MAJOR
STRUCTURAL FEATURES
The most significant structures within the
Illinois Basin are the LaSalle anticlinal belt, the DuQuoin monocline, and the
Cottage Grove-Rough Creek-Shawneetown fault system.
STRATIGRAPHY
The Basin contains primarily sedimentary rocks ranging from Cambrian
to Pennsylvanian in age. A small section of Permian sediments are
preserved in a graben in Union County, Kentucky. Limited areas of
Cretaceous and Tertiary deposits occur in western and southern Illinois.
Most of Illinois and Indiana are covered by Pleistocene glacial
drift. Major unconformities are Precambrian-Cambrian, middle Ordovician,
middle Devonian, Mississippian-Pennsylvanian, and Pennsylvanian-Pleistocene.
THICKNESS
The deepest point occurs in
the area of Union and Webster Counties, Kentucky, where the Paleozoic sediments
reach a thickness of over 20,000 feet. ECONOMIC
GEOLOGY
Products include oil and natural gas, coal, lead, zinc,
limestone, gravel, fluorite, and gypsum.
OIL AND GAS HISTORY
|
First
Oil Production
|
1889 (Vigo
Co., Indiana)
|
|
First
Gas Production
|
1863
(Meade Co., Kentucky) |
| First
"boom" |
1905
- 1915 (discovery of anticlines) |
| Second
"boom" |
1937
- 1943 (seismic, stratigraphic traps) |
| Third
"boom" |
1954
- 1964 (fracing, waterflooding) |
| Fourth
"boom" |
1980
- 1986 (oil prices) |
| Peak
year |
1940
(157 million barrels) |
| Secondary
recovery |
initiated in early 1940's |
| Number
of pays |
over
60, from Ordovician to Pennsylvanian |
SOURCE
OF OIL PRODUCTION
By
System:
Upper Mississippian (Chesterian)
|
60% | | Ste.
Genevieve Limestone (Valmeyeran) | 18% | | Pennsylvanian | 13% |
By
Lithology: | | | Sandstone
| 75%
| | Carbonates
| 25%
|
By
State: | | | Illinois
| 80%
|
OIL
AND GAS STATISTICS
| Average
well spacing | 10
- 20 acres | | Well
spacing below 4000' | 40
acres | | Estimated
original oil in place | 12
billion barrels | | Historic
Oil production |
4.5
billion barrels |
| Historic
Gas production | 4
trillion cubic feet | | Estimated
future recoverable reserves | 4.1
billion barrels |
| Current
Oil production |
15.2
million barrels (2004) |
| Overall
recovery efficiency | 36%
(highest in onshore U.S.) | | Percentage
recovered by secondary recovery | 33%
|
LARGEST
FIELDS
Lawrence
Location: Lawrence Co., Illinois
Discovery: 1906
Geology:
LaSalle Anticlinal Belt
Production: 433 million barrels cumulative
Salem Consolidated
Location: Marion and Jefferson Co., Illinois
Discovery: 1938
Geology: Salem-Louden Anticline
Production: 402 million barrels cumulative
Louden
Location: Fayette and Effingham Co., Illinois
Discovery: 1937
Geology: Salem-Louden Anticline
Production: 396 million barrels cumulative
Clay City
Consolidated
Location: Clay, Wayne, Richland and Jasper Co., Illinois
Discovery: 1937
Geology: Clay City Anticline
Production: 371 million barrels cumulative
Main Consolidated
Field
Location: Crawford and Jasper Co., Illinois
Discovery: 1906
Geology: LaSalle Anticlinal Belt
Production: 265 million barrels cumulative
DEEPEST
WELLS Illinois
14,942' |
Mary
L. Streich #1, Texas Pacific Oil
Pope Co., 1976
D & A
| Indiana
8,429' | Mike
Hasting #1, Kestrel Resources / Team Energy LLC
Posey Co., 1998
IP 32
BOPD from Devonian Dutch Creek (5164-72') and Mississippian Ft. Payne (3892-3900').
| Kentucky
15,200' | Duncan
#1, Exxon Oil
Webster Co. 1977
D & A |
DEEPEST
PRODUCING PAY
Devonian Dutch Creek Sandstone at 5380 feet depth;
TD of 5405'.
Gray Estate #8, Moore Engineering, Mill Shoals Field, White Co., Illinois, 1980
IP 408 BOPD |
