摘要: The long-range goals of this research are (1) to measure experimentally the magnitudes of the fluxes of water, dissolved substances, heat and electric current across smectite and illite clay layers, under imposed gradients of flui... 展开 The long-range goals of this research are (1) to measure experimentally the magnitudes of the fluxes of water, dissolved substances, heat and electric current across smectite and illite clay layers, under imposed gradients of fluid pressure, chemical activity of dissolved salts, temperatures, and electrical potential, from atmospheric conditions through the diagenetic range to approximately 250 C and 2 kb confining (lithostatic) pressure, and (2) to relate these measurements to existing theories. Two 300-ton capacity load frames were constructed for monitoring the cited fluxes across constructed clay cakes of known mineralogy, fabric, and particle-size range. One of the load frames is enclosed in an air bath for operation to 250 C and precipitation-hardenable stainless steel and Ni-base alloy were used extensively in both for corrosion resistance to concentrated salt solutions and for strength at temperature. Novel design elements include a mechanism for driving upstream brine back and forth between two high pressure reservoirs to minimize salt buildup at the brine-clay cake interface, and a downstream sampling cell that allows fluid to be collected at a selected pressure. Thus, lithostatic pressure, hydrostatic pressure, and hydrostatic pressure gradient across the clay cake may be varied independently. At room temperature, a hydraulic differential of 1000 psi across clay cakes 1.5 to 2.5 cm thick and 9.15 cm in diameter held under 5,000 psi confining pressure gives approximately 1.0 ml fluid flow per day. Salt rejection efficiency is 26% for one molal (Na,Ca)Cl solution, and effluent Ca/Na ratio increases by 24%, but salt rejection efficiency for a 5.5 molal solution of the same Na/Ca ratio is only 8.4%. 收起