Lab research on stress sensitivity of low permeability gas reservoirs

Crustal stress is an important element which affects reservoir parameters of property,especially for reservoirs more sensitive for crustal stress.Test study indicates that,stress sensitivity of low permeability gas reservoirs exists objectively not only for dry rocks,but also rocks with irreducible water,and harm of stress sensitivity to permeability cannot be ignored.With increasing of effective pressure,permeability declines gradually,and porosity decreases according to the exponentail relations.Stress sensitivity has relationship with water saturation of reservoirs.The higher irreducible water saturation is,the more stress sensitivity is.Pore deformation of low-permeability gas reservoirs is characteristic of elastic plastic deformation.