Pore structure and gas-water flow law of low permeability gas reservoir core

The problem is not clear that the pore structure and its effect on the gas-water flowing in low permeability gas reservoir core,so the experimental techniques are used such as physical property test,NMR,Mercury penetration,gas drive water,and so on,to research the core’s pore types,pore structure,water’s occurrence modes in the pore throat and the gas-water flow law in cores.The results show that most of the core’s pore is intergranular pore,the radius of pore throat is tiny,valve pressure is big,gradation is bad and the permeability is controlled by the radius of pore throat.When the core is fully saturated by water,there is an actuating pressure for gas flow.When the gas drive pressure is lower than the actuating pressure,then the gas can not flow freely.The water in the core occurrence with two types: movable water and residual water,when the drive pressure is increasing during gas flooding,the water’s occurrence mode will change,part of the water will be driven out,the permeability will be enhanced and the gas flow will increase.So,for low permeability containing water gas layer,it is one of the key factors to decide appropriate producing pressure drop to control the gas-water flow.The result is important for development of low permeability gas reservoir.