Structural Integrity System Based on an Object-Oriented Activity- and Product Model

1993 ◽  
Author(s):  
Morten Lovstad ◽  
Tor G. Syvertsen
Keyword(s):  
Computational Models ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Physical Structure ◽  
Gas Production ◽  
Structural Safety ◽  
Actual State ◽  
Product Model ◽  
The North ◽  
Analysis Models

Abstract Huge steel or reinforced concrete structures in deep waters support the installations for oil and gas production in the North Sea. Steady operations in a hostile environment require that structural safety and integrity is maintained. For rapid evaluation and assessment of structural integrity in case of modifications or urgency situations, Structural Integrity Systems are established, comprising computational models and structural analysis programs. A major problem for structural assessment at short notice is to keep the analysis models updated and consistent with the actual state of the physical structure and the loadings. This paper proposes a layered approach for model integration, which enable maintenance of the models at a high level, from which detailed analysis models are derived in a consistent manner.

Synrift evaporite deposition and structural characterization of the onshore Alagoas subbasin

2019 ◽  
Vol 7 (4) ◽  
pp. SH19-SH31
Author(s):  
Gabriela Salomão Martins ◽  
Webster Ueipass Mohriak ◽  
Nivaldo Destro
Keyword(s):  
Structural Characterization ◽  
Oil And Gas ◽  
Hanging Wall ◽  
Structural Evolution ◽  
Gas Production ◽  
North East ◽  
The North ◽  
Half Graben ◽  
Well Data

The Sergipe-Alagoas Basin, situated in the north-east Brazilian margin, has a long tradition of oil and gas production and the presence and distribution of evaporites play an important role in petroleum systems in the basin. However, little research has focused on the structural evolution of the older, synrift evaporitic sections of the basin. We have focused explicitly in the detailed subsurface structural characterization of the rift in the Alagoas subbasin and the distribution of the Early Aptian evaporites. To accomplish this objective, we interpreted selected 2D and 3D seismic and well data located in two areas known as the Varela Low (VL) and Fazenda Guindaste Low (FGL). We identified diverse deformation styles in those two basin depocenters. Our interpretation indicates that VL consists of a half-graben with a significant rollover structure, controlled by two listric northeast–southwest border faults. The deformation in the hanging wall is also accommodated by release faults and minor antithetic faults. In this depocenter, we mapped in the seismic and the well data an older evaporitic sequence within the Coqueiro Seco Fm., known as Horizonte Salt. This evaporitic section occurs in the internal part of the VL half graben, where it is limited by release and antithetic faults. Significant salt strata growing toward the antithetic fault is observed. Whereas, the FGL represents a graben elongated along the north-east direction and is controlled by several types of structures. We recognized normal synthetic and antithetic faults, transfer zones, release faults, and rollover anticlines in the seismic throughout this depocenter. We mapped an evaporitic section within the Maceió Fm., known as Paripueira Salt, which consists of disconnected salt bodies, restricted to the hanging walls of synrift faults.

Development of semi-submersible production vessels and its application to Australian waters

2008 ◽  
Vol 48 (1) ◽  
pp. 241
Author(s):  
Hilde Engelsen ◽  
Henrik Hannus
Keyword(s):  
North Sea ◽  
Environmental Conditions ◽  
Oil And Gas ◽  
Gas Production ◽  
Oil And Gas Production ◽  
The North ◽  
Hull Design ◽  
Steel Catenary Risers ◽  
Drilling Rigs ◽  
In The Beginning

Semi-submersible platforms have a long history in the North Sea. In the beginning they were used mainly as mobile offshore drilling units, but in the last two decades the permanently moored semi-submersible production vessels have become widely used both as gas processing units and combination oil and gas production vessels. The design of production semi-submersibles evolved from that of drilling rigs, but there have since been significant improvements to the design of the hull and the topside configuration in relation to operational requirements and construction processes. The design methods have also been successfully adapted to areas with different environmental conditions, in combination with steel catenary risers and polyester mooring systems. On recent designs, simplifications of the hull systems are being implemented, which ease operation and enhance the passive safety. Finally, the semi-submersible production vessel’s application to Australian waters is discussed with focus on topside layout, hull design and mooring system design. Environmental conditions offshore northwest Australia are compared to North Sea and Gulf of Mexico conditions, along with vessel class and regulatory requirements.

