A novel approach to quantify reservoir pressure along the horizontal section and to optimize multistage treatments and spacing between hydraulic fractures

Abstract This work presents promising results for the application of a novel approach to estimate geopressure to optimize allocation of clusters in a horizontal wellbore in an unconventional shale play using information from logging while drilling (LWD) techniques. In previous publications on this subject, the usefulness of implementing the diffusivity equation in conjunction with information from well logs to estimate geopressure in conventional and complex unconventional geological scenarios was demonstrated. In this new study, a novel approach is applied to characterize reservoir and fracture pressures along the horizontal section of a well drilled in the Southwest part of the Eagle Ford unconventional shale play. To the best of the authors’ knowledge, there is no report of estimation of pore pressure in a horizontal wellbore using theoretical principles, such as the diffusivity theory. The recorded rock properties from LWD along the horizontal section of the well serve multiple purposes. Firstly, they were introduced into the solution of the diffusivity equation as “normalized values” to obtain the pore pressure distribution. Secondly, they are employed to generate a synthetic acoustic log along the horizontal section of the wellbore to determine geomechanical properties of Eagle Ford formation. The results documented in this work demonstrate that when using this novel methodology, horizontal wells can be characterized in great detail from the standpoint of reservoir pressure and brittleness. This novel approach is effective, reliable, and can help the completion engineer to decide where to allocate the clusters (perforations) to make more efficient the multistage hydraulic fracturing jobs and improve productivity. Furthermore, geoscientists, reservoir, and production engineers will benefit from knowing reservoir pressure distribution along the path of the horizontal section of the well in more detail. As a result, a more efficient reservoir characterization is obtained to improve horizontal wellbore performance.