A general picture of oil development in Oklahoma during 1940 does not differ materially from the pattern established by the past several years.

Total withdrawals of oil for the state during 1940 amounted to 150,072,000 barrels, a decrease of only 2.3 per cent from the production of the preceding year. Drilling operations increased slightly with 2,100 wells completed during the year. The major part of all new development was concentrated in a relatively few counties in the east-central belt of the state embracing the Seminole plateau and adjoining areas.

The Oklahoma City and Fitts pools still continued to lead the state in total annual field output.

Exploratory work was maintained at a high level and there was a noticeable increase in the number of geophysical units in operation. Following the discovery of the Cumberland pool there was for several months a very marked concentration of geophysical exploration in the south-central part of the state.

Only 230 exploratory tests were drilled during 1940 as compared with 268 during the preceding year. On the other hand there was an increase in the total number of successful exploratory wells due largely to extensions and work-overs. Seventy-six new discoveries are listed. Of these 29 are classified as new pools, and 32 as extensions. Eleven resulted from plug-back operations and 4 from deeper drilling. Stratigraphic distribution of the new discoveries was as follows.

From Pennsylvanian sands there were 37 producers, from Ordovician 21, from Siluro-Devonian 14, from Mississippian 2, and from Permian 2.

While from the standpoint of large additional proved reserves there were no discoveries of outstanding importance, the number of pools of fair quality noticeably exceeded the record of the past 2 or 3 years. Among the discoveries which have resulted in the completion of ten or more subsequent wells are the Cumberland pool in Marshall and Bryan counties, the West Hewitt extension in Carter County, the East Cromwell pool in Okfuskee County, the Dill pool extension in Seminole and Okfuskee counties, and the Prague pool in Pottawatomie and Lincoln counties.

As in the several preceding years, new discoveries during 1940 did not maintain the level of proved reserves and annual withdrawals greatly exceeded the new reserves added.