井下光纤微地震监测系统设计及应用

Design and application of microseismic monitoring system of underground optical fiber

为满足油气开发中微地震监测的需求,基于时分复用方案设计了一种新型井下3分量光纤微地震监测系统。结合室内测试,该系统本底噪声小于−101 dB,动态范围大于120 dB,级间串扰小于−67 dB,满足微地震信号探测的需求。该系统已成功应用于新疆油田水力压裂微地震现场探测。监测结果表明:该系统可清晰捕捉微地震的P波、S波信号,较好地揭示了水力压裂微地震信号的特征信息,为微地震事件的空间定位和裂缝特征参数解释建立了良好基础。

In order to meet the demand of microseismic monitoring in oil and gas development,a new type of underground three components optical fiber microseismic monitoring system was designed based on time-division multiplexing scheme.Combined with indoor test,the background noise of the system was less than−101 dB,dynamic range more than 120 dB,interstage crosstalk less than−67 dB,which meet the needs of microseismic signal detection.The system was successfully applied to the field detection of hydraulic fracturing microseism in Xinjiang Oilfield.The monitoring results show that the system can clearly capture the P-wave and S-wave signals of microseism,better reveal the characteristic information of hydraulic fracturing microseismic signals,and establish a good foundation for the spatial location of microseismic events and the interpretation of fracture characteristic parameters.