大斜度井中利用交叉分量快速反演井斜角

利用三维感应测井交叉分量之差响应曲线在边界附近的响应行为,建立了求解大斜度井中井斜角快速反演方法.响应曲线随真实垂直深度(TVD)变化的对数衰减率与随测量距离(MD)变化的对数衰减率与之比是井斜角的余弦函数,通过简单三角函数计算可快速反演井斜角.响应曲线形态规则,在层状各向异性地层中与垂直电导率无关,主要反映水平电导率反差造成的地层边界信息.因此本文的井斜角快速反演方法既适用于各向同性地层也适用于各向异性地层.我们考察了测井环境及仪器参数对响应曲线衰减率的影响以及衰减率估算偏差对井斜角反演精度的影响.数值模拟结果验证了该反演方法在大斜度井中的有效性和实用性.

Fast inverse the relative dip using cross-component in highly deviated well

In this paper, we developed a fast inversion method to solve the relative dip by using the difference of cross-component of three-dimensional induction logging tool. The ratio between the logarithmic decay rates along the true vertical distance (TVD) and that along the measured depth (MD) is a cosine function about the relative dip. It can fast the inversion process of the relative dip through solving a simple trigonometric function. The difference of cross-component has regular response behavior and its amplitude is proportional to the difference of the horizontal conductivities of the adjacent layers. The response is also independent of the vertical conductivity. With this merit, our method can be applied to both isotropic and anisotropic formations. We examined the effects of borehole environment and tool parameters on the logarithmic decay rate and the logarithmic decay rate on the accuracy of the inversed relative dip. Numerical results validated that our method is practical and effective in highly deviated well.