Rex Energy Announces 61% Net Increase In Proved Reserves And Provides Operational Update

• Year-end 2010 proved reserves increased to 201.7 BCFE
• Total reserve replacement at 1,560%
• 2011 production expected to increase 71%-95% from 2010
• Capital budget set at $148.8 million with 74% allocated to oil and liquids rich plays

STATE COLLEGE, Pa., Jan. 26, 2011 (GLOBE NEWSWIRE) -- Rex Energy Corporation (Nasdaq:REXX) today announced that its total proved reserves as of December 31, 2010 increased 95% from 2009 year-end estimates to 201.7 Bcfe prior to adjustments for production, asset sales and revisions. Total proved reserves for crude oil and natural gas liquids and natural gas as of December 31, 2010 consisted of 12.3 Mbbls and 127.6 Bcf, respectively. The company replaced 1,560% of its estimated 2010 production with a reserve to production (R/P) ratio of 27.6 years.

The following table summarizes the company's proved reserves as of December 31, 2010:

	Natural Gas (Mmcf)	Oil and NGLs (Mbbl)	Total (Mmcfe)
Balance – December 31, 2009	56,163	11,510	125,223
Extensions and discoveries	93,230	3,462	114,000	(1)
Sale of minerals in place	(12,252)	(370)	(14,470)	(2)
Estimated production	(3,008)	(717)	(7,310)	(3)
Revisions to previous estimates	(6,512)	(1,542)	(15,764)	(4)
Balance – December 31, 2010	127,622	12,343	201,679	(5)
Proved developed reserves as of December 31, 2010	32,477	8,799	85,272
(1) Butler County Marcellus Shale reserves up 248% over 2009
(2) Sales to Sumitomo as part of joint venture transaction
(3) Unaudited 2010 production figures
(4) Includes reclassification of 3.7 Bcfe and 13.5 Bcfe from Appalachian Basin (non-Marcellus) and Illinois Basin, respectively, to the probable category
(5) Total proved reserves increased 61% adjusting for production, assets sales and revisions

Due to the transition from conventional drilling to horizontal drilling in its Appalachian Basin operations and focus on higher impact projects, the company does not intend to drill certain conventional locations within the next five years. As a result, the company has excluded approximately 17.2 Bcfe of conventional Appalachian Basin and Illinois Basin proved undeveloped reserves from its year-end 2010 proved reserves. This reclassification complies with the Securities and Exchange Commission rule for "Modernization of Oil and Gas Reporting" which requires proved undeveloped locations to be drilled within five years of the first booking date of the well.