Wellhead bidirectional dynamic seal compensator applied to shallow well formation test and shallow well formation test system

Abstract

The utility model relates to a wellhead two-way dynamic seal compensator applied to shallow well formation testing and a shallow well formation testing system. The wellhead two-way dynamic seal compensator comprises three core assemblies including a first connecting module, a second connecting module and a sealing module. The barrel and the second connecting module are arranged to be of a sliding connection structure, so that when wellhead equipment is subjected to temperature change, pressure fluctuation or mechanical vibration, the distance between the first connecting piece and the second connecting piece which are connected to the two ends of the wellhead bidirectional dynamic seal compensator is changed; the second connecting module connected with the second connecting piece can be compressed or stretched relative to the cylinder body, so that the distance between the first connecting piece and the second connecting piece is subjected to bidirectional compensation; therefore, the technical problems that in the prior art, due to the fact that the suspension distance between an oil pipe hanger and a casing pipe four-way joint is large, stability of testing operation is poor, and reliability is low are solved.

Description

Technical Field

[0001] This utility model relates to the field of oil drilling equipment technology, and in particular to a bidirectional dynamic seal compensator for wellhead and a shallow well formation testing system for use in shallow well formation testing. Background Technology

[0002] With the continuous development of shallow well formation testing technology, conventional expansion joints, as key downhole tools, directly affect the safety and reliability of testing operations. Conventional expansion joints mainly consist of a tubing connection structure and a sealing compensation mechanism, among which compression margin adjustment and dynamic sealing performance are core technical indicators for ensuring wellhead safety.

[0003] Currently, existing compensators can only achieve unidirectional compensation structures, and their stroke adjustment accuracy is low. This results in a large clearance between the tubing hanger and the casing four-way valve, which can easily lead to thread loosening accidents and seriously affect the stability and reliability of testing operations. Utility Model Content

[0004] This invention provides a bidirectional dynamic sealing compensator for wellheads used in shallow well formation testing, which solves at least one of the aforementioned technical problems.

[0005] In a first aspect, this utility model provides a bidirectional dynamic seal compensator for wellheads used in shallow well formation testing, comprising:

[0006] A first connecting module, the first connecting module including a female buckle, the female buckle being used to connect with a first connecting member;

[0007] The second connecting module includes a male buckle for connecting with the second connecting piece;

[0008] A sealing module includes a cylinder, a first sealing component, and a second sealing component. One end of the cylinder is fixedly connected to the first connecting module. The first sealing component is disposed between the first connecting module and the cylinder. The other end of the cylinder is slidably connected to the second connecting module. The second connecting module can extend or retract into the cylinder. The second sealing component is disposed between the cylinder and the second connecting module.

[0009] In one embodiment, the first connecting module is provided with a first annular sealing groove, and the first sealing assembly includes a first support ring and a first sealing ring, wherein the first support ring and the first sealing ring are fitted inside the first annular sealing groove.

[0010] In one embodiment, the first connecting module further includes a connecting part, which is inserted into the cylinder. The connecting part has a screw positioning groove, and the cylinder has a corresponding positioning hole. The screw passes through the positioning hole and is screwed into the screw positioning groove, so that the first connecting module is fixedly connected to the cylinder.

[0011] In one embodiment, the first connection module further includes a plug-in portion, the plug-in portion having a plug-in groove, and a guide groove being provided on the side of the plug-in groove away from the cylinder.

[0012] In one embodiment, the second connecting module further includes a mandrel, which is inserted into the cylinder and slidably connected to the cylinder. An annular limiting protrusion is provided at one end of the mandrel near the cylinder, and an annular limiting step is provided inside the cylinder. The annular limiting protrusion can engage with the annular limiting step.

[0013] In one embodiment, the mandrel is provided with a second annular sealing groove and a third annular sealing groove. The second sealing assembly includes a second support ring and a second sealing ring, which are fitted inside the second annular sealing groove. The sealing module further includes a third sealing assembly, which includes a third support ring and a third sealing ring, which are fitted inside the third annular sealing groove.

