Press Bulletin Series Issued Twice tjuurterlv STATE OF ILLINOIS DEPARTMENT OF REGISTRATION AND EDUCATION A. \I. SHBLTON, Director DIVISION OF THE STATE GEOLOGICAL SURVEY M. M. LEIGHTON, Chief, Vroana no i ILLINOIS PETROLEUM April 17, 1926 CONTENTS PAGE Foreword 1 Oil and gas possibilities in the Sparta area (with map) 2 Oil development in Illinois in 1925 7 FOR E WORD Illinois Petroleum is a new Press Bulletin series which is to be issued by the Illinois State Geological Survey, in order to make the results of in- vestigations bearing on the exploration and recovery of oil and gas in Illi- nois available for the benefit of the petroleum industry of the State at the earliest possible moment. Illinois Petroleum is to appear twice quarterly. Tt will give information on recent oil developments in Illinois, new areas deserving investigation, new horizons worthy of testing, and new technical methods which should help to increase or maintain present production. In the succeeding early numbers, articles will appear regarding the use of the core bit for cable tools, the advisability of testing deeper horizons in certain pa its of Wabash County, and developments in Illinois during the first quar- ter of 1926. In 1905, the production of petroleum in Illinois began to assume an important role. In that same year, the State Legislature established by enactment the State Geological Survey. Its office was organized in the fall of 190."), and by February, 1906, the State Geological Survey had its oil geologist in the field. Ever since that date, the Survey has maintained a close association with the operators and drillers, and by studying the trends of the geologic structure and by identifying and differentiating the oil- hearing horizons, has been able to provide information leading to further development and maintenance of production. In issuing Illinois Petroleum, for the express purpose of promoting the welfare of the oil and gas industry of this State, acknowledgment is cor- dially made in this first number of the line cooperative spirit which the oil He 04 "■ L '< j limestone I Maquoketa i ? t shale Kimmswick f, Plattin limestone St. Peter sandstone Osage and Kinderhook series I Silurian I system Ordovieian system, R. 4 W. ;s represent the elevation of the top of the Herrin (No. 6) coal. Broken contoui ■dmate trend. 6 ILLINOIS PETROLEUM serve equally favorable consideration. If one or both of these structures produce important amounts of oil or gas, then tests should be drilled on the other areas of slightly less promise. Further drilling in the vicinity of the old oil production should yield profitable results if undertaken with the guidance of careful geologic work for the determination of structural and sand conditions. The well being drilled near Sparta at the present time should show what may be expected in further tests. What appears to be the most favorable area for testing for oil or gas outside of the vicinity of the present production of the Sparta region, is the small dome located in sees. 23, 24, 25, and 26, a short distance northeast of Blair in T. 5 S., R. 6 W. (area No. 1 ). This dome is considered favorably because of the very abrupt west dip which can be determined from outcrops along the branch of Little Marys River where it crosses the Sparta-Blair road. According to observations at this point, there is an abrupt dip of at least 25 feet to the west in a distance of about one-eighth of a mile. It is believed that a well located near Little Marys River, a few rods east of the road, would test this area. The area immediately west of Tilden (area No. 2) shows a well defined structure as determined from data on the coal. Although a deep well is now being completed a short distance from this structure, it does not con- demn the area as a possible oil and gas producer, for the elevation of the coal at that point is 40 or 50 feet lower than on the highest part of the structure. A well located near the center of sec. 1 west of Tilden should be a test of its oil and gas possibilities. The other areas which are recommended should be tested only after the conditions in the two most promising areas have been determined. It is likely that tests located in the central parts of these areas would have the preference for testing their possibilities. Horizons to be Tested Obviously, all of the test wells drilled for the purpose of obtaining oil and gas should be carried to the Chester stratum which has given the oil and gas production in the vicinity of Sparta. In addition, it would be advisable to drill at least one test into some of the lower rocks which are possible pro- ducing horizons. As may be seen from the stratigraphie section accom- panying the map there are several of these as follows : The St. Louis lime- stone, the Silurian limestone, and the Kimmswick-Plattin limestone. While it may not be practical to drill deep enough to test the Kimmswick-Plattin, it seems that testing of the others should be undertaken. Drilling previous to the date of this report has indicated that the oc- currence of the