Shell and Texaco are 2 different companies. Shell is part of Royal Dutch (technically a Netherlands company, but with all substantial headquarter operations in the UK) while Texaco is simply a brand under Chevron.
You don’t understand what you’re talking about. They are legally enforceable contracts. If you had a contract with someone to pay you money if something happened and you were paying them ahead of time for that benefit, you’d be pissed to have it invalidated.
In many cases, there is oil on these 68million acres, but it’s too costly to extract at this time. If it wasn’t, the integrated oil companies would be drilling on it. But because deepwater drilling has had many technological advances recently with regard to better and cheaper equipment to get to lower depths, the companies are hanging on to and renewing the leases in the hopes that it becomes more economical at some point in the future. The seismic and other analysis of these continental shelf areas is more promising. And that is why they are asking to drill there.