Diffusion of Hydrocarbon Gases into Oils and Oil Sands Citation Hill, Earl S. (1931) Diffusion of Hydrocarbon Gases into Oils and Oil Sands. Master's thesis, California Institute of Technology. doi:10.7907/ee00-6h79. https://resolver.caltech.edu/CaltechTHESIS:08262024-215224028 Abstract No abstract. Item Type: Thesis (Master's thesis) Subject Keywords: (Chemical Engineering) Degree Grantor: California Institute of Technology Division: Chemistry and Chemical Engineering Major Option: Chemical Engineering Thesis Availability: Public (worldwide access) Research Advisor(s): Lacey, William Noble Thesis Committee: Unknown, Unknown Defense Date: 1 January 1931 Funders: Funding Agency Grant Number American Petroleum Institute UNSPECIFIED Record Number: CaltechTHESIS:08262024-215224028 Persistent URL: https://resolver.caltech.edu/CaltechTHESIS:08262024-215224028 DOI: 10.7907/ee00-6h79 Default Usage Policy: No commercial reproduction, distribution, display or performance rights in this work are provided. ID Code: 16669 Collection: CaltechTHESIS Deposited By: Benjamin Perez Deposited On: 27 Aug 2024 23:15 Last Modified: 27 Aug 2024 23:15 Thesis Files PDF - Final Version See Usage Policy. 11MB Repository Staff Only: item control page

Diffusion of Hydrocarbon Gases into Oils and Oil Sands Thesis by Earl S. Hill In Partial Fulfillment of the Requirements for the Degree of Master of Science in Chemical Engineering California Institute of Technology Pasadena, California 1931 DiffUsion of Hydrocarbon Gases into Oils and 011 Sands Introduction The increasing use of repressuring operations as a means of increasing the recovery of petroleum from oil fields, and the practice of storing oil and gas in formations of known limited extent make it extremely important to know as accurately as possible how long it will take for the gas to diffuse into the formation. The equations for the diffusion of a gas into a liquid hydro.. carbon have be~n developed by Nathan F. Scudder {1) and extended and simplified by Richard D. Pomeroy ( 2). The simplified forms used in 1he calculations are, for a column of liquid of infinite length, where Q = quantity of gas diffUsing through the surface Cs= solubility of the gas in the oil A= area of the surface t . = time D ~ absolute diffusion constant. For For a column of finite length after 50;0 saturation the simplified equation is where Q8 = quantity of gas re quired to saturate the body of oi 1 1 = final length of the column of oil. · Description of Materials Liquid hydrocarbons representing a wide range of densities and composition were prepared or purchased. with a B.P. of 79.4 - The high g-a.soline fraction ss.5°c at 38 mm., and the heptane fraction, B.P. 0 97.5 - 99 c. were prepared by F. P. Stapp (3). Pure cyclohexane i B.P. eo.s 0c, and hexane, B.P. ss.s 0c were purchased from the Eastman Kodak Co. Isopentane, B.P. 27.3 - 2e.2°c, was prepared by redistilling a 5 g-a.llon lot of casing head gasoline from Santa Fe Springs No. 4, Standard Gasoline Co. This distillation was carried out with a 9 ft. glass ring paoked column jacketed with asbestos to prevent heat loss. Ice water was circulated thru the reflux condenser and the final condenser with an air lift. The distillation was repeated 7 times giving isopentane that should be nearly as pure as the other pure hydrocarbons used. A purified oil with a high density, used for medicinal purposes, called liquid petrolateum,was purchased. The density of this oil is above that of any paraffins that are liquid at ordinary temperatures. Hence, it probably has been prepared from a napthene base crude and contains a high percentage of napthenes. The crude oil s~mples were from widely scattered fields as follows: Lina, Ohio, from Ohio Oil Co., 38.4° A.P.I. 60°F. Santa Fe Springs, Cal., from Shell Oil Co., Sample No. 9x94, tank farm, tank No. 502, 33.0° A.P.I. 60°F. Bartlesville, Okla. from u. s. Bur. of Mines, 32.6° A.P.I. 60°F. Bradford, Pa. from Forest Oil co. 44.5° A.P.I. 60°F. The Lima, Ohio and Bradford, Pa. crudes probably have a paraffin base while the Bartlesville, Okla. crude has an intermediate base and the Santa