On Determination of Acceptable Safety Class in Design of Pipe-In-Pipe (PIP) Systems

2014 ◽  
Author(s):  
Soheil Manouchehri ◽  
Guillaume Hardouin ◽  
David Kaye ◽  
Jason Potter
Keyword(s):  
Failure Modes ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Gas Production ◽  
Point Of View ◽  
Insulation Material ◽  
Limit States ◽  
Oil And Gas Production ◽  
Operational Conditions ◽  
Outer Pipe

Pipe-In-Pipe (PIP) systems are increasingly used in subsea oil and gas production where a low Overall Heat Transfer Coefficient (OHTC) is required. A PIP system is primarily composed of an insulated inner pipe which carries the production fluid and an outer pipe that protects the insulation material from the seawater environment. This provides a dry environment within the annulus and therefore allows the use of high quality dry insulation system. In addition, from a safety point of view, it provides additional structural integrity and a protective barrier which safeguards the pipeline from loss of containment to the environment. Genesis has designed a number of PIP systems in accordance with the recognized subsea pipeline design codes including DNV-OS-F101 [1]. In section 13 F100 of the 2013 revision, a short section has been included in which PIP systems are discussed and overall design requirements for such systems are provided. It has also been stated that the inner and outer pipes need to have the same Safety Class (SC) unless it can be documented otherwise. This paper looks at the selection of appropriate SC for the outer pipe in a design of PIP systems based on an assessment of different limit states, associated failure modes and consequences. Firstly, the fundamentals of selecting an acceptable SC for a PIP system are discussed. Then, different limit states and most probable failure modes that might occur under operational conditions are examined (in accordance with the requirements of [1]) and conclusions are presented and discussed. It is concluded that the SC of the outer pipe of a PIP system may be lower than that of the inner pipe, depending on the failure mode and approach adopted by the designer.

scholarly journals Late Cretaceous basin development of the southern Danish Central Graben

1969 ◽  
Vol 20 ◽  
pp. 15-18
Author(s):  
Finn Jakobsen ◽  
Claus Andersen
Keyword(s):  
Late Cretaceous ◽  
Oil And Gas ◽  
Seismic Inversion ◽  
Gas Production ◽  
Structural Development ◽  
Oil Accumulation ◽  
Oil And Gas Production ◽  
North West ◽  
The North ◽  
Basin Development

The Danish oil and gas production mainly comes from fields with chalk reservoirs of Late Cretaceous (Maastrichtian) and early Paleocene (Danian) ages located in the southern part of the Danish Central Graben in the North Sea. The area is mature with respect to exploration with most chalk fields located in structural traps known since the 1970s. However, the discovery by Mærsk Oil and Gas A/S of the large nonstructurally and dynamically trapped oil accumulation of the Halfdan Field in 1999 north-west of the Dan Field (e.g. Albrechtsen et al. 2001) triggered renewed exploration interest. This led to acquisition of new high quality 3-D seismic data that considerably enhanced imaging of different depositional features within the Chalk Group. Parallel to the endeavours by the operator to locate additional non-structural traps in porous chalk, the Geological Survey of Denmark and Greenland took advantage of the new data to unravel basin development by combining 3-D seismic interpretation of a large number of seismic markers, well log correlations and 2-D seismic inversion for prediction of the distribution of porous intervals in the Chalk Group. Part of this study is presented by Abramovitz et al. (in press). In the present paper we focus on aspects of the general structural development during the Late Cretaceous as illustrated by semi-regional time-isochore maps. The Chalk Group has been divided into two seismically mappable units (a Cenomanian–Campanian lower Chalk Unit and a Maastrichtian–Danian upper Chalk Unit) separated by a distinct basin-wide unconformity.

scholarly journals Ecological risks during offshore construction of oil platforms

2020 ◽  
Vol 217 ◽  
pp. 04002
Author(s):  
Ksenia Derevtsova ◽  
Vladislav Ginevskii ◽  
Gleb Kataev ◽  
Semion Kim ◽  
Polina Veselova
Keyword(s):  
Natural Resources ◽  
Oil And Gas ◽  
Oil Pollution ◽  
Natural Habitat ◽  
Gas Production ◽  
The Arctic ◽  
Economic Activities ◽  
Arctic Seas ◽  
The North ◽  
Low Culture

