Again in 1957 activity in the Louisiana Gulf Coast was greater than in the preceding 5 years. In all, 2,317 tests were drilled, 845 of which were exploratory tests (33.8% successful) and 1,472 of which were development wells (79.2% successful). Oil production showed an increase of 11% during 1957 and gas production an increase of 14%. However, the 55 new-field discoveries indicated a decrease of 23.6% from the 72 new fields found in 1956. Montegut, Terrebonne Parish, is the most important new-field discovery. The southward extensions of the Bastian Bay field, Plaquemines Parish, were the most important onshore developments. The new-pool discovery at Ship Shoal Block 28 constituted the most significant addition to offshore reserves. There were also 169 new pools and 62 extensions to known fields discovered in 1957.
Seismic activity during 1957 showed a decrease of 8% from the previous year. Reflection seismograph was used in the discovery of 54 of the 55 new fields in the Louisiana Gulf Coast. There was an increase in the use of subsurface geology and the core drill. Gravity activity continued to show a slight decrease in 1957.
Miocene sands were the objectives of the majority of the exploration effort. Terrebonne Parish was first with ten new-field discoveries. The average depth of successful new-field wildcats was 12,660 feet. Federal and State leasing of offshore lands in the disputed zone has been discontinued pending the settlement of the United States-Louisiana tideland controversy.