Geochemical characteristics of natural gas at giant accumulations in China

被引:23
作者
Dai, J. [1 ]
Li, J.
Ding, W.
Hu, G.
Luo, X.
Hou, L.
Tao, S.
Zhang, W.
Zhu, G.
机构
[1] PetroChina, Res Inst Petr Explorat & Dev, Beijing 100083, Peoples R China
[2] Zhejiang Univ, Dept Earth Sci, Hangzhou 310027, Peoples R China
[3] Univ Petr, Fac Nat Resources & Informat Technol, Beijing 102200, Peoples R China
[4] PetroChina, Changqing Oilfield Co, Inst Explorat & Dev, Xian 710021, Peoples R China
关键词
giant gasfields; China; Tarim Basin; Ordos Basin; natural gas; isotope ratios;
D O I
10.1111/j.1747-5457.2007.00275.x
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
A total of six giant gasfields each with proven reserves of more than 100 billion cubic metres are present in the Ordos and Tarim Basins, China. The gasfields are Sulige, Yulin, Wushenqi, Da'niudi and Jingbian in the Ordos Basin, and Kela 2 in the Tarim Basin. In this paper, we report on the geochemical characteristics of the natural gas at these fields based on studies of gas composition (150 samples), together with stable isotope data (143 samples) and helium isotope data (21 samples). Results show that the gases have high contents of C1-4 alkanes (generally over 90%) and minor contents of CO2 (below 3%). The generally high delta C-13 values of C-1-C-4 hydrocarbons indicates a significant contribution from humic source rocks such as Permian-Carboniferous and Mid-Lower Jurassic coal measures. delta(13) C-1, delta C-13(2), delta C-13(3) and delta C-13(4) values for gases in Upper Palaeozoic reservoirs were -35 to -32 parts per thousand, -28 to -24 parts per thousand, -27 to -24 parts per thousand, and -23.5 to -22 parts per thousand, respectively. The delta C-13(iC4) value is higher than that of the delta C-13(nC4 center dot) He-3/He-4 ratios vary from 10(-7) to 10(-8), indicating that the helium is of crustal (as opposed to mantle) origin. The CH4/ He-3 ratio is 10(10) - 10(11), indicating that the CH4 is of biogenic origin. None of the data is consistent with an abiogenic origin for gas in the Ordos Basin.
引用
收藏
页码:275 / 286
页数:12
相关论文
共 42 条
[1]  
AKIKO U, 1983, P ANN GEOCH
[2]  
[Anonymous], 2003, NATURAL GAS GEOSCIEN
[3]  
[陈安定 Chen Anding], 2002, [石油勘探与开发, Petroleum Exploration and Development], V29, P33
[4]  
Chen H P, 1994, Bioorg Med Chem, V2, P1, DOI 10.1016/S0968-0896(00)82195-1
[5]  
Dai J., 1995, CONDITIONS GOVERNING
[6]  
DAI J, 1992, NATURAL GAS GEOLOGY, V1, P56
[7]  
DAI J, 2005, ORGANIC GEOCHEMISTRY, V35, P1617
[8]  
DAI J, 1980, ACTA PETROLEI SINICA, V4, P27
[9]  
[戴金星 Dai Jinxing], 2002, [新疆石油地质, Xinjiang Petroleum Geology], V23, P357
[10]  
[戴金星 Dai Jinxing], 2005, [石油勘探与开发, Petroleum Exploration and Development], V32, P1