PETROLEUM-COMPOSITION tion. Heating under pressure for many hours to effect appreciable decomposition a t temperatures at which control tests in the absence of catalysts may have no effect. The time element in tests a t the temperature of reservoir rocks and with moist natural minerals is evidently far outside experimental possibilities. 4. Discover and isolate material intermediate between organic matter in contemporary or recent marine sediments and heavy crude oils, as suggested by Barton. Extraction of disseminated material would probably be necessary.
Hobson, G. D., “Science of Petroleum,” p. 54, London, New York, Oxford University Press, 1937. McCoy, A. W., and Keyte, W. A., Bull. Am. Assoc. Petroleum Geol.. 28.253 (1934).
McKiniey,’J. B:, Stevens, D. R., and Baldwin, W. E., J . Am. Chem. Soc., 67, 1455 (1945).
McNab, J. G., Smith, P. V., and Betts, R. L., IND.ENO.CHEM. 44, 2556 (1952).
Milliken, T. H., Mills, G. A., and Oblad, A. G., Discussions Faraday SOC.,8,279 (1950).
Panchenkov, G., et al., Doklady Akad. N a u k S.S.S.R.,78,
REFERENCES
501-4 (1951).
( 1 ) Bartlett, P. D., Condon, F. E., and Schneider, A., J. Am. Chem,
SOC.,66,1531 (1944).
(2) (3) (4) (5)
Barton, D. C., Bull. Am. Assoc. Petroleum Geol., 28, 109 (1934). Barton, D. C., J . Inst. Petroleum, 20, 206 (1934). Belser, C., Mining and Met., 29, 2358 (1948). Bornhauser, M., Bull. Am. Inst. Petroleum Geol., 34, 1887 (1950).
(6) (7) (8) (9) (10) (11)
(12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29)
Brooks, B. T., Bull. Am. Inst. Petroleum Geol., 15, 611 (1931). Ibid., 32,2272 (1948). Ibid., 33,1600 (1949). Brooks, B. T., J . Inst. PetroEeztm, 20, 177 (1934). Brooks, B. T., Science, 111, 648 (1950); 114, 240 (1951). Brooks, B. T., “Science of Petroleum,” p. 46, London, New York, Oxford University Press, 1937. Caesar, P. D., and Francis, A. W., IND. ENG.CHEM.,33, 1426 (1941). Chibnall, A. C., Piper, S. H., et al., Biochem. J . , 25, 2175, 2189 (1934). Ciappeta, F. G., IND. ENG.CHEM.,37, 1210 (1945). Conant, J. B., and Petersen, W., Can. J . Research, 34, 921 (1934). Cox, B. B., Weaver, P., Hanson, W. E., and Hanna, M. A., paper presented a t 120th Meeting AM.CHEM.Soc., New York, September 1951. Danforth, J. D., private communication. Danforth, J. D., Demorest, M., and Mooberry, D., IND.ENG. CHEM.,43,2569 (1951). Davidson, R. C., Ewing, F. J., and Shute, R. S., Natl. Petroleum News, No. 27R, 318 (1943). Francis, A. W., IND. ENG.CHEM.,20, 277 (1928). Fred, M., and Putscher, R., Anal. Chem., 21, 900 (1949). Frost, A. V., Uspekhi Khim., 14, 501-9 (1945). Frost, A. V., et al., Doklady Akad. Nauk. S.S.S.R., 78, 509-12 (1951). Gayer, F. H., IND. ENG.CHEM.,25, 1122 (1933). Glazebrook, A. L., and Lovell, W. G., J. Am. Chem. Soc., 61, 1717 (1939). Greensfelder, B. S., Advances in Chem. Ser., 5, 3 (1951). Greensfelder, B. S., Voge, H. H., and Good, G. M., IND. ENG. CHEM.,41,2573 (1949). Grenall, A., Ibid., 41, 1485 (1949). Haak, F. A., and Van Nes, K., J . Inst. Petroleum, 37,245 (1951).
.
