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STATE Ift'f'O'Sj GEOLOGICAL SURVEY

3 3051 00003 5240

Digitized by the Internet Archive

in 2012 with funding from

University of Illinois Urbana-Champaign

http://archive.org/details/undiscoveredoilr106leig STATE OF ILLINOIS DWIGHT H. GREEN, Governor DEPARTMENT OF REGISTRATION AND EDUCATION FRANK G. THOMPSON, Director

DIVISION OF THE STATE GEOLOGICAL SURVEY

\l. \L LEIGHTON, Chief

CIRCULAR—No. 106

UNDISCOVERED OIL RESERVES IN ILLINOIS

By M. M. LEIGHTON

Reprinted from The Oil Weekly,

March 13, 1944

LOWER AND OIL POSSIBILITIES IN ILLINOIS

By STEWART FOLK

Reprinted from The Oil Weekly,

March 20, 1944

PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS

URBANA, ILLINOIS

1944

Undiscovered Oil Heserves In Illinois

Chances for finding substantial amounts of new oil by no

means exhausted, especially in stratigraphic type traps

By M. M. LEIGHTON

I LLINOIS has had two great periods good geological reason to believe that of oil development, one beginning in oil accumulations in stratigraphic traps 1905, the other in 1937. Of the total of exist in Illinois. The discovery of oil 1,022,000,000 barrels produced, 566,000,- pools of this type will depend upon 000 barrels, or half, came from fields geologic studies combined with large- discovered since 1936. scale systematic drilling programs. All but a fraction of one percent of Very probably more oil remains to this latter quantity came from fields be discovered in additional producing located in the area of "best possibili- formations, both above and below those ties," as recommended by the Illinois now productive. There have been sev- State Geological Survey in a map classi- eral instances where pay zones have fying oil and gas possibilities in Illinois been passed up and later brought in. which was prepared and exhibited in Also there are many pools producing 1930. This classification was based on a in the McClosky or shallower forma- review by Dr. A. H. Bell of the many tions in which no tests have been drilled well logs and other geologic data which below the Mississippian strata. the survey had accumulated over a In January, 1942, under a special ap- period of 25 years. The discovery of propriation for work connected with oil in the central part of the Michigan the war effort, the Illinois State Geologi- Basin in 1928 led to recognition of the cal Survey undertook studies of Penn- oil possibilities of the Illinois Basin, sylvanian strata encountered in drilling and accordingly the deep basin area oil wells, for the dual purpose of ob- was included with the area of "best taining information on the oil and coal possibilities" in the 1930 classification resources of the Pennsylvanian system. map. The old fields of Illinois produced some The same organization that prepared hundreds of millions of barrels of oil the classification map has been studying from Pennsylvanian sandstones, but the and aiding in the oil developments and amount so far produced from Pennsyl- has recently taken stock of the Illinois vanian strata in the new fields has been situation. It is convinced that the comparatively small, in spite of the fact chances for finding substantial amounts that nearly all the wells were drilled of new oil are by no means exhausted. completely through the Pennsylvanian Although no major pools have been system. For several years following the discovered for several years, many small new discoveries in 1937 most wells were pools have been found and continue to drilled rapidly through the Pennsyl- be found every month. In the past, vanian without saving samples or ob- major attention has been given to the taining an adequate log of the forma- finding of structural traps. When the tions drilled, and it is probable that reflection seismograph method began pay zones were sometimes passed up. to be used, it was natural that the Electric logs have proved to be of con- largest structures should be prospected siderable help in stratigraphic studies first. That is why large pools like Clay but alone they are inadequate to detect City, Salem, and Louden were brought oil zones or to determine thicknesses in early during the play. It may be that of coal beds not previously known. To no large pools of the structural-trap remedy this situation the survey has type remain to be discovered. However, obtained a portable laboratory which some of the world's largest oil accumu- makes it possible for staff geologists to lations, such as East Texas, are of the sit on key wells during the drilling of stratigraphic type, and these are not the Pennsylvanian strata in order to discoverable by the reflection seismo- make detailed drilling-time logs, to graph method now in use. There is collect and examine samples taken at - e> o frequent intervals and then to correlate obtained from older Ordovician and in the laboratory all the information Cambrian strata in the Mid-Continent from a well, including: the electric log. area raises the question as to the oil Up to date some 180 wells have been possibilities of rocks of the same age in logged in this manner, and the results Illinois. are being studied for the benefit of both In view of the present need for oil the oil and coal industries. and especially for supplies geograph- The new data from the key wells are ically near areas of large consumption, being assembled in structure maps and there is now a strong incentive to ex- cross-sections. It is planned that sub- plore these deeper strata in Illinois. surface studies of pre - Pennsylvanian Detailed studies of reservoir condi- strata will be made in the areas of the tions and production conditions in in- new Pennsylvanian structure maps. dividual pools are in progress. These These will be based on sample studies, have a two-fold use, first to help solve electric logs, and drilling-time logs production problems, especially in con- where available. The relation of pre- nection with secondary recovery by re- Pennsylvanian to Pennsylvanian struc- pressuring or water-flooding, and second ture will be given special atention. to aid in the interpretation of regional geology. This work involves the collec- Deeper Possibilities tion and testing of cores, the collection Because the oldest formation that has and analysis of oil, gas, and brine yielded commercial production of oil in samples, the measurement of reservoir Illinois is the Kimmswick ("Trenton") pressures, and the measurement of the limestone of Ordovician age it has been rates of withdrawal of the reservoir customary in much of the past test- fluids. drilling in Illinois to stop with the first The planning and execution of a porous zone in the "Trenton." A few program to explore for oil in strati- test wells have reached the St. Peter graphic traps, in the deeper formations, sandstone. There remains, however, a and in undeveloped shallow pay zones sedimentary section estimated to be should make use of all available scien- about 4000 feet thick below the St. tific data, both geological and geophysi- Peter which has not been tested in the cal. The Illinois State Geological Survey Illinois Basin. The lithologic character with its staff of technical experts, its and the structure of the pre-St. Peter laboratories, and its extensive files of strata in the basin is therefore unknown. data, is contributing its resources in The fact that large oil production is research to such a program.

