Computer Programs

NAME OR DESIGNATION OF PROGRAM, COMPUTER, DESCRIPTION OF PROBLEM OR FUNCTION, METHOD OF SOLUTION, RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM, TYPICAL RUNNING TIME, UNUSUAL FEATURES OF THE PROGRAM, RELATED AND AUXILIARY PROGRAMS, STATUS, REFERENCES, MACHINE REQUIREMENTS, LANGUAGE, OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED, OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHOR, MATERIAL, CATEGORIES

[ top ]

[ top ]

To submit a request, click below on the link of the version you wish to order. Rules for end-users are
available here.

Program name | Package id | Status | Status date |
---|---|---|---|

SHAFT-79 | NESC0893/01 | Tested | 20-NOV-1981 |

Machines used:

Package ID | Orig. computer | Test computer |
---|---|---|

NESC0893/01 | CDC 7600 | CDC 7600 |

[ top ]

3. DESCRIPTION OF PROBLEM OR FUNCTION

SHAFT79 (Simultaneous Heat And Fluid Transport) is an integrated finite difference program for computing two-phase non-isothermal flow in porous media. Although designed for simulating production and injection in geothermal reservoirs, it is, or can be readily modified to be, applicable to other two-phase problems. SHAFT79 solves coupled mass and energy balance equations based on the following major assumptions: the physical system is a system of porous rock saturated with a one- component fluid in liquid and vapor form; all rock properties, except porosity, i.e., density, specific heat, thermal conductivity, and absolute permeability are independent of temperature, pressure, or vapor saturation: and liquid, vapor, and rock matrix are at the same temperature and pressure at all times. Capillary pressure is neglected.

SHAFT79 (Simultaneous Heat And Fluid Transport) is an integrated finite difference program for computing two-phase non-isothermal flow in porous media. Although designed for simulating production and injection in geothermal reservoirs, it is, or can be readily modified to be, applicable to other two-phase problems. SHAFT79 solves coupled mass and energy balance equations based on the following major assumptions: the physical system is a system of porous rock saturated with a one- component fluid in liquid and vapor form; all rock properties, except porosity, i.e., density, specific heat, thermal conductivity, and absolute permeability are independent of temperature, pressure, or vapor saturation: and liquid, vapor, and rock matrix are at the same temperature and pressure at all times. Capillary pressure is neglected.

[ top ]

4. METHOD OF SOLUTION

The solution method is an explicit-implicit integrated finite difference approach which allows a flexible geometric description because it does not distinguish between one-, two-, or three-dimensional regular or irregular geometries. The non- linear finite difference equations are solved using the Newton- Raphson method. In SHAFT79 a fluid table is used to provide the equilibrium thermodynamic properties of the fluid filling the void space - temperature, pressure, vapor saturation, heat conductivity, liquid and vapor viscosities, densities, specific interval energies - as functions of fluid density and fluid specific internal energy. All thermodynamic information including derivatives is obtained from the fluid table by bivariate interpolation.

The solution method is an explicit-implicit integrated finite difference approach which allows a flexible geometric description because it does not distinguish between one-, two-, or three-dimensional regular or irregular geometries. The non- linear finite difference equations are solved using the Newton- Raphson method. In SHAFT79 a fluid table is used to provide the equilibrium thermodynamic properties of the fluid filling the void space - temperature, pressure, vapor saturation, heat conductivity, liquid and vapor viscosities, densities, specific interval energies - as functions of fluid density and fluid specific internal energy. All thermodynamic information including derivatives is obtained from the fluid table by bivariate interpolation.

[ top ]

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

SHAFT79 has been developed only for systems of water and rock. The fluid table covers most of the equation of state of water substance in the temperature range of 5 to 400 degrees C and the pressure range of 0.5 to 220 bar, which is adequate for most geothermal applications.

SHAFT79 has been developed only for systems of water and rock. The fluid table covers most of the equation of state of water substance in the temperature range of 5 to 400 degrees C and the pressure range of 0.5 to 220 bar, which is adequate for most geothermal applications.

[ top ]

[ top ]

[ top ]

8. RELATED AND AUXILIARY PROGRAMS

The fluid table is generated by executing two auxiliary programs included in the package, WATER and PROPER. WATER computes and tabulates the steam table equations as given by the International Formulation Committee (IFC,1967). PROPER numerically inverts these tables into functions of viscosities and densities and appends parameters other than temperature, pressure and vapor saturation. The tabulation is done in such a way that interpolation does not occur across the saturation line, where derivatives change in discontinuous fashion.

SHAFT79 is one of a set of five geothermal codes. The others are: ANALYZE for multiwell, multirate well test parameter determination (NESC Abstract 891); CCC for one-phase conduction, convection; and compaction (NESC Abstract 892); TERZAGI for isothermal fluid flow and subsidence (NESC Abstract 894); and WELBORE for steady and transient geothermal wellbore flow (NESC Abstract 895).

