OKLAHOMA (EXCLUDING PANHANDLE)

Exploratory drilling in Oklahoma in 1964, in all categories except outposts, remained essentially unchanged from 1963. Development drilling showed an increase of 24 per cent. Total wells in all categories (4,005) were up 17 per cent from 1963, the first time since 1959 that this figure has exceeded 4,000. The over-all success ratio was 66.9 per cent, slightly lower than in the previous year. The ratio of 25.9 per cent for new-field wildcats is far above the national average, as is the success ratio for new-pool wildcats (42.5 per cent). This remarkably high success rate probably is the result of the almost universal application of geology in selecting drill sites. Petroleum geology flowered in Oklahoma and that State continues as a stronghold of the science.

Wildcat drilling was concentrated on the northeast shelf of the Anadarko basin with more than 59 per cent of all discoveries (129 out of 218) being in that area. Mississippian limestone is the principal reservoir rock; most of the porosity and probably much of the trapping are the result of fracturing.

Seventeen new fields and new pools were discovered in the Oklahoma portion of the Arkoma basin. Most significant was the discovery of large reserves of gas in the Hunton and Simpson on the Milton anticline.

TEXAS-OKLAHOMA PANHANDLES

There were 1,156 wells drilled in the Texas-Oklahoma Panhandles during 1964. This represents a 16 per cent decrease from 1963. Exploratory footage remained stable, being down only one per cent. Geophysical activity was down 10 per cent. However, new discoveries in Lipscomb, Hemphill, and Wheeler Counties hold promise for the petroleum industry in this area for many years. Leasing activity was relatively unchanged and probably will remain so, barring a discovery in either the Palo Duro or Dalhart basin.