Numerical simulation of resistivity LWD tool based on higher-order vector finite element

Abstract

Numerical simulation of resistivity logging-while-drilling (LWD) tool response in complex borehole environments is of great importance for interpretation of measurement data and characterization of oil reservoirs. The simulation results can provide important theoretical guidance for designing novel electrical logging instruments and interpreting real-time logging data. In this paper, higher-order vector finite element method had been used to investigate the resistivity LWD tool response by changing coils spacing, transmitting frequency and structure of antenna system in the anisotropic formation. Numerical simulation results indicate that the change of T–R 1 spacing is an obvious influence on the investigation depth and detecting precision of the resistivity LWD tool, and the change of R 1–R 2 spacing can affect the resolution of the thin-layer distinguish. The change of transmitting frequency can improve the resolution of low-resistivity formation and high-resistivity formation of resistivity LWD tool. The change of the structure of the antenna system can provide accurate geosteering drilling information to directional resistivity LWD tool. Simulation results also indicated that the higher-order vector finite element method has good convergence speed and calculation accuracy and it is suitable to simulate the response of resistivity LWD tools.