A mechanistic model for computing fluid temperature profiles in gas-lift wells
- Univ. of North Dakota, Grand Forks, ND (United States)
- Chevron Overseas Petroleum Technology Co. (Kuwait)
In a continuous-flow gas-lift operation, gas is injected down the annulus into the tubing near the top of perforations. The intrinsic idea is to aerate the liquid column, thus providing the necessary stimulus for fluid flow. Because the volumetric gas rate is dependent upon both the pressure and temperature at the depth of injection, accurate knowledge of these entities cannot be overemphasized for an efficient lift. In particular, the behavior of the nitrogen gas charged in the dome is critically dependent upon the temperature prediction for the optimal performance of the bellows-charged gas-lift valves. Current practice entails use of a linear temperature profile for the annular fluid while applying empirical correlations for the tubing fluids. Improved temperature predictions are now possible for fluids in both conduits by modeling the heat and fluid flow problem at hand from first principles. In this work, they present a mechanistic model for the flowing temperature of the annular gas and the gas/liquid two-phase mixture in the tubing as a function of both well depth and production time, regardless of the well deviation angle. The model is based on energy balance between the formation and fluids flowing through each conduit. While flowing down the annulus, the cold gas injected at the wellhead continues to gain heat. The heat-transfer rate for the annular gas depends on the relative temperatures of the formation and the tubing fluid. They assume unsteady-state heat transfer in the formation and steady-state heat transfer in the tubular for a continuous-flow gas-lift operation.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 276204
- Journal Information:
- SPE Production and Facilities, Journal Name: SPE Production and Facilities Journal Issue: 3 Vol. 11; ISSN 1064-668X; ISSN SPRFEZ
- Country of Publication:
- United States
- Language:
- English
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