Oil and gas have been commercially produced in Illinois for over 100 years. Existing commercial production is from more than 52 named pay horizons in Paleozoic rocks ranging in age from the middle Ordovician to Pennsylvanian. Over 3.2 billion barrels of oil have been produced. Recent calculations indicate that remaining mobile resources in the Illinois Basin may be as much as 4.1 billion barrels. Thus, large quantities of oil, potentially recoverable using current technology, remain in Illinois oil fields despite a century of development. Opportunities for increased production may have been missed due to complex development histories, multiple stacked pays, and commingled production. These factors make thorough exploitation of pays and the application of secondary or enhanced recovery strategies difficult. Access to data, and the techniques required to evaluate and manage large amounts of diverse data, are major barriers to increased production of critical reserves in the Illinois Basin.

The Illinois Oil and Gas (ILOIL) project was designed to alleviate data access constraints by developing new techniques for evaluation and identification of underdeveloped areas (UDAs) in and around petroleum reservoirs in Illinois. The Illinois State Geological Survey (ISGS) statewide oil and gas Oracle database was used to develop a series of oil and gas base maps with well location symbols that are color-coded by producing horizon. These maps can be presented either as a single pay horizon or layered to show multiple producing horizons.

A second series of pay horizon maps that identify underdeveloped areas have been generated from a statewide waterflood database. Pay analysis maps that identify reservoir quality and specific pay characteristics have also been developed from a statewide core analyses database. In combination, these underdeveloped pay area identification tools constitute a powerful analytical technology that incorporates all pays within the State of Illinois.

• UDA Evaluation Techniques
• ILOIL Interactive Map
• ILOIL Waterflood information Power Point

The ILOIL map service was developed by the Illinois State Geological Survey and funded by United States Department of Energy (DOE) contract DE-FC26-02NT15132 through the National Energy Technology Laboratory (NETL). Visitors can query and display well database attributes and create custom map views for printing. Kentucky and the Appalachian Region also have oil and gas resources Web mapping projects.

Contact Beverly Seyler for more information, or to send comments, about the ILOIL project web resources.