Rex Energy Announces 2007 Year-End Proved Reserves Rose 10% to 15.9 Million Barrels...

Rex Energy Announces 2007 Year-End Proved Reserves Rose 10% to 15.9 Million Barrels of Oil Equivalent

STATE COLLEGE, Pa.--(Business Wire)--Rex Energy Corporation (NASDAQ:REXX) announced today that its
estimated total proved reserves of natural gas and crude oil as of
December 31, 2007 increased 10% to 15.9 Mmboe (or 95 Bcfe), as
compared with 14.5 Mmboe (or 87 Bcfe) at year-end 2006. The 2007
reserves are comprised of 18.5 Bcf of natural gas and 12.8 million
barrels of crude oil. Of the 15.9 Mmboe of total proved reserves, 78%
are categorized as proved developed, while 22% are proved undeveloped.

The present value of future cash flows before income taxes as of
December 31, 2007, discounted at 10% (SEC PV10), totaled $392.1
million, utilizing year-end pricing of $6.79 per mcf for natural gas
and $92.50 per barrel of crude oil. This represents a 96% increase
over the $200.3 million of present value reported at year-end 2006.
These estimates are based on an independent engineering study of Rex
Energy's oil and gas properties prepared by Netherland, Sewell &
Associates, Inc.

Benjamin Hulburt, CEO, stated, "We are very pleased with this
increase in our proven reserves. During 2008, we plan to continue to
grow our proven reserves as we develop our extensive asset base,
including our enhanced oil recovery project in the Illinois Basin and
our Marcellus Shale position in the Appalachian Basin."

About Rex Energy

Rex Energy is an independent oil and gas company operating in the
Illinois Basin, the Appalachian Basin and the southwestern region of
the United States. The Company pursues a balanced growth strategy of
exploiting its sizable inventory of lower-risk developmental drilling
locations, pursuing its higher-potential exploration drilling and
enhanced oil recovery projects, and actively seeking to acquire
complementary oil and natural gas properties.

For more information, contact: Joseph DeSimone, Director of
Investor Relations, at (814) 278-7267 or jdesimone@rexenergycorp.com

FORWARD-LOOKING STATEMENTS

Except for historical information, statements made in this
release, including those relating to significant potential, future
earnings, cash flow, capital expenditures, production growth and
planned number of wells, are forward-looking statements within the
meaning of Section 27A of the Securities Act of 1933 and Section 21E
of the Securities Exchange Act of 1934. These statements are based on
assumptions and estimates that management believes are reasonable
based on currently available information; however, management's
assumptions and the company's future performance are subject to a wide
range of business risks and uncertainties, and there is no assurance
that these goals and projections can or will be met. Any number of
factors could cause actual results to differ materially from those in
the forward-looking statements, including, but not limited to, the
volatility of oil and gas prices, the costs and results of drilling
and operations, the timing of production, mechanical and other
inherent risks associated with oil and gas production, weather, the
availability of drilling equipment, changes in interest rates,
litigation, uncertainties about reserve estimates and environmental
risks. The company undertakes no obligation to publicly update or
revise any forward-looking statements. Further information on risks
and uncertainties is available in the company's filings with the
Securities and Exchange Commission, which are incorporated by
reference.

Rex Energy Corporation
Joseph DeSimone, Director of Investor Relations
814-278-7267
jdesimone@rexenergycorp.com

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