CAJ | 학술논문

通过对富县地区延长组长6～长9原油及烃源岩的地球化学特征综合对比分析，认为研究区存在长7、长9两套有效烃源岩。长7烃源岩有机质类型为Ⅰ～Ⅱ1型，长9烃源岩的有机类型为Ⅱ1～Ⅱ2型。长7、长9烃源岩中Ts相对含量高于Tm，均达到成熟阶段。长7烃源岩五环三萜烷中C30藿烷丰度相对高于C29藿烷丰度，C30 RH/C29 Ts<2，长7形成于还原环境；长9烃源岩中C30藿烷丰度与C29藿烷丰度基本相似，C30 RH/C29 Ts>2，表明长9为弱氧化-弱还原环境。长6原油饱/芳比值较低，长8原油饱/芳比值较高，说明长6原油和长8原油不同源。长7烃源岩与长9烃源岩在生物标志化合物特征上有明显区别。规则甾烷C27-C28-C29αααR指纹分布样式上，长7呈现“L”型，长9呈现偏“V”型与反“L”型，长8原油呈现偏“V”型分布。研究区长8原油主要来源于长9烃源岩。
통과대부현지구연장조장6～장9원유급경원암적지구화학특정종합대비분석，인위연구구존재장7、장9량투유효경원암。장7경원암유궤질류형위Ⅰ～Ⅱ1형，장9경원암적유궤류형위Ⅱ1～Ⅱ2형。장7、장9경원암중Ts상대함량고우Tm，균체도성숙계단。장7경원암오배삼첩완중C30곽완봉도상대고우C29곽완봉도，C30 RH/C29 Ts<2，장7형성우환원배경；장9경원암중C30곽완봉도여C29곽완봉도기본상사，C30 RH/C29 Ts>2，표명장9위약양화-약환원배경。장6원유포/방비치교저，장8원유포/방비치교고，설명장6원유화장8원유불동원。장7경원암여장9경원암재생물표지화합물특정상유명현구별。규칙치완C27-C28-C29αααR지문분포양식상，장7정현“L”형，장9정현편“V”형여반“L”형，장8원유정현편“V”형분포。연구구장8원유주요래원우장9경원암。
Geochemical correlation of the crude oil and source rocks from the Chang-8 to the Chang-9 oil reservoirs in the Yanchang Formation,Fuxian region,Ordos Basin indicates that there occur the Chang-7 and Chang-9 effective source rocks with higher organic matter abundances. The organic matter in the Chang-7 source rocks belongs to the I-II1 types,and that in the Chang-9 source rocks belongs to the II1-II2 types,both of which have higher Ts contents than Tm contents,suggesting a mature stage of the source rocks. In the Chang-7 source rocks, C30 hopane abundances in pentacycloterpane are larger than C29 hopane abundances and the C30 RH/ C29 Ts ratios<2,indicating a reduction environment of the Chang-7 source rocks. In the Chang-9 source rocks,a general similarity in C30 hopane abundances and C29 hopane abundances and C30 RH/ C29 Ts ratios>2 indicates the weak oxidation-weak reduction environments of the Chang-9 source rocks. The saturated hydrocarbons/aromatic hydrocarbons ratios are lower in the Chang-6 source rocks than those in the Chang-8 source rocks,indicating different sources of the crude oil from the Chang-6 and Chang-8 source rocks. As for the biomarkers,the C27-C28-C29 αααR distribution patterns of regular steranes in the Chang-7 source rocks display the“L”type,those in the Chang-9 source rocks display the“V”or inverse“L”types,and those in the Chang-8 source rocks display the“V”type. The crude oil in the Chang-8 oil reservoirs mainly stemmed from the Chang-9 source rocks in the study area.