南黄海地震监测台网CSDP-2孔扩孔改造技术

Reaming technology for CSDP-2 hole of South Yellow Sea Earthquake Monitoring Network

对南黄海大陆架科学钻探CSDP-2孔进行扩孔改造,开展海洋深部地震监测,是“一带一路”地震监测台网建设的重要组成部分。通过对CSDP-2孔扩孔改造所采用的钻探工艺进行总结,摸索出了一套适合海上深部钻探的工艺技术:在钻井平台上选用转盘水井钻机,做到设备模块化、便携化;随钻测斜仪定向钻进技术能有效节省钻孔单点测斜校对时间,提高钻孔施工质量;配制海水低固相聚合物冲洗液体系,有效解决钻孔水敏性泥岩吸水膨胀及分散造浆、破碎地层漏失、含气地层有害气体溢出等难题,避免了孔内事故的发生。研究结果为后续海洋深部钻探提供了技术支撑。

It is an important part of the construction of the“Belt and Road”seismic monitoring network to carry out reaming and upgrading of CSDP-2 hole of the“Deep Marine Seismic Monitoring Network”.By summarizing the drilling process used for reaming CSDP-2 hole in the South Yellow Sea,a set of drilling technology suitable for offshore deep drilling has been developed:including rotary water well drilling rig which was used on the drilling platform to make the equipment modular and portable;Mud pulse MWD which can effectively save survey time and improve drilling quality from the single point inclinometer.Seawater based low solid polymer drilling fluid which has effectively tackled the problems such as mudstone expansion and mud production in water sensitive formation,circulation loss in broken formation,hazard gas emission from gas bearing formation so as to prevent downhole incidents.The research results can provide technical support and reference for subsequent deep ocean drilling.