A Concept Design and Hydrodynamic Behavior of a Spar Platform

2003 ◽  
Author(s):  
Marcio de Abreu Grove ◽  
Carlos Antonio Levi da Conceic¸a˜o ◽  
Richard David Schachter
Keyword(s):  
Design Method ◽  
Low Frequency ◽  
Vertical Motion ◽  
Concept Design ◽  
Hydrodynamic Behavior ◽  
Spar Platform ◽  
The North ◽  
Campos Basin ◽  
The North Sea ◽  
And Storage

This paper presents a study of a Production and Storage Spar Platform concept design for operations in deep water, under the environmental conditions of the Campos Basin, Brazil. This study is the result of a research sponsored by Ageˆncia Nacional do Petro´leo – ANP. The theme was chosen due the good results obtained by this kind of platform in the North Sea and the Gulf of Mexico. Since the exploration of hydrocarbonets is moving to deeper waters, where the Spar concept seems to be one of the best options for the task, due to its simplicity in construction and operation. Although it looks simple, this work had required perceptive studies, and the best way chosen to carry it out, was dividing it in two directions: one dealing with the design method and naval architecture aspects and other with its hydrodynamic behavior. The first line took into consideration the hull generation, compartmentation, weight distribution and stability. A design methodology is presented and the interaction of these factors are showed, taking into account the hydrodynamic results. The second line has favored the evaluation and the control of the vertical motion, excited by dominant waves from the spectra of energy of the sea, and the horizontal motions due the low frequency excitations, and its interaction with the mooring system.

Offshore field trial application of low-frequency passive microseismic technology in the North Sea for exploration, appraisal and development of hydrocarbon deposits

First Break ◽  
2021 ◽  
Vol 39 (4) ◽  
pp. 45-50
Author(s):  
Vasilii Ryzhov ◽  
Dmitrii Ryzhov ◽  
Ilshat Sharapov ◽  
Sergey Feofilov ◽  
Evgeny Smirnov ◽  
...  
Keyword(s):  
North Sea ◽  
Field Trial ◽  
Low Frequency ◽  
The North ◽  
The North Sea ◽  
Offshore Field ◽  
Hydrocarbon Deposits

Frequency-dependent velocity analysis and offset-dependent low-frequency amplitude anomalies from hydrocarbon-bearing reservoirs in the southern North Sea, Norwegian sector

Geophysics ◽  
2017 ◽  
Vol 82 (6) ◽  
pp. N51-N60 ◽  
Author(s):  
Sayyid Suhail Ahmad ◽  
R. James Brown ◽  
Alejandro Escalona ◽  
Børge O. Rosland
Keyword(s):  
North Sea ◽  
High Frequency ◽  
Spectral Decomposition ◽  
Low Frequency ◽  
Velocity Analysis ◽  
Frequency Dependent ◽  
Lower Velocity ◽  
The North ◽  
Significant Difference ◽  
The North Sea

Our aim was to identify some of the characteristics of low-frequency anomalies. Specifically, we have looked, in 3D broadband data from the North Sea, for any offset dependence in these anomalies and any frequency-related change in normal moveout (NMO) velocity that could influence stacking power over different frequencies. After high-resolution spectral decomposition, two types of low-frequency anomaly have been identified associated with hydrocarbon-bearing reservoirs: (1) at the reservoir top and (2) below the reservoir, with a time delay of approximately 100–200 ms. Both types of anomalies indicate offset dependence. On the near-offset stacks, they are relatively strong, but they tend to be absent on the far-offset stacks. In addition, horizon velocity analysis, which was performed along the horizons picked at the tops of reservoir and nonreservoir intervals, has revealed frequency-dependent NMO velocity. For nonreservoir events, we found no significant difference between the NMO velocities for the low-frequency and high-frequency filtered common-midpoint gathers. However, along the anomalously low-frequency events observed at the tops of, and below, oil-bearing reservoirs, lower velocity is observed for low-frequency and higher velocity for high-frequency filtered gathers. If these properties turn out to be universally typical, increased understanding and inclusion of them could lead to improved workflows and help increase the reliability of low-frequency analysis as a hydrocarbon indicator.

