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By H. H. Kaveler, W. R. Evans, Jack Tarner

The geological features, development history and engineering detail of the Shuler Field and the results of approximately two years of unitized operation of the Shuler Jones Sand Pool, were discussed in a prior publication.' The purpose of this paper is to present the results of pressure maintenance in the Shuler Jones Sand Pool after nine years of unit operation. GENERAL INFORMATION The Shuler Jones Sand Pool is located in and about Section 18, Township 18 South, Range 17 West, Union County, Ark. The pool was discovered .in September, 1937, unitized in February, 1941, and subjected to gas injection operations in July, 1941. Water was first returned to the reservoir in July, 1944. The reservoir is an anticlinal trap covering about 4,000 acres. The 154,000 acre-ft of sandstone initially consisted of approximately 150,000 acre-ft of productive oil zone and 4,000 acre-ft of gas-cap. The average depth of production is 7,400 ft. Maximum closure of the reservoir is 135 ft and the oil column lies between a gas-oil contact at -7,270 ft and a water-oil contact at -7,370 to -7,380 ft. The field is approximately four miles long. east and .west, and one and one-half miles wide. The sand grains are angular and vary from fine to medium size. The porosity of the sandstone averages 20.2 per cent. The specific permeability averages 400 md. Some zones have as high as 30 per cent porosity and specific permeability of 4,000 md. The reservoir rock is not uniform in character but consists of sandstone zones interspersed with shale. The variation in rock characteristics is evident in the electric log and core analyses presented in the original publication. Asphalt present in the pore space of the sandstone limited the reservoir to the southeast and apparently blocked any encroachment of water from that direction. The initial reservoir pressure at a subsea depth of 7,300 ft was 3,520 psi. The reservoir temperature was 198ºF. Initially, the solution gas volume was 765 cu ft per bbl and the reservoir volume factor was 1.45. The gas solubility and formation-volume-factors of the reservoir liquid are related with reservoir pressures above 300 psi as follows: Solution gas, cu ft per cu ft, S = 0.0334 P + 18.65 Formation volume factor of reservoir oil, FVF = 8.0 x 10 -5 P + 1.168 Gas volume factor, standard cu ft of gas equivalent to one cu ft of gas at reservoir conditions of temperature and pressure, F = .062 P - 4 Pressure (P) measured in psia. The equation for the gas volume factor presented above is based on a direct measurement of a sample of the gas and is a correction of that used in the original paper. The gravity of the oil produced is from 32 to 34" API. CALCULATION OF INITIAL OIL IN PLACE The Jones Sand production history is interesting because it lends itself to analysis by material balance. Production statistics from discovery of the Jones Sand through 1949 and material balance calculations of the initial stock tank oil in place are shown in Table I. The usual procedure in testing the application of material balance calculations is to compute the apparent initial volume of oil in place, using production and pressure information obtained at different time periods. If the apparent oil in place volumes computed increase with successive time periods, water encroachment is indicated and approximations must be mads to correct for its influence. The first requirement in utilizing such calculations is reliable reservoir pressure, accumulated gas, oil and water production, and PVT data. Calculations of apparent oil in place in the Jones Pool, based on field data

