Hydraulic fracturing optimization for shale reservoirs

Gas bearing shale comprises gapping gas and adsorbed gas.Hydraulic fracturing technology is unique approach to en-hance productivity in such reservoirs.On the basis of analysis of shale reservoir properties,this paper introduces hydraulic fracturing model and technical parameters optimization applicable for shale.The study finds that hydraulic fracturing numerical model(including holo-three-dimensional model)specified for sand shale formation is not available for hydraulic fracturing analysis of shale reservoirs because fluid generally flows within beddings and natural fracture system.DFN discrete model,one 3D fracturing numerical model developed based on dynamics theory on continuously homogeneous medium and discontinuously porous inhomogeneous medium,is in-troduced to simulate either multi-fissures,asymetry fissures and discontinuous fissures in hydraulic fracturing of shale and coal-measure rocks or discontinuous fissures in natural fracture and mature fault formations.Meanwhile,casing perforation types,fracturing fluid and proppant are optimized.This finding can also be used to upgrade fractured sandstone reservoir.