RU2568415C1 - Method of hydraulic tests of pipelines using horizontal directional drilling unit - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: method of hydraulic tests of pipelines using the directional drilling unit comprises preliminary cleaning of internal surface of the pipeline and offers using the horizontal drilling unit, the drill string with centralizers to supply into the open section of the pipeline the piston for preliminary and final cleaning of internal cavity hingedly connected with the test piston fitted with seals, pressure and noise sensors, and the check valve. Water through the drill string under test pressure is pumped into the zone between external seals of the test piston forming the zone of hydraulic tests.

EFFECT: providing safe operation, pipeline cavity cleaning simultaneously with hydraulic tests, exact locating the test failure pipeline section, including the underground one, while providing cost efficiency of the method.

1 dwg

Description

The invention relates to the field of overhaul of pipelines and can be used for hydraulic testing of pipelines both during construction and during overhaul.

When overhauling main gas pipelines, the following should be done:

- cleaning the cavity of the repaired area;

- a strength test and a leak test of a gas pipeline in a hydraulic manner [1] (Rules for the performance of work during the overhaul of gas pipelines BCH 51-1-97, clause 3.7).

A hydraulic test means a strength test and a leak test of a pipeline by creating an internal pressure in the idle section of the pipeline above the maximum working pressure for a certain time, using water as the test medium.

The main works on the hydraulic testing of the pipeline include:

- preparation for the test;

- filling the pipeline with water, removing air;

- pressure rise to the test;

- test of endurance;

- pressure relief to the project worker;

- leak test;

- pressure relief up to 0.1-0.2 MPa (1-2 kgf / cm ² );

- removal of water from the pipeline.

The pipeline is considered to have passed the strength test and leak test if the pipeline did not collapse during the strength test (large fistulas and cracks did not open), and during the leak test the pressure remained unchanged, and there were no leaks.

Pipeline cavity cleaning refers to cleaning the cavity by pulling a mechanical treatment device [2] (Code of Constructing the Gas Pipelines SP 111-34-96, paragraphs 2.8-2.10).

The disadvantage of this method are:

- the impossibility of accurately determining the location of the rush of the underground pipeline during hydraulic tests;

- the need to use large amounts of water for testing.

The aim of the present invention is to provide a method for hydraulic testing of pipelines using the installation of horizontal directional drilling, providing:

- safe conduct of work;

- cleaning the pipeline cavity simultaneously with hydraulic tests;

- accurate determination of the location of the pipeline section, including the underground, which did not pass the test;

- the efficiency of the method.

The specified goal is achieved through the use of:

- horizontal drilling rigs;

- drill string with centralizers;

- a piston for rough and fine cleaning of the internal cavity of the pipeline;

- a test piston for hydraulic testing of the pipeline,

equipped with seals, pressure sensors, noise and return

valve.

The essence of the present invention lies in the fact that the inventive method of hydraulic testing of pipelines using a horizontal directional drilling rig, which includes preliminary cleaning of the inner surface of the pipeline, according to the invention, proposes using a horizontal drilling rig, a drill string with centralizers to feed a piston into an open section of the pipeline for rough and fine cleaning of the internal cavity, pivotally connected to a test piston equipped with seals, sensor pressure, noise and non-return valve, while water through the drill string under test pressure is supplied to the zone between the external seals of the test piston, forming the zone of hydraulic tests.

The drawing shows a diagram of the implementation of the method of hydraulic testing of pipelines using the installation of horizontal directional drilling, where:

1 - pipeline;

2 - installation of horizontal drilling;

3 - drill string;

4 - centralizer;

5 - piston for rough and fine cleaning;

6 - test piston;

7 - consolidation;

8 - check valve;

9 - pressure sensor;

10 - noise sensor.

The method of hydraulic testing of pipelines using the installation of horizontal directional drilling is as follows.

In the open section of the pipeline 1, a horizontal drilling unit 2 using a drill string 3, for rigidity equipped with centralizers 4, introduces a piston for rough and fine cleaning 5, pivotally connected to the test piston 6. Water under the test pressure is supplied by a horizontal drilling unit 2 through the drill string 3 between the seals 7 of the test piston, thus, between the seals the test section of the pipeline is formed. The test piston 5 is equipped with a check valve 8, which keeps the water pressure in the test area constant. When a test section of the pipeline 1 breaks out, information from the pressure sensor 9 and the noise sensor 10 is transmitted to the operator console. The location of the defective section is determined by the length of the drill string 3. Hydraulic tests are carried out by moving the test piston through the pipeline by building up the drill string 3.

The proposed method allows you to:

- accurately determine the location of the rupture of the pipeline, including underground, not passed the test;

- reduce water consumption tenfold;

- increase the safety of work, since only a small part of the pipeline under test is under pressure.

Information sources

1. Rules for the performance of work during the overhaul of gas pipelines BCH 51-1-97, paragraph 3.7.

2. The set of rules for the construction of trunk gas pipelines SP 111-34-96, paragraph 2.8-2.10.

Claims (1)

A method of hydraulic testing of pipelines using a horizontal directional drilling installation, including preliminary cleaning of the inner surface of the pipeline, characterized in that, using a horizontal drilling installation, a drill string with centralizers, a piston is fed into the open section of the pipeline for rough and fine cleaning of the internal cavity, articulated connected to a test piston equipped with seals, pressure sensors, noise and a check valve, while water through the drill string d test pressure supplied to the area between the external test piston seals forming zone hydraulic tests.