Abstract
Investigations on two-phase gas/liquid flow in pipes have been under study for nearly six decades. These studies have significantly assisted in managing fluid flow in the wellbore and surface networks, leading to the separation of phases and transmission of oil and gas into the market. This study summarizes some of the main lessons learned in flow through wellbores. Besides understanding some of the fundamental principles, we focused on the practical items of interest: Conventional production scenarios for oil and gas wells; Liquid loading in gas wells; Production in geothermal wells; Heat flow from fluid flow; Transient non-isothermal wellbore modeling; Well blowout in drilling operation; Estimating static geothermal and flowing-temperature gradients in gas wells; Heat mining with fluid circulation in wellbores. Given the diversity of the methods mentioned above, understanding flows in the wellbore and the reservoir becomes equally important. One critical item is the fluid temperature measurement associated with the fluid flow that enables validation of the fluid flow rate, besides revealing information about the reservoir characteristics.