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Character of the Oil
Table A—Results of Distillation of Oil from Eldorado Field, Butler County, Kansas. (Distillation by Bureau of Mines in Hempel flask; Ernest W. Dean, chemist. Samples collected in April, 1918, distilled in July, 1918.)
| 660-Foot Sand | Stapleton Oil Zone | Sluss Sand | Smock Sand | |||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | 11 | ||||||||||||||||||||||||||||||||||
| Field No. | 2 | 4 | 1 | 3 | 5 | 6 | 7 | 12 | 9 | 10 | 11 | |||||||||||||||||||||||||||||||||
| Laboratory No. | .00260 | .00258 | .00264 | .00259 | .00257 | .00261 | .00263 | .00262 | .00256 | .00254 | .00255 | |||||||||||||||||||||||||||||||||
| Size of sample | 1 pint | 1 pint | 1 pint | 1 pint | 1 pint | 1 pint | 1 pint | 1 pint | 1 pint | 1 pint | 1 pint | |||||||||||||||||||||||||||||||||
| Portion distilled (cubic centimeters) |
200 | 200 | 200 | 200 | 200 | 200 | 200 | 200 | 200 | 200 | 200 | |||||||||||||||||||||||||||||||||
| Gravity at 15 (°C) Specific |
0.851 | 0.846 | 0.854 | 0.845 | 0.848 | 0.866 | 0.863 | 0.854 | 0.860 | 0.834 | 0.845 | |||||||||||||||||||||||||||||||||
| Gravity at 15 (°C) Baume (') |
34.5 | 35.5 | 33.9 | 35.7 | 35.1 | 31.7 | 32.2 | 33.9 | 32.8 | 37.9 | 35.7 | |||||||||||||||||||||||||||||||||
| Sulphur | 0.17 | 0.15 | 0.13 | 0.13 | 0.18 | 0.18 | 0.12 | 0.13 | 0.18 | 0.17 | 0.17 | |||||||||||||||||||||||||||||||||
| Wax | Some | Some | Appreciable amount |
Some | Small amount |
Some | Appreciable amount |
Small amount |
Appreciable amount |
Small amount |
||||||||||||||||||||||||||||||||||
| Distillation: First drop (°C) |
24 | 22 | 28 | 24 | 27 | 28 | 30 | 25 | 32 | 24 | 26 | |||||||||||||||||||||||||||||||||
| Pressure (millimeters) | Air: 740. | Vacuum 40 |
Air: 740. | Vacuum 40 |
Air: 740. | Vacuum 40 |
Air: 740. | Vacuum 40 |
Air: 741. | Vacuum 40 |
Air: 737. | Vacuum 40 |
Air: 738. | Vacuum 40 |
Air: 744. | Vacuum 40 |
Air: 744. | Vacuum 40 |
Air: 744. | Vacuum 40 |
Air: 740. | Vacuum 40 |
||||||||||||||||||||||
| Fraction (per cent) |
Total (per cent) |
Specific gravity of fractions |
Total (per cent) |
Fraction (per cent) |
Total (per cent) |
Specific gravity of fractions |
Total (per cent) |
Fraction (per cent) |
Total (per cent) |
Specific gravity of fractions |
Total (per cent) |
Fraction (per cent) |
Total (per cent) |
Specific gravity of fractions |
Total (per cent) |
Fraction (per cent) |
Total (per cent) |
Specific gravity of fractions |
Total (per cent) |
Fraction (per cent) |
Total (per cent) |
Specific gravity of fractions |
Total (per cent) |
Fraction (per cent) |
Total (per cent) |
Specific gravity of fractions |
Total (per cent) |
Fraction (per cent) |
Total (per cent) |
Specific gravity of fractions |
Total (per cent) |
Fraction (per cent) |
Total (per cent) |
Specific gravity of fractions |
Total (per cent) |
Fraction (per cent) |
Total (per cent) |
Specific gravity of fractions |
Total (per cent) |
Fraction (per cent) |
Total (per cent) |
Specific gravity of fractions |
Total (per cent) |
|
| Fractions (°C): | ||||||||||||||||||||||||||||||||||||||||||||
| Up to 50 | 3.0 | 3.0 | .649 | 3.4 | 3.4 | .652 | ||||||||||||||||||||||||||||||||||||||
| 50 to 75 | 3.0 | 3.0 | .660 | 3.6 | 3.6 | .662 | 3.1 | 3.1 | .661 | 2.5 | 5.5 | 668 | 3.2 | 6.6 | .675 | |||||||||||||||||||||||||||||
| 75 to 100 | 5.9 | 5.9 | .697 | 4.8 | 7.8 | .716 | 5.6 | 5.6 | .700 | 4.7 | 8.3 | .715 | 4.7 | 7.8 | .717 | 3.9 | 3.9 | .702 | 3.2 | 3.2 | .696 | 5.9 | 5.9 | .692 | 3.0 | 3.0 | .705 | 5.2 | 0.7 | .723 | 5.6 | 12.2 | .727 | |||||||||||
| 100 to 125 | 6.7 | 12.6 | .738 | 6.2 | 14.0 | .742 | 5.4 | 11.0 | .739 | 7.3 | 15.6 | .744 | 5.9 | 13.7 | .743 | 4.2 | 8.1 | .738 | 3.8 | 7.0 | .735 | 6.6 | 12.5 | .740 | 4.1 | 7.1 | .740 | 5.1 | 15.8 | .746 | 5.5 | 17.7 | .749 | |||||||||||
| 125 to 150 | 6.7 | 19.3 | .759 | 6.0 | 20.0 | .760 | 6.8 | 17.8 | .755 | 7.4 | 23.0 | .762 | 6.6 | 20.3 | .764 | 6.7 | 14.8 | .761 | 6.1 | 13.1 | .753 | 6.2 | 18.7 | .758 | 6.0 | 13.1 | .758 | 5.6 | 21.4 | .763 | 5.7 | 23.4 | .766 | |||||||||||
| 150 to 175 | 6.4 | 25.7 | .775 | 2.5 | 6.8 | 26.8 | .779 | 1.0 | 6.9 | 24.7 | .772 | 2.0 | 6.6 | 29.6 | .782 | 6.5 | 26.8 | .778 | 6.7 | 21.5 | .780 | 6.8 | 19.9 | .775 | 2.0 | 6.4 | 25.1 | .778 | 1.0 | 6.6 | 19.7 | .776 | 5.5 | 26.9 | .783 | 4.0 | 6.0 | 29.4 | .787 | 1.5 | ||||
| 175 to 200 | 5.9 | 31.6 | .795 | 8.5 | 6.2 | 33.0 | .797 | l.5 | 5.6 | 30.3 | .794 | 4.0 | 5.9 | 35.5 | .801 | 1.0 | 6.0 | 32.8 | .797 | 3.5 | 5.7 | 27.2 | .801 | 5.0 | 6.0 | 25.9 | .794 | 6.0 | 5.9 | 31.0 | .790 | 2.5 | 6.5 | 26.2 | .798 | 1.0 | 5.0 | 31.9 | .801 | 6.0 | 5.4 | 34.8 | .805 | 5.0 |
| 200 to 225 | 6.3 | 37.9 | .812 | 15.0 | 6.3 | 39.3 | .815 | 3.0 | 6.6 | 36.9 | .812 | 10.0 | 5.9 | 41.4 | .817 | 4.5 | 6.1 | 38.0 | .813 | 8.5 | 6.5 | 33.7 | .818 | 7.5 | 6.1 | 32.0 | .815 | 15.0 | 6.3 | 37.3 | .813 | 7.5 | 6.4 | 32.6 | .817 | 5.5 | 5.3 | 37.2 | .817 | 10.5 | 4.9 | 39.7 | .821 | 10.0 |
| 225 to 250 | 7.5 | 45.4 | .827 | 20.0 | 6.5 | 45.8 | .843 | 7.5 | 6.6 | 43.5 | .828 | 16.0 | 6.5 | 47.9 | .833 | 7.0 | 6.6 | 45.5 | .830 | 12.5 | 7.8 | 41.5 | .832 | 13.0 | 7.5 | 39.5 | .830 | 20.0 | 6.4 | 43.7 | .829 | 14.5 | 7.5 | 40.1 | .831 | 12.5 | 5.8 | 43.0 | .832 | 15.5 | 6.4 | 46.1 | .832 | 15.0 |
| 250 to 275 | 6.0 | 51.4 | .843 | 25.0 | 9.6 | 61.7 | .855 | 14.0 | 6.7 | 50.2 | .841 | 21.0 | 6.0 | 60.4 | .858 | 12.0 | 6.1 | 51.6 | .842 | 16.5 | 7.0 | 48.5 | .843 | 18.0 | 5.5 | 45.0 | .842 | 25.0 | 6.6 | 50.3 | .841 | 18.5 | 6.9 | 47.0 | .847 | 18.0 | 5.1 | 48.1 | .845 | 20.5 | 5.3 | 51.4 | .848 | 20.5 |
