强非均质储层精细调整方法研究及应用

Research and Application of Fine Adjustment Method for Strong Heterogeneous Reservoir

随着油田滚动开发,聚驱区块的开发效果逐渐变差,为明确原因并提出调整措施,提高聚驱目的层的开发效益,开展研究。宏观上分析了近年来聚驱阶段采收率变化情况,微观上分析了储层K80方法筛选聚合物时存在的问题;分析了储层渗透性与不同聚合物的匹配情况,确定了强非均质储层在利用常规K80法筛选聚合物时应参考的边界界限。研究表明,对强非均质区块,常规K80法筛选的聚合物无法兼顾渗透率较大的油层,使聚驱阶段实际采收率大幅降低,统计结果显示实际采收率可低于预测值1%~2%。现场统计和岩心实验显示,渗透率大于0.3μm^(2)、0.2~0.3μm^(2)、0.1~0.2μm^(2)的储层分别在注入2500万、1900万、1200万相对分子质量的聚合物时提高采收率最高,说明其匹配性最好;对K80在非均质性强的储层应用效果,提出了对应的调控技术,制定了区块分质注聚图版。M区块实际开发效果表明通过分质注聚图版,调整强非质区块注入聚合物类型,可以提高采收率2%以上。

With the continuous development of oil fields,the development effect of polymer flooding blocks gradually deteriorates.In order to clarify the causes of this problem and put forward corresponding adjustment measures,the research was carried out to improve the development benefit of polymer flooding target layer.Macroscopically,the changes of recovery efficiency in polymer flooding stage in recent years were analyzed,and microscopically,the problems existed in screening polymer by reservoir K80 method were analyzed.The matching of reservoir permeability with different polymers was analyzed,and the boundary limits that should be referred to when screening polymers by the use of conventional K80 method for strongly heterogeneous reservoirs were determined.The results show that for highly heterogeneous blocks,the polymer screened by conventional K80 method can't take into account the reservoir with large permeability,which greatly reduces the actual recovery rate in the polymer-flooding stage.The statistical results show that the actual recovery rate can be lower than the predicted value of 1%~2%.Field statistics and core experiments show that reservoirs with permeability greater than 0.3μm^(2),0.2~0.3μm^(2) and 0.1~0.2μm^(2) have the highest enhanced recovery when injected with 25 million,19 million and 12 million polymer respectively,indicating the best matching.The application effect of K80 in highly heterogeneous reservoirs is analyzed,the corresponding control technology is put forward,and the block mass injection polygraph is formulated.This technology can be applied to fine adjustment of similar highly heterogeneous reservoirs,and also provides a prototype for the application of K80 method in the actual field.The actual development effect of M block proves that the recovery rate can be in-creased by more than 2%by means of mass dispersing polymerization plate and adjusting the type of polymer injected in strong non-material block.