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模拟电阻率测井仪的响应,对一维效应,如径向效应(井眼和侵入)和轴向效应(薄层)的相互影响要有所了解。对于2MHz电磁波传播电阻率测井仪更是如此,因为其工作频率甚高,从而引起一维效应之间的相互影响。本文采用一种新的积分方程计算机程序来模拟2MHz电磁波传播电阻率测井仪在具有径向和轴向效应的地层中的响应。模拟的结果证明,对于几乎所有的目的层,振幅比测量值较相位差测量值具有更深的探测深度。然而,在被侵入的薄层中,振幅比曲线的垂向分辨率变差,从而引起两曲线的正常顺序颠倒(这种情况在中、深双感应测井中也可以看到)。此外,探测深度随着围岩电阻率的增大而加大。当存在薄层时,在对径向响应的模拟中,还可以看到负响应侵入带。斜坡侵入剖面示例与阶状侵入剖面示例的对比证明,当阶梯位于斜面的中心时,两种不同的模拟产生几乎相同的结果。
The response of a simulated resistivity tool is well-known for the interaction of one-dimensional effects such as radial effects (borehole and intrusion) and axial effects (laminae). This is especially true for 2 MHz EM wave resistivity tools, which operate at very high frequencies, causing a one-dimensional effect to interact with each other. In this paper, a new integral equation computer program is used to simulate the response of a 2MHz electromagnetic wave propagation resistivity tool in a formation with radial and axial effects. Simulation results show that the amplitude ratio measurement has a deeper detection depth than the phase difference measurement for almost all of the target layers. However, in the intruded thin layer, the vertical resolution of the amplitude ratio curve becomes worse, causing the normal order of the two curves to be reversed (as can be seen in medium and deep dual induction logs). In addition, the depth of investigation increases with the resistivity of the surrounding rock. Negative response invaded zone can also be seen in the simulation of radial response when a thin layer is present. A comparison of the ramp intrusion profile example with the stepped intrusion profile example demonstrates that the two different simulations produce nearly the same result when the step is in the center of the bevel.