A Method to Measure the Relative Brine Release Capacity of Geologic Material

A method to estimate the brine released by pumping a brine-saturated geologic unit has been developed. This method addresses the need of those evaluating mineral-rich brine-saturated deposits for a rapid screening test that is suitable for multiple samples and textures and that avoids issues associated with brine as the pore fluid. The method involves applying a vacuum to a group of saturated samples in a parallel configuration. The parallel configuration allows rapid analysis of up to 10 samples simultaneously. The amount of brine produced in response to the vacuum, referred to as the “relative brine release capacity” (RBRC), provides a basis for comparison of the amount of brine produced from different samples. The RBRC is related to the specific yield of a material, which is principally a function of material texture. In this study the method was first applied to sand, clay, and sandstone samples saturated with tap water so that the results could be compared to water retention data developed from standard methods. The results were consistent with the water retention data as well as with the range of published specific yield values for these textures. Subsequent measurements on several hundred brine-saturated samples produced RBRC values in an expected range consistent with the texture of the samples.