四川盆地中三叠统雷口坡组岩相古地理与规模储集体特征  

Sedimentary characteristics and sequence lithofacies paleogeography of the semi-closed carbonate platform of the Leikoupo Formation in Sichuan Basin

作　　者：杨威[1] 刘满仓[1] 魏国齐[1] 金惠[1] 谢武仁[1] 武赛军[1] 苏楠 朱秋影[1] 郝翠果[1] 王小丹 YANG Wei;LIU Man-cang;WEI Guo-qi;JIN Hui;XIE Wu-ren;WU Sai-jun;SU Nan;ZHU Qiu-ying;HAO Cui-guo;WANG Xiao-dan(Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China)

机构地区：[1]中国石油勘探开发研究院,北京100083

出　　处：《天然气地球科学》2021年第6期781-793,共13页Natural Gas Geoscience

基　　金：国家科技重大专项“大型油气田及煤层气开发”(编号:2016ZX05007-002)资助。

摘　　要：四川盆地中三叠统雷口坡组近年取得重要的勘探发现,规模储集体是控制成藏的关键因素之一。通过野外露头、探井、测井和地震等资料,编制雷口坡组岩相古地理图,分析规模储集体特征,得到3点新认识:(1)雷口坡期四川盆地南、东、北3个方向较封闭、海水从西侧进入,为较封闭碳酸盐岩台地;雷一、二段沉积期为弱镶边碳酸盐岩台地,雷三、四段沉积期为镶边碳酸盐岩台地。(2)雷口坡组发育台地边缘、开阔台地、局限台地和蒸发台地等沉积相,以局限台地相为主,包括潟湖、台内滩和潮坪等亚相,发育台地边缘滩和台内滩2类油气储集体。(3)雷口坡组发育2套规模颗粒滩储集体:一是川西北地区雷三、四段台地边缘滩,厚度大(一般大于50 m);二是川中地区雷一段下部的台内滩,厚度小、分布稳定、面积大(大于20 000 km2)、成规模,这2类规模储集体经多期岩溶作用改造,形成质量较好的储层,为规模油气成藏提供物质基础。In recent years,important exploration findings have been made in the Middle Triassic Leikoupo Formation in Sichuan Basin,and the large-scale reservoir is one of the key factors to control the hydrocarbon accumulation.Based on the data of outcrops,exploration wells,logging and seismic data,the lithofacies paleogeographic map of Leikoupo Formation is compiled and the characteristics of large-scale reservoirs are analyzed,and the following three understandings are obtained.(1)In Leikoupo stage,Sichuan Basin was a relatively closed carbonate platform,the south,east and north directions of Sichuan Basin were relatively closed,and seawater entered from the west.The first and second members of Leikoupo Formation are weakly rimmed carbonate platform,and the third and fourth members of Leikoupo Formation are rimmed carbonate platform.(2)The Leikoupo Formation can be divided into platform margin,open platform,restricted platform and evaporate platform,and the restricted platform is the main one,including lagoon,intra-platform shoal and tidal flat.There are two types of hydrocarbon reservoirs in Leikoupo Formation:Platform margin shoal and intra-platform shoal.(3)The Leikoupo Formation develops two sets of large-scale mound shoal reservoirs.One is the platform margin mound shoal of the third and fourth members of Leikoupo Formation in Northwest Sichuan,with large thickness(generally more than 50 m).And the other is the intra-platform shoal in the lower part of the first member of Leikoupo Formation in Central Sichuan,which has the characteristics of small thickness,stable distribution,large area(more than 20000 km2)and large scale.These two types of large-scale reservoirs are reformed by multi-stage karstification to form good quality reservoirs,which provide material basis for large-scale hydrocarbon accumulation.The results of this paper improve the understanding of the deposits and reservoirs of Leikoupo Formation in Sichuan Basin,and guide the hydrocarbon exploration in this field,which has important theoretical and pra

关 键 词：封闭台地 四川盆地 雷口坡组 岩相古地理 规模储集体 油气勘探 

分 类 号：TE122.2[石油与天然气工程—油气勘探]