Sensitivity study and Assisted History Matching in a shale gas reservoir using CMG.
The invention of horizontal drilling and hydraulic fracturing technologies enabled economical production from unconventional plays, including shale gas reservoirs. Unconventional reservoirs have been in development in different parts of the world, but mostly in North American region for a long time. However, drivers for well performance, completion effectiveness and physics of fluid flow, in general, are still poorly understood. This is possibly due to the fact of the fluid flow in unconventionals being affected by a range of phenomena such as non-Darcy flow behaviour, gas adsorption/desorption, stress-dependence of rock properties and fracture properties such as half-length and conductivity. Additionally, even if physics of these processes can be deciphered, there is still a need for a large amount of costly data for accurate and complete reservoir characterization. Historically, History Matching has been one of the most widely used and pragmatic options for sound reservoir management. Although, as discussed, there is a non-uniqueness and a lot of uncertainty in history matching process, it is still a viable and effective approach for reliable reservoir forecasting and development in unconventional reservoirs. In this work, we firstly developed a range of numerical models to model possible fracture distribution scenarios for a shale gas reservoir. Consequently, the performance of each built reservoir model compared against the historical data. Finally, sensitivity analysis and assisted history matching workflow have been applied to a model with the best historical data match, to further fine tune the model, with the aim of having the most reliable predictive model for a shale gas reservoir.
- project presentation
- project report
- CMG DAT files (base and alternative models for shale gas reservoir)