Jan 1, 1951

By W. R. Evans, H. H. Kaveler, Jack Tarner

The geological features, development history and engineering detail of the Shuler Field and the results of approximately two years of unitized operation of the Shuler Jones Sand Pool, were discussed in a prior publication.' The purpose of this paper is to present the results of pressure maintenance in the Shuler Jones Sand Pool after nine years of unit operation. GENERAL INFORMATION The Shuler Jones Sand Pool is located in and about Section 18, Township 18 South, Range 17 West, Union County, Ark. The pool was discovered .in September, 1937, unitized in February, 1941, and subjected to gas injection operations in July, 1941. Water was first returned to the reservoir in July, 1944. The reservoir is an anticlinal trap covering about 4,000 acres. The 154,000 acre-ft of sandstone initially consisted of approximately 150,000 acre-ft of productive oil zone and 4,000 acre-ft of gas-cap. The average depth of production is 7,400 ft. Maximum closure of the reservoir is 135 ft and the oil column lies between a gas-oil contact at -7,270 ft and a water-oil contact at -7,370 to -7,380 ft. The field is approximately four miles long. east and .west, and one and one-half miles wide. The sand grains are angular and vary from fine to medium size. The porosity of the sandstone averages 20.2 per cent. The specific permeability averages 400 md. Some zones have as high as 30 per cent porosity and specific permeability of 4,000 md. The reservoir rock is not uniform in character but consists of sandstone zones interspersed with shale. The variation in rock characteristics is evident in the electric log and core analyses presented in the original publication. Asphalt present in the pore space of the sandstone limited the reservoir to the southeast and apparently blocked any encroachment of water from that direction. The initial reservoir pressure at a subsea depth of 7,300 ft was 3,520 psi. The reservoir temperature was 198ºF. Initially, the solution gas volume was 765 cu ft per bbl and the reservoir volume factor was 1.45. The gas solubility and formation-volume-factors of the reservoir liquid are related with reservoir pressures above 300 psi as follows: Solution gas, cu ft per cu ft, S = 0.0334 P + 18.65 Formation volume factor of reservoir oil, FVF = 8.0 x 10 -5 P + 1.168 Gas volume factor, standard cu ft of gas equivalent to one cu ft of gas at reservoir conditions of temperature and pressure, F = .062 P - 4 Pressure (P) measured in psia. The equation for the gas volume factor presented above is based on a direct measurement of a sample of the gas and is a correction of that used in the original paper. The gravity of the oil produced is from 32 to 34" API. CALCULATION OF INITIAL OIL IN PLACE The Jones Sand production history is interesting because it lends itself to analysis by material balance. Production statistics from discovery of the Jones Sand through 1949 and material balance calculations of the initial stock tank oil in place are shown in Table I. The usual procedure in testing the application of material balance calculations is to compute the apparent initial volume of oil in place, using production and pressure information obtained at different time periods. If the apparent oil in place volumes computed increase with successive time periods, water encroachment is indicated and approximations must be mads to correct for its influence. The first requirement in utilizing such calculations is reliable reservoir pressure, accumulated gas, oil and water production, and PVT data. Calculations of apparent oil in place in the Jones Pool, based on field data

Jan 1, 1951

Trans No. Place Date Vol. 1. Wilkes-Barre, Pa. May, '71 1 2. Bethlehem, Pa. Aug., '71 1 3. Troy, N. Nov., '71 1 4. Philadelphia, Pa. Feb., '72.. 1 5. New York, N. Y. May, '72 1 6. Pittsburgh, Pa. Oct., '72 1 7. Boston, Mass. Feb., '73 1 8. Philadelphia, Pa. May, '73 2 9. Easton, Pa. Oct., '73 2 10. New York N. Y. Feb., '74 2 11. St. Louis, Mo. May, '74 3 12. Hazleton, Pa. Oct., '74.. 3 13. New Haven, Conn. Feb., '75 3 14. Dover, N. J. May, '75 4 15. Cleveland, Ohio Oct., '75 4 16. Washington, D. C. Feb., '76 4 17. Philadelphia, Pa. June, '76 5 18. Philadelphia, Pa. Oct., '76 5