| 275 to 200 | 31.0 | 20.0 | 6.6 | 56.8 | .857 | 26.0 | 19.5 | 6.5 | 58.1 | .856 | 22.5 | 6.6 | 55.1 | .856 | 24.0 | 31.0 | 7.6 | 57.9 | .853 | 25 5 | 7.9 | 54.9 | .856 | 24.0 | 28.5 | 27.5 | ||||||||||||||||||
| 1. Empire Gas and Fuel Company's W. C. and C. 1). Wilson farm well No. 2, sec. 8, T. 25 S., R. 5 E. Sample obtained directly from flow line. 2. Empire Gas and Fuel Company's Hegberg farm well No. 49, sec. 28, T. 25 S., R. 5 E. Sample obtained directly from flow line. 3. Theta Oil Company's F. W. Robison farm well No. 13, sec. 3, T. 25 S., R. 5 E. Sample obtained directly from flow line. 4. Empire Gas and Fuel Company's W. C. and C. D. Wilson farm well No. 1. Sample obtained directly from flow line. 5. Empire Gas and Fuel CorDpany's Hegberg farm well No. 38, sec. 28, T. 25 S., R. 5 E. Sample obtained directly from flow line. 6. Gypsy Oil Company's Shurrv~ay farm well No. 13, sec. 11, T. 26 S., R. 4 E. Sample obtained directly from flow line while producing at rate of about 18,000 barrels per day. 7. Ramsey Petroleum Company's Harmon farm well No. 5, sec. 24, T. 26 S., R. 4 E. Sample obtained directly from flow line. 8. National City Oil Company's Beaumont well No. 2, sec. 3, T. 26 S., R. 5 E. Sample obtained directly from flow line. 9. Empire Gas and Fuel Company's Boyer farm well No. 4, sec. 8, T. 26 S., R. 5 E. Sample obtained directly from flow line. 10. Bole and Skelly's W. U. Sluss faym Nk ell No. 1, sec. 26, T. 26 S., R. 5 E. Sample obtained directly from flow line. 11, J. S. Cosden's SXnock farm well No. 1, sec. 2, T. 27 S., R. 5 E. Sample obtaineu directly from flow line. |
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The oil produced in the Eldorado field has a specific gravity which ranges in general from 0.870 to 0.833 (31.0° to 38.0° B.). Its distillation fractions are indicated in table A. A comparison of the analyses of oil from the 660-foot sand and Stapleton pay rocks shows them to be practically of the same grade. If any real difference exists, it would seem that the shallower oil is somewhat lighter. No distinction, however, is made in marketing the oil.
No samples were obtained of the oil from the Boyer and Stokes "sand."
The oil of the Smock-Sluss district is of slightly higher rank than that of the main Eldorado field. This is indicated in the analyses of the table, where the gravities of two samples are given as .834 (37.9° B.) and .845 (35.7° B.), respectively, or about 2 to 3 degrees Baume higher than that of the oil from the main field. It differs also in its content of dissolved natural gas, of which in the spring of 1918 there was sufficient caught at the casing head to supply the gas engines used in pumping the wells.
The variety and percentage of refinery products derived from the Eldorado oil by skimming plants (so called because they distill off only the higher fractions of the crude oil) is indicated in the following table, the figures for which were derived by lumping the quantities reported by several refineries obtaining all their crude oil from the Eldorado district.
| Percentages of refinery products derived from Eldorado crude oil during the period, January 1 to November 30, 1919. Data obtained from Bureau of Mines. | |||||
|---|---|---|---|---|---|
| Gasoline | Kerosene | Gas and fuel oils | Distillates | Losses | |
| 27.2 | 11.3 | 58.0 | 1.2 | 2.3 | |
Expulsive Force in Gusher Wells
In considering the Eldorado oil it seems fitting in this place to discuss briefly the forces which expel it from the flowing wells, especially from the large-sized wells. As noted on pages 21 and 103, there is comparatively very little gas accompanying the oil. So small is the amount that in the Gypsy Oil Company's Shumway well No. 5 (center location west side of SW NE, sec. 11, T. 26 S., R. 4 E., approximately 15,000 barrels a day) the column of oil issuing from the six-inch casing rose only about 6 feet before falling back to the ground. This lack of gushing is well indicated in plate V (B and C). A slightly different but equally illustrative intsance, as reported to the writer by Mr. J. C. Jordan, treasurer of the company, was the Union Oil Company of Wichita's Denny well No. 18 (southwest corner location, SE, sec. 12, T. 26 S., R. 4 E.), cited on p. 103, which when drilled in did not actually flow of its own accord, but required the agitation of a swab. With the swab working at a depth of less than 600 feet, the well at one time produced as high as 400 barrels an hour. After such agitation with the swab the well would continue to flow for several hours, but at a decreasing rate. Once shortly after the well was brought in, and with the tools in the hole, and the swab hanging idle in the hole, the well flowed 300 barrels per hour for four hours after the swabbing ceased. It is to be noted that, a production of 300 barrels per hour would be equivalent to 7,200 barrels per day.
From these instances it would appear that the small amounts of dissolved gases have but little effect in forcing the oil to the surface, except perhaps to a very small degree. With the dissolved gases apparently impotent, the pressure under which the oil and salt water exist in these subterranean reservoirs must be appealed to as the prime cause in forcing the oil to the surface. The cause for this pressure is not altogether clear, but at least is in part simple rock pressure, or the pressure produced by the weight of overlying rock under which the fluid is confined. If this were the only cause of the pressure, the salt water, if tapped by a well in the same reservoir, would flow equally as fast as the oil. While such may be the case, the writer has no definite information concerning it.
