Gas recovery and alcohol injection integrated skid

Abstract

The present invention discloses an integrated skid for gas production and alcohol injection, which centrally arranges gas production pipelines and alcohol injection pipelines near gas production wells and related valves, instruments, etc. in a skid body according to the principles of optimized layout, convenient operation, space saving, and compliance with specifications, thereby realizing the functions of wellhead gas production and alcohol injection. Compared with traditional non-skid-mounted pipeline systems, the integrated skid has the advantages of simple installation, space saving, batch production, cost saving, and shortened on-site construction period.

Description

Technical Field

[0001] The invention relates to a medium- and low-pressure gas production and alcohol injection skid at a gas production wellhead, in particular to an integrated gas production and alcohol injection skid, belonging to the technical field of oil and gas field gas production. Background Art

[0002] The gathering and transportation technology of natural gas fields is divided into high-pressure gas gathering and medium- and low-pressure gas gathering. The high-pressure gas gathering technology is suitable for high-yield and stable-yield gas fields, while the medium- and low-pressure gas gathering technology is suitable for low-yield gas fields. In the later stage of high-yield gas fields, the gas volume decreases and the pressure decreases, and they can also be transformed to use the medium- and low-pressure gas gathering technology.

[0003] Hydrates are easily generated during natural gas gathering and transportation due to temperature and pressure changes, which can clog equipment, valves and pipelines. To prevent the formation of hydrates, heating furnaces or adding hydrate inhibitors such as methanol are generally used in engineering practice. Since it is easier to prevent hydrates by injecting alcohol, its application has gradually become popular in recent years.

[0004] In the production process using medium and low pressure gas gathering and centralized alcohol injection technology, the gas production pipeline and alcohol injection pipeline of the well site are generally laid side by side to enter the well site. The construction of the gas production pipeline and alcohol injection pipeline of the well site first requires the design of the process, pipelines, and instruments. The layout design of the gas production pipeline and alcohol injection pipeline and related instruments and valves should be carried out according to the actual distribution of gas wells; secondly, the well site is generally far away from towns and villages, and the supply of water, electricity, etc. is difficult, making the construction difficult. The traditional non-skid installation method, on the one hand, increases the workload of the early design and wastes the construction period; on the other hand, it increases the amount of on-site construction in the later stage and prolongs the construction period.

[0005] The gas extraction and alcohol injection pipes are integrated into one skid body, which can greatly reduce the workload of design and construction site, speed up the construction speed and save construction costs. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a space-saving integrated gas production and alcohol injection device which is easy to be mass-produced in a set, so as to reduce the construction of gas production and alcohol injection pipelines in gas production wells.

[0007] In order to solve the above technical problems, the gas production and alcohol injection integrated skid of the present invention comprises a gas production pipeline and an alcohol injection pipeline, wherein the gas production pipeline comprises a straight-through throttle valve, the outlet of the straight-through throttle valve is connected to the inlet of a bimetallic thermometer I after being expanded through a reducer, the outlet of the bimetallic thermometer I is connected to the inlet of a pressure transmitter I, the outlet of the pressure transmitter I is connected to the inlet of an emergency shut-off valve, the outlet of the emergency shut-off valve is connected to the inlet of a throttle valve I, the outlet of the throttle valve I is connected to the inlet of a Y-type filter I, the outlet of the Y-type filter I is connected to the inlet of a swirl flowmeter, and the outlet of the swirl flowmeter is connected to the inlet of a throttle valve II; the alcohol injection pipeline comprises a flange I, the flange I The outlet is connected to the inlet of the isolation valve I, the outlet of the isolation valve I is connected to the inlet of the Y-type filter II, the outlet of the Y-type filter II is connected to the inlet of the target flow meter, the outlet of the target flow meter is connected to the inlet of the isolation valve II, the outlet of the isolation valve II is connected to the inlet of the isolation valve III, the outlet of the isolation valve III is connected to the inlet of the check valve, the outlet of the check valve is respectively connected to the inlet of the isolation valve V and the inlet of the isolation valve VI, the outlet of the isolation valve V and the outlet of the isolation valve VI are respectively connected to the inlet of the flange II and the inlet of the flange III; the outlet of the flange I is also connected to the inlet of the pressure gauge, the outlet of the pressure gauge is connected to the inlet of the isolation valve IV, and the outlet of the isolation valve IV is connected to the outlet of the isolation valve II or the inlet of the isolation valve III.

