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

An oil and gas pipeline, large-diameter technology, applied in the application of stable tension/pressure to test the strength of materials, by measuring the acceleration and deceleration rates of fluids, and using liquid/vacuum for liquid tightness measurement, etc. It can solve problems such as pipeline bursting , to achieve the effect of convenient operation, clear principle and simple structure

CN102494952AInactive Publication Date: 2012-06-13SOUTHWEST PETROLEUM UNIV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2012-06-13
Estimated Expiration
Not applicable · inactive patent

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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.
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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...

Examples

Embodiment Construction

[0027] according to figure 1 As shown, the pipeline is laid in a high drop area, assuming that the maximum elevation difference in the pipeline is H max 100m, pipe outer diameter D It is 1219mm, the wall thickness is 18.4mm, and the construction site temperature is 20°C. Before the pressure test on the main line 9, install a pressure gauge 5 on the pressure test head A6 at the drain end, weld a branch pipe on the pressure test head A6 and install a high pressure gate valve A7, and install a drain on the outlet end of the high pressure gate valve A7. Pipe 8, and then weld a branch pipe to the pressure test head B2 at the other end of the main line 9 and install the high pressure gate valve B3. After the pressure test is completed, the high pressure gate valve A7 and the high pressure gate valve B3 are in a closed state.

[0028] Choose the air compressor 1 with appropriate displacement and rated discharge pressure, and the rated pressure of air compressor 1 P not lower than ,amon...