Experimental Investigation on the Initiation of Hydraulic Fractures from a Simulated Wellbore in Laminated Shale

Abstract Understanding the formation mechanisms of complex fracture networks is vitally important for hydraulic fracturing operations in shale formation. For this purpose, a experiment under core-plunger scale conducted to investigate impact bedding plane angle, borehole size, and injection rate on initiation behaviors laminated rock. The results rock properties demonstrate that anisotropic characteristics are reflected not only elastic modulus but also tensile strength. experiments show dip angle size have significant effects behaviors, pressure (FIP) decreases with increase those two factors. rate, by contrast, has no obvious variety regulation. above data further used validate our previously proposed fully FIP model, which shows better agreement experimental than using other models various parameter combinations. Finally, postfracturing analysis performed identify growth patterns microstructures surfaces. fractures (HFs) always grow along mechanically favorable directions, potential interaction between HFs planes mainly manifests as arrest. Meanwhile, roughness surfaces physically different from each other, turn difficulties fluid flow proppant migration. findings study can help understanding behavior corresponding morphology.