I've had extensive business relationships with research scientists at both XOM and SLB.  In my experience big oil makes a point of only employing top talent in engineering and science.  However my colleagues were often frustrated by their management's conservative approach to adopting new technology and emphasis on practical results that impacted the bottom line in the near-term.  They were constantly in fear of the budget consequences of the next dip in the price of oil as R&D is one of the first areas that big oil cuts when the profits dry up.  I agree that this culture has tended to stifle real innovation, instead making big oil R&D departments procurers of technology that others have paid to develop to a fairly high technical readiness level.  I've seen big oil swallow up 100 person companies and fairly hefty patent portfolios without a one line blurb on their web site; sometimes the technology ends up down a well or in an exploration ship; sometimes it doesn't produce $ soon enough and gets flushed never to be seen again.

Most of the real innovation occurs in universities, gov labs, or much smaller dynamic start-ups, which is why government R&D spending, progressive small business R&D tax treatment and especially availability of private venture capital are far more important to solving our energy supply problems than big oil R&D expenditures.