The Experimental Research On The Non-contact Method Of Through Casing Resistivity Logging

In our country,the oil harvesting efficiency is only about 30% to 40%,so there is a large proportion of crude oil distributed in the underground soil in the form of remaining oil.The cross-well is the remaining main area,and the resistivity of the casing formation is an important parameter to evaluate the distribution of residual oil.How to measure the resistivity by passing through a metal casing well and improve the residual oil recovery is the main trend in the current well logging research.In view of the problems of the traditional contact type three electrode log,such as the influence of casing deformation,the slow mechanical transmission time and the expensive fraud,the purpose of this paper is to research a kind of non-contact casing formation resistivity measurement methods.This thesis first introduces the current development of casing resistivity logging and analyzes the significance of the non-contact casing resistivity measurement.Then,based on the Maxwell equations,the theory of the non-contact casing resistivity measurement is described in detail,and the influence of the transmitting frequency,the distance between the wells and the casing parameters on the induced electromotive force in the receiving coil is studied by using the Comsol electromagnetic simulation software.Finally,an experimental simulation device is built,and the simulation results are verified by simulation experiments.In addition,the overall design of the prototype of the non-contact casing logging tool is completed.This study can lay a solid foundation for parameter optimization of non-contact cased formation logging tools.