[0014] In one embodiment, the outer cross-section of the mandrel is square, and the inner side of the cylinder is configured to be square to match the outer side of the mandrel.

[0015] In one embodiment, the end of the mandrel away from the cylinder is provided with a guide portion, and the cross-section of the guide portion is tapered. In one embodiment, the relative sliding stroke between the mandrel and the cylinder is greater than or equal to 500 mm.

[0016] Secondly, this utility model also provides a shallow well formation testing system, including the above-mentioned wellhead bidirectional dynamic seal compensator, and a wellhead device including a casing four-way connector and a tubing hanger; a test string, which is suspended in the wellbore by the tubing hanger, the first connecting module being fixedly connected to the wellhead device, and the second connecting module being connected to the test string.

[0017] Compared with existing technologies, this utility model has the following significant advantages: This application provides a bidirectional dynamic sealing compensator for shallow well formation testing and a shallow well formation testing system, comprising three core components: a first connecting module, a second connecting module, and a sealing module. The sealing module includes a cylinder, a first sealing component, and a second sealing component. By setting the cylinder and the second connecting module as a sliding connection structure, when the wellhead equipment experiences temperature changes, pressure fluctuations, or mechanical vibrations, the gap between the first and second connecting parts connected at both ends of the bidirectional dynamic sealing compensator changes. The second connecting module, connected to the second connecting part, can be compressed or stretched relative to the cylinder to achieve bidirectional compensation for the gap between the first and second connecting parts. This solves the technical problem of poor testing stability and low reliability caused by the large clearance between the tubing hanger and the casing four-way valve in traditional technologies. Furthermore, the coordinated operation of the first and second sealing components forms a dual sealing guarantee mechanism, significantly improving the overall sealing performance and preventing safety hazards caused by compensator leakage. Attached Figure Description

[0018] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings.

[0019] Figure 1 This is a structural schematic diagram of a wellhead bidirectional dynamic sealing compensator provided in some embodiments of this application.

[0020] Figure 2 yes Figure 1 Cross-sectional view at point AA.

[0021] Figure label:

[0022] 1. First connecting module; 2. Sealing module; 3. Mandrel; 4. Support ring; 5. Sealing ring; 6. Positioning groove. Detailed Implementation

[0023] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0024] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are 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, and therefore should not be construed as a limitation of this application.

[0025] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0027] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0028] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] Firstly, see Figures 1-2 An embodiment of this application provides a bidirectional dynamic sealing compensator for shallow well formation testing, comprising a first connecting module 1, a second connecting module, and a sealing module 2; the first connecting module 1 includes a female thread for connecting to a first connecting member; the second connecting module includes a male thread for connecting to a second connecting member; the sealing module 2 includes a cylinder, a first sealing component, and a second sealing component, one end of the cylinder being fixedly connected to the first connecting module 1, the first sealing component being disposed between the first connecting module 1 and the cylinder, the other end of the cylinder being slidably connected to the second connecting module, the second connecting module being able to extend or retract into the cylinder, and the second sealing component being disposed between the cylinder and the second connecting module.

[0031] This application provides a bidirectional dynamic sealing compensator for shallow well formation testing. By configuring the cylinder and the second connecting module as a sliding connection structure, when the wellhead equipment experiences temperature changes, pressure fluctuations, or mechanical vibrations, the gap between the first and second connecting parts connected at both ends of the bidirectional dynamic sealing compensator changes. The second connecting module, connected to the second connecting part, can be compressed or stretched relative to the cylinder to achieve bidirectional compensation for the gap between the first and second connecting parts. This solves the technical problem of poor stability and low reliability in testing operations caused by the large clearance between the tubing hanger and the casing four-way valve in traditional technologies. In addition, the synergistic cooperation of the first and second sealing components forms a dual sealing guarantee mechanism, significantly improving the overall sealing performance and preventing safety hazards caused by compensator leakage.

[0032] In this embodiment, the first connector is a tubing string connected to the wellhead, and the second connector is a tubing hanger.

