川东北地区飞仙关组层序-岩相古地理特征和鲕滩预测  

Characteristics of Sequence-based Lithofacies and Paleogeography,and Prediction of Oolitic Shoal of the Feixianguan Formation in the Northeastern Sichuan

作　　者：郑荣才[1] 罗平[2] 文其兵[3] 徐发波[3] 李瑜[3] 耿威[1] 

机构地区：[1]成都理工大学“油气藏地质及开发工程”国家重点实验室,成都610059 [2]中国石油勘探开发研究院油气储层重点实验室,北京100083 [3]中国石油西南油气田分公司重庆气矿,重庆400021

出　　处：《沉积学报》2009年第1期1-8,共8页Acta Sedimentologica Sinica

摘　　要：以沉积相和界面识别为依据,将川东北地区下三叠统飞仙关组划分为2个三级层序和6个体系域,在此基础上对飞仙关组层序地层学特征进行了分析,编制了各沉积体系域的层序—岩相古地理图和对鲕滩发育规律进行预测。结果表明:SQ1层序发育期,飞仙关组受持续海侵影响,形成以深水台盆为中心的台盆—台地边缘—开阔—局限—蒸发台地的相带展布格局,以海侵体系域的台地边缘和台内鲕滩最为发育,该体系域也是飞仙关组鲕滩相储层最发育的层位;SQ2层序发育期,受海平面大幅度下降和水循环受限及干旱炎热气候影响,区域沉积格局由开阔台地转化为局限台地,鲕滩逐渐消失,最终进入频繁暴露的蒸发台地环境,以沉积膏云岩为主,为飞仙关组天然气藏极其重要的第一套区域性致密盖层发育层位。The Feixianguan Formation of Lower Triassic in the northeast Sichuan can be divided into 2 third-order sequences, six system tracts in terms of sedimentary facies and sequence interfaces. Characteristics of sequence stratigraphy of the Feixianguan Formation are analyzed, sequence-palaeogeography maps compiled and development regularity of oolitic shoal predicted. It is indicated that, during the development of SQ1 sequence, the effect of transgression brings about such distribution framework of facies zones as platform basin-platform margin-open-limited-evaporate platform. Of the system tracts, the platform margin and oolitic shoal are the most developed ones. The effeets of large scale descent of sea level and dry and hot climate during the development stage of SQ2 translates the original open platform into limited one and eventually into evaporate platform with dominant deposition of dolomite, forming the first important regional tight caprock of the Feixianguan Formation which is favorable for the accumulation of oil and gas.

关 键 词：川东北 下三叠统飞仙关组 层序地层 岩相古地理 鲕滩 

分 类 号：P512.2[天文地球—地质学] P539.2