scholarly journals Decommissioning Plans for Fixed Offshore Platforms: A Brief Revision

2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Marcio Soares Pinheiro ◽  
Paulo Roberto Duailibe Monteiro
Keyword(s):  
North Sea ◽  
Rio De Janeiro ◽  
The State ◽  
Oil Field ◽  
Offshore Platforms ◽  
The North ◽  
Campos Basin ◽  
Heavy Lift ◽  
Long Time ◽  
The North Sea

Brazil began to explore its seas in the 60’s of the XX Century looking for petroleum. This journey began in the Northeast and the first oil field produced offshore was the Guaricema Field, in the State of Sergipe. During the 70’s, Petrobrás found oil in the Campos Basin, between the States of Espírito Santo and Rio de Janeiro, that became the most important oil province in Brazil until the discovery of the Pre-Salt province, in the Santos Basin. As these fields are producing for a long time, many of them are already completely depleted or their production is in way of to be not commercial anymore, and their facilities need to be decommissioned. This review of decommissioning practices of fixed offshore platforms carried out worldwide has focus on the removal of topside with special vessels designed for this purpose or with conventional methods (crane vessels + barge). It will show the benefits of using specialised heavy lift vessels to remove the topsides and move it to shore for dismantling / recycling / reuse / disposal. The cases for study were the successful decommissioning projects in the North Sea: Brent B/D, Valhall QP, Viking, Curlew, Eider A, Golden Eye and Leman, Iwaki-Oki, Halfweg Q1, Yme and Ninian North.

Concept, Design and Implementation of a Halite Scale Mitigation Completion in a Gas Well

2014 ◽  
Author(s):  
Doug Maxwell ◽  
Keith Young
Keyword(s):  
Delivery System ◽  
North Sea ◽  
Project Team ◽  
Concept Design ◽  
Water Delivery ◽  
Practical Application ◽  
Gas Well ◽  
The North ◽  
The North Sea ◽  
Risk Review

Abstract A North Sea operator was planning to sidetrack an existing gas well to access untapped reserves with an extended reach, sub-horizontal reservoir target. The well was expected to deposit halite scale in the lower part of the completion and across the sandface based on experience from other wells in the field and a production chemistry desk study, possibly from initial production. The project team investigated completion concepts for the well that would address the scaling issue and selected the most appropriate concept prior to designing and planning a practical installation. Several concepts were examined for practical application, including a detailed risk review, before a capillary water delivery system was selected. This involved running 3 capillary lines through the production packer to chemical injection valves deployed on a pre-perforated tailpipe inside the lower completion. As this lower completion was a 5” perforated liner, significant tolerance challenges had to be overcome. The well was completed with the selected concept in January 2013, with the water delivery system injecting 8 bbls of water per day from initial production. The well is on stream and producing at higher than expected rates, with no halite scaling issues identified. By identifying potential flow assurance issues at the concept stage, innovative applications of existing technology can be considered and applied. A multidisciplinary project team is required to meet the demands of such a challenging project. With halite scaling becoming increasingly problematic in the North Sea, the application of water delivery completion concepts may become key to future developments.

On-Board Monitoring, Analysis and Decision Support During Offshore Pipe Lay Operation

2011 ◽  
Author(s):  
Joakim Taby ◽  
Ole David O̸kland ◽  
Egil Giertsen ◽  
Naiquan Ye ◽  
Melvyn Morgan ◽  
...  
Keyword(s):  
Field Tests ◽  
Lateral Stability ◽  
Current Profile ◽  
Tension Development ◽  
Additional Information ◽  
The North ◽  
Board Monitoring ◽  
The North Sea ◽  
Gps System ◽  
And Storage

