Exploracion y prod reservas

Exploitation and Optimization of Reservoir Performance in Hunton Formation, Oklahoma

ANNUAL TECHNICAL PROGRESS REPORT

Reporting Period October 1, 2002 – September 30, 2003 Principal Investigator Mohan Kelkar, The University of Tulsa Report Issued October 2003 DOE Award No. DE-FC26-00NT15125

Submitted By Mohan Kelkar Department of Petroleum Engineering The University of Tulsa 600 S.College Ave., KEH #L-117 Tulsa, Oklahoma 74104-3189

http://www.tucrs.utulsa.edu/Hunton

Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness,or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or anyagency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

The University of Tulsa DE-FC26-00NT15125

ii 18 December 2003

Acknowledgements The research effort described in this report was supported by the U.S. Department of Energy under Contract No. DE-FC26-00NT15125. Additional supportis provided by Marjo Operating Company, Inc., the University of Houston, Joe Podpechan and James R. Derby and Associates, Inc. The computer facilities were provided by The University of Tulsa. We would like to thank Brian Keefer from Marjo Operating Company, Inc. for his valuable contribution and insight to our work. Our special thanks also go to Paul West from the Department of Energy for theirenthusiasm and valuable suggestions. October 2003 Mohan Kelkar

The University of Tulsa DE-FC26-00NT15125

iii 18 December 2003

Abstract This report presents the work done so far on Hunton Formation in West Carney Field in Lincoln County, Oklahoma. West Carney Field produces oil and gas from the Hunton Formation. The field was developed starting in 1995. Some of the unique characteristics ofthe field include decreasing water oil ratio over time, decreasing gas-oil ratio at the beginning of production, inability to calculate oil reserves in the field based on log data, and sustained oil rates over long periods of time. To understand the unique characteristics of the field, an integrated evaluation was undertaken. Production data from the field were meticulously collected, and overforty wells were cored and logged to better understand the petrophysical and engineering characteristics. Based on the work done in this budget period so far, some of the preliminary conclusions can be listed as follows: • • Based on PVT analysis, the field most likely contains volatile oil with bubble point close to initial reservoir pressure of 1,900 psia The initial oil in place, which is contactwith existing wells, can be determined by newly developed material balance technique. The oil in place, which is in communication, is significantly less than determined by volumetric analysis, indicating heterogeneous nature of the reservoir. The oil in place, determined by material balance, is greater than determined by decline curve analysis. This difference may lead to additional locations forin fill wells. The core and log evaluation indicates that the intermediate pores (porosity between 2 and 6 %) are very important in determining production potential of the reservoir. These intermediate size pores contain high oil saturation. The limestone part of the reservoir, although low in porosity (mostly less than 6 %) is much more prolific in terms of oil production than the dolomite...