Fe Springs crude has a napthene base. TABLE GAS I ANALYSTS METHANE July 26, 1930 Methane 98.64 % Dec. 29, 1930 98.13 fo -------- -- - - Ethane 1.36 fo ------------ ETH.:ANE l~y 15, 1931 Methane--- -- ---------- 2,87fo Ethane --------------- 96.48 % Propane ------ - -------- 0.65 7c 1.87 fa The sand used in the measurements o:f' the diffusion o:f' methane into oil sand mixtures was practically pure quartz. The grain size in run P-6 and P-7 was approximately 20 mesh and minus 200 mesh respectively. The methane was prepared in the same way that F. P. Stapp prepared it by absorption of the ethane and heavier constituents of natural gas on charcoal. Two analyses ~how that the ethane content (Table I) was about 1.4% to 1.9%. The ethane used in run E-52 was prepared and analyzed (Table I) by the Standard Gasoline Co. at their Santa Fe Springs Laboratory, by condensing the ethane and heavier constituents from natural gas and separating the ethane by fractional distillation. Methods of Measurement The operation of the apparatus has been described by Richard D. Pomeroy (2). This operation varied only in the case of the measure- ment on the rate of diffusion of ethane. In this run the charcoal cell used for preparation of the methane was replaced by the steel cell used by Bru~e H. Sage (5) for measuring solubilities of natural gases in crude oils at high pressures. This cell was connected to the low pressure ethane supply tank and to the refill valve on the reservoir o:f' the apparatus used for measuring the rate of diffusion. The steel cell was placed in a bath of low boiling gasoline and several pounds of solid carbon dioxide added. Sufficient ethane was liquified to supply the run and the higher pressure required was obtained when the cell was warmed up to room temperature. Definition of Terms. W = weight of oil used; d =density of oil at 30°0; V = volume of oil used; P = pounds per square inch; Vi= initial volume equivalent of gas let out of reservoir gage 0 in cc. measured at 86 F and 760 mm., representing the volume of gas over the oil at the beginning of the run obtained by extrapolating the rate curve to zero time; V 8 = total amount of gas admitted to cell at time of saturation; m = slope of the experimental diffusion rate curve corrected for increase in volume of the liquid phase due to solution of gas; m' = uncorrected slope; €' = Increase in volume of liquid phase determined by using the uncorrected saturation, in cc. increase in volume of oil per cc. of gas dissolved; c = Increase in volume of liquid phase expressed in cc. increase in volume of oil per oc. of gas dissolved, using the corrected saturation value; C = solubility of the gas in a cc. of solution at the given press sure and temperature, expressed in cc. gas at 30°c and 760 mm; S = solubility of the gas in one cc. of initial oil, expressed 1n 0 cc. of gas at 30 C and 760 mm.; D = absolute diffusion, constant in square centimeters per second or in square feet per hour. Increase in Volume of Liquid Phase The method of determining and calculating this value per cc. of gas dissolved has been described by Richard D. Pomeroy (2). It is in- teresting to apply this calculation to the data reported by Mills and Heithecker (4). Bartlesville crude oil, 33.3° A.P. I. at 70°F Pressure in lbs. per aq. in Solubility in CC. Of gas per cc. of oil Percentage increase in volume cc. increase per cc. gas dissolved 200 6.9 1.49 0.00216 400 13.9 2.88 0.00208 600 21.0 4.38 0.00208 800 27.7 5.82 0.00210 1000 34.9 7.30 0.00209 I¥glewood, California crude, 21.l 0 A.P.I. at 70°F 200 5.0 1.10 0.00220 400 9.9 2.15 0.00217 600 14.9 3.23 0.00216 800 19.5 4.30 0.00220 1000 24.5 5.40 0.00221 Seminole, Okla. crude 41.4° A. P. I. at 70° F 200 10.2 1.72 0.00159 400 20.5 1.47 0.00159 600 31.2 5.20 0.00167 800 41.8 6.97 0.00167 1000 51.8 8.70 o.001ss Analysis of gas used by Mills and Heithecker, per cent Methane 76.77 Ethane 12.38 Carbondioxide o.9s Illuminants 0.90 Oxygen 0.65 Nitrogen 8.32 This shows that the increase in volume of the oil per cc. of gas dissolved is, within experimental error, a constant up to 1000 lb. per sq. in. and may be