ABSTRACT

A large high salinity groundwater anomaly was investigated in southern Oklahoma using spontaneous potential (SP) well logs. The NaCl anomaly is located in Pennsylvanian Garber sandstones off the south flank of the giant Sholem Alechem oil field in western Carter and eastern Stephens counties. 268 oil well logs run in wells with short surface casing were digitized and total dissolved solids was computed for each bed. Lack of sufficient water well data necessitated this indirect approach.

The SP data had to be corrected extensively to yield reliable results. Both geometric and chemical calibrations were performed. Local equivalent water resistivity--true water resistivity and equivalent mud filtrate resistivity--true water resistivity functions were used, and the data were computer corrected for borehole geometry, bed thickness, and resistivity effects.

Isopachs of the salinity anomaly were integrated yielding an excess of salt over the regional background salinity of = 1.7 times the total estimated salt production from all the surrounding oil fields. The Arbuckle orogeny in the late Pennsylvanian rejuvenated the Camp-Milroy oil field structure to the south of the anomaly. A conglomeratic fan developed, shutting off the basin to the west. The fan remained a positive ridge during the Permian, trapping the newly flushed Garber salt in the syncline.