Some observations on Simpson Group production in the Eola-Robberson field, Garvin County, Oklahoma
The Simpson Group in the Eola-Robberson field, Garvin County, Oklahoma has produced nearly 100 MMBO and 125 MMCFG since its discovery in the Sohio #1 Howard well in 1947. At least 10 different structural blocks within the field produce from the Simpson. Using field nomenclature, the Bromide Dense, Upper Bromide/2nd Bromide(Basal Bromide of Tomlinson's measured Simpson section on Oil Creek), Basal Bromide/3rd Bromide(Basal Tulip Creek of Tomlinson's measured Simpson section on Oil Creek), Upper McLish, Basal McLish and Basal Oil Creek produce in the Eola portion of the field. The Birdseye Limestone in the Upper Oil Creek formation produces in a few wells in the Robberson buried hill portion of the field. Original hydrocarbon columns vary from 500′ to 3,500′ with different oil water contacts in each zone in each block. The West Eola block had initial gas caps in each zone, as did the Basal McLish in the South block; the other reservoirs had no initial gas cap. Because of the small water legs in most of the blocks, there are very few reservoirs with even weak water drives, necessitating secondary recovery in much of the field. Several wells have drilled previously bypassed blocks in the past decade with good results. Modern wire line tools have also helped document significant bypassed and stranded reserves. Maps and cross sections show the complexity and potential for exploring for other fields that may be concealed in the major fault zones of Southern Oklahoma.
AAPG Datapages/Search and Discovery Article #90221 © 2015 Mid-Continent Section, Tulsa, Oklahoma, October 4-6, 2015