Systems and methods for simulating fluid properties in a production system include receiving data from a sensor. The data represents a first property of a fluid that is measured by the sensor. A second property of the fluid is estimated based at least in part on the measured first property. A third property of the fluid is calculated using the estimated second property. Calculating the third property includes running a first simulation on a first simulator and running a second simulation on a second simulator. The first and second simulations at least partially overlap in the time domain. It is then determined whether results of the first and second simulations converge to a common value.