Heavy Oil Development Technology of Liaohe Oilfield Han Yun(Scientific Research Information Department Exploration&Development Research Institute，Liaohe Oilfield Company)Liaohe Oilfield，the largest heavy oil production base in China，features in various reservoir types，deep burial，and wide range of crude oil viscosity．For many years，a series of technologies have been developed for different oil products and reservoir types of the oilfield，of which water flooding，foam slug drive，steam stimulation，steam drive,and SAGD are the main technologies. After continuous improvement，they have been further developed and played an important role in the development of heavy oil in the oilfield．Liaohe Oilfield is abundant in heavy oil resources，46％of the total proved reserves of Liaohe Oilfield Company. Horizontally the resources concentrates in the West Depression and the southern plunging belt of the Central Uplift in Liaohe Rift. Vertically,it is mainly distributed in Paleocene Shahejie Formation(ES). The distinctive geological feature of Liaohe 0ilfield is manifested in three aspects：first，the heavy oil reservoirs are deeply buried and 80％of them are buried more than 900m deep；second，the heavy oil viscosity ranges widely．For most of the reservoirs．the dead oil viscosity ranges in 100～100000mPa·s with the maximum 650000mPa·s.Third the reservoir types are various with complicated oil—water relationship，most of the reservoirs are edge water and bosom water reservoirs and there are also edge water reservoirs，top water reservoirs and bosom water reservoirs．For more than 20 years of development，Liaohe Oilfield has developed series of heavy oil development technologies for different oil products and different types of reservoirs，such as water flooding, foam slug drive,steam stimulation steam drive and SAGD．The most difficult issues have been overcome in the development of the superheavy oil in deeper formation．which has maintained the annual heavy oil output at 8 million tons for many years in Liaohe Oilfield．Water flooding development technology for conventional heavy oil-type 1Based on heavy oil classification,the conventional heavy oil．type I refers to the heavy oil with viscosity ranging in 50～100mPa·s，taking up about 20％of the proved oil reserves of the oilfield．The heavy oil reservoirs of this type are buried ranging from 1 500m to 2400m deep and are capable of flowing．Therefore，natural energy is utilized for conventional development and then water flooding technology is used．For example，the reservoir of $32 oil unit of Block Leng-43 is buried 1 650～l 940m deep with the average oil zone 87.7m thick and the oil viscosity in situ 58mPa·s．In 1992，the 141 m spacing square well pattern was adopted to develop the kind of reservoirs by utilizing natural energy and two sets of oil production zones．In 2004，water flooding technology was applied. Currently,the degree of reserve recovery reaches 14％．the annual oil recovery rate is 1％，and the ultimate recovery ratio is predicted to be as high as 22％．Technology of foam slug and for conventional heavy oil-type steam flooding for conventional heavy oil-type 2 The upper limit of viscosity for the conventional heavy oil—type II is l 0000mPa·s(the dead oil viscosity in situ)．This kind of heavy oil is the dominant type of heavy oil in Liaohe Oilfield，accounting for 60％of total proved reserves．The reservoir of such heavy oil is buffed 800-1 600m deep in genera1. At initial development stage, steam stimulation was carried out to develop this kind of reservoirs．In the higher cycles of steam flooding，the reservoirs with the heavy oil viscosity close to the lower limit of this kind of heavy oil are conversed into the steam drive development．Pilot tests of foam slug and steam flooding have conducted inBlock Jin-90 and Block Qi-40 successfully,and they will be applied to the whole blocks in near future．The recovery factor is forecast to be up to 50％~60％．Steam stimulation technology for special heavy oilThe special heavy oil refers to the heavy oil with the viscosity ranging in 10000~50000mPa·s in situ,which takes up 10% of proved oil reserves of the oilfield. The reservoir of the kind of oil is buried ranging from 1400m to 1800m. Steam simulation technology is often applied to develop such reservoirs. However, technology of steam drive or SAGD are also under research and experiments for reservoirs of good quality.SAGD technology for super heavy oilThe super heavy oil reservoir refers to the heavy oil with dead oil viscosity in situ over 50000mPa·s, which accounts for 10% of proved reserves of the oilfield. Due to its extremely high viscosity, it is just developed for few years. For the massive super heavy oil reservoirs, SAGD can be applied in the late stage of steam stimulation. At present, good intermediate results have been obtained in SAGD pilot test in Block Du-84 of Guantao Formation, showing good prospect for application. They have been applied in the whole block and the ultimate recovery factor is predicted to achieve 55%.ConclusionVarious technology should be applied to develop different types of heavy oil reservoirs. Besides the technologies mentioned above, the technologies of combustion in situ, flue gas drive, and steam foam drive are also under research currently. Therefore, various development technologies will be increasingly improved with the heavy oil development of Liaohe Oilfield.References[1] Wang Xu. 2006. Heavy Oil Development Technologies and Discussion on the ResearchOrientation in the Next Step. Petroleum Exploration and Development [J],33(4):484~490[2] Liu Junrong. The Paper Collection of Liaohe Oilfield Development Seminar [C]:Beijing, Petroleum Industry Press, 2002[3] Zeng Yuqiang. 2006. Heavy Oil steam Stimulation Review. Special Oil&Gas Reservoir[J], 13(6):5~9辽河油田的重油开发技术韩云（科研信息部门勘探和开发研究所、辽河油田公司）辽河油田，在中国最大的重油生产基地，在不同的储层类型，具有埋藏深，与原油粘度范围宽。