Degassing is a very common operation usually performed during a change of service, maintenance and inspection or decommissioning.
Wherever possible this is done with mechanical pigs but there are many unpiggable pipelines which require this service. Often, pure Monoethylene Glycol is used but this is far from ideal as it does not form a strong barrier to the gas and relies very much on rapid, reliable pumping and even then will use a large volume of MEG.
SANCCUS offer a range of glycol based gels which provide that physical barrier required. Glycol based gels are unique in the pipeline gel family as they have an enormous amount of internal strength provided primarily by hydrogen bonding so unlike other linear gels and all crosslinked gels they will form a full 360° fill of the pipeline even under static conditions. This means that firstly you require far less glycol to swab the water as the gel itself is providing this action but also if there is a pump breakdown and the gel slug stops moving it will remain as a full bore plug and greatly help to prevent gas flow back thereby removing the need to repeat the job.
Being a liquid gel, however viscous, glycol based gels will negotiate any change in pipeline bore while maintain this barrier and if it is operationally viable they can be ejected to the marine environment.
Gel technology is very versatile and can be applied anytime during the lifetime of a field from helping to remove hydrotest fluids when commissioning to the bulk removal of hydrocarbons and solids prior to maintenance or when preparing a pipeline for responsible decommissioning.
Glycostat Gel is a non-crosslinked pipeline gel based on monoethylene glycol. The viscosity profile of Glycostat Gel has been specifically designed to have an extremely high viscosity at low shear rates and a high static gel strength.
Glycotrace Gel is a non-crosslinked pipeline gel based on monoethylene glycol. Strong & slump resistant gel coloured in pink, making it visible by diver or ROV for leak detection in the subsea environment.
Glycotrace Clear is a non-crosslinked pipeline gel based on monoethylene glycol. Strong & slump resistant fluorescent gel which glows green under UV light, making it visible by diver or ROV for leak detection in the subsea environment.
GlycoSol Gel is a non-crosslinked pipeline gel based on a mixture of Monoethylene Glycol and Butyl Glycol. It is lighter than seawater so when a spool is hoisted over the edge of a vessel to just below the water level for the flange caps to be removed it will remain in place in a vertical orientation.
Triton Pig is a unique chemical pig which is 100% soluble in water leaving no reside or other deposit. It was designed for spool filling applications where it is used to push out the gas ahead of the filling medium but unlike a gel pig or foam pig it can be left in the spool where it will dissolve.
M-Gel Pig is a highly flexible gel pig with shape memory used in situations where a mechanical pig cannot be applied. It is capable of extruding through chokes and restrictions up to 50% of its diameter and returning undamaged to its original size and shape once through.
Hyper Gel Pig is a highly flexible gel pig with shape memory which is specifically designed for use in environments of extreme temperature. This means that Hyper Gel Pig can be applied under extreme pipe conditions and can also be stored in very hot or very cold climates without damage.
Atlas Pig is a highly flexible gel pig with shape memory used in situations where a mechanical pig cannot be applied. It is also capable of withstanding pressures up to 600 barg for up to 72 hours. This allows Atlas Pig to be installed during pre-commissioning.
Mono Gel Pig is a pipeline pig made from a mixture of gelled monoethylene glycol and water. Having a melting point of around 30°C it is typically used in colder climates and as with all gel pigs it is used in situations where a mechanical pig cannot be.
Hydro Gel Pig is a pipeline pig made from a mixture of gelatine and water. Having a melting point of around 25°C it is typically used in colder climates and as with all gel pigs it is used in situations where a mechanical pig cannot be.
