ENEGI Oil's plan to use unmanned buoys to offer a low-cost way of developing marginal North Sea fields is in line for a significant boost from Wood Group.

The oil services giant has agreed to form a joint venture with Enegi to provide buoys that the partners believe could transform the economics of many so-called stranded and marginal fields.

Aberdeen-based Wood Group will provide engineering services at its own expense to get the buoys developed by Enegi and a floating tower ready for use on a field.

It has also agreed to provide working capital and up to £5 million engineering services, with payment for them deferred, towards the venture's work on selected small fields Enegi hopes to bring into production using the buoys.

The arrangements are defined in a Memorandum of Understanding between the firms.

Led by former Scottish squash international Alan Minty, Manchester-based Enegi will try to complete definitive agreements with Wood Group while work continues on the buoy programme.

Coming three years after the companies signed a strategic partnership to commercialise the buoy technology, the memorandum looks like a notable development.

Dave Stewart, managing director of the Wood Group PSN business, which has a big North Sea presence, said:

"This is an exciting new development for Wood Group PSN, aimed at maximising recovery of marginal field reserves in the United Kingdom Continental Shelf, reducing running costs for operators and making previously sub-economic fields financially viable."

The buoys under development would sell for £60m to £80m. They are designed to sit just below the surface of the water, with an access tower protruding, and be attached to wells on the seabed. They include oil and gas separation and storage facilities.

Backers say they could be used to develop fields that are too small, or too distant from infrastructure like pipelines, to be developed using conventional technology.

Enegi Oil and Antrim Energy plan to use a floating tower on the Fyne field.