Experimental Study on Reservoir Sensitivity for Chang 6 Reservoir in CD Block of Ordos Basin

The development of low-porosity and low-permeability oil and gas fields has been concerned by scholars all over the world. This study focuses on the sensitivity study of Chang 6 reservoir in CD block of Ordos Basin. Through analysis by such technological means as rock core fluid flow experiment, X diffraction, rock core slices, scanning electron microscopy, it is proven that Chang 6 reservoir mainly gives primary to acid sensitivity, the velocity sensitivity is in the next place and the alkaline sensitivity and water sensitivity are in the end. The sensitivity minerals mainly cover the chlorite, calcite, ferrocalcite, dolomite, siderite and other minerals. Through discussion about the relationship among porosity, permeability and sensitivity indexes, it is deemed that he relationship among porosity, permeability and sensitivity indexes is closely related, and it is found through discussion for four kinds of sensitivity indexes that the trends of velocity sensitivity and acid sensitivity index curves are consistent, and the trends of alkali sensitivity and water sensitivity index curves are consistent. The consistency on relationship possibly enables that relationship between alkali sensitivity and water sensitivity are closely related to the fluid mineralization and the velocity sensitivity and acid sensitivity are closely related to the reaction rate of fluid.