应用含氮化合物探讨油气运移和注入方向

STUDY OF OIL MIGRATION AND INJECTION DIRECTIONS BY NITROGEN COMPOUNDS

利用原油中含氮化合物组成和绝对浓度的变化,结合烃类生物标志物指标研究,该文探讨了我国渤海海域曹妃甸及临近地区的油气运移特征和注入方向。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"型或"半屏蔽"型化合物的比值增加。沙垒田凸起油气运移方向是自东向西,注入点在凸起东侧。沙东南构造带油气存在2个运移和注入方向,即北东方向和西南方向。石臼坨凸起及倾没端油气是从西北方向运移和注入的。这与烃类生物标志物成熟度参数变化所揭示的油气运移和注入方向相一致,也与该区油气分布和勘探实践相吻合。

Based on the composition and concentration changes of nitrogen compounds in the study oil samples as well as the maturity indexes of saturated and aromatic biomarkers, this paper investigated the oil migration and injection direction of Caofeidian and nearby areas in the offshore part of the Bohai Bay Basin. The results showed that the distribution and composition characteristics can indicate oil fractionation effects. With the increasing of oil migration effects, the concentration of nitrogen compounds decreased whereas the ratios of shielded nitrogen compounds to exposed or semi-shielded ones increased. The oil migration and injection direction of the Shaleitian Uplift was from east to west, with the main charging point in the east. Two oil migration and injection directions (i.e., eastnorth and southwest) were found in the Shadongnan tectonic zone. Oil in the Shijiutuo Uplift and the inclined end migrated from northwest. This is consistent with oil migration directions deduced from the gradient changes of hydrocarbon biomarkers. All these conclusions are also accorded with the regional oil occurrences and exploration facts.