The year 1938 marked another twelve months' period during which the volume of newly discovered petroleum reserves in Oklahoma failed by a substantial margin to offset withdrawals. Total production of oil for the state during 1938 was approximately 170,000,000 barrels, a decrease of 23 per cent from the total for the preceding year. There were approximately 2,000 wells completed during the year, representing also a decrease of 30-35 per cent from the total well completions for 1937. The seismograph continued to be the chief exploratory method employed in the search for new structures, but there was a 20 per cent reduction in the average number of crews as compared with the preceding year. The majority of these crews were engaged in closer detail work in areas already fairly intensively explored. There was very little decrease in wildcat drilling operations. Of the 2,000 well completions 220, or 11 per cent, might be classified as exploratory wells. By far the greater number of these were located adjacent to producing pools in the central part of the state. As a result of the drilling of these 220 wildcat wells, 42 new producing areas were discovered. Of this total 16 might be considered as extensions to known pools and 26 as new pools. Thirty-nine of the discovery wells produced oil and 3 produced gas. Pennsylvanian sediments accounted for the production in 19 of the discoveries. Siluro-Devonian in 4 wells, and Ordovician in 19 wells. It is unfortunate that by far the greater number of the discoveries reveal as yet only relatively unimportant reserves. The outstanding discoveries as indicated by development to date were the Ramsey pool, in Payne County, and the Alma Oil Company extension to the St. Louis pool, in Pottawatomie County. Developments subsequent to discovery around outlying wildcats at Noble, in Cleveland County, and at Hillsdale and Waukomis, in Garfield County, have been disappointing. Drilling activities in the older pools of the state were largely routine, with the Seminole-St. Louis areas furnishing the greatest number of completions. The Oklahoma City pool continued to lead the state in output, with an annual production during 1938 of 38,796,000 barrels. The Fitts pool with 16,655,000 barrels rank d second.