A review of the microseismic focal mechanism research

Abstract

Reservoir reconstructions implemented in unconventional oil and gas exploration usually adopt hydraulic fracturing techniques to inject high-pressure fluid into the reservoir and change its pore-fracture connection structure to enhance production. Hydraulic fracturing changes the reservoir stress and causes the rocks to crack, thus generating microseismic events. One important component of microseismic research is the source mechanism inversion. Through the research on the microseismic focal mechanism, information on the source mechanisms and in-situ stress status variations can be quantitatively revealed to effectively optimize the reservoir reconstruction design for increasing production. This paper reviews the recent progress in hydraulic fracturing induced microseismic focal mechanism research. We summarize their main principles and provide a detailed introduction of the research advances in source modeling, microseismic data synthesis, and focal mechanism inversion. We also discuss the challenges and limitations in the current microseismic focal mechanism research and propose prospects for future research ideas and directions.

Experimental Study on Hydraulic Fracturing of Bedding Shale Considering Anisotropy Effects

“…where P W is the internal pressure of the wellbore fracturing fluid; σ ρ (2) , σ θ (2) , and σ z (2) are the radial stress component, circumferential stress component, and axial stress component due to the internal pressure, respectively; and σ z * is the corrected axial stress component.…”

“…With the shortage of conventional forms of energy and increasingly serious environmental problems, shale gas, as a clean energy, has important industrial value and strategic significance. − The core technology in the exploitation of shale gas is hydraulic fracturing. Its principle is to use a high-pressure liquid to conduct volume fracturing on deep shale reservoirs to form a fracture network structure to produce stable industrial gas flow. − Owing to the tightness and low permeability of shale, the fracture network formed after fracturing is the main channel for shale gas permeability.…”

Methods for the Geophysical Exploration and Sustainable Utilisation of Coalbed Methane Resources in Abandoned Mines of Shanxi, China

“…Geophysical exploration methods are attractive for application in abandoned coal mines owing to their low cost and non-destructive detection of deep layers, and they are advantageous for characterising the geological structure, goaf distribution, and coalbed methane reservoirs of coal mines. Techniques such as the seismic method [3,4], electromagnetic method [5][6][7], high-density electrical method [8,9], induced polarization method [10], micromotion method [11,12], and radioactive detection method [13,14] have been used to accurately survey mined-out voids, water accumulation, and old workings. These methods can contribute not only to safe and efficient coal mining but also to the restoration and management of the mining environment, and they can be used to establish a geological foundation for the exploration and development of coalbed methane resources in abandoned mines [15,16].…”

Characteristics of Micro-Seismic Events Induced by Ground Collapse—A Case Study in the Rongxing Gypsum Mine in Hubei Province, China

“…The accuracy and timeliness of mature monitoring equipment, such as interferometric synthetic aperture radar (InSAR) and global navigation satellite system (GNSS), are also insufficient. The process of ground collapse deformation is mostly analyzed by surface deformation, while underground rock deformation is poorly understood [ 10 , 11 , 12 ]. Therefore, the development of stable and time-efficient monitoring technology for mining ground collapse has always been a research hotspot.…”