CN-118143897-B - Method suitable for online maintenance of emergency cut-off valve of high-sulfur-content gas field

CN118143897BCN 118143897 BCN118143897 BCN 118143897BCN-118143897-B

Abstract

The invention relates to an on-line maintenance method of an emergency cut-off valve suitable for a high sulfur-containing gas field, which comprises the steps of S1 overriding ESDV signals in an SIS system, setting a bypass valve of a ESDV actuator to be in a local control state, pressurizing the actuator to ensure that the hydraulic pressure of the actuator is enough, enabling the valve to be in a forced shielding state, S2 cutting off ESDV instrument wind sources, decompressing an actuator air supply pipeline, disconnecting an electromagnetic valve, dismantling instrument wind connection pipelines, dismantling signal cables, dismantling actuator connection bolts, S3 respectively installing a hydraulic jack at the front end and the rear end of the actuator to push the actuator, separating a ball valve rod from a sleeve of the actuator, adjusting the actuator to a maintenance point by using a crane, S4 setting the bypass valve of the ESDV actuator to be in a remote state, measuring the pressure of a hydraulic cylinder, dismantling an actuator cylinder, opening the cylinder, replacing a piston sealing ring, and S6 recovering the actuator. The invention enables ESDV to be serviced on-line.

Inventors

FU YOU
HOU JIANFENG
XING DONGPING
BAN CHENXIN
LIU JUNJUN
WU PANPAN

Assignees

中国石油化工股份有限公司
中国石油化工股份有限公司西南油气分公司

Dates

Publication Date: 20260505
Application Date: 20221205

Claims (9)

1. The method for on-line maintenance of the emergency cut-off valve of the high-sulfur-content gas field is characterized by comprising the following steps of: S1, overriding ESDV signals in an SIS system, setting a bypass valve of a ESDV actuating mechanism to be in-situ control state, pressurizing the actuating mechanism, ensuring that hydraulic pressure of the actuating mechanism is enough, and enabling the valve to be in a forced shielding state; S2, cutting off ESDV a meter wind source, releasing pressure of an actuating mechanism air supply pipeline, powering off an electromagnetic valve, removing a meter wind connecting pipeline, removing a signal cable and removing an actuating mechanism connecting bolt; S3, respectively installing a hydraulic jack at the front end and the rear end of the actuating mechanism, pushing the actuating mechanism, separating a valve rod of the ball valve from a coupling sleeve of the actuating mechanism, and adjusting the actuating mechanism to a maintenance point by using a crane; S4, setting a bypass valve of the ESDV actuating mechanism to be in a remote state, and discharging the pressure of the hydraulic cylinder; S5, measuring the swing shaft distance of the actuating mechanism, disassembling the actuating mechanism cylinder, opening the cylinder, and replacing the piston sealing ring; S6, recovering the executing mechanism.
2. The method for on-line maintenance of an emergency shut-off valve for gas fields with high sulfur content as recited in claim 1, wherein in step S1, the actuator is pressurized with a hand pump until the actuator is immobilized.
3. The method for on-line maintenance of emergency cut-off valves for high sulfur-containing gas fields according to claim 1, wherein in step S2, a quick release valve on an actuator panel is opened to release the instrument wind pressure in the actuator cavity to 0MPa, and after no abnormal action of the actuator and no drop of hydraulic pressure are observed, the solenoid valve is powered off on an SIS cabinet.
4. The method for on-line maintenance of emergency cut-off valves for high sulfur-containing gas fields according to claim 1, wherein in step S3, a crane is firstly used for hooking an actuating mechanism, lifting is carried out for stressing a lifting rope, and then a hydraulic jack is used for pushing the actuating mechanism, so that the crane straightens the lifting rope for auxiliary matching.
5. The method for on-line maintenance of emergency cut-off valves for high sulfur-containing gas fields according to claim 1, wherein in step S3, a level gauge is placed on the actuator to cooperate with hydraulic jacks for pushing, and the two hydraulic jacks stably lift.
6. The method for on-line maintenance of emergency cut-off valves for high sulfur-containing gas fields according to claim 1, wherein in step S5, two tie rods on the cylinder are removed in advance when the cylinder is removed, two extension tie rods are replaced, and the thrust of the spring cylinder is removed through the extension tie rods.
7. The method for on-line maintenance of an emergency shut-off valve for gas fields with high sulfur content according to claim 1, wherein after step S5, an operation test and a tightness test are performed on the actuator.
8. The method for on-line maintenance of emergency shut-off valves for high sulfur gas fields according to claim 1, wherein in step S6, the actuator is set to an open state under no load prior to reinstallation of the actuator, and the actuator coupling is connected to the ball valve stem.
9. The method for on-line maintenance of emergency shut-off valves for high sulfur gas fields according to any one of claims 1 to 8, wherein prior to step S1, the valve position indicator of ESDV is disassembled, rust removal and lubrication are performed at the joint of the sleeve and the actuator, and a movable scaffold and a simple platform are erected according to the height of the ESDV actuator cylinder for maintenance.