[0008] In the above technical solution, the outlet of the emergency shut-off valve is also connected to the inlet of throttle valve III, the outlet of throttle valve III is connected to the inlet of bimetallic thermometer II, the outlet of bimetallic thermometer II is connected to the inlet of pressure transmitter II, and the outlet of pressure transmitter II and the outlet of throttle valve II are connected to a three-way valve.

[0009] In the above technical solution, a valve I is connected between the outlet of the check valve and the inlet of the metal thermometer I.

[0010] In the above technical solution, a valve II is connected between the outlet of the isolation valve IV and the inlet of the throttle valve III.

[0011] In the above technical scheme, isolation switches are arranged between the output end of the bimetallic thermometer I and the input end of the pressure transmitter I, between the output end of the Y-type filter I and the input end of the spiral vortex flowmeter, and between the output end of the isolation valve I and the input end of the Y-type filter II.

[0012] In the above technical solution, the gas production pipeline and the alcohol injection pipeline are both arranged on the skid-mounted base and the steel support frame above it.

[0013] In the above technical solution, the skid-mounted base is a frame structure covered with a patterned steel plate.

[0014] The integrated skid for gas recovery and alcohol injection of the present invention has the following advantages.

[0015] 1. Skid-mounted design. Wellhead gas production, alcohol injection pipelines, valves, and instruments are integrated into one skid, which simplifies the design, reduces the amount of preliminary design and later on-site construction, and shortens the construction period.

[0016] 2. Improved flexibility of alcohol injection. Different alcohol injection locations can be selected according to seasonal changes. In winter, when the temperature is low, high-pressure injection can be selected before the throttle valve; in other seasons, injection can be selected after the throttle valve as needed.

[0017] 3. Adapt to different gas production. According to the gas production, two specifications of gas production and alcohol injection skids are designed to cope with different gas well production conditions.

[0018] 4. The size of the skid is small. The layout inside the skid is compact and reasonable, and some connections are made by direct connection of pipe fittings and multi-layer layout, which greatly reduces the size of the skid.

[0019] 5. The skid base is lightweight. The skid base adopts a square steel frame with an outer patterned steel plate and a lifting lug structure, abandoning the solid thick steel plate base method, reducing the overall weight of the skid and facilitating transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a top view of the structure of the gas production and alcohol injection integrated skid.

[0021] Figure 2 This is a three-dimensional diagram of the integrated skid for gas production and alcohol injection. DETAILED DESCRIPTION

[0022] There are two designs of gas collection and alcohol injection integrated skids, one with a gas collection line nominal diameter of DN50 and the other with a gas collection line nominal diameter of DN40. The appropriate size can be selected according to the size of the gas source.

[0023] like Figure 1 and 2 As shown, the technical solution adopted by the present invention is as follows:

[0024] The gas production pipeline and the alcohol injection pipeline are concentrated in one skid through optimized layout. The gas production pipeline includes: natural gas enters from the straight-through throttle valve 28, the straight-through throttle valve 28 is followed by a large and small head expansion and then a bimetallic thermometer Ⅰ24, the bimetallic thermometer Ⅰ24 is followed by an intelligent pressure transmitter Ⅰ22, the intelligent pressure transmitter Ⅰ22 is followed by an emergency shut-off valve 21, and then the pipeline is divided into two routes, the main route is arranged with a throttle valve Ⅰ20, a Y-type filter Ⅰ19, an intelligent swirl flowmeter 18, and a throttle valve Ⅱ17 in sequence; the bypass is arranged with a throttle valve Ⅲ16, a bimetallic thermometer Ⅱ15 and an intelligent pressure transmitter Ⅱ14 in sequence; the main and bypass pipelines are connected and merged into one pipeline through a three-way valve 27 after passing through the throttle valve Ⅱ17 and the intelligent pressure transmitter Ⅱ14, and are connected to the gas production line outside the skid through a flange.

