摘要
为了深入认识川西坳陷须家河组天然气成因类型及气源,利用天然气中稀有气体、组分、碳同位素、轻烃等地球化学资料对该区天然气成因类型进行了分析,根据气、源轻烃配对参数对天然气来源进行追踪.稀有气体分析表明,研究区天然气为壳源有机成因气.组分分析表明,研究区天然气主要为腐殖型干酪根裂解成因煤型气,须二段部分天然气为原油裂解成因油型气.碳同位素与轻烃分析均表明,研究区天然气以煤型气为主,须二段存在少量油型气.组分、碳同位素与轻烃三方面分析结果充分肯定了须二段油型气的存在.因此,川西坳陷须家河组天然气成因类型并不是典型的煤型气,而是以煤型气为主,同时有少量油裂解成因油型气存在.天然气轻烃气源追踪结果表明,须四段天然气主要来自须四段与须五段烃源岩,须二段天然气主要来自须二段烃源岩,须二段中的油型气来自须一段烃源岩.
The genetic types of the natural gas in Xujiahe Formation of the west Sichuan Depression are studied according to the analysis of rare gas,component,carbon isotope and light hydrocarbon in the natural gas,and the sources of the natural gas in this area are traced by comparing the light hydrocarbon parameters of the natural gas with source rock. The analysis of the rare gas shows that the natural gas of the studied area is crustal organic genetic gas. Component analysis shows that the natural gas is mainly the coal-related gas from humic kerogen cracking,a part of the natural gas of T3 x2formation is oil cracking gas. The analysis of carbon isotope and light hydrocarbon all indicates that the natural gas is mainly coal-related gas,a part of natural gas of T3 x2formation is oil-type gas. Based on the results above,it is held that the natural gas in Xujiahe Formation of the west Sichuan Depression is organic gas,the genetic type of the natural gas is not typical coal-related gas,but the major natural gas is coal-related gas and a small amount of oil-type gas exists in T3 x2 formation. The correlation of natural gas with source rock indicates that the natural gas in T3 x4formation is from T3 x4and T3 x5source rock,the natural gas in T3 x2formation is mainly from T3 x2,and the oil-type gas in T3 x2is from T3 x1source rock.
出处
《西安石油大学学报（自然科学版）》
CAS
北大核心
2013年第6期8-13,21,共7页
Journal of Xi’an Shiyou University（Natural Science Edition）
基金
国家自然科学基金项目(编号:41172119)
关键词
川西坳陷
须家河组
天然气成因
气源
稀有气体
碳同位素
轻烃
west Sichuan Depression
Xujiahe Formation
genesis of natural gas
gas source
rare gas
carbon isotope
light hydrocarbon
