Study On Oil Injection Scheme For Ultra - Deep Volatile Reservoir In Lunnan Oilfield

The JIII6+7reservoir of Block2in Lun Nan oilfield is a volatile oil reservoir with a small condensate gas cap with buried depth4504meters. Because of the poor formation properties, inadequate natural formation energy, and complex fluid quality, the JⅢ6+7reservoir was not developed well in the last20years with oil recovery only13.89%. So it is necessary to adjust the reservoir development strategies. This paper focused on enhancing the oil recovery plan study of hydrocarbon injection for JⅢ6+7reservoir, which came from the major technical study of CNPC "The exploration and production stabilization technique study of clastic reservoir" and aimed to improve the development effects and enhance the oil recovery greatly of the reservoir. Based on the fine reservoir description study, this paper completes several specific studies which include the redefining the reservoir type, development evaluation, numerical simulation study, mechanism study of gas injection development etc. The study results showed:The JⅢ6+7is a volatile oil reservoir with a small condensate gas cap; The main contradiction of the reservoir is imperfect well pattern、short of formation energy supplement and oil well production declined quickly because of reservoir degassing; It can reach miscible flooding with hydrocarbon injection on the formation pressure condition. Also the gas and water alternate injection from top and water injection from base plan was proposed, which can reach19%increment on oil recovery. This development plan is the first miscible hydrocarbon injection plan in Tarim Oilfield and its implement will provide great experience for other oil fields in Tarim Oilfield in enhancing oil recovery course.