CAJ | 학술논문

珠江口盆地原油富含多种类型的特殊萜烷,经GC-MS分析,在二环倍半萜烷系列中检出2,2,4a,7,8-五甲基-十氢化萘(新 C15二环萜烷)；三、四环萜烷中鉴定出降 A-奥利烷及相关化合物,并检测到一个 C24未知结构的四环萜烷。新C15二环萜烷和降A-奥利烷源于奥利烷类先质物在成岩作用过程中的降解作用,可指示被子植物有机源的输入。这些奥利烷降解物的含量和分布在研究区原油中呈区域性变化。新C15二环萜烷 A/补身烷和降 A-奥利烷/C24未知四环萜烷比值可作为生源和指相参数,区分各坳陷或凹陷之间及内部的不同类型原油。盆地南部的珠二坳陷白云凹陷及番禺低隆起原油中这些陆源标志物很丰富,这两个参数值大都分别高于1.0和9.0,表明其烃源岩有机质生源中被子植物输入比例较高,且沉积环境的氧化性较强。盆地东部的珠一坳陷各凹陷原油中,这些奥利烷类降解物均相对较少,两个比值分别多在0.5和3.0之下,指示成油母质中陆源有机质较少。盆地西部的珠三坳陷文昌凹陷及邻区原油中,这些被子植物源标志物的含量变化在前两个坳陷原油之间,其中文昌A凹陷原油相对较高。
주강구분지원유부함다충류형적특수첩완,경GC-MS분석,재이배배반첩완계렬중검출2,2,4a,7,8-오갑기-십경화내(신 C15이배첩완)；삼、사배첩완중감정출강 A-오리완급상관화합물,병검측도일개 C24미지결구적사배첩완。신C15이배첩완화강A-오리완원우오리완류선질물재성암작용과정중적강해작용,가지시피자식물유궤원적수입。저사오리완강해물적함량화분포재연구구원유중정구역성변화。신C15이배첩완 A/보신완화강 A-오리완/C24미지사배첩완비치가작위생원화지상삼수,구분각요함혹요함지간급내부적불동류형원유。분지남부적주이요함백운요함급번우저륭기원유중저사륙원표지물흔봉부,저량개삼수치대도분별고우1.0화9.0,표명기경원암유궤질생원중피자식물수입비례교고,차침적배경적양화성교강。분지동부적주일요함각요함원유중,저사오리완류강해물균상대교소,량개비치분별다재0.5화3.0지하,지시성유모질중륙원유궤질교소。분지서부적주삼요함문창요함급린구원유중,저사피자식물원표지물적함량변화재전량개요함원유지간,기중문창A요함원유상대교고。
The crude oils fromthePearl River MouthBasin are rich in various kinds of uncommon terpanes.Based on GC-MSanalytical data,2, 2, 4a, 7, 8-pentamethyl-decalin (novel C15 sesquiterpane),de-A-oleanane and related tricyclic and tetracyclic terpanes, as well as an unknown C24 tetracyclic terpane, are identified in this study.The novel C15 sesquiterpane and de-A-oleananeare probably derived from degradation of oleanoidsduring diagenesis, so itcan be useful as markers of angiosperm input.In addition, these compounds in thestudied oils exhibit a regional change in relative abundance and distribution. Novel C15 sesquiterpane/drimane and de-A-oleanane/C24 unknown tetracyclic terpane ratios can be used as indicators of biological source and depositional environment, to recognize different kinds oftheoils in various depressions of the Pearl River Mouth Basin.For example, the oils fromBaiyun sag and Panyu low uplift intheZhu-Ⅱdepression, southern region of this basinpresent abundant terrigenous-derived biomarkers.Their novel C15 sesquiterpane/drimane and de-A-oleanane/C24unknown tetracyclic terpane ratios are higher than 1.0 and 9.0, respectively, indicating a significant input of angiosperm for organic source and an oxic depositional condition.In contrast, the oils from the various sags of Zhu-Ⅰdepression in the eastern basin contain an obviously lower concentration of the oleanane-degraded alkanes, and their C15 sesquiterpane/drimane and de-A-oleanane/C24 unknown tetracyclic terpane ratios are below 0.5 and 3.0, respectively, suggesting a less terrestrial input in biological source. The angiosperm-derived indicators in the oils from Wenchang sag and adjacent area in Zhu-Ⅲ depression of the western basin display middle abundances ranging between the oils in previous two depressions, with a relatively higher amount in the oils of Wenchang sub-sag A.