Performance Prediction for Non-Conventional Wells in Heterogeneous Reservoirs: From Approximate Models to Detailed Simulation

Tuesday, January 8, 2002 - 11:00am - 12:00pm
Keller 3-180
Louis Durlofsky (Stanford University)
Non-conventional wells, which include horizontal, multilateral and smart wells, offer great potential for oil recovery. Predicting the behavior of these wells is complicated because of their inherent geometric complexity, the interaction between the non-conventional well and fine scale geological features, and the potential for significant wellbore pressure effects. The choice of the appropriate modeling procedure is not always obvious, however, as different types of prediction techniques are appropriate for different applications and types of decisions. In some cases, such as in preliminary screening, risk assessment, or optimization calculations, more efficient but less accurate predictions may be the most suitable. In other cases, when a large amount of data is available, more accurate modeling procedures may be justified.

In this talk, different modeling approaches for predicting the performance of non-conventional wells in heterogeneous reservoirs will be presented. These include a semi-analytical (Green's function-based) technique, suitable for single phase flow calculations, that contains approximate representations of heterogeneity and wellbore pressure effects. For more detailed studies, accurate upscaling procedures developed for use in conjunction with general finite difference models will be described. The upscaling techniques entail the accurate determination of coarse scale single and two phase flow quantities. A number of example calculations, illustrating the level of accuracy and efficiency of the various procedures, will be presented. The appropriate use and target applications for the different types of models will also be discussed.