Controlled directional drilling is the science of deviating a well bore along a planned course to a subsurface target whose location is a given lateral distance and direction from the vertical. At a specified vertical depth, this definition is the fundamental concept of controlled directional drilling even in a well bore which is held as close to vertical as possible as well as a deliberately planned deviation from the vertical.

Introduction

Rotary steerable

Positioning and Coordinate Systems

Bottom Hole Assembly

DD Tools