Pines, H., and Wacker, R. C., J. Am. Chem. SOC.,68,595 (1946). Sachanen, A. N., “Chemical Constituents of Petroleum,” pp. 203,214, New York, Reinhold Publishing Co., 1945. Sachanen, A. N., and Caesar, A. D., IND.ENG.CHEM.,38, 43 (1946).
Schmerhg, L., J. Am. Chem. SOC.,67, 1438, 1778 (1945); 68, 195,275 (1946).
Seyer, W. F., J. Inst. Petroleum, 19, 733 (1933). Sheppard. C. W., and Burton, V. L., J . Am. Chem. Soc.. 68, 1636 (1946).
Stadnikoff, G., “Die Entstehung von Kohle n. Erdoel,” pp. 148-52, Stuttgart, Ferdinand Enke, 1930. Stadnikoff, G., and Weizmann, A., Brennstoff-Chem., 10, 401 (1 929).
Stevens, P. G., J . Am. Chem. Soc., 67, 908 (1945). Stevens, P. G., and Spalding, S. C., Ibid., 71, 1687 (1949). Tamele, M. W., Discussions Faraday SOC.,8, 270 (1950). Taylor, H., and Turkevitch, S. L., Trans. Faraday Soc., 35, 921 (1939).
Thomas, C. L., IND. ENG.CHEM.,41, 2571 (1949). Thomas, C. L., Bickey, J., and Steoker, G., Ibdd., 42, 866 (1950).
Thompson, A. B., “Oil Field Exploration and Development,” p. 42, New York, D. Van Nostrand Go., 1925. Trask, P. D., Bull. Am. Assoc. Petroleum Geol., 14, 1451 (1930); 23,428 (1939).
Trask, P. D., “Science of Petroleum,” p. 42, London, Oxford University Press, 1937. Treibs, A,, Ann. Chem., 410, 42 (1934); 517, 172 (1935); 520, 144 (1935).
Van Nee, K., and Van Westen, H. A., “The Constitution of Mineral Oils,” p. 41, Houston, 1951. Walling, C., J. Am. Chem. SOC.,72, 1164 (1950). Whitmore, F. C., Chem. Eng. News, 26, 668 (1948). Whitmore, F. C., IND. ENG.CHEM.,26, 94 (1934). Whitmore, F. C., J. Am. Chem. Soc., 54,3274 (1932). Whitmore, F. C., and Cook, N. C., “Science of Petroleum,” Vol. V, p. 114, London, Oxford University Press, 1950. RECBIYED for review December 6, 1951. ACCEPTEDJuly 30, 1952. Presented as part of the Symposium on the Origin of Petroleum before the Division of Petroleum Chemistry at the 120th Meeting of the AMERICAN CHEMICAL SOCIETY, New York, September, 1951.
COMPOSITION OF PETROLEUM
Composition of United States Crude Oils HAROLD M. SMITH U. S. Bureau of Mines, Petroleum Experiment Station, Bartlesville, Okla.
T
HE composition of petroleum is a subject that has intrigued petroleum chemists for many, many years, starting even before the discovery of the Drake well (but reported later) with work by the American chemist, Silliman (11). Since that time many chemists, both from the United States and foreign countries, have studied petroleum with a view to ascertaining its composition, and some excellent work has been done, It is beyond the scope of this paper to record this work, but a few of the more recent researches or compilations reporting accumulated research may be mentioned. Gruse and Stevens (4) give a good resume of the status of knowledge in this field as it existed about 1940. “Science of Petroleum’’ (IO) contains several articles deNovember 1952
scribing the characteristics of both United States and foreign crude oils. This material reflected information available in t h e latter half of the 1930’s. Sachanen ( 9 ) in 1945 devoted an entire book to the chemical constituents of petroleum and this probably represents the most thorough compilation of these data t h a t has been made. A study of these references indicates t h a t the authors use two general sources of data-information collected from analyses of the routine type, such as those published in the crude oil surveys of the Bureau of Mines, and the results of detailed studies of individual crude oils or fractions of crude oils. Probably the most notable example of this latter type of research is t h a t of API
INDUSTRIAL AND ENGINEERING CHEMISTRY
2577
Research Project 6 by Rossini and his associates a t the Bureau of Standards (now a t Carnegie Institute of Technology), of which a very good resume is given in ('J 8). It has only recently become possible, however, t o attempt a correlated review of the crude oils of any one area, to say nothing of an entire country.
