Offshore

In 2023, an oil and gas operator in the East China Sea needed to upgrade its 28 inch gas export pipeline (GEP), including modifications to the pig launcher and associated pipework on one offshore production platform. The 345-kilometer GEP transports natural gas from the offshore platforms to the onshore processing terminal and is one of the...

As oil and gas operations transition into deeper waters and more technically demanding basins, the integrity of subsea infrastructure has never been more critical. This article examines the role of hydrostatic testing and fluid preservation as a proactive asset-protection strategy. While hydrotesting is a standard verification of mechanical...

Submarine pipelines are externally concrete coated to ensure vertical and lateral stability on seabed without excessive movement. During operation and especially towards late life and beyond, concrete may be lost which must be compensated in the form of stabilization weights. The weight requirements are typically calculated based on concrete...

Subsea pipelines such as in-field flowlines, trunklines, test lines etc. are an integral part of all offshore field developments. This paper covers innovative solutions for carbon footprint reduction from different phases of subsea pipeline life cycle i.e. design, construction and operation. Low carbon field developments are vital and heart of...

Subsea pipelines, such as in-field flowlines, trunklines, etc., are an integral part of all offshore field developments. Pipeline damage can occur either during construction phase or during the life of field. Critical pipeline damage such as leak, rupture, or crack requires repair to be performed on an emergency basis. Repair readiness is being...

Subsea pipelines originating from offshore fields and approaching land are required to be buried in near shore area to provide protection against environmental loading, marine activity, instability and unfavourable soil conditions. This paper presents an innovative approach to optimize near shore burial requirements of subsea pipelines. This...

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...

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...

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...

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...

Subsea pipelines such as flowlines, trunklines etc. are an integral part of all offshore field developments. Sour service conditions as encountered by production pipelines of gas fields require CRA clad pipe due to high risk of localized corrosion initiation and penetration rate in carbon steel. This paper presents an innovative approach to...

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...

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...

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...

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...