[0033] Specifically, for example, when the wellhead temperature changes, a decrease in temperature causes contraction, creating a gap between the tubing hanger and the casing four-way valve. The tubing hanger stretches the second connecting module, causing it to extend relative to the cylinder. Conversely, an increase in temperature causes thermal expansion, compressing the second connecting module and causing it to retract relative to the cylinder. This allows the wellhead bidirectional dynamic seal compensator to automatically adjust and compensate for changes in the distance between the tubing hanger and the casing four-way valve. Furthermore, the specific process of bidirectional compensation by the wellhead bidirectional dynamic seal compensator based on changes in the distance between the tubing hanger and the casing four-way valve due to pressure fluctuations or mechanical vibrations is the same as the thermal contraction caused by temperature changes, and will not be elaborated further here.

[0034] In this embodiment of the application, the male buckle is a 2-7 / 8EUE type male buckle, the female buckle is a 2-7 / 8EUE type female buckle, and the inside of the cylinder is polished using magnetorheological technology.

[0035] like Figure 1 As shown, in some embodiments, the first connecting module 1 is provided with a first annular sealing groove, and the first sealing assembly includes a first support ring 4 and a first sealing ring 5, which are sleeved in the first annular sealing groove.

[0036] By setting a first annular sealing groove in the first connecting module 1, the first support ring 4 and the first sealing ring 5 can be limited, thereby preventing the first support ring 4 and the first sealing ring 5 from shifting between the first connecting module 1 and the sealing module 2, which would lead to sealing failure and leakage.

[0037] like Figure 1 As shown, in some embodiments, the first connecting module 1 further includes a connecting part, which is inserted into the cylinder. The connecting part has a screw positioning groove 6, and the cylinder has a corresponding positioning hole. The screw passes through the positioning hole and is screwed into the screw positioning groove 6 so that the first connecting module 1 is fixedly connected to the cylinder.

[0038] The alignment design of the screw positioning slots 6 with the positioning holes allows for quick alignment of the first connecting module 1 and the cylinder during installation, significantly shortening assembly time and improving work efficiency. Furthermore, the rigid connection formed by tightening the screws greatly improves vibration resistance and prevents loosening, avoiding loosening during dynamic compensation and ensuring accuracy. In addition, the modular design facilitates disassembly, thereby greatly improving maintenance efficiency.

[0039] like Figure 1 As shown, in some embodiments, the first connection module 1 further includes a plug-in part, which has a plug-in groove, and a guide groove is provided on the side of the plug-in groove away from the cylinder.

[0040] The interference fit between the plug slot and the first connector creates a mechanical interlock, preventing the plug from accidentally dislodging during dynamic compensation, which could lead to unstable connection or detachment between the plug slot and the first connector, resulting in leakage. Furthermore, the guide groove design allows the plug and the first connector to self-align, eliminating the need for repeated manual adjustments and significantly improving installation efficiency.

[0041] In this embodiment, the cross-section of the guide groove is funnel-shaped.

[0042] like Figure 1 and Figure 2 As shown, in some embodiments, the second connecting module further includes a mandrel 3, which is inserted into the cylinder and slidably connected to the cylinder. An annular limiting protrusion is provided at one end of the mandrel 3 near the cylinder, and an annular limiting step is provided inside the cylinder. The annular limiting protrusion can engage with the annular limiting step.

[0043] Smooth axial movement is ensured through a precise sliding fit between the mandrel 3 and the cylinder. Simultaneously, the snap-fit ​​structure of the annular limiting protrusion and the annular limiting step effectively limits the maximum extension and retraction of the mandrel 3 and prevents accidental disengagement during dynamic compensation. Furthermore, the snap-fit ​​structure of the annular limiting protrusion and the annular limiting step enhances the overall vibration resistance of the compensator, preventing safety hazards such as seal failure and tubing disengagement. It also balances high-precision dynamic compensation with long-term reliability, significantly improving the overall stability of the compensator.

[0044] In this embodiment, the limiting protrusion is made of 42CrMo alloy steel.

