Device for collecting gas in brine sample

Abstract

The utility model discloses a device for collecting gas in a brine sample, which comprises a cylinder body, a hydrophobic filtering device is fixed in the cylinder body, the cylinder body is divided into a first cavity and a second cavity through the hydrophobic filtering device, a gas separation component is arranged in the first cavity along the length direction, and a gas outlet is formed in the second cavity. Sealing devices are arranged at openings in the two sides of the barrel body, and each sealing device comprises a puncture-resistant sealing plug fixedly connected with the barrel body. Compared with the prior art, the first cavity and the second cavity are formed in the barrel, brine is conveyed into the first cavity through the puncture needle, then gas and liquid are separated through the hydrophobic filtering device, so that gas enters the second cavity, a sampling needle of a gas chromatograph is inserted into the second cavity at the moment, and the content of methane is detected; in the brine sampling process, the device is always in a sealed state, and the problem of gas dissipation is avoided, so that the methane detection precision is improved, and reliable reference information is provided for subsequent operation.

Description

Technical Field

[0001] This utility model relates to the field of natural gas extraction and brine treatment technology, and in particular to a gas collection device for brine samples. Background Technology

[0002] Salt cavern gas storage facilities use interconnected well technology as the core construction method. The production process includes complex steps such as gas injection and brine removal, gas storage expansion, and injection-production operation. Specifically, the gas injection and brine removal stage requires high-pressure gas injection to replace and remove the brine in the salt cavern, forming an effective gas storage space; the gas storage expansion stage increases the cavity volume through multiple rounds of "one injection and one removal" or "two injections and one removal" modes; and the injection-production operation stage requires dynamic balancing of gas injection pressure and brine removal efficiency.

[0003] However, during the entire life cycle operation of the gas storage facility, multiple risk factors lead to significant methane leakage risks: ① At the process level, insufficient precision in gas-liquid interface control can easily cause natural gas entrainment. Literature shows that when the gas-liquid interface is 2m below the lower end of the brine discharge pipe, an emergency shutdown is required; ② At the geological level, salt rock creep and interlayer dissolution may cause cavity deformation, leading to casing head seal failure; ③ At the engineering level, leakage of downhole tools and deterioration of cement sheath integrity can form leakage channels. Actual measurement data shows that the micro-leakage rate of the annular pressurized wellbore can reach 1mL / min.

[0004] Methane is the main leaking gas, with an explosion limit of 5%-15%. To ensure safe production, brine samples are taken during the brine discharge process, followed by gas-liquid separation. The gas is then tested for the presence of methane. However, the traditional sampling method involves loading the brine sample into a container and moving the probe of the methane detector above the container opening. When methane escapes from the brine, it can be detected. However, this method suffers from the problem of methane gas escaping and cannot accurately detect the methane content, thus failing to provide a reliable reference for subsequent operations. Utility Model Content

[0005] The main objective of this invention is to provide a gas collection device for brine samples. The device comprises a first chamber and a second chamber. Brine is introduced into the first chamber using a puncture needle, and then separated into gas and liquid by a hydrophobic filter, allowing the gas to enter the second chamber. At this point, the sampling needle of a gas chromatograph is inserted into the second chamber to detect the methane content. This device remains sealed throughout the brine sampling process to prevent gas escape, thereby improving the accuracy of methane detection and providing reliable reference information for subsequent operations.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A gas collection device for brine samples includes a cylindrical body, a hydrophobic filter device fixed inside the cylindrical body, a first chamber and a second chamber separated inside the cylindrical body by the hydrophobic filter device, a gas separation component arranged along the length direction in the first chamber, and sealing devices provided at the openings on both sides of the cylindrical body. The sealing devices include puncture-resistant sealing plugs fixedly connected to the cylindrical body and puncture needles for puncturing the puncture-resistant sealing plugs.

[0008] Furthermore, the gas separation assembly includes a spiral guide plate, the outer edge of which is fixedly connected to the inner wall of the first cavity.

[0009] Furthermore, the gas separation assembly also includes a rod that passes through the center of the spiral guide plate and is fixedly connected to the spiral guide plate.

[0010] Furthermore, the sealing device also includes a threaded cap, which is threadedly connected to the end of the cylinder, and the puncture-resistant sealing plug is located inside the threaded cap.

[0011] Furthermore, a puncture hole is provided on one side of the puncture-resistant sealing plug.

[0012] Furthermore, a feeding tube is fixedly connected to one end of the puncture needle, and a threaded tube is fixed to one end of the feeding tube.

