ABSTRACT
Air drilling uses air or gas as the circulating medium. Because there are so many variables involved in air or gas drilling no one general method has been developed to predict the appropriate volumetric requirements for field use. In an attempt to alleviate this problem a computational model has been designed and developed which can analyze the pressure drop contributions for the complete air drilling system. This will facilitate the optimization of the air or gas pressure and volume requirements. The model is capable of analyzing the effects of variations in flow rate, sandpipe pressure, cutting size distribution, and loading.
Studies conducted using the computational model includes an analysis of several methods for determining pressure drop due to the solids phase. The results from these studies were compared with Industry Field Experience Data. Two of the methods indicated good agreement with the data.