Drilling failure causes oil leak

An equipment failure at a natural gas well in Ohio, US resulted in 1,600 gallons of lubricating oil to leak into a river tributary. The PDC Energy Inc site experienced a build-up of pressure on Sunday May 4th, according to the Associated Press, but workers weren't able to contain it due to an equipment malfunction, causing the leak.

The failure of the drilling equipment resulted in the oil-based lubricating fluid to leak. The oil was able to reach a creek that is a tributary of the Muskingum River, possibly resulting in water pollution. Crews were attempting to stop the oil spreading any further by making use of containment dams along the creek.

Around ten gallons per minute of the lubricating oil was able to leak following the failure. The spill resulted in residents from nearby houses being evacuated as a precaution in case the leak led to an explosion, due to escaping natural gas. 

The US Environmental Protection Agency said that an unexpected pocket of natural gas was the cause of the pressure build-up, resulting in the well head failure that caused the leak. As well as the lubricating oil, the incident caused wet gas to leak from the well, although it is not known how much escaped.

The spill was contained by Wednesday May 7th, according to officials. While most of the oil appears to have been collected, it could still be damaging to marine life in the area. However, the extent of the damage is not yet known.

The oil-based fluid is used to lubricate the drill bits that create the wells for natural gas drilling. The fluid used during the drilling of this well was made up of a blend that was 75 per cent synthetic oil. Between 75 and 100 workers were onsite in the days following the incident to clean up the leak.