井中微震监测观测系统优化设计

Optimization Design of Borehole-based Microseismic Monitoring Geometry

数据采集是水力压裂微震监测技术的基础,其品质高低决定了微震监测的成败。合理设计观测系统有助于提高监测数据品质。使用模型数据和实际监测数据,分析了现有观测系统对微震事件的初至信息和极化特征两个重要参数的影响。提出对观测系统进行改进:加大检波器间距,单边布置检波器和安装临时桥塞器;以此弥补检波器有限的不足和注压流体对于微震事件信号的干扰,进而提升微震监测数据的品质,有利于提高微震震源定位精度。

Data acquisition is the basis of microseismic monitoring of hydraulic fracture.The success of monito-ring depends on the qulity of monitoring record.The reasonable design of monitoring geometry can improve the quli-ty of monitoring record.By using model and field record,it is illustrated that monitoring geometry has effect on first-arrival information and polarization of microseismic event.Some methods are proposed to optimize the monito-ring geometry design.The methods include increasing the space distance between geophones,keeping reasonable distance between geophone and fractured reservoir and installing bridge plug at the end of geophones to suppress the interference of fracturing noise.