Fault detection based on microseismic events
Fault detection based on microseismic events
复制标题
基于微震事件的故障检测
DOI：
10.1007/s11770-017-0631-z
复制
发表时间：
2017
影响因子：
0.7
通讯作者：
C. Yin
中科院分区：
文献类型：
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作者：
C. Yin
在非常规油气藏中，小断层允许石油和天然气流动，也是勘探的障碍;因为，（1）压裂促进流体运移，（2）储层水淹，（3）触发小地震。由于地震分辨率低，这些小断层通常无法检测到。然而，这样的小断层非常活跃，并且释放足够的能量以在水力压裂期间引发大量的微震事件（ME）。在这项研究中，我们确定微裂缝（MF）的水力压裂和天然小断层的基础上的微震活动特征，如时空分布，震源机制，大小，振幅和频率。首先，通过储层应力分析识别小断层和微地震的发生机制，并根据微地震震级标定微地震的最大能量。分析了天然断裂和MF触发的微地震的动力学特征（频率和振幅），并根据震源机制对天然断裂和MF的几何形态和活动类型进行了分类。最后，利用断层的时空分布、震级、震源机制、振幅、频率等特征的差异，对天然断裂和人工断裂进行了区分。
In unconventional reservoirs, small faults allow the flow of oil and gas as well as act as obstacles to exploration; for, (1) fracturing facilitates fluid migration, (2) reservoir flooding, and (3) triggering of small earthquakes. These small faults are not generally detected because of the low seismic resolution. However, such small faults are very active and release sufficient energy to initiate a large number of microseismic events (MEs) during hydraulic fracturing. In this study, we identified microfractures (MF) from hydraulic fracturing and natural small faults based on microseismicity characteristics, such as the time–space distribution, source mechanism, magnitude, amplitude, and frequency. First, I identified the mechanism of small faults and MF by reservoir stress analysis and calibrated the ME based on the microseismic magnitude. The dynamic characteristics (frequency and amplitude) of MEs triggered by natural faults and MF were analyzed; moreover, the geometry and activity types of natural fault and MF were grouped according to the source mechanism. Finally, the differences among time–space distribution, magnitude, source mechanism, amplitude, and frequency were used to differentiate natural faults and manmade fractures.