[0013] Furthermore, the diameter of the puncture needle is less than 3 millimeters.

[0014] Furthermore, the hydrophobic filtration device is a PTFE microporous membrane with a pore size of less than 0.2 micrometers.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The device comprises a first cavity and a second cavity within its cylindrical body. Brine is introduced into the first cavity using a puncture needle, and then separated into gas and liquid phases by a hydrophobic filter, allowing the gas to enter the second cavity. The sampling needle of a gas chromatograph is then inserted into the second cavity to detect the methane content. Throughout the brine sampling process, the device remains sealed to prevent gas escape, thereby improving the accuracy of methane detection and providing reliable reference information for subsequent operations.

[0017] The outer edge of the spiral guide plate of this invention is fixedly connected to the inner wall of the first cavity, thereby forming a spiral flow channel in the first cavity. When the brine flows in the spiral flow channel, the movement path increases, thereby increasing the speed at which gas is separated from the brine.

[0018] The puncture-resistant sealing plug of this invention is located inside the threaded cap, thereby enabling the threaded cap to protect the puncture-resistant sealing plug. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a gas collection device for brine samples according to the present invention.

[0020] Figure 2 This is a schematic diagram of the sealing device structure of a gas collection device in brine samples according to the present invention.

[0021] In the diagram: 1. Cylinder; 101. First cavity; 102. Second cavity; 2. Hydrophobic filter; 3. Sealing device; 301. Threaded cap; 302. Puncture-resistant sealing plug; 3021. Puncture hole; 4. Feed pipe; 401. Threaded pipe; 5. Puncture needle; 6. Gas separation assembly; 601. Spiral guide plate; 602. Rod. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0023] like Figure 1-2 As shown, a gas collection device for brine samples includes a cylinder 1, a hydrophobic filter 2 fixed inside the cylinder 1, and a first chamber 101 and a second chamber 102 separated inside the cylinder 1 by the hydrophobic filter 2. A gas separation component 6 is arranged along the length direction inside the first chamber 101. Sealing devices 3 are provided at the openings on both sides of the cylinder 1. The sealing device 3 includes a puncture-resistant sealing plug 302 fixedly connected to the cylinder 1, and also includes a puncture needle 5 for puncturing the puncture-resistant sealing plug 302.

[0024] In this embodiment, such as Figure 1 As shown, a vacuum device, such as a vacuum syringe, is used to create a negative pressure in the first cavity 101 and the second cavity 102. One end of the puncture needle 5 is fixedly connected to a feed tube 4, and the other end of the feed tube 4 is fixed to a threaded tube 401, which is connected to a brine sampling pipe. Therefore, when brine sampling is required, the puncture-resistant sealing plug 302 (which seals the first cavity 101) can be aligned with the puncture needle 5, and the cylinder 1 can be moved, causing the puncture needle to penetrate into the first cavity 101. Then, when the sampling pipeline valve is opened, the brine in the pipeline will enter the first chamber 101 under negative pressure. Subsequently, this part of the brine will flow along the gas separation component 6, so that the gas in the brine will drift through the hydrophobic filter device 2 and enter the second chamber 102 to achieve gas-liquid separation. Then, the personnel will insert the gas chromatograph sampling needle into the second chamber 102 through another puncture-resistant sealing plug 302 (this puncture-resistant sealing plug 302 is used to seal the second chamber 102) to detect the methane content.

[0025] The puncture-resistant sealing plug 302 is composed of a double-layer composite membrane and an elastic support structure, with the specific layers as follows:

[0026] Outer layer (puncture layer): High-elasticity medical silicone membrane (thickness 0.5~1mm), characteristics: soft and easy to puncture, and the needle hole can be quickly closed by elastic deformation after being pulled out.

[0027] Intermediate layer (barrier layer): PTFE microporous membrane (thickness 0.1~0.2μm, pore size <0.5μm), characteristics: hydrophobic and corrosion resistant, the microporous structure closes under pressure after puncture, blocking gas / liquid permeation.

[0028] Inner layer (support layer): Silicone reinforced mesh (embedded with stainless steel spring coils), features: provides structural support and ensures the overall repositioning of the composite membrane after puncture.

[0029] The puncture-resistant sealing plug 302 is existing technology and can still achieve a sealing effect after multiple punctures, so we will not go into details here.

[0030] After the puncture needle 5 is fixed to the sampling tube, it should be covered with a protective sleeve when not in use to prevent injury to pedestrians.

