Stratified Water Injection Technology of Concentric Seal-Check, Logging and Adjustment Integration in Changqing Oilfield

In order to improve the test efficiency and to reduce the operation intensity and test cost of stratified water injection technology with small water volume in directional wells of Changqing Oilfield, the stratified water injection technology and key tools of concentric seal-check, logging and adjustment integration were studied. Mechatronics control method was adopted and the downhole test instrument was controlled by cable to carry out the seal-check, logging and adjustment. According to the principle of mechanical clutch structure, existing electric seal-check device was integrated with concentric electric measuring and adjusting instrument, the proposed technology further improved the degree of integration and automation with the functions of early seal-check device and measuring and adjusting instrument. The technology has been applied to more than 430 wells in Changqing Oilfield with one-trip operation completing the whole process of seal-check, measurement and adjustment. The success rate of logging and adjustment was up to 98.0%, and the logging and adjustment error of single layer was less than 10%. The average test duration of single well seal-check has been reduced from 6-8 hours to 4 hours, and the annual operation cost of single well was reduced by 9,600 yuan. The successful development of the stratified water injection technology of concentric seal-check, logging and adjustment integration could provide a new and high-efficiency test method for developing low permeability reservoirs in a cost-saving way.