The Non-Darcy flow mathematic model with fluid-solid coupled of fractured vertical well pattern in thin inter-bedded reservoirs

摘要

Thin inter-bedded low permeability reservoir is sand layer alternating with mud layer and seriously longitudinal heterogeneous. Fluid flowing in this reservoir presents non-linear seepage characteristics. The dynamic models of porosity and permeability were deduced by the concept of bulk strain. Based on flow field partition principle, oil flow field of overall fractured cross-row well pattern could be divided into four units. Each unit could be divided into three regions with different flow mechanisms. Considering non-Darcy flow and fluid-solid coupled, a mathematical model was established for overall-fractured well pattern in thin inter-bedded reservoirs. The results show that production of well pattern with fluid-solid coupled effect is less than that without. Production of thin inter-bedded reservoir grows with the increase of the ratio of net pay thickness to gross thickness (NTG). With increasing semi-length of hydraulic fracture, production of overall fractured well pattern increases with decreasing increment. The more starting pressure gradient, the smaller production of well pattern in thin inter-bedded low permeability. When the starting pressure gradient exceeds 0.01MPa/m, it influences the production remarkably.