NSF Award
2138930
The broader impact/commercial potential of this I-Corps project is to develop an apparatus to measure the swelling of clay-rich geologic formations, such as mudstones or shales. Accurate knowledge of shale swelling is required for the design of wellbores drilled for hydrocarbon or geothermal exploration and for the long-term seal integrity monitoring for carbon dioxide storage in subsurface formations. Inaccurate measurement of shale sensitivity to water can cause problems such as wellbore collapse, pipe sticking, bit balling, unintended fracture growth to neighboring formations, or carbon dioxide leakage with economic and environmental consequences. The proposed optical swell-meter may help drilling engineers, production engineers, and mud loggers in operating and service companies, oil field laboratories, and government regulatory agencies to obtain an accurate measurement of shale swelling.<br/><br/>This I-Corps project investigates the commercial feasibility of a new optical swell-meter apparatus for the measurement of shale swelling. This apparatus applies the principles of digital image correlation (DIC) techniques on the pictures taken from a rock sample painted with a speckled pattern and submerged in water. Comparing the pictures taken at different time intervals with the original picture using DIC techniques, the deformation of the rock sample can be measured. The proposed device provides full-field maps of swelling instead of a single average value of swelling as is the current industry practice. This feature is important because shale formations have complex mineralogy and their properties change at or below millimeter scales. The proposed device can also provide anisotropic values of shale swelling. This feature is important since shale behavior is usually different in the direction of lamination compared to perpendicular to lamination. The anisotropic and heterogenetic nature of shales are important considerations in the representation of complex shale behavior in contact with water.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
