高含水期油田提高原油采收率的新理论  

A new theory of improving oil recovery factor for oilfields in extra high water cut stage

作　　者：窦宏恩 

机构地区：[1]中油勘探开发研究院,北京100083

出　　处：《特种油气藏》2009年第6期89-93,共5页Special Oil & Gas Reservoirs

基　　金：国家科技重大专项"我国油气勘探开发理论成就与新一代勘探开发理论集成"(2008ZX05043-002)资金资助

摘　　要：研究了相对渗透率曲线、分流方程和Buckly-Leverett(贝克利-列维特)方程等在传统水驱提高采收率理论中的作用,从贝克利-列维特方程及物质平衡关系出发,从理论上推导出了水驱油效率及采收率计算公式。结合中国东部高含水/特高含水油田提高水驱采收率的实践,从理论上进一步分析了最终水驱油效率不是一个定值。研究表明:在油田开发过程中,随着水驱时间的延长,油田开发深度的不断加大,储层孔隙结构、孔渗参数和流体参数不仅随着油藏温度和压力变化,而且随着流体的不断采出,流体性质,尤其是粘度发生了较大的变化。通过初步理论分析,提出在油田开发过程中相对渗透率曲线是不连续的,相对渗透曲线上的2个端点值Kro和Krw在水驱油田开发中是变化的,残余油饱和度不是一个定值,且极限为零。由导出公式分析认为,不论采用何种驱替介质来驱扫储层中的原油,均可起到既提高驱油效率又扩大波及体积的双重作用。该理论的提出揭示了高含水油田进一步大幅度提高采收率的机理所在。研究认为,新理论是对传统水驱理论的挑战,还需要在理论上和试验研究中进一步证实。This paper examines the functions of relative permeability curve,fractional flow equation and Buckley-Leverett equation in the theory of improving oil recovery efficiency by conventional waterflood.Equations of waterflood efficiency and recovery factor are derived based on Buckley-Leverett equation and material balance relationship.It has been analyzed that the ultimate waterflood efficiency is not a constant value according to the practices of improving waterflood oil recovery for high water cut and extra high water cut oilfields in eastern China.The study shows that reservoir pore structure,porosity and permeability,and fluid parameters change with reservoir temperature and pressure at different stages of oilfield development.As the fluid is increasingly produced,the property of the fluid especially the viscosity will change a lot.It is proposed through theoretical analysis that the relative permeability curve is non-continuous during oilfield development process,the two end point values,Kro and Krw,change over time,and residual oil saturation is not a constant value and the limit is zero.This new theory is a challenge to traditional waterflood theory and needs to be further proved through theoretical and experimental studies.

关 键 词：高含水油田 提高采收率 驱油效率 相对渗透率 水驱新理论 

分 类 号：TE33[石油与天然气工程—油气田开发工程]