Integrated industrial service company A Hak reports that its offshore division, which provides topside, subsea and downhole expertise and equipment, is unique in the South African market.
The company’s range of specialised offshore services centres on its nitrogen pump-ing capabilities, making use of nitrogen pump units, liquid nitrogen tanks and other associated offshore certified equipment. Methods used include nitrogen/helium leak detection and nitrogen purging for decommissioning and recom-missioning operations, subsea pipeline pigging and nitrogen gas lifting for well completions and clean-outs.
In the early 1990s, A Hak opened its base in Johan-nesburg to provide nitrogen-related services to the petrochemicals and refinery industries onshore.
“We saw a niche market in which no other South African company was operating, so the company made the decision to invest in offshore certified equipment that it could use for offshore jobs,” says A Hak GM Mike Hepworth.
Hepworth adds that, until A Hak arrived in the country, service companies from the UK and the US were commis-sioned to do this work, which resulted in elevated costs.
Meanwhile, Hepworth explains that the company is looking at the possibility of expanding its services into the West Coast of Africa.
The company has already completed several operations in Angola, including a major nitrogen services project for oil and gas company Total’s Girassol floating production, storage and offloading (FPSO) vessel, off the coast of Angola.
This project involved the precommissioning leak testing of all the topside process systems on the Rosa system, on board the Girassol FPSO vessel. Using nitrogen and helium, A Hak pressurises each system to its full operating pressure, sometimes as high as 400 bar, after which, using specialised equipment, the whole system is tested for gas leaks. Each leak found is then rectified. This technique guarantees that, when the system is finally commis-sioned, it is leak-tight and safe to operate, says Hep-worth.
He says that work of this nature is extremely specialised, with only a handful of service companies worldwide having the necessary equipment and experience to carry out these kinds of projects.
Although a major oil and gas company requested A Hak to establish a base in Angola a few years ago, the comapny indicated that the timing was not right, which resulted in the development being put on hold.
Hepworth stresses that A Hak South Africa is still a relatively small company, and that establishing a base in Luanda is not without risk. However, the company will reconsider this risk, if approached by the right local partner.
In addition to its topside services, A Hak’s pipeline services division is heavily involved in pipeline testing and inspection.
Offshore operators rely heavily on pipeline systems to transport hydrocarbon products between platforms and to its onshore facilities. The reliability of these pipeline systems is paramount and the ongoing success of the operation lies in the proper maintenance and frequent inspection and testing of these pipeline systems, says Hepworth.
There are a number of techniques available for the inspection of pipelines, of which the most com-mon is a tool called an intelligent pig (IP). A Hak has developed its own IP, which uses ultrasonic technology to check for and measure internal and external corrosion in subsea pipelines.
The tool’s ultrasonic sound waves measure the pipe’s wall thickness as it progresses through the pipeline and will discriminate between internal and external metal loss. This gives the pipeline operator a finite measure of the pipe wall conditions.
When the results are compared with the previous inspection results, the actual rate of corrosion can be calculated, giving the operator an indication of the life expectancy of this subsea asset.
The IP information can also be used to calculate the pipeline’s fitness for purpose. This information is then used by the pipeline user to apply for an operating licence and to satisfy local legislation, which dictates that any pipeline conveying hydrocarbon liquids or gases must be tested and inspected periodically to avoid possible leakages and contamination of the surrounding environment.
Hepworth says that A Hak has performed intelligent pigging for almost every major oil company in the world.
Other projects include providing topside services for State-owned petroleum company PetroSA’s FA Platform off Mossel Bay, FPSO operator Bluewater’s ship, Glas Dowr, and oil and gas corporation Exxon Mobil’s Kizomba A Platform.
In addition to the nitrogen pumping and intelligent pigging, A Hak offers indus-trial services, such as reactor cooling, furnace decoking and system drying, which includes pneumatic and hydrostatic testing and nitrogen/helium leak detection. Its pipeline services range from pigging, cleaning and drying to the pre- and decom-missioning of pipelines, while its inspection services include nonpiggable pipelines. A Hak Industrial Services is a subsidiary of the Dutch A Hak, which has its head office in Tricht, in the Nether-lands.