elemental sulfur and in sulfur compounds is the subject of another paper ( 2 ) * Viscosity. The viscosity used is stated in terms of Saybolt ~ ~seconds i ~at 1000 ~ F., ~ as~ determined ~ l on the crude This property helps t o establish the visual picture of the oils under discussion. Asphalt. This is the content of 100-penetration (at 77' F.) It is the purpose of this present article t o present such a review asphalt. It is estimated from data presented by stanfield and on a statistical basis for the United States. Analytical methods Hubbard ( I d ) , which indicate that the percentage asphalt of for studying petroleum have this penetration can be approximated for comparative advanced greatly during the T h e crude oil-producing areas of the United States are last decade, and it is nox- pospurposes carbon residue by multiplying of the crude the sible to correlate certain of the divided into eight geographical areas. Certain characterisoil by 4.9. results of these analytical tics of the crude oils produced in each area are discussed Naphtha. T h e n a p h t h a in this paper. Characteristics, based on the Bureau of methods with the routine ~~~~~~~e~ ~ ~ e ~ ~ ~ , " $ ~ l a analyses which the Bureau of Mines routine analysis, include the sulfur, asphalt, n1ines routine analysis at a Mines has made on many naphtha, gas oil, aromatics in both the naphthas and gas vapor temperature of 200" C. thousands of crudeoils. The oils, and naphthene ring in the paraffin-naphthene par(392' F.1. I t includes the first seven fractions obtained correlations used admittedly tions of both the naphthas and the gas oils. A total of by this method of distillation. 330 crude oils is included in the discussion. h a v e s h o r t c o m i n g s , and Gas Oil. Gas oil is conthese will be pointed out in sidered to be the material distilling between 200" C. the course of the discussion. I t is believed, however, that for an initial review the results (392' F.)at atmospheric pressure and 225" C. (437' F.)at 40 mm. This represent fractions 8, 9, and 10 of the Bureau of Mines certainly justify consideration. routine distillation obtained a t atmospheric pressure, and fractions 11 and 12, which are obtained at 40 mm. pressure. GEOGRAPHICAL COVERAGE Comparison of these properties in 330 crude oils are given in T o facilitate comparison of crude oils produced in various sections of the United States, the country has been divided on a geographical basis into eight areas (see ~i~~~~ 1). Starting with the west coast and moving eastward these areas are: California; Rocky Mountain, nThich includes Colorado, Wyoming, and Mantans; West Texas,which includes %,hat is usually termed q T e s t T ~ ~ and ~ ~ the J adjacent J fields in N~~ ~ ~the T~~~~ ~ pani handle, and in the newly discovered Scurry County district of T ~ ~ ~~ coast, l ~ f rt.hich ~ is; a belt approximate]y 50 miles wide along the coast of Texas and Louisiana; Mid-Continent, a rather large and heterogeneous area which includes all of Texas not included in West Texas or Gulf Coast, and all of Oklahonia, Kansas, Arkansas, and Illinois as well as Southviest Indiana and northern Louisiana; Mississippi, to which is added one field in Alabama; Michigan, which also includes northern Ohio and Indiana; and Appalachian, in which are grouped Pennsylvania, New York, and West Virginia as well as eastern Ohio and Kentucky. Some minor fields in other states have been included in the appropriate areas, but their production is so small that they become negligible in the whole picture. The map shown in Figure 1 illustrates the areas t h a t have just been mentioned and shows the percentage of the total United States production assigned to each district. These data ale given also in Table I together with the percentage of the production in each area represented by analyses in this study. The production data are for the year 1950. Smith ( I d ) gives tabulated data on 279 crude oils of the United States. I n the present study virtually all of the crude oils discussed in t h a t article are considered, plus about 60 more, for a total of 330 crude oils. T h e number of fields represented by these analyses are given also in Table I. This coverage includes virtually all fields t h a t produce 2500 barrels per day or more. COMMERCIAL CHARACTERISTICS
Certain properties of crude oils can be considered as commercial characteristics as contrasted to the hydrocarbon-type composition t h a t will be discussed later. Among the more important of these properties are API gravity, sulfur content, viscosity, asphalt content, naphtha content, and gas oil content.
