Research On Porosity And Permeability Evolution Of Fractured Reservoir Under Dynamic Stress Field

In the progress of practical among well fluid, the injection-production time drives and theworking system of injection-production changes. Target zone pore pressure varies constantly.Which cause reservoir pressure to new abundance and dynamic change. At the same time,pore pressure caused the change of formation stresses, which is the damage to the stadiumrock effected by the dynamic stress filed. Stadium rock permeability must change with theaccumulation of rock damage. People have not found the appropriate and effective former todescribe the whole process now. Building the effective injection and production dynamicstress rock evolved model is significant to draw up new exploitation plan, which is magnifiedto well-net array and build the increasing measurement of production especially. The modelcan utility predicts that the stadium rock permeability varies as the time for the variety of thedevelopment of talent system. It also can learn the diversity of states rock rating and thenstrengthen oil recovery, improve oil recovery, prolong the fixed number of years of oil fieldexploitation. The discovery is initiative quid significant to water project, tunneling,underground storage project and other engineering areas, which are value of theory andutilization.The paper study object is formation rock including natural crack. The purpose is buildingporosity and permeability evolution model in the dynamic stress field. The damage is thebridge between porosity and permeability evolution and stress field. The paper sets of porepressure first of all, study the alternation of dynamic stress field formation pore pressurealong with time. Set up the mode of dynamic stress field changes with time. Next utilize thedamage force theory set up fractured rock constitutive equation, establish fracture propagationmode, moreover derive fracture rock damage evolution stress and strain equation. Ultimatly,set up the coupled the damage field and Seepage field at the base of predecessors study.Obtained fractured rock masses dynamic stress field porosity and permeability evolutionmode with time.