Aspects of the Offshore Oil and Gas Industry

 

7 April 2011 North of England Branch Technical Seminar and Dinner Cruise

Sponsored by Wellstream

 

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Overview

The North of England Branch of the SUT ran a seminar which aimed to provide a background to the breadth of the offshore oil and gas industry. The North of England is home to a number of major suppliers to this industry, and the seminar was designed to provide the context in which these companies operate. In other words, it was intended to help engineers working in one area to appreciate where their product fits into the broader picture. The talks were aimed primarily at students, new graduates and engineers who want to broaden their knowledge, but was also intended to be of interest to more experienced engineers, and as well as provide an informative backdrop for non-engineers who work in the industry.

The social evening followed the seminar and provided an opportunity for those who work in the offshore oil and gas industry, or in any other underwater industry, to mix in an informal atmosphere, and to enjoy a social drink and a fish supper.

 

Presentations

Life Extension of Subsea Structures

Dr Afshin Motarjemi, Xodus Group

 

Geology of Hydrocarbon Exploration

Dr Kuncho Kurtev, Newcastle University

 

 

Materials in Harsh Environments

 

23 March 2011 North of England Branch Evening Meeting

Chairman Terry Sheldrake, Wellstream International Ltd

Sponsored by Bridon International Ltd and SpanSet

 

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Presentations

Metals in Extreme Conditions

Richard Clements, Wellstream International Ltd

Never before has it been more important to understand the materials we are using in deepwater developments. The failure of components or systems installed in subsea oilfield developments carries with it implications for the environment, health and safety and corporate reputation, as seen recently in the Macondo incident in the GOM. Learning from problems with materials and proper, thorough testing and qualification play a vital role in this process, ensuring materials are suitable for the applications into which they are being put. This presentation focused on qualification and testing methodologies for metallic materials in flexible pipes for ultra-deep-water applications, the problems which can be encountered during those qualifications, and an example of an investigation into an issue raised by a client – vent valve screen corrosion.

 

The use of Fibre Ropes in the Marine and Offshore Industries

James Mackay, Bridon International Ltd

This presentation looked at materials, properties and focuses on the varied applications we now see high strength fibre ropes being used.

 

Pipeline Replacement Project

 

17 March 2011 London Evening Meeting

Chairman Dr Bob Allwood, Chief Executive, SUT

Sponsored by Flexlife

 

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Overview

In early January 2011, the 14" flowline between Forties Bravo (FB) and Forties Charlie (FC) platforms developed a leak in the vicinity of the FC platform. Several repairs were undertaken, however, new leaks occurred in the line at each pressure test after repairs. It was decided to cut out and remove a 10m section of the line for further examination and analysis to determine the cause of its failure. On removing this section, a Smart flanged section was put in its place. Unfortunately during the pressure test new failures were identified and it was therefore decided to retire the line altogether.

In order to mitigate both valuable production and associated financial losses, a decision was taken to provide a temporary connection between FB and FC, by re-routing the currently existing 8” produced water flexible injection line (PWRI) also running between FB and FC, which allowed for re-instatement of hydrocarbon transport. This work was extremely fast track and production was restored by using this measure on 6th March 2011.

A number of options were considered for the permanent line replacement. It was concluded that the temporary connection will be replaced by a permanent, trenched and buried 14” flexible pipeline, the design of which has already been approved; its fabrication and installation to be executed over the next 4 to 6 months.

 

Presentations

Apache Forties – Bravo to Charlie Pipeline Replacement Project and Interim Production through PWRI

The evening’s presentation was split into two portions. The first section presents the interim findings of the materials and corrosion examination and analysis including photographic evidence showing the failure modes in the line. This was presented by David Newman, Flexlife Asset Integrity Manager.

Following on from this, a presentation detailing the subsea campaigns since early January 2011 culminating in the novel rerouting of the produced water line (PWRI) and its connection into the Bravo – Charlie system was given by Paul Williams who is a Project Manager with Flexlife and was directly responsible for these works.

 

Subsea Solutions for Arctic in Extreme Weather Environments

 

9 March 2011 Aberdeen Branch Evening Meeting

Chairman Adrian Phillips

 

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Overview

Excitement continues to grow around the prospects of major exploration and development in and around the arctic continental shelf. Russian gas giant Gazprom is voicing optimism about the prospects for a final investment decision this year in favour of the landmark Shtokman gas and liquefied natural gas development in the Barents Sea. The Shtokman offshore field is a joint project controlled by Gazprom with France’s Total and Norway’s Statoil as minority shareholders. The other major Russian player Rosneft is already talking to "global players" about exploration ventures in Russia’s Barents Sea and the Asian part of Russia’s Arctic waters. This follows major joint ventures signed last month to explore in the Arctic’s South Kara Sea with BP and in the Black Sea with ExxonMobil.

 

Presentations

Subsea Arctic Pipelines: Key to Successful Field Developments

Glenn Lanan, Intecsea

Hydrocarbon transportation is one of the controlling requirements for offshore Arctic field development and pipelines are often required for intrafield flowlines, export to shore-based facilities or for tanker loading systems. The offshore Arctic environmental and loading conditions provide unique challenges for conventional subsea pipeline technology. INTECSEA summarised the increasing industry experience with pipeline design, construction and operation in ice covered waters and highlighted some of the remaining challenges such as optimised design for ice loadings and subsea leak detection.

