Bordered by the largely untapped Caspian Sea, Azerbaijan is fast becoming a major oil exporter whose developing resources are increasing rather than declining alongside other non-OPEC countries' output. As of January 2009, the Central Asian country contained estimated proven oil and natural gas reserves of roughly 7 billion barrels and 30 Tcf, respectively. Azerbaijan's massive Shah Deniz field is one of the world's largest natural gas discoveries of the past two decades and is operated by BP, with state-run SOCAR retaining a 10% stake in the field.
Drilling fluids, also referred to as drilling mud, are added to the wellbore to facilitate the drilling process by suspending cuttings, controlling pressure, stabilizing exposed rock, providing buoyancy, and cooling the drill bit. Mud engineers ensure that the drilling mud that is used is made to the required specifications based on the expected geology. Drilling fluids can be water, oil, or synthetic-based, and mud engineers must take rock formation composition, as well as environmental impact, into account when making decisions about what drilling fluids might be best for any given well.