Design of positive pulse measurement while drilling system for mine rotary valve mud

Abstract

Abstract For the drilling of directional wells and horizontal wells, to ensure that the drilling trajectory is drilled in the coal seam in the direction designed before drilling, it is necessary to transmit information without interrupting the drilling process. The drilling fluid pressure pulse is divided into positive pulse, negative pulse, and continuous wave. The positive pulse transmission system with the mechanical structure of the lifting valve is widely used because of its high pulse signal strength and long propagation distance, which can be used in deep wells. With the increase of the information measured in the formation, the lifting valve can not meet the needs of the current information transmission due to the linear motion of the mechanical structure and the low transmission rate. The rotary valve as the pressure signal generation source can improve the pulse generation rate. Therefore, this paper analyzes the working principle and signal generation principle of the rotary valve positive pulse system, and collects the directional data and natural gamma value of the field test.