Research And Implementation On Embedded System For LWD Azimuthal Gamma Imaging

Since it can provide technical support for precise geological orientation,LWD(Logging While Drilling)azimuth gamma technology has been becoming a research hotspot in recent years at home and abroad.The purpose of this dissertation is to design a CPU-based embedded component,which is to collect and calculate LWD azimuthal gamma imaging data,cooperate with other components including mechanical component,communication component and ground units,so as to accomplish LWD azimuthal gamma imaging system.In the first step,this dissertation introduces the research state and engineering background of the LWD azimuth gamma well logging technology nowadays.The classic methods are analyzed,and then it is found that they are susceptible to vibration,temperature,mechanical structure and other factors,which provide novel ideas for our designs as follows.Electronic compass is selected to get tool face angle,and flexible accelerometer is selected to get angle of well inclination.Moreover,to satisfy the requirements of computing speed and sampling rate,ARM9 is employed as processor in processing unit and AD7671 is employed in acquisition unit.In the next step,considering its excellent latency performance,we choose ?C/OS-? as the operating system,and migrate it into the designed hardware system.Besides,three algorithms which are vital for the system are designed and realized as following: tool face angle finding algorithm basing on deviation compensation,the sensor fusion algorithm combining the gamma value and the azimuth information,the algorithm for dynamic angle of well inclination computing.Finally,through the system test,it is verified that the embedded system can collect and calculate the LWD azimuthal gamma imaging data in high efficiency,and has bright prospect in engineering application.