Still, it has plenty of competition from Halliburton ( HAL -4.13% ), which has made the most rapid progress among its peers in expanding beyond its traditional stomping grounds in North America. Like Schlumberger, Halliburton is also aggressively targeting key regions in the Middle East and Asia, which means investors can expect some heated competition between the two -- and even Baker Hughes -- as they fight to gain dominant market share in these high-growth regions.