NESC9834 GEOTHER.

1. NAME OR DESIGNATION OF PROGRAM:  GEOTHER.

3. DESCRIPTION OF PROGRAM OR FUNCTION

GEOTHER is a three-dimensional, geothermal reservoir simulation code. The model describes heat transport and flow of a single component, two-phase fluid in porous  media.

4. METHOD OF SOLUTION

It is based on the continuity equations for steam and water, which are reduced to two nonlinear partial differential equations in which the dependent variables are fluid pressure and enthalpy. These equations, describing three-dimensional effects, are approximated using finite-difference methods and are solved using an iterative technique. The nonlinear coefficients are  calculated using Newton- Raphson iteration, and an option is provided for using either upstream or midpoint weighting on the mobility terms.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM:

6. TYPICAL RUNNING TIME:

NEA-DB ran the test cases included in this package on a CDC CYBER 830 computer. Execution times varied from 70 to 203 CPU seconds depending on the problem.

7. UNUSUAL FEATURES OF THE PROGRAM

GEOTHER can be used to simulate the fluid-thermal interaction in rock that can be approximated by a porous media representation. It can simulate heat transport and the flow of compressed water, two-phase mixtures, and superheated steam in porous media over a temperature range of 10 to 300 degrees C. In addition, it can treat the conversion from single- to two-phase flow, and vice versa. It can be used for evaluation of a near repository spatial scale and a time scale of a
few years to thousands of years. The model can be used to investigate temperature and fluid pressure changes in response to thermal loading by waste materials.

8. RELATED AND AUXILIARY PROGRAMS:

10. REFERENCES

- INTERA Environmental Consultants, Inc.,
  GEOTHER: A Two-Phase Fluid Flow and Heat Transport Code,
  ONWI-434, April 1983.

- INTERA Environmental Consultants, Inc.:
  GEOTHER: A Two-Phase Fluid Flow and Heat Transport Code.
  ONWI-434  (April 1983)

11. MACHINE REQUIREMENTS:  56K words.

The test cases included in this package were run at NEA-DB on a CDC CYBER 830 computer with a fixed memory allocation of 252,000 (octal) words.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:

NOS2.5.1 (CDC CYBER 830).

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHORS

         C.R. Faust and J.W. Mercer
         U.S. Geological Survey
         Geo Trans, Inc.
         Office of Nuclear Waste Isolation
         Battelle Project Management Division
         505 King Avenue
         Columbus, Ohio 43201

File name	File description	Records
NESC9834_01.001	Information file	56
NESC9834_01.002	JCL and control information	31
NESC9834_01.003	GEOTHER FORTRAN source	2746
NESC9834_01.004	Sample problem 3A input	58
NESC9834_01.005	Sample problem 3B input	59
NESC9834_01.006	Sample problem 5A input	66
NESC9834_01.007	Sample problem 5B input	71
NESC9834_01.008	ONWI sample problem input	58
NESC9834_01.009	Sample problem output	11309