摘要
利用原油中含氮化合物的组成和绝对浓度的变化并结合烃类生物标志化合物指标的研究,探讨了南堡凹陷1号构造带油气的运移特征。结果表明,原油中含氮化合物的分布和组成特征较好地指示了该区的油气运移效应。随着运移作用的加强,含氮化合物绝对浓度下降,"屏蔽"型与"暴露"型化合物的比值增加,油气沿着1号断层外侧的砂体,向构造的高部位运移。这与烃类生物标志化合物的成熟度参数变化所揭示的油气运移方向相一致,也与该区油气分布和勘探实践吻合较好。但两个参数间又存在区别,用生物标志化合物的组成和分布来指示油气运移分馏作用时,由于分馏作用较弱,各井间的数值变化较小。而含氮化合物的分馏作用较强,各参数随着运移距离的增加发生显著变化,且受成熟度的影响较小,更有利于油气运移方向的判别。
Based on the composition and concentration variations of nitrogen compounds in the studied oil samples as well as the maturity indexes of saturated and aromatic biomarkers,the authors investigated the oil migration direction of 1st structural belt of Nanpu sag.The results show that the distribution and composition characteristics can obviously indicate oil fractionation effects.The concentration of nitrogen compounds decreases whereas the ratios of shielded nitrogen compounds to exposed ones increase with increasing migration.The oil will migrate to high position along the sand body on the outer side of 1st fault.This is in consistent with oil migration directions deduced from the gradient changes of hydrocarbon biomarkers.They are both consistent with the regional modes of occurrence and exploration facts of oil;nevertheless,because of fractional distillation,these two indexes are somewhat different.Due to weak fractionation,biomarker varies slowly between near-by wells;in contrast,due to strong fractionation and relatively insignificant influence of maturity,data of nitrogen compounds change significantly,which is favorable for the judgment of hydrocarbon migration.
出处
《中国地质》
CAS
CSCD
北大核心
2011年第6期1485-1492,共8页
Geology in China
基金
国家科技重大专项"大型油气田及煤层气开发"(2008ZX05050)资助
