Source Location And Fracture Mechanism Inversion In Anisotropic Media Based On Acoustic Emission Experiments

Microseismic monitoring technology has been widely applied in many fields,such as oil and gas reservoir development,reservoir reconstruction and so on.However,the accuracy of location is often debatable,because the sources locate in the depths of thousands of meters underground.Therefore it is necessary to test the process of microseismic technology and focal mechanism inversion by comparing the results with the phenomenon of rock fracture based on laboratory experiments.Microseismic and acoustic emission(AE)have similar principles.And laboratory AE waveforms also exhibit some remarkable similarities with large scale seismic events.Compared with regional scale projects,laboratory AE experiment provides better signal with higher signal-to-noise ratio,stronger energy and an opportunity to evaluate the result of location and the solution of fracture mechanism inversion.In this study,an AE experiment for the lower Silurian shale sample based on the three-point bending test is used to simulate the concentrate stress destruction within the rock.Then the reliability of the process of source location and fracture mechanism inversion is tested and a brief analysis of the results is given to try to interpret the phenomenon.Through analyzing the experiment process and results,some conclusions can be reached.Firstly,the process of microseismic technology is applicable to AE signal.Secondly,most strong energy events are around the fracture,but there are also some events far away from fracture.Thirdly,anisotropic rock prefers to fracture along the forced direction,but it's possible to fracture along bedding direction.Finally,AE experiment can be a way to research or guide engineering problems by scientific testing scheme design and precise experiment operation.