四川仪陇—平昌地区长兴组-飞仙关组层序地层及沉积演化  

Sequence stratigraphy and sedimentary evolution of Changxing—Feixianguan Formations in Yilong—Pingchang area,Sichuan Province

作　　者：廖鑫羽 肖云鹏 宋振宇 LIAO Xinyu;XIAO Yunpeng;SONG Zhenyu(CNOOC Energy Company Limited,Engineering Technology Hainan Compang,Chengmai 571999,Hainan,China;CNOOC China Limited,Hai Nan Branch,Haikou 570300,Hainan,China;Geosciences School of Yangtze University,Wuhan 430100,Hubei,China)

机构地区：[1]中海油能源发展股份有限公司工程技术海南分公司,海南澄迈571999 [2]中海石油(中国)有限公司海南分公司,海南海口570300 [3]长江大学地球科学学院,湖北武汉430100

出　　处：《地质通报》2024年第2期350-362,共13页Geological Bulletin of China

基　　金：大庆油田有限责任公司勘探开发研究院项目《仪陇—平昌地区海相碳酸盐岩岩相古地理研究》(编号:DQYT-1201002-2019-JS-1022)。

摘　　要：四川仪陇—平昌地区,特别是环开江-梁平海槽区域的长兴组—飞仙关组蕴藏着大量油气资源,但其三级层序划分方案有待统一。基于最新的钻井岩心、测井、野外露头资料综合分析,识别出岩性岩相突变界面及局部暴露不整合界面2种Ⅱ型层序界面,将仪陇—平昌地区的长兴组-飞仙关组划分为4个三级层序,建立了层序地层格架。该区目的层主要发育典型的镶边台地沉积体系,至晚期海槽消失,发育陆表海型台地体系开阔台地及蒸发台地。长兴组沉积期,开江-梁平海槽范围逐渐扩大,高位域是生物礁发育的有利阶段,由于SQ2晚期海平面急速下降,其生物礁规模较SQ1时期有所减小;飞仙关组沉积早期海平面快速上升,鲕粒滩难以形成,随后进入整体海退阶段,至SQ3高位域时期,鲕粒滩连片发育。层序划分方案与礁、滩储层发育特征匹配,能够应用于下一步油气勘探。The Yilong—Pingchang area in Sichuan,especially the Changxing—Feixianguan Formations in the region surrounding the Kaijiang-Liangping trough,contains a large amount of oil and gas resources,but the third class sequence classification scheme needs to be unified.Based on the comprehensive analysis of the latest drilling core,well logging,and field outcrop data,two types of type II sequence interfaces,including the lithologic facies abrupt interface and the partial exposure unconformity interface,were identified.The Changxing—Feixianguan Formations in the study area were divided into 4 third class sequences,and a sequence stratigraphic framework was established.The target stratum in the study area mainly developed a typical rimmed platform sedimentary system.In the late stage,the trough disappeared,and the open platform and evaporate platform of the epicontinental sea platform system developed.During the deposition of the Changxing Formation,the Kaijiang-Liangping trough gradually expanded,and the highstand system tract was a favorable stage for the development of reefs.Due to the rapid decline in sea level in the late SQ2 period,the scope of the reefs was reduced compared to the SQ1 period.The sea level rose rapidly in the early depositional stage of the Feixianguan Formation,and it was difficult to form oolitic shoals,and then entered the overall regression stage,and to the highstand system tract of SQ3,the oolitic shoals developed contiguously.The sequence classification scheme matches the development characteristics of reef and shoal reservoirs and can be applied to the next step of oil and gas exploration.

关 键 词：长兴组 飞仙关组 层序划分 沉积演化 仪陇—平昌地区 四川 

分 类 号：P512.2[天文地球—地质学]