Response Mechanism of Multi-frequency Micro-Resistivity Imaging Logging in Oil-Based Drilling Fluid Based on Numerical Simulation

The high resistivity characteristic of oil-based drilling fluid limits the application of micro-resistivity imaging logging in traditional water-based drilling fluid. At present, the micro-resistivity imaging logging technology of oil-base drilling fluid is one of the research hotspots in the logging field. There are four key difficulties in the research. First, the resistivity of the oil-based drilling fluid and the mud cake attached to the well wall is very high, so it is difficult to collect the micro measurement current signal. Secondly, oil-based drilling fluid and mud cake cover the geological characteristics, especially in the low resistivity formation, and it is difficult to characterize the change of formation properties. Third, under the excitation of high frequency signals, the capacitive coupling effect in higher resistivity formation hinders the characterization of geological features. Fourth, under the excitation of multi-frequency signals, the formation dielectric dispersion phenomenon further disturbs the extraction of formation parameters. Therefore, based on the numerical simulation, the response mechanism analysis of the multi-frequency micro-resistivity imaging logging of oil-base drilling fluid is studied for the above four aspects, and the innovative breakthrough methods and technologies should be adopted to develop the logging technology are further expounded. This study is of great significance to the development and application of multi-frequency micro-resistivity imaging logging technology for oil-based drilling fluid.