张家政, 李胜利, 王明君, 赵广珍, 庞守吉, 张帅, 吴纪修. 南祁连盆地木里冻土区天然气水合物气源分析[J]. 海洋地质与第四纪地质, 2017, 37(5): 90-101. DOI: 10.16562/j.cnki.0256-1492.2017.05.009
引用本文: 张家政, 李胜利, 王明君, 赵广珍, 庞守吉, 张帅, 吴纪修. 南祁连盆地木里冻土区天然气水合物气源分析[J]. 海洋地质与第四纪地质, 2017, 37(5): 90-101. DOI: 10.16562/j.cnki.0256-1492.2017.05.009
ZHANG Jiazheng, LI Shengli, WANG Mingjun, ZHAO Guangzhen, PANG Shouji, ZHANG Shuai, WU Jixiu. GAS SOURCE ANALYSIS FOR GAS HYDRATE IN MULI PERMAFROST AREA OF THE SOUTHERN QILIAN BASIN[J]. Marine Geology & Quaternary Geology, 2017, 37(5): 90-101. DOI: 10.16562/j.cnki.0256-1492.2017.05.009
Citation: ZHANG Jiazheng, LI Shengli, WANG Mingjun, ZHAO Guangzhen, PANG Shouji, ZHANG Shuai, WU Jixiu. GAS SOURCE ANALYSIS FOR GAS HYDRATE IN MULI PERMAFROST AREA OF THE SOUTHERN QILIAN BASIN[J]. Marine Geology & Quaternary Geology, 2017, 37(5): 90-101. DOI: 10.16562/j.cnki.0256-1492.2017.05.009

南祁连盆地木里冻土区天然气水合物气源分析

GAS SOURCE ANALYSIS FOR GAS HYDRATE IN MULI PERMAFROST AREA OF THE SOUTHERN QILIAN BASIN

  • 摘要: 南祁连盆地木里冻土区天然气水合物的气体成因或来源存在不同观点,目前还没有统一认识,这直接影响到水合物的资源评价及下一步勘探方向。文章依托前人研究成果及新近钻探木参1井、木参2井及SK-0井资料,对比分析中侏罗统与上三叠统尕勒得寺组两套烃源岩,结合天然气水合物气体组成与碳氢同位素特征进行综合研究,结果表明:南祁连盆地木里冻土区天然气水合物的气体以轻烃为主,具湿气特征,其同位素表现为正碳同位素系列,为有机成因,成气母质主要为腐泥型干酪根的油型气,是热演化程度较低的原油伴生气;少量与微生物成因气有关,与煤层气关系不大。中侏罗统有机质丰度高、类型较好,镜质体反射率Ro在0.48%~1.14%之间,处于生油高峰期,生油过程中原油伴生气为天然气水合物的主要气体来源;上三叠统尕勒得寺组有机质丰度较高、类型较好,但成熟度高,处于生凝析气或裂解气阶段,总体生排烃能力差,从气源对比分析来看对天然气水合物气体来源贡献不大。

     

    Abstract: There are hot debates on the gas source of gas hydrate in the Muli permafrost area of the Southern Qilian Basin. The understanding of gas source directly affects the gas hydrate resource evaluation and exploration. Based on the previous research results and the newly acquired data from the Wells of Mucan 1, Mucan 2 and SK-0, the authors have made a comparison of the source rocks in the Middle Jurassic and Upper Triassic Galedesi Formation. Comprehensive studies on gas compositions as well as carbon and hydrogen isotopic characteristics were also performed. The results show that the gases in the Muli permafrost area of southern Qilian Basin is mainly composed of light hydrocarbon and characterized by wet gases. The isotopic composition of the gas hydrate, which is characterized by positive carbon isotopic series, indicates that the gas is formed by pyrolysis of organic matter and the parent gas is a kind of sapropelic kerogen oil-based gas with low thermal evolution. It is mainly oil associated gas with a small amount of microbial gas and coal-bed methane. The organic matter in the Middle Jurassic is of high abundance and good type, of which the vitrinite reflectivity Ro is between 0.48% and 1.14%, indicating that it is in the peak period of oil generation. The oil associated gas is the main source of the gas hydrate. The organic matter is also abundant and of good type in the Galedesi Formation of Upper Triassic, but the maturity is too high. It remains in the stages of condensate gas or pyrolytic gas, and the total hydrocarbon generation and discharge are poor. As a source of hydrate gas, its contribution is little.

     

/

返回文章
返回