Induction Logging Through Casing by Detecting Lateral Waves: A Numerical Analysis.

Induction logging through casing (ILTC) is of significant importance to the evaluation of residual oils. Traditional induction logging fails to work in cased wells due to the shielding effect of metallic casings. To date, the feasibility of ILTC remains an open question. In this article, we propose an ILTC based on the detection of lateral waves that carry the formation information. Based on the analytical equations derived to describe the hybrid modes of total magnetic fields that can be detected inside cased wells, numerical analyses aiming to describe the behavior of lateral waves were carried out in both frequency and time domains. The obtained results comply with full-wave simulations and existing scaled experiments. Our results indicate that if an ILTC tool can be properly configured to work in a region dominated by lateral waves, and the casing effect and the primary field of the lateral waves can be effectively compensated, it is feasible to implement an ILTC to detect formation conductivities ranging from 0.01 to 5 S/m. [ABSTRACT FROM AUTHOR]