Model and Influencing Factors Analysis of Heat Transfer of Stream Injection Wellbore

In the process of the exploitation of heavy oil, the energy loss of well bore directly affects the effect of steam injection thermal recovery, reasonable thermal calculation model of stream injection well bore is important for establishing the surface energy of well bore. There are already many calculation models about well bore energy loss, however there are still shortcomings of the application on the actual on-site engineering calculations. In order to work with the reality of the scene better, in this paper based on the heat transfer characteristics of well bore, three engineering calculation models about heat loss, pressure drop, and dry-degree were established, and simulation software was accomplished, then the factors mainly impact the steam dryness inside the well bottom were analyzed. The results show that, 1) the calculated data keep high consistent with the actual well data, 2) the steam dryness of the well bottom declines more slowly with increasing the steam injection rate, and the steam dryness of the well bottom reduces with the increasing of the steam injection press, and the loss of the steam dryness decreases with the extension of injection time.