SPE Distinguished Lecturer Craig Cipolla Presents
Fracture Modeling, Microseismic Measurements, and Production Evaluation: What's the Role of SRV?
Craig L. Cipolla - Senior Completions Engineering Advisor, Hess
The concept of stimulated reservoir volume (SRV) was developed to provide some quantitative measure of stimulation effectiveness in the Barnett shale based on the size of the microseismic "cloud." SRV is now ubiquitous when discussing well performance and stimulation effectiveness in unconventional reservoirs. However, SRV and similar techniques provide little insight into two critical parameters: hydraulic fracture area and conductivity. Each of these can vary significantly based on geologic conditions and fracture treatment design. The concept of SRV has spawned numerous reservoir engineering models to approximate the production mechanisms associated with complex hydraulic fractures and to facilitate well performance evaluations. However, these reservoir engineering models are often divorced from the fracture mechanics that created the fracture network, a significant limitation when evaluating completion effectiveness. Additionally, the interpretation of the microseismic data and the calculation of SRV are poorly linked to the actual hydraulic fracture geometry and distribution of fracture conductivity. This presentation examines the limitations and potential misapplications of the SRV concept. This work also suggests that simplifying assumptions in many SRV-based rate transient models may lead to estimates of hydraulic fracture length and reservoir permeability that are not well suited for completion optimization. Two case histories are presented that illustrate the limitations of SRV-based well performance evaluations, while detailing the value of a more holistic approach to production evaluation and completion optimization that includes integrated hydraulic fracture modeling and reservoir simulation.