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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。
The Paleozoic marine oil and gas resources in the Tarim Basin are rich in oil and gas resources. Many large-scale billion-ton oil and gas fields such as Tahe, Halahatang and Tazhong have been discovered. Proven marine oil and gas reserves exceed 25 × 10 ~ 8t equivalent and have been completed Annual production of marine oil and gas more than 1 400 × 10 ~ 4t equivalent capacity, but the understanding of the main source rocks, different scholars and explorers have their own opinions, Cambrian or Ordovician set is the main source rock has always existed dispute. Although many geochemists have done a great deal of fruitful work and have effectively instructed 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 has been restricted and finely contrasted, and the viewpoint of oil and gas sources failed Get full recognition and consensus of explorers. Based on a detailed exploration and experimental analysis of the Cambrian field in the Tarim Basin, Yutuasu excellent source rock was found in more than 10 outcrops of Aksu with lithology of black shale. The TOC values were mainly distributed in the 2% ~ 16%. Especially in the sections of Tiki and Shi’i Rigou, the organic carbon value of black shale is as high as 4% ~ 16%. It is the highest marine carbon source rock with the highest organic carbon found in China . This high-quality source rock is stable in the Aksu area, with a thickness of 10-15 m. It is mainly formed in the medium-gentle slope to the gentle slope depositional environment, and the enrichment of organic matter is controlled by the rising ocean current. Thick-layer dolomite is developed in the Shoballak Formation above the Yurtusi Formation. No source rock, inland beach and microbial reef beach are found in the outcrops of the Yü Tuusi Formation, and the reservoir is well developed. The Middle Cambrian developed thick- And mudstone, is a good cover; the Lower Cambrian Yultetu high-quality source rock and the Shorbuluke Formation microbial reef-shoal facies reservoir and the Middle Cambrian gypsum mudstone cover form a good reservoir Cap combination, favorable conditions for accumulation, with greater exploration potential.