INTEGRATION OF MICROSEISMIC, FRACTURE DENSITY, AND CURVATURE FOR IMPROVED RESERVOIR STIMULATION

Microseismic monitoring, resistivity imaging, and curvature all help to characterize zones of induced hydraulic fracturing. In this study, these tools are integrated to assess the fracturing of a horizontal well targeting the Wolfcamp Fm. in the Permian Basin. Although each tool provides individual insights, their integration increases the reliability of characterization and prediction of reservoir stimulation.

An oil-based imaging (OBMI) tool measures the resistivity of features intersecting a wellbore, revealing bedding planes, natural fractures, and drilling-induced fractures. OBMI allows for high-resolution stratigraphic characterization from the measured bedding plane orientations. These bedding planes are extrapolated to develop near-wellbore structural models. Curvature of the structural model’s Wolfcamp layer distinguishes positive, antiformal regions under flexural extension from negative, synformal regions under compression. Typically, zones of positive curvature are targeted for their susceptibility to fracture, whereas zones of negative curvature are avoided for their resistance to fracture initiation and sustainment.

However, integration of curvature, fracture density, and microseismic reveals an additional control on the success of hydraulic fracturing in zones of positive curvature. A comparison of curvature with a natural fracture density log illustrates that a higher density of natural fracturing from previous strain correlates with reduced microseismic activity, even in areas of positive curvature. Thus, positive curvature may only be an effective target of hydraulic stimulation when natural fracture density is low, indicating the continued presence of extensional stress.