Drilling and production declined during 1957. There was a marked decrease in the total number of wells drilled, but the percentage of successful completions was about the same as the previous year. Frio and Yegua formational trends had the largest number of wells drilled. Very little drilling was done on the Continental Shelf.
Oil production declined for the first time in several years, although gas production continued to increase.
Forty new oil and gas fields were discovered during 1957. There were slightly more gas fields found than oil. Most discoveries were in the Frio and Yegua formational trends. Anticlinal closures accounted for most of the discoveries.
Exploration declined during the year. The largest drop in exploratory work occurred on the Continental Shelf. Exploration and drilling in 1958 will be less than during the past year.