Oil majors are not only increasingly dominant in upstream output from Texas’ key Permian basin, they are also pioneering an integrated development model with key midstream and downstream assets. Gulf NOCs are playing a supporting role.

Exxon is ramping up its Permian ambitions. Together with deepwater Guyana and Brazil, the Permian forms the centerpiece of the major’s investment plans. Exxon only went big on the Permian with the $6.6bn purchase of key acreage in early 2017. But...