Character of the Natural Gas
Table B—Composition of Natural Gas from the Eldorado Field.
| Location Section, township south, and range east. |
Well | "Sand" | Depth | Constituents | Heating value (B.t.u.) |
Analyst | Where published | Remarks | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Methane, marsh gas, (CH4) percent |
Ethane (C2H6) percent |
Carbon dioxide (CO2) percent |
Oxygen (O) percent |
Residue, principally nitrogen (N) percent |
Higher hydro- carbons percent |
Helium percent |
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| 33-2 | Stokes No. 51 | 900-foot | 851-858 | 54.46 | 4.31 | 0.24 | 40.99 | 600 | Not published | Analysis made by Empire Gas & Fuel Co. | ||||
| 17-26-5 | Koogler No. 1 | 900-foot | 827-840 | 56.38 | 4.34 | 39.65 | 2.09 | *1.17 | 674 | R. O. Neal | Not published | Analysis made by Empire Gas & Fuel Co. | ||
| 17-26-5 | Gussman No. 1 | 900-foot | 885-892 | 60.68 | 3.22 | 0.19 | 35.95 | *1.24 | 642 | R. O. Neal | Not published | Analysis made by Empire Gas & Fuel Co. | ||
| 17-26-5 | Nichelger No. 1 | 900-foot | 875-887 | 54.78 | 7.19 | 0.24 | 37.40 | 0.41 | *0.91 | 663 | E. E. Lydex | Not published | Analysis made by Empire Gas & Fuel Co. | |
| 17-26-5 | Empire No. 7 | 900-foot | 868-880 | 55.24 | 7.12 | 0.12 | 37.52 | 657 | E. E. Lyder | Not published | Analysis made by Empire Gas & Fuel Co. | |||
| 21-25-5 | Chesney No. 2 | 1, 275-foot | 1,218-1,228 | 58.42 | 9.15 | 0.05 | 0.10 | 32.28 | 722 | E. E. Lyder | Not published | Analysis made by Empire Gas & Fuel Co. | ||
| 21-25-5 | Chesney No. 5 | 1,275-foot | 1,220-1,229 | 59.53 | 6.44 | 0.19 | 0.24 | 33.60 | 691 | E. E. Lyder | Not published | Analysis made by Empire Gas & Fuel Co. | ||
| 21-25-5 | Chesney No. 13 | 1,275-foot | 1,230-1,240 | 62.62 | 5.00 | 0.53 | 0.54 | 31.15 | 0.12 | 710 | U. E. Lyder | Not published | Analysis made by Empire Gas ∧ Fuel Co. | |
| 36-25-3 | Adsit No. 3 | 1,475-foot | 1,482-1,493 | 31.36 | 12.78 | 0.12 | 0.12 | 55.64 | 524 | D. B. Dow | Not published | Analysis made by Empire Gas & Fuel Co. | ||
| 31-25-5 | Robinson No. 23 | 1,475-foot | 1,505-1,510 | 48.79 | 21.59 | 0.21 | 29.41 | 845 | R. O. Neal | Not published | Analysis made by Empire Gas & Fuel Co. | |||
| 12-26-5 | Enyart No. 2 | 1,475-foot | 1,440-1,465 | 51.55 | 12.38 | 1.36 | 34.50 | 715 | D. B. Dow | Not published | Analysis made by Empire Gas & Fuel Co. | |||
| 900-foot | 1.20 | U. S. Geol. Survey Prof. Paper 121 | Average of 19 samples. | |||||||||||
| 1,200-foot | 1.01 | U. S. Geol. Survey Prof. Paper 121 | Average of 13 samples. | |||||||||||
| *Included in the residue. Determination made separately by the Bureau of Mines, and published in United States Geological Survey Professional Paper 121. | ||||||||||||||
Table C—Composition of Natural Gas from Various Midcontinent Fields. Given for comparison with natural gas from the Eldorado field.
| State and District | Collected from | Constituents | Helium percent |
Heating value (B.t.u.) |
Analyst | Where published | Remarks | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Methane, marsh gas, (CH4) percent |
Ethane (C2H6) percent |
Carbon dioxide (CO2) percent |
Oxygen (O) percent |
Residue, principally nitrogen (N) percent |
Other constituents percent |
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| Kansas: | ||||||||||||||
 |
Butler county: | |||||||||||||
|
|
North Augusta field | Representative analyses | 63.92 | 5.67 | 0.07 | 0.19 | 29.96 | Higher hydrocarbons, 0.19 | 1.09 | 719 | H.C. Allen | U. S. Geol. Survey Prof. Paper 121 | Depth, 1,200 to 1,400 feet. The helium is included in the residue and was determined separately. |
|
|
North Augusta field | 50.22 | 21.32 | 0.31 | 28.15 | Higher hydrocarbons, — | 853 | ||||||
|
|
South Augusta field | Representative analyses | 63.32 | 13.45 | 0.32 | 0.12 | 22.63 | Higher hydrocarbons, 0.13 | 0.43 | 844 | H. C. Allen | U. S. Geol. Survey Prof. Paper 121 | Depth, 1,200 to 1.500 feet. Principal gas supply of the Augusta field. The helium is included in the residue and was determined separately. |
|
|
South Augusta field | 76.48 | 12 60 | 0.21 | 10.26 | Higher hydrocarbons, 0.44 | 961 | ||||||
|
|
South Augusta field | Moyle well No. 7 | 2.13 | H. C. Allen | U. S. Geol. Survey Prof. Paper 121 | Depth about 550 feet. No commercial production. | |||||||
|
Montgomery county: | |||||||||||||
|
|
Caney | Well east of Caney; Caney Gas & Mining Co. | 92.40 | 0.81 | 0.15 | 6.46 | C2H2—0.10 | 0.08 | H. P. Cady and D. F. McFarland | Am. Chem. Sec. Jour., vol. 29, p. 1530 | Depth, 1,550 feet. | ||
| Oklahoma: | ||||||||||||||
|
|
Glenpool | Gas from oil wells | 49.1 | 44.1 | 6.1 | N—0.70 | 1,271 | G. A. Burrell | Bur. Mines Bull. 42, 1913 | ||||
|
|
Pearson | Gas at 900 feet | 51.91 | 1.12 | 0.21 | 46.86 | 0.23 to 0.71 | 520 | U. S. Geol. Sur. Prof. Paper 121 | The helium is included in the residue and was determined separately. The percentage given represents the range in twelve analyses. | |||
| Texas: | ||||||||||||||
|
|
Petrolia | Beatty well No. 1 | 52.7 | 9.3 | 0.2 | N—37.8 | 0.93 | 734 | G.A. Burrell | U. S. Geol. Survey Bull. 629, p. 41 | Analysis furnished by Lone Star Gas Co. | ||
|
|
Petrolia | U.S. Geol. Survey Prof. Paper 121 | General average for field. | ||||||||||
|
|
Mexia-Groesbeck | Mexia Oil and Gas Co., Adamson well | 98.4 | 0.6 | N—1.0 | 1,047 | G. A. Burrell | U. S. Geol. Survey Bull. 629, p. 102 | |||||
Heating Value
The natural gas of the Eldorado field is essentially a mixture of the two gases—methane, or marsh gas (CH4), and ethane (C2H6)—of which the methane is present in much the larger quantity. With these are associated as adulterants other noninflammable gases, which decrease the heating ability of the natural gas, in which lies its principal value.
