TY - JOUR
TI - Transient pressure and productivity analysis in carbonate geothermal reservoirs with changing external boundary flux
AU - Wang Dongying
AU - Yao Jun
AU - Cai Mingyu
AU - Liu Piyang
JN - Thermal Science
PY - 2017
VL - 21
IS - 11
SP - 177
EP - 184
PT - Article
AB - In this paper, a triple-medium flow model for carbonate geothermal reservoirs  with an exponential external boundary flux is established. The pressure  solution under constant production conditions in Laplace space is solved. The  geothermal wellbore pressure change considering wellbore storage and skin  factor is obtained by Stehfest numerical inversion. The well test  interpretation charts and Fetkovich production decline chart for carbonate  geothermal reservoirs are proposed for the first time. The proposed Fetkovich  production decline curves are applied to analyze the production decline  behavior. The results indicate that in carbonate geothermal reservoirs with  exponential external boundary flux, the pressure derivative curve contains a  triple dip, which represents the interporosity flow between the vugs or  matrix and fracture system and the invading flow of the external boundary  flux. The interporosity flow of carbonate geothermal reservoirs and changing  external boundary flux can both slow down the extent of production decline  and the same variation tendency is observed in the Fetkovich production  decline curve.