Research and Practice of Daqing Oilfield on Fine and Efficient Water Flooding Development at the Ultra High Water Cut Stage

Abstract Being developed with water flooding for more than 5 decades, the Daqing Oilfield is now in a developing period of ultra -high water cut. But the remaining oil still exists, and is in a status of highly scattered. As to the recognition and exploration of the remaining oil, the high-efficiency development strategy is promoted in this paper. The mechanism of improving development effect by fine waterflood adjustment is firstly studied by the using of numerical and physical methods, the practice and result of water flooding fine potential tapping are systematically discussed. Field application at the 6 pilots shows satisfactory performance for 3 years under the water cut of 92%. This offers a new way for the fine and efficient water flooding development of maturing oilfields at the ultrahigh water cut stage and valuable reference for water flooding development of multilayered sandstone oilfields. Introduction Daqing Placantieline Oilfield has entered into the "ultra-high water-cut and ultra-high recovery factor" development phase, with the recovery percent of recoverable reserves of 86.49% and the water cut of 92.75%. Waterflood development of Placantieline oilfield has faced many development problems, such as high water cut of all wells and layers and scattered distribution of remaining oil. The waterflood adjustment efficiency by macroscopic well pattern structures has become lower. The difficulty to control water cut and production decline by waterflood development has been becoming larger. Therefore, the current waterflood adjustment technology can not completely satisfy the need for fine waterflood adjustment at ultra-high water cut period[1,2]. In 2010, Daqing Oilfield launched 6 pilots for fine waterflood remaining oil tapping at ultra-high water cut period, lots of waterflooding technologies have been applied thoroughly. Meanwhile, by the application of fine reservoir description, fine injection-production system adjustment, fine injection-production management, each item of work involved in oilfield development and management has become more meticulous. Through all these efforts, production decline and water-cut increase have been prevented successfully for three years in these pilots.