The Riser System Challenge for 1,800 Meters: Roncador Field, Offshore, Brazil

Author(s):  
Renato Marques Correˆa da Silva ◽  
Marcio Martins Mourelle ◽  
Jose´ Maurico Teixeira da Gama Lima ◽  
Francisco Henrique Ferreira Rodrigues

The paper presents a general overview of the technological challenge posed by the development of the phase 2, module 1A of Roncador field, offshore, Brazil. The field, discovered in 1996, encompasses reserves of 2.1 billion barrels of oil equivalent and is being developed in phases. This second phase, module 1A will be developed using solutions that will be among the world’s larger semi-submersible floating production unit displacement of more than 80,000 tons named Petrobras 52 (P-52). The platform will be moored in 1,800 meters (5905 ft) water depth. Peak production rates are targeted at 180,000 barrels per day (28,618m3/day) of oil and 130 million cubic feet per day (3.7 million m3/day) of natural gas. In addition to oil and associated gas processing capability to export and gas-lift, the unit will provide facilities capable of injecting up to 302,000 barrels per day (48,000 m3/day) of water. The subsea system was devised with all wells wet completed and directly connected to the production unit through around 44 SCRs (steel catenary risers) as base case. Moreover, alternative riser solutions such as flexible and hybrid risers are being screened and should be considered in the construction and installation bid. The gas lift system was defined through three subsea manifolds in order to narrow down the number of risers. The oil and gas export system was envisaged to be done through large diameter pipeline up to a shallow water fixed jacket hub facility which is linked with shore refinery pipeline network. The platform is scheduled for initial production in 2006. The feasibility study for the second phase, module 1A was performed in the third quarter of 2001. The main challenge was to produce an appraisal that mitigates the technology risk and also provides enough robustness to guarantee an attractive return rate. The unique field proven technology available to be considered in the feasibility study for the riser system as base case was the steel catenary riser system. On the other hand, other technologies were also investigated such as the riser tower system — similar to Girassol, West Africa; flexible riser system — to be qualified and the sub surface buoy, an in house solution. This paper describes the technical approach used into the feasibility in-house study that established the design base for the base case as well as the alternatives.

Author(s):  
Claudio Marcio Silva Dantas ◽  
Marcos Queija de Siqueira ◽  
Gilberto Bruno Ellwanger ◽  
Ana Lu´cia F. Lima Torres ◽  
Marcio Martins Mourelle

The steel catenary riser was adopted by Petrobras as a cost-effective alternative for oil and gas export and for water injection lines on deepwater fields, where large diameter flexible risers present technical and economic limitations. The installation of the P-18 SCR was a pioneer project of a free-hanging steel catenary riser linked to a semi-submersible [1] and demonstrated the technical feasibility of the concept. Fatigue damage verification is an important issue in SCR design, demanding a high number of loading cases to be analyzed. The random time domain nonlinear analysis is considered an attractive and reliable tool for fatigue analysis as nonlinearities are properly modeled and the random behaviour of environmental loadings is considered. As time domain analysis is high computer time consuming, the frequency domain analysis has been considered as an alternative tool for the initial phases of riser design to be used mainly for fatigue damage verification. This paper presents a methodology developed to perform a linearized frequency domain analysis aiming at fatigue damage verification. Two drilling risers were analyzed with the frequency domain procedure developed. The model of a steel lazy-wave riser was analyzed both in frequency and time domain in order to compare fatigue damage results. The analyses were performed using the Petrobras’s in-house computer codes ANFLEX, ALFREQ and POSFAL developed and implemented as part of projects from CENPES/PETROBRAS with “COPPE/UFRJ -The Engineering Post-Graduating Coordination of the Federal University of Rio de Janeiro”.


Author(s):  
Ana Lu´cia F. Lima Torres ◽  
Enrique Casaprima Gonzalez ◽  
Marcos Queija de Siqueira ◽  
Claudio Marcio Silva Dantas ◽  
Marcio Martins Mourelle ◽  
...  

The free-hanging SCR (Steel Catenary Riser) was adopted by Petrobras as a cost-effective alternative for oil and gas export lines on deepwater fields, where large diameter flexible risers present technical and economic limitations. It is considered an available technology for semi-submersible application. There was interest in applying SCR’s attached to FPSO (Floating, Production, Storage and Offloading) units due to the trend of using these units for exploration and production in Brazilian deep waters. This alternative has to be carefully studied due to the high offsets and heave motions imposed by the vessel on the top of the riser. This work presents the approach and methodology adopted in Petrobras to study the structural integrity and feasibility of a lazy-wave SCR attached to a bow turret-moored FPSO at a water depth of 1290 m. The analysis was performed using the Petrobras’s in-house computer codes ANFLEX and POSFAL developed and implemented as part of projects from CENPES with “COPPE/UFRJ - The Engineering Post-Graduating Coordination of the Federal University of Rio de Janeiro”. For VIV (Vortex Induced Vibration) fatigue damage calculation SHEAR7 was used.


