A NEW METHOD FOR MODELING PHASE BEHAVIOR OF HYDROCARBONS PRODUCED IN SHALE OIL RESERVOIRS

摘要

This paper presents a novel method that quantifies thepore confinement effects on reservoir fluid propertiesand phase behavior of hydrocarbons in shale oilreservoirs. The method takes into account the rock poresize distribution derived from core or logmeasurements. The new method is applied to quantifythe effects of pore size distribution on fluid saturation,compressibility, and viscosity. The reservoir fluid PVTdata are generated to perform dynamic simulation toquantify the influence of pore confinement on reservoirpressure, fluid saturation distributions, GOR, and oilrecovery factors. The dynamic simulation studies areconducted for shale oil reservoirs, including Bakkenshale oil formation. Primary sensitivity analysis resultsshow that the pore confinement has no significant effecton oil recovery factors in shale oil reservoirs. Matrixpermeability, hydraulic fracture length and spacing, andthe properties of the natural fracture system are the keyparameters governing hydrocarbon recovery and phasebehavior in shale oil reservoirs.