Numerical Simulation Of Well Electromagnetic Method

With the development of the national economy,the demand for petroleum,natural gas and various kinds of mineral resources is increasing day by day.The research on the theory of deep resource exploration method and the development of deep exploration instrument system attract much attention.Well to electromagnetic method is the use of wells to send high-power alternating current,the ground electromagnetic field response to electromagnetic exploration methods,the launch directly into the underground,to overcome the near-surface interference and shorten the distance between the launch source and the detection of the target,with exploration A wide range of exploration depth,high resolution advantages,deep exploration in areas such as resource has a wide range of applications.As a kind of high-precision exploration method applied to the well,this method was introduced from Russia in the 90's of last century.It conducted a series of experiments and applications in the oil field,delineating reservoirs,studying reservoir distribution,oil well injection or Grouting dynamic monitoring have achieved some results,become a groundwork of complex geoelectric model of a new type of technical methods.However,due to the particularity of the method and the three-dimensional characteristics of the problem,the key three-dimensional forward problem has not been effectively solved,leading to a serious lag in the interpretation of the well-to-ground electromagnetism method,which hinders the further application of the method.Three-dimensional numerical simulation of well electromagnetism is a hot issue in geophysical prospecting,which is the premise and foundation of three-dimensional inversion.Due to the poor convergence of 3D forward modeling and long computation time,it is still in the research stage.COMSOL MULTIPHYSICS software is a large-scale finite element method three-dimensional numerical simulation software.Based on this software,the author studies the conditions of its use,and uses the DC-well geoelectric method to simulate the electromagnetic field response in one-,twoand three-The related problems in well electromagnetism are studied.The validity and practicability of the wellbore electromagnetic method are verified,laying the foundation for further research work.In this paper,three-dimensional forward modeling of electromagnetic layered medium(uniform half-space)in well is studied by using AC / DC module in COMSOL MULTIPHYSICS software to verify the feasibility of electromagnetic simulation ofwell using this software.At the same time,the low resistance model and the high resistance model are simulated in the three-dimensional space.And the potential and current density contours and sections are plotted based on the result data.The comparison between the plane contour map and the literature verifies that the threeFeasibility of electromagnetic response.It also laid the foundation for the three-dimensional inversion of the electromagnetic well method.