API gravity. The API gravity of the crude Oil is t h a t determined at the time of analysis. Sulfur. This is simply weight per cent total sulfur in the crude oil. The distribution of this sulfur in the crude oil as
2578
'.
Figures to Figure 2 s h o ~ the s distribution O f crude oils according to APT gravity. The gravities have been grouped as follo~vs:less than 15, 15 t o 25, 25 t o 35, 35 to 45, and over 45 (see symbols a t right of Chart). The vertical scale of each bar graph represents the per cent of crude oil produced in t h a t area t h a t conforms to the characteristics indicated. Only California and West Texas ~ ~ , areas produce Oil of less than 15 API gravity, and there only in limited quantities. The heavier characteristics of California and
Table 1. United States Crude Oil Production Covered by This Study Area California Rocky Mountain West Texas Gulf Coast Mid-Continent
gi$!Fz Appalachian
United States Production in Area, % 15 55 4 45 2 1 15 22 20
32 1 0 I
81 90 88 06
Area Production Number of Ficlds Represented by Represented by Anabses, 5% Analyses 92 58 62 63 64
54 89 40
78
17
45
102 88 9 9 2
West Texas oils are shown by rather large quantities of oil in the 15 t o 25 B P I gravity group, and California is the only area that has less than 20% of its production in the 35 t o 45 $PI gravity class. Gulf Coast oils are about equally divided between those oils in the 35 to 45 and 25 to 35 API gravity groups. In some instances API gravity can be correlated roughly with sulfur contents, asphalt contents, naphtha contents, and parafinicity. Thus the high-sulfur areas such as California, West Texas, and Mississippi have lower BPI gravity oils. I n the Rocky Mountain area the effects of high sulfur are somewhat hidden by the relatively high paraffin content of the naphthas and gas oils. Similarly, West Texas has a large quantity of high gravity oils because of the high content of naphtha of high paraffinicity. These and other relationships can be traced by colnparing Figure 2 with the bar graphs on other properties. For the entire country 50% of the crude oils is in the 35 to 45 API gravity group and almost 30% in the25 to a5 group. Figure 3 shows the distribution of sulfur in the crude oils of the United States. In this chart the weight per cent of sulfur has been considered under the percentage ranges of under 0.25, 0.25 to 0.5, 0.6 to 1.0, 1.0 to 2.0, and over 2.0. Inasmuch as the dark areas on the graphs represent crude oils having over 2%
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 44, No. 11
PETROLEUM-COMPOSITION +i
m
5
November 1952
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
2579
100
*wa. a
A P I GR4VlTY
EO
5 D
U w
3
60
,x
2
$ 8 8
*
40
20
g a
0
Distribution of API Gravity among Crude Oils of the United States
Figure 2.
