【摘要】 塔里木盆地东河砂岩是海相油气的重要勘探领域。为研究东河砂岩天然气成因、油藏类型及油气运移方向,以哈得逊油田东河砂岩油藏原油伴生气为研究对象,在天然气组分数据可靠性评估基础上,对烷烃气组分和非烷烃气组分的含量、同位素特征及分布规律进行了详细研究,探讨了天然气组分成因,详细分析了东河砂岩油藏类型,并对油气运移路径进行了推测,形成以下主要认识:①哈得逊油田东河砂岩油藏原油伴生气为油型气,总体具有N2含量高、干燥系数低及CO2含量低的特征;高含量N2为腐泥型有机质在成熟阶段热解生成,CO2是有机和无机成因的混合物。②哈得逊油田东河砂岩油藏由西南侧哈得4井区油藏、东南侧哈得1井区油藏和北部井区油藏(哈得113井—哈得111井—哈得4-51井)3个相对独立的油藏共同组成,油藏类型分别为构造油藏、构造—岩性油藏和岩性—地层油藏。③与哈得1井区油藏天然气相比,哈得4井区油藏天然气干燥系数低,N2和CO2含量高,δ13C1值、δ15 N值和δ13 CCO2值偏高,且烷烃气δ13 C值部分倒转;这可能是成藏后期哈得4油藏天然气的泄漏导致。④现今哈得逊油田东河砂岩油藏已基本达到平衡,自北向南大规律油气运移难于形成现今天然气组分和同位素分布规律。推测哈得逊东河砂岩油藏可能是经下伏断裂,由下部奥陶系古油藏调整而来。更多还原

【Abstract】 Donghe sandstone is an important exploration target of marine origin hydrocarbon in Tarim Basin.The main purpose of this article is to study the origin of natural gases,reservoir type,as well as hydrocarbon migration direction and path of Donghe sandstone reservoir,Hadexun oilfield.Firstly,based on the data reliability assessment of natural gas compositions,the composition contents,isotopes and their distributionwerestudiedindetail.Then,theoriginofnaturalgasesandthereservoirtype)werediscussed,andthehydrocarbonmigrationpathwasspeculated.Finally,thefollowing conclusions were formed.(1)The crude oil associated gases of Donghe sandstone reservoir in Hadexun Oilfield were oil-type,with high content of N2,low dry coefficient and less CO2content.High level of N2content was formed by sapropelic organic matter during mature stage,and CO2 was a mixture of organic and inorganic origin.(2)Donghe sandstone reservoir in Hadexun oilfield actually consists of three relatively independent reservoirs:Hade 4well area reservoir,Hade 1well area reservoir and northern wells reservoir(HD113well-HD111well-HD4-51well).They are structural type,structural-lithologic type and lithologystratigraphic type respectively.(3)With partial reversal in the carbon isotope values of alkane gases,the natural gases of Hade 4well area reservoir were characterized by low dry coefficient,high content of N2 and CO2,and weightedδ13 C1,δ15 N andδ13 CCO2 values compared with those from Hade 1well area reservoir. This phenomenon may be due to natural gas leakage in the Hade 4well area reservoir after hydrocarbon accumulation.(4)At present,Donghe sandstone reservoir of Hadexun Oilfield has already or almost reached the equilibrium state.It′s difficult to form the gas composition and isotope distribution patterns by long distance migration of hydrocarbon from north to south.So,this article speculate that the Donghe sandstone reservoirs were adjusted from the underneath Ordovician reservoir through faults.更多还原