Flow assurance for subsea gas production systems in the deep water of Mediterranean Sea with lower glycol injection rates.

2013 ◽  
Author(s):  
Wael Hamed A.Moati
2006 ◽  
Vol 46 (1) ◽  
pp. 395
Author(s):  
R. Freij-Ayoub ◽  
M. Rivero ◽  
E. Nakagawa

Offshore exploration and production is going to deep and ultra deep waters, driven by the depletion of continental shelf reserves and the high demand for hydrocarbons. This move requires the continued extension of existing technologies and the development of new technologies that will make the investment economically viable. Innovative flow assurance technology is needed to support ultra deepwater production, particularly within the concept of platform free fields where there is a need to minimise interventions.Hydrates present one of the major challenges in flow assurance. Deep and ultra deep water operations together with long tiebacks present the ideal conditions for the formation of hydrates which can result in pipeline blockage and serious operational and safety concerns. Methods to combat hydrates range between control and management. One main technique has been to produce the hydrocarbons outside of the thermodynamic stability domain of hydrates. This is achieved by keeping the temperature of the hydrocarbon above the stability temperature of hydrates by insulating the pipe line, or by introducing heat to the hydrocarbon. Another efficient way of combating hydrates has been to shift the hydrate phase boundary to lower temperatures by using chemicals like methanol and mono ethylene glycol (MEO) which are known as thermodynamic inhibitors. Within the last decade a new generation of hydrate inhibitors called low dosage hydrate inhibitors (LDHI) has been introduced. One type of these LDHI are kinetic hydrate inhibitors (KHI) that, when used in small concentrations, slow down hydrate growth by increasing the induction time for their formation and preventing the start of the rapid growth stage. Another approach to managing hydrates has been to allow them to form in a controlled manner and transport the hydrate-hydrocarbon slurry in the production pipe. In this paper we describe the various approaches used to combat hydrates to ensure flow assurance and we discuss the cons and pros of every approach and the technology gaps.


1998 ◽  
Vol 38 (1) ◽  
pp. 855
Author(s):  
K.P. Thiagarajan

Offshore oil and gas production is now reaching to great depths, in excess of 1000 m, in the Gulf of Mexico and the Campos Basin, offshore Brazil. It will not be long before Australian companies look towards probable reserves in deeper waters that still remain within the Australian exclusive economic zone. Production concepts for deep and ultra deep water thus need to be studied and researched, and a constant watch should be maintained on developments around the world in this area.This paper presents two popular, and constantly evolving, concepts for deep water, namely: tension leg platforms (TLP) and spars. Tension leg platforms have been in existence for about 14 years, and are actively sought for deep water by worldwide operating companies. They are vertically moored by means of taut tethers which present interesting motion characteristics and unique hydrodynamic problems. Spar platforms are currently being installed for production purposes. These are large deep draft cylindrical structures moored by catenary or taut spread mooring systems. Physical details, advantages and limitations of both systems are discussed.While many aspects of these production systems are now understood, there are still several unknowns. Deeper waters translate to newer problems. Potential problems of the future are discussed in this paper, and research needs are highlighted.


Author(s):  
Jian Su

Flow assurance is essential for economic and reliable production of oil and gas in deep water environment. The present paper discusses the complex physical phenomena involved in deep water production and the challenging engineering problems of flow assurance; and reviews recent works to understand the processes and tackle the problems. The following topics are discussed: flow regime transition, pressure drop, flow pattern, slug flow and severe slugging, transient multiphase flow, thermal insulation, insulation materials, active heating and wax deposition.


Author(s):  
Hilman Salleh

FPSOs have been a popular choice for deep water oil and gas production with many installations worldwide. Many of these floating production systems were tanker conversions and they are now approaching their mid-life or end of life hence, facing ageing issues relating to asset integrity. Concurrently, there are also requirements for these floating production systems to operate to operate beyond the design life. As most of this maintenance and refurbishment work is to be done while on station, there needs to be a structured process to ensure that all key areas of concerns are reviewed. This paper outlines the strategy available and addresses the issues and possible solutions to manage the life extension and ageing of FPSOs.


Author(s):  
Celso K. Morooka ◽  
Mauricio J. H. Suzuki ◽  
Paulo S. D. Pereira

The ever increase of global demand for petroleum and natural gas brings needs to discover new petroleum fields. Particularly in the Brazilian coast, these discoveries are located on more and more remote areas combined with harsh and aggressive petroleum fluid production, such as the case of recently announced pre-salt petroleum fields. Development of offshore systems for field production in this scenario demands sophisticated and innovative technological solutions. It brings the necessity for developments of frontier technologies to make viable design of oil and gas production systems to be applied for ultra deep water depth applications. Production riser is a very critical component of most offshore petroleum production systems. Riser acts as a physical connection between subsea wells and floating production facility at the sea surface. It conducts the oil and gas production, and sometimes, fluid or gas for injection into the petroleum reservoir. Wellhead control commands are also guided between the floating platform and the subsea system throughout the riser system. In the literature, many different riser systems have been proposed and extensively discussed for ultra deep water applications. Among others configurations, Steel Catenary Riser (SCR) appears as a technically feasible and economically viable solution. This system is comprised with a free hanging steel pipe, suspended from the platform directed to the wellhead in a catenary shape. In ultra deep water, the riser weight itself commonly is the limitation for application of this type of riser system. Once it requires a much more expensive floating production platform with larger capacity. Furthermore, it also can cause high concentrated stresses in some regions along the riser structure. Catenary shaped risers with lighter material such as Aluminum seem to be a very attractive alternative due to the great riser weight reduction observed. The present paper describes and proposes procedures for the design and operation of petroleum production riser system for ultra deep water application to produce high flow rate of oil and gas in a typical pre-salt petroleum field offshore Brazil condition. Results and discussions are shown through comparisons for catenary riser systems composed by steel pipe and other kind of lighter material. Case studies are conducted for water depth up to 3000 meters by parametric analysis. Current and waves effects along with floating platform motions and riser geometries are analyzed in order to identify critical conditions and to depict feasible solutions.


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