The article tells about the risks of low-culture construction of oil facilities on the Arctic shelf. The long-term, practically neglected exploitation of the unique natural resources of the Russian North and the low culture of their development led in a number of its regions, including the waters of the Arctic seas with islands, to an emergency ecological situation - the partial and sometimes complete destruction of the fragile Arctic natural habitat of the small peoples of the North and the created cities and villages. Without proper environmental support, economic activities continue in the field of extraction, transportation and processing of natural resources. The progressive pollution of rivers and lakes leads to a qualitative depletion of water resources - a change in the composition of the waters of the Arctic Ocean. The danger of oil pollution of the marine environment is associated with plans for its production on the continental shelf of the Russian Federation. The oil and gas production complex in the Russian Arctic regions are being formed on the basis of already discovered fields and will develop as other promising fields are developed.

scholarly journals PROJECT PERFORMANCE AND MONITORING OF A REVETMENT, COCOS BAY, EAST TRINIDAD

2012 ◽  
Vol 1 (33) ◽  
pp. 38
Author(s):  
Charmaine O'Brien-Delpesh ◽  
Candice Gray-Bernard ◽  
Marisha Tang-Kai
Keyword(s):  
Structural Integrity ◽  
Oil And Gas ◽  
Wave Climate ◽  
Winter Period ◽  
Coastal Evolution ◽  
Suitable Material ◽  
The North ◽  
Three Phase ◽  
Severe Erosion ◽  
Actual Response

The eastern shoreline of Trinidad has been suffering extensively from erosion over the years. This coast is exposed to the Atlantic Ocean and is subjected to large swells especially during the North Atlantic winter period, storms and hurricanes. The coastal area of Cocos Bay located on the east coast of Trinidad between the Nariva and Ortoire Rivers has been undergoing severe erosion at a rate of approximately 0.5 m to 1.7 m per year. In 2005, the Ministry of Works and Transport, Drainage Division started the construction of a 2.3 km long rubble revetment (rip rap) which was completed in 2008. The function of the revetment was to control erosion and flooding thereby protecting the Manzanilla-Mayaro Road which is a major artery linking the oil and gas sector as well as several coastal villages. This revetment formed the emergency intervention phase of a three phase solution recommended along the South Cocos Bay. Conforming to the Certificate of Environmental Clearance (CEC), the Ministry of Works and Transport, Drainage Division has been monitoring the possible impacts of the structure on the beach environment from post construction to present and its structural integrity. During the last five years, the monitoring study has revealed that in the vicinity of the revetment, erosion and flooding have been mitigated; however there has been narrowing of the beach even though the gradient has remained the same. Flanking has also been observed immediately north and south of the revetment. In regards to the structural integrity of the revetment, the armour layer which was constructed using local rock (blue limestone), 200 - 300 kg is showing signs of weathering and shearing. This has resulted in voids in the armour layer which has exposed the filter and underlayers. It is recommended that in order to maintain the functionality and structural integrity over a design life of 25 years, the armour layer be repaired with a suitable material which has historically been sourced externally. The post documents the prevailing wave climate, previous coastal evolution modelling, and the pre and post construction profile records. The shoreline response to the revetment is predicted using GENESIS and compared to the actual response based on an analysis of the beach profile monitoring records are also presented.

Accounting for Natural Crack Growth Shapes During Environmental Cracking

2012 ◽  
Author(s):  
Do-Jun Shim ◽  
Fredrick Brust ◽  
Gery Wilkowski
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Growth ◽  
Growth Analysis ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Gas Production ◽  
Oil And Gas Production ◽  
Growth Method

Environmental cracking, such as stress-corrosion cracking (SCC), is a significant issue for a variety of industries, such as those dealing with power generation — nuclear, oil and gas production, and pipeline transmission, etc. SCC is particularly of concern in that catastrophic failures can occur even at low applied stress levels (e.g., residual stress produced by welding). Thus, it is critical to evaluate the behavior of SCC for structural integrity assessments. In this paper, three different crack growth methods (i.e., idealized crack growth analysis, crack growth analysis using finite element alternating method; FEAM, and the natural crack growth method) are summarized. These methods all utilize the stress intensity factor for crack growth evaluations. Thus, these methods can be used for assessment of environmental cracking that is based on stress intensity factor. Various examples are shown in this paper to demonstrate the applicability of these methods. Comparisons of results obtained from different methods are also provided in this paper.

