HR: 1340h
AN: S33A-0297    [Abstracts]
TI: Multi-frequency Array Acoustic Logging With Fiber Optic Cable Transmission System
AU: * LI, Y
EM: yanhual@email.arizona.edu
AF: Department of Hydrology and Water Resource,University of Arizona, Harshbarger Bldg.P.O.Box 210011, TUCSON, AZ 85721 United States
AU: Chu, Z
EM: chuzehan1939@sina.com
AF: China Petroleum University, Changping, Beijing, China, Beijing, 102249 China
AU: Peng, F
EM: pengf1982@163.com
AF: China Petroleum University, Changping, Beijing, China, Beijing, 102249 China
AU: Xu, L
EM: zh7818244@sina.com
AF: Crossbar Acoustic Optic Electric Tech. Company, Panjin, Liaoning, Panjin, 124010 China
AB: Multi-frequency array acoustic logging tool with fiber optic cable transmission system of 10M bit/s transmitting rate, together with practical logging results, are presented in this paper. Sonic signals of three frequencies----10 kHz, 20 kHz and 40 kHz are transmitted in downhole application of this tool. Receiving array includes two sets of receiver, with each set having 8 receivers. The acoustic properties of medium in different radial depth around the borehole can be detected by the measuring results of three different frequencies. It is found that the signal loss is less than 10dB for total transmitting system which includes fiber optic cable of 4250m in length, downhole electric-to-optic converting system (downhole optic transmitter and receiver), downhole cable head, fiber rotary joints in surface cable winch and surface optic-to-electric converting system (surface optic transmitter and receiver). At present, this tool is capable of transmitting all wavelet of three frequencies with transmitting rate of 1.25Mbit/s. Field test of this tool has been conducted successfully in simulated well of 550m in depth in Liaohe oilfield, China. Waveforms and interpretations are discussed in detail.
DE: 1794 Instruments and techniques
DE: 9805 Instruments useful in three or more fields
SC: Seismology [S]
MN: Fall Meeting 2005