1. A method of determining rate and phase of fluid produced from or injected into a well, the method comprising: obtaining first temperature and pressure measurements from sensors at the well; applying, by a processor, the first temperature and pressure measurements to a plurality of predictive well models to calculate an estimated value of fluid rate and phase composition from each of the predictive well models responsive to the temperature and pressure measurements; deriving a first fluid rate and phase composition result from the estimate value of fluid rate and phase composition from each of the predictive well models; storing, in a memory, the first fluid rate and phase composition result and a time indicator associated with a time the first temperature and pressure measurements were obtained; obtaining second temperature and pressure measurements from the sensors at the well; comparing the second temperature and pressure measurements with the first temperature and pressure measurements; and responsive to the second temperature and pressure measurements matching the first temperature and pressure measurements within a tolerance limit, storing, in the memory, the first fluid rate and phase composition result associated with a second time indicator associated with a time the second temperate and pressure measurements were obtained.