[0025] The alcohol injection pipeline includes: the alcohol injection agent outside the skid enters the skid body through flange Ⅰ1, and is divided into two main and bypass routes. The main route is arranged with isolation valve Ⅰ3, Y-type filter Ⅱ4, target flowmeter 5, isolation valve Ⅱ6 in sequence. The target flowmeter 5 measures the amount of alcohol injection, and isolation valve Ⅰ3 and isolation valve Ⅱ6 are respectively arranged before and after it to facilitate the maintenance of the flowmeter; the bypass is arranged with pressure gauge 2 and isolation valve Ⅳ7 in sequence, and isolation valve Ⅳ7 and isolation valve Ⅱ6 are connected to isolation valve Ⅲ8. The isolation valve Ⅱ6 and isolation valve Ⅲ8 are connected to the gas production pipeline through valve Ⅱ26 to facilitate opening valve Ⅱ26 to inject alcohol into the gas production pipeline when necessary, ensuring the flexibility of alcohol injection. The main route and the bypass are then merged together and connected to the check valve 9 through the isolation valve Ⅲ8. After the check valve 9, the alcohol injection pipeline is divided into three branches. Two branches are connected to the gas production tree through the isolation valve V10 and the isolation valve VI12 to connect the flange II11 and the flange III to inject alcohol into the gas production tree. The other branch is connected to the gas production pipeline through the valve I25 to inject alcohol into the gas production pipeline when necessary.

[0026] Isolation switches 23 are installed on the pipelines between the bimetallic thermometer Ⅰ24 and the intelligent pressure transmitter Ⅰ22, between the Y-type filter Ⅰ19 and the inlet of the intelligent vortex flowmeter 18, and between the isolation valve Ⅰ3 and the Y-type filter Ⅱ4 to facilitate inspection and maintenance of the pipelines.

[0027] The gas production pipeline and the alcohol injection pipeline are centrally arranged on the skid-mounted base 29 and the square steel support frame on the base, together forming a complete skid structure. Among them, the base 29 is a frame structure covered with a patterned steel plate to reduce the weight of the skid.

[0028] The gas recovery and alcohol injection integrated skid has the following working modes.

[0029] Mode 1: Under normal working conditions, after natural gas is produced from the gas well, it flows through the straight-through throttle valve 28 to throttle and reduce the pressure, and the temperature is measured by the bimetallic thermometer Ⅰ24, and the pressure is measured by the intelligent pressure transmitter Ⅰ22. It continues to flow through the emergency cut-off valve 21, and then the flow is measured by the intelligent swirl flowmeter 18. Finally, it is connected to the external transmission pipeline through the three-way valve 27 and transported to the gas gathering station. The alcohol injection agent enters the skid through the alcohol injection pipeline inlet, and the pressure is measured by the pressure gauge 2, and the flow is measured by the target flowmeter 5. It is divided into two streams and flows out of the skid from the alcohol injection pipeline outlet flange Ⅱ11 and flange Ⅲ13 respectively, and enters the gas tree to achieve high-pressure alcohol injection.

[0030] Mode 2: In winter, the temperature is relatively low and a large amount of alcohol injection is required. At this time, valve Ⅱ26 is opened and the alcohol injection agent can be injected from the bypass where valve Ⅱ26 is located, thereby injecting alcohol in three ways together with the alcohol injection pipeline outlet flange Ⅱ11 and flange Ⅲ13.