present producing sand near Sparta is somewhat irregular. Accordingly, a well could not be considered to have condemned a structure unless it should find this sand present and full of water. Obviously, no production could be expected if only non-porous rocks were found to occur at the producing horizon. PETROLEUM DEVELOPMENTS DURING 1025 7 Cooperation op the [llinois Geological Survey In order to further their own interests, operators in western Illinois should be particularly careful to cooperate with the Illinois Geological Sur- vey by providing very careful information concerning the formations through which they drill. Although many tests have already been drilled in the Sparta area, there is a comparatively small number for which the data have been kept with a sufficient degree of accuracy to obtain the maxi- mum benefits. As a result, information which would probably be worth several thousand dollars to operators intending - to prospect for oil and gas in the Sparta area is not available and may be obtained only from the examination of careful records of several wells which may be drilled in the future. Accordingly, it is urged that the State Geological Survey be given full information regarding all future tests so that the maximum assistance may be provided for further prospecting. PETROLEUM DEVELOPMENTS DURING 1925 By Gail F. Moulton New developments in Illinois during 1925 were fairly satisfactory, for the percentage of dry holes was reasonably low and the average size of the producing. wells was the largest in recent years. The following table shows the results of drilling for the past three years in summary form. Year Complet inns Total initial product ion Dry holes (las Ave. initial production "foil wells Per rent 1923 260 5,014 113 (43.4) 18 33 1924 174 5,568 51 (29.3) 2 45.1 1925 231 10,028 70 (30.3) 6 64.7 The new production developed during the year was of sufficient im- portance to cause a reduction in the rate of production decline, so that the production for 1925 was nearly as great as that for 1924, or almost 8,000,000 barrels. Prospecting proved up about 900 acres of new territory in Wabash County, about 100 acres of new territory in Clark County, 80 acres in Marion County, and some minor additions in other portions of the State. The principal drilling activity continued in Clark and Wabash coun- ties during 1925. In Crawford and Lawrence counties a small amount of drilling was done on edge locations and a few wildcat tests were drilled without satisfactory results. Similar development work was carried on in the minor producing areas in central and western Illinois. Xo important discoveries resulted from this work. 8 ILLINOIS PETROLEUM The greatest activity took place in Wabash County where real boom conditions existed for a time after the discovery of some large wells north of Allendale. Several of the wells had an initial production of more than 500 barrels, and at one time 4 of the wells in the field would flow if allowed to stand. The producing wells drilled here during the last three months of the year average about 150 barrels initial production, and the percentage of dry holes was reasonably low. Wabash County drilling tested the Biehl horizon at a depth of about 1400 feet over a considerable area, but some tests which were located on favorable structures failed to find the Biehl sand and unfortunately were not drilled deep enough to test the several possible oil producing horizons beneath which are the equivalent of the Kirkwood, Tracey, and McClosky sands of Lawrence County. In Clark County, there was considerable activity in the Martinsville deep sand area. Some additional areas were tested, but the principal ac- tivity was in deepening the wells already producing from the Carper sand in the Mississippian black shale at 1400 feet to the Devonian limestone at 1600 feet. Although a considerable amount of water must be handled with the deeper oil, no extra casing is needed so that the additional cost is com- paratively small. The James Oil Company opened a new pool in Marion County about two miles east of the older production. Four producing wells have been ob- tained which find their production in sands in the Pennsylvanian system. None of these wells is deep enough to test the horizons from which most of the production in the Sandoval, Junction City, and Centralia pools is ob- tained. Although the geology has not been worked out in detail yet, it seems possible that the accumulation may be caused by a small fault. Since faults are known to occur in adjacent areas, and if this accumulation has been caused by such a structure, much additional prospecting should be done in the vicinity. A well drilled in McDonough County, east of Plymouth, on Gin Ridge obtained 10 to 15 barrels of heavy black oil at a depth of 650 feet from the Hoing sand horizon of the Plymouth field. Further prospecting in ad- jacent areas is in progress and will help to determine the extent of the Hoing sand. Drilling in other parts of the State failed to yield any results of par- 1 icular importance.