A gas wellhead chemical dosing device

Abstract

This utility model relates to a gas wellhead chemical dosing device, belonging to the field of gas wellhead chemical dosing. The device includes a tank for holding the chemical agent; the upper part of the tank is equipped with a dosing pipeline and a venting pipeline; the lower part of the tank is equipped with a chemical outlet pipeline for connection to the wellhead; and the upper part of the tank is also equipped with a pressurization pipeline for connection to a casing test valve. This device utilizes the energy of the gas in the gas well and the gravity of the chemical agent to achieve dosing, eliminating the need for additional pressurization equipment, making it convenient to operate and implement.

Description

Technical Field

[0001] This utility model relates to a gas wellhead chemical dosing device, belonging to the field of gas wellhead chemical dosing. Background Technology

[0002] During gas field development, problems such as fluid accumulation, salt buildup, and severe corrosion may occur in gas wells. Fluid accumulation increases the pressure at the bottom of the well, requiring natural gas to overcome greater pressure to flow out of the wellhead, thus limiting gas well production. Generally, foaming agents are injected into the well through the wellhead production tree to reduce the specific gravity of the fluid and maintain normal gas well production. Severe salt buildup can cause blockages in multiple areas, including the tubing, casing annulus, and boreholes, affecting gas well productivity. In such cases, injecting clean water and chemicals to prevent salt accumulation and corrosion is necessary to maintain normal gas well production.

[0003] To address the aforementioned problems, pressurized equipment is typically used to add chemicals to the casing annulus or tubing to resolve issues such as severe fluid accumulation or salt buildup in gas wells. For example, Chinese utility model patent CN204140044U discloses a portable pressurized chemical dosing device for oil wells, comprising a storage tank with a dosing port at the top and a dispensing port at the bottom. The dispensing port is connected to the wellhead, specifically to a four-way valve at the casing annulus interface. A pressure gauge and a pressure relief port are located on the upper side of the storage tank, used to monitor and release the internal pressure, ensuring smooth dosing. During operation, a dosing pump is used to add chemicals to the storage tank and pressurize it, ensuring the tank pressure is not less than the annulus pressure to guarantee the smooth settling of the chemicals. The chemicals entering the storage tank then enter the wellhead through the dispensing port, completing the entire dosing process. This dosing device requires additional pressurization equipment to inject chemicals into the gas well, making the operation complex and presenting problems with difficulty in controlling the injection pressure and injection rate. Utility Model Content

[0004] The purpose of this invention is to provide a gas wellhead chemical dosing device to solve the problems in the prior art that require additional pressurization equipment and that the injection pressure and injection speed are difficult to control.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] A gas wellhead chemical dosing device includes a tank for holding chemicals. The upper part of the tank is provided with a chemical dosing pipeline and a venting pipeline, and the lower part of the tank is provided with a chemical outlet pipeline for connecting to the wellhead. The upper part of the tank is also provided with a pressurization pipeline for connecting to a casing test valve.

[0007] This invention relates to an improved wellhead chemical dosing device. The device pressurizes gas from the casing annulus by introducing it into the tank from the top through a dosing pipeline. Once the pressure in the casing annulus and the tank is balanced, the chemical in the tank is delivered to the well through the chemical outlet pipeline at the bottom of the tank by its own weight, completing the dosing process. This device utilizes the energy of the gas in the well and the weight of the chemical to achieve dosing, eliminating the need for additional pressurization equipment. Furthermore, the flow of gas during pressurization does not affect the injection of chemical, ensuring dosing speed and efficiency. It is easy to operate and implement.

[0008] Preferably, the pressurization pipeline is connected to the upper part of the tank via a flange or welding, or is connected in parallel to the venting pipeline.

[0009] Preferably, the outlet pipeline of the agent is provided with an outlet valve and an injection valve in sequence along the direction of agent flow. A bypass branch connected in parallel with the upper cavity of the tank is connected between the outlet valve and the injection valve. A pressure control valve is installed on the bypass branch. By controlling the injection valve and the pressure control valve, the gas in the annulus of the casing is introduced into the tank, and then by controlling the injection valve and the outlet valve, the agent is injected into the annulus of the casing.

