塔里木盆地寒武系玉尔吐斯组优质烃源岩的发现及其基本特征

发布时间：2018-06-13 02:50

本文选题：优质烃源岩 + 寒武系　；参考：《天然气地球科学》2016年01期

【摘要】：塔里木盆地古生界海相油气资源丰富,已发现了塔河、哈拉哈塘、塔中等多个亿吨级的大型油气田,探明海相油气储量超过25×10~8t当量,并已建成年产海相油气超过1 400×10~4t当量产能,但是对主力烃源岩的认识,不同学者和勘探家们各持己见,寒武系还是奥陶系哪套是主力烃源岩一直存在争议。虽然诸多地球化学家做了大量卓有成效的工作,并有效指导了塔里木盆地油气勘探工作;但是由于盆地的复杂性和样品的限制,制约了一些研究工作的开展和精细对比,油气来源的观点未能得到勘探家们的充分认可和共识。通过对塔里木盆地寒武系野外详细踏勘和实验分析,在阿克苏地区10余个露头点发现了玉尔吐斯组优质烃源岩,岩性为黑色页岩,有机碳(TOC)值主要分布在2%~16%之间,特别是在于提希、什艾日克沟等剖面,黑色页岩层有机碳值高达4%~16%,是中国目前发现的有机碳值最高的海相烃源岩。这套优质烃源岩在阿克苏一带分布稳定,厚度在10~15m之间,主要形成于中缓坡至下缓坡沉积环境,有机质的富集受上升洋流控制。玉尔吐斯组之上的肖尔布拉克组发育厚层白云岩,野外露头未发现烃源岩,台内滩和微生物礁滩发育,储层较好;中寒武统发育厚层膏岩和泥岩,是一套良好的盖层;下寒武统玉尔吐斯组优质烃源岩与肖尔布拉克组微生物礁滩相储层和中寒武统膏泥岩盖层构成一套良好的生储盖组合,成藏条件优越,具有较大勘探潜力。
[Abstract]:The Paleozoic marine oil and gas resources in Tarim Basin are abundant, and many large oil and gas fields have been found in Tahe, Harahatang and Tazhong. The proven marine oil and gas reserves exceed 25 脳 10 ~ (8) t equivalent, and the annual production capacity of marine oil and gas is more than 1,400 脳 10 ~ (4) t. However, different scholars and prospectors hold different opinions on the main source rocks, and there is always controversy over whether Cambrian or Ordovician is the main source rock. Although many geochemists have done a lot of fruitful work and effectively guided the exploration of oil and gas in the Tarim Basin, due to the complexity of the basin and the limitation of samples, some research work and fine correlation have been restricted. The idea of the source of oil and gas has not been fully recognized and agreed by prospectors. Based on the detailed field exploration and experimental analysis of Cambrian in Tarim Basin, a high quality source rock of Yultusi formation has been found in more than 10 outcrops in Aksu area. The lithology of the source rock is black shale, and the value of organic carbon is mainly distributed in the range of 2% to 16%. In particular, the organic carbon values of the black shale beds are as high as 4 / 16 in the Tishi and Shizike gully sections, and are the highest organic carbon values found in marine source rocks in China at present. This set of high quality source rocks distributes stably in Aksu area and its thickness is between 10m and 15m, mainly formed in the sedimentary environment from moderate slope to lower slope, and the enrichment of organic matter is controlled by rising ocean current. The thick dolomite is developed in the Scholburak formation above the Yultux formation, and no source rock, platform beach and microbial reef beach are found in the outcrop in the field, and the reservoir is good, while the thick gypsum and mudstone are developed in the Mesozoic Cambrian, which is a good set of caprocks. The high quality hydrocarbon source rock of the lower Cambrian Yultusi formation, the microbial reef beach facies reservoir of the Scholburak formation and the middle Cambrian gypsum mudstone caprock constitute a set of good assemblages of source, reservoir and caprock. The reservoir forming conditions are superior and have great exploration potential.
【作者单位】：中国石油勘探开发研究院;
【基金】：中国石油天然气股份有限公司项目“塔里木盆地震旦—寒武系油气地质综合研究及接替领域优选和风险目标评价”(编号:2015-40213-01)资助
【分类号】：P618.13

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