The published work literature on pressure drop in a single phase flow is reviewed.While many papers have
been published on the prediction of bottom-hole pressure in single phase vertical gas wells; there are not many studies that
show the effects of friction on this flow of interest. A model has thus far been derived from first principle as an
improvement over Sukkar and Cornell's approach of calculating bottom-hole pressure by the introduction of friction
factor in the turbulent region. Suggested friction factor under varying conditions are explicitly discussed.Finally, two
models are compared, one considered the friction effect while the other assumed a non friction factor.