Design Of Condition Monitoring System For Downhole Petroleum Instruments

Cableless over-drilling memory logging technology is a very effective logging technology in high-deviated wells,horizontal wells and complex wells and in harsh conditions.It is used widely in the field of logging.However,in the process of cableless over-drilling memory logging,the ground system cannot know the working condition of logging instrument before it is pumped out,which cause low logging success rate.Therefore,it is of important engineering significance to monitor the condition of logging instrument before it is pumped out.Aimed at an improved over-drilling memory logging technology,the system is designed to monitor the condition of logging instrument.The system includes ground system and the downhole system.The ground system sends control command transmitted to downhole system by cable.The instrument in the underground will send the instrument condition data to the ground system after receives the command,so realizing the condition monitoring of logging instrument.The system can monitor instrument condition before before it is pumped out.The main contents of this paper are as follows:(1)According to the characteristics of the improved over-drilling memory logging technology,the paper completes the overall scheme design of the logging instrument condition monitoring system.(2)The ground monitoring system is built with DSP processor TMS320F28069 of TI Company as the core,and the design of its peripheral modules was finished,including command drive module,gain control module,depth signal preprocessing module,cable tension preprocessing module and USB interface.Realizing the power amplification of condition monitoring command,the preprocessing of status data and bidirectional transmission of command and condition data between computer and ground monitoring circuit.(3)Combined with the hardware system,the control program design of the ground monitoring module is completed in the CCS platform,including USB interface program design,command coding program design,program control circuit program design,ADC module program design and eQEP module program design,which realize command code and data acquisition.(4)The computer control interface is designed in the Visual Studio platform,and the decoding algorithm of the state data is designed to realize the decoding of the state data.The test experiment of the system have been carried out,which include communication test experiment,state data timing acquisition experiment and grasper control experiment,the result shows that the system can realize the condition monitoring of logging instrument.