DIRECTIONAL DRILLING SOLVES UNSTABLE SLOPE ALONG CANADIAN PIPELINE

R. P. Boivin, P. C. Cavanagh, R. G. Clarke NOVA Corp. of Alberta Calgary Directional drilling has been used to relocate two high-pressure gas pipelines operated by NOVA Corp.'s Alberta Gas Transmission below an unstable slope in a remote area of northeast Alberta (Fig. 1). Using directional drilling to place the pipelines below the failure zone was the least expensive, lowest risk option, compared to other alternatives considered. The failure zone had been satisfactorily delineated and