Geochemical characteristics and formation process of natural gas in Kela 2 gas field

作     者：ZHAO Mengjun LU Shuangfang WANG Tingdong LI Jian 

作者机构：Research Institute of Petroleum Exploration and DevelopmentPetroChinaBeijing 100083China Daqing Petroleum InstituteAnda 151400.China Southwest Petroleum InstituteNanchong 637000China 

出 版 物：《Chinese Science Bulletin》 (中国科学通报)

年 卷 期：2002年第47卷第S1期

页      面：113-119页

核心收录：

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：Project of “Sources of Oil and Gas and the Formation Function in Tarim Basin”(99-111-01-03) 

主　　题：natural gas geochemistry source of natural gas reservoir formation process Kela 2 gas field. 

摘      要：On the basis of a large amount of natural gascomponents and the carbon isotope as well as some otheranalysis data in Kela 2 gas field, the geochemical character-istics, source, origin, and formation process of natural gashave been discussed. The components of gas in the field tendto be dry , and the drying coefficient is close to 1.0. Thecarbon isotope tends to be heavier, for instance, the averageof δ13C1 is -27.36‰ and that ofδ13C2 is -18.5‰. Compre-hensive analysis shows that humic natural gas in the Kuqapetroleum system comes mainly from Triassic and Jurassicsource rocks, and the contribution of Jurassic source rocks tothe pool maybe is more than that of Triassic rocks. The maincause that the gas tends to be dry and bears heavier isotopecomposition lies in the fact that Kela 2 natural gas is the ac-cumulation of late production of humic source rocks, and itis affected by the abnormal high pressure as well. Consider-ing the hydrocarbon generating and structural history, wecan regard the gas pool formation processes as twice fillingand twice adjusting （destroying）, that is, the filling anddestroying process in the early Himalayan movement and thefilling and adjusting in the late Himalayan movement.