Schlumberger (SLB -0.89%) has an ace up its sleeve that Halliburton (HAL 0.34%) and Baker Hughes (BHI) wish they could have: a dominant position in what they call the reservoir description business. This service -- which entails things like seismic imaging and subsurface analysis -- is getting more and more valuable by the day. Major oil players like Royal Dutch Shell (RDS.A) and BP (NYSE: BP) rely on this service to make sure they hit oil and gas when they venture out into more risky drilling environments. 

Can Schlumberger hang onto this dominant position over Halliburton and others for long? Tune into the video where Fool.com contributor Tyler Crowe dives into this subject and explains why this segment of the business is a big factor to watch this coming quarter.