第1章 致密砂岩油藏考虑非线性弯曲段的数值模拟研究

致密砂岩油藏非线性渗流特征显著。但是目前的非线性渗流数学模型和数值模拟方法没有反映非线性弯曲段对油田生产的影响,导致产能预测精度差。因此,本文基于非线性弯曲段的表征方法以及考虑非线性渗流特征的相对渗透率计算方法,建立了三维三相非线性渗流数学模型,并研制了相应的数值模拟模块。通过研究发现,渗透率损失主要集中在距离井较远的油藏中部；非线性模型和拟启动压力梯度模型的初期产能相等,均小于常规模型。对于渗透率相同的大庆和长庆致密砂岩油藏,由于大庆致密砂岩油藏的喉道分布范围更窄,导致开发过程中大庆油田的渗透率损失更大,因此开发效果更差。

Numerical Simulation in tight sandstone oil reservoirs accounting for non-linear flow characters

Non-linear flow characters are greatly obvious in tight sandstone oil reservoirs. However, existing non-linear mathematical models and numerical simulations do not account for the effect of curve segment on field performance. Therefore, a new three-dimensional and two-phase non-linear flow mathematical model is built and a new numerical simulation is developed based on the method to characterize the non-linear flow characteristics and to calculate the relative permeability with non-linear flow characteristics in this paper. It is found that permeability reduction focuses on the middle of the reservoirs affected by the non-linear flow characters. Because the throat distribution of Daqing tight sandstone oil reservoirs is narrower than that of Changqing with the same permeability, permeability reduction of Daqing field is larger and sweep range is smaller. Therefore, oil productivity of Daqing is lower.