Schlumberger (NYSE: SLB ) is one of the largest oilfield service companies in the world, with a market capitalization of roughly $60 billion. Oilfield service companies tend to suffer more during a downturn as capital expenditures dry up much quicker than production, and SchlumbergerThe Value Portfolio specializes in building retirement portfolios and utilizes a fact-based research strategy to identify investments. This includes extensive readings of 10Ks, analyst commentary, market reports, and investor pr ...