scholarly journals Methane emissions from oil and gas platforms in the North Sea

2019 ◽  
Vol 19 (15) ◽  
pp. 9787-9796 ◽  
Author(s):  
Stuart N. Riddick ◽  
Denise L. Mauzerall ◽  
Michael Celia ◽  
Neil R. P. Harris ◽  
Grant Allen ◽  
...  
Keyword(s):  
North Sea ◽  
Oil And Gas ◽  
Meteorological Data ◽  
Gas Production ◽  
Normal Operation ◽  
Emission Inventories ◽  
The North ◽  
The North Sea ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Abstract. Since 1850 the concentration of atmospheric methane (CH4), a potent greenhouse gas, has more than doubled. Recent studies suggest that emission inventories may be missing sources and underestimating emissions. To investigate whether offshore oil and gas platforms leak CH4 during normal operation, we measured CH4 mole fractions around eight oil and gas production platforms in the North Sea which were neither flaring gas nor offloading oil. We use the measurements from summer 2017, along with meteorological data, in a Gaussian plume model to estimate CH4 emissions from each platform. We find CH4 mole fractions of between 11 and 370 ppb above background concentrations downwind of the platforms measured, corresponding to a median CH4 emission of 6.8 g CH4 s−1 for each platform, with a range of 2.9 to 22.3 g CH4 s−1. When matched to production records, during our measurements individual platforms lost between 0.04 % and 1.4 % of gas produced with a median loss of 0.23 %. When the measured platforms are considered collectively (i.e. the sum of platforms' emission fluxes weighted by the sum of the platforms' production), we estimate the CH4 loss to be 0.19 % of gas production. These estimates are substantially higher than the emissions most recently reported to the National Atmospheric Emission Inventory (NAEI) for total CH4 loss from United Kingdom platforms in the North Sea. The NAEI reports CH4 losses from the offshore oil and gas platforms we measured to be 0.13 % of gas production, with most of their emissions coming from gas flaring and offshore oil loading, neither of which was taking place at the time of our measurements. All oil and gas platforms we observed were found to leak CH4 during normal operation, and much of this leakage has not been included in UK emission inventories. Further research is required to accurately determine total CH4 leakage from all offshore oil and gas operations and to properly include the leakage in national and international emission inventories.

WESTERN AUSTRALIA—A TECHNOLOGY BASE FOR THE OIL AND GAS INDUSTRY

2001 ◽  
Vol 41 (1) ◽  
pp. 777
Author(s):  
B.F Ronalds
Keyword(s):  
Oil And Gas ◽  
Local Environment ◽  
Oil And Gas Industry ◽  
Gas Production ◽  
Gas Industry ◽  
Oil And Gas Production ◽  
North West ◽  
The North ◽  
International Industry ◽  
Analytical Tools

Oil and gas production is characterised by a truly international industry, and yet a unique local environment. Solutions developed elsewhere cannot always be imported directly for Australian use. For this reason alone, a strong local technology base is of value to the Australian oil and gas industry. Other benefits include the ability to provide high quality education and training for people entering, and already in, the industry.A case study is described where the Western Australian technology base is facilitating solutions to a specific challenge faced on the North West Shelf (NWS); namely, that the criteria for reliable development and operation of its offshore infrastructure for oil and gas production are more severe than other petroleum provinces, requiring new analytical tools to be developed.

Dynamic Behaviour of Compliant Towers in Deep Sea

2003 ◽  
Author(s):  
Gu¨nther F. Clauss ◽  
June Young Lee
Keyword(s):  
Deep Water ◽  
Oil And Gas ◽  
Wave Structure ◽  
Nonlinear Effects ◽  
Gas Production ◽  
Program System ◽  
Period Range ◽  
Structure Interaction ◽  
Viscous Forces ◽  
The North

For oil and gas production in deep water (> 500m) compliant structures are designed. By dedicated reduction of stiffness and optimization of mass (including added mass contributions) the fundamental period is tuned to about 30s, which is well above the period range of significant wave energy. This paper presents the results of a comprehensive numerical analysis of the hydroelastic behaviour of compliant towers in deep water, investigating the dynamic response of a flexible structure in a given sea state. The numerical program system is based on ADINA with an integrated hydrodynamic module for wave/structure interaction. Nonlinear effects of viscous forces are considered using Morison’s vector equation. In addition nonlinear characteristics of soil/structure interaction are also included according to API regulations. At first, for verification of the program system, the numerical results of a monotower are compared to analytical solutions obtained by modal analysis of the structure in regular and irregular seas. Based on the validated program a compliant tower installed in 503 m water in the Gulf of Mexico (Baldpate tower) is modeled in 3D, and the characteristic dynamic behavior is evaluated. Finally, the tower is exposed to a real “freak” wave (the 25.6m high New Year Wave which has been registered at the North Sea Draupner platform on January 1, 1995), and the associated loads and motions are evaluated.

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