冲积扇储层构型精细解剖方法——以克拉玛依油田六中区下克拉玛依组为例

An Accurate Anatomizing Method for Structure of Reservoir of Alluvial Fan:A Case Study on Lower Karamay Formation,Liuzhong Area,Karamay Oilfield

为了深化对冲积扇储层内部结构和剩余油分布的认识,为开发后期井网调整和剩余油挖潜提供更准确的地质依据,以克拉玛依油田六中区为例,应用岩心、露头、测井及动态等资料,以层次分析、模式拟合的研究思路,对研究区储层特征进行了深入分析,提出了一套冲积扇储层构型解剖方法。经研究认为,研究区为冲积扇体的一部分,建立了该区冲积扇沉积模式。将冲积扇划分为4个相带:扇根、扇中内缘、扇中外缘和扇缘-湿地。扇根和扇中内缘砂砾岩体以连片状为主;扇中外缘以宽条带状为主;扇缘-湿地以窄条带状为主。将单一砂砾岩体叠置方式分为垂向叠置、侧向交错、侧向叠置、侧向分隔及侧向拼接5种叠置方式。利用密闭取心井资料,对储层精细解剖结果进行了验证,指出剩余油富集场所。在构型界面附近,剩余油富集。

In order to recognize the internal structure of the alluvial fan reservoir and distribution of remaining oil and provide a more accurate geological basis for the well pattern adjustment and the remaining oil potentiality of production tail in oilfield, the Liuzhong area of Karamay oilfield, as a case, is studied. Using the method of scale analysis and model fitting, the data of coring, outcrop, logging and performance, reservoir characteristics of alluvial fan in studied area is well researched. A comprehensive analysis method for reservoir architecture of alluvial fan is proposed. The result shows that the study area belongs to a part of the alluvial fan. The depositional model of alluvial fan was established. It can be divided into four zones, fanhead, intra middle fan, outer middle fan and fan margin-wetlands. The distribution of composite glutenite is divided into three patterns： a sheet distribution pattern in fanhead and intra middle fan, a broad ribbon distribution pattern in outer middle fan and a narrow ribbon distribution pattern in fan margin-wetlands. The overlying manners of a single conglomerate body are listed as five types, vertical-overlay, lateral-interleaving, lateral-overlying, lateral-separating, lateral-stitching.The quantitative scale of a single conglomerate body was established. The result of detailed architecture was verified by pressure coring well. Authors point out that the remaining oil is enriched near the sand body boundary.