An analytic model for computing the countercurrent flow of heat in tubing and annulus system and its application: Jet pump

• Published in: Journal of petroleum science & engineering 2021-08, Vol.203, p.108492, Article 108492
• Main Authors: Hasan, A. Rashid, Jang, Minsoo
• Format: Article
• Language: English
• Subjects: Artificial lift; Counter-current flow; Heat balance-based ODE; Jet pumps; Tubing-annulus heat-transfer
• ISSN: 0920-4105; 1873-4715
• DOI: 10.1016/j.petrol.2021.108492

Shale fields are currently over-reliant on electric submersible pumps (ESPs) in the early stage of artificial lift despite its weakness to sandy flow and often failing within the first three months. Jet pumps are reliable and cost-effective alternatives to the ESPs. Current studies on jet pumps have focused on designing parameters for maximizing performance; however, there have been very few investigations on predicting temperature profiles in the wellbore with a jet pump in use. Fluid temperature influences viscosity; hence, the production of heavy oil. Typically, the heavier the hydrocarbon, the greater is the variation in viscosity with temperature. Therefore accurate temperature prediction is essential for the efficient design of heavy oil production facilities. This paper offers an analytic model to compute temperature profiles in the tubing and annulus. Results show a good match with a field data set. Data set from a well in Tah field in China is used to validate the model. In addition, sensitivity analyses were performed that showed that injection temperature affects the annulus temperature profile, leading to significant changes in frictional pressure loss at shallow depths. In contrast, injection rate has less influence on temperature profiles, although, of course, higher fluid velocity causes greater frictional losses. Results show that a hotter and relatively small flow rate leads to lesser pumping cost by reducing frictional pressure drop during the operation. The proposed model ideally requires the bottom-hole temperature as a boundary condition (BC). When subsurface temperature data are unavailable, as often the case due to cost, a computing method is offered in the paper for reliable temperature profile estimation from only two data points at the wellhead. •This work provides models for predicting fluid temperature inside the tube and the annulus, in a simple algebraic form.•The temperature difference between the two conduits is not large because heat capacity of injection fluid is relatively larger than thatof reservoir fluid.•Both injection rate and temperature are important in determining frictional pressure gradient for safe and effective production design..•Using proposed numerical iteration method, temperature distribution along the wellbore can be calculated only with the temperature data of at the surface..