摘要
滦页1井压裂试产成功地开采出工业性页岩油气,使滦平盆地中生代白垩系西瓜园组成为该地区目前勘探研究的重点层位。近期的对滦页1井的岩石学研究表明,生油层发现有细粒火山物质沉积,并与页岩油气生成和聚集存在紧密关系。因而探明火山细粒物质与页岩油气形成的关系成为新的命题。以滦平盆地西瓜园组下段为研究层位,结合岩心、薄片、测井、X衍射和地化测试数据等资料,对含凝灰质细粒沉积岩的沉积特征和有机质发育情况进行分析,旨在为该地区页岩油气的进一步勘探开发提供理论支持。西瓜园组下段受火山-湖泊作用控制,发育湖相泥页岩、受火山活动影响的含凝灰质细粒沉积岩、火山相的安山岩以及火山碎屑岩等。结果显示,泥页岩的平均总有机碳含量(TOC)为0.64%,平均S_(1)+S_(2)含量为0.41 mg/g;含凝灰质细粒沉积岩的平均TOC为1.92%,平均S_(1)+S_(2)含量为2.64 mg/g。含凝灰质细粒沉积岩层位有机质含量明显更富集。细粒火山物质发育的层段中大量发育草莓状黄铁矿,同时Pr/Ph较小,V/(V+Ni)偏大也指示了火山喷发后强还原的水体环境,及火山细粒物质沉积后快速埋藏都有利于有机质的保存。湖相碳酸盐岩发育,与纹层状富有机质泥岩、凝灰岩交互,层间裂缝利于油气的运移,凝灰岩纹层和白云岩纹层提供了储集空间。页岩油气具有源-储一体的特点,细粒火山物质的存在从有机质的富集和成烃演化到油气的储集、保存条件都产生了积极的作用。
Industrial shale oil/gas flow was successfully tested in Well Luanye 1 after fracturing,and the Cretaceous Xiguayuan Formation in the Luanping Basin has currently been a key zone of hydrocarbon exploration and research in this area.Recent petrological studies on Well Luanye 1 show that fine-grained volcanic materials have been discovered in the source rocks and are closely related to the generation and accumulation of shale oil/gas.It has become a new proposition to explore the relationship between fine-grained volcanic materials and shale oil/gas.The lower member of Xiguayuan Formation in the Luanping Basin is the target of the study with a combination of analyses and laboratory data such as cores,microscopic thin sections observation,logging,X-ray diffraction and geochemical test.The sedimentary characteristics and organic matter development of the fine-grained tuffaceous sedimentary rocks are discussed to provide theoretical support for further exploration and development of shale oil/gas in the area.On the other hand,the development of lower member of Xiguayuan Formation is controlled by volcano-lacustrine interaction,with lacustrine shale,fine-grained tuffaceous sedimentary rocks under the effect of volcanic activities,as well as andesite and pyroclastic rocks of volcanic facies well developed within.The results show that in the shale,the average TOC content is 0.64%,and the average S_(1)+S_(2) content is 0.41 mg/g;in the fine-grained tuffaceous sedimentary rocks,the average TOC content is 1.92%,and the average S_(1)+S_(2) content is 2.64 mg/g,indicating that the abundance of organic matters is markedly greater in the fine-grained tuffaceous sedimentary rocks.Pyrite framboids are widely developed in the intervals where fine-grained volcanic materials are enriched;meanwhile,Pr/Ph is smaller and V/(V+Ni)is larger,also indicating a strong reduction of water environment after volcanic eruption.The rapid deposition and burial of finegrained volcanic materials is conducive to the preservation of organic matters.Lacustrine carbonate rocks are well developed and interbedded with laminated organic-rich mudstone and tuff.The interlayer fractures are conducive to hydrocarbon migration,while the tuff and dolomite laminae provide reservoir spaces.The fine-grained volcanic materials play a positive role in the complete process from the enrichment and hydrocarbon generation of organic matters to the storage and preservation of oil/gas.
作者
刘晓宁
姜在兴
袁晓冬
陈晨
王成
Liu Xiaoning;Jiang Zaixing;Yuan Xiaodong;Chen Chen;Wang Cheng(School of Energy Resources,China University of Geosciences(Beijing),Beijing 100083,China)
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
2022年第2期390-406,共17页
Oil & Gas Geology
基金
国家自然科学基金面上项目(41772090)。
关键词
细粒火山物质
岩石类型
页岩油气
西瓜园组
白垩系
滦平盆地
fine-grained volcanic material
rock type
shale oil/gas
Xiguayuan Formation
Cretaceous
Luanping Basin
