Big Oil prepared to sue to stop offshore wind farms

They claim a few turbines would be disruptive to their operations:

The warning over legal action came from trade body Oil and Gas UK. The government is currently consulting on national policy statements, which set out how the UK's ambitious renewable energy targets will be met, with offshore wind turbines a key factor. In its submission, Oil and Gas UK said the policy statements did not take account of the way offshore wind farms could impede mobile drilling rigs, disrupt helicopter flights and get in the way of pipelines and underwater equipment.

From the Guardian. What do you think their real reason is?