Full-Field Modeling Using Streamline-Based Simulation: 4 Case Studies

Abstract

Abstract Modern streamline-based reservoir simulators are able to account for actual field conditions such as 3D multi-phase flow effects, reservoir heterogeneity, gravity and changing well conditions. A streamline simulator was used to model four field cases with up to 400+ wells and 150,000+ grid-blocks. History match run times were about 1 CPU hour per run with the final history matches completed in about 1 month per field. In all field cases, a high percentage of wells were history matched within the first 2-3 runs. History matching fields with a large number of wells is quite different than matching simulation models with only a few wells. Streamline simulation not only enables a rapid turnaround time for studies, but also serves as a different yet valuable tool in resolving each of the studied fields' unique characteristics. The primary reasons for faster history matching of permeability fields using 3D-streamline technology as compared to conventional finite difference techniques are: Streamlines clearly identify which producer-injector pairs strongly communicate (flow visualization). Streamlines allow the use of a very large number of wells thereby substantially reducing the uncertainty associated with outer boundary conditions. Streamline flow paths indicate that idealized drainage patterns do not exist in real fields. It is therefore unrealistic to extract symmetric elements out of a full field. The speed and efficiency of the method allows the solution of fine scale and/or full field models with hundreds of wells. The streamline simulator honors the historical total fluid injection and production volumes exactly as there are no drawdown constraints, initially. Easy identification of regions that require modifications to achieve a history match. Streamlines provide new flow information (i.e., well connectivity, drainage volumes, and well allocation factors) that is not possible to derive from conventional simulation methods.