Unified Thermodynamics and Life of Field in Modelling Complex Upstream Facilities

Abstract

Among the hidden and critical challenges in the process modelling of upstream projects are the limitations of compositional capabilities in Integrated Production Modelling (IPM) simulations comprising of complex processing facilities and the inadequacy of steady state and transient state simulations to represent the facilities operability across design life. These challenges become more crucial as future developments are moving to deeper waters and dirtier hydrocarbons. By implementing Unified Thermodynamics with a single fluid model, MultiflashTM Cubic Plus Association (MF-CPA), all the fluid phases as well as the solid phases such as gas hydrates, waxes, asphaltenes and mercury partitioning can be modelled simultaneously within the IPM itself. The Life of Field (LOF) method enables the understanding of how the different parts of the system in the IPM interact when concepts are changed. The combination of both Unified Thermodynamics and LOF enables front end and operational studies to be performed accurately and efficiently. The case study shows the impact of two different processing facilities' arrival pressures on the production profile, project scheduling, material selection, gas hydrate formation risk and inhibition requirements, gas compression and turbine performance and sizing, mercury partitioning and CO2 production. By anticipating these changes more accurately, underpinned by MF-CPA, overly conservative equipment sizing can be avoided to reduce project CAPEX and improve asset efficiency across field life. This paper demonstrates the integrated application of process simulation and flow assurance tools from wellbore to customer to optimise project workflows and decision making for optimised investment.