Jan 1, 1934

By S. R. B. Cooke, H. S. Choi, D. H. Harraway, I. Iwasaki

The mineralogy of natural iron ore samples and their slimes have been investigated and the nature of slime interference in iron ore flotation has been studied. The results have been correlated with the flotation behavior of a natural ore sample. Various conclusions have been reached as a result of these studies. In the flotation of iron oxide ores, desliming is generally considered to be an essential step to successful separation, irrespective of whether the iron oxide or siliceous gangue minerals are to be floated, although some workers have found empirically that certain collectors and reagent combinations are less sensitive to the presence of slime than others. The detrimental effect of slime is considered to be twofold. First, the presence of slime presupposes a high reagent consumption because of high specific surface. When clays are present and when cationic collectors are used abstraction by ionic exchange may augment this condition. Attempts to compensate by the addition of large amounts of reagent result in only partial correction. Second, slime coatings on granular particles tend to interfere with the bubble-mineral contact. The nature of slime coatings in flotation is quite complex and has been the subject of considerable study; an attempt was recently made by Fuerstenau et al.' to relate the slime-coating density with flotation recovery and with the properties of the electrical double layer at the mineral surfaces. Although major constituent minerals in the oxidized iron ores of the Mesabi and Cuyuna ranges are hematite and goethite (limonite) as the iron oxides, and quartz and chert as the siliceous gangue, very little is known of the mineralogy and of the chemical and physical characteristics of the slimes, and still less of the interaction between slimes, collector, and the mineral surfaces. For pragmatic reasons iron ore slimes are defined as — 20p material, based upon the calculated settling velocity of a quartz sphere of the stated diameter, and of all other equal-settling mineral particles. Active slime interference with flotation is usually attributed to particles 5p in size or finer, the extent of such interference appearing to depend not only on the mineralogy but also on the size distribution of each mineral in the slime fraction. The objective of this work was to acquire a more specific knowledge of the constitution of iron ore slimes and of their role in flotation. The mineralogi-cal composition of natural slimes was obtained by differential thernal analysis (hereinafter referred to as DTA), electron microscopy, and chemical and X-ray analyses. Some flotation tests were made on natural ore samples. The surface properties of several constituent minerals were investigated by electrophoretic measurements and by determination of the adsorption of some typical flotation collectors. Finally, simplified flotation tests were made on granular goethite and quartz in the presence of various artifically prepared slimes; the results were compared with laboratory flotation tests made on natural ores. MATERIAL AND METHODS Mineralogy of Some Iron Ore Slimes: Samples of two wash-ore tailing::, hereinafter identified as A* and B, *Sample A of the present investigation 18 the same am ore A in ref. 3. of a wash ore C, and of a paint rock D, all from the Mesabi range, were selected for investigation on the basis of prior information concerning their flotation behavior. The two wash-ore tailings, when deslimed, were known to respond well to flotation, whereas the wash ore was high in goethite, tended to be slimy, and responded poorly to flotation. The paint rock also exhibited sliming tendencies, and was suspected to contain relatively large quantities of clay minerals because of its high A1203 content. Gruner states that the paint rock of the Mesabi frequently contains kaolinite. To ascertain the relative sliming tendencies of each sample a standardized desliming method was employed. All samples were ground through 65 mesh using jaw and rolls crushers. A 500-g sample of each

