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为了模拟油气二次运移过程中受重力和毛细管力控制的油流进入水饱和沙中,设计了比例物理模型。该模型提供了流动模式的可视性及油气运移速率和效率的评估。把模型的大小和物理性质设计得与地质系统中的重力、毛细管力和黏力平衡一样。物理模型是夹在两层玻璃板之间的一个沙层,沙层高 52cm,长 100cm,厚 2.5cm,并以 5°的倾角倾斜,孔隙度为 42%,渗透率为 7.0×10~(-10) m~2(710D)。它模拟了孔隙度为 20%,渗透率为 9.9×10~(-14)m~2(100mD),厚27m且覆盖在生油岩之上的一个地层上的输导层。染色的油以1cm~3/d的速率从最低的一角注入,在常压下从最高角流出,油的运动可直观跟踪,并用超声波速度测量仪测量。模型中流体的流动使我们得出了油在均质含水输导层中运移的结论。一个圈闭充油速率的分级变化不是二次运移速率,而是油从源岩中释放的速率。在垂向运移过程中,强烈的扩散可能导致油气大量损失(当输导层覆盖于源岩之上)。由于流体集中于顶部盖层之下,侧向运移过程中的损失可能较小。
In order to simulate the oil flow controlled by gravity and capillary force into the water saturated sand during the secondary migration of oil and gas, a proportional physical model was designed. The model provides visibility of flow patterns and assessment of hydrocarbon migration rates and efficiencies. The size and physical properties of the model are designed to be the same as the balance of gravity, capillary forces and viscous forces in the geological system. The physical model is a sand layer sandwiched between two glass panes. The sand layer is 52 cm high, 100 cm long and 2.5 cm thick and is inclined at an inclination of 5 °. The porosity is 42% and the permeability is 7.0 × 10 ~ -10) m ~ 2 (710D). It simulates a formation with a porosity of 20% and a permeability of 9.9 × 10 ~ (-14) m ~ 2 (100mD) and a thickness of 27m covering a formation above the source rock. The stained oil is injected from the lowest corner at a rate of 1 cm-3 / d and exits at the highest angle at atmospheric pressure. The oil movement is tracked visually and measured with an ultrasonic velocity meter. The flow of fluid in the model leads us to conclude that the oil migrates in a homogeneous aqueous bearing. The fractional change in oil-bearing rate of a trap is not the rate of secondary migration but rather the rate of oil release from the source rock. During vertical migration, strong diffusion can result in significant loss of oil and gas (when the transport layer overlies the source rock). As fluid is concentrated below the top cap, the loss during lateral migration may be small.