Production decline analysis

Conference · Mon Sep 01 04:00:00 EDT 1980 · Trans. - Geotherm. Resour. Counc.; (United States)

OSTI ID:6166836

Zais, E J ^[1]; Bodvarsson, G

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1. Elliot Zais and Associates, Inc., Corvallis, OR

Data from Wairakei, The Geysers, Larderello and Cerro Prieto were analyzed using traditional production decline methods borrowed from the petroleum industry. Arp's exponential equation works quite well in many cases. His hyperbolic equation works very poorly. Several type curves were tried with little success. Coats and Bodvarsson each developed easy to use methods for predicting either pressure or production given the other and historical data. Coats's influence function model requires only production and pressure data from which an influence function step or impulse response can be calculated. No reservoir model need be assumed. Bodvarsson's linearized free surface assumes that a free liquid surface is present and that enough data are available to define a sinking velocity. The sinking velocity equals permeability times gravity divided by porosity times kinetic viscosity. Both methods worked well on the data tested.

• OSTI ID: 6166836
• Report Number(s): CONF-800920-
• Conference Information: Journal Name: Trans. - Geotherm. Resour. Counc.; (United States) Journal Volume: 4
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150904* -- Geothermal Engineering-- Geothermal Reservoir & Well Performance
CALCULATION METHODS
CERRO PRIETO GEOTHERMAL FIELD
GEOTHERMAL FIELDS
GEYSERS GEOTHERMAL FIELD
LARDERELLO GEOTHERMAL FIELD
MATHEMATICAL MODELS
MATHEMATICAL SPACE
PERMEABILITY
POROSITY
PRODUCTION
RESERVOIR PRESSURE
SPACE
VISCOSITY
WAIRAKEI GEOTHERMAL FIELD