中古2井区良里塔格组礁滩体发育特征

Development characteristics of reef flat in Lianglitage Formation in Well Block Zhonggu 2

刘 凤 王振宇 孙崇浩 李新生 吉云刚 赵宽志

中国石化西南油气分公司工程技术研究院，四川  德阳 618000 西南石油大学资源与环境学院，四川  成都 610500 塔里木油田分公司, 新疆  库尔勒 841000

塔中I号坡折带中古2井区在晚奥陶世良里塔格组沉积时期，处于碳酸盐台地的边缘相带，发育粒屑滩，灰泥丘、礁丘及滩间海等亚相。研究表明，灰泥丘沿台地边缘成线、成带发育，在丘主体的内侧主要是砂屑滩相的分布区，组合形态上主要发育丘滩复合体、中低能砂屑滩体。中古2井区有利储层发育段主要集中在良二段，纵向上良一段—良四段共发育4套储层，横向上分布稳定，中间夹有薄层透镜状的非储层，自西向东，即从中古2井到塔中54井、塔中826井方向，储层逐渐变好，储层厚度逐渐增厚。

Well Block Zhonggu 2 of Tazhong I slope break zone is located in the margin facies tract of carbonate platform during sedimentation period of Lianglitage Formation, Upper Ordovician. Some subfacies developed there, including the grain banks, lime mud mound, reef knoll and interbank sea. The study results show that the lime mud mound developed along the platform margin in the form of line and zone and that the distribution of psammitic bank facies was mainly inside the hilllock, with the hillock-bank complex and low-to-moderate energy psammitic bank developed in the array configurations. The favorable reservoir sections are
concentrated mainly in Liang II section in the well block. There are four suits of favorable reservoir from Liang Ⅰto Liang Ⅳsections vertically, with the distribution being stable laterally. The thin lenticular nonreservoirs are among the reservoirs. From west to east, i.e. along the direction from Well Zhonggu 2 to Well Tazhong 54 and Well Tazhong 826, the reservoirs are getting more favorable and the reservoir thickness is extended gradually