大宛齐油田薄互层油藏提高采收率对策研究

大宛齐油田属于复杂断块油藏,纵向多套油层发育,含油砂体面积小且厚度薄,注采井距仅为50~70m,油田开发过程中采用多层合采和合注的方式,层间矛盾突出。基于大量的产液剖面、吸水剖面等资料对井区层间矛盾进行系统分析,同时建立油藏数学模型,采用正交实验设计方法对含油单砂体采收率的主控因素和层间矛盾进行了系统研究,明确砂体规模、水体大小是影响砂体采收率的关键因素,基于研究成果对井区提出了砂体分类、分级动用、对应精细注水等开发调整对策并取得了良好的应用效果,对井区的下步调整和同类油田开发具有一定的指导意义。

EOR Strategies of Thin Interbedded Reservoirs in Dawanqi Oilfield

The Dawanqi oilfield is a complex faulted oil reservoir with multi-sets of payzones vertically developed. The oil-bearing sands have a small area, and thin thickness, with only 50-70 m of injection-production well spacing. Multilayer commingled production and injection are applied to the oilfield development process, resulting in significant conflicts between layers. The interlayer contradictions of the well block are systematically analyzed on the basis of using a great many production fluid profiles, water injection profiles and other data. Meanwhile a mathematical model of reservoir is established. The main controlling factors of the recovery efficiency of individual oil-bearing sand body and interlayer contradictions are systematically studied by using the orthogonal experiment design method. The scale of the sand bodies and size of the water bodies are ascertained to be key factors to have influence on recovery efficiency of the sand bodies. Development adjustment countermeasures such as classification of the sand bodies, producing reserves by grading, corresponding precise water-flooding and the like, are proposed for the well blocks based on the research achievements, and with good results of application.