Total drilling activity in Mississippi, Alabama, Florida, and Georgia, including both exploratory and development wells, decreased 33.4% from 1,053 wells in 1985 to 701 wells in 1986. Exploratory drilling in 1986 in the southeastern states decreased 47.6%. Of the 215 exploratory tests in 1986, 51 were successful for a 23.7% success rate. This compares to 1985's 82 successful completions of 410 tests and a 20.0% success rate.

The Paleozoic trend of northeastern Mississippi and northwestern Alabama accounted for 32.1% of the exploratory tests. This active trend had 16 new-field discoveries in 1986 compared to 24 new-field discoveries in 1985. The Jurassic trend, with 22.8% of the total exploratory effort, had 11 new-field discoveries in 1986 compared to 14 new-field discoveries in 1985. The shallow Eocene Wilcox trend in southwestern Mississippi had 7 new-field discoveries in 1986 compared with 12 in 1985, and represented 22.3% of the exploratory effort. The Upper Cretaceous, Lower Cretaceous, and Miocene trends accounted, respectively, for 13.5%, 7.4%, and 1.9% of the total exploratory tests. Four new-field discoveries were reported in the Upper Cretaceous, only 1 in the Lower Cretaceous, and 3 in the Mioc ne.