Complexity of Hydraulic Fractures – The B-value

The distribution of moment magnitudes for a hydraulic fracture treatment is related to the complexity of the fracture network through the slope of the frequency-magnitude distribution, known as the b-value. Characterizing this complexity relates to effective field drainage and can be used to calibrate predictions of fracture-mechanical models. As the b-value is determined from the magnitude distribution, then it may be glimpsed by using only a single-well observation array. We use the example of a multi-well observation array to validate this observation. The b-value field for the treatment zone is determined and compared against the distribution of microseismic moment tensors to validate that the complexity inferred by the b-value is reflected in the distribution of mechanisms determined by inverting for the moment tensors.