Lower Ordovician and Cambrian

Oil Possibilities in Illinois

Production of large volumes from these formations in other states suggest commercial possibilities in southern two-thirds of state, where they constitute almost unexplored geological "layer"

By STEWART FOLK

B1 ELOW the St. Peter formation in Cambrian age. Equivalent strata in Illinois are many hundreds of feet of Southwestern Illinois are designated by Lower Ordovician and Cambrian sedi- names used in the Ozark region (see mentary rocks—dolomites, shales, and Figure 2). Oil shows have been re- sandstones—of marine origin. The fold- ported in beds of Prairie du Chien and ing and partial erosion of these older Trempealeau age in tests drilled in strata before the St. Peter sands were West-Central and Southwestern Illinois deposited produced the most marked (see Table 1). No oil shows have been unconformity in the Lower Paleozoic reported in them in the Illinois Basin, succession of Illinois and adjoining but only four tests in the basin have states (see Figure 1). Some of the sub- been drilled into pre-St. Peter strata, surface dolomites and sandstones are and of these none has gone deep enough porous and permeable. Traces of oil to test even all of the Prairie du Chien. have been reported in them in Illinois, The Cambrian formations below the and oil is produced from equivalent Trempealeau are the Franconia, Gales- strata in Texas (Ellenburger limestone), ville, Eau Claire, and Mt. Simon, in Oklahoma and Kansas (Arbuckle or descending order. They have been cor- "Siliceous" lime and the Reagan or related with the Wilberns, Cap Moun- Lamotte or "Basal" sand), and in Ten- tain, and Hickory formations of Texas, nessee (the Knox dolomite). Such con- with the basal portion of the Arbuckle ditions suggest that commercially valu- and the Honey Creek, Cap Mountain, able quantities of oil may occur in the and Reagan formations of Oklahoma, Lower Ordovician and Cambrian for- and the Doe Run, Derby, Davis, Bon- mations in the southern two thirds of neterre, and Lamotte formations of Mis- Illinois, where they constitute an al- souri. They are not known to have been most unexplored geological "layer." penetrated in Southern Illinois, but a Only a few tests have been drilled to well in St. Louis, Missouri, was drilled them and none has been drilled through through them and into the pre-Cam- them in this area. The present discus- brian granite. sion is a preliminary report of a study The Shakopee and Oneota forma- being conducted by the Illinois Geo- tions in Northern Illinois consist large- logical Survey and is based largely on ly of dolomite with some interbedded data from Northern Illinois. thin sandstones. There are subsurface The Northern Illinois correlatives of openings or "crevices" in the dolomite the Ellenburger, Arbuckle, and Knox beds in places. The New Richmond strata are, in descending order, the formation consists chiefly of sandstone Shakopee, New Richmond, and Oneota with lenses and interbeds of dolomite formations of the Prairie du Chien and thin beds of shale. In LaSalle group of Lower Ordovician age and County, in North-Central Illinois, the the Trempealeau formation of Upper permeability of the New Richmond FIGURE 1

