Jan 23 (Reuters) - U.S. natural gas output in the Marcellus and Utica shale in Pennsylvania, Ohio and West Virginia dropped by 7 percent on Wednesday, following an explosion reut.rs/2FHIMVn on Enbridge Inc's Texas Eastern (TETCO) pipeline on Monday.
The blast, which injured two people who lived nearby and damaged three homes, occurred on TETCO's 30-inch (76.2 cm) line about two miles south of Summerfield in Noble County in southeast Ohio at around 10:40 a.m. EST (1540 GMT), the Calgary-based company said in a statement.
Before the incident, drillers were producing about 30 billion cubic feet per day (bcfd) of gas in the Marcellus and Utica region. That dropped to just 28 bcfd on Wednesday, according to Refinitiv, a financial data provider.
One billion cubic feet is enough gas for about 5 million U.S. homes for a day.
At the time of the blast, gas was flowing through TETCO from the Marcellus and Utica shale fields south toward the Gulf of Mexico, according to gas traders.
The amount of gas moving through TETCO south of the damaged pipe in Athens and Scioto Counties in southern Ohio dropped from around 1.2 bcfd on Monday to less than 0.1 bcfd on Wednesday, according to Refinitiv data.
In Bath, Monroe and Boyle Counties in Kentucky, flows also fell from over 1.0 bcfd on Monday to about 0.1 bcfd Wednesday.
In Pennsylvania, meanwhile, flows in Greene County in the southwest corner of the state reversed direction from 0.6 bcfd moving West on Monday to 0.4 bcfd heading east on Wednesday. Greene County is one of Pennsylvania's biggest gas producing counties.
Officials at Enbridge could not say when the damaged section of pipe would return to service. The Calgary-based company said it was working with the Public Utilities Commission of Ohio and the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA) to identify the cause, monitor repairs and evaluate environmental impacts.
Enbridge said the damaged section of pipe was built in 1952-53 and an inspection of the line was performed in 2012 with no remediation needed.
The 9,029-mile (14,531-km) TETCO pipeline was designed to carry gas from the U.S. Gulf Coast and Texas to high-demand markets in the mid-Atlantic and Northeast. It became bi-directional over the past five years, enabling it to also carry gas from the Marcellus and Utica shale, where production is growing rapidly, to markets in the U.S. Midwest and Gulf Coast.
Reporting by Scott DiSavino; Editing by Bernadette Baum