From geology to production: a completion optimization case study from Cleveland Sand, Oklahoma

Abstract

Oil companies seldom acquire the necessary data to help them understand subsurface heterogeneity when they design multi- stage completions for lateral wells. In particular, well logs are rarely run in the lateral section. In the absence of such subsurface information, operators generally adhere to ‘geometric’ completion designs or equally spaced stages in the lateral section. While this approach seems reasonable and follows industry norms, it may not be very effective for heterogeneous rock (Far et al., 2015; Ashton et al., 2013; Ganguly and Cipolla, 2012). The geometric completion design may result in a limited stimulated reservoir volume (SRV) and lower well production than could be achieved with an optimized design based on subsurface information. Geoscientists, completion engineers and reservoir engineers focus on different aspects of the complex problem of fracture spacing in a horizontal well. In the comprehensive study presented in this article, the authors have developed an integrated reservoir model combining reservoir characterization, petrophysical, geophysical, drilling and completion data. A fully coupled reservoir/geomechanical simulation model was built to capture the variation in rock properties in the lateral section, and to assess the impact of this variation on the simulation of injection and production processes. This single model was used to simulate both the injection and production times for the well.