Abstract
An experimental study investigating the effects of end of tubing (EOT) on the two-phase gas-liquid flow behavior in horizontal wells was performed. The experimental data were used to develop methodologies to determine the optimum EOT location for the observed flow types: stable and cyclic flows. Total pressure drop, liquid inventory and the two-phase flow hydrodynamic behavior were analyzed to determine the optimum EOT location criteria. Tubingless completion and four packerless EOT locations were tested using a transparent laboratory-scale flow loop facility resembling two horizontal well configurations: toe-up and toe-down with 1-in. tubing and 2-in. casing. Water and compressed air were used as test fluids with various constant flow rates under low pressure. Minimum total pressure drop in the well was used to determine the optimum EOT location for stable flow. Various total pressure drop vs. EOT location relationships were observed under different operating conditions. Under low gas flowrates, installing tubing may promote severe slugging (SS) for a toe-up system. EOT located at kick-off point may be preferred as it showed the least test number of points with SS behavior. In addition, this location generated the lowest liquid holdup in the tubing and backpressure to the lateral section in most cases. The observations to explain these findings and the comparison of the tested EOT locations in handling SS were discussed.
