延长油田西部油区长6油藏递减规律分析

Analysis of Decline Law of C6 Reservoir in the West of Yanchang Oilfield

将延长油田西部区块单井月产曲线归一化,分段拟合后发现长6油井在投产第一年内快速递减,递减形式为指数递减;此后递减变缓,递减形式为调和递减。借鉴前人研究成果,明确影响区块递减率相关因素。应用灰色关联分析法,对宏观参数对区块递减率的影响进行分析。结果表明,对递减率影响大小依次为生产时间>井网密度>含水率>生产压差>阶段注采比,并指出实施精细注水、控制生产时率、治理关停井等是减缓长6油藏递减的主要方法。

Normalizing the monthly production curve of a single well in the western block of the Yanchang Oilfield andfitting it in segments,it was found that the Chang-6 oil well rapidly decreased in thefirst year of production,with a decreasing form of exponential decline;Afterwards,the decrease slows down and takes the form of harmonic decrease.Drawing on previous researchfindings,clarify the factors related to block decline rate.Apply grey correlation analysis method to analyze the impact of macro parameters on block decline rate.The results show that the impact on the decline rate is in the order of production time>well density>water content>production pressure difference>stage injection production ratio.It is pointed out that implementingfine water injection,controlling production time rate,and treating shut down wells are the main methods to slow down the decline of the Chang 6 oil reservoir.