基于模板匹配技术的微地震事件检测在水平井立体开发井网中的应用

Application of micro-seismic event detection based on a template matching technique during horizontal well pattern development

2019年,新疆玛湖油田玛131井区首次在致密砾岩油藏中采用双井(水平井+直井)微地震监测的方式采集微地震数据,但采用传统的长短时窗比(STA/LTA)微地震事件检测算法在两个阵列上仅检测出少量的可对应微地震事件,无法开展双井同时定位和矩张量反演,也不能获得震源机制特征。为此,采用基于模板匹配技术的微地震事件检测对采集的微地震数据进行了重新处理,检测出了大量微地震事件,并开展了双井定位和矩张量反演应用分析,获得了微地震事件震源机制特征和破裂参数。结果表明:模板匹配算法可以在多井阵列中识别出更多的有效微地震事件,使矩张量反演成为可能;针对玛131井区天然裂缝不发育的致密砾岩储层,水力裂缝破裂具有多种走向,可形成复杂缝网;T_(1)b_(2)小层的单段最佳压裂液量在1700 m^(3)左右,T 1b 3小层的单段最佳压裂液量在820 m^(3)左右,进一步加大压裂规模对产量的贡献作用降低。

In 2019,micro-seismic data were collected for the first time in a tight conglomerate reservoir in the Ma 131 well area of the Xinjiang Mahu Oil Field using dual-well(horizontal well and vertical well)micro-seismic monitoring.However,only a small number of corresponding micro-seismic events were detected on both arrays using the traditional long-short time window ratio(STA/LTA)algorithm,which could neither carry out simultaneous dual-well localization and moment tensor inversion nor obtain the characteristics of the source mechanism.Therefore,the micro-seismic event detection based on the template matching technique was reprocessed.Many micro-seismic events were detected,and an analysis of dual-well localization and moment tensor inversion applications was performed to determine the characteristics of the source mechanism and rupture parameters of micro-seismic events.The results showed that the template matching algorithm can identify more valid micro-seismic events in a multi-well array,making moment tensor inversion possible.In the dense conglomerate reservoir of the Ma 131 well area,where natural fractures are not developed,hydraulic fractures have multiple orientations and can form a complex fracture network.The optimal fracturing fluid scale for a single section in T_(1)b_(2)and T 1b 3was approximately 1700 m^(3)and 820 m^(3),respectively,and the contribution of further increasing the fracturing scale to the production decreased.