In February, 1965, the South Alex and Chitwood producing areas were consolidated and designated Chitwood. These two Bromide producing areas are closely related geographically and geologically, and both are included in this discussion. Emphasis of this discussion is placed on the deeper producing Simpson rocks.

Even though there is this close relationship, geological and reservoir data indicate that the two areas are separate. Based on structural data from subsurface and seismograph, the two producing areas are located on separate anticlines. This interpretation is supported by differing condensate ratios in the wells of the two sectors.

Production ranges in depth from 15,908 to 17,202 ft.; Oklahoma's deepest productive well is located in the South Alex part of the field.

Production capabilities of the wells appear to be related directly to porosities and permeabilities which change significantly from well to well. The changes are sufficiently great that wells range from very good producers to dry holes.

Data from petrographic analysis indicate a small amount of pressure solution and a large amount of secondary silica growth. Both factors decrease original porosity of the reservoir.

Predicting the presence or absence of porosity is a most difficult problem. Extremely high drilling costs make it necessary to drill a minimum number of dry holes. Subsurface control from 640-acre spacing leads to unreliable development predictions.

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