低频压力脉冲波在低渗储层中传播的一维改进模型的设计

Design of Improved 1-D Model for Low-frequency Pressure Pulse Wave Transmission in the Low Permeability Reservoir

低频压力脉冲在油层中传播时,能量是不断衰减的,直到衰减为零。低频压力脉冲的驱油增产作用主要是通过增加脉冲波动的有效作用距离实现的,因此,研究低频压力脉冲在油层中传播衰减规律是很有必要的。先由理论推导得出传播规律的数学表达式,再利用软件进行拟合得出传播规律。由comsol软件建立的低频压力脉冲波在油层中的一维传播改进模型,得到低频压力脉冲作用于油层后,油层的渗透率对波动传播的影响很大,在油相粘度、脉冲频率等其它参数不变的情况下,油层的渗透率越大,脉冲振幅的衰减越慢,传播的距离越远,有效作用距离越大。脉冲的频率对波动传播的影响也很大,脉冲频率越大,低频压力脉冲在油层中传播的衰减速度越快,脉冲波的有效作用距离越短。

When the low-frequency pressure pulse wave transmits in the oil layer, its energy will keep decreasing till zero. The low-frequency pressure pulse can increase the production by the pulse wave. It is essential to research the attenuation rule of the low-frequency pressure pulse wave in the oil layer. In this paper, mathematical expression of propagation law was firstly obtained by theoretical derivation, and then propagation law was obtained by software. With the help of comsol software, the improved 1-D model for the low-frequency pressure pulse wave transmission in the oil layer was established. And it was found that the permeability of the oil lay had huge influence on the transmission of the pulse wave when the other parameters, such as the oil viscosity and the pulse frequency, did not change. The greater the permeability of oil layer was, the further the pulse transmitted. The frequency of the pulse had huge influence the transmission, too. The greater the pulse frequency was, the faster the low frequency pulse decay rate in the oil layer was, and the shorter the distance of pulse wave transmitted.