In the oil and gas industry, there can exist a significant cleavage between sub-surface and surface disciplines, with often very little mutual understanding of each other’s role and importance. A unilateral vision of the business is often observed in the ranks.
Who indeed has never seen a Geologist pester against “Surface Facilities people” who take so much time to deliver a platform after investment decision on a new prospect? Who has never seen a Project Manager complain about yet another production profile update weeks after the issuance of a surface facilities basis of design?
Two disciplines establish the interface between sub-surface and surface disciplines: the Reservoir Engineer and the Process Engineer.
A good Reservoir Engineer knows that each production profile must be discussed at an early stage with a Process Engineer in order to take account of any constraints on surface facilities. He / she will enquire on operating pressures of production plants, on the capacity of oil, water and gas handling facilities, on compression capacity and pressure, and on the use that the Process Engineer will make of his / her work. He / she will immediately inform the Process Engineer about any change that may occur, and which will impact his / her work.
A few dangers of this collaboration are insufficient communication and insufficient understanding of the use that either discipline will make of the obtained information. This can have expensive consequences. For example, a change in production profile, communicated at too late a stage in the design and fabrication of a production station, may require significant design modifications or worse, significant modifications to the equipment in fabrication.
Ideally, the integration of reservoir models with process models should be conducted, as much as reasonably practicable. However, this is not always as easy as it sounds. Indeed, reservoir simulation tools and process simulation tools are separate and different. They often operate on different bases, eg black oil versus compositional - although mainstream process simulation tools now offer black oil modelling options. Even when integrated modelling is feasible within a single package, it is at the loss of accuracy, flexibility, functionality or complexity for either of the disciplines. The practical solution is to build a ‘bridge’ between two specialist applications. This is a complex endeavour, which often takes a company policy and a significant amount of software programming, in collaboration with simulation package vendors.
In any case, a successful collaboration between the Reservoir Engineer and the Process Engineer results in the vanishing of the sub-surface / surface frontier and in a smooth and continuous assessment of each asset.