[0045] like Figures 1-2 As shown, in some embodiments, the mandrel 3 is provided with a second annular sealing groove and a third annular sealing groove. The second sealing assembly includes a second support ring 4 and a second sealing ring 5, which are fitted inside the second annular sealing groove. The sealing module 2 also includes a third sealing assembly, which includes a third support ring 4 and a third sealing ring 5, which are fitted inside the third annular sealing groove.

[0046] By forming a double sealing barrier through the second and third sealing components, zero leakage can be achieved at a working pressure of 70MPa. Furthermore, the double sealing design ensures that the system can still maintain its sealing capability even if the primary seal fails, preventing leakage from occurring due to the failure of the primary seal. This avoids the possibility of sealing failure of the compensator under high pressure and high frequency conditions.

[0047] In this embodiment, both the second support ring 4 and the third support ring 4 are made of PEEK composite material, and the support ring 4 is provided with a 45° guide slope so that the compression of the sealing ring 5 is always kept within the optimal range of 20±2%.

[0048] In this embodiment, the second sealing ring 5 and the third sealing ring 5 are made of PTFE material.

[0049] In some embodiments, a pressure balancing hole is provided between the second sealing groove and the third sealing groove.

[0050] By setting a pressure balance hole, the pressure of the second and third sealing grooves can be automatically adjusted, effectively preventing deformation or damage to one of the sealing rings 5 ​​due to excessive pressure difference, thereby greatly extending the service life of the second and third sealing rings 5.

[0051] like Figures 1-2 As shown, in some embodiments, the outer cross-section of the mandrel 3 is square, and the inner side of the cylinder is set to be square to match the outer side of the mandrel.

[0052] By setting the outer cross section of the mandrel 3 to be square, the rotation of the mandrel 3 relative to the cylinder along the axial direction can be restricted. The mating structure between the mandrel 3 and the cylinder can control the circumferential rotation angle, thereby preventing wear of the sealing surface, the second sealing ring 5 and the third sealing ring 5 caused by the rotation of the mandrel 3 relative to the cylinder along the axial direction. This greatly extends the service life of the second sealing ring 5 and the third sealing ring 5, and avoids the deflection of the sealing surface that occurs during the dynamic compensation process, which would reduce the sealing effect and cause leakage, as well as cause uneven torque transmission, thereby reducing structural stability and making it impossible to achieve precise self-adjustment.

[0053] In this embodiment, the mandrel 3 is integrally forged from 42CrMo alloy steel.

[0054] like Figures 1-2 As shown, in some embodiments, the end of the mandrel 3 away from the cylinder is provided with a guide portion, and the cross-section of the guide portion is tapered.

[0055] By setting a tapered guide, rapid, accurate, and automatic centering installation can be achieved, which greatly improves installation efficiency and solves the problems of difficult installation of compensators under complex well conditions and early seal failure.

[0056] like Figures 1-2 As shown, in some embodiments, the relative sliding stroke between the mandrel 3 and the cylinder is greater than or equal to 500 mm.

[0057] By limiting the relative sliding stroke between the mandrel 3 and the cylinder, the device can achieve more precise self-adjustment. In addition, in other embodiments, the operator can change the relative sliding stroke between the mandrel 3 and the cylinder according to specific needs, which will not be elaborated here.

[0058] In some embodiments, the diameter of the cylinder is 50 mm.

[0059] By setting a cylinder with a diameter of 50mm, it can support the simultaneous operation of multiple devices such as hydraulic pipelines and fiber optic cables, thereby realizing the completion of composite functions such as testing and monitoring with "one pipe column".

[0060] Secondly, an embodiment of this application also provides a shallow well formation testing system, including the above-mentioned wellhead bidirectional dynamic seal compensator, as well as a wellhead device and a test string. The wellhead device includes a casing four-way connector and a tubing hanger. The test string is suspended in the wellbore through the tubing hanger. The first connecting module 1 is fixedly connected to the wellhead device, and the second connecting module is connected to the test string.

