摘要
通过有压力的黄金管封闭体系生烃模拟实验和GC IRMS测定,结合GOR IsotopeKinetics专用软件,求取了塔里木盆地库车坳陷三叠系—侏罗系烃源岩生成甲烷的碳同位素动力学参数。结合地质背景,探讨了克拉2气田天然气的成因。克拉2气田天然气主要来源于早中侏罗世煤系烃源岩,属阶段捕获气,为- 5Ma以来的天然气聚集,对应成熟度范围Ro为1.3%～2 .5 %。在此基础上,建立了克拉2气田天然气运聚成藏动力学模式。
Based on thermal simulation experiment of closed gold tube system under the given pressure (50 MPa) and analysis of methane carbon isotopes with GC-IRMS isotope mass spectrography, combined with the kinetic modeling calculation by using the GOR-Isotope Kinetics software, this paper obtained the carbon isotopic kinetic parameters of methane generated from Triassic-Jurassic coal measures source rocks in the Kuqa depression, Tarim Basin. The average activation energies of Jurassic coal, Jurassic mudstone and Triassic mudstone samples selected from Well Yinan 2 were 227.90 kJ/mol, 204.84 kJ/mol, 230.63 kJ/mol, respectively. The kinetic modelling results of methane carbon isotopes were generally accorded with the laboratory pyrolysis data. It is demonstrated that the laboratory pyrolysis data could be extrapolated and applied to the actual geological condition by using the method of carbon isotope kinetics. Combined with the geological background, the source, maturity, and accumulation time of natural gas in Kela-2 gas field were further discussed. Natural gas of Kela-2 gas field was mainly derived from the Middle and Lower Jurassic coal-bearing source rocks, and belonged to the staged cumulative gas. The gas was chiefly accumulated in the last 5Ma, with its Ro value ranging from 1.3% to 2.5%. On the basis of the above research, a kinetic model of natural gas migration and accumulation in Kela-2 gas field was established. This kind of study may provide a new idea for natural gas quantitative assessment and dynamic research.
出处
《高校地质学报》
CAS
CSCD
北大核心
2005年第1期137-144,共8页
Geological Journal of China Universities
基金
国家"十五"重点科技攻关项目 (2 0 0 1BA60 5A0 2 -0 3 -0 1)
国家自然科学基金 (4 0 0 72 0 43 )
中国博士后科学基金 (2 0 0 2 0 3 12 82 )
中国科学院知识创新工程重要方向性项目 (KZCX 2 -110 )资助项目
关键词
天然气形成
甲烷碳同位素动力学
生烃模拟实验
烃源岩
塔里木盆地
formation of natural gas
methane carbon isotope kinetics
thermal simulation experiment
hydrocarbon source rock
Tarim Basin.
