Experimental Study on Stress Sensitivity of Low Permeability Glutenite Reservoir in Wushi Sag

In order to clarify the change law of rock stress sensitivity during the development of Wushi low permeability glutenite reservoir, taking WS17-2-9 well block of WS17-2 Oil field as an example, different physical core samples were selected to carry out stress sensitivity experiments under constant overburden pressure. Firstly, the effective stress range was designed according to the current standard, the overburden pressure of the reservoir and the saturation pressure of crude oil. Then the rock permeability of reducing and increasing internal pressure with different effective stresses was tested respectively. Finally, the rock stress sensitive damage degree under experiment initial effective stress and reservoir initial effective stress is quantitatively evaluated. The results show that with the increase of effective stress, rock permeability decreases sharply at first and then slowly; the damage of stress sensitivity to rock permeability is irreversible, and the worse the rock physical properties are, the more serious the damage is. In addition, the stress sensitivity under reservoir conditions is far less than the experimental results of current standards. As long as the formation energy is supplemented in time during the development of Wushi low permeability glutenite reservoir, the adverse effects of stress sensitivity can be neglected.