There are requirements for the well to be capped below the mud line, then the area dragged to remove any debris. However, there is a 2 year time frame for this to be performed, so if you hit the old wellsites fairly soon after removal, there's a chance they haven't done it yet. In addition, it has been my experience that the rigs located in 100 ft+ of water are not cleaned as efficiently as the shallow water rigs. They are definitely worth hitting.
Then there's the wellheads and cutoffs - I'm not sure what dictates which rig is selected for this. Our new Realtime-Navigator website (
www.reatime-navigator.com) features the latest rig locations updated once a month.
All the best,
Tom Hilton