Ultrahigh-pressure anti-seismic and anti-disengagement fracturing manifold

Abstract

The ultrahigh-pressure anti-seismic and anti-disengagement fracturing manifold comprises a manifold bottom pry, a high-pressure manifold assembly, a low-pressure manifold assembly and an anti-disengagement device, the high-pressure manifold assembly and the low-pressure manifold assembly are both installed on the manifold bottom pry, and the high-pressure manifold assembly is located above the low-pressure manifold assembly; the high-pressure manifold assembly comprises a flange straight pipe, a union flange, a plug valve and a movable elbow, the union flange and the flange straight pipe are connected through self-tightening conical threads, the union flange and the plug valve are connected through self-tightening conical threads, the anti-disengaging device comprises an anti-explosion hoop, a supporting steel pipe and an anti-disengaging ring, the anti-explosion hoop is fixedly connected outside the movable elbow, and the supporting steel pipe is fixedly connected outside the anti-disengaging ring. One end of the supporting steel pipe is fixedly connected with the anti-explosion hoop, the middle of the supporting steel pipe penetrates through the anti-disengaging ring, the bottom of the supporting steel pipe is fixedly connected with the manifold bottom pry, and the anti-disengaging ring is fixedly connected above the manifold bottom pry. The device can stably work under the severe working conditions of ultrahigh pressure and strong vibration, the reliability and safety of shale gas fracturing operation are effectively improved, and equipment faults and safety accident risks are reduced.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction equipment technology, and in particular to an ultra-high pressure anti-vibration and anti-detachment fracturing manifold. Background Technology

[0002] In the field of oil and gas extraction, especially shale gas development, as extraction operations extend into deeper formations, the pressure requirements for fracturing processes have continued to rise, increasing from the traditional 70MPa-100MPa to 140MPa and above. However, the API 6A standard manifolds widely used in the industry currently have a rated pressure of only 103.5MPa. This pressure level is no longer sufficient to meet the ultra-high pressure requirements of current deep shale gas fracturing operations, becoming one of the key equipment bottlenecks restricting the efficient development of shale gas.

[0003] Currently, the mainstream fracturing manifolds mostly adopt 42CrMo flange connection structures in structural design, and are equipped with conventional anti-loosening bolts and rubber shock-absorbing pads to cope with vibration and pressure shock in the working environment. However, in actual application scenarios, such as field operations in Sichuan shale gas fields, this type of traditional structure exposes many technical defects, which seriously affect the safety and stability of fracturing operations. Specifically, it is reflected in the following three aspects: (1) The problem of joint loosening under vibration environment is prominent. Under vibration load (such as encountering a magnitude 6 earthquake or high-frequency vibration of the operating equipment), the bolts of the traditional flange bolt connection are prone to loosening, which leads to high-pressure fluid leakage in the manifold. According to field statistics, the proportion of well site safety accidents caused by this type of problem is as high as 30%, which not only causes operation interruption, but also poses a hidden danger of causing fire, explosion and other major safety risks; (2) High-pressure pulsation impact is prone to cause manifold fatigue failure. During the fracturing operation, the manifold The fluid pressure inside the manifold is often in a pulsating state of 70MPa-150MPa. Under the action of such high pressure pulsating cyclic load, the welded joints of the traditional manifold are prone to fatigue cracks and the cracks continue to expand, eventually leading to early fracture of the joint, which greatly shortens the service life of the manifold and increases the equipment maintenance cost and the frequency of operation downtime. (3) The reliability of the traditional anti-detachment structure is insufficient. Most existing manifolds use double nut locking or union cap as anti-detachment measures. However, under ultra-high pressure conditions, double nuts are prone to weakening of locking force and union caps are prone to sealing failure. Moreover, neither of these structures can monitor the loosening state of the connection in real time, making it difficult to warn of potential failure risks in advance and unable to provide stable anti-detachment protection for ultra-high pressure fracturing operations. Summary of the Invention

