< PrevNext > 68. Schlumberger Houston Share 2018 U.S.-Booked Air Volume: $60 millionBTN estimates Schlumberger's U.S.-booked air volume fell $3 million from 2017 to 2018. The oilfield services technology provider employs approximately 100,000 people in over 85 countries. Its revenue grew 8 percent to $33 billion in 2018. Schlumberger has expanded its use of remote operations centers to service clients and support its products, reducing the company's travel.