Richard S. Carden Grace, Shursen, Moore, & Associates Inc. Amarillo, Tex.
Drilling horizontal wells with air as the circulating medium is not a common practice; however, air has some distinct advantages over drilling mud. They are:
Significant increase in rate of penetration which leads to shorter drilling time
Elimination of lost circulation problems, especially in areas of very low bottom hole pressures
Continual drill stem test of potential producing formations
Minimal damage to the formation.
Unfortunately, there are some disadvantages to drilling with air: