Enhancing shale gas production by promoting pore connectivity between shale matrix and fracs
Publieke samenvatting / Public summary
While much progress has been made in developing fracking technology and methods, the permeability of the shale gas matrix material is so low that very close frac spacing is often needed to achieve sufficiently rapid transport of gas from the shale matrix into the induced frac. More often than not, the transport of gas from matrix to frac is so slow that production is uneconomic.
To improve productivity, it is necessary to find ways of better connecting the fine-scale (nano-micro) porosity that characterises shale matrix material, so that transport to either natural or induced fracs is accelerated. In other words, it is necessary to find ways of promoting pore connectivity within the shale matrix, hence promoting transport from matrix to frac.
The present project will investigate whether the stress-strain-sorption behaviour and mechanical damage characteristics of gas shales can be employed, alongside fracking, to achieve the desired increase in matrix permeability. Recent experiments have shown that coupled shrinkage-desorption-damage processes can substantially increase the permeability of coal, and will likely have similar effects in shales.