储层电各向异性模型的瞬变电磁响应

The Transient Electromagnetic Responsein of Electrical Anisotropic Reservoir Model

采用数字滤波算法对储层电各向异性模型的瞬变电磁响应进行数值模拟,首先在频率域计算出各向异性模型的电场响应,然后利用正弦变换将计算结果转换到时间域。通过对电偶极子源激发下的层状各向异性模型的瞬变电磁场进行计算,结果表明:对薄互层模型而言,当中间薄层为高阻时,视电阻率曲线在晚期随各向异性系数的增大而抬升,且各向异性的影响大于厚度的影响。当中间薄层为低阻时,各向异性系数对视电阻率曲线无影响。这对指导瞬变电磁对油藏勘探具有重要意义。

The transient electromagnetic response is formulated with digital filtering algorithm in electrical anisotropic reservoir model.The response of electric field is calculated first in frequency domain and the result obtained is transformed to time domain by sine transform.Through simulating the transient electromagnetic of an electric dipole in layered anisotropic model.For thin inter-bed model,the result shows that the curve of apparent resistivity is uplifted along with anisotropic coefficient increasing in late time when the middle thin layer is a high resistivity,and the effect of apparent resistivity is that anisotropic coefficient is greater than the thickness.When the middle thin layer is a low resistivity,the curve of apparent resistivity has no change.And it is significant for guiding the reservoir exploration.