extrapolated to somewhat higher pressures without any serious error. Experimental Results The slope of the curves showing the quantity of gas absorbed -rT plotted against the gives the value of rn' which must be cor- rected for change in volume of the oil before using it in the final calculation of D. The values for the initial volume and m' were de- termined on plots 3 times as large as the experimental curves given here. In some cases it was found necessary to add or subtract ·a con- stant value before plotting the experimental data in order to retain the same scale. This can be determined easily by consulting the data table (Table II) for the values of Vi• Check runs on the rate of absorption of methane in kerosene (Fig. 1) and in cyclohexane (Fig. 2) show very good agreement for the value of m. In the case of liquid petrolateurn (Fig. 3), the runs were ma.de at different pressures and the slope of the curves have the right order of magnitude but the diffUsion constant deviates 17% from the average value. However, at such a slow rate of absorption the volumes of gas were so small that the chances for experimental error were relatively large; although actually not much greater in magnitude than in the runs where good agreement was obtained. The rate of absorp- tion of methane in the high gasoline fraction (Fig. 4) is different from the values reported by F. P. Stapp (3). It is likely that this fraction was given fUrther treatment after being used in earlier runs and no longer had quite the same composition. The rate of absorption of methane in pure he:ir..2.ne (Fig. 5) was determined to fill in the hom0- TABLE II EXPERI MENTAL RESULTS at 30°C. with ],!ethane ( Ethane in E-52) Run Density w gm. 30°c 0 .A.P.I. P lb./ 60°F. sq. in. m' m V· 0. 79 63 43.8 300 4.84 5 . 03 811 .2 60~90 0 ,7 963 &3. 8 300 4 . 88 5.07 978 .2 High Gasoline 35.18 Fraction Cyclohexane 70.7 5 0 .77 2 45.3 350 7.84 8 .28 742.4 0 .7 689 49.8 249 7,117 7.373 474 . 8 68 .84 0 .7689 49.8 249 7.113 7.369 446.0 Liquid 71.32 Petrol at eum II 71.64 0 .8771 29 .4 250 1.62 1.70 789.1 0 .8771 29 .4 302 .5 1 .16 1.21 672 . 8 50 IsopentR.ne 28.69 0 .61 02 95.l 192.5 374.5 51 Hexane 35 .8 2 0 .6 53 81 . 8 298.5 D calc. for each po int 14.30 15 .09 E-52 Cyclohexane with Ethane C-2 Lima, Ohio 37.61 0 .7689 49.8 249 37.8 40.0 1 28 70. 07 0 . 822 38 . 4 29 8 . 5 3 .78 3 . 94 565 .7 76.41 Santa Fe Springs, Cal. Bartlesville, 73.85 Okla. Bradford,Pa. 69 . 09 0 .8 50 33 .0 298 . 5 3 . 65 3. 82 549 .9 0 . 852 32.6 29 8 ,5 3.03 3 .16 571.4 0 .7 93 44 . 5 298 .5 5 .48 5 .75 735,5 P- 6 Heptane 22.13 Fraction 20 mesh sand 130 .3 38 .8% porosity P-7 Sarne oil 22 . 98 -2 00 mesh sandl 06 .6 44 . 6fc porosity o. 7 09 5 64.4 350 . 4.26 4.50 700.0 64.4 350 4.99 5 .28 943 .4 No. .1 0 l.- 41 Kerosene 62 .34 43 11 44 45 46 47 C-3 C-4 C-5 11 Cross- Se.ci/an Area in lfl/ns 176. 5 2. 644 0 .7 095 2. 644 cxf Cell 30, 5/-' 5'.Z :::. 9, '1.203 cm."- = 9, 876'8 " TABLE II (continued) Run No. Vs Vs -Vj Length of run hours 41 1607.2 796.0 30.2 0.00183 - 17 60. 7 782.5 35.8 32 . 0 4'' ,) 44 = Cs s D x 10 5 0.00179 10.52 10.72 3.02 o. 00183 0.00179 10 . 59 10.79 3.07 0 . 00224 o. 00218 11.31 4.85 (Run 30) 45 32.0 0.00197 0. 00191 - - 5.08 46 1502.6 1056.6 27 . o 0.00197 0 . 00191 B .• <ila 12.21 5.08 47 1416.3 627.2 16.5 0. 0019 0.0018 7,96 8. 01 0.62 48 1209. 0 536.2 107. 6 0.0019 0.001s : 6, 76 6 . 85 0.43 50 880 ,8 505 .8 104,5 0. 00278 0.00270 10.50 11.15 14.00 51 1127 .4 9 50 . 9 12.5 0 . 00266 0 . 00250 17.54 18.34 9.93 E-52 2484.5 2356.5 70.4 at 197 lb. C-2 1336.9 771.2 34.0 0.00367 0.00355 52.6 64. 6 7,75 at 249 lb. 0,0020 0.0019 9 . 27 9.44 2.40 C-3 1320.9 771.l 30.6 0.00218 0.00210 8.83 9.00 2.49 C-4 1286. 0 714 . 6 • 32 . 2 0.00190 0.00180 8.45 8 . 85 1.86 C-5 1662,8 927 . 3 0. 