Graphic cross-section of Lower Ordovician and Cambrian strata in Northeastern Illinois, based on electric logs and sample studies. . ...

TABLE 1 Oil Shows in Lower Ordovician and Cambrian Formations, Reported by Driller

OIL SHOWS Total Depth Date COUNTY Sec. T.. R.. Operator. Farm and Well No. Formation Depth (feet) (feet) Drilled

Jersey 32-7n-l lw, A. W. Gerson, Knight 1 Jefferson City 1765-70 2235 1939 McDonough.. 33-5n-4w, Currv & Rollestone, Hardy 1 Jordan? 1822? 2306 1930

Monroe 20-2s-9w, E. H. Gorse, Hergenroeder 1 . Jefferson City 1700-12 2248 1909

St. Clair 26-ln-10w, S. G. Lockwood, Dyroff 1. . 2054-61 2904 1924 Gasconade 2300-07 Van Buren (gas) 2320-47 Eminence 2540-47 2580-90 2710-14 2812-28 2836-50 Potosi 2900-04 St. Clair 28-ln-10w, Tarlton & Sklar, Dyroff 1-A Powell 1075-90* 1800 1943

* Reported by scout.

sandstone in outcrops ranges to more which is silty and sandy. In the dolo- than 5,000 millidarcies, and its thick- mite are numerous quartz-lined vugs ness in the subsurface approaches 200 and some large openings as much as 8

feet. Elsewhere it is much thinner. To feet in height. The latter, termed "crev-

the east it either grades laterally into ices" by the drillers, under different dolomite or wedges out so that the conditions make or take great volumes Shakopee overlaps it and lies directly of fluid; they seemingly represent ex- on the Oneota. Oolitic chert and sili- tensive cavern systems that were de- ceous oolites occur in both dolomites veloped after Trempealeau and before and sandstones and serve to distinguish St. Peter time. The thickness of the the Prairie du Chien formations from Trempealeau ranges from to 260 feet overlying and underlying formations. in Northern Illinois; its normal thick- Throughout large areas in Northern ness is approximately 200 feet. Local Illinois Prairie du Chien strata are variations in thickness of the Trem- missing and the St. Peter formation pealeau and the widespread occurrence rests on Cambrian strata. Apparently of "crevices" suggest that an uncon- these areas were upfolded and the formity of some magnitude separates Lower Ordovician and some of the the Trempealeau from the overlying Cambrian strata were stripped away in Prairie du Chien. pre-St. Peter time. In other areas the The Franconia formation comprises Prairie du Chien attains a thickness of glauconitic sandstone, sandy shale, and more than 400 feet, but even in these sandy dolomite. Some of the sandstones areas it is locally thin or absent owing are porous, others are argillaceous or

