摘要
利用正构烷烃生物标志化合物分析参数,以及全油碳和单体烃碳同位素分布特征,结合天然气组成和碳同位素特征,对柴达木盆地东坪地区油气的来源及成因类型进行了研究。结果表明:东坪1井凝析油正构烷烃的碳优势指数(CPI)为1.021,奇偶优势指数(OEP)为1.004,表现出奇碳和偶碳数优势相当的高成熟原油特征;姥鲛烷(Pr)/植烷(Ph)为3.06,表现为姥鲛烷优势;凝析油碳同位素含量为-31.25‰,与柴达木盆地北缘地区侏罗系湖沼相原油碳同位素相近,其单体烃碳同位素的分布表征烃源岩为陆源高等植物有机质生物源。综合分析认为:东坪地区油气来自以陆源物质为主要母质输入类型的侏罗系源岩,天然气属于典型的煤型气。
Using the biomarker parameters of n-alkane, the carbon isotope of full oil and the distribution pattern of single molecule, combined with the composition and carbon isotopic characteristics of natural gas, this paper discussed the oil and gas origin and genesis in Dongping area, Qaidam Basin. The results show that the n-alkane odd and even carbon number predominance of condensate oil in Dongping 1 well is equivalent (CPI =1.021, OEP =1.004), showing the characteristic of high-mature crude oil. The Pr/Ph is 3.06, showing the pristane advantage. The carbon isotope of condensate oil(-31.25‰) is close to the carbon isotope of the Jurassic limnetic facies crude oil in the northern margin of Qaidam Basin, and the distribution characteristics of single molecule carbon isotope demonstrate the organic biological source of terrigenous higher plants. It is considered that the oil and gas in Dongping area are from Jurassic hydrocarbon source rocks, and the natural gas is a typical coal-type gas.
出处
《岩性油气藏》
CSCD
2013年第3期17-20,42,共5页
Lithologic Reservoirs
基金
中国石油重大科技专项"柴达木盆地建设千万吨油气田综合配套技术研究"(编号:2011E-03)资助
