摘要
基于东海盆地丽水凹陷天然气气样和油样的组分及稳定碳同位素分析成果,结合构造发育史、生烃史和成藏史等地质背景,研究东海盆地丽水凹陷油气成因、来源和充注过程。丽水凹陷目前发现的天然气有两类,一类是WZ13-1-1井的高含CO2、低含油型热解气气藏,另一类是LS36-1-1井、LS36-1-2井和LF-1井高含油型热解气和煤型气的混合气、同时还含有一定量CO2的气藏。天然气中烃类气体均为有机热成因气,其中油型热解气为来源于月桂峰组的高成熟气,始新世中晚期—渐新世早期充注;煤型气是来源于明月峰组的低熟气,晚期充注。LF-1井的CO2为有机成因,其余井的CO2主要来源于深部无机幔源气,充注时期约为渐新世,各井混入幔源CO2的程度不同。WZ6-1-1井原油为腐泥型高成熟度油,主要来源于月桂峰组,始新世中晚期—渐新世早期充注;LS36-1构造凝析油为腐殖型低熟油,主要来源于明月峰组,晚期充注;LF-1井原油则可能具有混源成因,较大比例原油来源于月桂峰组。
Based on the results of components and stable carbon isotopic analysis of gas and oil from the Lishui Sag, East China Sea Basin, the oil and gas genesis, source and charge process are studied by combining the history of structural evolution, oil and gas generation and migration and accumulation. The study shows that there are two types of gases in the Lishui Sag now, one is the gas with high COz content and low oil-type pyrolysis gas content found in Well WZ 13-1-1, the other is the gas with high content of the mixture of coal-type gas and oil-type pyrolysis gas and certain content of CO2 found in Well LS36-1-1, LS36-1-2 and LF-1. Hydrocarbon gases are all organic thermal gas, in which high maturity oil-type gas was from Paleocene Yueguifeng Formation and charged in middle-late Eocene-early Oligocene, and low maturity coal-type gas was from Paleocene Mingyuefeng Formation and was charged in late stage. The CO2 in Well LF-1 is of organic origin, while CO2 in other wells were derived from the deep inorganic mantle source gas charged variously in Oligocene. Oil in Well WZ6-1-1 is the high maturity sapropel type oil from Yueguifeng Formation which was charged in middle-late Eocene-early Oligocene. Condensate in Well LS36-1 is low maturity humus type oil from Mingyuefeng Formation charged in late stage. Oil in Well LF-1 may be of mixed source and greater proportion ofoil likely from Paleocene Yueguifeng Formation.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2014年第5期523-532,共10页
Petroleum Exploration and Development
基金
"十二五"国家重大油气专项(2011ZX05023-004-010)
