东营凹陷北部沙四段盐下天然气成因及来源

Genesis and source of the natural gas under the Es_4 salt-gypsum beds in north Dongying Depression

东营凹陷北部沙四段盐下天然气以湿气为主,产状为气层气和凝析气。应用天然气组成、碳同位素、轻烃参数和储层流体包裹体等指标分析了天然气的成因类型。同时以各套烃源岩的气源条件研究为基础,应用生物标志化合物,从生气母质和成熟度角度,探讨了天然气的来源。结果表明,东营凹陷北部沙四段盐下天然气为油型热解气,主要来源于沙四段下亚段烃源岩。

Wet natural gas,as the unassociated gas and the condensate gas,is dominant under Ks4 salt -gypsum beds of north Donying Depression.The genesis of gas is analyzed according to composition,carbon isotope,light hydrocarbon parameter,and fluid inclusionin reservoirs.Furthermore,based on the research of the gas generating condition,the source rocks are investigated by the bi-omarker analysis from the aspects of gas generating mother materialand maturity.It is concluded that the natural gas under the Es4 salt-gyp...