[0010] Preferably, the bypass branch is connected in parallel between the drug outlet pipeline and the pressurization pipeline.

[0011] This invention utilizes a bypass branch connecting the reagent outlet pipeline and the pressurization pipeline. By closing the pressurization control valve, the pressurization pipeline is connected to the casing test valve, and the reagent outlet pipeline is connected to the tubing test valve. Gas from the casing annulus is introduced into the tank via the pressurization pipeline, balancing the pressure between the tank and the casing annulus. Once pressure equilibrium is achieved, the outlet valve and injection valve are opened, allowing the reagent in the tank to flow into the tubing under its own weight, thus achieving dosing. Alternatively, the reagent outlet pipeline can be connected to the casing test valve, and the pressurization control valve and injection valve can be opened to introduce gas from the casing annulus into the tank, balancing the pressure between the tank and the casing annulus. Once pressure equilibrium is achieved, the pressurization control valve is closed, and the outlet valve is opened, allowing the reagent in the tank to flow into the casing under its own weight, thus achieving dosing. This device can be used for both casing and tubing dosing simultaneously, improving the utilization rate of the equipment.

[0012] Preferably, the upper shell of the tank is equipped with a pressure gauge for detecting the pressure inside the tank cavity. The pressure gauge can detect whether the pressure in the annulus sleeve is balanced with the pressure inside the tank.

[0013] Preferably, a level gauge for measuring the amount of liquid injected is provided on one side of the tank. The level gauge facilitates the determination of the amount of liquid injected.

[0014] Preferably, the dosing pipeline is provided with a funnel, and a funnel control valve is provided below the funnel.

[0015] Preferably, it also includes a movable bracket for fixing the tank. The movable bracket facilitates the movement of the tank and can also be fixed at the construction site during construction.

[0016] Preferably, the movable bracket includes a bracket for fixing and supporting the tank and parallel to the axial direction of the tank, and a roller is installed on the side of the bracket facing away from the tank. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the gas wellhead chemical dosing device according to Embodiment 2 of this utility model;

[0018] Among them, 1-first pressure valve; 2-vent valve; 3-pressure gauge control valve; 4-pressure gauge; 5-funnel; 6-funnel control valve; 7-level gauge; 8-second pressure valve; 9-second ball valve; 10-first ball valve; 11-support frame; 12-roller; 13-tank body. Detailed Implementation

[0019] In existing technologies, wellhead chemical dosing devices require additional pressurization equipment at the outlet to achieve wellhead chemical dosing, and the injection pressure and injection rate are difficult to control. To solve this problem, this invention proposes a technical solution that uses the wellhead casing pressure to provide pressure to the chemical storage tank. The hydraulic pressure of the chemical solution in the storage tank itself is used to add the chemical to the wellhead, eliminating the need for additional pressurization equipment. Furthermore, the casing gas transmission path and the chemical outlet pipeline are two independent pipelines, which are identical and do not affect each other, thus improving dosing efficiency.

[0020] Furthermore, by connecting the pressurized pipeline and the chemical outlet pipeline in parallel through a bypass branch, and by adjusting the valves on each pipeline, the process of adding chemicals to the oil pipe and the casing is integrated into the same device, which is something that existing technology cannot achieve, thus improving the utilization rate of the device.

[0021] The technical solution of this utility model will be further described below with reference to specific embodiments.

[0022] The specific embodiments of the gas wellhead chemical dosing device of this utility model are as follows:

[0023] Example 1

[0024] The wellhead chemical dosing device of this embodiment includes a tank 13 for holding chemicals. The upper part of the tank is provided with a chemical dosing pipeline, a venting pipeline and a pressurizing pipeline. The venting pipeline is provided with a venting valve 2 to facilitate the dosing into the tank. One end of the pressurizing pipeline is connected in series with the annulus pipeline of the wellhead casing to introduce gas in the annulus into the tank to balance the pressure between the tank and the annulus. The pressurizing pipeline is provided with a first pressurizing valve 1 for pressurizing the tank 13. The lower part of the tank 13 is provided with a chemical outlet pipeline for transporting the chemicals in the tank to the gas well. The chemical outlet pipeline is provided with a first ball valve 10 for introducing the chemicals into the wellhead wellhead.

