Modeling of multiple thermal fluid circulation in horizontal section of wellbores

Abstract

The development of heavy oil reservoirs has broad prospects. Because heavy oil reservoirs have the characteristics of high viscosity and poor fluidity, they often need to be heated. For heavy oil reservoirs, the effect of simple steam injection development is limited. By mixing superheated steam or steam with non-condensable gas, the development effect of heavy oil can be improved. Due to the high viscosity of heavy oil reservoirs, the initial injection capacity of the heat carrier is poor, and cyclic preheating is often required. In this paper, through theoretical research, the process of multi-element thermal fluid injection in heavy oil reservoirs is studied. The circulation preheating characteristics of the multi-element thermal fluid inside the wellbore are analyzed. Results show that for different ratios of nitrogen to carbon dioxide: when the multi-element thermal fluid flows from the finger end (1000 m) to the heel end (0 m) of the annular space, the oil layer heat absorption rate first drops and then rises.