华蓥天池涧水沟剖面长兴组台内礁滩剖面精细地质研究

Fine Geological Study about Inner Platform Reef and Shoal Profile of Changxing Formation in Jianshuigou, Tianchi of Huaying

摘要: 礁滩相带是碳酸盐岩油气勘探的有利沉积相带，弄清台内礁滩相带的分布和演化规律，对川东地区台地内部油气勘探具有重要的意义。通过对广安华蓥天池涧水沟长兴生物礁进行剖面精细写实和详细研究，对其生物礁内部构成特征进行深入研究，精细刻画出礁滩内部构成和形成模式，指出礁体内部有利储层的分布规律。剖面上识别出三期生物礁生长旋回，均由粒屑滩沉积的礁基和障积礁或骨架礁组成的礁核构成，分别对应于三个向上变浅的准层序组，总体构成加积–进积型生物礁；其中第二期生物礁最为发育。各期生物礁生长旋回顶部的礁滩复合体白云石化强烈，有利于储层形成。

Abstract: Reefs and shoals are favorable sedimentary facies about carbonate rock oil and gas exploration. Cla-rifying the distribution and evolution of inner platform reef and shoal facies is important to oil and gas exploration in inner platform of eastern Sichuan. Through fine realistic and detailed study of Jianshuigou reef profile of Changxing Formation in Tianchi of Huaying, Guangan, this paper in depth researches the internal composition of reef, depicts the internal structure and the formation patterns of the reef, and points out the distribution of favorable reservoir inside the reef. Three growth cycles of reef have been identified, which is made up of reef base and reef core. The growth cycle of reef was consisted by reef base and reef core, among them grain shoal constitutes the reef base and skeleton reef or barrier reef constitutes the reef core. Three reef cycles were identified in the profile, which correspond to the three upward shallowing parasequence sets, and overall constitute accretion - into product type reef. The second reef cycle is the most developed. Complexes dolomitization is strong in the growth cycle phases of the top reef, and is good for the formation of reservoir.