GeoResources: Strong Reserve Report

[dan_s]

Houston, Texas, March 6, 2012 – GeoResources, Inc. (NASDAQ: GEOI), today announced its year
end 2011 proved reserves, and its fourth quarter and full year 2011 production results. The company also
provided an operational update and issued revised capital expenditure and production guidance for 2012.
SEC Proved Reserve Highlights(1)
• Proved reserves totaled 29.2 Mmboe at January 1, 2012, a 22% growth rate over January 1, 2011.
• Proved oil reserves grew 37% from prior year levels and accounted for 67% of total proved reserves
at January 1, 2012, up from 60% in the prior year.
• The proved PV-10 totaled $615 million at January 1, 2012, a 63% growth rate over prior year.
• The Company’s reserve replacement ratio from acquisitions and drilling was 340%(2) for the year
ended December 31, 2011.

Year End and Fourth Quarter 2011 Production Highlights
• Combined oil and gas production for 2011 averaged 5,270 boe/d (64% oil), a 4% increase over 2010.
• Oil production averaged 3,349 bbl/d for the year, a 15% increase over 2010.
• Combined oil and gas production averaged 6,116 boe/d in the fourth quarter of 2011 (67% oil), a
20% increase over the fourth quarter 2010 and a 10% increase over the third quarter 2011.
• Oil production averaged 4,084 bbl/d in the quarter, a 34% increase over the fourth quarter 2010 and a
13% increase over the third quarter 2011.