Abstract

The resource industry faces old and new problems that stem from the vagaries of rock and fluid properties. As exploration and monitoring techniques improve, the results must become more directly related to the material properties in situ. At the same time, the materials and their characteristics become more complex or “unconventional.” Today's challenges include viscous heavy oils, clays and shales, gas hydrates, tight gas sands, organic-rich shales, coals and coal-bed methane, salt, and many nonsedimentary rocks. Note that not all of the materials we must examine directly involve extractable resources: shale deformation due to stress changes is important around boreholes or compacting reservoirs; and carbon dioxide injection not only produces fluid displacements and phase changes, but also involves chemical interaction with the host matrix. In addition, to understand the important characteristics of rocks, we must employ “unconventional” measurement techniques such as polymer and surface chemistry, nuclear magnetic resonance, high-resolution X-ray imaging, molecular simulation, nano-indentation, atomic-force microscopy and scanning-acoustic microscopy, and broadband elastic measurements. In this paper, we cannot cover the complete spectrum of materials and measurements. Rather, we will describe some of the important unconventional rock properties and examine some of the techniques applied to their characterization. We hope to stimulate discussions on where technology is headed and what resources will be required in the near future to make innovations successful and the tools adequately calibrated.

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