大牛地气田大12-大66井区沉积微相与储层产能关系

以大牛地气田大12—大66井区为研究对象,基于物质供给和沉积水动力条件、河道结构与特征,探讨了沉积微相纵向结构与产能分布之间的成因关系,沉积微相横向结构与产能分布之间的内在关系。研究表明,物质供给和沉积水动力条件的组合关系是影响沉积微相纵向产能分布规律,其中物质供给充分、稳定的强水动力条件下,主要为中高产气层;分流河道微相中心位置,测试产能相对稳定,中高产气层分布比较多。分流河道微相边部,测试产能有不稳定的特点。两个强水动力沉积的河道交汇处,是中、高产气层的密集发育区。另外,曲流化的固定河道,因复杂化而形状变化大、难钻遇,但潜力大。不稳定河道,储层整体产能低,但强水动力沉积区仍具挖潜价值。研究结果与大12—大66井区生产测试结果吻合。

Relationship between sedimentary microfacies and reservoir productivity in Da12-Da66 wellblock,Daniudi gas field

Based on sediment supplies,sedimentary hydrodynamic conditions,channel structures and features,the paper discusses the relationship between the vertical/lateral structures of the sedimentary microfacies and reservoir productivity in Da12-Da66 wellblocks,Daniudi gas field.The result indicates that the combinations of source supplies and sedimentary hydrodynamic conditions affectes the vertical distribution of reservoir productivity.Under the condition of abundant sediment supplies,stable and strong hydrodynamic conditions,the formations are mostly payzones with medium to high productivity.Reservoirs in the central part of distributary channel microfacies have been commonly tested relatively stable productivity and are mostly payzones with medium to high productivity.In contrast,reservoirs at the edge of distributary channel have been usually tested with the feature of unstable productivity.The payzones with medium to high productivity grow usually in the intersection of two channels with strong hydrodynamic conditions.In addition,because of complexity of meander channel and great shape changes,it is difficulty to identify and discover.Generally,productivity is lower for unstable channel except for areas with strong hydrodynamic conditions.The study results coincide with the production tests in Da12-Da66 wellblocks.