Abstract
Production Analysis is critical for operators in field development to characterize the combination of the hydraulic fracture stimulation treatment and the reservoir in order to improve completion practices and increase profitability. Typical production analysis workflows endeavor to determine the permeability and extent of the reservoir as well as the length, conductivity, and stage completion efficiency of the stimulation treatment. The advent of multi-frac horizontal wells has motivated the characterization of this combined system through fracture-fracture interference production analysis by recognizing the geometry inherent in stimulation completions. Production analysis also provides an evaluation of in-situ system permeability which in turn provides an evaluation of fracture lengths and fracture conductivity. Fracture-fracture interference and subsequent production decline provides an evaluation of reserves and recovery.
However for shale gas and shale oil reservoirs, the kerogen in organic rich shales is generally considered to be hydrophobic leading to a dual porosity system of mixed wettability including hydrophilic inorganic pores. In addition to free gas production in the matrix, there is a significant contribution to reservoir performance due to the presence of adsorbed gas production. This work focuses on a comprehensive simulation-based study to quantify these effects in order to enhance our ability to characterize shale reservoirs from production trends. To account for multicomponent fluids in shale oil reservoirs, we also employ a compositional equation-of-state model to investigate the influence of natural fractures and adsorption on production performance.
