Hydraulic fracture microseism simulated experiment method based on fiber grating sensing

Abstract

The invention provides a hydraulic fracture microseism simulated experiment method based on fiber grating sensing and belongs to the field of vibration detection. The method comprises steps of: (1) packaging a liquid diversion pipe in a tested model, wherein one end of the liquid diversion pipe extends out of the tested model; pasting a fiber grating sensor in a fiber grating detection device on the surface of the tested model; (2) placing the tested model on a triaxial pressure device which pushes the tested model into a pressure cabin, pressurizing an X axis, a Y axis, and a Z axis until preset pressure reaches and then stopping pressurizing and maintaining the pressure constant; (3) connecting a fluid output pipe of a hydraulic fracture device with the liquid diversion pipe on the tested module, performing water pressurization until the tested model is completely fractured; and (4) continuously acquiring a microseism signal generated in the hydraulic fracture process and caused by the fracture of the tested model by using the fiber grating sensor, converting the microseism signal into a digital signal, and saving the digital signal in a computer for later processing.

Description

technical field [0001] The invention belongs to the field of vibration detection, and in particular relates to a water fracturing micro-seismic simulation experiment method based on optical fiber grating sensing. Background technique [0002] Hydraulic fracturing is an important technical measure for oil and gas well stimulation. It is not only widely used in low-permeability oil and gas reservoirs, but also has achieved good results in the stimulation of medium and high-permeability oil and gas reservoirs. It uses a surface high-pressure pump to inject fluid into the well at a displacement that greatly exceeds the absorption capacity of the formation, and builds up high pressure at a predetermined position in the well. When this pressure is greater than the nearby ground stress and the tensile strength of formation rock, fractures will be generated near the predetermined position to increase the permeability and transmission capacity of oil and gas. During the fracture pr...

AI Technical Summary

Problems solved by technology

[0007] ②The injection speed of the injection fluid should be adjustable and controllable according to the needs. When the rock permeability is high, it needs to be injected quickly; Simulate the actual fracturing process

[0010] Due to various reasons, the existing microseismic simulation experiment methods for hydraulic fracturing simulation experiments cannot meet all the above requirements, so the degree of simulation is low

One of the important reasons is that the volume of the sensor for detecting the microseismic signal is relatively large. After the triaxial pressure is added, the sensor is not installed well or the number of installed sensors will affect the effect of the triaxial pressure.

Images