Patent ID: 7526407
Filing Date: 2009-04-28
Classification: E21B,G01F

Abstract:
1. A method for detecting water breakthrough in a well production, the method comprising: measuring and monitoring temperature and pressure before and after a pressure drop element; implementing the measurements together with other relevant process parameters in a model for calculating expected pressure and temperature after a pressure drop element; comparing the result from the model to the actual pressure and temperature measurements; receiving with the model three of the four following parameters, inlet pressure, inlet temperature, outlet pressure, outlet temperature, said model comprising a three-phase flash model that includes heat of evaporation of water and partial pressure of water with or without dissolved components lowering the water vapor pressure such as salt and/or alcohol; calculating with said model the fourth parameter based on the three given parameters; measuring the actual fourth parameter; and comparing the actual fourth parameter to the computed fourth parameter, and determining that a water breakthrough has actually occurred if the deviation between the measured and the computed parameter is considerably larger than that which could be explained from the level of confidence of the model and the uncertainty of measurement.