轮西缝洞型碳酸盐岩油藏注水替油工艺

Study on Water Injection to Replace the Oil in Lunxi Fracture-cavity Carbonate Rock Reservoir

轮西油藏为典型的缝洞型碳酸盐岩油藏。其储层特点、渗流模式与常规油藏不同,用常规注水方式来稳定地层压力和水驱油来提高采收率的方法难以奏效。为提高该类油藏的采收率,在分析轮西油藏缝洞单元内的油水关系及油井含水变化规律基础上提出单井注水替油工艺,给出了优选注水替油井、确定最佳注水时机及注水量的决策方法,并提出几点建议,为高效开发轮西油藏提供一种新方法。该工艺在LX10-H1井的实践结果表明：与未实施该工艺前相比较,油井关井时间由150天左右有效缩短至50~60天,而日产油量明显增加。

LunXi oilfield is a typical fracture-cavity carbonate reservoir.The characteristics of the reservoir and seepage flowing mode differ from the conventional reservoir.It＇s difficult to take effect to stabilize formation pressure through conventional water injection and to enhance oil recovery through water flooding.In order to enhance oil recovery of such reservoir,we present the technology of water injection to replace the oil in a single well,and discuss how to optimize the choice of injection wells,to determine the optimal time of water injection and optimal injection volume on the basis of the analysis of the relationship of water and oil,and water changing-law in Lunxi oilfield and propose some suggestions,which offers a new method for efficient development of Lunxi oilfield.Practical results of the craft used in LX10-H1 shows that：compared with period when the craft wasn＇t used,closed-in time of the well descends to 50~ 60days from about 150days and daily oil production increases obviously.