[0004] The purpose of this invention is to provide an ultra-high pressure anti-seismic and anti-detachment fracturing manifold to solve the above-mentioned problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This invention discloses an ultra-high pressure seismic-resistant and anti-detachment fracturing manifold, comprising a manifold base skid, a high-pressure manifold assembly, a low-pressure manifold assembly, and an anti-detachment device. Both the high-pressure and low-pressure manifold assemblies are mounted on the manifold base skid, with the high-pressure manifold assembly positioned above the low-pressure manifold assembly. The high-pressure manifold assembly includes a flanged straight pipe, a union flange, a plug valve, and a movable elbow. The union flange and the flanged straight pipe, as well as the union flange and the plug valve, are connected via self-tightening tapered threads. A pre-tightening ring is fitted at the connection point of the self-tightening tapered thread to form an anti-detachment structure. The anti-detachment device includes an explosion-proof clamp, a supporting steel pipe, and an anti-detachment ring. The explosion-proof clamp is fixedly connected to the outside of the movable elbow. One end of the supporting steel pipe is fixedly connected to the explosion-proof clamp, the middle portion passes through the anti-detachment ring, and the bottom is fixedly connected to the manifold base skid. The anti-detachment ring is fixedly connected above the manifold base skid.

[0007] Furthermore, an integrated support frame is fixedly connected to the manifold bottom skid, and the high-pressure manifold is assembled and installed on the integrated support frame.

[0008] Furthermore, a fixing plate is fixedly connected to the integrated support frame, and the anti-detachment ring is fixedly connected to the fixing plate by a first fixing bolt.

[0009] Furthermore, a base plate is fixedly connected to the manifold bottom skid, and the bottom of the supporting steel pipe is fixedly connected to the base plate by a second fixing bolt.

[0010] Furthermore, the flange straight pipe adopts an integral forging structure, and the inner cavity of the flange straight pipe is overlaid with a hard alloy layer with a thickness of not less than 3mm.

[0011] Furthermore, the low-pressure manifold assembly is mounted on the manifold base skid via a support clamp.

[0012] Furthermore, the contact surface of the explosion-proof clamp is provided with a sharkskin pattern.

[0013] Furthermore, the depth of the texture is 20μm-50μm, and the texture spacing is 100μm-200μm.

[0014] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0015] The ultra-high pressure anti-seismic fracturing manifold of this invention greatly improves the reliability of the connection by adopting a self-tightening tapered thread and a pre-tightening ring anti-detachment structure, ensuring that it can withstand high pressures under 10°C conditions. 7After one pressure cycle, the bolt preload loss is less than 3%, which is better than the API 6A standard. At the same time, the flange straight pipe adopts an integral forging + local reinforcement structure, and the stress distribution is optimized by finite element method, which increases the fatigue life by 5 times. ANSYS simulation shows that the stress concentration factor is less than 1.1. In addition, the movable elbow is directly locked by the explosion-proof clamp. Even if the connection of the tightening cap fails, the movable elbow can be fixed next to the plug valve, which effectively reduces the danger. In addition, the explosion-proof clamp adopts a sharkskin texture design with a texture depth of 20-50μm and a spacing of 100-200μm, which further enhances the relevant performance. This invention is particularly suitable for shale gas fracturing operations. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the main structure of the ultra-high pressure anti-seismic and anti-detachment fracturing manifold of the present invention;

[0018] Figure 2 This is a top view of the ultra-high pressure anti-seismic and anti-detachment fracturing manifold of the present invention;

[0019] Figure 3 This is a side view of the ultra-high pressure anti-seismic and anti-detachment fracturing manifold of the present invention;

[0020] Figure 4 for Figure 3 A magnified schematic diagram of the partial structure at point A in the middle;

[0021] Figure 5 This is a schematic diagram of the integrated support frame in the ultra-high pressure anti-seismic and anti-detachment fracturing manifold of the present invention.

[0022] Explanation of reference numerals in the attached drawings: 1. Manifold skid; 11. Base plate; 12. Second fixing bolt; 2. High-pressure manifold assembly; 3. Low-pressure manifold assembly; 4. Integrated support frame; 41. Fixing plate; 42. First fixing bolt; 5. Movable elbow; 6. Anti-detachment device; 61. Explosion-proof clamp; 62. Supporting steel pipe; 63. Anti-detachment ring; 7. Union flange; 8. Plug valve. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] In the description of this invention, it should be understood that the terms "length," "width," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention 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 the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral 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. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] The technical solutions provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0027] like Figures 1 to 5 As shown, the ultra-high pressure anti-seismic and anti-loosening fracturing manifold of this embodiment includes a manifold base skid 1, a high-pressure manifold assembly 2, a low-pressure manifold assembly 3, and an anti-loosening device 6. Both the high-pressure manifold assembly 2 and the low-pressure manifold assembly 3 are installed on the manifold base skid 1, and the high-pressure manifold assembly 2 is located above the low-pressure manifold assembly 3, forming a layered layout of high pressure on the upper layer and low pressure on the lower layer. This not only meets the independent transmission requirements of high and low pressure fluids in fracturing operations, but also saves the installation space of the manifold at the well site. The high-pressure manifold assembly 2 includes a flange straight pipe, a union flange 7, a plug valve 8, and a movable elbow 5. The union flange 7 and the flange straight pipe, and the union flange 7 and the plug valve 8 are connected by self-tightening tapered threads. A pre-tightening ring is fitted at the connection part of the self-tightening tapered thread to form an anti-loosening structure. The double anti-loosening structure of self-tightening tapered thread and pre-tightening ring locking enhances the vibration resistance of the connection part.

