Experimental Study on the Two-Phase Seepage Law of Tight Sandstone Reservoirs in Ordos Basin

The Jiyuan oil field is a tight sandstone reservoir, and water injection does not effectively enhance the oil recovery. The microscopic seepage characteristics of water flooding are studied through physical and streamline simulation experiments. The results indicate that the piston-type displacement efficiency varies between 60% and 80%, and the nonpiston-type displacement efficiency reaches approximately 40%. The length of the horizontal section imposes the greatest influence on reservoir production, followed by the fracture length and the number of fracture segments, whereas the fracture conductivity impacts reservoir production the least. When the horizontal section length is 1,500 m, and the fracture length is 1,100 m, 5 fracture segments and 10 horizontal well clusters are adopted, and the conductivity of the artificial fractures reaches 200 um(2) x cm, while the oil field production efficiency reaches its maximum value. The preceding research results were applied in the Jiyuan oil field, and the results reveal that the initial well production increased by 47.06%, the decline rate decreased by 9.96%, and the well output increased by 19.1% during the stable production period. This research yields a reference significance for the efficient development of similar reservoirs. (c) 2021 American Society of Civil Engineers.