The heating value of natural gas from the Eldorado field is low in comparison to the natural gas of most fields, its average heating value being about 675 B. t. u. per cubic foot, whereas the average for natural gas in the United States is probably above 900 B. t. u. Many natural gases produce more that 1,200 B. t. u. per cubic foot. This relation may be more specifically noted by comparing the heating values given in the analyses of Eldorado gas in table B and those of other fields in table C.
The cause of the low heating value of Eldorado gas is to be found in its high content of noncombustibles, principally nitrogen, which in many analyses is given as "residue." The residue in the Eldorado gases averages about 35 per cent of the total weight of the gas. This high content of residue is coincident with a highly interesting feature of the Eldorado gas—its content of helium, brought out during the investigations instigated by the World War.
Helium Content
Helium is present in natural gas only in small quantities, generally less than 0.3 per cent, and in fields which have adequate supplies for commercial extraction the percentage is only about 1 per cent. The presence of helium in the noninflammable constituent of Eldorado gas was first brought out by the intensive search during the World War for a non-burning balloon gas, which would not only nullify enemy incendiary bullets in balloon warfare, but would also prove safe in lightning and ignition in case of accident. Although helium was discovered in natural gas as far back as 1905, by Professors Cady and McFarland, of the University of Kansas, its possible value other than as a scientific curiosity was not considered until the necessities of war brought it to the fore. Under the war impetus it was being produced (not in the Eldorado field) on a commercial scale, but failed to reach the battle front prior to the cessation of hostilities.
The geological results of the war investigations have been ably presented by G. S. Rogers, of the United States Geological Survey, in a paper (Rogers, 1920) entitled, "Helium-bearing natural gas." A brief summary of Rogers' conclusions concerning the occurrence of helium in natural gas is as follows:
- The Midcontinent region of the United States contains the largest known accumulations of helium-bearing gas.
- Helium in noteworthy quantities occurs only in those natural gases which have a high nitrogen content (10 to 85 per cent N.).
- The percentage of helium in a natural gas seems to depend on the percentage of nitrogen in a gas, though there is no direct proportion between the two, the ratio varying greatly in different gases.
- Gases rich in helium do not occur at depths greater than about 1,600 feet.
- In fields of two or more gas sands, the shallowest is in most localities the richest.
The Eldorado field was found to contain the richest helium-bearing gas being produced on a commercial scale, but other considerations decided against the placing here of the first government helium-extracting plant.
The helium content of Eldorado gas was found in 33 samples to range from 0.48 to 1.70 per cent, with a general average of 1.12. The helium content of the 900-foot-sand gas averages 1.20 per cent (19 samples), and of the 1,125-foot, 1,200-foot and 1,275-foot groups of sands, 1.01 per cent (13 samples). No samples of the 1,475-foot sand were examined for helium.
Rogers has assumed the average helium content of the Eldorado gas to be 1.12 per cent, but this probably did not include the production from the 1,475-foot sand, of which no analyses were made. It, therefore, seems to the writer that 1.12 is too high as an average for all the gas produced; 1.0 per cent probably is more nearly correct. Assuming 1.0 per cent as the average, and assuming also that the total production of the field is one-third more than that indicated in figure 8, the total amount of helium that could have been obtained in the Eldorado field during the early months of 1918 was about 96,875 cubic feet daily.
In comparison with the near-by Augusta field, the Eldorado gas in general carries a much higher percentage of helium, even though one very shallow and unproductive sand of the Augusta field contains a gas with a helium content ranging as high as 2.13 per cent. The gas from the other producing sands has a helium content ranging from 0.16 to 1.14. The bulk of the production during 1918, which came from the south Augusta field, had an average helium content of only 0.43 per cent.
The Petrolia field, in Clay county, Texas, is the only other large gas field which is known to contain large quantities of helium. Rogers gives 0.93 per cent as the general average helium content for the field. The Petrolia gas was the source of the helium which was being produced for balloon warfare at the time the World War hostilities ceased.
Water Problem
General Considerations
Salt water is almost invariably present in oil and gas fields, and where it occurs in large quantities it is a very serious menace to their successful operation and one of the worst enemies of oil and gas operators. Salt water has caused not only the abandonment of single wells and individual leases, but probably also of entire fields long before the normal quantity of oil and gas present had been extracted. Its destructive action is brought about by encroaching on the oil and gas in the pay sands and entering the wells along with the oil, thereby decreasing the flow of the oil, and entailing increased expense not only for raising it to the surface but also for later separating it from the oil. In some instances it completely "drowns" the oil in otherwise good producing wells. In entering the well in company with the oil it often produces an emulsion of oil and water which is practically worthless until the two are separated by special processes, such as are described on pages 183-185, which further increase the cost, of production. Salt water from a water sand may invade another sand which is oil-bearing, through failure to mud, plug or properly case off the sand from which it comes, or through improperly set casing. In places, too, it corrodes the casing, causing leaks. Some of these water troubles are due to negligence of drillers and operators, and for these the remedy is easily determined; but even where not due to negligence, most of the water troubles can be diagnosed and can be remedied by the application of progressive engineering methods. It must not be presumed that the water menace can be eliminated, but it can be expected that methods will be devised for successfully and economically combating the harm produced by salt water. The abilities of engineers, physicists and geologists are directed to increasing the oil extraction, both rate and total quantity, and the lowering of the cost of oil production. Notable contributions to the solution and the remedy of the water problem from a scientific point of view have been made by numerous writers (McCoy and others, 1919; Neal, 1919; Rogers, 1917). At the time when the field work for this report was in progress the water menace in the Eldorado field was not of paramount interest, but since then it has become increasingly important. The information here presented does not include remedies for the problem, but brings attention to helpful means for determining the location of water trouble, which in the Eldorado field is confined mainly to the Stapleton zone.
In any specific water problem the first steps is to locate the trouble, which invariably resolves itself into determining the source of the water. Does it come from rocks below the oil pay, from within the oil sand, or from sands above the oil-bearing zone, or is it a combination of water from two or more of these sources? Physical means may at times locate the source of the water, as by the use of plugs, drilling tools, colored dyes, etc.; but when these fail, resort may be had to chemical analyses. Rogers was probably the first to publish on the subject of oil-field waters (Rogers, 1917). His results referred to the California fields, in which he showed that the waters from the various sands possessed individual chemical properties, and that from the analysis of a water it was possible to determine rather closely the sand from which it came. This is of great practical use, as in knowing the source of the water it can generally be determined whether faulty casing, unplugged sands, or too deep drilling, etc., is the cause of the water trouble. When the cause of the trouble is ascertained it usually is an easy matter for the engineer and operator to devise methods for its remedy.