Jan 1, 1962

By T. M. Morris

THE rate of flotation of solid particles determines the percentage recovery of these particles which can be obtained during a given time interval. It is an established fact that the recovery is greatest in the fine sand size range and falls off on either side of this size range. It is also a fact that the history of the development of concentrating devices has been marked by a desire to recover the small particles: tables were developed to treat material too fine to recover in jigs; flotation recovers material too fine to be recovered on tables. As our ores become more complex and require finer grinding, a greater proportion is in the slow-floating size range. It is therefore of economic importance that the effect of size of particle upon rate of flotation be studied. Many studies have been made along this line. The present investigation attempts to quantify the rate of flotation by means of a rate equation, and then compares the effect of size upon the rate of flotation. It was found that the flotation rate constant increases with increase in diameter of particle in the size range smaller than the optimum size particle. The flotation rate constant decreases with an increase in diameter of particle in the size range coarser than the optimum size particle. This suggested two different actions taking place, and these are discussed. Suggestions for further work in order to improve the flotation rate of both fine and coarse particles are made. The usual method of expressing rate is to plot cumulative percent recovery vs time. If we knew the equation of this kind of curve we could replot it as a straight line, and the slope of the line would be an index of the magnitude of the flotation rate. It is easier to compare straight lines than curves. The basis used for obtaining the equation of the recovery vs time curve is the law of mass action. This law states that the "rate of a chemical reaction is proportional to the `active masses' of the reacting substances present at any given time." This, of course, implies a constant temperature. We can modify this for our use by using the term flotation reaction instead of chemical reaction and the term floatable particle instead of active masses. [ ] where C denotes concentration of particles, t denotes time, k denotes a proportionality constant. If the exponent of C is 1, then we have a first order rate reaction. If the exponent of C is 2, then we have a second order rate reaction. For a first order rate reaction, we obtain, after integration, [ ] where k is again a proportionality constant and has the dimension of the reciprocal of time. C, is the original concentration or weight or percentage of floatable particles. C, is the concentration or weight or percentage of floatable particles remaining in the flotation cell after time t. If all particles of the mineral to be floated were capable of floating we could take C, as 100 and C, would be 100 - R, where R is the cumulative percentage recovery of mineral at time t. But it is not usual for all of the particles to be capable of floating, because of surface oxidation, etc. Therefore, we must introduce a factor x which is the percentage of unfloatable mineral. Hence the first order equation is [ ] It has been proposed by various workers1-3 that this equation describes the flotation rate. More recently N. Arbiter4 states that a second order rate equation fits the recovery vs time curve more closely than does a first order rate equation. Morris' has discussed the evidence presented for this statement. It has been concluded that the first

Jan 1, 1952

By W. S. Hyler, W. L. Bruckart

The powder metallurgy and arc-cast types of wrought molybdenum stock were studied in rotating beam fatigue. Endurance ratios of unnotched specimens after 5x10 cycles were found to be 0.74 and 0.81, respectively. Fatigue notch factors (K,) of 1.36 and 2.05, respectively, were obtained on V-notched specimens having a theoretical stress-concentration factor Kt = 3.1. MOLYBDENUM and its alloys are rapidly gaining importance as engineering materials of construction for high temperature applications. AS a wrought material, molybdenum and its alloys are outstanding above 1800°F. It is necessary, however, with molybdenum to provide elevated temperature oxidation protection. This is currently being studied by a number of investigators. Thus far, there have been no published data on the fatigue behavior of molybdenum either at room temperature or at elevated temperature. The knowledge of fatigue behavior, particularly notched fatigue behavior, becomes increasingly important as the engineering importance of a material increases, especially from the design standpoint. The work described here was directed toward determination of the notched and unnotched rotating beam fatigue characteristics of molybdenum at room temperature. Also, it was desired to learn whether any difference exists between wrought molybdenum of the powder metallurgy and the are-cast types. Fabrication History of Bar Stock For this work, bar stock was procured from Climax Molybdenum Co. (are-cast type) and from Westing-house Electric Corp. (powder metallurgy type). The processing histories of these materials are listed in Table I. The first lot of are-cast molybdenum was deoxidized by aluminum additions. The second lot was deoxidized by carbon." Both lots of the powder Microstructure A microscopic examination of these materials, as received, revealed the powder metallurgy molybdenum to be free of inclusions and to be finely fibered. On the other hand, the are-cast C molybdenum possessed numerous carbide inclusions, and the arc-cast A appeared to have coarse grained fibers. These are shown in Fig. 1. Owing to the large apparent difference in fineness of fiber between the are-cast A and the powder product and are-cast C, a check was made of the recrystallized grain sizes to determine whether these differences persisted. A series of recrystallization anneals revealed mixed grain sizes in both the are-cast A and the powder product. Variations in grain diameter of as much as 50 times were found after full recrystallization at 1200°C for 30 min. There was no distinction between the two. Arc-cast C was not checked. Room Temperature Mechanical Properties Prior to subjecting the materials to fatigue tests, room temperature mechanical properties were determined. These data, together with the tensil: strength of the notched bars, data,togetherare listed in Table tensil: There were no significant differences in the tensile strengths of the two types of molybdenum. However, the powder metallurgy material was generally more ductile and yielded at a somewhat lower stress than the arc-cast material. Tensile strengths of the notched specimens indicated a slightly greater notch strengthening effect in the are-cast C than in the powder product, lot 2. Room Temperature Fatigue Properties Sample Preparation: Specimens were prepared for use in R. R. Moore rotating beam fatigue machines. These specimens had a continuous radius test section with a minimum diameter of 0.260 in. The specimens were prepared by grinding to shape and polishing to produce a smooth unworked surface. Polishing consisted of rotating a disk in the continuous radius section on which were attached, successively, emery belts of 240, 400, and 600 grit. The specimens were slowly rotated during the operation. The belt speed was high, and rotation was such that polishing scratches were longitudinal. Unnotched Fatigue Properties: Unnotched fatigue data were obtained from a number of specimens of each of the four lots of molybdenum. The results of the tests are presented in Fig. 2. From this figure,

