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U.S. Department of Energy
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Production decline analysis

Conference · · Trans. - Geotherm. Resour. Counc.; (United States)
OSTI ID:6166836
 [1];
  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-
Journal Information:
Trans. - Geotherm. Resour. Counc.; (United States), Journal Name: Trans. - Geotherm. Resour. Counc.; (United States) Vol. 4; ISSN TGRCD
Country of Publication:
United States
Language:
English