Quantitative prediction of the oil-bearing height of Tertiary stratigraphic reservoirs in Jiyang Depression

Abstract

The Tertiary stratigraphic reservoirs in Jiyang Depression are characterized by small buried-depth, long distance of trap from source, low oil-bearing height and poor oil physical property. Oil-bearing height is mainly determined by four factors: expulsion rate of source rock, migration distance, dip angle of carrier bed and capillary resistance force. Of these four factors, the expulsion rate can be expressed by the pressure factor gradient of source rock, the migration distance can be expressed by the horizontal and vertical distances between trap and source, and the capillary resistance force in carrier beds can be expressed by the capillary pressure in trap reservoirs. From the statistics of 62 stratigraphic reservoirs, oil-bearing height is in positive correlation with pressure factor gradient and dip angle of carrier bed and in negative correlation with horizontal and vertical distances between trap and source and capillary resistance force. On the basis of relations analysis between oil-bearing height and single factors, the multi-parameter match expression for the stratigraphic reservoir oil-bearing height has been established through multiple regressions. The application results show that the predicted value from match expression matches well with the true value. The expression can be used for the prediction of oil-bearing height of Tertiary stratigraphic reservoirs in Jiyang Depression. 摘要: 济阳坳陷第三系油藏总体上具有埋藏浅、圈源距离远、含油高度低、原油物性较差等特点。油藏含油高度主要受控于烃源岩排烃量、运移距离、输导层倾角、输导层毛细管阻力等4大因素。其中, 烃源岩排烃量可用烃源岩压力系数梯度、运移距离可用圈源平面距离和圈源埋深差、输导层毛细管阻力可用圈闭储集层毛细管压力等参数进行表征。从62个地层油藏统计结果来看, 含油高度与烃源岩压力系数梯度、输导层倾角呈较好正相关关系, 而与圈源平面距离、圈源埋深差、储集层毛细管压力等呈较明显负相关关系。在含油高度与单因素关系分析基础上, 通过多元回归, 建立起了地层油藏含油高度多参数拟合关系式。应用结果表明, 该拟合关系式预测值与实际值吻合度较高, 可用来对济阳坳陷第三系油藏含油高度进行定量预测。 Key words: stratigraphic reservoir, oil-bearing height, control factor, quantitative prediction, Jiyang Depression