Seepage Mechanism And Application Of Tight Gas Reservoir

The tight gas reservoir has the characteristics of ultra-low permeability,low porosity and high irreducible water saturation.The special pore structure causes the fluid seepage law to be different from the conventional reservoir.This paper mainly uses the indoor physical simulation and software numerical simulation to treat the tight gas.Related studies have been carried out on the characteristics of complex seepage.The study compares the stress-sensitive characteristics of the presence or absence of irreducible water.Based on this,the influence of the pressurization method on stress sensitivity is studied.Since artificial fracturing is the main development tool in the development of tight gas reservoirs,stress-sensitive experiments with cracks and proppants were carried out.The gas flow characteristic flow experiment was carried out under the condition of the core containing bound water,and the gas starting pressure gradient was determined.The starting pressure gradient of different permeability cores under the bound water condition was measured respectively,and the empirical formula of starting pressure gradient and core permeability was found.And conducted an experimental study on the dynamic starting pressure during the development process.The gas-water two-phase relative permeability calculation model considering the starting pressure gradient and stress-sensitive effect is derived.The bound water saturation is measured by online nuclear magnetic resonance.The characteristics of gas-water two-phase relative permeability curves of reservoirs with different physical properties were studied.Finally,the experimental results are applied to the numerical simulation of single well productivity.The stress sensitivity characteristics and starting pressure obtained under different experimental conditions are considered as the influence of fixed value on gas well productivity.