Three-dimensional, transient natural convection in inclined wellbores

Conference · Mon Jan 01 00:00:00 EST 1990

OSTI ID:5795027

McEligot, D M ^[1]; Denbow, D A ^[2]; Murphy, H D ^[3]

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1. Westinghouse Electric Corp., Middletown, RI (USA). Oceanic Div.
2. Software AG of North America, Inc., Lakewood, CO (USA)
3. Los Alamos National Lab., NM (USA)

The occurrence of natural conduction in a wellbore can affect geothermal gradient measurements and heat flow estimates. In the Hot Dry Rock geothermal concept, the wellbores are purposely inclined in the deep regions to enhance heat production. To simulate natural convection flow patterns in directionally drilled wellbores, experiments and analyses were conducted for a circular tube with length to diameter (L/D) ratio of 36 at angles of 0{degrees}, 20{degrees}, and 35{degrees} from the vertical. The tube was heated at the bottom and cooled at the top, and the insulation was adjusted so that approximately one- to two-thirds of the power dissipated was transferred through the tube wall to the surroundings. An aqueous solution of polyvinyl alcohol was employed as the working fluid in order to obtain low Rayleigh numbers corresponding to conditions in geothermal wellbores. Temperature distributions were measured for the three orientations and for several heating rates to demonstrate the effects of tube angle and Rayleigh number. Comparison with measurements showed good agreement of the predicted temperature levels for the maximum inclination and slightly poorer agreement for the other limit, a vertical tube. 50 refs., 9 figs.

• Research Organization: Los Alamos National Lab., NM (USA)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5795027
• Report Number(s): LA-UR-90-4427; CONF-910739-4; ON: DE91005936
• Resource Relation: Conference: ASME/AIChE/ANS national heat transfer conference, Minneapolis, MN (USA), 26-31 Jul 1991
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
GEOTHERMAL WELLS
NATURAL CONVECTION
FLOW MODELS
DIRECTIONAL DRILLING
EQUATIONS
FLUID MECHANICS
GEOTHERMAL GRADIENTS
HEAT FLOW
HEAT TRANSFER
HEATING RATE
HOT-DRY-ROCK SYSTEMS
INCLINATION
MASS TRANSFER
MEASURING METHODS
SIMULATION
STABILITY
T CODES
TEMPERATURE DISTRIBUTION
TEMPERATURE MEASUREMENT
THERMAL INSULATION
THREE-DIMENSIONAL CALCULATIONS
TRANSIENTS
WELL DRILLING
COMPUTER CODES
CONVECTION
DRILLING
ENERGY SYSTEMS
ENERGY TRANSFER
GEOTHERMAL SYSTEMS
MATHEMATICAL MODELS
MECHANICS
TEMPERATURE GRADIENTS
WELLS
Geothermal Legacy
150301* - Geothermal Exploration & Exploration Technology- Geophysical Techniques & Surveys