Numerical Simulation and Application of Response Characteristics of High-Frequency Dielectric Logging Instrument

Complex reservoirs such as fresh-water formations and water-flooded reservoirs developed by water injection have complex electrical characteristics owing to the influence of formation water salinity. It is difficult to accurately evaluate and identify the fluid in such complex reservoirs by using the conventional resistivity method. However, the water salinity of the formation has a reduced effect on its dielectric constant; therefore, dielectric logging technology can be used to effectively identify freshwater formation and evaluate the water-floo ding level of the water-flooded layer. The accuracy of the formation response inversion charts of dielectric logging instruments is important for accurately evaluating fluids in complex reservoirs when these instruments are used. This study proposes a full-wave simulation method based on Maxwell's equations and the engineering parameters value of the dielectric logging instrument. The formation response conversion charts of the dielectric logging instrument are accurately calculated and can be used in practical logging; the simulation results are compared with those obtained using an equivalent magnetic dipole model. Based on the accurate simulation of the formation response of the dielectric logging instrument, a high-frequency dielectric logging instrument is developed, and it is applied to the fresh-water formation and water-flooded layer in the Nanyang and Ordos Basins.