Drainage method for high-fall heavy-caliber oil-gas pipeline after pressure testing

Abstract

The invention relates to a drainage method for a heavy-caliber oil-gas pipeline used for paving in high-fall areas after pressure testing, which aims at solving the problem of pipeline burst caused by water attack in the drainage process of the oil-gas pipeline. The technical scheme is that the drainage method comprises the steps of firstly, selecting the model of an air compressor according to fall of a laid pipeline and the diameter of the pipeline; installing a pressure gauge and a high-pressure gate valve A connected with a drainage pipe on a pressure testing sealing head A at a drainage end of a main pipeline; enabling a pressure testing sealing head B at the other end of the main pipeline to be connected with a high-pressure gate valve B and then connected with the air compressor, wherein a pipe clearing device is arranged in the pressure testing sealing head B at this time; starting up the high-pressure gate valve A to carry out natural drainage, starting up high-pressure gate valve B when the pressure descends to early warning pressure, and starting up the air compressor to enable the pipe clearing device to clear away water; shutting down the high-pressure gate valve A when the pressure descends to the early warning pressure, stopping drainage, starting up the high-pressure gate valve A again when the pressure rises to safe drainage pressure, and continuing to clear away the water; and repeating the processes until finish. The drainage method can effectively prevent the pipeline burst, and is simple in structure and convenient in operation.

Description

Technical field [0001] The invention relates to a pressure test drainage method for a large-diameter oil and gas pipeline laid in a high-fall area after a pressure test. Background technique [0002] With the increase of domestic oil and gas pipelines, the length, diameter, and gas transmission volume of pipelines are also increasing, and the construction conditions are becoming more and more complicated. At present, oil and gas pipelines laid in high-drop areas frequently experience pipe bursts during the drainage process after pressure test, which seriously affects the pipeline laying process and threatens the safety of workers and nearby residents on the construction site. The phenomenon of pipe bursts in the process of sweeping water after pressure test is rare in the past, but with the increase of the complexity of the geographical conditions of laying pipelines, some areas of our country even have super-high drop terrain, and the diameter of pipelines is increasing. Increa...

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Problems solved by technology

[0003] The purpose of the present invention is: in order to solve the problem of pipeline burst caused by water hammer in the drainage process after the pressure test of oil and gas pipelines with high drop and large diameter, a method for pressure test and drainage of oil and gas pipelines with high drop and large diameter is proposed.

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