If you wanted to defend an O&G field, wouldn't you need to consider a similar extent? per wellhead, yes. but the go to a concentrator for onshore feed don't they? or some kind of attached floating rig, which itself is a SPF.

I thought fields had 100s of square km of extent too. The exclusion zone after nordstream is now pretty big, albiet "temporary" according to the web its 5 to 7 nm so 9 to 13 km so close to 100 km^2

All of which are continually manned. Not so w/ offshore wind