Optimising Long-Distance Gas Condensate Flowlines_Rev2

Optimising Long-Distance Gas Condensate Flowlines

This case study is drawn from a conceptual study carried out for an independent UK based Oil and Gas company. The flowline was sized by combining an integrated reservoir/flowline simulator with simple discounted cash flow economics. The operability of the flowline was also an important issue as the speed at which it could safely alter its production rate was stipulated in the Gas Sales Contract (GSC). The study demonstrates how many conceptual issues in gas condensate systems can be studied using steady state simulators, thus allowing transient simulation to be deferred until the later phases of design. Read More…

Optimising Tieback to Existing Facilities_Rev2

Optimising Tieback to Existing Facilities

This study was carried out for a US oil company operating in the central North Sea. It shows that even short conceptual studies can benefit tremendously from an integrated reservoir – flowline approach to analysis. Read More…

Optimisation of an Extension to an Existing North Sea Asset_Rev2

Optimisation of an Extension to an Existing North Sea Asset

This study was carried out for a UK based oil company operating in the North Sea wishing to extend one of its existing subsea production systems. The case study shows how as flowline systems grow they can become as much of a restriction to flow as the wells or reservoir. Therefore detailed evaluation of the overall deliverability is best achieved using an integrated reservoir model coupled to a representative well, flowline and riser network model. Such evaluations are now commonplace using the latest Life of Field simulation tools. Read More…

Life of Field Stability of a North Sea Oil Development_Rev2

Life of Field Stability of a North Sea Oil Development

Transient operability issues can significantly affect the NPV of a subsea developments. Severe slugging, for example, can dictate major design parameters such as flowline routes and diameters and hence affect the overall CAPEX. It can also affect revenue by reducing the operability of flowlineriser systems. Consequently such issues should be analysed at the earliest possible opportunity during design. By automating the analysis of the output from transient multiphase flow simulators it is possible to gain a greater understanding of the operability of such systems during conceptual design. This case study describes a method employed by FEESA on several previous Flow Assurance operability studies. Read More…

Life of Field Cooldown in Deepwater Developments_Rev2

Life of Field Cooldown in a Deepwater Development

Transient multiphase flowline simulators can help engineers understand many different Flow Assurance issues and have proved to be a useful tool during the design of many oil and gas developments. However, not all transient issues benefit from being studied using such complex and costly tools, either because the problem is straightforward or an accurate solution is not required or the simulator is not best suited to model the physical phenomenon of interest. Read More…

Life of Field Corrosion_Rev2

Life of Field Corrosion of a Flowline System

This corrosion study was carried out in conjunction with a large engineering company as part of a FEED for a deepwater development. A method was employed to aid communication between the Flow Assurance and Corrosion disciplines. This interdisciplinary approach removed the need to identify an arbitrary corrosion design case. Read More…

Hydrodynamic Slug Size in Multiphase Pipelines_Rev2

Hydrodynamic Slug Size in Multiphase Flowlines 

Hydrodynamic slugs are understood to be initiated by the instability of waves on the gas-liquid interface in stratified flow under certain flowing conditions. When hydrodynamic slugs are numerous, the pipeline is said to be operating in the slug flow regime. The slug flow regime is characterised by complex gas-liquid flows, often exhibiting chaotic behaviour. Read More…

Non-Newtonian

Non-Newtonian Gel Flow in a Pipeline

There are many analytical methods that can be employed by Flow Assurance engineers to great benefit and saving. One such example is for the analysis of Non-Newtonian fluids, such as gelled oils. A method has been developed and successfully employed on such diverse systems as a deepwater flowline containing a gelled oil and the effluent stream from a pharmaceutical reactor. Gelled oils in pipelines present a particularly difficult problem as their rheological behaviour can be a function of temperature and the history of how the gel was formed. Given these uncertainties, a fit for purpose simple model is described which predicts the flows of gels in pipes. This model provides a cost-effective and inexpensive alternative to expensive add-ons to transient simulators. Read More…

Wax Management in a Production System_Rev2

Wax Management in a Production System

This case history is based on a series of studies FEESA-IPM conducted on a deepwater daisy chained flowline tieback that blended a waxy oil with a cooler non waxy oil. Detailed modelling of the thermal hydraulics, wax phase equilibrium and wax deposition rates using a combination of Maximus, Multiflash and FloWax were key in the comparison of numerous wax solutions in order to develop a robust and economic Wax Management Strategy. Read More…

Phased Use of Maximus for Flow Specified Network Life of Field Optimisation

Maximus can be used as a very effective tool to carry out a rapid optimisation of a flow specified network utilising the Life of Field approach. The example presented is the expansion of an existing project to a system with a total of 51 wells, 8 platforms and 4 trunklines. The platforms feed gas into trunklines and the gas is transported to shore for processing and export. The challenge with optimising the network is that it is not intuitively apparent, given the number of platforms involved, when the design cases occur. The system had a number of constraints that had to be considered when optimising the design. Read More…