Streamline Technology for the Evaluation of Full-Field Compositional Processes: Midale—A Case Study

Summary Traditionally, the evaluation of CO2-flooding processes is performed with finite-difference compositional-simulation models. However, compositional simulation is impractical for modeling large-scale CO2 floods because of computational run-time restrictions. In cases in which reservoir heterogeneity and fluid mobility dominate the reservoir recovery mechanism, streamline simulation offers a viable alternative to compositional simulation. The "reduced" physics in streamline simulation allows field-scale CO2-flood modeling to be feasible, as long as the streamline pressure/volume/ temperature (PVT) model can be calibrated so that the streamline model will produce accurate results for CO2-injection processes. Using streamline simulation allows for the evaluation of multiple full-field development scenarios that otherwise would not be possible with compositional simulation. The objective of the study was to provide CO2-flood performance forecasts under various full-field development scenarios for the Midale field. This paper focuses on the methodology and results from the 1,000-well, >400,000-gridblock, 45+-year streamline simulation of the Midale field. In particular, it discusses the construction and history match of the full-field model, the calibration of the streamline model with the compositional model, and the development of the full-field CO2 forecasts.