sand, adding the plugging agent, and then squeezing the agent. The plugging agent is then forced into the sand and binds to it. Under a certain pressure, the sand solidifies under the action of the plugging agent. The pressure resistance of the plugging agent is tested by measuring the force of the sand being squeezed, and the flowability of the plugging agent is tested by observing the depth of penetration into the sand. However, in actual drilling, leaks often occur on the wellbore or casing wall, and the plugging agent flows into the sand through cracks in the wellbore. This differs from the environment simulated by experimental equipment, making it difficult to accurately assess the actual plugging performance of the plugging agent in the well. Summary of the Invention

[0004] To overcome the above-mentioned defects, embodiments of the present invention provide a testing device and method for detecting the plugging performance of plugging agents, which solves the technical problem in the related art of simulating the working conditions of plugging agents in the actual well environment.

[0005] At least one embodiment of the present invention provides a testing device for the sealing performance of a plugging agent, comprising a protective cover, a support, and a pressure tube. The support and the pressure tube are disposed within the protective cover. The device further comprises an injection section, a test section, a squeeze plug, and an adjustment cavity. The injection section is connected to the pressure tube and is hollow, with a squeeze plug slidably connected inside. The test section is detachably connected to the end of the injection section away from the pressure tube. Multiple circumferentially arranged through-slits are provided on the inner wall of the test section, allowing the plugging agent to pass through the through-slits and enter the test section under the pressure of the squeeze plug. The test section is used to test the performance of the plugging agent. The adjustment cavity is detachably connected to the end of the test section away from the injection section. The adjustment cavity, the test section, and the injection section are connected. The squeeze plug can slide within the injection section, the test section, and the adjustment cavity. The test section contains an annular cavity filled with sand particles. The through-slits are connected to the annular cavity.

[0006] The extrusion bolt is equipped with an extrusion section and a limiting disc. The limiting disc has multiple through holes and is located on the side near the pressure tube. The limiting disc can slide within the injection section. The extrusion section can extend into the test section and the adjustment chamber section. When the extrusion section slides into the test section, it fits against the inner wall of the test section and contacts the through seam. The connection between the limiting disc and the extrusion section has a smaller diameter, and a gap exists between it and the inner cylinder during sliding, allowing gas flow.

[0007] The test section includes an outer cylinder and an inner cylinder. The injection section and the adjustment cavity section are detachably connected to both ends of the outer cylinder, and the inner cylinder is detachably connected to the outer cylinder. A through-slit is formed on the inner cylinder, and an annular cavity exists between the inner cylinder and the outer cylinder. Multiple stabilizing strips are fixedly connected to one side of the inner cylinder near the annular cavity. These stabilizing strips extend into the sand particles, allowing the sealant to come into contact with them when it mixes with the sand particles through the through-slit. The stabilizing strips increase the rigidity of the sealant-adhered sand particles, facilitating the removal of unadhered sand particles after the outer cylinder is removed, and allowing for observation of the shape of the adhered sand particles.

[0008] The adjusting cavity section includes an adjusting cavity body and a receiving plate. The adjusting cavity body is detachably connected to the outer cylinder. The interior of the adjusting cavity body is connected to the inner cylinder. The extrusion section can extend into the adjusting cavity body. The receiving plate is slidably connected in the adjusting cavity body. The extrusion section can be in contact with the receiving plate. A spring is provided between the receiving plate and the adjusting cavity body.

[0009] Multiple limiting pins are slidably connected to the adjusting cavity. These limiting pins are detachably connected to the receiving plate. When the receiving plate slides within the adjusting cavity to a position close to the test section, the limiting pins can fix and limit its movement. When the extrusion section contacts the receiving plate, it is located within the inner cylinder. A driving device can be installed on the bracket or adjusting cavity to drive the limiting pins to slide. After the extrusion section contacts the receiving plate, the limiting pins can slide away from the extrusion section. At this point, under pressure, the extrusion section pushes the receiving plate and the spring, causing the extrusion section to separate from the inner cylinder.

