Chesapeake Energy battles Marcellus Shale blowout
Fracing fluids flow into Susquehanna tributary
CHESAPEAKE Energy is still battling to bring a wild well in the Pennsylvania sector of the Marcellus Shale under control after the bore blew out during hydraulic fracturing (fracing) work earlier this week. Thousands of gallons of flowback fluids escaped into a tributary of the Susquehanna River.
The Chesapeake drilling crew lost control of the shale-gas well just before midnight on Tuesday. They were able to contain much of the overflow at the site, but liquid, believed to be completion fluids, spilled into a nearby stream. Seven families in Leroy Township, in Bradford County, were evacuated as a precaution. In an emailed statement, Chesapeake said the blowout was caused by equipment failure. No one was hurt in the incident and there are no reports of gas being released into the atmosphere.
Katy Gresh, a spokeswoman for the Pennsylvania Department of Environmental Protection, said Chesapeake had contained the spill at the drill site, but added that the well is not yet under control. In its statement, Chesapeake said Halliburton well control unit Boots & Coots International Well Control is on stand-by and may be called in if necessary.
Gresh added that state environmental regulators are set to test samples of water from the creek and will be monitoring privately owned water wells in the area for contamination.
The timing of the incident could not have been worse for the industry. The blowout occurred on the eve of the first anniversary of the Deepwater Horizon disaster in the Gulf of Mexico.
The Marcellus incident will add fuel to an already heated debate about fracing and appears to add weight to critics’ claims that chemicals used in the process could seep into groundwater and potentially contaminate drinking-water supplies.
Those chemicals comprise less than 0.5% of the contents of the fluids that are forced into virtually impermeable shale formations to crack them open, releasing trapped oil and gas that would otherwise be uneconomic to produce. Although drilling companies have been reluctant to reveal the ingredients of their fracing fluids for competitive reasons, critics question the effect of these chemicals on public health.
Industry representatives say well-construction practices – including lining the wellbore with layers of steel casing and cement – keep fluids from escaping and provide effective protection against groundwater contamination.
But incidents have still occurred. In June last year, a blowout at a well in Clearfield, Pennsylvania, saw more than 35,000 gallons of fracing fluids spew from the wellbore.
Chesapeake has also had its share of problems in the Marcellus Shale, which spans most of Pennsylvania, all of West Virginia and parts of Ohio, Kentucky and Tennessee. Last September, one of its wells in the part of the play that extends into West Virginia caught fire, resulting in a gas release; and in February, three workers were injured in a fire and explosion at a well in southwestern Pennsylvania.
The US’ second-largest gas producer, Oklahoma-based Chesapeake pioneered the development of the country’s shale plays and now ranks as the largest leasehold owner in the Marcellus, the world’s second-largest gasfield, with reserves estimated at around 490 trillion cubic feet (cf). Chesapeake holds about 3m gross acres in the play, and its 450 Marcellus Shale wells produced more than 100bn cf of gas equivalent last year.