Problems and developing direction of anti-collision technology in the dense well pattern area

Unexpected wellbore collision will bring potential or even catastrophic consequence to human beings and environment, the well-bore anti-collision technology is an effective approach to reduce this kind of accident, the function of which is specially important during the process of infill development drilling and multi-well drilling. Through the analysis of existing anti-collision technology, the conclusion can be gotten that the failure of well bore anti-collision is brought by 4 factors which include the big error of survey steering tool data,low accuracy, distortion or loss of adjacent wells’ trajectory parameters,the over-idealized pathfitting method and the defective scanning method for anti-collision.The causes of failure of anti-collision is the fitted path based on the low accuracy parameters and over-idealized path-fitting method cannot be equivalent to the actual ones,and the relative positions of distorted well trajectories cannot reflect the facts either.This paper discusses the development tendency of anticollision technology in the future and puts forward the concept of active anti-collision.The paper also lists programs which probably solve the anti-collision problem and provide the reference to the pertinent research.