[0010] When the extrusion section slides into the adjustment cavity, the injection section connects to the through-hole and the through-slit. At this time, the liquid or gas pressure delivered by the pressure pipe directly acts on the through-slit, pushing the sealing agent and directly detecting the pressure that the sealing agent can withstand.

[0011] A method for testing the sealing performance of a plugging agent, based on the aforementioned testing device for the sealing performance of a plugging agent, includes the following steps: Step 1: Device assembly: Connect the injection section, the outer cylinder, and the adjustment chamber in sequence, and place them on the support; Step 2: Filling with sealant: After filling the inner cylinder with sealant, insert the extrusion plug into the injection section and align the extrusion section with the inner cylinder; Step 3, Pressure Testing: The pressure tube increases the pressure into the injection section, pushing the extrusion section to slide in the inner cylinder. The extrusion section squeezes the sealing agent through the through-slit into the annular cavity, where it comes into contact with the sand particles. Step 4, Sampling and Testing: Separating the inner cylinder from the outer cylinder reveals sand particles on the inner cylinder that have been penetrated and solidified by the sealing agent.

[0012] This invention provides a testing device and method for detecting the sealing performance of a plugging agent. Compared with existing technologies, this invention uses a cylindrical test section. By sliding a compression plug, the plugging agent is pushed into the test section. Sand particles are filled into an annular cavity to simulate the actual downhole environment. The plugging agent is pushed in by the compression plug. The solidified sand particle sample in the annular cavity of the test section can provide a more intuitive judgment on the adhesion and solidification ability of the plugging agent to the sand particles. Existing equipment mostly simulates the solidification ability by placing columnar sand particles in the testing device to penetrate the plugging agent. This invention provides a more intuitive judgment. At the same time, pressure can be applied to the plugging agent by injecting liquid in the pressure pipe to further simulate the pressure on the well wall during oil extraction in the downhole environment. This is a simulation effect that traditional experimental methods cannot provide. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the overall structure of a device for testing the sealing performance of a plugging agent according to one embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the protective cover of the present invention; Figure 3 This is a cross-sectional internal structural diagram showing the cooperation between the pledging section and the test section in this invention; Figure 4 This is a cross-sectional internal structural diagram showing the combination of the injection section, the test section, and the adjustment cavity section in this invention; Figure 5This is a partial cross-sectional internal structural diagram showing the combination of the injection section, test section, and adjustment cavity section in this invention; Figure 6 This is a partial cross-sectional view of the internal structure of the limiting pin and the receiving plate in this invention.

[0015] In the diagram: 1. Protective cover; 2. Bracket; 3. Pressure pipe; 4. Injection section; 5. Extrusion bolt; 6. Extrusion section; 7. Limiting plate; 8. Through hole; 9. Through slot; 10. Outer cylinder; 11. Inner cylinder; 12. Stabilizing bar; 13. Adjusting cavity; 14. Receiving plate; 15. Spring; 16. Limiting pin. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0017] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0018] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0019] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those illustrated or described herein.

[0020] To make the drawings concise and easy to understand, some drawings only show one of the components with the same structure or function, or only one of them is marked. In this article, "one" not only means "only one", but can also mean "more than one", and "several" includes "two" and "more than two".

[0021] Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. The embodiments of this application are described in detail below with reference to the accompanying drawings.