00224 0.00218 10.88 11.15 3.72 29.8 P-6 33.0 0.00237 8.25 5.37 P-7 31.5 0.00237 8 .25 5.58 logus paraffin series as much as possible. The rate of diffusion of methane into isopentane (Fig. 6) was measured and the run carried out to nearly complete saturation requiri:ng 105 hours. The agreement of this run with the theoretical equa- tions is given by Richard D. Pomeroy and is very good. It shows how the rate deviates from the square root of the time relation after 50% saturation. However, the deviation does not become marked for practical purposes until after so% saturation when the logarithmic rate begins to have an appreciable effect. The increasing time in the latter part of the rt1n shows that a run giving such a high degree of saturation with an oil into which methane diffuses slowly, would require several weeks. The rate of absorption of ethane by cyclohe xane {Fig. 7) was measured at the same pressure and temperature as the rate of absorption of methane in the same oil. It was found (Fig. 12) that it required about 5½ times longer for a given quantity of methane to diffuse into cyclohexane as for the same quantity of ethane to diffuse under the sane conditions into the same oil. In this- run, a s lug was supported in the top of the cell to reduce the total volume of the system. The 2 points on the curve following the square root of the time in minutes equal to 60 are off the curve, because the volume of the liquid phase had increased so much that the surface of the liquid reached the bottom of the slug and the surface area for gas to diffuse into was reduced to a small fraction of its value earlier in the run. Due to this difficulty, the saturation value was determined at 197 lb. per s q. in. gauge, in order that the final volume of the liqui d would not be greater than the total volume of the absorption cell. The saturation value at 249 lb. per sq. in. was calculated by assuming the solubility directly proportional to pressure which is a reasonable assumption since all data on natural gas solubilities show that this is true at these low pres- :.D;;_orp si,, .,3•.;f'!QJ1. \J o,; ;-," : ..u. te :. . u. ~ at ~6 °~•' i n I 3c~ ... n :..or. e re. t-Lc,n '!. ': . nd , ........- --+--- - ·- ~ - IO ~30 yr""''"';!"'.---.-...- 40 so 70 so sures. This value was found to be about 4~ times as great as the solu- bility of methane in this oil. Since the diffusion constant is the ra- tio of the squares of m and C8 , the diffusioh constant is greater than for .methane. The line obtained is not quite straight below 50% satura- tion because the partial pressure of ethane '1 s not constant, but decreasing due to the increasing concentration of methane in the gas over the oil. This increasing concentration is due to the fact that a con- stant ratio of ethane to methane is admitted to the cell at each reading, while . the rate of solution of ethane is 5½ times as great as for the methane. · This concentration of methane is probably 2 or 3 times as great at 50;t saturatio~ as at the beginning of the run; therefore, the curve should not be a straight line in the first half of the run, becaus~ the partial pressure of ethane is decreasing. J Measurements of the rate of diffusion of methane into the crudes at 30°0 and 29a½ lb. per sq. in. gauge (Fig. 8) shows that the same re- lation holds for a mixture of petroleum hydrocarbons as for a single hydrocarbon. The variation in the rate between the different crudes seems to have no relation to the crude base, because the Lima, Ohio and Santa Fe Springs crude have practically the same rate, while the ex.ample of a mid-continent crude is lower and another paraffin crude, Bradford, Pa., shows a higher rate. No definite conclusions can be drawn from such a small number of examples other than that the rate of diffusion of methane into crudes has the same order of magnitude as the rate of diffusion into purified oils with the same density and origin. The rate of diffusion of methane was made with one oil using 2 porosities and 2 grain sizes (Fig. 9). The variation in grain size from 20 to 200 mesh apparently has little effect on the rate. Since the rate of diffusion into a unit surface of oil is less when the oil is in a sand than when it is not, as shown by the smaller diffusion constant (reduced from s.20 to 5.37 in P-6 and to 5.58 in P-7), there is some relation between porosity and the diffusion constant. Conclusions It is interesting for the pu~ose of comparison to plot all the rates of diffusion