摘要
鄂尔多斯盆地东南部上古生界烃源岩主要为深色泥质岩、煤和碳酸盐岩,为1套陆相、海相及海陆过渡相沉积的含煤碎屑岩沉积,主要集中在二叠系山2—本溪组,具有广覆式的分布特征,受沉积相控制较大。煤系烃源岩是天然气最主要的供应者,第二位是暗色泥岩,其次为灰岩。泥质烃源岩的TOC平均含量大于2.25%,属于中—好烃源岩;碳酸盐岩的TOC平均为1.69%,属于好的烃源岩。干酪根镜检和稳定碳同位素研究显示,上古生界煤系地层中有机组分主要为镜质组,δ13C值为-26.23‰～-21.23‰,干酪根类型主要为Ⅲ型及少量Ⅱ型,总体上为腐殖型-腐泥型,源岩母质输入类型多样,以陆源高等植物为主。Ro值普遍大于2%,处于高—过成熟演化阶段,表明该区在盆地内为产气较多的地区。天然气运移通道和优势运移方向有效组合的研究,确定出该区的有利勘探区为宜君—黄龙一线以北的上古生界三角洲分流河道砂体带。
The Upper Palaeozoic hydrocarbon source rocks in the southeast of Ordos Basin are mainly composed of dark shale rocks,coal and carbonate rocks.The source rocks are a set of coal clastic sedimentary deposition of continental,marine and transitional facies and are mainly concentrated in the Benxi Formation of Permian,which have wide distribution features largely controlled by sedimentary facies.The coal hydrocarbon source rock is the main supplier of natural gas,the second is dark mudstone and the third is limestone.The average content of TOC in shale hydrocarbon source rocks is higher than 2.25%,which belongs to medium-good hydrocarbon source rocks.The average content ofTOC in carbonate is about 1.69%,which belongs to good hydrocarbon source rocks.The kerogen microscopic observation and stable carbon isotopic study show that the organic component of the Upper Palaeozoic coal stratum is mainly vitrinite with δ13C value being between-26.23‰ and-21.23‰ and the kerogen is mainly type III with a small number of type Ⅱ,which in general is humus type-sapropelic type and the input types of source rock materials vary,which are mainly higher plants.The Ro is commonly greater than 2%,being in a high-to-surpassing mature evolution stage,which shows that this area in the basin is a region that can produce more.The effective combination study of natural gas migration channel and dominant migration direction shows that the favorable exploration area is distributary channel sand body region of Upper Paleozoic delta in the north of the trend of Yijun to Huanglong.
出处
《特种油气藏》
CAS
CSCD
北大核心
2012年第5期21-25,151-152,共5页
Special Oil & Gas Reservoirs
基金
中油长庆油田公司2010年科技攻关项目"超低渗透油藏勘探理论与技术研究"(2010-99)
关键词
上古生界
烃源岩
有机地球化学
有利勘探区预测
鄂尔多斯盆地
Upper Palaeozoic
hydrocarbon source rock
organic geochemistry
play/favorable exploration area prediction
Ordos Basin