[0025] In other implementations, a level gauge 7 is also provided on one side of the tank 13 to facilitate observation of the volume of the medicine in the tank and to facilitate determination of the amount of liquid to be added. In other cases, an observation window can also be provided on the tank to determine the amount of liquid to be added.

[0026] In other implementation scenarios, a funnel 5 is provided on the dosing pipeline, and a funnel control valve 6 is provided below the funnel 5.

[0027] In other implementations, the vent line is also equipped with a pressure gauge 4 to check whether the pressure in the annulus of the vent sleeve is balanced with the pressure in the tank, and to guide the opening of the first ball valve 10 to control the injection pressure. In other implementations, the vent line is equipped with a pressure gauge control valve 3. In other implementations, the control valve 3 and the pressure gauge 4 can be installed directly on the upper part of the tank 13 without being connected through the vent line. When there is no pressure gauge, the operator can reasonably estimate the pressure balance time based on the tank volume and experience.

[0028] In other implementations, a support frame 11 is provided on one side of the tank body 13 to facilitate the movement and upright placement of the tank body 13, and rollers 12 for moving the tank body are provided on the outer side of the support frame 11.

[0029] The tank 13 is transported to the gas well where chemical dosing is required via rollers 12 and support frame 11. During operation, the chemical outlet pipeline is connected to the wellhead oil pressure test valve via a hose, and the pressurization pipeline is connected to the wellhead casing pressure valve interface via a hose. The vent valve 2 and funnel control valve 6 are opened, and chemical dosing, such as foaming agent, is added to the tank 13 from the funnel 5. After addition, the vent valve 2 and funnel control valve 6 are closed. Then, the casing pressure valve and the first pressurization valve 1 are opened in sequence to allow the gas in the casing annulus to enter the tank, balancing the pressure between the tank and the casing annulus. After the pressure is balanced, the first ball valve 10 and the oil pressure test valve are opened in sequence. The chemical dosing in the tank 13 enters the tubing from the tank 13 by its own gravity, realizing chemical dosing. The injection volume and injection speed are determined by observing the level gauge 7. The first ball valve 10, the oil pressure test valve, the first pressurization valve 1, and the casing pressure valve are then closed.

[0030] Example 2

[0031] The gas wellhead chemical dosing device in this embodiment, such as Figure 1 As shown, the device includes a tank 13 for holding chemicals. The upper part of the tank is provided with a chemical dosing pipeline, a venting pipeline, and a pressurizing pipeline. The venting pipeline is provided with a venting valve 2 for facilitating the addition of chemicals to the tank. The lower part of the tank 13 is provided with a chemical outlet pipeline for transporting the chemicals in the tank 13 to the gas well. The chemical outlet pipeline and the pressurizing pipeline are connected in parallel through a connecting pipeline. The pressurizing pipeline is provided with a first pressurizing valve 1 for introducing casing annular gas on the outer side of the intersection of the pressurizing pipeline and the connecting pipeline. The connecting pipeline is provided with a second pressurizing valve 8. The chemical outlet pipeline is provided with a first ball valve 10 for introducing chemicals into the tubing or casing upstream of the chemical flow direction, and a second ball valve 9 downstream of the intersection with the connecting pipeline. The second ball valve 9 is used to introduce chemicals into the tubing or casing, or in conjunction with the second pressurizing valve, to introduce casing annular gas into the tank 13.

[0032] In other implementations, a level gauge 7 is also provided on one side of the tank 13 to facilitate observation of the volume of the medicine in the tank and to facilitate determination of the amount of liquid to be added. In other cases, an observation window can also be provided on the tank to determine the amount of liquid to be added.