on the same scale for a 100 ii. per sq. in. pressure differential (Fig. 10). This has been d~ne on the curves showing the rate of diffusion in ou. ft. per sq •. ft. per 100 !b. pressure differential against the square root of the time in hours. It is to be observed on the plot that the rate is 32 times as fast for isopentane as for the liquid petrolateum. This is the maximum variation of rates studied. In the paraffin series the rate of diffusion of methane decreases as the number of carbon atoms increases. The solubilities show also that the total amount of gas that will be dissolved is less in the heavier liquids ( Table III). On another curve (Fig. 11) the rate of absorption of methane by the crudes is illustrated on t h e ~ basis. It is ob- served that the low A.P.I. gravity crudes, that are usually found in depleted fielis, will ~equire a longer time for diffusion of the same quantity of gas into the oil. The rate of diffusion of methane into a sand filled with oil is shown to be less (Feg. lf) than into the oil, even if the cross-section area is corrected for the presence of the sand. This is shown with 2 porosities by the heptane sand runs and with one porosity by the high gasoline fraction fraction sand. The best explanation is that the gas must travel in a horizontal as well as in a vertical direction in diffusing through the oil and sand. The rate measurem:3nt on the oil was made under such conditions that the diffusion took place Ab orption Ra s Uethane 1n Prepared Liquids ,... r - -- - - ' - - -- - - - t - - -- ---'1-- -V ~ 0 ...,., Q) ► " ~ " ~-.__ __t-__7 "!-~~~---t---:-::.~~-t- - --t- - --1-----+--- - -l ,., ,<\-4 tl'""~-----:~i'Jir-~,,,C-t-----+-----;------+- - --+-------4--- -- -J ::, u JTine in hours \ only in a vertical direction. When the sand is present, the gas mst travel in a horizontal direction to get around the sand grains. There- fore, if the rate of diffusion through the oil is the same, it should require a longer time for the gas to diffuse through the surface of a unit area of oil when the sand is present than when it is not. Vlhen the temperature of the oil and gas is increased, the run with the high gasoline i raction at 3o 0c and 45°c: shows that the rate of diffusion is higher at t~e higher temperature (Fig. 13}. • The 1~ crease in this case is over 25%. However, no quantitative conclusions can be drawn from a single run, except as to order of magnitude. In order to illustrate the time required to repressure a formation, a plot (Fig. 1.§) has been ma.de with the crudes and oil sands. of the time required to 50% saturate a liquid, or sand full of oil, 10 ft. deep' with methane at 3o 0c and 100 lb. per sq. in. differential pressure with gas diff'using through one surface of the oil. shows that this requires a comparatively long time. The chart The plot of Santa Fe Springs crude sand has been made assuming the same percentage reduction in the diffusion constant for the same porosity as in the case of the prepared liquids. This shows that it requires longer to 50% saturate a given depth of oil sand than it does to saturate the same depth of oil. These comparatively long times required for the diffusional process are an important consideration in repressuring oil sands and also in the storing of gas in formations of known limited extent. The plot of the diffusion constants against A.P.I. gravity is interesting (Fig. 16). It looks as if a straight line might be drawn through these points. However, if this is done, the diffusion constant becomes zero at about an A.P.I. gravity of 25° which is false, because Absorpti !.!ethane i. Rates at fferent Ten ern turus n Gasoline 'racti on, 4 4°A P I t "'l:l ... ..8. .. o' .Q 8 ~ ,.:l:I ~ II) .., ~ O' II> ';,- " ....., hJ) . ::, 0 2 J 4 6 T'me in Hours Fiq. 13 8 10 12 Times Required for Half Saturation of 10 foot depth of liquid w1 th Methane Gas Calculated for Santa Fe Springs Crude, 5 10 20 15 Time 1n Years Fi 9 . 