[0061] The shallow well formation testing system in this embodiment has a dynamic compensation capability of 500mm ultra-long stroke, which can sense and automatically adjust the displacement of the tubing in real time, thereby solving the problem of tubing stress caused by temperature changes. Furthermore, through a triple sealing structure and an intelligent monitoring system, it forms a closed-loop control of "monitoring-compensation-protection", achieving zero leakage under 70MPa high pressure. In addition, the 50mm inner diameter design supports the simultaneous operation of multiple devices such as hydraulic pipelines and fiber optic cables, realizing the completion of composite functions such as testing and monitoring with "one tubing".

[0062] In some embodiments, the shallow well formation testing system further includes a data acquisition unit and a hydraulic control system. The data acquisition unit can monitor the displacement and sealing pressure of the compensator in real time, and the hydraulic control system can automatically adjust the working state of the compensator according to the acquired data.

[0063] By setting up a data acquisition unit and a hydraulic control system, the working status and internal conditions of the compensator can be monitored in real time, allowing operators to have a clearer understanding of the compensator's real-time situation and make timely adjustments to ensure stable operation.

[0064] Although the present invention has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A bidirectional dynamic seal compensator for wellheads used in shallow well formation testing, characterized in that, include: A first connecting module, the first connecting module including a female buckle, the female buckle being used to connect with a first connecting member; The second connecting module includes a male buckle for connecting with the second connecting piece; A sealing module includes a cylinder, a first sealing component, and a second sealing component. One end of the cylinder is fixedly connected to the first connecting module. The first sealing component is disposed between the first connecting module and the cylinder. The other end of the cylinder is slidably connected to the second connecting module. The second connecting module can extend or retract into the cylinder. The second sealing component is disposed between the cylinder and the second connecting module.

2. The wellhead bidirectional dynamic sealing compensator according to claim 1, characterized in that, The first connecting module is provided with a first annular sealing groove, and the first sealing component includes a first support ring and a first sealing ring, which are fitted inside the first annular sealing groove.

3. The wellhead bidirectional dynamic sealing compensator according to claim 1, characterized in that, The first connecting module further includes a connecting part, which is inserted into the cylinder. The connecting part has a screw positioning groove, and the cylinder has a corresponding positioning hole. The screw passes through the positioning hole and is screwed into the screw positioning groove, so that the first connecting module is fixedly connected to the cylinder.

4. The wellhead bidirectional dynamic sealing compensator according to claim 1, characterized in that, The first connection module further includes a plug-in part, which has a plug-in groove and a guide groove on the side of the plug-in groove away from the cylinder.

5. The wellhead bidirectional dynamic sealing compensator according to claim 1, characterized in that, The second connection module further includes a mandrel, which is inserted into the cylinder and slidably connected to the cylinder. An annular limiting protrusion is provided at one end of the mandrel near the cylinder, and an annular limiting step is provided inside the cylinder. The annular limiting protrusion can engage with the annular limiting step.

6. The wellhead bidirectional dynamic sealing compensator according to claim 5, characterized in that, The mandrel is provided with a second annular sealing groove and a third annular sealing groove. The second sealing assembly includes a second support ring and a second sealing ring, which are fitted inside the second annular sealing groove. The sealing module also includes a third sealing assembly, which includes a third support ring and a third sealing ring, which are fitted inside the third annular sealing groove.

7. The wellhead bidirectional dynamic sealing compensator according to claim 5, characterized in that, The outer cross-section of the mandrel is square, and the inner side of the cylinder is set to be square to match the outer side of the mandrel.

8. The wellhead bidirectional dynamic seal compensator according to claim 5, characterized in that, The mandrel is provided with a guide portion at the end away from the cylinder, and the cross-section of the guide portion is conical.

9. The wellhead bidirectional dynamic sealing compensator according to claim 5, characterized in that, The relative sliding stroke between the mandrel and the cylinder is greater than or equal to 500 mm.

10. A shallow well formation testing system, characterized in that, The wellhead bidirectional dynamic seal compensator as described in any one of claims 1-9 is further comprising a wellhead device including a casing four-way connector and a tubing hanger; a test string suspended inside the wellbore via the tubing hanger; a first connecting module fixedly connected to the wellhead device; and a second connecting module connected to the test string.

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