Three hundred seventy-nine wells were completed in Mexico during 1958, as compared with 389 drilled during the previous year. However, the average depth per well increased from 6,463 ft. to 6,958 ft. for a total footage of 2,636,900 ft., an increase of 122,735 ft. over the total footage drilled during 1957. Seventy-six wells were classified as exploratory holes, 17 of which were successful (22%). Fifty-five new-field wildcats were drilled and new reserves were added through the discovery of 4 new oil and/or gas fields, 12 new pools, and 1 extension to a previously producing field. Of the total number of wells, 285 were successful (75%).

Two new gas fields were located in the Eocene and Oligocene trends of Northeastern Mexico, one oil field was found in the Poza Rica district, and a fourth oil field was found in central Tabasco in southern Mexico.

The bulk of the exploratory effort was concentrated in the coastal plain of the Gulf of Mexico, where all the producing fields are located; however, gravity and seismic work continued in the Baja California and Yucatan peninsulas and in Chihuahua in north-central Mexico. In northeastern Chihuahua an unsuccessful deep exploratory test was completed during this year.

Several tests were drilled to the Cretaceous and Jurassic in Northeastern Mexico, and in the Tampico Embayment most exploratory wells penetrated the Upper Jurassic formations which produce in the Constituciones and San Andres fields.

In the Veracruz Embayment drilling activity decreased considerably and will be followed by a campaign of deeper wells to test the Middle and Lower Cretaceous sediments, as yet unproductive in this area.

Production in the Isthmus and Tabasco region increased 7,000 bbls. per day during the year. This increase being due to the development of the La Venta and Ogarrio fields and the completion of the absorption plant in the Macuspana district.

Crude oil and distillate production for 1958 was 100,641,405 bbls. Total gas production was 262,626,152 MCF. This means an increase of 8.5 million bbls. of oil and about 100 millions MCF of gas.