Statistically, 1955 developments were comparable with the previous year, except for the increased exploratory drilling. The discovery ratio remained approximately the same. No major reserves were indicated from these new discoveries, but reserves increased substantially from extensions and new pays.

Development drilling decreased 6% in 1955.

Exploration drilling increased 19%, reflecting the faith operators have that new substantial reserves will be found.

In all, 627 wells were completed as producers.

Major reserve increases came from extensions of old fields rather than new fields.

Of the important new discoveries, 10 were new fields, 9 deeper pools, and 2 shallow pools.

Twenty-seven of the new producers were in the Lower Cretaceous, 7 in the Upper Cretaceous, and 2 in the Jurassic.

Geophysical activity decreased 4% from the previous year. Seismic, gravity-meter, magnetometer, and core-drill work amounted to 1,341 crew-weeks.