Exxon has 19,400 acres in the Marcellus shale

HOUSTON, March 30 (Reuters) - Exxon Mobil Corp XOM, the
world's largest publicly traded company, has leases on 19,400
acres in the Marcellus Shale, a formation that is said to hold
vast amounts of natural gas.
In September, Exxon bid $85.2 million for 18 blocks in the
Marcellus, a large shale formation that runs through parts of
New York, Pennsylvania, Ohio and West Virginia.
Exxon, based in Irving, Texas, was the high bidder on six
Marcellus blocks, paying a total of $22.4 million for acreage
in Tioga and Lycoming counties in Pennsylvania, company
spokesman Patrick McGinn, said.
Until recent technological advances, the natural gas
trapped in shale was considered too expensive or difficult to
retrieve.
But now, processes like hydraulic fracturing are used. In a
"frac job," propellants like sand grains and liquids are pumped
into a well under pressure high enough to crack the shale and
allow the release of oil and gas.
McGinn would not comment on Exxon's plans in the
Marcellus.
European oil majors StatoilHydro STL.OL and BP Plc BP.L
have struck billion-dollar shale asset deals in North America.
Elsewhere in North America, Exxon Mobil has acquired
152,000 net acres since 2007 in the Horn River Basin in
northeast British Columbia. Exploration drilling activity to
evaluate the Horn River shale gas play began in late 2008, the
company said in its annual report.