Room 1670 Beyster Building
Effect of Surfactant Adsorption on Shale Wettability, Water Imbibition and Natural Gas Production
It is known from industrial experience that the majority of the hydraulic fracturing treatment water used to stimulate gas production in shale reservoirs is lost to the shale and does not return to the surface. Water imbibition in low permeability reservoirs usually results in reduced reservoir gas production, however, shale gas production has been demonstrated to be positively correlated with the amount of water imbibed by the shale. It is predicted that the different surfactants in the hydraulic fracturing fluid dictate the water/shale interaction and by extension, the reservoir productivity, although the detailed adsorption behavior in these complex fluids is poorly understood. Here we use contact angle & surface tension measurements to study the change in wettability of Marcellus shale due to interaction with commonly used surfactants in hydraulic fracturing completion fluids. We further investigate the effect of these surfactants on the rate of water imbibition in shale fractures through use of neutron imaging techniques.