A Simulation coupling method for surface production system optimization is developed as part of an integrated operations (IO) project that aims to support the field rejuvenation program for a mature field. The objective is to unlock surface constraints and optimize field production via a production network-to-process facility coupling method. This method allows cross-discipline engineers to collaborate and perform comprehensive well deliverability assessment, evaluate network back-pressure and various facility constraints. Such collaboration also promotes the efficiency of optimization process.
The well-pipeline production network and surface facility simulation models are coupled within a single application in which the hydraulic and thermal streams are tied for modeling consistency. These are configured at the upstream end of the separator system where common boundaries are solved sequentially. A "loop-back" approach is applied to impose facility constraints to the network and the well performance will be assessed based on its response to the system back-pressure and constraints. The coupled model is optimized by a neural-network solver where constraints are set up based on operation requirement such as flaring limit, process limits, gas lift requirement, erosional velocity limit, etc.
Thorough analysis can be performed by incorporating and understanding the interactions between parameters and variables of the production system starting from the well, and progressing to the pipeline network, and to the processing facility. This allows personnel from multiple domains to collaborate and achieve the following:
Restrategizing the separator pressure system to meet the production target while embarking on the vision of operating with zero gas flaring. The sensitivities of production network potential against surface capacity can be performed to identify the potential optimized operating setpoints.
Reducing production deferment during prolonged operation equipment upset (i.e., when pump, compressor, or separator are shut down for maintenance). The deferment can be minimized by re-routing of production and/or re-allocating the gas lift distribution based on availability.
Anticipating potential operational interruptions if operating setpoints of the production network and/or facility system are changed. These changes can be due to operational requirement or production enhancement initiatives.
The coupling method provides critical insights to uncover opportunities of optimizing field production and minimizing production upset and interruption.
The integrated operation improves the optimization process by promoting the collaboration of multiple domains. The outcome of the coupling method should be used as basis for further transient analysis check prior to field implementation, which is an additional key facet to its technical viability in terms of operational safety and avoidance to potential risk of production interruption.