Directional drilling (or slant drilling) is the practice of drilling non-vertical . It can be broken down into four main groups: directional drilling, utility installation directional drilling, (horizontal directional drilling - HDD), and surface in seam (SIS), which horizontally intersects a vertical bore target to extract . Horizontal directional drilling bores underneath obstacles with a guided bit. The operator steers the bore head utilizing an angled pipe, pressurized fluids, and a steering tool that provides depth and positioning feedback.
[pdf] Wells are drilled directionally for several purposes: • Increasing the exposed section length through the reservoir by drilling through the reservoir at an angle.• Drilling into the reservoir where vertical access is difficult or not possible. For instance an oilfield under a town, under a lake, or underneath a difficult-to-drill formation.
[pdf] A drilling rig is an integrated system that , such as oil or water wells, or holes for and other construction purposes, into the earth's subsurface. Drilling rigs can be massive structures housing equipment used to drill , , or natural gas extraction wells, or they can be small enough to be moved manually by one person and such are called . Drilling rigs can s.
[pdf] 