 

ENI Goliat Subsea Development

Richard Carter, Aker Solutions

Following Statoil’s pioneering and record breaking subsea project, Snohvit, the next major subsea development in the same area is ENI’s Goliat. Statoil opted for a 140km "long offset", whilst ENI have chosen for an FPSO. Aker Solutions provided some insights on the reason for the decision whilst offering a perspective on the engineering challenges of the subsea solution.

 

Recent Advances in Satellite Remote Sensing for Ice Monitoring

Nicholas Walker, eOsphere

Satellite remote sensing can provide useful information for operators working in ice infested waters, including information about ice extent, ice type, ice motion and icebergs. Recent advances in satellite SAR technology allow additional information to be extracted for successful ice monitoring. These new capabilities include improved resolutions, improved polarimetric and radar frequency options.

 

Geophysics and Geohazards – Defining Subsea Engineering Risk

 

24 February 2011 Joint SUT and ASEG International Seminar, Subsea Australasia Conference 2011,

Perth, Australia

 

Report

‘Geophysics and Geohazards – Defining Subsea Engineering Risk’, a joint SUT and ASEG one-day seminar, was held in Perth on the 24th February 2011 as part of the Australasian Oil and Gas (AOG) Exhibition and Conference. An almost full house ensured this second conference, which first took place in March 2010, was truly successful.

After the usual formalities including the thanks to Fugro as the principal sponsor, Dan McConnell, VP Marine Consulting, AOA Geophysics, gave the keynote presentation, ‘On Marine Seep Hunting for Oil and Gas Exploration’. The use of a combination of multibeam echo sounder bathymetry and backscatter data with accurately placed piston cores at the seep sites to directly sample a petroleum system was described. An astounding 46% of the targets showed unambiguous thermogenic gas and 13% showed evidence of migrated liquid petroleum.

Stephen Wardlaw, Business Development Consultant, Fugro Geoconsulting Pte Ltd, then described how autonomous underwater vehicles (AUVs) are now routinely utilised in deepwater site investigations for oilfield developments. Drawing on examples, Stephen’s paper reviewed the contribution from the various AUV instruments, and discussed techniques currently used in AUV data integration in the assessment of engineering geohazards.

The use of marine resistivity surveys on dredging projects, and cable and pipe route surveys to assist in port design and alluvial mining projects was described by Dr Ir Peteralv Brabers, General Manager, Demco NV (Belgium). Dr Ir Brabers provided an insight into the theory of resistivity principles and a brief comparison between acoustic methods and marine geo-electric methods.

After the morning tea and coffee break, Dr Ouzani Bachir, Geoscientist, Offshore Geo-Survey Sdn Bhd, discussed deepwater geohazards characterisation. Unlike the continental shelf where geohazards are well documented and site investigation methods are established, deepwater environments are unfamiliar and lack well logs and borehole data. The use of seismic inversion and amplitude versus offset (AVO) analysis for shallow water flows and gas hydrates assessments was discussed.

Dan McConnell returned to the podium to describe his involvement in the DOE-Chevron Joint Industry Gas Hydrate Project in the Gulf of Mexico, 2009 (Leg II). The three-week, $11.5m expedition drilled seven logging-while-drilling (LWD) holes at three sites that tested a variety of geologic/geophysical models for the occurrence of gas hydrate in sand reservoirs in the deepwater Gulf of Mexico.

The lunch break and an opportunity to visit the exhibition was followed by a description by Bachir Ouzani on how the iCUBE 3D volumes converted from 2D seismic lines shot at 50–500m spacing provide increased data density and allowed improved lateral geological continuity and definition of geological structures.

Dr Steve Tyler, Principal Geophysicist, Fugro Survey Pty Ltd, then described how data from a geohazard and environmental baseline survey within the Bonaparte Basin confirmed a barrier reef complex extended from the Sahul Platform through to the Ashmore reef area approximately 18 000 years ago. The geophysical data highlighted the structural complexity of this area with a significant number of pockmarks identified around the flanks of these outcropping palaeo-reefs.

A system of faults extending along the west coast and up to the North West Shelf was described by James Hengesh, Research Fellow, University of Western Australia (UWA). A magnitude 7.3 earthquake, the largest in Australia’s history, occurred along one of these faults, and other faults have the potential to produce similar large magnitude events. Work is underway at UWA to better understand the hazard posed by these faults and to incorporate them in future seismic hazard assessments for major infrastructure projects in Western Australia.

Dr Douglas Bergersen, CEO/Geophysicist, Acoustic Imaging, described the oil and gas industry desire to standardise the presentation of baseline marine survey data for better long- term management of information across offshore development areas. One such template for the storage of information is the Seabed Survey Data Model (SSDM) based around the ArcGIS geodatabase structure. Dr Bergersen’s paper presented an overview of the integration to date and discussed how software tools may be used to assist and optimise the identification, characterisation and quantification of marine geohazards. The seamless transfer of information to the SSDM was illustrated with a case example from the North West Shelf of Australia.