Design of a high-pressure research flow loop for the experimental investigation of liquid loading in gas wells

Abstract

Liquid loading in producing gas wells is the inability of the produced gas to remove produced liquids from the wellbore. A review of existing flow loops worldwide revealed that specialized areas of research such as liquid loading in gas wells are still lacking dedicated test facilities. This project presents the design of a new dedicated facility to be located at the TowerLab at the Richardson building with adequate operating conditions to reproduce the flow regimes encountered prior to and after the onset of liquid loading in gas wells. The facility consists of a compressed air system, pipelines for air and water, a pressure vessel containing glass beads, an injection manifold, and flow control and monitoring devices. Our results show that three compressors working in parallel is the most technical and economic configuration for the TowerLab based on the overall costs provided by the supplier, the footprint but most importantly the flexibility. The design of the pressure vessel required a cylindrical body with top and bottom welded-flat head covers with multiple openings to minimize its weight. The pipelines connecting major equipment and injection manifold located at the pressure vessel were selected based on the superficial velocities for air and water. These values also showed the need for independent injection using two manifolds instead of commingling flow through a tee joint. The use of digital pressure gauges with an accuracy of 0.05 to 25% and coriolis or vortex meters to measure air flowrate is also suggested. For the water line, installation of turbine meters results in the most economic approach.