Practice and Exploration of High-Efficiency Waterflooding Development Technology for Medium and High Permeability Oil Reservoirs

In the face of the challenge of the deteriorating overall development benefits of waterflooding oil reservoirs during the high water cut period in Shengli Oilfield efforts are made from two aspects of cost reduction and efficiency improvement. Firstly according to the characteristics of different oil reservoirs a long-life layered water injection process technology with the core of fine separate injection for integrated rhythm layers separate injection with large pressure differences in fault blocks and small-diameter separate injection for casing damage repair wells has been formed. After implementation the total frequency of operations has decreased by 0.05 well times per (well * year). Calculated the workload has been reduced by 1768 well times and the operation cost has been reduced by 480 million yuan. Secondly an intelligent separate injection technology has been developed through research which is used to guide the matching and optimization of injection and production parameters and improve the efficiency of injection-production coupling and linkage. A total of 132 well times have been implemented. The qualification rate of layers has reached 89.5% the maximum daily oil increment of a well group has reached 3.8 tons per day and the cumulative oil increment has reached 9020 tons. Thirdly unstable water injection measures have been explored to expand the swept volume and further improve the development effect of waterflooding. Active explorations have been carried out from alternate water injection in oil reservoirs to pulsed water injection in well groups. The pulsed water injection test well group has an average daily oil increment of 2.1 tons and the cumulative oil increment is approximately 604.7 tons.