A novel approach to identifying seismogenic structures and estimating reservoir volume based on synthetic cloud of seismicity induced by hydraulic fracturing

Abstract

Precise imaging of formed fractures and delineation of a reservoir’s boundaries within a scattered seismic cloud is complicated by inaccuracies in event location. Accurate estimate of stimulated reservoir volume (SRV) is key to evaluate fracturing performance. When reservoir volume is assessed based on dispersed locations, values tend to be overestimated. The aim of the article was to calculate SRV via seismicity induced during the course of hydraulic fracturing, solely on the basis of hypocenters and location errors. The methods for three-dimensional (3D) reservoir reconstruction combine the collapsing method, density-based spatial clustering of applications with noise, and alpha-shape estimation technique using synthetic data. The method we proposed for calculating reservoir volume based on the location of microseismic events allows for a more precise and realistic estimation. The SRV obtained using the proposed approach is approximately 14 times smaller than that obtained from the original cloud.