西藏羌塘盆地天然气水合物气源研究
发布时间：2019-01-27 20:45
【摘要】：随着我国国民经济的快速发展,能源问题越发受到关注。天然气水合物作为一种新型能源,主要赋存于海底沉积物和陆地永久冻土带中,以其巨大的储量,有望成为未来石油、天然气重要的接替能源。羌塘盆地是我国公认的陆域天然气水合物成矿条件和找矿前景最好的地区,但至今尚未获得天然气水合物存在的直接证据。近几年的调查研究表明,气源条件成为制约羌塘盆地天然气水合物找矿突破的关键因素。 本文以羌塘盆地天然气水合物钻探试验井所获取的岩芯样品为研究对象,通过系统的有机地球化学分析,对多组烃源岩进行了评价,进而探讨了羌塘盆地天然气水合物成矿气源条件和成矿潜力。烃源岩评价结果显示,(1)上三叠统土门格拉组碎屑岩中发育一套深灰色-灰黑色为主的泥岩,有机质丰度较高,有机质类型主要为Ⅲ型,热演化程度较高；(2)下侏罗统曲色组泥岩、油页岩有机质丰度普遍较高,以Ⅱ2型干酪根为主,较利于油气的生成,但其热演化程度处于成熟阶段,尚未达到生成天然气阶段；(3)中侏罗统布曲组灰岩有机质以Ⅱ2型干酪根为主,产油气潜能中等,且其热演化程度较高,已进入生气阶段,但布曲组灰岩有机质丰度总体不高,仅局部可达到烃源岩下限；(4)中侏罗统夏里组以中等-差烃源岩为主,有机质多为Ⅲ型,其热演化程度也较高,达到了高-过成熟阶段；(5)上侏罗统白龙冰河组烃源岩尚处于成熟阶段,其有机质丰度较高,以中等烃源岩为主,有机质主要为Ⅱ型。油源对比研究表明,(1)布曲组白云岩分离出的有机质显示出了与布曲组烃源岩的亲缘性,表明其中的油气显示可能来源于布曲组烃源岩；(2)曲色组中的液态油苗与曲色组烃源岩有着极好的亲缘性,进一步证明了羌塘盆地曲色组具备较强的生烃能力；(3)白龙冰河组中的沥青与白龙冰河组灰岩亲缘性不明显,但与该组上段的泥质烃源岩有一定的相似性,从沥青脉产状等现象初步推测沥青脉与该组泥质烃源岩同源,但仍需要进一步研究。通过上述研究,并结合区域烃源岩分布、沉积厚度等资料,本文认为下侏罗统曲色组泥页岩、上三叠统土门格拉组含煤岩系以及上侏罗统白龙冰河组碳酸盐岩烃源岩是羌塘盆地较好的的烃源岩,具备较强的生排烃能力,能为天然气水合物的形成提供较为充足的烃类气源。综合天然气水合物成藏系统的三大体系分析,羌塘盆地具备天然气水合物形成的良好前景,而上述三套烃源岩应作为羌塘盆地下一步天然气水合物资源勘查的重要目标层位。
[Abstract]:With the rapid development of our national economy, energy problems have been paid more and more attention. As a new type of energy, natural gas hydrate mainly exists in seafloor sediments and land permafrost zone. With its huge reserves, gas hydrate is expected to be an important substitute for oil and natural gas in the future. Qiangtang Basin is recognized as the best metallogenic condition and prospecting prospect of natural gas hydrate in China, but no direct evidence for the existence of gas hydrate has been obtained so far. The investigation in recent years shows that the gas source conditions are the key factors restricting the breakthrough of gas hydrate prospecting in Qiangtang Basin. In this paper, the core samples obtained from natural gas hydrate drilling test wells in Qiangtang Basin are taken as the research object. Through systematic organic geochemical analysis, several groups of hydrocarbon source rocks are evaluated. Furthermore, the gas source conditions and metallogenic potential of gas hydrate in Qiangtang Basin are discussed. The results of source rock evaluation show that (1) there is a set of mudstone mainly dark gray and gray black in the clastic rocks of the Upper Triassic Tumen Gela formation. The organic matter abundance is high, the organic matter type is mainly type 鈪，
本文编号：2416682
[Abstract]:With the rapid development of our national economy, energy problems have been paid more and more attention. As a new type of energy, natural gas hydrate mainly exists in seafloor sediments and land permafrost zone. With its huge reserves, gas hydrate is expected to be an important substitute for oil and natural gas in the future. Qiangtang Basin is recognized as the best metallogenic condition and prospecting prospect of natural gas hydrate in China, but no direct evidence for the existence of gas hydrate has been obtained so far. The investigation in recent years shows that the gas source conditions are the key factors restricting the breakthrough of gas hydrate prospecting in Qiangtang Basin. In this paper, the core samples obtained from natural gas hydrate drilling test wells in Qiangtang Basin are taken as the research object. Through systematic organic geochemical analysis, several groups of hydrocarbon source rocks are evaluated. Furthermore, the gas source conditions and metallogenic potential of gas hydrate in Qiangtang Basin are discussed. The results of source rock evaluation show that (1) there is a set of mudstone mainly dark gray and gray black in the clastic rocks of the Upper Triassic Tumen Gela formation. The organic matter abundance is high, the organic matter type is mainly type 鈪，
本文编号：2416682
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