Research On Collision Avoidance Method Of Cluster Well Based On Electromagnetic Induction

Cluster wells have many advantages in terms of relatively convenient management and high economic efficiency in many wells of complex structural wells.However,it is a systematic project.Any mistake in one part will cause a drilling accident.Therefore,how to avoid the occurrence of a wellbore collision accident is very important for the development of cluster wells.Due to the traditional imminent-well distance scanning technology and error analysis theory are not mature at the present stage,it is difficult to meet the accuracy requirements of the actual project;commonly used detection tools at home and abroad need to enter the equipment in the adjacent well,increasing the collision risk and the overall cost.Therefore,it is of great significance to study the proximity-range electromagnetic detection technology of cluster wells and improve the accuracy of electromagnetic detection for the independent innovation of well logging technology in China and to break the status quo of foreign technology monopoly.This paper explores a new approach for drilling-by-drilling anti-collision positioning in cluster wells where both magnetic excitation and magnetic reception are located in the well being drilled.First,a pair of magnetic sources with near-bit compensation at the near bit is used to magnetize the casing of the adjacent well and use the probe in the well to measure the magnetizing magnetic field of the casing to determine the distance and azimuth of the adjacent well.Secondly,based on the theory of magnetic dipoles,the distribution law of the magnetic field around the magnetic source and the distribution law of the magnetic field after the adjacent well casing is magnetized are explored,and the distance location formula of the adjacent well is deduced.Then,the influence of parameters such as the magnetic moment of the magnetic source,the parameters of the casing,and the distance and angle between the well being drilled and the neighboring well was investigated by numerical simulation.Finally,an outdoor simulation device was constructed,and the correctness and feasibility of the proposed positioning method were verified through experiments,which provided the theoretical basis and technical support for the development of the instrument.