Rex Energy Proved Reserves Increase 10% for 2007

Rex Energy reported that 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 the company's oil and gas properties prepared by Netherland, Sewell & Associates, Inc.