Eldorado Waters
Neal pointed out that in the Eldorado field a very marked difference existed between the water in the Stapleton zone and that from above (Neal, 1919). This is clearly brought out in the analyses in the accompanying table (table D), which were very generously supplied by the Empire Gas and Fuel Company. For convenience of discussion, those waters occurring in the Stapleton zone are termed "bottom waters" and those in the higher sands "top waters." Nos. 1 to 4 in table D are bottom waters; 5, 6, 7 and 8 are top waters; and in No. 9 a contaminated water is given as an example of multiple water trouble.
The properties as given in the table accord with the terminology introduced by Palmer (1911), and are determined by translating the physical weights of the constituents into their relative chemical reactive values on a percentage basis, and then by balancing the alkalies with the strong acids to form primary salinity, following which the remainder of the strong acids are balanced with the alkaline earths to form secondary salinity, and finally the remainder of the alkaline earths are balanced with the weak acids to form secondary alkalinity. The differences between the top and bottom waters are to be noted. The chloride salinity of the top waters is very close to 100 per cent, whereas in the bottom waters it averages about 93 per cent; in the top waters there is practically no sulphate salinity, whereas in the bottom waters it averages about 5 per cent. Probably the greatest difference between the top and bottom waters, and a difference which presumably is most readily determined, is the concentration of the dissolved salts. In the bottom waters this concentration, expressed in parts per million, ranges between 20,000 and 30,000, whereas in the top waters it is 6 to 8 times greater, ranging between 165,000 to 195,000.
These differences for the waters of the Augusta field, which are closely similar to those at Eldorado, are summarized by Neal, who states:
"The chief distinction between the top and bottom waters is the percentage of total solids. The content of solids in the top waters averages four or five times as great as that of the bottom waters. The difference in the chloride salinity between top and bottom waters is a reliable index to use in differentiating the various waters. The distinctive character of the waters as regards sulphate content can be used in classifying top and bottom waters."
Although chemical analyses are of great assistance in locating water troubles, their full value cannot be derived until interpreted by one who understands both the geology and chemistry of the specific problem. In this connection, the accuracy, trustworthiness and detail of a drilling log is of inestimable value. The abandonment of wells may often depend on the presence of even a thin shale or limestone break in the sand, which may determine whether or not the water can be effectively cemented or plugged off. The knowledge of such details will often also indicate, prior to testing, the proper length of the plug which should be inserted. This all points to the need of collecting and preserving samples of the drill cuttings every few feet while drilling into the pay sand, and of making accurate steel-line measurements thereto.
Table D—Analyses Showing Properties and Composition of Water in Eldorado Field.
| Name of well | Bottom waters | Average of bottom waters |
Top waters | Average of top waters |
Contaminated waters |
||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Stapleton No. 1 |
Stokes No. 7 |
Shriver No. 3 |
Kirkpatrick No. 39 |
Batman No. 10 |
Batman No. 10 |
Cardey No. 3 |
Hegberg No. 5 |
Cardey No. 5 |
|||
| Sec., twp., and range | 29-25-5 | 28-25-5 | 14-26-4 | 32-25-5 | 8-26-5 | 8-26-5 | 11-26-4 | 28-25-5 | 11-26-4 | ||
| Depth of sand in feet | 2,465-2,500 | 2,463--2,469 | 2,333 | 2,465 -2.477 | 1,700 | 2,000 | 2,000 | 1,696 | |||
| Properties: | % | % | % | % | % | % | % | % | % | % | % |
| Primary salinity | 82.85 | 84.10 | 80.13 | 79.04 | 81.53 | 90.70 | 95.52 | 80.84 | 80.48 | 86.89 | 78.51 |
| Secondary salinity | 14.85 | 13.62 | 17.20 | 20.05 | 16.43 | 9.17 | 4.42 | 19.09 | 19.48 | 13.04 | 20.97 |
| Secondary alkalinity | 2.30 | 2,28 | 2.68 | .90 | 2.04 | .10 | .06 | .07 | .04 | .07 | .52 |
| Chloride salinity | 94.42 | 94.30 | 91.00 | 92.35 | 93.02 | 99.92 | 99.85 | 99.93 | 99.96 | 99.91 | 99.22 |
| Sulphate salinity | 3.28 | 3.43 | 6.30 | 6.75 | 5.19 | .09 | None. | None. | .09 | .26 | |
| Composition | ppm | ppm | ppm | ppm | ppm | ppm | ppm | ppm | ppm | ppm | ppm |
| Sodium and potassium | 7,216 | 7,590 | 9,318 | 8,160 | 8,071 | 61,560 | 63,033 | 60,994 | 60,786 | 61,593 | 33,252 |
| Iron | 34 | 42 | Trace | 38 | 45 | 170 | 13 | 18 | 61 | 116 | |
| Calcium | 820 | 825 | 1,360 | 1,320 | 1,079 | 2,090 | 1,552 | 8,574 | 8,890 | 5,277 | 2,802 |
| Magnesium | 315 | 257 | 377 | 374 | 331 | 2,560 | 647 | 3,284 | 3,200 | 2,423 | 37,98 |
| Sulphate | 508 | 556 | 1,310 | 1,260 | 908 | 101 | 101 | 198 | |||
| Chloride | 12,896 | 13,312 | 16,640 | 14,976 | 14,456 | 106,080 | 101,920 | 118,560 | 118,560 | 111,280 | 66,960 |
| Bicarbonate | 382 | 388 | 587 | 177 | 383 | 83 | 68 | 88 | 63 | 75 | 392 |
| Total solids | 22,137 | 22,962 | 29,624 | 26,267 | 25,266 | 172,418 | 167,491 | 191,502 | 121,517 | 180,810 | 107,518 |
Technological Features
Outlining of Desirable Acreages
Inasmuch as technological features are very subordinate to the main purpose of this report, they will receive but very brief treatment. The acreage which a modern and fully equipped company desires to lease is determined through the services of geologists who outline those areas which are geologically favorable to the accumulation of oil, where this can be done through field studies. In some localities field studies are impossible, but nevertheless here also the geologist, through his knowledge of developed fields in similar regions, is of great assistance in outlining the probable favorable acreage.
Where field studies are undertaken, the principal object is usually the making of a geologic structure map, which is generally based either on dip observations or on determined elevations of the outcropping key rocks. The structure map should show the location and extent of the anticlines, domes, synclines, and undeformed areas. From these advance investigations the structurally more favorable acreage is outlined as the more desirable. As described on page 10, the Empire Gas and Fuel Company by this method located 34 square miles of territory as the most promising for the development of oil in the Eldorado field (not including the Wilson and Robinson domes). Of these 34 square miles but 7 have since been proven barren of oil, and but 31/2 square miles outside of the 34 have been found to contain oil.
Leasing
After the desirable acreage is outlined, agents who specialize in land work obtain leases on the tracts by purchase, either from the fee landowners or from agents who have previously obtained leases. A typical lease form in use in the Kansas oil and gas fields is as follows (Moore and Haynes, 1917, p. 358, 359):
THIS INDENTURE, Made and entered into the ______ day of ______ A. D. 19___, by and between ______ of ______, state of ______, hereinafter called the lessor (whether one or more), of the one part, and ______of ______, I hereinafter called the lessee (whether one or more), of the other part.
