Down-hole Seismic Survey System with Fiber-optic Accelerometer Sensor for 3-Dimensions Vertical Seismic Profile
3维VSP光纤检波器井下地震采集系统

A down-hole seismic survey system that can be applied in three dimensions vertical seismic profile (VSP) detection in petroleum exploration is demonstrated. The results of experiments show that the system has a dynamic measurement range of 80dB (ratio of maximum to minimum value) and the total delay for signal collection,process and communication is less than 200ms @ 2k bit sample rates. An array consisting of six fiber-optic accelerometers (receivers) is applied in this system. Each receiver is comprised of three fiber-optic Michelson interferometers. High-speed DSP chips are employed to realize the PGC demodulation and other algorithms to obtain the seismic information. Multi-ARM CPUs are introduced into the system to design the fiber-optic accelerometer array controller and the receiver array local bus. The design and experiments of the system are given in this paper in detail.