Abstract

Unconventional reservoirs have revolutionized the global resource supply picture and represent significant opportunities for countries around the world. Whether rock matrix or fluid properties deviate from what we may consider conventional, success in this environment requires a close integration between both subsurface characterisation and efficient engineering practices. Among the disciplines involved, geophysics plays a role in describing the sub-surface and where to develop: rock type, fluids and fractures through seismic-derived attributes. The ability to convert amplitudes from seismic into a desired rock property attribute isolated from other properties depends on: 1) the rocks and fluids under investigation, 2) acquiring and processing high quality seismic indicative of the reflection process deep underground, and 3) the particular model used for wave propagation and reflections in the earth. Microseismic, as a technqiue which monitors changes in stress, provides a guide to how the reservoir responds dynamically to stimulation and production. Based on the same wave propagation in the earth, the two techniques are linked and complimentary. Due to the heterogeneity associated with unconventional reservoirs and their depositional environments, data acquisition choices are key to unlocking detailed and robust information about the rocks and fluids through processing and analysis. Factors important for the long-term technology vision required for unconventional reservoir development are acquisition market solutions and thinking in the industry: equipment being developed and its suitability for operations in different land environments with the intensity we desire. We recognize that efficient and cost effective dense sampling of sources and receivers is what we wish to aim for. Dense spatial sampling stabilizes the higher-order attributes we need, and a more complete description of the elastic earth provides complimentary information using P- and S-waves acquired with multi-component sensors. While BP and the industry are working on the efficiency side, we need to continue to think of novel ways to produce the right equipment in large quantities such that adequate 5D wavefield sampling becomes practical.

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