[0022] Example 1 like Figures 1-6 The diagram illustrates a testing device for the sealing performance of a plugging agent according to an embodiment of the present invention. It includes a protective cover 1, a support 2, and a pressure tube 3. The support 2 and pressure tube 3 are disposed inside the protective cover 1. The device also includes an injection section 4, a test section, a squeeze plug 5, and an adjustment chamber. The injection section 4 is hollow and connected to the pressure tube 3, with the squeeze plug 5 slidably connected inside. The test section is detachably connected to the end of the injection section 4 furthest from the pressure tube 3. Multiple circumferential through-slits 9 are arranged on the inner wall of the test section, allowing the plugging agent to pass through the through-slits 9 under the pressure of the squeeze plug 5 and enter the test section. The test section is used to test the performance of the plugging agent. The test section is detachably connected to the end of the test section away from the injection section 4. The test section, the test section, and the injection section 4 are connected. The squeeze plug 5 can slide in the injection section 4, the test section, and the test section. The test section is set with an annular cavity filled with sand particles, which is connected to the annular cavity through the slot 9. This application simulates the downhole environment by setting an annular test section. The squeeze plug 5 squeezes the plugging agent into the annular cavity of the test section to simulate the situation where the plugging agent enters the sandstone layer through the well wall gap. At the same time, the actual diffusion depth of the plugging agent in the sand particles can be detected by taking out the solidified sand particles in the test section.

[0023] like Figures 3-5As shown, the compression bolt 5 is equipped with a compression section 6 and a limiting disc 7. The limiting disc 7 has multiple through holes 8 and is located on the side near the pressure tube 3. The limiting disc 7 can slide in the injection section 4. The compression section 6 can extend into the test section and the adjustment chamber section. When the compression section 6 slides into the test section, it fits against the inner wall of the test section and can contact the through seam 9. The connecting part between the limiting disc 7 and the compression section 6 has a smaller diameter and a gap exists between it and the inner cylinder 11 when sliding, allowing gas to flow. The limiting disc 7 has a larger diameter and cannot enter the inner cylinder 11. When the compression section 6 slides into the adjustment chamber 13, the limiting disc 7 limits the compression bolt 5 in the injection section 4.

[0024] like Figures 3-5 As shown, the test section includes an outer cylinder 10 and an inner cylinder 11. The injection section 4 and the adjustment chamber section are detachably connected to both ends of the outer cylinder 10. The inner cylinder 11 is detachably connected to the outer cylinder 10 and is opened on the inner cylinder 11 through the seam 9. There is an annular cavity between the inner cylinder 11 and the outer cylinder 10. Multiple stabilizing strips 12 are fixedly connected to one side of the inner cylinder 11 near the annular cavity. The stabilizing strips 12 extend into the sand particles. When the sealant mixes with the sand particles through the seam 9, it can also come into contact with the stabilizing strips 12. The stabilizing strips 12 can increase the rigidity of the sand particles that are adhered to by the sealant, so that the unadhered sand particles can be lost after the outer cylinder 10 is removed. The shape of the adhered sand particles can be observed. The stabilizing strips 12 are in contact with the sealant and adhere to the sand particles, thereby achieving the effect of preventing the sand particle layer from breaking. After the outer cylinder 10 is separated from the inner cylinder 11, the sand particles can still be attached to the inner cylinder 11. The actual effect of sand particle fixation can be observed intuitively. Scales can be set on the stabilizing strips 12 for easy observation.