to pre-St. Peter erosion. Its surface re- dolomitic and "tight." Permeability is sembles sink-hole or karst topography restricted horizontally by cross-bedding like that of the Arbuckle dolomite, and lenticularity, vertically by shale which is its correlative and a prolific partings and interbeds. The thickness producing zone in the Silica and Trapp of the Franconia ranges from less than 3 pools of Kansas.*' The Prairie du 50 to almost 200 feet. Chien group thickens southward, being The Galesville formation consists of between 800 and 900 feet thick in porous sandstone with interbeds of Southwestern Illinois. sandy dolomite. The permeability of The Trempealeau formation, which outcrop samples from Wisconsin ex- consists chiefly of siltstone and sand- ceeds 5000 millidarcies. The average stone (including the Jordan, a highly thickness of the Galesville in Northern permeable sandstone) in Iowa and Wis- Illinois is almost 200 feet. consin, is dominantly dolomite in Il- The Eau Claire formation includes linois. Apparently the sandstones and shales, siltstones, sandstones, and dolo- siltstones of adjoining states grade mites, many of which are glauconitic laterally into the dolomite, some of and fossiliferous. Some of the lower NORTHERN MISSOURI OKLAHOMA TEXAS ILLINOIS

z Black Rock < z Smithville > I Powell o o Cotter Q 3 DC o Shakopee Jefferson City O LI New Richmond Roubidoux tr Oneota Gasconade Arbuckle Ellenburcer a. Van Buren o a. ("Siliceous lime") _l Gunter ss. member

Jordan ss. member Eminence

Trempealeau Potosi

Doe Run zUl z Franconia Derby WlLBERNS < Honey Creek u Davis m Ironton ss. member < Galesville Lion Mt ss member o Cap Mountain Cap Mountain Eau Claire BONNETERRE

Mt Simon Lamotte Reagan Hickory ~~

FIGURE 2

Tentative correlation chart of Lower Ordovician and Cambrian strata Based principally upon: (a) Bridge, Josiah, The Correlation of the Upper Cambrian Sections of Missouri and Texas with

t i f i_ _i. i I i _<«_». Hiimche SectionJCV.MUII inill thenic Uppervyuuci MississippiIVU33I33IUUI Valley:u y U.\j . S. vjcui.Geol. Surveypurvey IProf.iui. Paperup ci 186uu— L,i_, 1936.y (b)luj Bridge, Josiah, Geology of the Eminence and Cardareva Quadrangles: Missouri Bur. Geol. and Mines, Vol. 24, second ser., 1930. (c) Dake, C. L, and Bridge, Josiah, Faunal Correlation of the Ellenburger Limestone of Texas (with an appendix by E. 0. Ulrich): Bull. Geol. Soc. America, Vol. 43, pp. 725-48, 1932.

Eau Claire sandstones possess good proximately 1700 feet to more than porosity and permeability. The Eau 2200 feet in Northern Illinois. Claire averages between 400 and 500 The thickness of all the Lower Or- feet in thickness. dovician and Cambrian strata below the The Mt. Simon formation consists al- St. Peter in the deep well at St. Louis, most entirely of sandstone, some of it Missouri, was reported to be 2230 feet. porous and permeable. Formerly all the The Lower Ordovician and Cambrian sedimentary strata below the Eau Claire formations in Illinois have experienced formation and above the pre-Cambrian a number of periods of structural move- granite were called Mt. Simon in Illi- ment. The most important of these were nois, but on the basis of recent studies (1) in the Ordovician period, after it is now considered that the lower part Shakopee and before St. Peter deposi- of this sequence, consisting of conglom- tion, (2) during the period, eratic and arkosic sandstones and (3) in the post-Mississippian, pre-Penn- sandy shales, prevailingly red in color, sylvanian interval, and (4) in post- is a separate formation and may be Pennsylvanian time. Structural traps equivalent to the Fond du Lac beds of for the accumulation of oil in the for- pre-Cambrian age in Minnesota. The mations below the St. Peter could have thickness of the sedimentary section be- been formed during any or all of these low the Eau Claire ranges from ap- and other periods of folding. There also

