Analysis of Signal Attenuation of Continuous （分析连续的信号衰减）.pdf

Research Journal of Applied Sciences, Engineering and Technology 5(15): 4018-4022, 2013 ISSN: 2040-7459; e-ISSN: 2040-7467 © Maxwell Scientific Organization, 2013 Submitted: December 08, 2012 Accepted: January 11, 2013 Published: April 25, 2013 Analysis of Signal Attenuation of Continuous Wave in Drill String Peng Jia, Deli Gao and Jun Fang Key laboratory for Petroleum Engineering of the Ministry of Education, China University of Petroleum, Beijing 102249, P.R. China Abstract: In this study, the friction model in non-Newtonian drilling fluid is developed to evaluate the signal attenuation in the information transmission with the continuous wave. A model of transient non-Newtonian power- law pipe flow is developed by assuming a steady viscosity varied only with the radius and the solution is derived analytically in complex domain and time domain. The frequency-dependent friction is developed based on the solution in the time domain and is used in the pressure wave transmission. And the analysis results show that the highest pressure amplification with resonant frequency increases with the power-law index n increase and the resonant frequency increases with the n decrease. Keywords: Continuous wave, frequency-dependent friction, non-Newtonian, propagation constant INTRODUCTION pressure wave transmitted in the non-Newtonian fluid flowing. In this study, the frequency-dependent Mud pulse telemetry has been the global standard attenuation model for the non-Newtonian power-law for real tim