The oil industry is currently undergoing a massive consolidation wave. Sector leader ExxonMobil kicked things off by acquiring Pioneer Natural Resources in a more than $60 billion deal. Chevron followed it by agreeing to buy Hess for $60 billion. Several other oil companies also struck deals to acquire smaller rivals, including Occidental Petroleum (OXY 1.88%), which bought CrownRock in a $12 billion deal. One of the critical differences between Occidental's deal and the acquisitions of its larger peers is ...