bottom image

Exploration Model

Sulurian Reefs

    The Geneva Dolomite, commonly the basal member of the Middle Devonian Grand Tower Limestone in much of the Illinois Basin, is an exploration target that has recently generated much interest. In March of 2002, a new field discovery was completed under the Stephen A. Forbes State Park in Marion County, Illinois. The well has produced over 3 million barrels of crude oil and is still producing at rates above 500 BOPD. In Illinois the Geneva Dolomite is a prolific producer when found high on structure with closure. Typically, the Geneva is found as a drape over older Silurian Reefs.

    Historically, the Geneva Dolomite produces from 150,000 barrels of oil to as much as 2.5 million barrels per well. Until 1976, when the majors left the Illinois Basin, approximately 26 reefs had been found. The 1990's saw renewed interest with the discovery of the prolific Miletus Field in Marion County, Illinois. The field is expected to produce 5 to 6 million barrels of oil. The Stephen A. Forbes State Park is immediately south of the Miletus Field with reserves est. at 5 to 8 million barrels.

     The hunt for Silurian Reefs in the Illinois Basin offers the most exciting prospects for the discovery of multi-million barrel oil reserves. Through the early 1970's only 26 productive reefs had been discovered in the south central portion of Illinois. It was during that time that major oil companies were leaving the basin to go offshore and international.

    For the next thirty years the typical Illinois Basin producer stayed in their small areas of shallow production (3000 ft. or less) with an occasional well drilled to deeper depths to see what might be there. Consequently discoveries were made in the St. Louis, Salem, Warsaw, and the Devonian.

     In the late 1980's Dart Oil Co. discovered oil in the Geneva Dolomite using existing 2-D seismic and dip-log technology. These wells opened the Lillyville field in the northeastern portion of Effingham County and are still being developed today with the aid of 3-D seismic surveys.

     In the 1990's Cejas discovered the highly prolific Miletus Field in Marion County. Once again, the discovery of oil in the Geneva Dolomite fired the development of the field. After the discovery of oil in the Geneva Dolomite, a 3-D seismic survey confirmed the size and shape of the field and allowed further development.

     In 2002, a major Geneva Dolomite discovery was made, immediately south of the Miletus Field, at the Stephen A. Forbes State Park. Deep Rock Petroleum drilled a horizontal well-bore under the park and brought in a well flowing at rates as high as 10000 barrels of oil per day. The well was choked back to a production rate of 2000 bopd and flowed steadily through the casing for over a year.

     Production from Geneva Dolomite wells can be quite prolific. Per well cumulative production can be as high as 2.5 million barrels of oil. Very often these wells produce 300,000 to 500,000 barrels of oil in 3-4 years. Decline curves average about 6% per year.

    MDM Energy, Inc. has an aggressive exploration program for Silurian Reefs and the associated Geneva Dolomite drape. The company employs two consulting geologists and a geophysicist, all recognized leaders in Illinois Basin exploration. The team is dedicated to the discovery of new oil reserves in the Geneva Dolomite.

     The prospect generating process is simple. Find all of the scientific markers over existing Geneva Dolomite production and then find the matching signatures in new areas.

     Photo-geologic and geomorphic mapping, satellite imaging, geo-chem, seismic, gravity, and sub-surface mapping from nearby well logs are all employed as tools in the search for these reservoirs. MDM Energy, Inc. has identified several areas of potential Devonian reservoirs and has leased or is in the process of leasing these prospects for exploration.

     Once a new reservoir has been discovered and found to be productive, a 3-D seismic survey will be employed to delineate the size and shape of the reservoir. A thorough review of all data can then establish the most economical method of exploitation of the field.

New or Overlooked Reservoirs

    MDM Energy, Inc. employs several methods of exploration in the search for new or overlooked areas. Normally, once an area has been identified from standard geological methods (ie. nearby well logs, coal tops, geomorphic mapping, gravity surveys, etc.), the company attempts to find and purchase old seismic lines that may be available. Once aquired, the data can be re-processed, using todays more advanced computer technology. Often the re-processing of sometimes 25 and 30 year old data, may reveal structural subtleties that might have been overlooked with the original processing of the data.

     If necessary, new lines may be run to verify the data. Once all the scientific data has been collected and organized, a detrmination is made whether or not to proceed with a test well. If the test well is successful, field development begins.

    This method was employed by the company in Effingham county and resulted in the discovery of the Mason Northeast field. The field consists of shallow oil wells (less than 3000 ft.) with multiple pay zones, Roseclair SS, and McCloskey Oolites (lime). The deeper horizons are scheduled for exploration later this year.