A novel model for oil reservoirs considering stress sensitivity and dynamic relative permeability

Stress sensitivity and dynamic relative permeability are undeniable phenomenon in oil reservoir numerical simulation. In this paper, a complex two-phase flow model was established considering the deformation of porous media and relative permeability dynamic changes during water injection. A sensitivity analysis on this new model is carried out. The results reveal that stress sensitivity is a key factor that cannot be ignored when using reservoir numerical simulation to calculate water saturation. When the stress-sensitivity coefficient is not considered, the average water saturation of the model is 51.59%. When the stress-sensitivity coefficient is 0.12MPa−1, the average water saturation of the model is 48.45%. After considering stress sensitivity, the average water saturation of the model decreases by 6.1%. The water saturation difference between the new model and the traditional model is mainly reflected in the vicinity of the water injection well. Additionally, the influence of the range of changes in reservoir permeability on the calculation of water saturation by the new model cannot be ignored.