For pipe lay operations parameters like heading and position of the lay vessel are available from the GPS system on the vessel. In some cases the current profile may also be monitored. Provided that a fast and robust numerical tool is available and can be integrated with the on-board system, the above parameters and a measure of tension in the pipe will be sufficient to simulate the appurtenant static configuration of the catenary and visualize it online during the lay operation. Such a system will provide valuable additional information such as: catenary shape including stresses in the pipe, lay tension, development of free spans, and lateral stability during installation. In the period April-August 2009 two field tests of the developed system were performed. Both field tests were related to Acergy installation campaigns for the Ormen Lange Phase II development in the North Sea; 1) ∼13 km infield MEG (IMEGDA) installation by Acergy Falcon, and 2) ∼13km infield umbilical (IUMB-DA) installation by Acergy Eagle (both at ∼860m water depth). In this paper the experiences from the field tests are discussed. This includes assessment of on-board data collection and storage of key parameters during installation, real-time online 3D finite element (FE) analysis and satellite link to shore for support during installation. The accuracy of the results obtained in the on-board monitoring system is assessed by comparison to available as-laid survey information.

Risk Assessment of Production and Storage Tankers

1996 ◽  
Vol 118 (3) ◽  
pp. 198-203
Author(s):  
J. E. Vinnem ◽  
S. Haugen ◽  
R. Bo̸rresen
Keyword(s):  
Oil And Gas ◽  
Feasible Solution ◽  
System Protection ◽  
The North ◽  
Oil And Gas Fields ◽  
The North Sea ◽  
Safety Features ◽  
Favorable Safety ◽  
Gas Fields ◽  
And Storage

Production and storage tankers are being evaluated extensively for development of marginal oil and gas fields in the North Sea. The main safety aspects of these vessels are discussed, based on a number of quantitative risk assessments for these vessel concepts. These studies have confirmed the importance of several important safety features, such as a fire-protected, enclosed escape way along one of the sides of the ship. Other important safety features include weather-vaning capability as a function of the turret location, location and configuration of the flare system, protection of cargo tanks by inert gas blanketing, as well as procedures for strict control of tank intervention. The results, show that the production and storage vessels have favorable safety characteristics, and that these concepts represent an acceptable and feasible solution for the marginal fields.

Leveling aerogeophysical data using a moving differential median filter

Geophysics ◽  
2006 ◽  
Vol 71 (1) ◽  
pp. L5-L11 ◽  
Author(s):  
Eirik Mauring ◽  
Ola Kihle
Keyword(s):  
Median Filter ◽  
Low Frequency ◽  
Data Sets ◽  
The North ◽  
Level Data ◽  
The North Sea ◽  
Helicopter Survey ◽  
A New Technique ◽  
Line Level ◽  
Tie Line

We describe a new technique that can be used to level data collected along regular and irregular line patterns with or without tie-line control. The technique incorporates a moving differential median filter to minimize line-level errors, to level survey-line data, and to microlevel data with no tie-line control. This overcomes the problem of standard leveling methods that lose their effectiveness with irregular flight patterns. To validate the method, we use it to level very-low-frequency (VLF) electromagnetic (EM) data from a helicopter survey where flight lines are parallel. Leveling is also performed on a set of vintage aeromagnetic data from the North Sea, gathered from nonparallel flight lines. Results show that the differential median filter leveling technique is superior to the standard leveling method because it results in fewer line errors and less distortion of high-wavenumber anomalies when processing irregular survey lines, making the method suitable for a wide variety of data sets.

Classification, Treatment and Storage of Low Specific Activity Radioactive Waste From the Petroleum Industry

2001 ◽  
Author(s):  
Tore Ramsøy ◽  
Elisabeth Strålberg ◽  
Per Varskog
Keyword(s):  
Specific Activity ◽  
Petroleum Industry ◽  
Site Classification ◽  
Activity Levels ◽  
Simple Method ◽  
The North ◽  
The North Sea ◽  
Free Classification ◽  
And Storage

Abstract Low specific activity deposits containing 226Ra, 228Ra and their daughter isotopes is a well-known problem in the petroleum industry. It is estimated that installations in the Norwegian sector of the North Sea will generate from 50 to 75 tons of scale and sludge annually. A simple method for on-site classification of LSA scale has been developed. Classification of the sludge from the Brent Spar revealed that only a small fraction of the total amount of sludge exceeded the exemption level. Sludge classified to be below the free classification limit was incinerated with surveillance of activity levels in the ash and effluents.

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