Jan 1, 1956

By Paul B. Crawford, Melvin B. Burton

A procedure is given which describes how the gelatin model may be-used to study the effect of mobility ratio on areas swept before and after breakthrough in fluid injection programs. Differences in mobility ratio are achieved through the proper selection of electrolytes for the invading and displaced fluids. The progress of the front is followed visually and photographed or traced onto plates (it desirrd positions before and after breakthrough. Example applications to standard flooding pattrrrls, vertically and horizontally fractured reservoirs and the in-situ combustion recovery process ore presentrtl. INTRODUCTION In water flooding, gas cycling and other fluid injection programs, the sweep efficiencies and swept areas after breakthrough are known to depend on the mobility ratio. Previous investigators have described the application of the X-ray technique, stepwise use of the poten-tiometric model and numerical procedures for studying these problems.1,3,4,6 Others have described the application of the electrolytic and gelatin models for studying sweep efficiencies at a mobility ratio near one.2,5,7,8,9 It is a purpose of this paper to describe a procedure for using the gelatin model to study swept areas at mobility ratios other than one. PROCEDURE The technique developed for gelatin model studies is composed of four phases: the construction of the model, the selection and preparation of electrolytes, the running procedure, and the recording of the swept areas. Each phase is discussed independently in order that the over-all procedure will not be confused. Construction of the Model Since some of the advantages of the gelatin model are its economy, and speed, it is desirable to have as small a model as is possihle without creating error through the inability to follow visually the progress of the colored front. For this work, it was found that a distance of 4 to 6 cm between salt bridges is convenient to use. Since the size is relatively small, it follows that the gelatin layer must be thin. For this study, 1/8 in. was used as the gelatin thickness in each case. The model was constructed on a flat 1/2-in. plastic (Lucite) base with boundaries constructed from 1/8-in. plastic strips. The well pattern to be studied was outlined with the 1/8-in. plastic strips on the base with narrow apertures (- - 2 mm) in the boundary to represent the wells. Behind each well opening, a rectangular area of some 8 to 12 sq cm was outlined by additional plastic strips. The plastic strips were fastened to the base by any suitable non-conducting cement so that the boundary system was liquid tight. The electrodes were constructed from sheet copper in a fashion that would allow easy removal. In this work, it was found that by simply forming a large U-shaped clip from a strip of the copper that would slip over the boundary was satisfactory and easily removed. The electrodes should be as wide as one of the sides of the rectangular area behind the well opening. If a fractured pattern is studied, fractures inside the well pattern may be represented by strips of copper of the desired shape mounted in some easily removable fashion. The reason that apertures (or salt bridges) were used for wells instead of metallic electrodes is that the plating of the electroactive ion at the cathode and the introduction of an electroactive ion at the anode has a detrimental effect on the swept area outline if these operations \rere permitted to be carried on within the well pattern itself. The anode may be used within the well pattern