10 might be stratigraphic traps in the and Cambrian production may be as dolomites and sandstones below the St. good in the Illinois basin as in Eastern Peter. and Western Illinois, but drilling costs probably are too high to warrant much Whether or not the structure of the exploration there until more is known overlying beds can be used as a guide about the Lower Ordovician and Cam- in exploration for oil in the Lower Or- brian in other parts of Illinois. Depth to dovician and Cambrian formations is the top of the Lower Ordovician is less not now known, nor can it be predicted than 4000 feet throughout most of whether the formations below the St. Western Illinois and along a greater Peter will more probably be productive part of the LaSalle anticlinal belt, but in pools producing from higher forma- in the basin it is as much as or more tions or in areas where the higher for- than 8000 feet. mations produce no oil. The Lower Or- Although the pre-St. Peter sedimen- dovician formations have been reached tary rocks of Central and Southern Illi- on only four producing structures in nois have been so little explored that Illinois; the Cambrian on only one. On the Lower Ordovician and Cambrian the Waterloo-Dupo anticline, the only producing structure tested to the Cam- geological conditions there are little known, it may be inferred that they are brian, an oil show was reported in the Lower Ordovician, and several shows similar to conditions in Northern Illi- nois. If so, there is lack of were reported in both Lower Ordovi- no porous zones and of structural traps, and pos- cian and Cambrian formations in a test sibly stratigraphic traps. Oil shows re- on the flanks of the structure. The ported to occur in these rocks in Illi- greatest thickness of pre-St. Peter nois and the quantity of oil produced strata penetrated on the other three from their equivalents in other states structures that were drilled into the suggest that commercial production Lower Ordovician was only 230 feet, may be obtained from them in Illinois. which is not enough for a real test. All tests of them should be drilled at structural viewpoint there are From a least through the Trempealeau forma- Illinois that appear to be two regions in tion; and to be thorough they should for Lower Ordovician most favorable be drilled into the Mt. Simon forma- prospecting at present. and Cambrian tion. Structurally favorable areas in the Eastern Illinois, from Ford They are (1) eastern and western parts of the state Counties south to Wabash and Iroquois are considered the best possibilities for Western Illinois, from County, and (2) current exploration for Lower Ordo- and Warren Counties south Henderson vician and Cambrian oil pools in Illinois. to Randolph County. Through Eastern Illinois extends the LaSalle anticlinal ACKNOWLEDGEMENTS belt, the most prominent structural fea- The writer is indebted to M. M. Leighton. ture of the state; along it are several A. H. Bell. L. E. Workman, George E. Ekblaw, ''ail A. Bays, and other staff members of well-defined closures, none of which the Illinois Geological Survey, and to Anthony Folger, consulting geologist, for suggestions drilled below the St. Peter have been and helpful criticism of this report. The formation, south of Ford County. permeability analyses of the New Richmond and Galesville sandstones were made by E. P. DuBois, and some of the stratigraphic infor- in There are a number of anticlines mation is based on studies by L. E. Workman, F. E. Tippie, Paul Herbert, Jr., and other Illinois on which the Lower Western members of the Illinois Geological Survey. Ordovician and Cambrian strata merit testing. Some of them are Pennsyl- REFERENCES vanian or later in age, some are pre- 1 Broadhead, G. C, cited in Fenneman, N. M., Geology and Mineral Resources of the St. Mississippian. The fact that Western Louis Quadrangle, U. S. Geol. Surv. Bull. 438, pp. 15-17, 1911. Illinois was structurally high during the 2 Ver Wiebe, Walter A., Exploration for Oil and Devonian periods as well and Gas in Western Kansas during 1940; State Geol. Survey of Kansas Bull. 36, pp. as at later times suggests that there also 82-84. 1941. 3 Testimony at Silica pool folding in Folger, Anthony, may have been pre-St. Peter hearing before Kansas Corporation Commis- "Sink Holes the area. sion, December, 1940, reported as Important Feature in Arbuckle Dolomite." Oil and Gas Journal, vol. 39, No. 31, pp. 21 Possibilities for Lower Ordovician and 97, December 12, 1940.

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