The Design And Research On Wireless Transmission System Of Real-time Monitoring For Formation Testing

Formation testing is a method to test the target strata and obtain the data of pressure and temperature in the process of drilling and oil production.The formation testing provides the basis for determining the underground measures and development plans,and it is a necessary mean for the exploration and development of oil fields.Due to the restrictions of shut-down valve and other mechanical mechanisms,the conventional formation testing method is not effective and real-time monitoring of underground conditions.To this end,real-time monitoring of formation testing will be realized with the method of cable transmission technology and wireless transmission technology.This paper will study the wireless transmission system of the real time monitoring system.This paper describes the basic working principle of the wireless electromagnetic transmission system and proposes wireless transmission of formation testing circuit design program.According to the requirement,the temperature and pressure data acquisition system is designed based on PIC18F4520.According to the transmission characteristics of electromagnetic induction channel,2FSK is used to achieve signal wireless transmission,modulation circuit based on direct digital frequency synthesis(DDS)and demodulation circuit based on phase locked loop(PLL)is designed,and the demodulation function is simulated based on Multisim Simulation and the related hardware functions are realized.The ground simulation test platform is established in the laboratory,and the feasibility of electromagnetic induction transmission is analyzed,which provides theoretical support for the hardware realization.