A generalized friction-factor correlation to compute pressure drop in horizontal wells

This work investigates the effect of fluid ingress on flow through perforat ions in a horizontal wellbore and correlates this effect in the form of an apparent friction factor. The investigation uses theoretical and experiment al models. It is shown that when there is no influx. the perforations, or s lots, on the well surface cause a reduction in the pressure gradients propo rtional to their area. The wellbore pressure gradients increase with influx from perforations, but unless the ratio of the influx rate to the wellbore flow rate is sufficiently large, pressure gradients are lower than those o f an unperforated well. The results of this study are combined to develop a generalized friction-factor correlation that is a function of the Reynolds number and the ratios of the influx to wellbore flow rate and perforation to wellbore diameters.