[0025] like Figures 3-6As shown, the adjustment cavity section includes an adjustment cavity 13 and a receiving plate 14. The adjustment cavity 13 is detachably connected to the outer cylinder 10. The interior of the adjustment cavity 13 is connected to the inner cylinder 11. The extrusion section 6 can extend into the adjustment cavity 13. The receiving plate 14 is slidably connected in the adjustment cavity 13. The extrusion section 6 can be in contact with the receiving plate 14. A spring 15 is provided between the receiving plate 14 and the adjustment cavity 13. Multiple limiting pins 16 are slidably connected on the adjustment cavity 13. The limiting pins 16 are detachably connected to the receiving plate 14. When the receiving plate 14 slides in the adjustment cavity 13 to one end close to the test section, the limiting pins 16 can limit and fix the receiving plate 14. When the extrusion section 6 contacts the receiving plate 14, the extrusion section 6 is located in the inner cylinder 11. A drive device can be installed on the bracket 2 or the adjusting cavity 13 to drive the limiting pin 16 to slide. When the extrusion section 6 contacts the receiving plate 14, the limiting pin 16 can slide and separate from the extrusion section 6. At this time, the extrusion section 6 pushes the receiving plate 14 and the spring 15 under pressure, so that the extrusion section 6 separates from the inner cylinder 11. When the limiting pin 16 is used to fix the receiving plate 14, the squeezing section 6 is squeezed by the pressure of the liquid or gas introduced into the pressure pipe 3, so that the squeezing section 6 pushes the plugging agent between the squeezing section 6 and the receiving plate 14 to flow into the through-slit 9. When the plugging agent cannot be squeezed into the through-slit 9, after the pressure stabilizes, the pressure in the pressure pipe 3 at this time can be detected to be the pressure received by the plugging agent at the through-slit 9. Depending on the simulation situation, it can be set to push all the plugging agent into the through-slit 9 and then slide the limiting pin 16. At this time, the squeezing section 6 pushes the receiving plate 14 and the spring 15 is compressed. When the squeezing section 6 enters the regulating cavity 13, the liquid or gas introduced into the pressure pipe 3 can enter the inner cylinder 11 through the through hole 8 and directly apply pressure to the through-slit 9 to simulate the actual pressure on the well wall when downhole.

[0026] like Figures 3-6 As shown, when the extrusion section 6 slides into the adjustment cavity 13, the injection section 4 is connected to the through-hole 8 and the through-slit 9. At this time, the liquid pressure or gas pressure delivered by the pressure pipe 3 directly acts on the through-slit 9, pushing the sealing agent and directly detecting the pressure that the sealing agent can withstand.

[0027] In this embodiment, an inner cylinder 11 and an outer cylinder 10 are combined to form a test section, constituting an annular cavity. Then, the compression plug 5 moves under pressure to push the plugging agent through the slot 9 into the annular cavity to combine with the sand particles, simulating the downhole environment for plugging. At the same time, the sliding distance of the compression plug 5 can be limited by adjusting the cavity 13 and the limiting pin 16. This allows for actual testing of the pressure that the plugging agent can withstand by adjusting the two methods of directly squeezing the plugging agent or squeezing through the slot 9 with other media, based on experimental conditions. This provides a more intuitive simulation of the downhole environment. In addition, the penetration depth and diffusion shape of the plugging agent into the sand particles attached to the outer wall of the inner cylinder 11 can be directly detected.

[0028] Example 2 A method for testing the sealing performance of a plugging agent, based on the aforementioned testing device for the sealing performance of a plugging agent, includes the following steps: Step 1: Assembly of the device: Connect the injection section 4, the outer cylinder 10 and the adjusting cavity 13 in sequence and place them on the support 2; Step 2: Filling the sealing agent: After filling the sealing agent into the inner cylinder 11, insert the squeeze plug 5 into the injection section 4 and align the squeeze section 6 with the inner cylinder 11; Step 3, Pressure test: Pressure pipe 3 increases pressure into injection section 4, pushing extrusion section 6 to slide in inner cylinder 11. Extrusion section 6 extrudes the sealing agent through through seam 9 into the annular cavity, where it comes into contact with the sand particles. Step 4, Sampling and Testing: Separate the inner cylinder 11 from the outer cylinder 10 to obtain the sand particles on the inner cylinder 11 that have been penetrated and solidified by the sealing agent.

[0029] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A testing device for the sealing performance of a plugging agent, comprising a protective cover (1), a support (2), and a pressure tube (3), wherein the support (2) and the pressure tube (3) are disposed within the protective cover (1), characterized in that, Also includes: The injection section (4) is connected to the pressure tube (3), and is hollow with a squeezing bolt (5) slidingly connected inside. The test section is detachably connected to the end of the injection section (4) away from the pressure tube (3). The inner wall of the test section is provided with multiple through slots (9) in a circular pattern. The sealant can be squeezed by the squeeze plug (5) and pass through the through slots (9) into the test section. The test section is used to test the performance of the sealant. An adjustment cavity is detachably connected to the end of the test section away from the injection section (4). The adjustment cavity, the test section and the injection section (4) are connected. The squeeze plug (5) can slide in the injection section (4), the test section and the adjustment cavity. The test section is configured as an annular cavity, which is filled with sand particles, and the through-slit (9) is connected to the annular cavity.