[0028] Specifically, such as Figure 4 As shown, the anti-detachment device 6 includes an explosion-proof clamp 61, a supporting steel pipe 62, and an anti-detachment ring 63. The explosion-proof clamp 61 is fixedly connected to the outside of the movable elbow 5. One end of the supporting steel pipe 62 is fixedly connected to the explosion-proof clamp 61, the middle part slides through the anti-detachment ring 63, and the bottom is fixedly connected to the manifold bottom skid 1. The anti-detachment ring 63 is fixedly connected above the manifold bottom skid 1, thereby achieving double fixation of the movable elbow 5.

[0029] like Figure 1 , Figure 2 As shown, the high-pressure pipe assembly 2 adopts a modular design, specifically including components such as flanged straight pipes, four-way, five-way, union flange 7, safety valve and plug valve 8. An integrated support frame 4 is fixedly connected to the bottom skid 1 of the manifold. The high-pressure pipe assembly 2 is installed on the integrated support frame 4. Furthermore, a fixing plate 41 is fixedly connected to the bottom of the crossbeam of the integrated support frame 4. The anti-detachment ring 63 is fixedly connected to the fixing plate 41 through the first fixing bolt 42, so that the installation position of the anti-detachment ring 63 is precisely matched with the height of the movable elbow 5, ensuring the anti-detachment constraint effect of the supporting steel pipe 62 on the movable elbow 5.

[0030] In this embodiment, the low-pressure manifold assembly 3 includes a stainless steel main pipeline, a butterfly valve, a low-pressure stainless steel pipeline, an acid-resistant butterfly valve, and unions, etc. After the components are connected, a complete low-pressure fluid passage is formed, which is adapted to the transmission requirements of low-pressure flowback fluid and auxiliary fluid in fracturing operations. At this time, the low-pressure manifold assembly 3 is installed on the manifold bottom skid 1 by a support clamp. The bottom of the support clamp is welded and fixed to the manifold bottom skid 1, and the top is clamped with bolts to secure the low-pressure pipeline. This avoids corrosion problems caused by direct contact between the low-pressure pipeline and the manifold bottom skid 1, and also buffers the impact of operational vibration on the low-pressure pipeline.

[0031] like Figure 3 , Figure 5 As shown, a base plate 11 is fixedly connected to the manifold bottom skid 1, and the bottom of the support steel pipe 62 is fixedly connected to the base plate 11 by the second fixing bolt 12.

[0032] Preferably, the flange straight pipe adopts an integral forging structure. The integral forging process can ensure the uniform internal structure of the flange straight pipe, eliminate internal defects, and improve its strength and toughness. In addition, the inner cavity of the flange straight pipe is reinforced with a hard alloy layer with a thickness of not less than 3mm by welding a pure alloy layer to enhance the overall strength of the flange straight pipe. This can strengthen the parts of the flange straight pipe that are subjected to high stress in the manifold, further improving the load-bearing capacity of the flange straight pipe and enabling it to better adapt to the ultra-high pressure working environment.

[0033] Furthermore, a sharkskin pattern is provided on the inner wall surface where the explosion-proof clamp 61 contacts the movable elbow 5. The depth of the pattern is 20μm-50μm and the spacing between the patterns is 100μm-200μm, which can increase the friction of the contact surface of the explosion-proof clamp 61. When the explosion-proof clamp 61 locks the movable elbow 5, it can more effectively prevent the movable elbow 5 from sliding or detaching. At the same time, the pattern can also disperse stress to a certain extent, reduce stress concentration damage to the explosion-proof clamp 61 and the movable elbow 5, and extend their service life.

