复合砂体构型理论及其生产应用

近年来中海油提出并形成了复合砂体构型理论，在这一理论指导下取得了一系列重大发现。系统介绍了复合砂体构型理论提出的背景、基本概念、主要内容、表征方法和实践应用，探讨了复合砂体构型理论的意义。运用探地雷达证实了常见的构型单元往往是点坝复合体，当达到地震可分辨尺度时，一般对应于单一河道带或复合河道带，相当于小层或砂层组级别，这个级次的砂体定义为“复合砂体”，在油田开发中作为一个独立开发单元。复合砂体是由于河谷盆地构造变化从而造成可容空间和物源供给之间突变而引起的，地貌学上的阶地地貌证明了沉积作用和复合砂体构型样式之间的关系。论述了复合砂体构型界面、构型单元、构型模式、规模特征以及控制因素，明确了构型界面的现代沉积地貌标志。如何进行精细复合砂体构型表征关系到能否正确描述剩余油分布和量化开发指标，进而完善注采井网、提高加密调整井的成功率。

Theory of composite sand body architecture and its application to oilfield development

In recent years, the theory of composite sandbody architecture proposed by CNOOC has contributed to several major oil and gas discoveries.This paper systematically introduces the context for proposing this theory, its fundamental concept, main content and characterization method as well as practical application, and discusses the significances of this theory.Ground penetrating radar reveals that the common architecture element of modern and ancient meandering river deposits is point bar composite instead of a single point bar.When their scales being larger than seismic resolution, they commonly correspond to a single channel belt or composite channel belts and represent a sub-layer or sand group.A sand body of this kind is defined as a composite sand body and is treated as a separate development unit.The composite sand body is originated from abrupt change in accommodation and source supply caused by tectonic uplift or subsidence of basin valley.The relationship between depositional process and composite sand body architecture pattern is revealed by river terrace geomorphology.This paper illustrates architecture unit, architecture bounding surfaces, architecture model, scale characteristics and their controlling factors, and defines modern sedimentary geomorphic markers of architecture bounding surfaces.Fine characterization of composite sand body architecture is the key to precisely describing remaining oil distribution and quantifying development index, and further optimizing injection-production pattern and increasing success rate of infilling drilling.