Wells drilled in the Upper Texas Gulf Coast during 1981 totaled 2,502, up 37% from the 1980 total of 1,826. Onshore development drilling accounted for 76% of the total with 1,910 wells, a 36% increase over the previous year. Onshore exploratory drilling also had a 37% increase, with 581 wildcats drilled in 1981 compared with 420 wildcats drilled in 1980. There were 65 successful new-field discoveries in 1981 with an average depth of 10,549 ft and a success rate of 19.6%. The Oligocene trend remained the most active exploration trend with 44% of the wildcats; however, the Eocene trend, particularly the Yegua Formation, was the target of the most significant discoveries. Offshore, exploratory drilling decreased dramatically by 54% with only 42 wells drilled compared with 90 the previous year. Offshore development drilling increased 27% in 1981 with 88 wells drilled compared with 64 in 1980.

Onshore, geophysical activity decreased slightly with 1,064 crew-weeks worked compared with 1,174 crew-weeks in 1980. Offshore geophysical activity also decreased with only 97.5 crew-weeks worked compared with the 156 crew-weeks of the previous year. In 2 state lease sales and 1 federal lease sale held in 1981, the industry spent $1.13 billion to acquire 476,530 acres.