2019 ◽  
Vol 14 (2) ◽  
pp. 142-147
Author(s):  
S.R. Kildibaeva ◽  
E.T. Dalinskij ◽  
G.R. Kildibaeva

The paper deals with the case of damage to the underwater pipeline through which oil and associated gas are transported. The process of oil and gas migration is described by the flow of a multiphase submerged jet. At the initial moment, the temperature of the incoming hydrocarbons, their initial velocity, the temperature of the surrounding water, the depth of the pipeline is known. The paper considers two cases of different initial parameters of hydrocarbon outflow from the pipeline. In the first case, the thermobaric environmental conditions correspond to the conditions of hydrate formation and stable existence. Such a case corresponds to the conditions of the hydrocarbons flow in the Gulf of Mexico. In the second case, hydrate is not formed. Such flows correspond to the cases of oil transportation through pipelines in the Baltic sea (for example, Nord stream–2). The process of hydrate formation will be characterized by the following dynamics of the bubble: first, it will be completely gas, then a hydrate shell (composite bubble) will begin to form on its surface, then the bubble will become completely hydrate, which will be the final stage. The integral Lagrangian control volume method will be considered for modeling the dynamics of hydrocarbon jet propagation. According to this method, the jet is considered as a sequence of elementary volumes. When modeling the jet flow, the laws of conservation of mass, momentum and energy for the components included in the control volume are taken into account. The equations are used taking into account the possible formation of hydrate. Thermophysical characteristics of hydrocarbons coming from the damaged pipeline for cases of deep-water and shallow-water pipeline laying are obtained. The trajectories of hydrocarbon migration, the dependence of the jet temperature and density on the vertical coordinate are analyzed.


2021 ◽  
Author(s):  
Ning He ◽  
Hu Yang ◽  
Fanli Xu ◽  
Yongming Cheng

Abstract A riser is a key component for transporting produced oil and gas from the subsea wells to the surface production vessel. Through nearly 30 years of design and implementation, Steel Catenary Risers (SCRs) have been found to have the advantages of relatively low cost and good adaptability to floating platform’s motion. This paper investigates deepwater SCR system design for the Lingshui 17-2 (termed LS17-2) project. This paper first introduces a SCR system for the LS17-2 project. The field for this project is located in the northern South China Sea, with water depth of 1220m to 1560m. LS17-2 consists of a subsea production system, a deep-draft semi-submersible (SEMI), and an export riser/pipeline. The platform was designed to have a large storage capacity with a variable draft during its operation. Based on deepwater SCR engineering experience, the key SCR design challenges are summarized from the engineering executive perspective. The challenges to the SCR system design for the LS17-2 project include harsh environment condition in South China Sea and the impact on fatigue design for the requirement of 30-years’ service life. They call for design optimization and innovative ideas. The engineering design and analysis are discussed together solutions. To demonstrate the deepwater SCR system design for LS17-2 project, examples are provided to illustrate the challenges and solutions. The experience learned from this paper should have significant relevance to future SCR design.


