Comstock Resources is a growing independent energy company based in Frisco, Texas, engaged in oil and gas acquisitions, exploration and development. We have a solid record of growth in oil and gas reserves and production driven by both successful acquisitions and by a successful exploration and development program.
Our oil and natural gas operations are focused in two primary operating areas, the East Texas/North Louisiana and South Texas regions. In addition, we have properties in Arkansas, Kansas, New Mexico and Oklahoma. In May, 2013 we divested all of our oil and gas properties in West Texas.
Much of our historic growth has come from acquisitions of producing oil and gas properties. In recent years our growth has also come from the drill bit. Since 1991 we have acquired 1.1 trillion cubic feet equivalent ("Tcfe") of proved oil and gas reserves in 38 transactions at an average cost of $1.17 per thousand cubic feet equivalent ("Mcfe").
As a result of our acquisition, exploration and development activities, we have assembled a high quality, geographically focused reserve base. Our geographic focus allows us to have specific geologic and engineering expertise in the regions we operate which contributes to the success we have had in our acquisition and drilling activities. Our reserve base at the end of 2012 (excluding our discontinued West Texas operations) was 551 Bcfe. These reserves were 79% natural gas, 21% crude oil and were 75% developed.
Our properties have an average reserve life of 6.0 years and have extensive developmental and exploration potential remaining.
Our business strategy is to continue to build shareholder value by exploiting our existing reserve base, pursuing exploration and acquisition opportunities in our core operating regions, maintaining an efficient cost structure, and having substantial financial flexibility.
We are presently focused on growing oil reserves on our properties in South Texas. During 2012 our drilling program for our continuing operations grew our oil production by 114%, mainly from continued exploration and development on our Eagle Ford shale properties in South Texas. During 2012, we spent $347 million on exploration and development activities, including $256 million to drill 37 (23.7 net to us) wells, $71 million to complete 20 wells that we drilled in 2011, $14 million to acquire additional leases, and $6 million on seismic data, recompletions, workovers, abandonments, production facilities and developmental leasehold. For 2013, our capital budget is $347 million, $312 million of which we plan to spend on oil focused projects in South Texas to drill 72 (46.9 net to us) wells targeting the Eagle Ford shale and to complete six (2.8 net to us) wells that were drilled in 2012. We also plan to spend $35 million during 2013 to drill 10 (3.6 net to us) wells in the Haynesville/Bossier shale formations and in our other regions. We have also budgeted $12 million to acquire additional leasehold interests during 2013.
The last element of our business strategy is to manage our balance sheet to insure that we have substantial financial flexibility to execute our business plan. We strive to fund our drilling activities primarily with operating cash flow. Following our recent divestiture of our West Texas properties in May 2013, we have a very strong balance sheet.