绥中油田各项措施增油效果劈分方法

Splitting method of incremental oil effect by composite measures in Suizhong oilfield

绥中油田为海上重质稠油油田,地面原油密度为0.958~0.982 g/cm^3,地层原油粘度为50~250 m Pa·s。为了缓解注入水突进、改善区块开发效果和提高采收率,2003年在油田进行聚合物驱试验;2010年在注聚合物高含水井区实施整体提液措施,2013年开始进行细分层系试验开发。随着各项增产措施的交叉实施,难以确定每项措施的增油效果。利用类比法对聚合物驱增产效果进行评价,采用相对渗透率曲线和物质平衡原理推导出新型含水率预测模型,通过对比预测含水率曲线与实际含水率曲线,确定曲线的拐点即为各项措施的见效时间,曲线的差值即为各项措施的增油量。通过动态法和数值模拟法分别计算各项措施的累积增油量,实现对聚合物驱、整体提液、细分层系等措施增油效果的劈分。研究结果表明,截至2015年底,绥中油田聚合物驱、整体提液和细分层系的措施累积增油量分别为264.3×10~4,97.1×10~4和12.6×10~4m^3。

Suizhong oilfield is an offshore heavy oil one. The ground density of crude oil is between 0.958 and 0.982 g/cm^3.The underground viscosity of crude oil is between 50 and 250 m Pa·s. In order to decrease water breakthrough,to enhance oil recovery and to improve development effect,polymer flooding pilot test was put into practice in 2003. Enhanced liquid treatment was implemented fully in high water cut block in 2010,and subdivision of layer series was put into practice in2013. With the implementation of various measures,it is difficult to distinguish incremental oil effect of each measure.Analogy method was used to evaluate polymer flooding effect. The new water cut forecasting model was derived based on relative permeability curve and material balance theory. By comparing the predicted water cut curve with the actual water cut curve,the turning point of the curve is response time,and the difference value of the curve is oil increment of polymer flooding. Incremental oil of various measures was calculated by dynamic method and numerical simulation method,which realizes the splitting of incremental oil from polymer flooding,integral liquid increase,subdivision of series of strata and other stimulation measures. By the end of 2015,the cumulative incremental oil of polymer flooding is 264.3×104m^3,that of integral liquid increase is 97.1×104m^3,and that of subdivision of series of strata is 12.6×104m^3.