出典:Wikipedia
出典:『Wikipedia』 (2011/08/02 16:00 UTC 版)
Directional drilling (or slant drilling) is the practice of drilling non-vertical wells. It can be broken down into three main groups: Oilfield Directional Drilling, Utility Installation Directional Drilling (or H.D.D. or Horizontal Directional Drilling) Directional boring, and in-seam directional drilling (Coal-Bed methane).