Chang 8 ultra low permeable reservoir stress sensitivity lab experiment in Zhenjing oilfield

Zhengjing oilfield Chang 8 reservoir in south of Ordos basin is ultra low permeability lithologic reservoir, experiments have been carried out based on ministry standard and modified factorial design experiment. The experimental results show that the permeability changes a lot with the effective stress. Experimental data derived from modified factorial design show that when higher inner pressure is large, permeability change greatly with confining pressure. Three methods are evaluated based onstress sensitivity evaluation. For modified factorial design experiment scheme, sensitivity is weak by using the stress sensitivity coefficient method. This method is more consistent with the actual production process, therefore has more reference value.