Study on the influence of mechanical characteristics of multi-rhythm inter-salt shale oil on fracture propagation in Qianjiang formation, China

Abstract There are many inter-salt rhythmic shale reservoirs in Qianjiang sag, and the mineral composition content with different rhythms is different. The thin interbedding characteristics of oil bring technical challenges to hydraulic fracturing. Taking one well depression as an example, mechanical properties interface rock under temperature confining pressure analyzed. physical simulation test fracture propagation fracturing fluid completed, effects four factors on analyzed by numerical analysis method. results show that characteristic failure modes obvious differences. Under uniaxial triaxial compression, glauberite mudstone have high strength, salt shows plastic deformation characteristics. interbedded has clear cohesion bedding surface obtained from direct shear 0.60 MPa 0.99 MPa. morphology mainly affected development degree bedding. parameters, situ stress difference, displacement important impact longitudinal fractures. width height decrease, increase minimum horizontal principal layer, increases. crack decreases tensile strength interlayer. With injection rate 3.0 7.0 ml/min, fractures significantly. research can apply understanding mechanism formation.