四川盆地涪陵气田白马向斜五峰组—龙马溪组页岩气成藏地质条件及成藏模式  

Geological conditions and accumulation patterns of shale gas accumulation in WufengLongmaxi formations of Baima Syncline,Fuling Gas Field,Sichuan Basin

作　　者：万云强[1] 陈践发[2,3] 陈聪 刘超[1] 马勇 梁佳宝[2,3] WAN Yunqiang;CHEN Jianfa;CHEN Cong;LIU Chao;MA Yong;LIANG Jiabao(Research Institute of Exploration and Development,SINOPEC Jianghan Oilfield Company,Wuhan 430223,China;College of Geosciences,China University of Petroleum,Beijing 102249,China;National Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum,Beijing 102249,China)

机构地区：[1]中国石化江汉油田分公司勘探开发研究院,湖北武汉430223 [2]中国石油大学(北京)地球科学学院,北京102249 [3]油气资源与工程全国重点实验室(中国石油大学(北京)),北京102249

出　　处：《天然气地球科学》2024年第9期1656-1670,共15页Natural Gas Geoscience

基　　金：国家自然科学基金项目(编号:41802149,42173030);国家重点研发计划项目(编号:2021YFA0719000)联合资助。

摘　　要：目前国内页岩气勘探突破主要集中于中浅层超压页岩气藏,随着研究的深入,页岩气勘探逐步向深层过渡,四川盆地涪陵页岩气田白马向斜整体为深层超压气藏,勘探潜力较大。利用J148-1井五峰组—龙马溪组测井资料及测试分析数据,分析五峰组—龙马溪组页岩含气性特征及其影响因素,探讨页岩气形成富集机理及页岩气成藏模式。五峰组—龙马溪组页岩含气量介于1.09~6.81 m^(3)/t之间(平均为3.15 m^(3)/t),随埋深增大而增加,1~3小层平均含气量为5.35 m^(3)/t,为页岩气有利层段。总有机碳含量、矿物组成、储层性质及保存条件均对页岩含气性有一定控制作用,五峰组—龙马溪组页岩TOC值介于1.29%~5.50%之间(平均为2.75%),随埋深的增大而增加;石英含量为17.2%~64.7%(平均为36.1%),长石含量为2.7%~14.5%(平均为8.0%),碳酸盐矿物含量为2.0%~56.6%(平均为12.6%),黄铁矿含量为1.4%~6.7%(平均为3.4%),黏土矿物含量为17.2%~54.3%(平均为40.1%);1~4小层孔隙度介于2.38%~5.64%之间(平均为4.06%),8~9小层孔隙度介于1.95%~2.75%之间(平均为2.24%);1~4小层渗透率介于(0.03~16.43)×10^(-3)μm^(2)之间(平均为0.75×10^(-3)μm^(2)),8~9小层渗透率介于(0.05~55.63)×10^(-3)μm^(2)之间(平均为2.31×10^(-3)μm^(2)),总有机碳含量、石英含量、孔隙度等与含气量呈正相关关系;页岩发育矿物基质孔隙、有机质孔隙及裂缝孔隙3种孔隙类型,以有机质孔隙为主,研究区远离主控断层,区域性盖层发育,顶、底板岩性致密,保存条件好,游离气大量富集,为宽缓向斜型成藏模式。研究区五峰组—龙马溪组页岩在奥陶纪末—晚志留世处于未成熟阶段,晚志留世进入成熟阶段,中侏罗世进入高成熟阶段,晚侏罗世进入过成熟阶段,中白垩世热演化停止。At present,the breakthrough of shale gas exploration in China is mainly concentrated in the medium and shallow overpressured shale gas reservoir.With the deepening of research,shale gas exploration gradually goes to the deep layer.The Baima block of Fuling shale gas field is a deep overpressured gas reservoir with great exploration potential.Based on the well logging data and test analysis data of Wufeng-Longmaxi formations in well J148-1,the gas bearing characteristics and influencing factors of Wufeng-Longmaxi formations are analyzed in this paper,and the formation and enrichment mechanism of shale gas and the accumulation model of shale gas are discussed.The shale gas content of Wufeng-Longmaxi formations ranges from 1.09 to 6.81 m^(3)/t(with an average of 3.15 m^(3)/t),and increases with increasing depth.The average gas content of small formations 1-3 is 5.35 m^(3)/t,which is a favorable shale gas interval.The total organic matter content,mineral composition,reservoir properties and preservation conditions all have a certain control effect on the gas content of the shale.TOC of the Wufeng-Longmaxi formations is between 1.29%and 5.50%(with an average of 2.75%),and increases with the increase of burial depth.Quartz content is 17.2%-64.7%(average 36.1%),feldspar content is 2.7%-14.5%(average 8.0%),carbonate mineral content is 2.0%-56.6%(average 12.6%),pyrite content is 1.4%-6.7%(average 3.4%).The clay mineral content is 17.2%-54.3%(average 40.1%).The porosity of 14 layers is between 2.38%and 5.64%(average 4.06%),the porosity of 8-9 layers is between 1.95%and 2.75%(average 2.24%),and the permeability of 1-4 layers is between 0.03×10^(-3)and 16.43×10^(-3)μm^(2)(average 0.75×10^(-3)μm^(2)).The permeability of 8-9 small layer ranges from 0.05×10^(-3)to 55.63×10^(-3)μm^(2)(the average is 2.31×10^(-3)μm^(2)),and the total organic matter content,brittle mineral content and porosity are positively correlated with the gas content.There are three types of pores in the shale:inorganic pores,organic pores and micr

关 键 词：页岩气 五峰组—龙马溪组 含气性 白马向斜 成藏模式 

分 类 号：TE121.11[石油与天然气工程—油气勘探]