Effect of annulus water on the wellbore heat loss from a steam injection well with insulated tubing
Recently completed field experiments using an instrumented string and test well have verified that the presence of annulus water in injection well annuli introduces a real and economically important heat loss mechanism - wellbore refluxing - for surface-generated steam. Measured boiling heat transfer rates at local hot spots are sufficient to maintain steady refluxing over a realistic range of injection conditions and overburden properties. It is shown that with the wellbore wet, the thermal properties of the cement and overburden, not those of the insulated tubulars, control the magnitude of the wellbore heat loss. Steady refluxing without venting at the wellhead has been observed; hence, oil field operators should not automatically assume that a nonventing annulus is dry. Insulated couplings have been demonstrated to reduce coupling heat loss by up to 35% in a dry well, and in wet wellbores to prevent significant boiling at the coupling, typically the primary source of refluxing. Heat loss estimates for refluxing or flooded wellbores indicate large incremental economic penalties, of the order of $100 million annually in the US alone. The successful demonstration of simple, easily implemented, insulated coupling designs, and the confirmation that wellbore heat loss in refluxing annuli scales with annulus pressure in a predictable manner, suggests that much of this loss is preventable. 15 references, 14 figures.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 5908147
- Report Number(s):
- CONF-850312-1; ON: DE85006741
- Resource Relation:
- Conference: SPE annual California regional meeting, Bakersfield, CA, USA, 25 Mar 1985
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COUPLINGS
THERMAL INSULATION
OIL WELLS
STEAM INJECTION
PIPES
FIELD TESTS
HEAT LOSSES
ENHANCED RECOVERY
EXPERIMENTAL DATA
PETROLEUM
DATA
ENERGY LOSSES
ENERGY SOURCES
FLUID INJECTION
FOSSIL FUELS
FUELS
INFORMATION
LOSSES
NUMERICAL DATA
RECOVERY
TESTING
WELLS
020300* - Petroleum- Drilling & Production