石油实验地质
石油實驗地質
석유실험지질
EXPERIMENTAL PETROLEUM GEOLOGY
2015年
1期
64-70,79
,共8页
降胆甾烷%硅藻%沟鞭藻%寒武系%塔里木盆地
降膽甾烷%硅藻%溝鞭藻%寒武繫%塔裏木盆地
강담치완%규조%구편조%한무계%탑리목분지
norcholestane%diatom%dinoflagellate%Cambrian%Tarim Basin
塔河油田奥陶系原油中都检测出丰富的C26降胆甾烷系列。大多数原油24－降胆甾烷含量相对27－降胆甾烷低，而九区T904和塔东地区TD2井原油24－降胆甾烷含量相对较高。以LN46、BD2等井为代表的上奥陶统灰岩、泥灰岩具有类似于塔河油田奥陶系原油的C26降胆甾烷分布特征，而以TD2井、和4井及柯坪露头为代表的寒武系黑色泥岩和灰色灰岩具有类似于T904和TD2井原油的C26降胆甾烷分布特征。该文提出判识寒武系烃源层油气来源的C26降胆甾烷地球化学判识标准为：NCR[24／（24＋27）－降胆甾烷]＞0．50，NDR[24／（24＋27）－降重排胆甾烷]＞0．35；上奥陶统烃源层油气来源的C26降胆甾烷判识标准为：NCR＜0．40，NDR＜0．35。结果表明C26降胆甾烷不仅是塔河油田奥陶系油藏进行原油族群划分的特征分子标志物，也为研究硅藻、沟鞭藻等藻类的起源和演化以及塔里木盆地古板块构造运动提供了有力的分子地球化学证据。
塔河油田奧陶繫原油中都檢測齣豐富的C26降膽甾烷繫列。大多數原油24－降膽甾烷含量相對27－降膽甾烷低，而九區T904和塔東地區TD2井原油24－降膽甾烷含量相對較高。以LN46、BD2等井為代錶的上奧陶統灰巖、泥灰巖具有類似于塔河油田奧陶繫原油的C26降膽甾烷分佈特徵，而以TD2井、和4井及柯坪露頭為代錶的寒武繫黑色泥巖和灰色灰巖具有類似于T904和TD2井原油的C26降膽甾烷分佈特徵。該文提齣判識寒武繫烴源層油氣來源的C26降膽甾烷地毬化學判識標準為：NCR[24／（24＋27）－降膽甾烷]＞0．50，NDR[24／（24＋27）－降重排膽甾烷]＞0．35；上奧陶統烴源層油氣來源的C26降膽甾烷判識標準為：NCR＜0．40，NDR＜0．35。結果錶明C26降膽甾烷不僅是塔河油田奧陶繫油藏進行原油族群劃分的特徵分子標誌物，也為研究硅藻、溝鞭藻等藻類的起源和縯化以及塔裏木盆地古闆塊構造運動提供瞭有力的分子地毬化學證據。
탑하유전오도계원유중도검측출봉부적C26강담치완계렬。대다수원유24－강담치완함량상대27－강담치완저，이구구T904화탑동지구TD2정원유24－강담치완함량상대교고。이LN46、BD2등정위대표적상오도통회암、니회암구유유사우탑하유전오도계원유적C26강담치완분포특정，이이TD2정、화4정급가평로두위대표적한무계흑색니암화회색회암구유유사우T904화TD2정원유적C26강담치완분포특정。해문제출판식한무계경원층유기래원적C26강담치완지구화학판식표준위：NCR[24／（24＋27）－강담치완]＞0．50，NDR[24／（24＋27）－강중배담치완]＞0．35；상오도통경원층유기래원적C26강담치완판식표준위：NCR＜0．40，NDR＜0．35。결과표명C26강담치완불부시탑하유전오도계유장진행원유족군화분적특정분자표지물，야위연구규조、구편조등조류적기원화연화이급탑리목분지고판괴구조운동제공료유력적분자지구화학증거。
A series of C26 norcholestanes was detected in the Ordovician crude oils from the Tahe Oilfield, the Tarim Basin, northwest China. The abundance of 24?norcholestanes in most of the Ordovician crude oils was lower than that of 27?norcholestanes. The oils from well T904 in the eastern Tahe Oilfield and well TD2 in the eastern Tarim Basin, however, were characterized by relatively higher 24?norcholestane abundance. The distribution of C26 norcholestane of the Upper Ordovician marls from the wells LN46 and BD2 resembled that of the most Ordovician crude oils from the Tahe Oilfield. The distribution of C26 norcholestanes in typical Cambrian black shales and gray limestones from the wells TD2, He4 and outcrops from Keping profile resembled that of the crude oils from the wells T904 and TD2. Criteria are proposed relative to C26 norcholestanes that could be used to classify oil families within the Ordovician reservoirs. Oils with NCR (defined as 24/(24+27)?norcholestanes) >0.50 and NDR (defined as 24/(24+27)?nordia?cholestanes) >0. 35 were thought to be derived from the Cambrian source rocks, and oils with NCR<0. 40 and NDR<0.35 were thought to be derived from the Upper Ordovician source rocks. Therefore, C26 norcholestanes were effective molecular markers to classify oil genetic families in the Tahe Oilfield. They could also provide molecular evidence for the origin and evolution of diatoms and dinoflagellates and the plate drift of the Tarim Basin.
