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我们现在对导致油气形成有经济价值的聚集的地球化学过程的理解,可以简化成简单的准则和公式,石油地质工作者就能在钻探之前用地球化学估计输送到圈闭中的油气体积和成分。在大多数沉积盆地中,油在120—150℃之间从油源岩中排出,而大多数气和凝析油在150—230℃之间释放。当油源岩的初期产量超过10kg/t时,油的排出效率为60—90%。排出的油和气以被流体位能梯度所驱动的富油相形式运移。在水平有效渗透率大于1md的地层中,油和气大多数沿倾向横着向上运移。在渗透率低的岩石中,石油流体沿着将它和高渗透横向运油层隔开的阻力最小的通道(即渗透性最好或最薄的地层)垂直向上或向下运移。留在运移通道内的石油的剩余饱和度与百分之几的孔隙度不相上下。油源岩的地球化学分析可帮助人们确定在石油远景区储油区中排出的石油流体的产量和组成。根据石油流体的相关系和密度,可将这些流体质量转换成体积。对可能运移石油的岩石总体积和构成运移通道的岩石的平均孔隙度进行估算,便有可能估算出运移损失。这些损失限制了石油流体离开成熟油源岩的运移范围和在远景区聚集的剩余石油的体积。
Our current understanding of the geochemical processes that lead to the accumulation of economically valuable aggregates of geo- gas can be simplified into simple rules and equations that geophysicalians can use to geochemically estimate the volume and composition of hydrocarbons transported to the trap before drilling . In most sedimentary basins, oil is drained from source rocks at 120-150 ° C while most gas and condensate are released between 150-230 ° C. When the initial production of oil source rocks exceeds 10 kg / t, the oil discharge efficiency is 60-90%. The discharged oil and gas are transported in the form of an oil-rich phase driven by the gradient of the fluid potential. In the formations where the horizontal effective permeability is greater than 1 md, most of oil and gas migrate laterally upward along the trend. In rocks with low permeability, the petroleum fluid moves vertically upward or downward along the channel (ie, the most permeable or the thinnest layer) that has the least resistance to separating it from the high permeability transversal reservoir. The residual saturation of oil remaining in the migration channel is comparable to a few percent of the porosity. The geochemical analysis of source rocks can help determine the yield and composition of petroleum fluids that are expelled from the reservoir in the petroleum foreground. Depending on the correlation and density of petroleum fluids, these fluid masses can be converted into volumes. Estimating the total volume of rocks that may have migrated oil and the average porosity of the rocks that make up the migration path makes it possible to estimate migration losses. These losses limit the extent to which petroleum fluids leave the mature source rocks and the volume of oil remaining in the foreground.