The year 1955 was the most active year in the history of the area, with 6,046 wells being drilled. Production was also the highest in history, with 489,200,888 barrels of oil being produced. Exploratory wells totaled 1,157, the highest number ever drilled. Success ratio for all exploratory wells was 36%; the ratio for new-field wildcats was 20%. The most important discoveries were in the Queen sand of northern Andrews and southern Gaines counties, Waddell sand of western Crane County, the Grayburg-San Andres of southeastern Reagan and northern Crockett counties, Clear Fork sand of southwestern Irion County, Ellenburger of the Sheffield area of eastern Pecos County, and the King Mountain Ellenburger field of western Upton County. Exploratory methods continued the same patterns as in previous years with a concentration of interest in older producing areas. Seismic and gravity activity held steady while core drilling on the Eastern shelf decreased slightly. The concentration of interest in the most promising parts of the area combined with the lack of availability in those areas resulted in bonus price increases, overrides, oil payments, and some seismic option-type deals. Acreage is being dropped in those areas considered least promising.