Multiphase flow simulator sub-modeling

1. A method comprising:

receiving information from at least one sensor of a fluid production network for a model of the fluid production network wherein the model comprises a plurality of sub-models;

synchronizing simulation of the plurality of sub-models with respect to time, wherein, during at least a portion of the simulation, a number of time steps for a first one of the sub-models differs from a number of time steps for a second one of the sub-models and an input value of one of the time steps of the first one of the sub-models is determined using at least one output value of at least one of the time steps of the second one of the sub-models;

via synchronizing simulation, outputting values for fluid flow variables of the model; and

based at least in part on one or more of the values for fluid flow variables of the model, outputting a control command to control at least one piece of equipment of the fluid production network.

2. The method of claim 1 wherein the simulation comprises common time points wherein a number of time steps for one of the sub-models differs from a number of time steps for another one of the sub-models at one of the common time points.

3. The method of claim 1 comprising a production model, a pipeline network model and a plurality of well models wherein the pipeline network model is a sub-model of the production model and wherein the plurality of well models are sub-models of the pipeline network model.

4. The method of claim 1 wherein the synchronizing comprises performing the simulation of the plurality of sub-models at least in part in parallel.

5. The method of claim 1 wherein the synchronizing simulation comprises adjusting at least one time step associated with one of the plurality of sub-models.

6. The method of claim 1 wherein at least two of the sub-models are mutually dependent.

7. The method of claim 1 wherein the synchronizing simulation comprises transferring information from one of the sub-models to another one of the sub-models.

8. The method of claim 1 wherein the synchronizing simulation utilizes minor time steps and major time steps.

9. The method of claim 1 wherein the synchronizing simulation comprises time stamping information generated by sub-model simulation.

10. The method of claim 1 wherein the synchronizing simulation comprises storing values for fluid flow variables for at least two times and interpolating the values with respect to time.

11. The method of claim 1 wherein the input value of one of the time steps of the first one of the sub-models is determined via interpolation using output values of a plurality of time steps of the second one of the sub-models.

12. A system comprising:

an interface;

a processor;

memory accessible by the processor; and

processor-executable instructions stored in the memory wherein the instructions comprise instructions to instruct the system to

receive, via the interface, information from at least one sensor of a fluid production network for a model of the fluid production network wherein the model comprises a plurality of sub-models;

synchronize simulation of the plurality of sub-models with respect to time wherein, during at least a portion of the simulation, a number of time steps for a first one of the sub-models differs from a number of time steps for a second one of the sub-models and an input value of one of the time steps of the first one of the sub-models is determined using at least one output value of at least one of the time steps of the second one of the sub-models;

via the simulation, output values for fluid flow variables of the model; and

based at least in part on one or more of the values for fluid flow variables of the model, output a control command to control at least one piece of equipment of the fluid production network.

13. The system of claim 12 wherein the processor-executable instructions comprise instructions to instruct the system to implement a scheduler.

14. The system of claim 12 wherein the input value of one of the time steps of the first one of the sub-models is determined via interpolation using output values of a plurality of time steps of the second one of the sub-models.

15. One or more non-transitory computer-readable storage media comprising computer-executable instructions executable by a computer, the instructions comprising instructions to:

receive information from at least one sensor of a fluid production network for a model of the fluid production network wherein the model comprises a plurality of sub-models;

synchronize simulation of the plurality of sub-models with respect to time wherein, during at least a portion of the simulation, a number of time steps for a first one of the sub-models differs from a number of time steps for a second one of the sub-models and an input value of one of the time steps of the first one of the sub-models is determined using at least one output value of at least one of the time steps of the second one of the sub-models;

via the simulation, output values for fluid flow variables of the model; and

based at least in part on one or more of the values for fluid flow variables of the model, output a control command to control at least one piece of equipment of the fluid production network.

16. The one or more non-transitory computer-readable storage media of claim 15 wherein the fluid production network comprises a substantially vertical conduit and a substantially horizontal conduit and wherein a time step for simulation of fluid flow in the substantially vertical conduit is less than a time step for simulation of fluid flow in the substantially horizontal conduit.

17. The one or more non-transitory computer-readable storage media of claim 15 wherein the fluid production network comprises a multiphase fluid production network.

18. The one or more non-transitory computer-readable storage media of claim 15 wherein the values comprise values for fluid flow variables at a plurality of different times.

19. The one or more non-transitory computer-readable storage media of claim 15 wherein the input value of one of the time steps of the first one of the sub-models is determined via interpolation using output values of a plurality of time steps of the second one of the sub-models.