小集油田注水开发前后储层参数变化特征研究

Pore structure parameters variation character studying before and after water injection in Xiaoji oil field

（1.中国石油化工股份有限公司石油勘探开发研究院,北京100083；2.中国石油大学（北京）,北京102249）

Exploration & Production Research Institute,SINOPEC,Beijing 100083,China

老油田注水后,储层的孔隙结构参数会发生明显变化,研究这种孔隙结构参数变化的规律,可为合理开采剩余油提供依据。分析了小集油田取心井水淹前和水淹后孔隙度和渗透率的变化特征,按不同韵律沉积储层总结出3种孔隙结构参数变化类型,即以复合韵律为主的变化类型、以正韵律为主的变化类型和与反韵律、复合韵律关系密切的变化类型。研究了注水后胶结物对储层孔隙结构的影响和注入水冲刷作用对孔隙度和渗透率的影响,讨论了其发生变化的原因。基于上述分析研究结果,结合剩余油合理开采的思想,认为以反韵律和复合韵律为主的孔隙结构参数变化类型处于较低含水期,是油气挖潜的主要对象。将孔隙结构参数变化特征与注采后产液剖面和吸水剖面相结合,有助于制定出与剩余油相关的最佳注采调整方案。

After flood development,oil field has obvious variation on pore structure parameters,which can be used to guide remaining oil exploitation by studying the variation characteristics of pore structure parameters.Comparing the porosity and permeability before and after water injection in Xiaoji oilfield,three variation types of pore structure parameters is distinguished,including composite rhythms,positive rhythm,composite rhythm and reverse rhythm.The impact of cement on reservoir pore structure after water injection and the impact of flushing action of the injected water on porosity and permeability were studies,and the reasons were discussed.Based on the above study results,combined with the idea of remaining oil exploration,we think that the variation type of pore parameter mainly of reverse rhythms and composite rhythms is in a relative low water cut stage,it is the target for hydrocarbon potential tapping.It is helpful to establish the best injection-production adjusting plan for promoting remaining oil recovery efficiency by combining variation characteristics of pore structure parameters with production profile and injection profile after water injection.