Jan 1, 1957

By A. F. Witt, A. M. Gaudin, A. K. Biswas

Finite contact angles in the rutile-water-organic liquid system are traceable to contamination or are due to addition of a surface-active agent. Finite contact angles are invariably accompanied by hysteresis.1-7 Besides surfactant concentration and pH, the nature of the organic liquid is found to be a factor influencing the magnitude of contact angle hysteresis. In a recent paper the authors have reviewed principles and applications of measurement methods for contact angles and their hysteresis.22 In this paper, these methods are applied to a system consisting of rutile, an organic liquid (benzene, decane, or dode-cane) and water. Surfactant (dodecylamine hydro-chloride) was used at various concentrations and various pH values. MATERIALS A synthetic rutile crystal supplied by the Linde Co. was used. It is a cylinder 1/2 in. diam, with faces cut perpendicular to the c-axis. The crystal is stated to be alumina-free and to be 99.9% pure. Rutile is a high surface energy solid, its calculated average field strength being 2.7 x 105 e.s.u.,9 its dielectric constant10 is 114. The zero point of charge of rutile was measured11 and found to be at pH 6.0. The atomic distances and bond angles of the tetragonal crystal of rutile have been precisely determined.l2 The organic liquids were specially purified. Reagent grade benzene was repeatedly shaken with concentrated sulfuric acid to remove thiophene, then neutralized with sodium hydroxide solution, rinsed with distilled water, dried overnight over anhydrous calcium chloride and filtered. The refractive index of this chemically purified benzene was 1.4977 (at 25°C) - very close to that of pure benzene (n25 1.4979).13 Both n-decane and n-dodecane were washed with aqueous sodium hydroxide, concentrated sulfuric acid (repeatedly, until the acid layer was colorless) and again with alkali, to free the organic hydrocarbon from fatty acids and unsaturated hydrocarbons. The organic phases were subsequently washed with distilled water and dried over anhydrous sodium sulfate. The filtered hydrocarbons were then distilled under vacuum (9-10 mm pressure). Decane, thus purified, showed traces of unsaturated and of carboxylic compounds. On gas chromatographic analysis the purified n-dodecane showed the presence of two impurities. However, the relative retention times of these components did not change substantially when measured on a polar or a nonpolar column. This indicates that the compounds were probably in the same polarity class, i.e. the components were nonpolar like dodecane. Conductivity water has always been one of the liquids. Conductivity of the water used was 10-6 ohm-' cm". Dodecyl ammonium chloride was prepared from pure amine (supplied by Armour and Co., Chicago), by Li in the MIT Mineral Engineering Laboratory.14 The critical micelle concentration at 25°C is known, 0.0138 mol per liter15 or 3.06 gpl. All our experiments have been done at concentrations lower than the critical micelle concentration. The glass vessels, glass drop holder and the rutile crystal were all cleaned with hot chromic acid followed by distilled water, concentrated hydrochloric acid, and again distilled water, and conductivity water. During the experiments, a nitrogen atmosphere was maintained. For this purpose, commercially purified nitrogen was further purified by passing it over hot copper wire at 450°C, then through columns of acidic chromous chloride solution, concentrated alkali solution and distilled water. APPARATUS AND METHODS Hysteresis was produced by the "captive drop" or constant volume drop method as well as by the "expanding-contracting drop" or variable volume drop method. The image of the drop while it is expanding, contracting or moving is projected on a screen and photographed. The developed film is projected through an enlarger and the contact angles measured with a protractor.

