Offshore

How to see what cannot be seen within a Disastrous, Highly Corroded Subsea Gas Pipeline during Repair and Pre- Commissioning Process

How to see what cannot be seen within a Disastrous, Highly Corroded Subsea Gas Pipeline during Repair and Pre- Commissioning Process
How to see what cannot be seen within a Disastrous, Highly Corroded Subsea Gas Pipeline during Repair and Pre- Commissioning Process
Repairing a subsea pipeline has its own special challenges. It goes from levelling the pipeline inner pressure with seabed pressure at depth of damage, to cutting the line, installation of smart flanges and spool pieces, and finally going through pre-commissioning steps and miscellaneous pigging operations. During all these steps, it is inevitable...

Innovative Solutions to Address Stabilization Challenges of a 48-Year Old Subsea Pipeline

Innovative Solutions to Address Stabilization Challenges of a 48-Year Old Subsea Pipeline
Innovative Solutions to Address Stabilization Challenges of a 48-Year Old Subsea Pipeline
Subsea pipelines are externally concrete coated to provide vertical and lateral stability. The loss of concrete can lead to floatation or lateral movement on the seabed. If seabed is hard/rocky, then lateral rubbing may lead to wall thinning at 6 o'clock and can result in a leak or flattening at the bottom affecting ovality. This paper presents...

Numerical prediction of material properties and structural response of JCO-E offshore pipes

University of Thessaly
University of Thessaly
The present paper presents the application of advanced finite element tools to predict the influence of cold-forming on material properties and collapse resistance of steel JCO-E pipes. Results are obtained for a thick-walled 30-inch-diameter pipe, corresponding to diameter-to-thickness ratio value less than 20. The numerical simulations are...

Offshore Pipelines and stability assessment of Submerged Slopes under Seismic Conditions

National Technical University of Athens
National Technical University of Athens
Depending on the prevailing bathymetrical and geotechnical conditions, the integrity of offshore pipelines is threatened by potential slope instabilities that occur at the seabed or at the bottom of lakes. In addition, submarine slides are more frequent in seismic regions. The instability of onshore slopes under seismic conditions is undoubtedly a...

Artificial Intelligence in the Design of Offshore Pipelines against Geohazards

National Technical University of Athens
National Technical University of Athens
Depending on the local site conditions (i.e. bathymetry, geomorphology, geology), an offshore geohazard may have a detrimental impact on an offshore high-pressure gas pipeline during its lifetime. This fact is more pronounced in areas characterized by seismicity and the associated earthquake-related geohazards. Therefore, the design of an offshore...

Safely repairing subsea flanges on flexible flowlines with a flexible bridging jumper structure

Safely repairing subsea flanges on flexible flowlines with a flexible bridging jumper structure
Safely repairing subsea flanges on flexible flowlines with a flexible bridging jumper structure
As offshore pipelines age, the oil and gas industry must properly maintain equipment to prevent leaks. In subsea flowlines, leaks sometimes originate from aging flanges. These flanges must be replaced. Historically, replacing the flange has required a lot of time. Different costly approaches are available, from subsea reparations to flowline...

Lessons Learned on 20 years of challenges to internal corrosion protection of subsea pipelines-corrosion inhibitor or pH stabilization?

Lessons Learned on 20 years of challenges to internal corrosion protection of subsea pipelines-corrosion inhibitor or pH stabilization?
Lessons Learned on 20 years of challenges to internal corrosion protection of subsea pipelines-corrosion inhibitor or pH stabilization?
The three phase fluid of the massive South Pars reservoir under the Persian Gulf, is transmitted 100Km to onshore facilities via numerous 32” API 5L pipelines. The wet sour fluid cont ains 0.5 mol% of H2S and 1.7 mol% of CO2 which forms a hostile environment to carbon steel. Hence, as per form er laboratory researches at design stag e in about 20...

Quantitative Pipeline Risk Assessment (QPiRATM) Fire and Dispersion Analysis of a Subsea Gas Pipeline Leak Using Empirical Consequence Modelling

Quantitative Pipeline Risk Assessment (QPiRATM) Fire and Dispersion Analysis of a Subsea Gas Pipeline Leak Using Empirical Consequence Modelling
Quantitative Pipeline Risk Assessment (QPiRATM) Fire and Dispersion Analysis of a Subsea Gas Pipeline Leak Using Empirical Consequence Modelling
A subsea pipeline transporting gas in Malaysia has a smal l leak at its subsea flange at 70m water depth, located 140m away from the processing platform. The flange has undergone three rectification works; however, the repair works were unsuccessful to achieve zero leak. A Quant itative Pipeline Risk Assessment (QPiRATM) fire and dispersion...

North Sea Wintershall Dea Case Study

North Sea Wintershall Dea Case Study
North Sea Wintershall Dea Case Study
Mittelplate is the largest oil field in Germany, located in the environmental ly sensitive Wadden Sea of the German State Schleswig-Holstein. An artificial Drilling and Production Island, named “Mitt elplate A” (MPA), was build early 1980`s on a tidal shoal and is operated by Wintershall Dea. In 2005, a 10 km, 10” stainless steel (1.4462 Duplex) p...

Cost-Effective Approach for Isolating/Decommissioning Offshore Sour Gas Pipelines

IPEC & Pipeline and Process Services
IPEC & Pipeline and Process Services
Safety is a crucial issue in operational activities. When performing a hot work operation on a live pipeline, it is very important to isolate the pipeline to prevent any dangerous event. In this paper, a newly and innovatively designed approach has been presented which has been used to isolate a 32” and an 18” offshore and infield pipelines from...

Deep Water ILI Tool Development and 5 Years Operational Experience

Total Exploration & Production & 3P Services
Total Exploration & Production & 3P Services
The paper describes development of In-Line Inspection (ILI) tools and equipment for deployment in 500+m water depth offshore oil production pipelines. Various design challenges were posed by the operational conditions and the pipeline operator. A joint development project is described in which 3P Services and Total E&P define the necessary tool...