The Upper Gulf Coast of Texas is composed of 26 counties in the southeastern part of the state. It is identical with Texas Railroad Commission District 4, omitting Fayette and Lee counties.

There were 1114 wells drilled in the district in 1948, which is a 27 per cent increase over 1947. Of these, 212 were wildcat tests drilled in search of new structures. This represents an increase of 14 per cent over 1947 and resulted in the discovery of 22 new fields as compared with 20 new fields in 1947. These new discoveries consisted of 9 oil fields, 10 gas-condensate fields, and 3 gas fields. All are of minor importance, the Lane City Townsite field, Wharton County, being the most important. First production was discovered in Jasper County, Buna field, and a new Cretaceous producing zone was found in Trinity County, in the northwest Glendale field.

Considerable more reserves were added by development in old fields. Nine hundred two wells were drilled on known structures, which resulted in the discovery of 77 new sands, 31 new reservoirs, and 22 important extensions. This is a considerable increase over 1947. Most of these additions to reserves were the result of the discovery of new fault segments and new sands on old salt domes.

Two wildcat wells were completed as dry holes in the Gulf of Mexico, one of which is believed to have discovered a new salt dome 18 miles southeast of Galveston.

First production was established on an interior salt dome in Madison County.

Forty seismic reflection parties were operating at the end of the year as compared with 35 at the first of the year. The most active counties were Brazoria, Matagorda, and Wharton, with some work being conducted on offshore leases.

Total oil and condensate production in 1948 amounted to 197,055,000 barrels, which is an increase of 6 million barrels over 1947.

The reflection seismograph, in conjunction with subsurface geology, was the most successful exploration method.