CAJ | 학술논문

对柴达木盆地乌南油田原油样品的地球化学系统分析表明：样品中正构烷烃系列碳数分布具有双重性模式,Pr/Ph值〈0.5,呈强植烷优势;具有相对较高含量的三环萜烷和伽马蜡烷,藿烷C35/C34值基本上≤1;指示了乌南油田原油形成于半咸水—咸水湖相较强还原沉积环境,母质来源主要为低等水生生物,藿烷和甾烷成熟度参数反映其主要为低成熟原油。在此基础上开展油源对比研究,指出乌南油田原油和扎哈—切克里克生烃凹陷下干柴沟组烃源岩之间的生物标志化合物对比性很好。原油类型的一致性为应用含氮化合物探讨原油运移提供了基础条件。含氮化合物分析结果反映随着运移距离的增加,咔唑类化合物浓度存在减小的趋势,而异构体化合物中屏蔽型化合物相对富集,表明乌南油田原油自西注入,向北和东南方向运移。由此确定位于乌南油田西侧的扎哈—切克里克生烃凹陷为其油源区,从而为该区的进一步勘探提供了理论指导。
대시체목분지오남유전원유양품적지구화학계통분석표명：양품중정구완경계렬탄수분포구유쌍중성모식,Pr/Ph치〈0.5,정강식완우세;구유상대교고함량적삼배첩완화가마사완,곽완C35/C34치기본상≤1;지시료오남유전원유형성우반함수—함수호상교강환원침적배경,모질래원주요위저등수생생물,곽완화치완성숙도삼수반영기주요위저성숙원유。재차기출상개전유원대비연구,지출오남유전원유화찰합—절극리극생경요함하간시구조경원암지간적생물표지화합물대비성흔호。원유류형적일치성위응용함담화합물탐토원유운이제공료기출조건。함담화합물분석결과반영수착운이거리적증가,잡서류화합물농도존재감소적추세,이이구체화합물중병폐형화합물상대부집,표명오남유전원유자서주입,향북화동남방향운이。유차학정위우오남유전서측적찰합—절극리극생경요함위기유원구,종이위해구적진일보감탐제공료이론지도。
The geochemical features of the crude oil samples collected from the Wunan Oilfield in southwestern margin of Qaidam Basin were analyzed.The result shows that the n-alkanes presented a bimodal distribution pattern（odd-toeven and even-to-odd carbon predominance）,with the low ratios for both Pr/Ph（ 0.5） and C 35-Hopane/C 34-Hopane（ 1.0）,and high contents of tricyclic-terpanes and gammacerane,which indicates that the crude oil formed in a midsalty to salty water reduction depositional environment,and the parent material are mainly from the lower aquatic organisms.Moreover,maturity parameters of hopane and sterane reflect its lowmaturity of crude oil.According to the oilsource correlation,the crude oil derived from the Xiaganchaigou Formation（E 3 2） of Zhaha-Qiekelike depression.The type of crude oil is more consistent from the same source,thus the significant oil-migration effects of nitrogen compounds in the oil are observed.The composition and relative abundance of nitrogen compounds in the crude oil were used to discuss the petroleum migration in the Wunan oilfield.With the increasing of the migration distance,the concentration of nitrogen compounds is decreased,which indicates that crude oil generated on its west adjacent depression,and migrated from west to north and from northwest to southeast.It is concluded that the crude oil in the study area came from the western Zhaha-Qiekelike depression.