Book Description

Organic-rich shales in the last decade have become a focus of the oil and gas industry, and currently are the primary source of oil and gas production from Unconventional resources. These resources will be in need of a method of enhanced recovery to maximize lifetime production from each well. Spontaneous imbibition, or the adsorption of a fluid into a porous media due to capillary forces and consequent displacement of non-wetting fluids is a good potential enhanced recovery method. Measuring the amount of spontaneous imbibition in an organic-rich shale is complicated by several challenges compared to traditional oil reservoir rocks, such as the ultra-low permeability and the high clay content. This clay content can often lead to swelling, which can affect imbibition measurements. In this study, a new gravimetric method for measuring spontaneous imbibition is developed that can measure the rate, and volume of spontaneous imbibition as well as the degree of shale swelling. Two organic-rich shales, the Bakken and the Utica were examined and compared to establish the viability of the experimental method. The results of this work suggest that this method is a promising and viable method for measuring the volume and rate of spontaneous imbibition in organic-rich shale. The exposure of organic-rich shales to atmospheric conditions can significantly modify the properties of the shale through drying or hydration of the samples. All of the shales used in experiments in the following study were carefully maintained at their native state before exposure to the imbibition fluids. Additionally, the shale samples were exposed to several surfactant mixtures to measure the effect of these surfactants on the rate of imbibition.