[0031] Among them, such as Figure 1 As shown, the gas separation assembly 6 includes a spiral guide plate 601. The outer edge of the spiral guide plate 601 is fixedly connected to the inner wall of the first cavity 101, thereby forming a spiral flow channel in the first cavity 101. When the brine flows in the spiral flow channel, the movement path increases, thereby increasing the speed at which gas is separated from the brine.

[0032] The gas separation assembly 6 also includes a rod 602, which passes through the center of the spiral guide plate 601 and is fixedly connected to the spiral guide plate 601, thereby increasing the overall strength of the spiral guide plate 601.

[0033] Among them, such as Figure 1 and Figure 2 As shown, the sealing device 3 also includes a threaded cap 301. The outer periphery of the end of the cylinder 1 is provided with a matching thread. The threaded cap 301 is threadedly connected to the end of the cylinder 1. The puncture-resistant sealing plug 302 is located inside the threaded cap 301, so that the threaded cap 301 can protect the puncture-resistant sealing plug 302.

[0034] like Figure 1 and Figure 2 As shown, a puncture hole 3021 is provided on one side of the puncture-resistant sealing plug 302, so that the puncture needle 5 can puncture the puncture-resistant sealing plug 302.

[0035] The diameter of the puncture needle 5 is less than 3 mm, which meets the requirement that the puncture-resistant sealing plug 302 automatically closes after puncture.

[0036] The hydrophobic filtration device 2 is a PTFE microporous membrane with a pore size of less than 0.2 micrometers to ensure solid-liquid separation.

[0037] The working principle is as follows: First, a vacuum device, such as a vacuum syringe, is used to create a negative pressure in the first chamber 101 and the second chamber 102. Then, the threaded tube 401 is connected to the brine sampling pipe. When brine sampling is required, the puncture-resistant sealing plug 302 (which seals the first chamber 101) is aligned with the puncture needle 5, and the cylinder 1 is moved, causing the puncture needle to penetrate into the first chamber 101. Then, when the sampling pipe valve is opened, the brine in the pipe... Under negative pressure, the brine enters the first chamber 101. Subsequently, this portion of brine flows along the gas separation component 6, thereby increasing the flow path of the brine. This allows the gas in the brine to disperse and pass through the hydrophobic filter device 2 into the second chamber 102, achieving gas-liquid separation. Then, the sampling needle of the gas chromatograph is inserted into the second chamber 102 through another puncture-resistant sealing plug 302 (this puncture-resistant sealing plug 302 is used to seal the second chamber 102) to detect the methane content.

[0038] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A gas collection device for brine samples, comprising a cylinder (1), characterized in that: A hydrophobic filter device (2) is fixed inside the cylinder (1). The cylinder (1) is divided into a first cavity (101) and a second cavity (102) by the hydrophobic filter device (2). A gas separation component (6) is arranged in the first cavity (101) along the length direction. A sealing device (3) is arranged on both sides of the cylinder (1). The sealing device (3) includes a puncture-resistant sealing plug (302) fixedly connected to the cylinder (1) and a puncture needle (5) for puncturing the puncture-resistant sealing plug (302).

2. The gas collection device for brine samples according to claim 1, characterized in that: The gas separation assembly (6) includes a spiral guide plate (601), the outer edge of which is fixedly connected to the inner wall of the first cavity (101).

3. The gas collection device for brine samples according to claim 2, characterized in that: The gas separation assembly (6) also includes a rod (602) that passes through the center of the spiral guide plate (601) and is fixedly connected to the spiral guide plate (601).

4. The gas collection device for brine samples according to claim 1, characterized in that: The sealing device (3) further includes a threaded cap (301), which is threaded to the end of the cylinder (1), and the puncture-resistant sealing plug (302) is located inside the threaded cap (301).

5. The gas collection device for brine samples according to claim 1, characterized in that: A puncture hole (3021) is provided on one side of the puncture-resistant sealing plug (302).

6. The gas collection device for brine samples according to claim 1, characterized in that: One end of the puncture needle (5) is fixedly connected to the feed tube (4), and one end of the feed tube (4) is fixed to the threaded tube (401).

7. The gas collection device for brine samples according to claim 1, characterized in that: The diameter of the puncture needle (5) is less than 3 mm.

8. A gas collection device for brine samples according to claim 1, characterized in that: The hydrophobic filtration device (2) is a PTFE microporous membrane with a pore size of less than 0.2 micrometers.

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