Onshore drilling in the upper Gulf Coast of Texas during 1987 totaled 822 wells, a 19.8% decrease from 1986's total of 1,025 wells. Exploratory drilling declined 17.5%, and development drilling decreased 20.5% from 1986. Twenty-two new-field discoveries resulted from drilling 123 new-field wildcat wells in 1987, for a 17.9% success rate. Forty-five other wildcat discoveries resulted from drilling new-pool, deeper pool, or extension wells, with a 64.3% success rate.

The Eocene trend was the most active exploratory trend onshore with 38.9% of the onshore drilling; the Oligocene and Cretaceous trends had 27.4% and 26.4% of the onshore exploration activity, respectively.

Offshore exploratory drilling in 1987 totaled 64 wells, an 18.5% increase from 1986. Development drilling offshore declined 51.0% with 50 development wells drilled in 1987 compared to 1986's total of 102 wells. The exploratory success rate offshore was 17.2%. Exploration activity resulted in 6 new-field discoveries and 5 new-pool, deeper pool, or extension discoveries. Fifty-three exploratory dry holes were drilled offshore in 1987.

Offshore, the Miocene trend was most actively explored, receiving 59.4% of the exploratory drilling in 1987.