Author(s):  
Mark McDougall ◽  
Ken Williamson

Oil and gas production in Canada’s west has led to the need for a significant increase in pipeline capacity to reach export markets. Current proposals from major oil and gas transportation companies include numerous large diameter pipelines across the Rocky Mountains to port locations on the coast of British Columbia (BC), Canada. The large scale of these projects and the rugged terrain they cross lead to numerous challenges not typically faced with conventional cross-country pipelines across the plains. The logistics and access challenges faced by these mountain pipeline projects require significant pre-planning and assessment, to determine the timing, cost, regulatory and environmental impacts. The logistics of pipeline construction projects mainly encompasses the transportation of pipe and pipeline materials, construction equipment and supplies, and personnel from point of manufacture or point of supply to the right-of-way (ROW) or construction area. These logistics movement revolve around the available types of access routes and seasonal constraints. Pipeline contractors and logistics companies have vast experience in moving this type of large equipment, however regulatory constraints and environmental restrictions in some locations will lead to significant pre-planning, permitting and additional time and cost for material movement. In addition, seasonal constraints limit available transportation windows. The types of access vary greatly in mountain pipeline projects. In BC, the majority of off-highway roads and bridges were originally constructed for the forestry industry, which transports logs downhill whereas the pipeline industry transports large equipment and pipeline materials in both directions and specifically hauls pipe uphill. The capacity, current state and location of these off-highway roads must be assessed very early in the process to determine viability and/or potential options for construction access. Regulatory requirements, environmental restrictions, season of use restrictions and road design must all be considered when examining the use of or upgrade of existing access roads and bridges. These same restrictions are even more critical to the construction of new access roads and bridges. The logistics and access challenges facing the construction of large diameter mountain pipelines in Western Canada can be managed with proper and timely planning. The cost of the logistics and access required for construction of these proposed pipeline projects will typically be greater than for traditional pipelines, but the key constraint is the considerable time requirement to construct the required new access and pre-position the appropriate material to meet the construction schedule. The entire project team, including design engineers, construction and logistics planners, and material suppliers must be involved in the planning stages to ensure a cohesive strategy and schedule. This paper will present the typical challenges faced in access and logistics for large diameter mountain pipelines, and a process for developing a comprehensive plan for their execution.


Author(s):  
Tom Zimmerman ◽  
Chris Timms ◽  
Jueren Xie ◽  
James Asante

This paper contains the results of an experimental and analytical research program to determine the compressive buckling resistance of large-diameter, spiral-welded linepipe. Buckling resistance is important for pipe intended for service in Arctic, oil and gas pipeline systems, where pipes may be subjected to high bending strains caused by various ground movement events. The experimental work consisted of four full-scale tests of 30-inch (762 mm) diameter pipe subjected to various combinations of internal pressure, axial force and bending. The pipe specimens were fabricated using two material grades (X70 and X80) and two D/t ratios (82 and 48). Finite element analyses of the four tests were conducted to develop a better understanding of specimen behavior. The results suggest that spiral welded linepipe is as good as longitudinally welded line pipe in terms of buckling capacity. The spiral weld seam was in no way detrimental to the pipe performance.


2016 ◽  
pp. 93-97
Author(s):  
D. G. Lapin ◽  
D. A. Fomin ◽  
B. B. Kvesko

The article considers the most effective and environmentally friendly methods of utilization of associated petroleum gas (APG) for advanced oil and gas companies, as well as the developed method of utilization of associated gas using downhole steam-gas generator. The downhole steamgas generator burns APG at the bottomhole in the combustion chamber, and the combustion products - nitrogen and carbon dioxide - are supplied to the oil reservoir. A method for calculating the theoretical amount of air and combustion products is proposed.


Author(s):  
Dr. Mohamed A. GH. Abdalsadig

As worldwide energy demand continues to grow, oil and gas fields have spent hundreds of billions of dollars to build the substructures of smart fields. Management of smart fields requires integrating knowledge and methods in order to automatically and autonomously handle a great frequency of real-time information streams gathered from those wells. Furthermore, oil businesses movement towards enhancing everyday production skills to meet global energy demands signifies the importance of adapting to the latest smart tools that assist them in running their daily work. A laboratory experiment was carried out to evaluate gas lift wells performance under realistic operations in determining reservoir pressure, production operation point, injection gas pressure, port size, and the influence of injection pressure on well performance. Lab VIEW software was used to determine gas passage through the Smart Gas Lift valve (SGL) for the real-time data gathering. The results showed that the wellhead pressure has a large influence on the gas lift performance and showed that the utilized smart gas lift valve can be used to enhanced gas Lift performance by regulating gas injection from down hole.


2011 ◽  
Vol 133 (04) ◽  
pp. 52-52
Author(s):  
Rainer Kurz

This article discusses the importance of gas turbines, centrifugal compressors and pumps, and other turbomachines in processes that bring natural gas to the end users. To be useful, the natural gas coming from a large number of small wells has to be gathered. This process requires compression of the gas in several stages, before it is processed in a gas plant, where contaminants and heavier hydrocarbons are stripped from the gas. From the gas plant, the gas is recompressed and fed into a pipeline. In all these compression processes, centrifugal gas compressors driven by industrial gas turbines or electric motors play an important role. Turbomachines are used in a variety of applications for the production of oil and associated gas. For example, gas turbine generator sets often provide electrical power for offshore platforms or remote oil and gas fields. Offshore platforms have a large electrical demand, often requiring multiple large gas turbine generator sets. Similarly, centrifugal gas compressors, driven by gas turbines or by electric motors are the benchmark products to pump gas through pipelines, anywhere in the world.


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