井下微地震监测技术在页岩气“井工厂”压裂中的应用

摘要

Downhole microseismic monitoring technology can help determine the hydraulic fracture propagation direction,length and formation crack energy during shale gas well hydraulic fracturing,and thus can guide the adjustment of real-time fracturing operations and increase the fracturing volume.There-fore,downhole microseismic monitoring technology has been applied to the hydraulic fracturing operation in shale gas “well factory”on five pads of Block Wei 202 to detect fractures.The basic measurement prin-ciple of downhole microseismic monitoring technology was applied to the six wells on the platform A of Block Wei 202.The results function as a useful case study and an example,and both the mechanism and effect of the technology are evaluated in detail.The technique proved effective in identifying potential natu-ral fractures in the formation,monitoring the effect of temporary plugging and diverting volume fractu-ring,and guiding perforation parameter optimization.Studies and applications showed that the downhole microseismic monitoring technology could increase the shale gas reservoir reconstruction volume,and even out the reservoir reconstruction degree,thus playing an important role in cost-effective development of shale gas.%通过井下微地震监测可以获得页岩气井压裂过程中水力裂缝的展布方向、波及长度和地层破裂能量，从而指导压裂方案的实时调整，增大压裂改造体积。为此，威202井区5个平台进行页岩气“井工厂”压裂施工时，应用井下微地震监测技术进行了裂缝监测。在介绍井下微地震监测技术基本测量原理的基础上，以威202井区 A平台6口井的应用为例，详细介绍了该技术在有效识别地层中潜在天然裂缝、监测暂堵转向体积压裂效果、指导射孔参数优化等方面的机理与效果。研究表明，应用井下微地震监测技术可以增大页岩气储层改造体积，提高储层均匀改造程度，这对于页岩气的经济有效开发具有重要作用。