Clayton Williams Energy Replaces 732% of its 2004 Production

Clayton Williams Energy announced that the Company's total proved oil and gas reserves as of December 31, 2004 were 299 Bcfe, consisting of 26.8 million barrels of oil and NGL, and 138.3 Bcf of natural gas, as estimated by independent petroleum engineers. By comparison, the Company reported proved reserves of 124.9 Bcfe as of December 31, 2003, consisting of 10.3 million barrels of oil and NGL and 62.9 Bcf of natural gas. The pre-tax present value of estimated future net revenues from these reserves, discounted at 10% and computed in accordance with SEC guidelines, totaled $705.3 million at December 31, 2004, as compared to $335.1 million at December 31, 2003. The estimates were based on weighted average oil and NGL prices of $41.48 per Bbl in 2004, as compared to $30.45 in 2003, and gas prices of $5.59 per Mcf in 2004, as compared to $5.61 per Mcf in 2003.

During 2004, the Company replaced 732% of the 32 Bcfe produced in 2004. Of that, purchases of proved reserves added 170.8 Bcfe (534%), extensions and discoveries added 46.8 Bcfe (146%), and net revisions added another 16.6 Bcfe (52%). The following table summarizes these changes in proved reserves during 2004 on a Bcfe basis.

Total proved reserves, 12/31/03        124.9
  Purchases                            170.8
  Extensions and discoveries            46.8
  Net revisions                         16.6
  Sales                                (28.1)
  Production                           (32.0)
Total proved reserves, 12/31/04        299.0

All of the purchases of proved reserves in 2004 were related to the acquisition of Southwest Royalties, Inc. in May 2004. More than half of the extensions and discoveries for 2004 were attributable to the Company's exploration program in south Louisiana. Approximately 66% of the net upward revisions were attributable to improved well performance primarily from properties acquired through Southwest Royalties and the remainder was attributable to the effects of higher product prices on the estimated quantities of proved reserves.