摘要
川中地区下侏罗统自流井组大安寨段湖相页岩非均质性强,有利岩性组合的研究对目标层段的选取较为关键.通过对21口井的岩心观察与描述、有机质含量与主微量元素测定等,划分了岩性段及组合类型,并探讨了各组合类型特征.结果表明:大二亚段页岩层系主要发育泥质介壳灰岩、灰黑色页岩、含介壳页岩3类岩性,针对其生物介壳发育的特征,识别出特殊的介壳层岩性段;进一步总结出4类岩性段类型,A块状介壳灰岩段、B页岩与介壳层互层段、C页岩夹介壳层段、D纯页岩段.4类岩性段的古环境特征差异反映了不同的页岩油潜力,半潮湿-潮湿的古气候、较高的古生产力、合适的沉积速率,以及缺氧还原、半咸水-淡水环境有利于有机质的富集与保存,由此综合优选出有利岩性段类型为C页岩夹介壳层段,D纯页岩段次之.
The lacustrine shale in the Da’anzhai Member of Ziliujing Formation of Lower Jurassic in Central Sichuan has strong heterogeneity, and the study of favorable lithological combinations is critical to the selection of the target interval. Through the observation and description of cores of more than 21 wells, the determination of organic matter contents and major and trace elements, it classifies lithological combinations and discusses the characteristics of each type. The results show that the shale strata of Da2 sub-member mainly developed three types of lithology: muddy shell limestone, gray-black shale, and shell-bearing shale.Then, according to the characteristics of its biological shell development, the special shell-rich layer was identified. Furthermore,it summarizes 4 types of lithological sections: A massive shell limestone section, B shale and shell-rich layer interbedded section,C shale intercalated shell-rich layer section, D pure shale section. The differences in paleoenvironmental characteristics of the 4 lithological sections types reflect different shale oil potentials. Therefore, comprehensive analysis indicates that from semi-humid to humid paleoclimate, high paleoproductivity, suitable deposition rate, as well as anoxic reduction, brackish-freshwater environment are conducive to the enrichment and preservation of organic matter. Finally, the favorable lithology section types as C shale intercalated shell-rich layer section were comprehensively optimized, followed by D pure shale section.
作者
雷文智
陈冬霞
张芮
刘子驿
张少敏
Lei Wenzhi;Chen Dongxia;Zhang Rui;Liu Ziyi;Zhang Shaomin(College of Geosciences,China University of Petroleum,Beijing 102249,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;Exploration and Development Institute,PetroChina Southwest Oil and Gas Field Company,Chengdu 610400,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2021年第10期3657-3672,共16页
Earth Science
基金
国家科技重大专项(No.2016ZX05034001-005)。
关键词
陆相页岩
页岩油
大安寨段
含介壳页岩
页岩岩性组合类型
沉积环境
油气
continental shale
shale oil
Da’anzhai Member
shell-bearing shale
shale lithology combination type
sedimentary environment
hydrocarbon
