Book Description

Frac fluid flow, structure, and fracture mechanics simulations are developed for predicting and optimizing fracture dimensions and fluid leak-offs. Roles of in situ stress and material properties for possible vertical migration of fractures from the pay zone are discussed. Rationale for foam and dendritic fracturing experiments is presented along with numerical experiments for examining the phenomena of spalling of the fracture faces and conditions for secondary fracture initiation. Assignment of conventional, foam, cyrogenic, dendritic, and explosive fracturing treatments for specific reservoir properties is considered. Variables include fracture density and extent, shale thickness, in-situ stress gradients, energy assist mechanisms, well clean-up, shale-frac fluid interaction, proppant selection, and fracture height control. The analysis suggests that correlation with prevailing in situ stress gradients are promising diagnostic indicators for fracture treatment selection and design. In conclusion, the comprehensive development of an economical strategy requires extensive and controlled field testing with supporting predictive analyses of reservoir responses. Finite element modeling of reservoir in situ stress trajectories and the flow and fracture responses in the reservoir is recommended.