WITNESSETH, That the lessor, for and in consideration of the sum of ______ dollars, cash in hand, paid by the lessee, the receipt of which is hereby acknowledged, and of the covenants and agreements hereinafter contained, on the part of the lessee to be paid, kept and performed, has granted, demised, leased and let, and by these presents does grant, demise, lease and let unto the lessee, his heirs, executors, administrators, successors or assigns, for the sole and only purpose of mining and operating for ail and gas, and of laying pipe lines and building tanks, power stations and structures thereon to produce and take care of said products, all that certain tract of land situate in the county of ______, state of Kansas, of section ___, township ___, range ___, and containing ___ acres, more or less.
It is agreed that this lease shall remain in force for a term of ___ years from this date, and as long thereafter as oil or gas or either of them is produced from said land by the lessee, his heirs, administrators, executors, successors or assigns. In consideration of the premises the lessee covenants and agrees:
First: To pay to the lessor, as royalty, the equal one-eighth part of the proceeds of all oil produced, saved and sold from the leased premises.
Second: To pay the lessor at the rate of ___ dollars each year, in advance, for the gas from each well, where gas only is found, while the same is being used off the premises, and the lessor to have gas free of cost from any such well for all stoves and all inside lights in the principal dwelling house on said land during the same time, by making his own connections with the well.
Third: To pay the lessor for any gas produced from any oil well and L,sed off the premises, at the rate of ___ dollars per year for the time during which such gas is being used, said payments to be made each three months in advance.
The lessee agrees to complete a well on said leased premises within ______ from the date hereof, or pay the rate of ___ dollars in advance for each additional ___ such completion is delayed from the time above mentioned for the full completion of such well until a well is completed; and it is agreed that the completion of such well shall be and operate as a full liquidation of all rent under this provision during the remainder of the term of this lease.
The lessee shall have the right to use, free of cost, gas, oil and water produced on said land for his operations thereon, except water from wells of the lessor.
When requested by the lessor, the lessee shall bury his pipe lines below plow depth.
No well shall be drilled nearer than 200 feet to the dwelling house or barn on said premises.
The lessee shall pay for damages, caused by drilling, to growing crops on said land.
The lessee shall have the right at any time to remove all machinery and fixtures placed on said premises, including the right to draw and remove casing.
The lessee shall not be bound by any change in the ownership of said land until duly notified of any such change, either by notice in writing duly signed by the parties to the instrument of conveyance, or by receipt of the original instrument of conveyance or a duly certified copy thereof.
If the lessor owns a less interest than the entire and undivided fee simple estate in said land, then the royalties and rentals herein provided shall be paid to the lessor only in the proportion which his interest bears to the entire and undivided fee.
All payments which may fall due under this lease may be made directly to ______ or deposited by the lessee to his credit in ______.
The lessee, his heirs, executors, administrators, successors or assigns, shall have the right, at any time, on the payment of one dollar to the lessor, his heirs or assigns, to surrender this lease for cancellation, after which all payments and liabilities thereafter to accrue under and by virtue of its terms shall cease and determine.
All covenants and agreements herein set forth between the parties hereto shall extend to their respective successors, heirs, executors, administrators and lawful assigns.
IN WITNESS WHEREOF, The said parties have hereunto set their hands the day and year first above written.
Witnesses:
_________ _________
_________ _________
_________ _________
NOTE—The signature by mark of a lessor who cannot write his name must be witnessed by two witnesses, one of whom must write lessor's name near such mark.
ACKNOWLEDGMENT.
STATE OF KANSAS, COUNTY OF ______, SS.
BE IT REMEMBERED, That on this ___ day of ______ A. D. 192 before me, a notary public in and for said county and state, came ______ and ______, who ______ personally known to me to be the same person who executed the within and foregoing instrument, and as such person duly acknowledged the execution of the same.
IN WITNESS WHEREOF, I have hereunto set my hand and affixed my notarial seal, the day and year last above written. ______, Notary Public.
My commission expires ______.
The purchase price of a lease in Kansas generally has a dual consideration—a bonus, or cost for the execution or transfer of the lease; and a yearly rental to the landowner, which applies either until the termination of the lease or until oil or gas are obtained in commercial quantities. When oil or gas is obtained the yearly rental is supplanted by a royalty, or a percentage of the oil and gas marketed. In the case of oil the usual royalty is one-eighth of the oil, and in the case of gas may either be a definite proportion of the marketed production or a definite yearly money rental for each gas well.
The bonus or cost of executing a lease varies greatly, depending in general upon the distance from oil and gas developments. It is the result of a bargain between the landowner and the lessee. For wildcat acreage at a distance from oil and gas fields, the bonus may be as low as $1 per acre, while near a productive well or field it may be several thousand dollars an acre.
The yearly rental which is paid to the fee landowner ranges generally from 50 cents to $1 per acre. Where rapid development is desired by the landowner, a larger rental is frequently obtained as a stimulus to early drilling, but this is offset by a correspondingly lower bonus.
It may not be out of keeping at this place to point out the conditions on which royalties are based. They depend in large measure on the principle that the landowner has an inherent right to a proportion of the profits derived from the output of his property, so that in case his property contains large quantities of valuable minerals his remuneration will be large; and if his property contains but a small mineral value his income will be proportionately small. This indicates that the theoretical basis for royalties is profits, not output; or, in other words, it is on the income in excess of expenses and a normal payment for the involved risks, and not upon the commodities produced which yield no profit to the producer. Although profits form the theoretical basis of royalties, this basis has not been found feasible or practicable in the oil industry in the United States. Several reasons lie back of this condition, the first of which probably is the fact that the property owner and the oil producer are not partners. The one is the owner of small quantities of raw, unmined material; the other is the miner and marketer of small holdings bought from many individuals. Another reason, which applies to conditions in the United States, is that the landowner is usually a farmer, a man who for our present purpose may be said to be familiar only with "small business," whereas the producer is a "big business" man. From the nature of existing conditions, the bookkeeping of an oil and gas enterprise lies in the hands of the producer; and as the intricate bookkeeping is usually beyond the understanding of the landowner, he requires a method of accounting which is not only simple, but which will also not permit the producer to manipulate his accounts to the disadvantage of the landowner. Further, the profits of an oil and gas enterprise can often not be ascertained for months and sometimes years after the oil has been brought to the surface of the ground, and for this delay the landowner does not usually consider himself responsible, nor is he willing to endure the delay.
These and many other considerations existing in the early history of the oil and gas industry brought about a simple division of the oil produced, with the further condition that in case the owner did not care to handle his own portion of the oil thus divided, the operator would buy his portion at the prevailing market price, thus relieving the landowner of all expense and trouble in transporting, storing, and the ultimate marketing of the oil produced.
Undoubtedly, in the early history of the oil-field developments the proportion of the oil which was credited to the property owner varied considerably, but the resultant widespread and almost axiomatic proportion of 12 1/2 per cent (one-eighth) came to be the happy medium for conditions as they exist in this country. This 12 1/2 per cent royalty is so universal in the United States that it is practically a tradition, and departures are exceptional. From a conservational standpoint, low royalties are advantageous to the public, since wells are pumped longer and the extraction is correspondingly more complete where the small royalty makes possible the longer pumping at a profit.
