A simple correlation for estimating pressure drop in horizontal wells

Even though it has long been recognized that pressure drop along a horizontal wellbore cannot be neglected, little has been done to estimate the pressure drop with any rigor. The existing models are derived from pipeflow equations, therefore neglecting the presence of radial fluid movement perpendicular to the direction of bulk fluid flow. Recent experimental studies indicate that such a simplistic approach provides an optimistic behavior in a horizontal wellbore. This article presents a realistic representation of the pressure drop in a horizontal wellbore. Equations are derived from rigorous experiments conducted earlier and reported in the literature. They include the effect of radial fluid movement, perforation flow, gas-oil ratio, oil viscosity, bulk flow rate, water saturation and even the presence of asphaltenes in the crude oil. Even though the equations are based on experimental results, predictions apply to field situations. This aspect is verified with certain unpublished field data from USA and Canada.