Gold Silver Reports (GSR) – Growth in Shale, Frackers Preach Patience on Payoff From $70 Oil — While first-quarter earnings were less than exciting, Schlumberger Ltd., the largest service provider, said it plans to profitably add about 1 million horsepower worth of rock-crushing pumps this year into North American shale. Halliburton Co., the fracking king, said it sees a return to the 20 percent profit margins last seen before the downturn.