As has been said, the theoretical basis for a royalty of any kind is to be found in the extraordinary profits which in general have prevailed in oil-development enterprises. If profits form the theoretical basis, then it can readily be seen that where profits are small, especially in the developing of unexplored regions far removed from markets and where the cost of development and the hazards of failure are very great, the payment of any royalty whatever, even as low as 1 per cent, may determine the failure of an enterprise. Undoubtedly there are many undeveloped localities in which oil could be exploited to the advantage of the communities immediately interested, by supplying profitable work to the inhabitants, if it were not for the payment of the royalties, which eliminate the profits of the producer. In other words, royalties may prevent the establishment of industries which should by right be fostered. The fostering of an industry may go one step further, as in places where the benefits to be derived by the community are greater than the probable deficits which the operator may entail, under which circumstances an enterprise may require a subsidy of some kind, as preferential tariffs or active financial assistance—a not unlikely possibility for the United States government in the near future in foreign oil enterprises, if the government is at all concerned in the development of its foreign trade in competition with that of other countries. The time may also come when the country's need for oil will be so acute that the government to find new oil territory may be required to finance prospecting before private enterprise will assume the hazards of oil-field development.
In the opposite trend of possibilities, oil and gas properties may be so situated in exceedingly rich and proven districts that the risks involved in a development enterprise are entirely eliminated and the profits are certain to be excessively great. Under such conditions it can readily be seen that royalties in excess of 12 1/2 per cent should be obtained. Although extremes of this type may exist, they are pointed out to indicate that exceptions to the traditional 12 1/2 per cent royalty are possible, and that these exceptions may be in the direction of no royalty at all, and may even go to the extent of necessary subsidizing, or they may be in the direction of high royalties where exceedingly high profits are secured.
Spacing and Drilling of Wells
After obtaining a lease, the next procedure is the drilling of test wells. Unless prevented by contract or other reasons, the initial well is located on the most favorable spot as determined by geologists. In Kansas there are no laws governing the location of wells with respect to land lines, but common sense and recognized practice usually limit the locations to certain arbitrary distances. In the Eldorado field it is the common practice to drill 9 wells to the Stapleton oil zone in each 40-acre tract; that is, at the rate of 1 well to 4 4/9 acres. These are spaced in regular checkerboard fashion, with the outside wells located 200 feet from the land lines. In this fashion 12 boundary-line wells are spaced within the distance of a mile. By mutual agreement between owners of adjacent leases, or where a single owner owns several adjacent leases, the wells may be more widely spaced and be located at greater distances from the boundary lines because of the ultimate greater economy of oil production by this method. In some parts of the Eldorado field where this condition exists the practice is to drill but 4 wells to each 40-acre tract, or at the rate of 1 well to each 10 acres, and to space them 660 feet apart and 330 feet from the land lines. This permits 8 boundary-line wells to the mile.
The 660-foot-sand wells are more closely spaced, but here too the practice varies, depending in general on the extent of the acreage held by a single company. Where adjacent acreage is held by competing companies, 16 wells to a 40-acre tract, or 1 well to 2 1/2 acres, is the general practice, while where one company holds adjacent leases it is the more common practice to space 25 wells to each quarter section, or 1 well for each 6 2/5 acres.
Gas wells are even more widely spaced, but since the reservoirs of gas are more or less local, the location of gas wells is dependent upon the presence of gas rather than upon land lines. Where the gas is more or less evenly distributed, 1 well to 40 acres is generally the practice.
It is the practice in the Eldorado field that wells on adjacent leases are directly opposite each other and at the same distance from the dividing line. It is the practice, also, that when a producing well is completed on a lease an offset well on the adjacent lease is started as soon as practicable. This procedure applies in general only to the border-line wells, but may also apply to the inside drilling locations. Boundary-line wells are almost invariably the first ones drilled, and in places the inside locations are left undrilled. By thus leaving the inside locations undrilled a larger drainage area is given to the boundary-line wells of a property.
Drilling in the Eldorado field is done by the churn method, the Stapleton oil-zone wells being drilled with a standard rig, including calf wheel, while the 660-foot sand and gas wells are generally drilled with portable rigs. It is the general practice to let the drilling of the wells be done by contract at a stipulated price per foot, with fuel, water, casing and rig furnished.
Several companies let the drilling of their wells to contractors to a depth which is considered near to the top of the Stapleton pay, and from there on have special company drillers hired on a time basis to drill into the oil pay. By this procedure the company obtains greater uniformity in the finishing of their wells and greater accuracy and uniformity in the recording of sand data. This probably applies only to the Stapleton oil-zone wells.
Oil Producing
When a flowing well is obtained in the Eldorado field every effort is made to let it produce to its full capacity, provided the output can be cared for. A lack of adequate tankage to hold the production may be sufficient reason to close in a well, but such a procedure is very hazardous and may be disastrous, as was the case when the Empire Gas and Fuel Company's Shriver farm well No. 3, previously cited (northeast corner location, NW, sec. 14, T. 26 S., R. 4 E.), was brought in with a flow of oil which amounted to 144 barrels in 9 minutes, or at the rate of about 23,000 barrels per day. No adequate tankage was immediately available, and instead of permitting the oil to escape down the valley, thereby endangering numerous other wells, the management closed in the well for a few days until this prodigious production could be handled. When reopened, the well, instead of producing oil, flowed salt water. A small production of oil was later obtained. In the flowing Stapleton oil-zone wells the oil is generally permitted to flow directly into a small open tank of 150 or 250 barrels capacity, from which it is pumped into storage reservoirs.
The flush production of the flowing wells is generally short lived, the time being measured generally in weeks rather than in months. [Note: Shumway well No. 5, cited on pages 22 and 23, is the most notable exception to this rule.] When their production has reached a low ebb, or when their initial production is low, most flowing wells are stimulated by swabbing. [A swab is a pumping mechanism attached to the drilling stem which uses the casing as a working barrel. It is raised and lowered in the oil column by the walking beam and in this way assists the flow of oil.] When swabbing is no longer a sufficient stimulus, the well is tubed and rigged for pumping. Those wells whose initial capacity is low are rigged for pumping immediately after being completed. For a short time after being put to pumping, the drilling equipment of steam boiler, engine and walking beam are used for pumping, which as soon as feasible is replaced by a gas engine and pumping jacks. To permit cleaning of the well, the derrick is not removed.
In 1918 electric power began to supplant the gas engines for pumping wells, the innovation being instigated by the rapidly decreasing supply of gas. The success attendant on electrical pumping has resulted in adapting electric power to drilling, where it has proven to be much more economical than steam power (Sevenson, 1919).
The 660-foot-sand wells, with possibly the exception of the first few that flowed when drilled in, are rigged for pumping immediately upon completion. As a general rule they are equipped with pumping jacks operated through shackle lines from centrally located power plants, with a dozen or more wells operated by a single unit. Portable outfits are used for cleaning the wells.
