Method and system for monitoring oil-gas pipeline in mining subsidence area and system constructing method

Abstract

The invention discloses a method and a system for monitoring an oil-gas pipeline in a mining subsidence area and a system constructing method. The method comprises the following steps of: monitoring axial strain of a pipe body with a fiber grating strain sensor, monitoring pipe-soil relative replacement with a fiber grating displacement sensor, and monitoring horizontal deformation of a soil body with a fiber grating sensor; demodulating and preprocessing signals acquired by the sensors, and transmitting the signals to a remote monitoring center; further analyzing and processing data in the monitoring center, and computing horizontal deformation change of a soil body on the top of the pipe in the mining subsidence area, axial strain change of the pipe body and pipe-soil relative displacement change; judging the state stabilities of the pipe body strain change and the soil body strain change, and judging whether the data surpass threshold values; when three parameter values are smaller than respective threshold values, judging that the pipeline is in a safe state; and when the axial strain of the pipe body reaches 70 percent of a pipe body limit strain value, or a pipe-soil relative displacement value reaches a threshold value and keeps constant, or a horizontal deformation curve of the soil body changes suddenly, performing pipeline safety joint early-warning.

Description

technical field [0001] The invention relates to an oil and gas pipeline monitoring method and system in a goaf subsidence area and a construction method of the system based on optical fiber grating sensing technology, and relates to the technical fields of stress measurement, temperature measurement, similar linear dimension measurement and pipeline system. Background technique [0002] The space formed after the underground mine is mined is called the goaf. After the underground mineral layer is mined, the upper rock layer loses its support, the balance condition is destroyed, and then it bends and collapses, so that the surface sinks and deforms, causing the surface to subside and form a depression. With the continuous expansion of the goaf, the depression continues to develop and form the goaf subsidence area, which will cause damage to the above-ground or underground buildings (structures). Goaf subsidence disaster is one of the main forms of geological disasters that c...

AI Technical Summary

Problems solved by technology

[0018] Due to these advantages, in the field of geotechnical engineering, fiber grating sensors are easy to embed in rock and soil for high-resolution and wide-range measurement of internal strain and temperature. The technical advantages are very obvious, especially in the ability to obtain long-term, Reliable deformation data of rock and soil. Currently, there is no report on the joint monitoring of fiber grating sensing technology used in goaf pipe body strain, pipe-soil relative displacement, and gob laying belt soil horizontal deformation.

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