The Resistivity Logging Response through Casing of Nine-Layer Formations with Crude Oil

Abstract

Because difference of formation model affects the potential distribution on the metal casing, the resistivity logging response can be obtained through casing by measuring the potentials on the metal casing. In fact, the logging responses are the comprehension effects of complex formation with Crude oil and metal casing, so that in the coefficients of transmission line equation (TLE), we should consider the effects of formation with Crude oil model in radial-direction. In the following, for the formation with Crude oil taking on nine --layer in axial-direction, and step in radial-direction, the resistivity logging responses through casing are researched and discussed, and given the recurrence formula with Crude oil to compute potential. Draw the curve of the resistivity logging response through casing of nine-layer formations with Crude oil. The conductivity of formation is computed is very approximating to that of formation with Crude oil model. The computing examples also show that this method has a fast computing speed (the run time of computing example is less than 1s). For analysis the logging response of nine-layers and block formations with Crude oil, and the design of logging instruments, the research is important significance and useful.