Shale reservoirs have very low permeability, causing wells to exhibit long periods of transient flow before the reservoir boundaries are reached and boundary-dominated flow occurs. Forecasting methods for shales must factor in such transitions in flow.
Well production forecasting comes down to four major classes — empirical, analytical, numerical and hybrid. Each has its pros and cons when it comes to forecasting production in unconventional reservoirs, says Chris Clarkson, professor and AITF Shell/Encana chair in unconventional gas and light oil research for the University of Calgary’s Department of Geosciences in Canada.
