各向异性倾斜地层双侧向测井响应数值模拟

利用三维有限元法,模拟了电性各向异性倾斜沉积岩层的双侧向测井响应。模拟结果表明:双侧向测井响应不仅受到地层倾角的影响,而且还受到地层电性各向异性的影响。在水平地层条件下,双侧向测井响应主要受到层理方向上地层电阻率的影响;在倾斜地层条件下,垂向上的地层电阻率对测井响应的影响增大。电性各向异性倾斜地层不仅造成电阻率曲线形态的变化,而且深、浅电阻率幅度差异更为复杂,给利用深、浅电阻率幅度差异定性识别油气层造成困难。

Numerical simulation of dual laterolog response in tilted anisotropic formation

The response of dual laterolog in tilted anisotropic sedimentary formation was simulated with the three-dimensional finite element method. The simulation shows that the log response is influenced by formation dip and formation anisotropy. The response of electronic log mainly reflects the resistivity of formation in the bedding direction in horizonal formation. However, the influence of vertical resistivity of formation becomes more significant in tilted formation. In the case of a tilted anisotropic formation, the resistivity log shape is quite different from that usually found in the vertical and isotropic formation. In addition, the resistivity difference between deep and shallow laterolog becomes complex and unreliable for identifying the pay zone.