Viscosity reduction technology by closed hot water circulation in hollow sucker rod

Key words:  heavy oil recovery  hollow sucker rod  closed hot water circulation  wellbore viscosity reduction

Abstract:

In order to enhance the produced fluid temperature and decrease the heat loss in crude oil well, the viscosity reduction technology by closed hot water circulation in hollow sucker rod was proposed, which makes full use of the heat carrying by circulating hot water and the insulation effect of annular space. As a result, produced fluid in the wellbore maintains a higher temperature, and the insulation effect was shown. The flow and heat exchange mathematical models of the fluid flowing along the wellbore were established on the basis of the viscosity reduction theory.The flow and heat exchange rules were solved, and the influences of mass production, insulation performance of insulation tube, oil viscosity, circular hot water flow and other factors on viscosity reduction effects were analyzed. The results show that the circulation process can effectively maintain the produced fluid temperature, which is propitious to reduce viscosity in wellbore effectively.It is characterized by low cost, less circular hot water, saving energy and reducing consumption.