Schlumberger Campus, Texas

Schlumberger is the leading oil field services company in the world, with around 126,000 employees, and over $45 billion in revenue in 2013. The company was founded in France in 1926 by the Schlumberger brothers, who invented wireline logging, a technique for obtaining and interpreting oil well information from inside the ground. Today, Schlumberger offers a wide range of products and services, including sophisticated wireline logging; drilling services; well services (e.g. cementing, stimulations, and sand control); well completion and testing services; integrated project management services; and software, information management, and IT infrastructure services. The company's WesternGeco division is the largest seismic company in the world, finding and mapping oil reserves around the globe. Though it is incorporated in Curacao (a Caribbean island in the Dutch East Indies), Schlumberger has been largely based in Houston since 1935.