An experimental study of a shroud type downhole separator for a pumped horizontal or deviated well is presented in this study. The separator is located at high deviation angles (i.e., 45 to 80-degrees from the vertical). The effects of the upstream gas and liquid flow rates are evaluated in the performance of the downhole separator.
Traditionally, downhole separators are tested under steady-state conditions in vertical or close to vertical configurations. For those tests, the fluids were injected above or at the bottom of the separator in a vertical setting. The University of Tulsa's outdoor downhole separator facility was used in this study. The facility allows the injection of a two-phase mixture below the separator; the gas and liquid flow rates and the deviation angle can be varied. The global separation efficiency and the liquid holdup in the liquid-rich outlet were recorded and analyzed.
The experimental results demonstrated the effects of the gas and liquid flow rates and deviation angle on the behavior of downhole separators. It was found that as the deviation increases, the efficiency of the separator increases. It was also observed that efficiency decreases at deviations close to horizontal. The findings complement previous studies on shroud type downhole separators and demonstrate the operational capability of downhole separators under numerous conditions. Furthermore, the results provide conditions under which and where the separator can be operated efficiently in the field.