Analysis of factors affecting the formation of Effective Stimulated Reservoir Volume（ESRV）

Based on the results of lab experiments on Triaxial Test System，field fracturing practice，and theory analysis，this paper systematically analyzes the factors affecting the formation of complex fracture network from the aspects of brittleness, horizontal stress difference, mechanical characteristics and development degree of natural fractures, fluid viscosity and treatment parameter etc. A new parameter complex fracture network volume（or effective stimulated reservoir volume）is suggested to evaluate the stimulating degree of the reservoir. Complex fracture network volume（ESRV）reflects both effect of specific surface area, ie, total fracture area to reservoir volume, and the effect of stimulated volume by fracturing. The research shows the extending shape of fractures in reservoir is influenced by both geological factors and engineering factors.