Stone Energy Announces 2012 Reserve Growth of 28%, Production Replacement of 288%

Stone Energy Corporation

today announced its estimated year-end 2012 proved reserves were 129 Mmboe (million barrel equivalents) or 773 Bcfe (billion cubic feet of natural gas equivalent), as compared with 100 Mmboe or 602 Bcfe at year-end 2011, representing a 28% increase in its estimated proved reserves.  From all sources, Stone replaced approximately 288% of production in 2012. The estimated proved reserves were 35% oil, 14% natural gas liquids (NGLs) and 51% gas on an equivalent basis. The changes from 2011 year-end estimated proved reserves to 2012 year-end estimated proved reserves included production of approximately 15 Mmboe or 91 Bcfe, drilling additions/extensions of 30 Mmboe or 181 Bcfe, net upward revisions of 7 Mmboe or 44 Bcfe and net acquisitions of 6 Mmboe or 37 Bcfe. The present value of the estimated future net cash flows from estimated proved reserves before income taxes, using a 10% discount rate (PV10), was approximately $2.0 billion using 12 month average prices after differentials of $101.20 per barrel of oil, $38.23 per barrel of NGLs and $2.68 per Mmbtu of gas.  The estimated year-end 2012 proved reserves included proved developed (PD) reserves of 73 Mmboe or 437 Bcfe (split 40% oil, 12% NGLs, 48% gas) and proved undeveloped (PUD) reserves of 56 Mmboe or 337 Bcfe (split 28% oil, 17% NGLs, 55% gas).  In addition, there were 59 Mmboe or 356 Bcfe of estimated probable reserves and 167 Mmboe or 1.0 Tcfe of estimated possible reserves at year-end 2012. All of Stone's 2012 year-end estimated proved, probable and possible reserves were independently engineered by Netherland Sewell & Associates.