This report, the eleventh based on data gathered by the Committee on Statistics of Exploratory Drilling, is the twentieth annual summary on the subject prepared by the author. A brief history of this undertaking is presented. With many thanks to those who have assisted him, and to the Sun Oil Company and the Humble Oil and Refining Company, the author now bows out as chairman of the C.S.E.D. and leaves the task to his successor, Graham B. Moody, who has long served as vice-chairman of this committee and as chairman of the California subcommittee.

During 1955, 14,937 exploratory holes were drilled in the United States. Of these 8,104 were new-field wildcats, 3,629 were new-pool tests (including new-pool wildcats, deeper-pool tests, and shallower-pool tests), and 3,204 were outposts. Among the new-field wildcats, 918 were successful; among the new-pool tests, 1,069 were successful; and among the outposts, 1,118 were successful.

The total exploratory footage drilled in the United States in 1955 was 69,173,209 feet in the 14,937 holes, or 4,631 feet per hole. These figures are comparable with 59,581,038 feet drilled in 13,097 exploratory holes, with an average depth of 4,549 feet in 1954. For the eighth time, we are presenting data on Canada and Mexico.

Because the summary of the data gathered annually by this committee is the most reliable analysis available of the Industry's exploratory drilling for oil and gas, and because the facts presented in this analysis demonstrate the high degree of risk in exploratory drilling and, therefore, the need and fairness of the 27½ per cent depletion allowance, the work of the committee must go on without interruption in time or omission of any district.