During 1965 there were 359 wells drilled in Arkansas, a decline of 7.9% from 1964. Of the successful completions, 113 were oil productive and 46 were gas productive. From these successes, 8 new oil fields, 2 new gas fields, and major extensions to 3 gas fields were established. All of the gas discoveries and extensions were in the Arkoma basin of northern Arkansas. The overall drilling program in Arkansas was 44.3% successful; wildcat wells were 12.0% successful. Total footage drilled was 1,530,240, a decline of 4.5% from 1964. Increased geophysical activity and strong leasing activity indicate an increase in exploratory drilling in 1966.

In North Louisiana, 2,640 wells were drilled, 299 less than in 1964. There were 1,220 oil wells completed, 300 gas wells, and 1,120 dry holes. Wildcatting accounted for 348 completions. Total footage drilled was 9,854,958, an increase of 1,171,028 ft. from 1964. The number of fields discovered was much less than the number for 1964. A total of 13 new oil fields and 2 new gas fields was discovered, compared with 22 oil fields and 6 gas fields for 1964. There were 8 oil fields discovered in Concordia Parish, 2 in LaSalle, 1 in Caddo, 1 in Catahoula, and 1 in DeSoto. Gas discoveries were made in DeSoto and Sabine Parishes. Eleven of the oil discoveries were in the Wilcox Group reservoirs, and 1 each was in the Paluxy Sand and Pettet Formation. Two gas fields were discovered in reservoirs of the Tuscaloosa and Tokio Formations. Increased geophysical work and much stronger leasing activity indicate an increase in exploratory drilling in 1966.

In East Texas, 229 wildcats and 824 field wells were drilled, an increase of 49 wells above 1964. However, new-field discoveries totaled only 15, a decrease of 6. New-pool discoveries made a substantial gain, but geophysical activity and acreage acquisition decreased. The major interest continues to be in the Smackover trend and in field development in the Sabine uplift area.