Transocean and Occidental Petroleum Parker Drilling are tenants of Four Greenway Plaza which opened in 1975; while the headquarters of Boardwalk Pipeline Partners and Humana Mitsui Oil Exploration is located in Nine Greenway Plaza.
Transocean and Occidental Petroleum Parker Drilling are tenants of Four Greenway Plaza which opened in 1975; while the headquarters of Boardwalk Pipeline Partners and Humana Mitsui Oil Exploration is located in Nine Greenway Plaza.