Booming business for oil-field-services company Schlumberger is good news for Houston. Flush with profits amid the continued growth in oil and gas exploration, the France-based company could add up to 500 local jobs annually for the next two to three years, Andrew Gould, Schlumberger's chief executive and chairman, said in an interview. The world's largest oil-services provider is also beefing up spending to develop new product lines here and expects to farm out more work to Houston-area companies to keep up with its aggressive growth plans into the next decade, he said. The expansion comes as Schlumberger, with about 5,000...