Microseismic location uncertainties of semblance-weighted stacking method: A synthetic case study

• DOI: 10.1190/igc2018-122
• Publication Date: 2018-12-17T17:00:46Z
• Authors: Zhengguang Zhao; Lutz Gross; Ruizhao Yang; Dewei Li; Lijun Deng
• Keywords: 01 natural sciences; 0105 earth and related environmental sciences

Microseismic imaging is a common technique for monitoring oilfield completion and production processes. Accurate imaging of the source location of the microseismic event is of imperative importance for accurate fracture mapping. In this study, we investigate uncertainties in the estimated locations of microseismic events given two different receiver array geometries by applying the semblance-weighted stacking location method to two simple synthetic examples.The error ellipsoid, i.e. the extent of the stack image at 50% of the maximum, is used as a relative measure of uncertainty in various directions. We illustrate how these errors are affected by the receiver array geometry itself and demonstrate that for same array sizes, reducing the number of receivers used in a monitoring project doesn't impact the estimated horizontal location of a microseismic event. We also present that a surface array with more receivers and smaller receiver spacing provides a better vertical resolution than a surface array with less receivers and larger receiver spacing.