威荣气田深层页岩气压裂井中微地震监测技术
Downhole Microseismic Monitoring Technology for Hydraulic Fracturing in Deep Shale Gas Wells in WeiRong Gas Field

井中微地震监测技术是目前诊断评价页岩气体积压裂的最有效技术手段，在页岩气田开发过程中发挥着重要作用。威荣深层页岩气田储层埋藏深度3500~3850米，目的层地温最高达140℃以上，在页岩气井水力压裂的整个过程中，耐高温且能够持续长时间稳定工作的三分量检波器成为了威荣气田页岩气井体积压裂监测的主要技术难题。通过研制自主知识产权的高温井下微地震监测仪，仪器在井下138℃条件下长时间工作状态稳定，资料品质高，满足威荣地区高温监测要求，在1925米的最远有效监测空间距离上依然能够拾取明显的微地震事件特征信号。通过现场处理解释技术能够实时提供压裂缝网的空间几何参数扩展及动态变化，用于现场评估和指导压裂施工。通过压后精细解释技术，可获取压裂缝网展布特征，进行压裂体积计算，暂堵效果分析、压裂缝与天然裂缝发育特征及关系研究、套管变形预警分析等研究工作。已在威荣气田威页3X平台、4X平台、4Y平台完成了10口井70余层段的水力压裂监测，为压裂施工效果评估、后续压裂设计调整、开发方案优化及井距调整等工作提供了技术参考。
Borehole microseismic monitoring technology is the most effective technical mean to diagnose and evaluate shale gas volume fracturing, which plays an important role in the development of shale gas field. The buried depth of WeiRong deep shale gas field is 3500~3850 m, and the ground temperature of the target layer is up to 140？C. In the whole process of hydraulic fracturing ofshale gas wells, three-component geophones that are resistant to high temperature and can workstably for a long time have become the main technical problem of volume fracturing monitoring ofshale gas wells in Weirong Gas Field. Through the development of high temperature underground microseismic monitoring instrument with independent intellectual property rights, the instrument works stably for a long time under the condition of 138？C underground, with high data quality, meeting the requirements of high temperature monitoring in WeiRong area, and can still pick up obvious characteristic signals of microseismic events at the farthest effective monitoring space distance of 1925 m. The field data processing and interpretation technology can provide real-time expansion and dynamic change of space geometric parameters of hydraulic fracture network, which can be used for field evaluation and guidance of hydraulic fracture operation. Through the fine interpretation technology after hydraulic fracturing, the distribution characteristics of fracture network can be obtained, and the fracturing volume calculation, temporary plugging effect analysis, development characteristics and relationship between hydraulic fractures and natural fractures, early warning analysis of casing deformation and other research work can be carried out. The microseismic monitoring of more than 70 layers in 10 wells has been completed in Weiye-3X platform, -4X platform and -4Y platform of WeiRong gas field, which provides technical reference for hydraulic fracturing evaluation, subsequent fracturing design adjustment, gas field development scheme optimization and well spacing adjustment.