[0034] In this embodiment of the ultra-high pressure anti-vibration and anti-detachment fracturing manifold, the various components of the manifold are first assembled according to the design requirements to ensure that all connections are tight and reliable. During operation, the high-pressure fracturing fluid enters the manifold through the high-pressure manifold 2, and the low-pressure fluid returns or is transported through the low-pressure manifold 3. When encountering vibration loads, the self-tightening tapered thread and pre-tightening ring structure can resist bolt loosening. If the tightening cap connection fails unexpectedly, the anti-detachment device 6 can fix the movable elbow 5 to the side of the stop valve 8 to prevent the movable elbow 5 from falling off and causing high-pressure fluid leakage.

[0035] This embodiment of the ultra-high pressure seismic-resistant and anti-detachment fracturing manifold ensures 10 by setting a self-tightening tapered thread and a pre-tightening ring anti-detachment structure. 7 After a single pressure cycle, the bolt preload loss is less than 3%, exceeding the performance of the API 6A standard. This effectively solves the problem of loosening of traditional flange bolt connections under vibration scenarios such as a magnitude 6 earthquake. By adopting an integral forging and locally reinforced flange straight pipe structure and optimizing stress distribution, the fatigue life of the manifold is increased by 5 times, making it suitable for high-pressure pulsating conditions of 70MPa-150MPa and avoiding early fracture of traditional welded joints. By setting explosion-proof clamps with sharkskin texture and anti-loosening devices, even if the manifold cap fails, the movable elbow can be fixed, minimizing safety risks and ultimately achieving safe and stable operation of shale gas fracturing ultra-high pressure operations.

[0036] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A high-pressure, earthquake-resistant, anti-detachment, fracturing manifold, characterized in that, The system includes a manifold skid, a high-pressure manifold assembly, a low-pressure manifold assembly, and an anti-detachment device. Both the high-pressure and low-pressure manifold assemblies are mounted on the manifold skid, with the high-pressure manifold assembly positioned above the low-pressure manifold assembly. The high-pressure manifold assembly includes a flanged straight pipe, a union flange, a plug valve, and a movable elbow. The union flange and the flanged straight pipe, as well as the union flange and the plug valve, are connected via self-tightening tapered threads. A pre-tightening ring is fitted onto the connection portion of the self-tightening tapered thread to form an anti-detachment structure. The anti-detachment device includes an explosion-proof clamp, a supporting steel pipe, and an anti-detachment ring. The explosion-proof clamp is fixedly connected to the outside of the movable elbow. One end of the supporting steel pipe is fixedly connected to the explosion-proof clamp, the middle portion passes through the anti-detachment ring, and the bottom is fixedly connected to the manifold skid. The anti-detachment ring is fixedly connected above the manifold skid.

2. The ultra-high pressure seismic-resistant and anti-detachment fracturing manifold according to claim 1, characterized in that, An integrated support frame is fixedly connected to the manifold bottom skid, and the high-pressure manifold is assembled and installed on the integrated support frame.

3. The ultra-high pressure seismic-resistant and anti-detachment fracturing manifold according to claim 2, characterized in that, A fixing plate is fixedly connected to the integrated support frame, and the anti-detachment ring is fixedly connected to the fixing plate by the first fixing bolt.

4. The ultra-high pressure anti-seismic and anti-detachment fracturing manifold according to claim 1, characterized in that, A base plate is fixedly connected to the manifold bottom skid, and the bottom of the supporting steel pipe is fixedly connected to the base plate by a second fixing bolt.

5. The ultra-high pressure anti-seismic and anti-detachment fracturing manifold according to claim 1, characterized in that, The flange straight pipe adopts an integral forging structure, and the inner cavity of the flange straight pipe is overlaid with a hard alloy layer with a thickness of not less than 3mm.

6. The ultra-high pressure seismic-resistant and anti-detachment fracturing manifold according to claim 1, characterized in that, The low-pressure manifold is assembled and mounted on the manifold base skid via a support clamp.

7. A high-pressure anti-seismic and anti-detachment fracturing manifold according to any one of claims 1-6, characterized in that, The contact surface of the explosion-proof clamp is decorated with a sharkskin pattern.

8. The ultra-high pressure anti-seismic and anti-detachment fracturing manifold according to claim 7, characterized in that, The depth of the texture is 20μm-50μm, and the spacing between the textures is 100μm-200μm.

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