US-12625028-B2 - Method of monitoring of pressure and moisture content in the hollow of a decommissioned pipeline and device for implementation thereof

US12625028B2US 12625028 B2US12625028 B2US 12625028B2US-12625028-B2

Abstract

The invention relates to pipeline transportation. Technical result is represented by simplicity of implementation and increase in efficiency of monitoring of moisture content and pressure in pipeline hollows. Installation indicating cartridge filled with silica gel that allows for visual inspection of its indication, the latter is installed on the pipeline while gas circulation between the pipeline and cartridge is provided. Pressure gauge is connected to the indicating cartridge, and the latter is purged with gas from the pipeline. Value of pressure in the pipeline is determined, and in case obtained results deviate from the specified value, a conclusion on the pipeline depressurization is made. Change of moisture content of gas in the pipeline is determined by indicating cartridge color change.

Inventors

Shiryapov Dmitriy Igorevich
Lukin Sergey Aleksandrovich
Mayants Uriy Anatolievich
Alikhashkin Alexsey Sergeevich

Assignees

PUBLICHNOE AKTSIONERNOE OBSCHESTVO “GAZPROM”

Dates

Publication Date: 20260512
Application Date: 20201123
Priority Date: 20200909

Claims (1)

1 . A method of monitoring pressure and moisture content in a hollow of a decommissioned pipeline comprising: installing an indicating cartridge on a decommissioned pipeline filled with gas so that a circulation of gas between a hollow of the decommissioned pipeline and an interior cavity of the indicating cartridge is provided, wherein the indicating cartridge is formed from a transparent material and is filled in the interior cavity thereof with a silica gel, the transparent material of the indicating cartridge allowing for visual inspection of a color of the silica gel; connecting a pressure gauge to the indicating cartridge; purging the indicating cartridge of gas from the hollow of the decommissioned pipeline; within preset time intervals, recording a value of a steady state pressure in the hollow of the decommissioned pipeline from the pressure gauge, wherein the preset intervals comprise daily during a first ten days of monitoring and every fifteen days after the first ten days of monitoring; when the recorded steady state pressure deviates from a specified value by a predetermined threshold, concluding that the hollow of the decommissioned pipeline is depressurized and determining a gas moisture content change in the hollow of the decommissioned pipeline by a corresponding change in the color of silica gel in the indicating and; when the color of the silica gel in the indicating cartridge has changed to a color outside a specified colorimetric scale limit, concluding that a moisture content in the hollow of the decommissioned pipeline exceeds a predetermined allowable moisture level.

Description

This group of inventions relates to the field of pipeline transportation and can be used in preserving pipelines or other confined process equipment. Pipeline preservation is required in case commissioning of a repaired or newly built pipeline is postponed for a longer period of time or prior to disposal of this pipeline. Within this preservation period, it is necessary to carry out periodical monitoring to demonstrate pipeline tightness and initial moisture content in its hollow. For the purpose of preservation, pipelines are filled with dry inert gas until gauge pressure is achieved. Main parameter to be controlled during monitoring of a preserved pipeline is the value of pressure in the pipeline hollow. One more controlled parameter is moisture content in the pipeline hollow. Inert gas used for preservation shall be dried to a specific value of moisture content increase in which detected in the course of monitoring demonstrates either water ingress into the pipeline caused by its depressurization, or poor drying of the hollow thereof prior to preservation. There is a known method of determination of aqueous vapor content and moisture dew point (GOST 20060-83. Natural combustible gases. Methods for determining water vapour content and dew-point of moisture, p. 2-4) that includes measurement of equilibrium temperature between formation and evaporation of dew on the surface of a metal mirror in contact with the gas being analyzed. Device with which this method is implemented is represented by a dew point hygrometer. Samples are taken by connecting the device with the source of analyzed gas. Disadvantage of said method is represented by necessity to direct the flow of test gas to the device measuring chamber during measurement with flow rate of 1-3 dm3/min, and to maintain said flow rate for at least 15 minutes. Gas sampling with specified parameters from a preserved pipeline hollow can be carried out by opening stop valves, for example, on a gauge nozzle, gas sampling riser or a vent stack which, however, results in loss of gas used for preservation and, accordingly, in reduction of pressure in the preserved pipeline. Moreover, implementation of the known method provides for determination of only one parameter in the process of monitoring (moisture content). There is a known method of determination of aqueous vapor content and moisture dew point (GOST 20060-83. Natural combustible gases. Methods for determining water vapour content and dew-point of moisture, p. 7-12) that includes adsorption of water vapors by anhydrous diethylene glycol and further determination of water bound with diethylene glycol using Karl Fischer titration or gas chromatography methods. Disadvantage of this known method is represented by labor-intensive technology of measurement which is hard to implement in case of continuous monitoring at a main pipeline run, in particular, due to significant time consumption. Closest analogous solution (prototype) of the provided method is the method of maintenance of moisture condition in the inner hollow of a transported article (patent of the Russian Federation No. 2629743, B65D 88/38 published on 31 Aug. 2017) where moisture condition maintenance is provided by means of moisture adsorption from air using silica gel placed in a drying unit linked to the transported article hollow with an air duct. Prior to this, a transforming bladder with gauge pressure is placed in the hollow of the transformed article. Disadvantage of this known method is that it can be used to monitor and maintain required moisture content in the article hollow volume of which equals several tens of cubic meters, and it cannot be implemented in cross-country main pipelines (with diameter up to 1,420 mm) due to limited moisture storage capacity of available silica gel stock and its incapability to dry remote pipeline sections. Because of the same reasons, the known method cannot be implemented during monitoring of a preserved pipeline for a long period of time (up to three years). Moreover, it is impossible to use transforming pressurized bladder in the main pipeline hollow that has large linear dimensions. There is a known device for implementation of the method for control of tightness of atomic marine plant steam generators with pressurized water coolant (patent No. 2352005, G21C 17/022 published on 10 Apr. 2009) where atmospheric moisture sampling from the steam generator pipeline system is carried out by blowing air through a desiccant. To determine the tritium content in the steam generator pipeline system air, the method of adsorption atmospheric moisture sampling is used. Indicating silica gel placed in a transparent bolster made of organic glass is used as a moisture adsorbent. After sampling, moisture is extracted from silica gel by vacuum thermal desorption. Tritium activity is measured in obtained moisture using a radiometer. In case tritium content in air exceeds the measurement technique error, a conclusion on d