Downhole Microseismic Monitoring Using Time-Division Multiplexed Fiber-Optic Accelerometer Array
| Autor: | Hailong Lu, Bin Xie, Duo Yi, Lijuan Gu, Shangran Xie, Yong Pan, Xiangge He, Xian Zhou, Zhangyuan Chen, Fei Liu, Yang Yuting, Min Zhang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Microseism
General Computer Science Dynamic range Fiber-optic accelerometer Acoustics General Engineering Geophone seismic sensor 010502 geochemistry & geophysics Accelerometer 01 natural sciences Noise (electronics) 010309 optics Acceleration Sensor array 0103 physical sciences General Materials Science Sensitivity (control systems) microseismic monitoring lcsh:Electrical engineering. Electronics. Nuclear engineering time-division multiplexing lcsh:TK1-9971 Geology 0105 earth and related environmental sciences |
| Zdroj: | IEEE Access, Vol 8, Pp 120104-120113 (2020) |
| ISSN: | 2169-3536 |
| Popis: | Microseismic monitoring is of importance for several geoscience research aspects and for applications in oil and gas industry. For signals generated by the ultra-weak microseismic events, conventional moving-coil geophone systems have reached their limit in detection sensitivity especially at high frequency range. Here we for the first time present a specially tailored fiber-optic sensing system targeting at downhole microseismic monitoring. The system contains 30 individual interferometric accelerometers and 2 reference sensors, which are time-division multiplexed into a 12-level vector seismic sensor array. The multiplexed accelerometers can achieve ~50 ng/ $\sqrt {\mathrm{Hz}} $ noise equivalent acceleration, which is superior to the commercial available moving-coil geophone systems at frequencies above 200 Hz. The measured sensitivity of the accelerometers can reach ~200 rad/g from 10 Hz to 1 kHz. The dynamic range is above 134 dB over the same frequency range and is higher than its electronic counterpart in the low frequency band. Moreover, the sensors can function properly under the harsh condition of 120 °C temperature and 40 MPa pressure over the 4-hour test duration. The sensor array along with the interrogator has been running uninterruptedly over 3 weeks in a multi-stage hydraulic fracturing stimulation field test. On-site results show that our system can clearly resolve the vector nature of both compressional and shear waves generated by the microseismic events. |
| Databáze: | OpenAIRE |
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