Directional drilling technologies for Wanfu River crossing works of Sichuan-to-East Gas Transmission pipeline
XU Xue-cai · Yangtze River · 2010
In case of the special topography inconvenient for excavation in the installation of long-distance pipeline,such as rivers,ponds and buildings,the construction quantities can be reduced and construction period can be shortened by the adoption of directional drilling technologies.The technologies are applied in the construction of Wanfu River crossing works of Sichuan-to-East Gas Transmission pipeline.We introduce the technical measures of guiding-hole drilling,hole expanding in advance,hole washing and back dragging in directional drilling construction,and also elaborate the mixture,circulation and reclamation of slurry.The experiences and methods provide references for the directional drilling in poor geological conditions.