The fluid table is generated by executing two auxiliary programs included in the package, WATER and PROPER. WATER computes and tabulates the steam table equations as given by the International Formulation Committee (IFC,1967). PROPER numerically inverts these tables into functions of viscosities and densities and appends parameters other than temperature, pressure and vapor saturation. The tabulation is done in such a way that interpolation does not occur across the saturation line, where derivatives change in discontinuous fashion.

SHAFT79 is one of a set of five geothermal codes. The others are: ANALYZE for multiwell, multirate well test parameter determination (NESC Abstract 891); CCC for one-phase conduction, convection; and compaction (NESC Abstract 892); TERZAGI for isothermal fluid flow and subsidence (NESC Abstract 894); and WELBORE for steady and transient geothermal wellbore flow (NESC Abstract 895).

[ top ]

10. REFERENCES

- K. Pruess, J.M. Zerzan, R.C. Schroeder, and P.A. Witherspoon,

Description of the Three-dimensional Two-phase Simulator SHAFT78

for Use in Geothermal Reservoir Studies, Paper SPE-7699, presented at the Fifth Symposium on Reservoir Simulation, Denver, Colorado,

1979.

- K. Pruess, G. Bodvarsson, R.C. Schroeder, P.A. Witherspoon, R.

Marconcini, G. Neri, and C. Ruffilli,

Simulation of the Depletion of Two-phase Geothermal Reservoirs,

Paper SPE-8266, presented at the 54th Annual Technical Conference, Society of Petroleum Engineers, Las Vegas, Nevada, 1979, also

printed as,

LBL-9606, August 1979.

- K. Pruess, R.C. Schroeder,

Geothermal Reservoir Simulation with SHAFT79,

5th Geothermal Reservoir Engineering Workshop, Stanford,

California, 1979,

LBL-10066.

- K. Pruess, J.M. Zerzan, R.C. Schroeder, and P.A. Witherspoon,

Description of the Three-dimensional Two-phase Simulator SHAFT78

for Use in Geothermal Reservoir Studies, Paper SPE-7699, presented at the Fifth Symposium on Reservoir Simulation, Denver, Colorado,

1979.

- K. Pruess, G. Bodvarsson, R.C. Schroeder, P.A. Witherspoon, R.

Marconcini, G. Neri, and C. Ruffilli,

Simulation of the Depletion of Two-phase Geothermal Reservoirs,

Paper SPE-8266, presented at the 54th Annual Technical Conference, Society of Petroleum Engineers, Las Vegas, Nevada, 1979, also

printed as,

LBL-9606, August 1979.

- K. Pruess, R.C. Schroeder,

Geothermal Reservoir Simulation with SHAFT79,

5th Geothermal Reservoir Engineering Workshop, Stanford,

California, 1979,

LBL-10066.

NESC0893/01, included references:

- K. Pruess et al.:SHAFT-78, A Two-phase Multidimensional Computer Program for

Geothermal Reservoir Simulation. LBL-8264 (November 1979).

- K. Pruess and R. C. Schroeder:

SHAFT-79, USER'S MANUAL. LBL-10861 (March 1980).

- NESC Note 81-35 (May 9, 1981).

[ top ]

[ top ]

[ top ]

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

The

SHAFT79 program uses subroutine MA28A and associated routines from the U.K.A.E.A. Harwell Subroutine Library to solve a general sparse n x n system of linear equations. These routines, included as part of the package with Harwell's permission, are not in the public domain and extraction for other use is not permitted.

The

SHAFT79 program uses subroutine MA28A and associated routines from the U.K.A.E.A. Harwell Subroutine Library to solve a general sparse n x n system of linear equations. These routines, included as part of the package with Harwell's permission, are not in the public domain and extraction for other use is not permitted.

[ top ]

[ top ]

NESC0893/01

File name | File description | Records |
---|---|---|

NESC0893_01.001 | SHAFT-79 FORTRAN SOURCE | 5599 |

NESC0893_01.002 | FLUTAB3 LIBRARY DATA | 18297 |

NESC0893_01.003 | BRIGHAM & MORROW HALF-WATER HALF-STEAM | 24 |

NESC0893_01.004 | NATURAL HYDROTHERMAL CONVECTION SYSTEM | 109 |

NESC0893_01.005 | GARG'S RADIAL FLOW | 118 |

NESC0893_01.006 | WATER FORTRAN SOURCE | 273 |

NESC0893_01.007 | WATER SAMPLE INPUT | 5 |

NESC0893_01.008 | PROPER FORTRAN SOURCE | 1734 |

NESC0893_01.009 | PROPER SAMPLE INPUT | 364 |

NESC0893_01.010 | ISOT1 FILE | 4937 |

NESC0893_01.011 | OGRE FORTRAN SOURCE | 1014 |

NESC0893_01.012 | TEST CASE OUTPUT1 | 380 |

NESC0893_01.013 | TEST CASE OUTPUT2 | 883 |

NESC0893_01.014 | TEST CASE OUTPUT3 | 1223 |

Keywords: finite difference method, geothermal systems, reservoir engineering, simulation, thermodynamic properties, two-phase flow.