Experimental Study on Occurrence Models of Water in Pores and the Influencing to the Development of Tight Gas Reservoir
低渗气藏储层孔隙中水的赋存模式及对气藏开发的影响

It is normal to see that some water occurs in low permeability gas reservoir which influences the gas supply ability. The paper builds a model according to the pore structure, studies the occurrence models of water in different pores and the mechanism that influences the gas flows. The paper also studies the water breakthrough condition in the gas reservoir and the influence to the gas supply ability by physical simulation method. The result shows that there are two types of water in pores, movable water and residual water, which are both determined by reservoir physical properties and gas drive pressure. Movable water mainly occurrs in the fracture and big pores, and the residual water has many occurrence models in differential pores. The result also shows that when the water body is bigger than 6.0PV in gas reservoir, it′s easy to break into the formation. After wetting, some water is remained in the pore just as residual water occupying part or whole flow path. This will make the reserves far from the well and difficult to be employed, so it will influence development of the low permeability gas reservoir.