Off-balance growth: A new concept in hydraulic fracturing

This paper offers a new fracturing concept that explains how and why actual hydraulic fractures deviate from the commonly accepted single-fracture growth models. It demonstrates that the fracture follows the local path of least resistance, not the global path, and this leads to substantial branching, presence of extensive shear fractures, and a growth pattern that is dominated by conditions at the tip of the propagating fracture, thus making its growth haphazard and off balance. Within each fracture, branching and shear fracturing create a complex path for the fluid flow and proppant transport, as. well as production of reservoir fluid, As A result, most hydraulic fractures are substantially shorter and narrower than the intended design and yield a suboptimal production increase because of inadequate fracture length and conductivity. Often, common well-completion designs also lead to creation of multiple fractures at the wellbore, a situation further aggravated by prevailing fracture designs. Off,balance growth can obstruct proppant flow, which may lead to screenout.