A blowout venting and desanding device after oil well fracturing

Abstract

This invention discloses a post-fracturing air venting and desanding device for oil wells, comprising a vertical air manifold unit, a multi-stage desanding pipeline unit, and a PLC logic control terminal. The vertical air manifold unit includes an inlet pipeline and a vertical air manifold. A degassing pipeline with a first electric ball valve is located at the top of the vertical air manifold. The multi-stage desanding pipeline unit includes several parallel desanding components, each including a pair of sand settling risers. Each sand settling riser has several second electric ball valves on its top. A venting riser with a venting horizontal pipe is located at the top of each venting riser. An obliquely arranged venting pipe is located between the upper parts of the pair of sand settling risers. A sand discharge riser with a horizontally arranged sand discharge pipe is located at the lower end of each sand settling riser. This post-fracturing air venting and desanding device solves the problems of poor desanding effect and high maintenance workload of current fracturing flowback fluid desanding devices, effectively reducing maintenance workload and ensuring timely air venting.

Description

Technical Field

[0001] This invention relates to an oilfield device, and more specifically, to a well fracturing, blowout, desanding, and venting device. Background Technology

[0002] Oil well fracturing is an effective means to improve the productivity of low-permeability reservoirs. To prevent the fracturing fractures from closing on their own, proppant is introduced into the fractures through fluid during the fracturing process to keep them open. However, during the flowback process after fracturing, the flowback fluid usually carries some proppant and solid particles such as formation mud and sand into the process flow. If not effectively treated, these solid particles will settle and accumulate in the pipeline, causing a sudden drop in pipeline diameter and flow rate, an abnormal increase in system pressure, and even complete pipeline blockage. Some oil wells also carry a large amount of gas during the flowback, which directly enters the gathering and transportation process, adding to the difficulty of subsequent degassing treatment.

[0003] Currently, the main method for dealing with solid particles in the Subei Oilfield is to reduce the amount of solid particles carried by controlling the flow rate of the flowback fluid by selecting an appropriate diameter nozzle. Additionally, a cuttings catcher is installed at the wellhead to further reduce the solid particle content through filtration. However, in practice, the flowback fluid still carries some solid particles. The cuttings catcher often becomes narrower or even completely blocked due to the accumulation of solid particles. Disassembling and cleaning the cuttings catcher during field management requires pausing the flowback process, which is cumbersome, slows down the work, and is inefficient. Furthermore, there are no pre-degassing measures for wells with high gas content in the flowback fluid. Summary of the Invention

[0004] Therefore, it is necessary to provide a gas venting and sand removal device after oil well fracturing to address the aforementioned technical problems.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A post-fracturing gas venting and desanding device for oil wells is characterized in that it comprises a vertical air manifold unit, a multi-stage desanding pipeline unit, and a PLC logic control terminal. The vertical air manifold unit includes a horizontally arranged liquid inlet pipeline and a vertically arranged air manifold. A degassing pipeline is located at the top of the vertical air manifold, and a first electric ball valve is installed on the degassing pipeline. An emergency pressure relief pipeline is also located at the top of the vertical air manifold. The multi-stage sand removal pipeline unit includes several parallel sand removal components. Each sand removal component includes a pair of longitudinally arranged sand settling risers. Each sand settling riser is equipped with several second electric ball valves. Each sand settling riser has a discharge riser at its top and a horizontally arranged discharge pipe at its top. An obliquely arranged discharge pipe is provided between the upper parts of the pair of longitudinally arranged sand settling risers. Each sand settling riser has a sand discharge riser at its lower part and a horizontally arranged sand discharge pipe at its lower end.

[0006] In a preferred embodiment of the present invention, a safety valve is provided at the top of the vertical air tank.

[0007] In a preferred embodiment of the present invention, a radar level gauge is provided on the side wall of the vertical air tank, and the radar level gauge, the first electric ball valve, and the second electric ball valve are all connected to the PLC logic control terminal through signal transmission lines.

[0008] In a preferred embodiment of the present invention, the inclination angle of the discharge pipe is between 30° and 45°.

