Oil and gas producer XTO Energy has announced that Miller and Lents, an independent petroleum engineers firm, estimates XTO's proved oil and gas reserves at December 31, 2007 to be 11.29 trillion cubic feet of gas equivalent, up 32%, compared with 8.55 trillion cubic feet of gas equivalent at December 31, 2006.

Natural gas reserves increased 36% to 9.44 trillion cubic feet of gas equivalent (Tcfe), and natural gas combined with natural gas liquids of 67 million barrels equaled 87% of total reserves.

Oil reserves increased 13% to 241 million barrels. Proved developed reserves accounted for 66% of total proved reserves on an equivalent basis.

During 2007, XTO Energy added 3.41Tcfe at a cost of $2.03 per thousand cubic feet of gas equivalent (Mcfe), replacing 513% of production. The company’s development program replaced 308% of production or 2.05Tcfe at a cost of $1.64 per Mcfe. Excluding unproved property additions from leasing activities, development costs were $1.36 per Mcfe.

Bob Simpson, XTO Energy’s chairman and CEO, said: These results highlight the strength of XTO’s property base and the efficiency of our ongoing development campaign. As we look ahead, our teams are confident in the company’s resource potential and have defined growth plans.