| Abstract |
Understanding of the permeability of reservoir rocks at elevated temperature is becoming increasingly important both in oil field development and stimulation and in geothermal energy production. Rock properties such as permeability are often measured at ambient conditions with reservoir characteristics then based on these ambient measurements. liowever, rock and fluid properties may be radically altered at elevated temperatures due to the enhanced rates of mineral dissolution and growth and other geochemical processes. A number of previous experimental studies have focused on determining the permeability of sandstones at reservoir conditions: Aruna (1976) measured permeability using water, nitrogen, oil, and 2-octonol of quartz sandstones at reservoir conditions as a function of temperature. A strong reversible decrease in permeability was noted when water was used. Rock permeability to the other fluids showed essentially no change with temperature. These results were supported by similar experimental studies of Danesh and others (1978) and Gobran and others (1980). Experiments by Piwinski and Netherton (1977) have shown decreases in permeability during continuous flow of Salton Sea brines through sandstone cores at 90?C. Read (1980) has observed decreases in permeability during dissolution studies of sand packs and cores at temperatures to 260?C. The purpose of this study was to systematically investigate the effects of temperature and fluid composition on the permeability of quartz sandstones. We have concentrated our initial efforts on the time and flow dependence at 2 elevated temperatures (lOO?C, 200?C). |