Emulsion Treatment
Much of the oil obtained by pumping is accompanied by salt water in smaller or larger quantities. This water is present not only as an inert substance, in part readily separable through gravitative action, but very often is combined with the oil in an emulsion, generally spoken of as B S, which must be broken down and the water eliminated before the oil can be refined. An emulsion is referred to as temporary emulsion when it will separate into comparatively free oil and water by settling under ordinary temperatures, but when the settling out is negligible, even after a long period of time, it is termed permanent emulsion. A large part of the permanent emulsion can be separated by various physical means into comparatively free petroleum and water, but a small portion, usually less than one per cent, very often is so emulsified that below distillation temperatures it remains in combination.
Emulsion, or B S, as defined by McCoy and Trager (1919; the present discussion is principally a summary of this article), is composed of a physical mixture of water, oil and air, with some included inert matter, either organic or inorganic. These are present as minute globules of water surrounded by films of oil, globules of air surrounded by films of water and oil, and globules of oil. The water in emulsion composes about two-thirds of the mixture. Such a mixture causes a marked increase in the viscosity and specific gravity of petroleum, and it is this thick and more or less gummy material which is the baneful emulsion, or B S, of the oil industry.
According to McCoy and Trager, the mere presence of globules of water and air in petroleum does not cause emulsification, at least not until these globules are packed rather closely together. In heavy oils the globules may be separated by distances several times their diameter, and cause emulsion; but in lighter oils the spacing must be more crowded. The spacing of the globules in the Augusta oil used by McCoy and Trager, which is but slightly different from the Eldorado oil, must be about equal to their diameters before the oil may be said to be emulsified. When the globules are generally less than 0.5 mm. in diameter, the emulsion is of the permanent type. The presence of foreign matter increases the permanency of the emulsion.
Pipe-line companies will not accept crude oil which contains more than a very small percentage of B S, generally about one per cent. This forces the operating companies to separate their oil and B S, and to break up as far as possible the B S into oil and water. In order to keep the production from each lease distinct, so that the correct royalty may be computed, a dehydrating plant is located on each lease.
The oil, B S and water will separate by being allowed to settle in settling tanks, in which the good oil will rise to the top, the water will go to the bottom, and the B S, which has a density between that of oil and water, will take an intermediate position.
The most generally used method for separating the oil and water in emulsion is through the agency of heat, which breaks down the surface tension of the water globules, permitting them to coalesce and form increasingly larger ones, which reach a size that will settle to the bottom of the separating tank and permit the free oil to rise to the top, from which it is drawn off.
The practice generally followed in the Eldorado field is first to pump all the fluid obtained from the wells into a settling tank, from which the separated emulsion is drawn and turned into the bottom of a tank filled with water heated by live steam to a temperature of about 120° to 130° F., through which it rises in small particles after being distributed widely over the base of the tanks by means of radiating lead pipes. In ascending through the heated water the drops and particles of the emulsion are rapidly heated and the oil and water separate more or less. A single treatment of this kind is not sufficient to break up all the temporary B S, hence the oil and B S mixture collecting at the top of the tank is led off to the bottom of a second steaming tank, where the process is repeated in water which is heated 20° to 40° F. higher than that of the first tank. From the second tank the oil and B S mixture is led to a settling tank, where the freed oil, the more permanent B S and the liberated water are permitted to separate. From the settling tanks the good oil is pumped into the field storage, and the more permanent B S, together with a small amount of oil which cannot be well separated from it, is drawn off into earthen sumps, where it is periodically burned. The amount of oil and B S thus burned represents a wastage of about 1 per cent. While this percentage is low, yet it is very considerable when applied to the entire pumped production of the field. The above outlined simple treatment of emulsion is considerably modified in practice. Where the quantity of oil emulsion to be treated is large, specially designed concrete dehydrators are built in which the same steaming principle can be applied more efficiently and economically.
McCoy and Trager (1919) have demonstrated that, although emulsion is essentially a mixture of water and oil, the presence of air or gas is essential to its formation. From field observations they have concluded that when air or gas enter the working barrel of a pumping well, the amount of B S produced is greatly increased; and hence, in pumping a well the fluid level in the well should at no time be permitted to fall below the level of the perforated tubing. The proper rate at which a well should be pumped to produce the least amount of B S is an individual problem for each well and can be determined only by testing. The demonstration that considerable control can be exercised over the amount of B S formed in a pumping well should be welcomed by all operators and should receive the serious attention of conservation commissions.
In this connection attention should also be directed to the progress made in eliminating the entrance of water into the wells. Although the methods employed are extremely technical, their descriptions are pertinent to the subject of water, and are therefore discussed under that subject on pages 172-175.
The oil obtained from any one lease is first placed into measuring tanks whose size conforms to the quantity of oil produced by that property. When the oil in these tanks is to be turned over to a pipe-line company, a gauger measures the oil in the tank or tanks, after which it is turned into the pipe line. Where not sold to a pipe-line company, the oil is loaded by pumping into tank cars for rail shipment.
The pipe-line companies transport the oil either to their affiliated refineries or else place it in storage on their tan-li farms, from which it can be drawn as needed.
Refineries and Pipe Lines
In the immediate vicinity of the Eldorado field are located five or six refineries, which were built primarily to handle Eldorado oil. They are of the skimming-plant type which produce gasoline, kerosene, gas and fuel oil, and distillates. The gas and fuel oil and distillates are sold to large refineries for further separation into lubricating oils, waxes, etc., or else are sold for fuel-oil purposes. The names and locations of these refineries, together with their capacities and locations in the field, are as follows:
| Refineries in Eldorado field. Data furnished by the Bureau of Mines. |
|
|---|---|
| Name and location | Capacity in Barrels, crude oil. |
| Eldorado Refining Company (SE SE, sec. 27, T. 25 S., R. 5 E.) |
1,500 |
| Midland Refining Company (E2 SW, sec. 10, T. 26 S., R. 5 E.) |
3,500 |
| Fidelity Refining Company (Sec. 11, T. 26 S., R. 5 E.) |
2,500 |
| St. Louis Oil & Refining Company | 1,500 |
| Tri-State Oil & Refining Corporation (SW SW, sec. 14, T. 25 S., R. 5 E.) |
1,500 |
| Reliance Refining Company | Building. |
Obviously these refineries can handle but a small part of the Eldorado production. The remainder is sold either to small near-by refineries, most of which receive their crude-oil shipments by tank cars, or to the large pipe-line companies for distribution to their associated refineries. Five or more of these small refineries are located at Wichita, a city of —— population located twenty-five miles west of Eldorado. Among the large pipe-line companies which take oil from the Eldorado field are the following:
| The Prairie Pipe Line Company. |
| The Sinclair Pipe Line Company. |
| The Gulf Pipe Line Company. |
| The Empire Pipe Line Company. |
| The Oklahoma Pipe Line Company. |
The small refineries built in the neighborhood of an oil field during its development are generally of the skimming type, in contrast to the complete refinery; that is, they distill off only the higher fractions of the crude oil, gasoline and kerosene, and sell and ship by tank cars the remainder, very often to complete refineries equipped for making lubricating oils and waxes. [Note: The percentages of the products obtained by the skimming plants under current practice have been given on page 168.] The liquid products of refining are generally shipped to distributing stations by tank cars, and for this purpose large fleets of tank cars are operated by the larger refining interests.
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Kansas Geological Survey, Geology
Placed on web July 28, 2017; originally published 1921.
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