of sulfur, it is apparent t h a t crude oils of this nature are found in a number of parts of the United States, notably California, Rocky Mountain, West Texas, Mid-Continent, and Mississippi, but in terms of production probably the California, West Texas, and Mid-Continent areas are the most important. If 0.5% sulfur is considered as the dividing line between a low- and a high-sulfur crude oil, it is seen that the percentage of production in the several areas falling in the high-sulfur category is as follows: 7Oy0 in California, about SO% in the Rocky Mountain area, 50% in West Texas, none in Gulf Coast, only about 25% in the MidContinent area. about 65 % in Xssissippi, and approximately
WEIGHT PERCENT SULFUR
0
UNDER 0 2 5
025-050
05 -10 10 - 2 0 OVER 2 0
nationally. On a countrywide basis, about 36% of the sulfurbearing crude oils are 0.5% or higher, leaving about 65% in the low-sulfur category. Figure 4 shows the distribution of asphalt in the crude oils of the United States as calculated according to the method explained above. The asphalt content has been divided into percentage groups of crude oils having less than 5%, and those having 5 to 10, 10 to 15, 15 to 25, and above 25%. To a considerable extent, petroleum chemists have associated high asphalt contents n-ith high sulfur contents, and asphalt would therefore be expected to be prevalent where there are high-sulfur crude oils. This chart indicates that this is generally true, but that high sulfur content and high asphalt content are not always associated, as the hgures for California oils shov approxiinately 30% of crude oils having asphalt of higher than 2570, yet their production of crude oils having 2% sulfur or higher was relatively small. Other areas that produce crude oils having high contents of asphalt are Rocky Mountain, West Texas, Mid-Continent, and Mississippi. Low contents of asphalt, 10% or less, are found in crude oils from about 60% of the West Texas area, almost the entire Gulf Coast area, about 2 5 % of the Mid-Continent area, and considerable portions of the Mississippi, Michigan, and Appalachian areas. On a countrywide basis, about 11% of the crude oils produced contain over 25% asphalt, about 43% have between 10 and 25% asphalt, and about 4670 have less than 10% asphalt. I n addition to sulfur, nitiogen has also been found associated with asphalts. I n a recent paper by Ball (5) the nitrogen content of United States crude oils was discussed and its relationship to the residuum, or more particularly to the carbon residue of the crude oil, was pointed out. The coverage in this survey was not so great as in the present study, and it was not possible to make a detailed analysis on the same basis as that for the properties being considered here. However, Table I1 shows the number of fields in each area producing crude oil having nitrogen contents within the limits indicated. It mill be noted t h a t all of the high nitrogen oils are in California, that is, all those having over 0.5% nitrogen, and those having 0.2 to 0 . 5 % nitrogen are largely in California and Wyoming, with a few in the West Texas and Mid-Continent areas. The crude oils of the California, Mississippi, Rocky Mountain, and Mid-Continent areas are also represented in the 0.1 to 0.2% nitrogen content classification. Thus all of the areas having crude oils with a high content of asphalt can be associated with crude oil production having a nitrogen content of 0.1% and greater. In contrast to the Gulf Coast area, many parts of the Mid-Continent area and the eastr ern areas are almost all uniformly low- in nitrogen content-less than O.lO~o-and also low in asphalt content.
A S P H A L T CONTENT PERCENT
W 0
0
t
5 1555
445
Figure 3.
2 1 1 5 2220
3281
190
088
106
100
PERCENT OF USPRODUCTION
2580
5
5-10
Distribution of Sulfur in Crude Oils of the United States
45% in Michigan. In contrast, if low-sulfur crude oils are the objective, several sources are self-evident. One, of course, is the Gulf Coast area; another is the Mid-Continent area, where about 75% of the production falls in this category; also about 50% of the West Texas production is nom in this class, because of crude oils from the Ellenberger formation and from the Canyon Reef producing area in and near Scurry County. Mississippi is a state of contrast and approximately one third of its production has a very low sulfur content. Of course, the Michigan and the Appalachian areas also contribute to the low-sulfur crude oil production, although their production is rather insignificant
c
10-15
15-25
Figure 4.
Distribution of Asphalt in Crude Oils of the United States
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 44, No. 11
PETROLEUM-COMPOSITION T a b l e 11.
