Oil-field services companies such as Halliburton and Schlumberger say they have sharpley reduced their prices… The worst of the oil bust may be over, but the energy industry’s infighting has just begun. Paal Kibsgaard, chief executive of Schlumberger Ltd. SLB -3.04 % , the world’s largest oil-field services company and a bellwether for the sector, told investors Friday that from now on, his company will only focus on work that is profitable. It was a shot across the bow of U.S. and international energy companies, which need Schlumberger and companies like it to help drill new wells and do hydraulic fracturing, but which have been paying sharply reduced rates for such services amid the plunge in oil prices. In the two years since crude prices plunged from over $100 a barrel down to around $26 earlier this year, Schlumberger and chief rival Halliburton Co. HAL -0.66 % drastically reduced […]