2. The testing device for the sealing performance of a plugging agent according to claim 1, characterized in that, The compression plug (5) is provided with a compression section (6) and a limiting plate (7). The limiting plate (7) has multiple through holes (8). The limiting plate (7) is located on the side close to the pressure tube (3). The limiting plate (7) can slide in the injection section (4). The compression section (6) can extend into the test section and the adjustment cavity section.

3. The testing device for the sealing performance of a plugging agent according to claim 2, characterized in that, When the extrusion section (6) slides into the test section, it fits against the inner wall of the test section and can come into contact with the through-slit (9).

4. The testing device for the sealing performance of a plugging agent according to claim 3, characterized in that, The test section includes: The outer cylinder (10), the injection section (4) and the adjustment chamber section are detachably connected to both ends of the outer cylinder (10); The inner cylinder (11) is detachably connected to the outer cylinder (10), and the through slit (9) is opened on the inner cylinder (11). There is an annular cavity between the inner cylinder (11) and the outer cylinder (10).

5. The testing device for the sealing performance of a plugging agent according to claim 4, characterized in that, Multiple stabilizing strips (12) are fixedly connected to the inner cylinder (11) near the annular cavity. The stabilizing strips (12) extend into the sand particles. When the sealing agent mixes with the sand particles through the through-slit (9), it can also come into contact with the stabilizing strips (12).

6. The testing device for the sealing performance of a plugging agent according to claim 5, characterized in that, The regulating cavity includes: The adjusting cavity (13) is detachably connected to the outer cylinder (10), and the interior of the adjusting cavity (13) is connected to the inner cylinder (11). The extrusion section (6) can extend into the adjusting cavity (13). The receiving plate (14) is slidably connected in the adjusting cavity (13), the extrusion section (6) can be connected to the receiving plate (14), and a spring (15) is provided between the receiving plate (14) and the adjusting cavity (13).

7. The testing device for the sealing performance of a plugging agent according to claim 6, characterized in that, Multiple limiting pins (16) are slidably connected to the adjustment cavity (13). The limiting pins (16) are detachably connected to the receiving plate (14). When the receiving plate (14) slides in the adjustment cavity (13) to one end close to the test section, the limiting pins (16) can limit and fix the receiving plate (14).

8. The testing device for the sealing performance of a plugging agent according to claim 7, characterized in that, When the extrusion section (6) comes into contact with the receiving plate (14), the extrusion section (6) is located in the inner cylinder (11).

9. A testing device for the sealing performance of a plugging agent according to claim 8, characterized in that, When the extrusion section (6) slides into the adjustment cavity (13), the injection section (4) is connected to the through hole (8) and the through slot (9).

10. A method for testing the sealing performance of a plugging agent, and a device for testing the sealing performance of a plugging agent according to claim 9, characterized in that, Includes the following steps: S1. Device assembly: Connect the injection section (4), the outer cylinder (10) and the adjustment cavity (13) in sequence and place them on the support (2); S2. Filling with sealant: After filling the sealant into the inner cylinder (11), insert the squeeze plug (5) into the injection section (4) and align the squeeze section (6) with the inner cylinder (11); S3, Pressure test: The pressure tube (3) increases the pressure in the injection section (4), pushing the extrusion section (6) to slide in the inner cylinder (11). The extrusion section (6) squeezes the sealing agent through the through-slit (9) into the annular cavity, where it comes into contact with the sand particles. S4. Sampling and testing: Separating the inner cylinder (11) from the outer cylinder (10) allows the collection of sand particles on the inner cylinder (11) that have been penetrated and solidified by the sealing agent.

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