Profile Control And Flooding Development Program Design In Hainan No. 3 Block

Right now, most oilfields in our country have entered the high water-cut period. Influenced by various geology and development factors, the sweep efficiency and displacement efficiency injected water are low. As a result, the development effect of water-flooding decreased dramatically. The Hainan No. 3 block, which is studied in this article, locates in shallow sea and in a complex natural condition; the development level has reached level two. At present, some development problems emerged in the block. For example, water cut increases rapidly, utilization ratio of oil layer is low, swept volume of injected water is difficult to improve etc. However, the reservoir still possesses some quantity of remaining recoverable oil, the injection-production patterns are relatively complete, remaining oil are still partly concentrated. Therefore, it is necessary to take actions to solve the problems above, to exploit the remaining oil and to improve the recovery ratio.According to the acquaintance on geologic feature of Hainan No. 3 block and the analysis of development effect, this article researches on the development program design of Hainan No. 3 block on the basis of main problems existed in development. First of all, it analyzes the potential, distribution and the type of remaining oil through methods of dynamic analysis and numerical simulation. Then it analyzes the feasibility for profile control and flooding combination technology in Hainan No. 3 block and ensures Hainan No. 3 block has the feasibility. Though laboratory screening experiment and evaluation experiment, it chooses the volumetric expansion grain and gel system constituted by polymer P2 and cross linking agent NJ-5 together to plugging the forepart high permeability zone and effective path; phenolic gel system were used to control longitudinal injection profile; then optimized surfactants were used to continue follow-up displacement. According to the reservoir features of Hainan No. 3 block, this article chooses 3 well-groups of major block 15-15 to conduct the design of development program, and then it determined proper parameters of injection system, each development index and dynamic monitoring method. With numerical simulation to predict development index of the 3 well-groups, the result indicates that oil recovery could be improve by 1.9%, oil production could be increased by 2.5×10~4t, increased oil production in 10 years would be 1.461×10~4t.