Microseismic Estimation of Permeabilities of Tight-gas Sands

The objective of hydraulic well stimulation is creating a network of fractures in a tight rock that enhance its natural permeability and make hydrocarbon production economic. As both the geometry of fractures and the permeability of treated formation influence the subsequent production, their assessment is important for development of tight-gas fields. While the fracture shapes and orientations are conventionally inferred from microseismic data acquired in the process of stimulation, here we demonstrate that the same data also allow quantifying the formation permeability. We discuss the permeability-estimation technique that utilizes the dynamics of microseismic clouds and apply it to data recoded during hydraulic fracturing of two wells drilled in the Pinedale Field, Wyoming, USA. The obtained permeabilities are then used to predict the gas rates.