3D FDM Modeling of Acoustic Reflection Logging in a Deviated Well

Acoustic reflection image logging has become a potential long range detection method for geo-steering, particularly in the environment of horizontal and/or deviated wells during the development of shale gas plays. As the most common numerical tool used to study reflection image logging technology, Finite Difference Method (FDM) is a relatively efficient approach and can be easily applied to study complicated 3D cases. In this paper, we first describe the principle of the mathematical development and then present the modelling examples with this new method for the investigation of the acoustic reflection image logging responses in a deviated well. By integrating the C-PML and the M-PML, the accuracy and the stability of the FDM modelling can be both achieved at the same time through the optimization of the damping profile. The improved FDM algorithm can provide a powerful tool for studying the imaging method of the acoustic reflection logging in a deviated well by making a fuller use of the reflected waves of qP-qP and qSV-qSV in various offsets.