15 2 30 36 • • lleDne Fraction ... Ill Hexane 1 "·---- - C ~ Ia ction (23 ~ IO I I i1 I. I 60 . Degrees A P! I 255-P- at -a press) 90 there would be some diffusion; although, it would be small. Therefore, the lowet part of the curve should not be a straight line but should slowly approach zero, never quite reaching it. One reason these points tend to give a straight line is the fact that a majority of them are for paraffins for which the constant would be very small at low A.P.I. gravities, because the oils are solid at 30°c. However, benzene lies far above the other points showing that the class of compounds has a large influence on the rate, and such a curve could not be applied in general for all types of crudes. It might, however, be applied to de- terminations of the diffusion constants on oils from a single district having the same base. The fact that the two paraffin crudes lie near a line drawn through the paraffin compounds plotted, substantiates this conclusion. Furthermore, the napthene base crude lies off the line as would be expected. However, it must be pointed out that this is only for diffusion of methane at 3o 0 c and cannot be used for a mixture of gases or at other temperatures. It is likely that some other factor, or factors, which are indirectly related to the density of the ~yd.re-carbon liquid is the variable that effects the diffusion constant most profoundly, because this plot only shows a g-eneral trend of values and not a smooth curve. Table III is a tabulation of the results obtained by Stapp, Pomeroy, and the writer. Acknowledp;ements This research has been carried on for the American Petroleum Institute as part of Project No. 37 with funds contributed by Mr. John D. ~ockefeller and the Universal Oil Products Company. The as- sistance of Dr. William N. Lacey as director of the research is greatly appreciated hy the writer; also Mr. Richard~. Pomeroy and Mr. Bruce H. Sage for assistance with the apparatus, in taking readings, and in assembling data; also the Standard Gasoline Co. for cooperating in supplying gas samples at high pressures and in preparing the ethane sample. References (1) Nathan F. Scudder; Annual Report 1927-28 to the American Petr0leum Institus•. (2) Richard D. Pomeroy, Ph.D. Thesis O.I.T. 1931 (3) Frederick P. Stapp, M. S. Thesis C.1.T. 1930 (4) R. Van A. Mills and R. E. Heithecker, u. s. Bureau of Mines, Serial No. 2893, Oct. 1928 (5) Bruce H. Sage, M. s. Thesis c.I.T. 1931 TABI.E III SUMMARY OF RUNS by Stapp, Pomeroy, and Hill with Methane at 30 ° c. Averagg ~ Oil 28a High Gasoline Fraction '# l 28b ciiil /100 lb. Accepted C6 /100 lb. D X 105 4.98 19.3 4.85 18.80 8.30 31.78 4.97 4.18 4.13 " 4.15 5.00 29 II 4.09 4.98 30 Same# 2 34 Heptane Fraction 7.69 35 " 8.31 36 " 37a II 6.56 37b " 8.58 3'lc " 8.20 3.94 5.21 c.g.s. 5 D x 10 in Eng. units D x 10 5.21 8.26 4.08 6.40 24.82 19 High Gasoline Fraction# 1 0 at 45 C. I so-octane 4.84 7.37 28.5 21 Kero Fraction 3.24 3 .19 12.35 24 Hexane Fraction 10.10 39 .10 9.93 38.J 6. 05 23.38 3.06 11.90 23 25 " 26 II 27 " 51 Hexane 32 Benzene 10.45 6.22 6.13 9.97 9.51 6.05 5.88 6.02 3.63 6.58 33 41 11 Kerosene 6. 07 3.53 3.02 3. 57 • 3.52 43 11 3.53 3.07 TABLE ~ Oil 45 Cyclohexane 46 " 47 Cs /100 lb. Liquid Pet rolat eum III (continued) Accepted C8 /100 lb. D X 10 5 Average D x 10 5 c.g.s. • D x ·10 5 in Eng. units 5.08 2.27 4.78 5.08 5. 08 19. 65 2.25 0.62 0.52 1.97 48 II 50 Isopentane 5.65 14.00 54.23 E-52 Cyclohexane with Ejhane at 30°c. 21.12 7.75 30.0 C-2 Lima, Ohio 3.11 2.40 ~-~~Q C-3 Santa Fe Springs, Cal. Bartlesville, Okla. Bradford, Pa. 2.91 2.49 9. 94 2.83 1.86 ?.?:!, 3.64 3.72 14.40 3.94 2.76 10.70 5.21 5.37 20.78 5.21 5.58 21.58 C-4 C-5 P-31 High Gasoline Fraction #2 20 mesh sand 34.2% porosity P-6 Heptane Fraction 20 mesh sand 38.8fo porosity P-7 Same oil -200 mesh sand 44.6% porosity 0.42 2.23 TABLE ~ Oil or Oil Sand III (continued) Time in Years to 50 %Saturate a 10 ft. Layer with Methane at 30°c and 100 lb./sqt in. pressure differential. C-2 Lima, Ohio 24.l C-3 Santa Fe Springs, Cal. 23.3 C-4 Bartlesville, Okla. 31.l C-5 Bradford, Pa. 15.5 ?-31 High Gasoline Fraction# 2 20 mesh sand, 31.2% porosity 21.0 P-6 Heptane Fraction 38 .8 % porosity 20 mesh sand Same oil -200 mesh sand, 44.6% porosity 10.78 P-7 Assumed crude sand with Santa Fe Springs Srude 10.36 33.38