N i t r o g e n C o n t e n t of Crude Oils
Nitrogen Content, %
Number of Fields 2 1 1 2
Location of Field Arkansas California Colorado Louisiana Mississippi Montana New Mexico New York Oklahoma Texas Utah Wyoming Arkansas Colorado Illinois Louisiana Mississiuui MontaniNew Mexico Oklahoma Texas Wyoming California Illinois Indiana Kanaas Kentucky Michigan Mississippi Oklahoma Texas Wyoming California New Mexico Oklahoma, Wyoming California
O. 50
1
3 5
1
2
29 1 14 4
2 3 2 1 1 3 3 8 8
5
10
1 2
9 6
The viscosities of the crude oils of the United States have been divided into the following categories: less than 50, 50 to 100, 100 to 200, 200 to 500, and over 500 Saybolt seconds. The areas that produce very viscous crude oils, as shown in Figure 5, are California, Mississippi, and (to a limited extent) the MidContinent area. If a viscosity of 100 seconds is arbitrarily selected as the dividing line between a relatively nonviscous crude oil and one that is fairly heavy and viscous, i t develops t h a t approximately 48% of the California production is of the viscous type and that the same figure applies to Mississippi. I n contrast, the MidContinent production of Viscous material is only about IS%, the Rocky Mountain about 12%, and in other areas it is either missing or negligible. This classification according to viscosity, of course, can be misinterpreted. I n general, in California and Mid-Continent crude oils high viscosity is caused by dissolved asphalt, but in certain areas-for instance, in the small amount of viscous crude oil on the Gulf Coast-it is because of the pres-
ence of viscous liquid hydrocarbons rather than of asphalt. On a countrywide basis there is less than 4% of very viscous crude oil produced. I n fact, only about 15% has a viscosity of 100 or higher, leaving a balance of about 85% t h a t has 100 seconds or less. The naphtha content of United States crude oils (Figure 6) has been divided into following percentage classes of less than 10, 10 to 20, 20 to 30, 30 to 40, and over 40%. The bar graphs indicate t h a t in almost every area there is some production of crude oil having over 40% naphtha. The most notable area, in terms of production, is West Texas, where approximately 26% of the crude oil has over 40% naphtha. California, Gulf Coast, and Mid-Continent areas also have some production in this classification. Certain areas have considerable production whose naphtha content is small. I n California, for instance, 12% of the production contains less than 10% naphtha. The Gulf Coast has a somewhat similar situation. Looking at the United States as a whole, two categories, 20 to 30% and 30 t o 40% naphtha, account for almost 70% of the production of the United States. The class containing more than 40% naphtha is about 10% of the production, and the balance is in the 85 B of the other curves level out perceptibly after the third or fourth 15-20 8 0 - 8 5 fractions, although crude oils from the Coles Levee, East Texas, Conroe, and Slaughter fields are in the range of from 28 to 35% 20-25 75-80 naphthene ring as contrasted to the 20% in Bradford crude oil. x 40 Crude oils from Midway-Sunset (California) field, Hastings 5! 25-30 70-76 (Gulf Coast) field, and the Yates (West Texas) field have much 5 20 w higher contents of naphthene rings, in the case of the Midway>30 5 0 < 5 0 V cc production falls in this classification, about R W 34% of the Rocky Mountain region, 20% of the 0 West Texas region, 47y0 of the Gulf Coast c W 69 region, but only 7% of the Mid-Continent z i 1 2 region, and none of the Mississippi, Michigan, or Appalachian areas. If one is looking then for a naphthenic gas oil, first choice would be ' % t O a z California, and second choice would be Gulf PERCENT OF Coast. If, conversely, one is looking for para1555 4 4 5 21 15 2 2 2 0 32.81 190 088 106 100 U S PRODUCTION ffinic gas oils, Mississippi, Michigan, and A p Figure 13. Distribution of Naphthene Rings and Paraffins plus Side Chains in Paraffin-Naphthene Portion of Naphthas f r o m Crude Oils of palachian areas, the Mid-Continent area, the United States and t o a considerable extent the Rocky Mountain and Gulf Coast areas furnish such naphthas. Inasmuch as this entire paper in realitv reviens the present shown. I n Figure 13, the weight per cent of ring in