Explosive fracture studies on oil shale

Fracture, fragmentation, and/or enhanced permeability through explosive methods can be difficult to achieve in the often restricted environment demanded of in situ resource recovery methods. Blasting to confined volumes and the need for uniform fragment size and permeability adds a dimension for which a history of blasting experience is not available. Computer modeling offers a potential tool for rapid evaluation and optimization of the explosive and geometry parameters, providing material models are available which adequately describe the blast phenomena and material response. Fracture and fragmentation studies have been conducted on oil shale which couple controlled small scale fracture testing with larger scale explosive blasting experiments. Specifically, plate impact, capacitor discharge, Hopkinson bar, and small-scale cylindrical He methods have been used to assess the dependence of fracture stress, fracture energy, and fragment size on the rate of loading. These studies have suggested appropriate models descriptive of the rate-sensitive fracture phenomena, and these models have been incorporated into one- and 2-dimensional computer codes. 20 references.