汶川地震断裂带科学钻探一号孔（WFSD-1）钻探施工概况

Overview on Drilling Operation of the WFSD-1 in Wenchuan Earthquake Fault Scientific Drilling Project

摘要:

介绍了汶川地震断裂带科学钻探一号孔(WFSD-1)的施工情况以及取得的经验和教训。在施工中，克服了钻孔涌水、垮塌和地层极为破碎等困难。采用低失水、高密度和具有良好润滑性能的泥浆体系，解决了由地应力导致断层泥膨胀和缩径的技术难题。采用半合管取心技术，在破碎地层中也能获取原状性好的岩心。

Abstract:

This paper introduces the drilling operation of the WFSD-1 of the Wenchuan earthquake fault scientific drilling (WFSD) project as well as the experience gained and lessons learned during the hole drilling. Some extreme technical difficulties in the drilling operation, such as hole gushing water, broken formation, borehole collapse and tight hole, were overcome. A mud system with low water loss, high density and good lubrication properties was put to use to resolve mud expansion in fault gouge and diameter shrinkage resulted by geostatic stress. A twohaves tube coring technique was used to remain core in undisturbed state even in broken formation.