A General Overview of Air Drilling and Deviation Control

What is the most economical way to drill a well. It may be by using air, drilling fluids (other than air or gas), or a combination of both as the circulating medium. This decision requires a thorough study of an area before drilling. Regardless of the circulating medium used, crooked holes can be a problem. Similar methods are used to prevent crooked holes in air and fluid drilling, but some of the techniques differ. Selection of the proper bottomhole assembly will determine the economical success of drilling a well with either air or fluid, but this choice is sometimes very difficult and demands special considerations. 16 refs.