[0009] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a post-fracturing blowout venting and desanding device for oil wells. This device aims to divert and reduce the flow velocity of the blowout return fluid to better achieve sand settling. In addition, the parallel connection of multiple sets effectively prevents abnormal situations such as sand blockage during single-set operation, ensuring safety. This post-fracturing blowout venting and desanding device solves the problems of poor desanding effect and large cleaning and maintenance workload of current fracturing return fluid desanding devices, effectively reducing maintenance workload and ensuring timely blowout. Attached Figure Description

[0010] To more clearly illustrate the solutions in this invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the structure of the oil well fracturing blowout venting and sand removal device of the present invention; Figure 2 for Figure 1 A schematic diagram of the vertical air tank unit of the oil well fracturing blowout and desanding device; Figure 3 for Figure 1 A schematic diagram of the desanding component of the multi-stage desanding pipeline unit in the oil well fracturing blowout and desanding device; The markings in the diagram are explained as follows: 1. Vertical air tank; 10. Safety valve at the top; 11. Horizontal discharge pipe; 12. Vertical discharge pipe at the top; 13. Inclined discharge pipe; 14. Sand settling pipe; 15. Sand discharge pipe; 16. Horizontal sand discharge pipe; 4. Degassing pipeline; 5. First electric ball valve; 5S. Second electric ball valve; 6. Signal transmission line; 7. Liquid inlet pipeline; 8. Radar level gauge; 9. Emergency pressure relief pipeline; S1. Vertical air tank unit; S2. Multi-stage sand removal pipeline unit; S20. Sand removal assembly; S3. PLC logic control terminal. Detailed Implementation

[0012] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0013] The well fracturing and desanding device includes a vertical air tank unit S1, a multi-stage desanding pipeline unit S2, and a PLC logic control terminal S3.

[0014] The vertical air bag unit S1 includes a horizontally arranged liquid inlet pipeline 7 and a vertically arranged vertical air bag 1. The top of the vertical air bag 1 is provided with a degassing pipeline 4, and a first electric ball valve 5 is provided on the degassing pipeline 4. The top of the vertical air bag 1 is provided with an emergency pressure relief pipeline 9.

[0015] It should be noted that a safety valve 10 is provided at the top of the vertical air tank 1. A radar level gauge 8 is provided on the side wall of the vertical air tank 1. The radar level gauge 8 and the first electric ball valve 5 are both connected to the PLC logic control terminal S3 through the signal transmission line 6.

[0016] The multi-stage sand removal pipeline unit S2 includes several parallel sand removal components S20. Each sand removal component S20 includes a pair of longitudinally arranged sand settling risers 14. Each sand settling riser 14 is equipped with several second electric ball valves 5S. Each sand settling riser 14 is equipped with a discharge riser 12 at its top. Each discharge riser 12 is equipped with a horizontally arranged discharge crosspipe 11 at its top. The upper parts of the pair of longitudinally arranged sand settling risers 14 are equipped with a diagonally arranged discharge oblique pipe 13. Each sand settling riser 14 is equipped with a sand discharge riser 15 at its lower part. The lower end of each sand discharge riser 15 is equipped with a horizontally arranged sand discharge crosspipe 16.

[0017] In addition, the second electric ball valve 5S is also connected to the PLC logic control terminal S3 via signal transmission line 6.

[0018] The following describes the working method of the blowout, venting, and sand removal device after fracturing the oil well.

[0019] After well fracturing, during the blowout, some of the associated gas in the flowback fluid enters the vertical gas manifold unit S1 from the multi-stage desanding pipeline unit S2 for pre-degassing, reducing the flow rate of the flowback fluid and facilitating the settling of solid particles in the subsequent multi-stage sand discharge pipeline.

[0020] The radar level gauge 8 transmits the liquid level signal in the vertical air tank 1 to the PLC logic control terminal S3 in real time. The PLC logic control terminal S3 has a preset safe liquid level range value. When the liquid level in the vertical air tank 1 is higher than the preset value, the electric valve at the outlet of the degassing air path closes slightly or even closes completely; when the liquid level in the vertical air tank 1 is lower than the preset value, the PLC logic control terminal S3 automatically controls the electric valve at the outlet of the degassing air path to open wider to accelerate the venting. When the pressure in the vertical air tank 1 reaches the pressure limit of the safety valve 10, the safety valve 10 opens to drain the liquid and relieve pressure, thus providing protection.

