While much progress has been made in developing fraccing technology and methods, the permeability of gas shale 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 fracs. More often than not, transport of gas from matrix to fracs is so slow that production is not economic.
To improve productivity, it is necessary to find ways of better connecting the fine (nano-micro) scale porosity that characterizes 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 fracs.
The present project will investigate whether the stress-strain- sorption behaviour and mechanical damage characteristics of gas shales can be employed, alongside fraccing, 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 likely have similar effects in shales.