Utilizing Horizontal Drilling to Enhance Oil Production from the Devonian Geneva Dolomite at Plummer Field, Indiana, and Its Application in Carbonate Reservoirs
Plummer Field, a characteristic reef-induced anticline, was discovered in 1969. There are three oil bearing units in the overlying “draped” strata: Mississippian McCloskey and Salem Limestones and Devonian Geneva Dolomite. The Geneva Dolomite is a member of the Jeffersonville Limestone, and it is characterized as chocolate brown, rather soft, granular, and vuggy. At Plummer Field the formation has a depth ranging from 1500 to 1600 feet. The primary oil-bearing zone has gross and net thicknesses of 15.4 feet and 8.9 feet respectively, with average porosity of 10% maintained laterally throughout the field. Original oil in place is 6.6 MMBO. Production thru April 2014 totaled only 0.75 MMBO with a daily average of 30 BOPD from 40 wells. It is assumed, the low cumulative production value is due to poor connectivity of the vugular porosity. In May 2014 a horizontal test, Patterson-Schaar- Hemmerlein #4-H, was completed without stimulation and had an IP of 268 BOPD flowing. In December of that year two more horizontal wells were completed with IPs of 587 BOPD and 450 BOPD pumping. These three wells were drilled between active and plugged vertical Geneva oil wells, and no production loss was monitored in nearby producing wells. Since completion three years ago these three wells have produced over 140,000 barrels of oil accounting for 15% of the total oil production from the Geneva. Though the Geneva had been producing for 45 years at Plummer Field, the new horizontal wells proved very successful, and as a result, further drilling is planned for the approximately two square mile field. It is believed that this method could be applied to other mature fields containing thin (less than 10 feet) and laterally continuous carbonate reservoirs.
AAPG Datapages/Search and Discovery Article #90335 © 2018 AAPG 47th Annual AAPG-SPE Eastern Section Joint Meeting, Pittsburgh, Pennsylvania, October 7-11, 2018