the parafinknowledge regarding the type composition of United States naphthene portion has been divided into percentage categories of crude oils, it seems unnecessary to give a formal summary. up to 20, 20 to 30, 30 to 40, 40 to 50, and above 50. The bar It was hoped when this paper was started that a table could be graphs show t h a t the only places where the paraffin-naphthene prepared showing the limits within which the various characportions of the naphthas have over 50% of ring are California, teristics of a crude oil fell m-ithin certain areas. However, study where approximately 6% are in this category, and the Gulf of the data indicated that it is impossible t o make satisfactory Coast, with about 1%. If a ring content of 3070 or higher of the limits tor almost any of the areas, with the possible exception of paraffin-naphthene portions is considered, it develops that ahout one like the Appalachian where there is not much change. The 91% of the California production will be of this type, about 7 % other areas have enough variety in one property or another so of the Rocky Mountain, about 10% of the West Texas area, that selection of suitable limits for that area would be misleading. about 42% of the Gulf Coast area, 5% of the Mid-Continent It would be possible, if there were a need for it, to weight the area, and about 15% of the b k h i g a n production. I n contrast, percentage of each category in terms of its production in the i f one is looking for paraffins and paraffin side chains, one would United States and arrive at an average figure for the naphtha, find them predominantly in the Mississippi, Michigan, and hp the gas oil, and each of the properties. This would be a very palachian naphthas, and to a considerable extent in certain Rocky Mountain, Mid-Continent, West Texas, and Gulf Coast naphthas. Gulf Coast crude oils are generally considered to be quite naphthenic 4 100 n W and indeed in terms of the ring content of the 2 paraffin-naphthene portion of the naphthas in WEIGHT PERCENT z RING PARAFFIN 0 so comparison with Mid-Continent production, they W show considerable increase in naphthenicity. V a 0 This is, however, not as much as one might ex60 pect, especially in comparison with the California 20-30 70-80 2 naphthas, and the writer suggests that possibly 0 W one explanation of this lies in the fact that in 30-40 60-70 2 40 this discussion weight per cent of ring is being V used and not volume content of naphthenes and ii 0 40-50 50-60 that the naphthenes from the Gulf Coast area 5 20 may be more predominantly monocyclic rings W with long side chains as contrasted to poly0 W cyclic rings with shorter side chains in the 0 California distillates. This, however, remains to L W v) be proved. Figure 14 shows the distribution of the naph5 z thene rings and the paraffins plus paraffin side d 4 0 2 chains in the paraffin-naphthene portions of k k A 0 gas oils from United States crude oils. In this V 3 PERCENT OF connection, the categories for per cent of ring FC 445 2115 2 P 20 3281 190 ORB I OS 100 U S PRODUCTION are less than 'O' 2o to 30' 30 to 40J 40 to Figure 14. Distribution of Naphthene Rings and Paraffins plus Side 501 and greater than j0. These are the Same Chains i n Paraffin-Naphthene Portion of Gas Oils from Crude Oils of ranges t h a t were used for the naphtha, and the United States a
I00
d W
a
Im . 2C - 4
2584
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 44, No. 11
PETROLEUM-COMPOSITION fictional crude oil, but i t might have some value in predicting trends in refining or other usgs. ACKNOWLEDGMENT
The author is very grateful to C. M. McKinney, Ella Mae Shelton, and Tom Felton, who have contributed to this paper by making many of the calculations and correlations that were required, and also to many colleagues in the Bureau of Mines who, during the past decade or more, have been making Bureau of Mines routine crude-oil analyses upon which many of the data presented in this report are based. LITERATURE CITED
sot. Test. ~ ~ ~‘ ~ A~S ~Standards,” M ~ i ~part l5, D ~ ~ , nation D 875-46T, Philadelphia, Pa., 1949. (2) Ball, J. S., Rall, H. T., Waddington, G., andsmith, H. M., paper presented a t Symposium on Composition of Petroleum, Petroleum Division, 119th Meeting AM. CHEM.Soc., Cleveland, April 1961. (1) Am.
