鄂尔多斯盆地志丹油田原油含氮化合物特征与石油充注

针对鄂尔多斯盆地延长组致密油充注、运移、成藏研究中存在的问题，运用原油中性含氮化合物测试技术，研究了志丹油田纸坊区延长组石油充注方向。结果表明：纸坊区延长组原油具有相同的成因和相似的热演化程度；石油总体由中部向西部、东北部发生充注，具体表现为：沿着充注方向，原油中性含氮化合物总量增加、原油成熟度逐渐降低、暴露型化合物相对含量增加。原油充注方向与烃源岩厚度变薄所指示的方向一致，且以短距离充注为主。研究结果对延长组致密油成藏机理研究及勘探选区评价具有积极意义。

Characteristics of Nitrogen Compoundsin Crude Oil and Their Bearing on Oil Filling Processin Zhidan Oilfield,Ordos Basin

Oil charging, migration and accumulation into the tight reservoir of the Yanchang Formation in the Ordos Basin remain controversary. In order to solve the problem, oil charging direction of the Yanchang Formation in the Zhifang area of the Zhidan Oilfield was studied as a case using the neutral nitrogen compounds of crude oil as indicators. Results show that all the crude oil in the Yanchang Formation of the Zhifang area presents the same source and similar thermal evolutionary degree. They were gradually filled from the central part to the west and northeast. Along the direction of oil charging, the total of neutral nitrogen compounds in crude oil increases, the maturity of crude oil decreases, and the relative content of exposed compounds increases. The direction of crude oil charging is consistent with the thinning out of the source rock, and the migration distance is in fact very short. The research results are helpful to the study of the formation of oil fields in tight oil reservoirs of the Yanchang Formation.