A Detailed Investigation of Gravity-Driven Separation Mechanisms for Horizontal Wells Under Dispersed Flow Conditions

Abstract Downhole separation represents a current challenge in producing horizontal wells where new separation mechanisms need to be identified. A new facility has been designed and built, representing a section of the downhole separator at the primary separation region of inverted shrouds. The study is focused on how the bubbles are captured into the separator for dispersed flow conditions. High-speed video cameras and proper lights are utilized to capture the bubbles’ motion. Computer vision techniques are used to create an object detection and tracking program capable of describing bubble trajectories. Computational Fluid Dynamics (CFD) simulations complement the experimental results. Poor boy, Ecometer, Patterson, and other configurations have been tested. Results show that radial velocity is the main contributor to forcing the bubbles into the tubing-shroud section. For the considered conditions, all the bubbles captured in the tubing-shroud section are dragged into the pump suction, suggesting that the 6 in./s design rule should be revised. Based on the observation, different geometries have been envisioned to increase separation efficiency. This study shows that liquid flow rate and deviation angle significantly impact separation efficiency. However, the geometries considered in the separation region have little impact on separation efficiency.