Schlumberger (SLB) is one of the stocks most watched by Zacks.com visitors lately. So, it might be a good idea to review some of the factors that might affect the near-term performance of the stock.Shares of this world's largest oilfield services company have returned -4.5% over the past month versus the Zacks S&P 500 composite's +2.1% change. The Zacks Oil and Gas - Field Services industry, to which Schlumberger belongs, has lost 5.6% over this period. Now the key question is: Where could the stock be head ...