The unconventional reservoirs are commonly recognized by their robust velocity anisotropy, low porosity and exceptionally low permeability that requires hydraulically induced fractures or other means of enhanced oil recovery techniques for economically viable production and acceptable recovery efficiencies. While there is significant advantage for applying these stimulation methodologies for economical production rates in shale reservoirs, these operations introduce concern on potential for surface and groundwater contamination as well as air pollution issues that is utmost essential for careful research for preventing and mitigating any environmental and safety issues.
Microseismic monitoring has gained significant popularity in recent years as a unique tool for monitoring the Stimulated Reservoir Volume (SRV) during and after the fracturing operations. The advancements made on data acquisition and interpretation enable us to utilize the unique monitoring capability of the microseismic data to understand the parameters controlling the shale reservoir complexities, the fracture initiation, propagation and interaction of the induced fractures with the natural fractures by extracting time dependent variables needed for the coupled flow and geomechanical models. As the magnitude of the microseismic events and their special distributions are strongly influenced by the stress regime the reservoir formation is located and the alterations caused by the fluid injection and fracturing processes, micro seismic provides valuable insight into the stress regime during the recording of the events in addition to identification of the low strength intervals in any reservoir and seal formation. The high fluid sensitivity of the shale formations is a priority specifically for shales that needs to be brought into the analysis for maximizing the advantages we could gain utilizing the microseismic monitoring techniques.