Study On The Theory And Method Of Relief Well Electromagnetic Detection

In recent years,blowouts of accidents cause environmental pollution problems,which have become increasingly serious.Scholars have paid much attention to the fast and efficient control methods of accident well.Relief well technology is one of the most effective ways to solve the blowout of accidents.The precise detection of posture,relative distance and azimuth between relief wells and accident wells has played a vital role for successful implementation of the relief well.In order to solve this problem,this paper focuses on down hole electromagnetic detection and localization of the relief well.This paper studies two electromagnetic detecting methods of relief well,which includes the current injection method and the transient electromagnetic method.It deduces the relationship between the relief well electromagnetic detection parameters and the response signals based on the max-well's equations.Then,it analyses the parameters changes of the current injection method,such as electrode layout,injection current size,casing pipe space of electrode and accident wells,casing pipe length,etc.To study the influence of the electromagnetic response signal of receiving coil,the paper analyzes the effects of the position of coils,the number of turns of coils,the size of the emission current,the spacing of coils and the accident well,It provides a theoretical basis for the electrode,coil and detection device optimization design.Secondly,this paper established the relief well electromagnetic detection positioning model of the injection current method and transient electromagnetic method.In order to obtain the certain distance and azimuth information between relief wells and accident wells,it carries out researches of location theories and inversion interpretation methods of the distance and orientation of accident well and the relief wellFinally,on the basis of a large amount of simulation test,it compares and analyzes the theoretical researches and simulation experiment results.Scale tests of orientation and distance can prove a conclusion that distance and azimuth information can be judged according to the magnetic field strength of the received signal.Field simulation experiments are developed to verify the feasibility of detection methods and detection devices of the relief wells and provide the necessary preparations for the subsequent large-scale application researches.