The Study Of Inflow Performance And Productivity Test In Low Permeability Reservoir

Considering low permeability bottom water reservoir and unsaturated reservoir's geologic characteristics, using Darcy formula, the IPR equation of low permeability bottom water reservoir and unsaturated reservoir considering starting pressure gradient, medium deformation and natural fracture was derived. Using statistical method, theoretical method and numerical simulation respectively, the IPR curve above is drawn. Starting pressure gradient, media deform, water cut, reservoir pressure and natural fracture are analyzed respectively to explain how the production is affected.The results show that, the IPR curve of low permeability bottom water reservoir and unsaturated reservoir contains the maximum oil production. Because of bottom water coning and media deform, the IPR curve of low permeability bottom water reservoir contains the maximum oil production. When the bottom hole flowing pressure below the bubble point pressure, because of gas evolution and media deform the IPR curve of low permeability unsaturated reservoir contains the maximum oil production. For two reservoirs above, when other conditions are same, the oil production increases with decreasing starting pressure gradient and decreasing deform factor and increasing reservoir pressure, and the maximum production's pressure increases with decreasing starting pressure gradient and increasing deform factor and increasing reservoir pressure. For the low permeability bottom water reservoir, water cut has hardly effect on the maximum production's pressure. For the low permeability unsaturated reservoir, the maximum production's pressure increases with decreasing water cut.The shared character of two kind of IPR curve above is that the curves are composed of straight line section and bending line section, bending point and extreme point. They all contain the maximum oil production. In field, it is important to keep up pressure. The research has theory direction for the reasonable development of low permeability bottom water and unsaturated reservoir.