A total of 4,572 wells was drilled in eastern New Mexico and west Texas during 1978--6.7% fewer than in 1977. The success rate for all wells was 78.8%, identical with 1977. The number of exploratory wells drilled was 16.9% fewer than in 1977, but total exploratory footage drilled was down only 5%. The exploratory success rate increased by 2.8% to 36.4%. Seismic-crew activity increased 15.9% from 1977 continuing an upward trend. Seismic activity is usually a reliable indicator of trends in exploratory drilling; therefore, a new increase in wildcat drilling is predicted for late 1979 and 1980.

During 1978 4.3% fewer development wells were drilled, but total development footage increased 3.1% to a record 23,199,275 ft. Development success rate decreased 1.9% to 87.3%. Oil production for 1978 was 669,441,101 bbl, down 3.9% from 1977 and down 10.4% from the all-time high of 747,467,187 bbl in 1973. Despite this decline, oil production from west Texas and eastern New Mexico still represents approximately one-fifth of total United States production.