The company will work for Apache for up to five years using remote operated vessels and specialist divers to help maintain the sprawling portfolio built by the US giant.
While the value of the Apache contract was not disclosed, Harkand said the award was an important success.
Harkand Europe managing director, David Kerr, said: "This contract is an important step in strengthening our close working relationship and growing our North Sea business with Apache."
Harkand could hope to win more North Sea business from Apache if the American firm continues to expand in the area.
Apache acquired the giant Forties field 110 miles east of Aberdeen in 2003. It underlined its enthusiasm for the North Sea in 2012 when it bought a basket of assets from ExxonMobil for $1.4bn. The assets include the Beryl and Buckland fields east of Shetland .
The award to Harkand provides further evidence of how strong activity levels among oil and gas exploration and production companies in the North Sea are providing a boon for the services companies that help them develop new fields and get the most out of existing assets.
Harkand noted recently that the start of the year saw a busy tendering period which spurred demand for ROVs in the North Sea.
Firms specialising in ROVs have been hard at work helping oil and gas firms with work like laying new pipelines.
Harkand has also won North Sea contracts from CNR and Nexen in recent months.
Mr Kerr said the company expects the North Sea market to remain strong for years. "R and M (repairs and maintenance) is going to go on and on and on," he said.
He noted that firms are likely to continue investing heavily in extending the life of existing assets, partly because it will only be economic to develop some small discoveries if they can be tied back to infrastructure that is in place.
The business wins will be welcomed by Oaktree Capital, which formed Harkand in 2013 to capitalise on expected growth in energy markets worldwide.
The US private equity firm combined Aberdeen-based Integrated Subsea Services and Andrews Survey with the Middle East-based Iremis diving vessel business to form Harkand.
A number of overseas-based private equity firms have invested in Scots oil services businesses in recent years.
The sector is still quite fragmented providing opportunities for financial buyers to follow consolidation strategies. With expertise developed in the North Sea in strong demand abroad, private equity firms have supported overseas expansion moves made by oil services companies.
Harkand bought Houston-based Veolia Marine Services last year.
It said the award by Apache includes the provision of vessels, ROV and diving services for a three-year period, plus two one-year options.
Harkand has 32 ROVs including 21 in the North Sea. The group has around 750 people working for it in and out of Aberdeen, including contractors.