The largest oilfield services company in the world by revenue, market capitalization, and global operational footprint is Schlumberger (operating internationally as SLB). Headquartered across multiple international hubs, SLB provides comprehensive upstream technology, reservoir characterization, drilling, production, and processing services to major petroleum exploration and production corporations worldwide. Other massive global contenders include Halliburton and Baker Hughes, which similarly dominate large-scale international hydrocarbon extraction support.