摘要
以三塘湖盆地马朗凹陷二叠系芦草沟组为例,通过高分辨率岩心图像扫描、常规薄片、扫描电镜、能谱分析等岩石学研究方法,结合微量元素、生物标志化合物等地球化学指标,对湖相富有机质纹层状细粒岩的岩石学特征、沉积成因进行了研究,并分析了其页岩油气/致密油气勘探意义。研究结果表明,纹层具有硅质碎屑富集层、碳酸盐富集层、凝灰质富集层及有机质富集层4种类型,通过组合可以形成3种层偶类型。有机质呈纹层状富集或分散状分布于碳酸盐纹层及凝灰质纹层中。缺少陆源碎屑供给的封闭盐湖沉积体系,形成了分层的古湖泊水体,加之湖底的热水活动和季风性气候共同控制了有机质的富集保存及湖相多元纹层状细粒岩的形成。由于该类细粒岩有机质丰度高,具有较好的生烃潜力,碳酸盐纹层微孔及纹层间微裂缝发育,使其具有丰富的储集空间类型,且脆性矿物含量高而易于后期压裂改造,具备形成页岩油气/致密油气的有利条件,勘探意义重大。
Taking the Permian Lucaogou Formation in the Malang sag, Santanghu Basin as an example, by using petrological methods such as high resolution core image scanning, conventional thin section, scanning electron microscope and energy spectrum analysis and geochemical tests such as trace elements and biomarker compounds, the petrologic features and sedimentary origin of the lamellar organic rich fine-grained rocks of lake facies were investigated, and its significance for shale oil and tight oil exploration was analyzed. The results of the study show that there are four types of laminae, siliciclastic enrichment laminae, carbonate enrichment laminae, tuffaceous enrichment laminae and organic matter enrichment laminae, which can form three kinds of layer combinations. Organic matter is laminar enrichment or dispersed in the carbonate laminae and tuff laminae. Stratification of ancient lake water was formed in the closed saline lake sedimentary systems with insufficient continental clast supply, and the activity of warm water at the lake bottom and the monsoon climate worked jointly to control enrichment of organic matter and formation of lacustrine lamina fine-grained rocks. This kind of fine-grained rocks have higher potential of hydrocarbon generation due to high abundance of organic matter, are rich in reservoir space due to the existence of micro-pores in carbonate laminae and micro-cracks between the laminae, and suitable for fracturing because of high brittle mineral content. They have favorable conditions for shale oil and tight oil accumulation, and are significant for exploration.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2015年第5期598-607,共10页
Petroleum Exploration and Development
基金
国家自然科学基金"泥页岩脆塑性主控因素及定量评价研究"(41472125)
国家青年自然科学基金"湖相纹层泥页岩有机质富集机理及其与页岩油关系"(41202101)
黑龙江省青年自然科学基金"湖相富有机质细粒沉积体系页岩油富集机理与资源潜力"(QC2015043)
黑龙江省普通本科高等学校青年创新人才培养计划(UNPYSCT-2015077)
关键词
纹层状细粒岩
纹层组合
有机质富集方式
岩石学特征
成因模式
页岩油气
致密油气
lamellar fine-grained rock
laminae combination
organic matter enrichment mode
petrologic characteristics
genetic model shale oil and gas
tight oil and gas
