Design And Development Of Mine-Used LWD Azimuthal Gamma Measurement Probe

The LWD technology is an important means to realize the geo-steering and real-time formation evaluation.With the increasing demand for coal mine safety,coal mine LWD technology has broad application prospects in the fine exploration of mining geological conditions and guided boring.Based on the actual working conditions,the low power,small size,strong anti-vibration and water resistance of the coal mine LWD must be satisfied.Gamma logging is one of the important components of coal mine LWD,and it is an important means to realize lithology judgment in the process of LWD.Azimuth gamma logging data contains formation azimuth information,which can be found in time to deviate from the direction,guide the drilling track adjustment,and effectively reduce the invalid drilling distance.Therefore,the thesis based on the actual application requirement of coal mine,designed and developed azimuth gamma parameter measurement probe of the coal mine LWD without cable.In the thesis,the distribution law of formation gamma rays,the measurement principle and the working mode of the mine-used LWD azimuthal gamma measurement probe are studied in depth;On the basis of theoretical research,the general design scheme of the probe is put forward,design and development of the azimuth gamma detector,pulse shaping and processing circuit,pulse counting and memory circuit,the probe intrinsically safe power supply and other unit circuit,and the development of pulse counting and control software;In view of the strong vibration,high water-pressure and little aperture special working environment,analyzed the influence of the probe reliability and stability of the interference source and characteristics,designing and processing corresponding mechanical components,taken the corresponding anti-interference measures.After the assembly and debugging completed MA certification,obtain the mining product safety certification mark and proof certificate and carried out the ground and underground coal mine site test,the results show that the technical index,explosion-proof performance of the probe meets the design requirements.The probe is stable and the measurement data is reliable,can meet the coal mine small diameter borehole LWD field applications.