Description

Method suitable for online maintenance of emergency cut-off valve of high-sulfur-content gas field Technical Field The invention relates to the technical field of natural gas exploitation, in particular to a method suitable for on-line maintenance of an emergency cut-off valve of a high-sulfur-content gas field. Background In some high sulfur-containing gas fields, natural gas contains highly toxic hydrogen sulfide acidic gas, in order to ensure safety of sulfur-containing natural gas gathering and transportation processes, emergency shut-off valves (EMERGENCY SHUT DOWN VALVE, ESDV) are arranged on a main flow of sulfur-containing gas and a fuel gas pipeline in the process of designing and building the production station, and are used for rapidly cutting off materials of the sulfur-containing natural gas in the production station under other emergency conditions such as pipeline medium leakage, fire explosion and the like so as to ensure safe operation of pipeline equipment. For example, each station of a gas field test production project and a rolling production construction project is provided with a hundred stations ESDV, and the ESDV mainly adopts an instrument wind air supply system or an instrument wind and hydraulic oil double-acting system to control the opening and closing of an emergency cut-off valve, and the valve is opened under normal conditions and closed under emergency conditions. In the daily production operation process, the normal operation of ESDV mainly depends on whether the instrument wind pressure of a pneumatic actuator system is in a normal range, and the valve stability is reduced due to faults such as aging of a solenoid valve, a two-position three-way valve, a pressure regulating valve and other pipeline elements of the pneumatic actuator and an instrument wind cylinder sealing ring, wherein the ESDV actuator of a test production engineering station frequently causes abrasion of a cylinder end surface copper sleeve and a screw rod, and aging deformation of the sealing ring to cause leakage of the cylinder instrument wind, which easily causes abnormal closing of ESDV, and influences the normal operation production of a gas field. Therefore, in order to eliminate hidden danger, accessories such as a sealing ring of an instrument air cylinder of the ESDV pneumatic actuating mechanism and a copper sleeve are required to be replaced, so that ESDV is prevented from being abnormally closed due to sealing failure of the instrument air cylinder. However, since the valve is a self-controlled valve at a key position, the risk of abnormal closing exists in the field treatment process, and the following problems are caused: Because ESDV is positioned at key positions such as an acid gas pipeline outlet position and a fuel gas pipeline inlet position, ESDV can only be closed for maintenance treatment under the condition that production stations or whole gas fields are stopped, and online maintenance in a normal production state can not be realized. Therefore, in order to reduce the normal influence of ESDV fault handling operation on the yield of the gas field and ensure the normal production of the gas field, an online maintenance method suitable for the emergency cut-off valve of the high-sulfur-content gas field needs to be invented. Disclosure of Invention The invention aims to provide a method suitable for on-line maintenance of an emergency cut-off valve of a high-sulfur gas field, which aims at solving the problems that ESDV used in the exploitation of the existing high-sulfur gas field in the prior art can only be closed to maintain ESDV under the condition of stopping production of a production station or a whole gas field, and on-line maintenance in a normal production state cannot be realized, and the yield of the gas field is affected. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a method suitable for on-line maintenance of an emergency cut-off valve of a high sulfur-containing gas field comprises the following steps: S1, overriding ESDV signals in an SIS (Safety interlocking System ) system, setting a bypass valve of a ESDV actuator to be in-situ control state, pressurizing the actuator, and ensuring that hydraulic pressure of the actuator is enough and the valve is in a forced shielding state; S2, cutting off ESDV a meter wind source, releasing pressure of an actuating mechanism air supply pipeline, powering off an electromagnetic valve, removing a meter wind connecting pipeline, removing a signal cable and removing an actuating mechanism connecting bolt; S3, respectively installing a hydraulic jack at the front end and the rear end of the actuating mechanism, pushing the actuating mechanism, separating a valve rod of the ball valve from a coupling sleeve of the actuating mechanism, and adjusting the actuating mechanism to a maintenance point by using a crane; S4, setting a bypass valve of the ESDV actuating mechanism to be