The Effects of Qijia Oilfield Water Sensitivity to Formation Scaling of Injected Water

The Qijia oilfield is a low permeability reservoir, and it is difficult to inject water. For improving the water injection capability of Qijia oilfield, the experiments of water sensitivity and scaling evaluation are developed, and so on. But these experiments are the evaluation about single element. The actual situation of reservoir is not reflected accurately by this way. For determining the main element of water injection difficulty in Qijia oilfield, the experiment of core scaling after water sensitivity is carried on. It is known that the damage ratio to the permeability of core scaling after water sensitivity is more than the simplex scaling through comparing this experiment to the simplex scaling experiment. The reason is that the sloughed clay granule is existed in core after water sensitivity, and the new crystal nucleus is provided for scaling crystal. At the same, the inside wall of core porous channel is becoming coarse, the contact area is increased with the fluid, and it is instrumental for the adhesion and deposition of scale.