[0021] The pre-degassed return liquid enters the multi-stage desanding pipeline unit S2. This multi-stage desanding pipeline unit S2 is divided into a sand settling mode and a sand discharge mode.

[0022] Taking a single sand removal pipeline combination as an example (e.g.) Figure 3 As shown, the electric ball valves 5S on the left are numbered 1#, 2#, and 3# from top to bottom, and the electric ball valves 5S on the right are numbered 4#, 5#, and 6# from top to bottom.

[0023] In sand settling mode, electric ball valves #1, #2, #4, and #5 are open, while electric ball valves #3 and #6 are closed. As the return fluid flows through the discharge riser 12 and the discharge inclined pipe 13, the solid particles it carries fall into the sand settling riser 14 due to gravity. To switch to sand discharge mode without interrupting discharge, electric ball valves #2 and #5 can be remotely closed via the PLC logic control terminal S3, followed by opening electric ball valves #3 and #6. Solid particles in the sand settling riser 14 are then discharged into the sand discharge horizontal pipe 16. Alternatively, electric ball valves #2 and #5 can be opened appropriately for flushing to complete sand discharge. After sand discharge, electric ball valves #3 and #6 are closed, and then electric ball valves #2 and #5 are fully opened to resume discharge of this group of sand removal pipelines. The sand discharge cycle should be determined based on the actual sand discharge volume in field applications.

[0024] It should be noted that the function of electric ball valves #1 and #4 is to close the circuit when a certain discharge pipeline is blocked by sand and cannot be automatically discharged, so as to facilitate manual sand removal.

[0025] This well fracturing venting and desanding device aims to divert and reduce the flow rate of the venting and flowback fluid to better achieve sand settling. In addition, the parallel connection of multiple sets effectively prevents abnormal situations such as sand blockage during single-set operation, ensuring safety. This well fracturing venting and desanding device solves the problems of poor sand removal effect and large cleaning and maintenance workload of current fracturing flowback fluid desanding devices, effectively reducing maintenance workload and ensuring timely venting.

[0026] Obviously, the embodiments described above are only some embodiments of this application, and not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application.

Claims

1. A device for venting, desanding, and air removal after fracturing an oil well, characterized in that, The oil well fracturing and subsequent blowout ventilation and desanding device includes a vertical air manifold unit (S1), a multi-stage desanding pipeline unit (S2), and a PLC logic control terminal (S3). The vertical air bag unit (S1) includes a horizontally arranged liquid inlet pipeline (7) and a vertically arranged air bag (1). The top of the vertical air bag (1) is provided with a degassing pipeline (4), and the degassing pipeline (4) is provided with a first electric ball valve (5). The top of the vertical air bag (1) is provided with an emergency pressure relief pipeline (9). The multi-stage sand removal pipeline unit (S2) includes several parallel sand removal components (S20). Each sand removal component (S20) includes a pair of longitudinally arranged sand settling risers (14). Each sand settling riser (14) is equipped with several second electric ball valves (5S). Each sand settling riser (14) is equipped with a discharge riser (12) at the top. Each discharge riser (12) is equipped with a horizontally arranged discharge horizontal pipe (11) at the top. An obliquely arranged discharge inclined pipe (13) is provided between the upper parts of the pair of longitudinally arranged sand settling risers (14). Each sand settling riser (14) is equipped with a sand discharge riser (15) at the lower part. The lower end of each sand discharge riser (15) is equipped with a horizontally arranged sand discharge horizontal pipe (16).

2. The oil well fracturing post-blowout venting and sand removal device according to claim 1, characterized in that, The vertical air tank (1) is equipped with a safety valve (10) at the top.

3. The oil well fracturing venting and desanding device according to claim 1, characterized in that, The vertical air tank (1) is equipped with a radar level gauge (8) on its side wall. The radar level gauge (8), the first electric ball valve (5), and the second electric ball valve (5S) are all connected to the PLC logic control terminal (S3) through a signal transmission line (6).

4. The oil well fracturing venting and desanding device according to claim 1, characterized in that, The inclination angle of the spray pipe (13) is between 30° and 45°.

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