FIELD APPLICATION OF ACIDIZING AND INJECTION INCREASE TECHNIQUE IN THE HIGH TEMPERATURE AND LOW PERMEABILITY WELLS OF JIDONG OILFIELD

It is difficult to utilize the conventional method to acidize the Gaoshangbao deep formations of Jidong oilfield because the burial depth of the reservoir is deep, the temperature is high, the heterogeneity among and in layers is serious and the content of mineral sensitive to acid is high. On the basis of indoor experiment, 2 wells have been acidized by means of the following process:flush the well before acidizing, remove the organic plugging by injecting organic plug removal agent, dissolve the carbonate cements by injecting the pad fluid, do not back flow the residual acid, inject water in time and so on. Certainly, the host acid is consisted of the retarded acid with the characteristics of high temperature resistance and low damage. At the same time, the sandstone acidizing real time monitoring system is used to monitor the operation quality. This series of matching techniques not only helps to attain to the aim of injection increase in water injection wells, but also helps to deepen the cognition to the physical property, connectivity, water intake capacity of separate zones, contamination degree of reservoir and so on of the target zone. The effect is obvious.