The Use of Microseismic Monitoring as a Guide for Gas Production

Numerical modelling makes it possible to consider studying microseismic events resulted from hydraulic fracturing through a synthetic model, too give us rational understandings for generation of the events and the efficiency of the fracturing process itself. The research presented in this thesis uses Discrete Element Method (DEM) approach to simulate the acoustic emissions within rock samples in order to achieve the computational modelling of the micro seismic events during hydraulic fracturing process. In terms of its relation to the fracture properties and its uses in determining the successfulness of the fracturing operation. (DEM), is used in three dimensions to create model to simulate the acoustic emission from a rock sample under stress and from an injection tests on two rock sample too. The model modifies a method that was originally developed before. The developed model was validated by comparing with the results from an experiment on Springwell sandstone under a triaxial stresses. In addition, comparison with two injection tests was performed. The program is further improved using a novel changing combination factor of event to enhance the modelling results, and to expand the application of the microseismic monitoring. The developed model offers control on the number of seismic events and the statistical distribution of the events. In addition, the source of the event predictions were similar to the real one which can lead to realistic prediction regarding the type of fracture. Furthermore, it was possible to extend the program application to predict the pore collapse sources of the acoustic emissions and the aperture of the resulted fractures. In addition, the model can predict the aperture of the fractures and the expected permeability of the fractured model. The validated model could therefore help to assess the effectiveness of a hydraulic fracturing project.