[0031] Mode 3: In areas with severe climates, when the temperature is extremely low for a period of time, a larger amount of alcohol injection is needed. At this time, open valve Ⅰ25 and valve Ⅱ26, and the alcohol injection agent can inject alcohol from the bypass where valve Ⅰ25 and valve Ⅱ26 are located, thereby injecting alcohol in four ways together with the alcohol injection pipeline outlet flange Ⅱ11 and flange Ⅲ13.

[0032] Mode 4: The intelligent vortex flowmeter 18 fails. At this time, the throttle valve III 16 is manually opened, and the throttle valve II 17 and the throttle valve I 20 are closed. After the natural gas comes out of the emergency shut-off valve 21, it flows through the bypass through the throttle valve III 16, the bimetallic thermometer II 15, and the intelligent pressure transmitter II 14, and enters the three-way valve 27 and flows out. Under this working condition, the intelligent vortex flowmeter 18 can be repaired without affecting production.

[0033] Mode 5: The straight-through throttle valve 28 fails, and the emergency shut-off valve 21 is automatically shut off to prevent high-pressure natural gas from entering the low-pressure pipeline after throttling, causing pipeline system safety problems.

Claims

1. Gas production and alcohol injection integrated skid, including gas production pipeline and alcohol injection pipeline, characterized by: The gas production pipeline includes a straight-through throttle valve, the outlet of the straight-through throttle valve is connected to the inlet of bimetallic thermometer I after being expanded through a reducer, the outlet of bimetallic thermometer I is connected to the inlet of pressure transmitter I, the outlet of pressure transmitter I is connected to the inlet of emergency shut-off valve, the outlet of emergency shut-off valve is connected to the inlet of throttle valve I, the outlet of throttle valve I is connected to the inlet of Y-type filter I, the outlet of Y-type filter I is connected to the inlet of swirl flowmeter, and the outlet of swirl flowmeter is connected to the inlet of throttle valve II; the alcohol injection pipeline includes a flange I, the outlet of flange I is connected to the inlet of partition valve I, and the outlet of partition valve I is connected to the inlet of Y-type filter I. The end is connected to the inlet of Y-type filter II, the outlet of Y-type filter II is connected to the inlet of target flow meter, the outlet of target flow meter is connected to the inlet of isolation valve II, the outlet of isolation valve II is connected to the inlet of isolation valve III, the outlet of isolation valve III is connected to the inlet of check valve, the outlet of check valve is respectively connected to the inlet of isolation valve V and the inlet of isolation valve VI, the outlet of isolation valve V and the outlet of isolation valve VI are respectively connected to the inlet of flange II and the inlet of flange III; the outlet of flange I is also connected to the inlet of pressure gauge, the outlet of pressure gauge is connected to the inlet of isolation valve IV, and the outlet of isolation valve IV is connected to the outlet of isolation valve II or the inlet of isolation valve III; The outlet of the emergency shut-off valve is also connected to the inlet of the throttle valve III, the outlet of the throttle valve III is connected to the inlet of the bimetallic thermometer II, the outlet of the bimetallic thermometer II is connected to the inlet of the pressure transmitter II, and the outlet of the pressure transmitter II and the outlet of the throttle valve II are connected to a three-way valve; A valve I is connected between the outlet of the check valve and the inlet of the metal thermometer I; Isolation switches are arranged between the output end of the bimetallic thermometer I and the input end of the pressure transmitter I, between the output end of the Y-type filter I and the input end of the swirl flowmeter, and between the output end of the isolation valve I and the input end of the Y-type filter II.

2. The integrated skid for gas recovery and alcohol injection as claimed in claim 1, characterized in that: A valve II is connected between the outlet end of the isolation valve IV and the inlet end of the throttle valve III.

3. The integrated skid for gas recovery and alcohol injection as claimed in claim 1, characterized in that: The gas production pipeline and the alcohol injection pipeline are both arranged on a skid-mounted base and a steel support frame above it.

4. The integrated skid for gas recovery and alcohol injection as claimed in claim 3, characterized in that: The skid-mounted base is a frame structure covered with a patterned steel plate.

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