Dynamic Modeling and Validation Techniques for 3D Subsurface Interpretations - Impact on Volume and Reserve Estimates

Abstract

Summary One of the major challenges in estimating profitability and risk of potential hydrocarbon reservoirs lies in constructing accurate models of the subsurface geologic structure and performing high precision volume and reserve calculations. An innovative integrated modeling workflow is presented which significantly reduces risk and uncertainty by providing tools to validate the geological model, as well as dynamically and interactively update it, in combination with new integrated techniques to calculate highly accurate volumes which are constantly being synched with the 3D model. This workflow was tested with a case study of the Teapot Dome oilfield, a basement-cored structure from Wyoming, USA. Two scenarios were modeled in which a structural framework was constructed and volumes were estimated from a hypothetical oil reservoir. The first scenario uses a basic interpretation in combination with volume calculations based on traditional horizontal slicing techniques. The second scenario uses a model that was structurally validated and balanced in combination with a new volume calculation technique based on Direct Polyhedral volume calculations. The difference in calculated volumes for the two scenarios for this specific study is about 10–15% which indicates the order of error that can potentially be associated with common reserve estimates.