MarkWest Energy Partners LP said Monday that most of its Houston Processing and Fractionation facility in southwest Pennsylvania is back online after a lightning strike late last Wednesday forced the company to shut down operations there so it could assess the damage (see Shale Daily, May 29).

In an update on Monday, MarkWest said the assessment revealed that the incident was isolated to a heat exchanger at one of three processing plants at the complex, located in Chartiers Township, about 30 miles southwest of Pittsburgh in Washington County. The company said two of the plants and of all of the facility’s fractionation units were once again operating. The third processing plant will remain shut down so that repairs can be made to the heat exchanger.

In addition to a three-hour evacuation of nearby homes after the lightning strike last Wednesday, MarkWest was forced to reroute natural gas to its Majorsville complex in Marshall County, WV, 50 miles west of the Houston facility, which is connected with a large, high pressure rich-gas header system. The company said Monday that some gas will continue heading to West Virginia until repairs at the Houston facility are completed.

In a press release issued last week, Range Resources Corp., which supplies the most gas volumes to the Houston facility, said it was forced to shut-in some wells when the plant was shut down. Range added, however, that its production was only nominally impacted in the area. The Houston facility has a processing capacity of 355 MMcf/d and another 98,000 b/d of ethane and heavier fractionation capacity.

In unrelated news, MarkWest said a long-awaited expansion to its Keystone facilities in western Pennsylvania is complete, with the commencement of its 120 MMcf/d cryogenic processing facility, Bluestone II.

In 2012, MarkWest acquired those properties, in Evans City, PA, from Keystone Midstream Services LLC for $512 million (see Shale Daily, May 9, 2012). At the time, MarkWest said it would expand upon 90 MMcf/d of processing capacity at two plants there in order to meet demand for forecasted production growth.

Along with its nearby Sarsen facilities, the company has increased processing capacity for operators in the area to 210 MMcf/d. It also said Monday that 20,000 b/d of ethane and heavier fractionation capacity was online at the Keystone facilities.

Bluestone I and II primarily support the rich gas production of Rex Energy Corp., which has steadily been increasing production in its Butler Operated area of western Pennsylvania (see Shale Daily, March 28). The company said in December that it had reached capacity at the 90 MMcf/d Bluestone I and Sarsen plants, forcing it to shut-in wells and await MarkWest’s completion (see Shale Daily, Dec. 6, 2013).

Rex said Monday that it had started flowing to Bluestone II in mid-May as it expected. It added that it has already placed five of the 11 wells awaiting the expansion into sales, with plans to turn five others into sales this week and the remaining well into sales by the end of this quarter.

The Bluestone expansion will also help Rex to start its first ethane sales of 2,000 b/d this month, with an incremental 3,000 b/d to start in July. Rex added that it will soon update this year’s guidance of 143-149 MMcfe/d.