[0033] In other implementation scenarios, a funnel 5 is provided on the dosing pipeline, and a funnel control valve 6 is provided below the funnel 5.

[0034] In other implementation scenarios, the venting pipeline is also equipped with a pressure gauge 4 via a tee to detect whether the pressure in the annulus of the venting sleeve is balanced with the pressure in the tank, and to guide the opening of the first ball valve 10 to determine the time for drug delivery. In other scenarios, the venting pipeline is equipped with a pressure gauge control valve 3. Without a pressure gauge, operators can reasonably estimate the pressure balance time based on the tank volume and experience.

[0035] In other implementations, a support frame 11 is provided on one side of the tank body 13 to facilitate the movement and upright placement of the tank body 13. Rollers 12 for moving the tank body are provided on the outside of the support frame 11. The rollers 12 are placed upright in the tank body 13, that is, away from the ground when working.

[0036] During operation, connect the chemical outlet pipeline to the casing pressure valve at the wellhead via a hose. Open the vent valve 2 and the funnel control valve 6, and add the chemical, such as water, into the tank 13 from the funnel 5. After adding the chemical, close the vent valve 2 and the funnel control valve 6. Then, sequentially open the casing pressure valve, the second ball valve 9, and the second pressurizing valve 8 to pressurize the tank 13 through the gas in the casing annulus. Once the pressure in the casing annulus is balanced with the pressure in the tank 13, close the second pressurizing valve 8 and open the first ball valve 10. The chemical in the tank 13 will then enter the casing annulus from the tank 13 by its own gravity, thus completing the chemical addition. Determine the amount of liquid added by observing the level gauge 7, and then close the first ball valve 10, the second ball valve 9, and the casing pressure valve.

[0037] In other implementation scenarios, the second pressurizing valve 8 is closed, the first pressurizing valve 1 is opened, and the drug is added in accordance with the method of Example 1.

Claims

1. A gas wellhead chemical dosing device, comprising a tank for holding chemicals, wherein the upper part of the tank is provided with a dosing pipeline and a venting pipeline, and the lower part of the tank is provided with a chemical outlet pipeline for connection to the wellhead, characterized in that, The upper part of the tank is also provided with a pressurization pipeline for connecting to the sleeve test valve; the agent outlet pipeline is provided with an outlet valve and an injection valve in sequence along the agent flow direction, and a bypass branch connected in parallel with the upper cavity of the tank is connected between the outlet valve and the injection valve, and a pressure control valve is installed on the bypass branch.

2. The gas wellhead chemical dosing device according to claim 1, characterized in that, The pressurization pipeline is connected to the upper part of the tank via a flange or welding, or connected in parallel to the venting pipeline.

3. The gas wellhead chemical dosing device according to claim 1, characterized in that, The bypass branch is connected in parallel between the drug outlet pipeline and the pressurization pipeline.

4. The gas wellhead chemical dosing device according to claim 3, characterized in that, A first pressurization valve for introducing annular air gas into the bushing is located on the outside of the junction of the pressurization line and the bypass branch.

5. The gas wellhead chemical dosing device according to claim 3 or 4, characterized in that, The upper shell of the tank is equipped with a pressure gauge for detecting the pressure inside the tank cavity.

6. The gas wellhead chemical dosing device according to claim 3 or 4, characterized in that, A level gauge for measuring the amount of liquid injected is provided on one side of the tank.

7. The gas wellhead chemical dosing device according to claim 3 or 4, characterized in that, The dosing pipeline is equipped with a funnel, and a funnel control valve is located below the funnel.

8. The gas wellhead chemical dosing device according to claim 3 or 4, characterized in that, It also includes a movable bracket for securing the tank.

9. The gas wellhead chemical dosing device according to claim 8, characterized in that, The movable bracket includes a bracket for fixing and supporting the tank and is parallel to the axial direction of the tank. Rollers are installed on the side of the bracket facing away from the tank.

Images