This capability forms part of a comprehensive pipeline support service comprising pipeline intervention (hot tapping, line stopping and pipe freezing), plus hydrotesting, pigging and other services, including emergency support, now offered to pipeline operators by Furmanite Australia. The company has considerably extended its service and capability in this field, following the acquisition of Pipeline Support Pty Ltd by Furmanite Australia in June this year, coupled with Furmanite’s acquisition last year of Flowserve GSG including Ipsco.
Furmanite Australia and New Zealand National Sales Manager Michael Pearson says the latest acquisition amalgamates significant pipeline intervention experience, expertise and service support capability gained from Pipeline Support, with Furmanite Ipsco’s considerable existing technology and expertise. The result is a total pipeline support and maintenance package with local service and expertise, coupled with the substantial resources and backing of a global organisation.
“Given the high cost of downtime, even when planned, pipeline intervention services are particularly attractive in facilitating repairs or modifications to pipelines, on and offshore, without shutdown or disruption to service,” Mr Pearson points out.
“Whether it is for planned maintenance, emergency repairs or system expansions, this represents high value.
“Pipeline intervention services provide temporary isolations; typically to allow a branch connection tie-in, a malfunctioning valve, pump or other equipment to be changed out, instrumentation (such as flow meters, pig indicators or internal visual surveillance equipment) to be installed, or a line re-routed, while the system remains pressurised,” he explains.
Outlining how the technologies work, Furmanite pipeline intervention manager Jim Sayers summarises the hot tapping process, for which equipment is selected (or adapted if necessary) to suit the application, depending on the product type, line pressure, temperature, line and branch nominal size, wall thickness and operating conditions.
“The process starts with a welded or mechanical fitting installed on the line with a temporary or permanent valve, depending on the application, and a drilling machine is used to break through the wall of the pressurised line using a pilot drill,” he explains.
“The pipeline content fills the void beneath the drill, and air is expelled through the purge valve, which is then closed to retain the pressure. The cutting process continues to complete the cut, and cutter and coupon (the disc that is cut out) are removed.”
Line stopping also begins with a hot tap and temporary valve, Mr Sayers continues, through which a mechanical plugging head is inserted into the line, rotated and locked into position. “The sealing element with which the plugging head is fitted is activated in the line under pressure,” he explains. “This temporarily stops pipeline flow, or redirects it through a bypass, providing a safe and cost-effective isolation while the system remains live.”
He also points to pipe freezing which solidifies the content of a liquid-filled pipe (such as oils, water, or chemicals) to form a pressure-resistant plug, and achieve a temporary isolation.
Examples of these pipeline intervention services in application are widespread, from the block valve station replacements along a main crude export line, and installation of a gas compression station on a high pressure gas line, to hot taps to tie-in branch connections to 20 inch and 36 inch carbon steel natural gas lines, and a double stop and bypass to relocate a water main without interrupting service.
Increasingly, subsea application of hot tapping and line stopping services is required – a demand with additional challenges. Mr Pearson points out that Furmanite Ipsco has the capability to perform subsea hot taps and line stops at depths to 300 metres, work to date having included single and double line stops, citing what is believed to be the world’s largest subsea hot tap on a
36 inch main sour gas line at 150 metres depth. “Growing interest in this field makes this an exciting area for further development,” he says.
“A typical example lies in the recent contract to undertake a subsea hot tap into a 12 inch oil and wet gas line at 24 metres depth to tie in an eight inch branch for Apache Energy, off the Varanus Island oil and gas processing facility on the North West Shelf, as part of a field extension project,” he adds.
Where necessary, Furmanite can also engineer bespoke solutions to meet specific requirements, as in one case where the company designed six high pressure self-sealing hot tap tee clamps for installation over a length of 115 metres on a main crude oil line at 120 metres depth, to allow a solvent to be injected to dissolve natural deposits that had built up in the line.
As Mr Pearson emphasises, the ability to apply these technologies to undertake repairs and modifications without disrupting normal operation has a high value to operators. “We also now provide a number of operators with an emergency support service on a 24/7 call-out basis, delivering pipeline intervention services as required in case of emergency,” he adds.
“With the experience, equipment, and engineering expertise we now offer, we can provide even greater capabilities from which pipeline operators can benefit.”