i
(3) Ball, J. S., Whisman, M. L., and Wenger, W. J., Anal. Chem., 23,1632-41 (November 1951). (4) Gruse, W. A., and Stevens, D. R., “The Chemical Technology of Petroleum,” New York, McGraw-Hill Book Co., 1942. (5) Holliman, W. C., Smith, H. M., McKinney, C. M., and Sponsler, C. R.. U. S. Bur. Mines. Tech. Paver 722 11950). (6) Lipkin,’M. R., Martin, L. C., and-Kurtz, S. S.,’Jr., IND. ENG. CHEM.,ANAL.ED., 18, 376 (1946). (7) Mair, B. J., and Rossini, F. D., “Science of Petroleum,” Vol. V, p. 126, New York, Oxford University Press, 1950. (8) Sachanen, A. N., 1bid., p. 53. (9) Sachanen, A. N., “The Chemical Constituents of Petroleum,” New York, Reinhold Publishing Corp., 1945. (10) “Science of Petroleum,” Vol. 11, pp. 839-930, New York, Ox.ford University Press, 1938. (11) Silliman, B., Am. Chemist,2,18 (1871-2). (12) . . Smith. H. M.. “Science of Petroleum.” Vol. V, p. 1, New York, Oxford University Press, 1950. (13) Smith, H. M., U. S. Bur. Mines, Tech. Paper610 (1940). (14) Stanfield, K. E. and Hubbard, R. L.,Ibid., 717 (1949).
~
~
~
-
RECEIVED for review June 25, 1951. ACCEFTEDAugust 11, 1952. Presented a8 part of the Symposium on Composition of Petroleum and Its Hydrooarbon Derivatives before the Division of Petroleum Chemistry a t the 119th Meeting of the AMERICAN CHEMICAL SOCIETY,Cleveland, Ohio, April 1951.
Metalliferous Substances Adsorbed at Crude Petroleum-Water Interfaces CHARLES C. DODD’ AND JOHN W. MOORE Petroleum Experiment Station, Bureau of Mines, U. S. Department of the Interior, Bartlesuille, Okla. MILTON 0. DENEKAS Department of Chemistry, University of Tulsa, Tulsa 4, Okla.
3
Film-forming and surface active constituents in crude petroleum affect the flow of fluids in petroleum reservoirs and the analysis of reservoir rock core samples. The discovery of metallic elements in these substances has stimulated a study of the nature of the interfacially active materials with respect to the role of the metals. Compounds of zinc, copper, nickel, titanium, calcium, and magnesium were found to be adsorbed selectively at petroleum-water interfaces; vanadium was adsorbed to a minor extent and iron to an intermediate degree. The results indicate that
all eight elements occur in petroleum in oil-soluble forms, possibly as porphyrin-metal chelate complexes or other complexes with nitrogen-containing compounds. Although inconclusive, the results support the assumption that film-forming and surface active constituents of petroleum result from biochemical diagenesis of organic matter in sediments. The films may consist of waxes and resins with stabilizing porphyrin-metal complexes. Free porphyrins, porphyrin ring oxidation products, and protein-metal salts or complexes also may be present.
T
presence is undesirable. Finally, i t was thought t h a t efforts aimed a t more complete knowledge of the occurrence of metals in petroleum might provide insight into the problem of the origin of petroleum. A previous publication (4) described early work on crude petroleum produced in the Oklahoma City field. The bulk of material isolated by adsorption a t a n extended crude oil-water interface was identified as a mixture of normal paraffins of unusually high molecular weight containing 50 t o 70 carbon atoms per molecule and melting at 95” to 108”C. In addition, minute amounts of other materials present were moderately surface active and burned t o a black ash insoluble in dilute hydrochloric acid. Subsequent studies of materials isolated from a Rio Bravo, Calif, oil b y adsorption a t oil-water interfaces have disclosed the presence of smaller amounts of giant normal paraffins and appre ciably greater quantities of film-forming and surface active mate-
HE isolation and identification of naturally occurring filmforming and surface active constituents in crude petroleum have been among objectives of this laboratory. Primary impetus for such a study resulted from considerations of the possible effect of these substances on the wetting of petroleum reservoir rock by oil and water. Of interest also in petroleum production-engineering work is the manner in which these constituents complicate the analysis of core samples in the laboratory and cause the formation of stock-tank emulsions in the field. Discovery of the metal content of these materials indicated t h a t their study would be of interest to those concerned with a current problem of the petroleum refining industry involving the analysis and control or removal of trace (or larger) quantities of metals in crude oils. Metals in petroleum poison cracking catalysts and are carried over into certain refined products where their 1 Present
address, Continental Oil Co., Ponca City, Okla.
November 1952
INDUSTRIAL AND ENGINEERING CHEMISTRY
2585
