塔里木盆地轮南地区 深层寒武系台缘带新认识及盐下勘探区带 ——基于岩石学、同位素对比及地震相的新证据

作    者：倪新锋 1,2，陈永权 3，王永生 1,2，熊 冉 1,2， 朱永峰 3，朱永进 1,2，张天付 1,2，俞 广 1,2，黄理力 1,2
单    位：1 中国石油杭州地质研究院； 2 中国石油集团碳酸盐岩储层重点实验室； 3 中国石油塔里木油田公司
基金项目：受国家科技重大专项“大型油气田及煤层气开发”等联合资助
摘    要：
塔里木盆地轮南地区轮探1井在8 000 m以深的下寒武统台缘带白云岩中获得重大突破，证实了寒武系台缘带发育优质生储盖组合，是塔里木盆地深层重要的油气勘探领域。通过岩石学、同位素地层对比及地震相分析，认为轮南地区寒武系台缘带经历了早期碳酸盐缓坡到中后期镶边台地的沉积演化过程，形成寒武系盐下多套优质生储盖组合：早寒武世玉尔吐斯期为富泥质的较深水中缓坡外带—外缓坡沉积，发育一套厚20~30 m的烃源岩；肖尔布拉克期为中缓坡外带石灰岩沉积，构造高部位局部发育潮坪及颗粒滩相白云岩储层；吾松格尔期，发育8~10 km宽的弱镶边台缘礁（丘）滩相储层；中寒武世发育4~5 km宽的强镶边台缘，台内发育5~8 km宽的膏云坪、泥云坪相泥质白云岩及10~15 km宽的膏盐湖—盐湖相膏盐岩2类优质盖层。指出轮南地区吾松格尔组弱镶边台缘及礁（丘）后颗粒滩与中寒武统膏盐岩构成的储盖组合是目前最现实的勘探领域；中寒武统沙依里克组盐间颗粒滩储盖组合值得进一步探索；古构造高部位肖尔布拉克组的上部白云岩地层仍具勘探潜力。
关键词：台缘带； 演化； 碳同位素； 勘探区带； 盐下； 寒武系； 塔里木盆地

Recognition of platform margin and subsalt exploration prospect of deep-buried Cambrian in Lunnan area of Tarim Basin, Northwest China: new understanding based on evidence of petrology, isotope comparison and seismic facies

Author's Name: NI Xinfeng, CHEN Yongquan, WANG Yongsheng, XIONG Ran, ZHU Yongfeng, ZHU Yongjin, ZHANG Tianfu, YU Guang, HUANG Lili
Institution: 
Abstract:
Well Luntan 1 in the Lunnan area of the Tarim Basin has made a major breakthrough in the dolomites of the Lower Cambrian platform margin zone at a depth of more than 8 000 m, which proves that the Cambrian platform margin zone has developed high-quality source-reservoir-cap assemblages and is an important oil and gas exploration field in the deep layers of the Tarim Basin. Based on petrology, isotope stratigraphic comparison and seismic facies analysis, it is believed that the Cambrian platform margin belt in Lunnan area has experienced the sedimentary evolution process from the early carbonate gentle slope to the middle-late rimmed platform, forming multiple sets of high quality Cambrian subsalt source-reservoir-caprock assemblage. The Lower Cambrian Yuertus Formation was developed in mud-rich middle gentle slope outer zone-outer gentle slope in relatively deep water, and a set source rock of 20-30 m was developed in the formation. The Lower Cambrian Xiaoerbulak Formation was developed in middle gentle slope outer zone with limes depositing on it, and tidal flats and granular shoal dolomite reservoirs developed locally in high structural positions. In the Wusonggeer period of Early Cambrian, 8-10 km wide mound-shoal reservoir was developed in weak-rimmed margin. During the Middle Cambrian, strong-rimmed platform margin with a width of 4-5 km was developed; 5-8 km wide argillaceous dolomite of gypsum dolomite flat-argillaceous dolomite flat facies and 10-15 km wide gypsum-salt rock of gypsum salt lake-salt lake facies were developed in platform interior, which formed two kinds of high quality cap rock. It is pointed out that the most realistic exploration field in the Lunnan area is the reservoir-cap assemblage of the granular shoal reservoir in weak-rimmed platform margin and behind the reef of Wusonggeer Formation and gypsum-salt cap rock of Middle Cambrian. It is worth exploring for the reservoir-cap assemblage of the inter-salt granular shoal in the Middle Cambrian Shayilik Formation. The dolomite strata in the upper part of the Xiaoerbulak Formation in the high part of the paleostructure still have exploration potential.
Keywords: platform margin; evolution; carbon isotope; exploration zone; subsalt; Cambrian; Tarim Basin
投稿时间： 2020-12-22  
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