【摘要】 渤海辽东湾海域辽西低凸起锦州20-2气田古近系沙河街组沙二上亚段储层具有岩性杂、埋藏深、总体厚度薄及横向变化大的特点,因而储层分布成为制约气田开发调整的重要因素。从岩心和薄片观察入手,以岩石学特征分析为基础,根据已钻井测井曲线的形态特征、岩相组合进行了沉积微相和沉积环境分析,识别并划分出了生物滩、碳酸盐局限台地、碎屑滩和深湖4种沉积微相;应用地震层位拉平技术恢复了研究区目的层沉积时的地貌;以单井相划分为主要依据,结合沉积环境分析和古地貌恢复的认识,通过井-震结合,分析了沙二上亚段微相平面展布。研究认为:锦州20-2气田古近系沙河街组沙二上亚段沉积微相平面上明显受古地形控制,为湖泊孤岛型台地沉积;储层岩性有碳酸盐岩、砂岩和混积岩,相对而言,生物碎屑碳酸盐岩的储层物性最好并且厚度大;储层发育和分布受沉积微相控制。更多还原

【Abstract】 The reservoir of the upper of the second member of Paleogene Shahejie Formation in Jinzhou 20-2 Gas Field in Liaoxi low uplift has the characteristics of complex lithologies, deep buried depth, thin thickness and great lateral variations. The reservoir distribution is an important restriction factor for the development adjustment of the gas field. Based on petrography, this paper studied sedimentary microfacies and environment from the data of core observation and thin section identification, together with the well logging curve morphological feature and lithofacies assemblage pattern, and recognized four kinds of microfacies including organic bank, carbonate restricted platform, clastic bank and deep lake. Sedimentation landform of target formation in the study area was restored by application of seismic horizon flattening technique. Based on the division result of single well facies, the plane microfacies distribution of the upper of the second member of Shahejie Formation was analyzed combined with analysis of sedimentary environment and understanding of ancient landform restoration. It is suggested that sedimentary microfacies of the upper of the second member of Paleogene Shahejie Formation in Jinzhou 20-2 Gas Field is lake-island type sedimentation, and it is obviously controlled by ancient terrain. The reservoir lithology consists of carbonate rock, sandstone and peperite. Thus, relatively speaking, bioclastic carbonate is with the best reservoir properties and thick layer. Reservoir development and distribution are controlled by sedimentary microfacies.更多还原