Jan 1, 1964

By H. D. Outmans

The mechanics of filtration are described by a theoretical-empirical nonlinear diffusion equation which, under certain circumstances, may,be linearized and then solved explicitly. For filtration under static conditions linearization leads to a boundary value problem analogous to a heat flow problem with a known explicit solution. The corresponding solution for static filtration is compared with published experimental data. Under dynamic conditions filtration takes place in three successive stages. During each of these the rate of filtration and/or the thickness of the filter cake are different functions of the filtration time. The proposed mechanism explains the observed high resistance of dynamically deposited filter cakes against erosion and also the connection between filtration rate and viscosity of the drilling fluid. Several of the quantities governing dynamic filtration have no counterpart in the static filtration mechanism. The static filtration rate is, therefore, not a reliable measure for the dynamic rate and vice versa. INTRODUCTION Filtration under simulated borehole conditions, i.e.. either from a static suspension or from a suspension flowing parallel to the filter cake (dynamic filtration), has been the subject of several laboratory studies.1-7 This experimental and theoretical work showed that many aspects of the filtration mechanism cannot be explained by an elementary filtration theory based on the assumption that the filter cake is incompressible. For a more satisfactory theory compressibility should be taken into account. This has been done. at least to some extent, in the filtration theory developed for the chemical industry. Surveying the literature (see Ref. 8 for a bibliography) it becomes apparent that, although several properties of filter cakes deposited from many different suspensions have been measured, including compressibility, the filtration equations are essentially empirical in nature. No attempt has been made, for instance, to develop filtration theory along the lines of consolidation theory.12 This theory, upon which a highly successful development in soil mechanics rests, would appear to be an excellent starting point for a filtration theory since the compressibility concept is an essential part of it. As we will use this theory in the following development it is well to state the four assumptions on which it is based: 1. The fluid flow through a compressible porous medium is governed by Darcy's law. 2. The rate of change in fluid content of an element of the porous medium is proportional to the rate of change of solid pressure between the particles. 3. The solid particles are incompressible within the range of pressures considered. 4. The total pressure on a surface normal to the line of flow is equal to the sum of the fluid pressure and the pressure between the particles (solid pressure) at that surface. To calculate the rate of filtration and other quantities of interest it is necessary to know the filter cake compressibility and the permeability as a function of the solid pressure. It has not been possible to calculate these functions from theoretical considerations and they will therefore be introduced in this paper as empirical expressions. Both are determined in a compression cell where the cake is subjected to a mechanical load. Permeability and compressibility are measured after the solid pressure has stabilized, i.e., after the excess fluid pressure has been dissipated and the uniform pressure is transmitted entirely by the solids. The permeability and compressibility thus determined are not the same as during filtration in the borehole, under either static or dynamic conditions, because then, due to frictional drag, the solid pressure and hence also the permeability and compressibility vary along a line normal to the direction of the mean flow and can only be defined locally. DERIVATION OF THE FILTRATION EQUATION FOR COMPRESSIBLE FILTER CAKES As the filter cake in the borehole is thin compared to the radius of the hole the filtration may be considered as linear. Taking the x-axis normal to the wall, with its origin at the formation, we have, according to Darcy's law,

SOUTHERN CALIFORNIA LOCAL SECTION Executive Committee SEELEY W. MUDD, Chairman C. COLCOCK JUNES, Vice-Chairman FREDERICK J. H. MERRILL, Secretary-Treasurer, 631. Higgins Bldg., Los Angeles, Cal. Ralph ARNOLD A. B. CARPENTER The Second Annual Meeting of the Southern California Local Section of the American Institute of Mining Engineers was held at 300 Germain Bldg. on June 18, 1915, at 8 P.M. Present were: Messrs. C. Colcock Jones, Carpenter; Merrill, Baumgarten, Staunton, Hodges, Holland, and Durell. In the absence of the Chairman; Mr. Jones presided. The tellers appointed to canvass the vote for Section officers reported 45 ballots cast. The following gentlemen were announced as duly elected to the several. . offices: Chairman, SEELEY W. MUDD, Vice-Chairman, C. COLCOCK JONES, Secretary-Treasurer, F. J. H. MERRILL, Members of Executive Committee, RALPH ARNOLD A. B. CARPENTER

Jan 8, 1915

Trans No. Place Date Vol. 1. Wilkes-Barre, Pa. May, '71 1 2. Bethlehem, Pa. Aug., '71 1 3. Troy, N. Nov., '71 1 4. Philadelphia, Pa. Feb., '72.. 1 5. New York, N. Y. May, '72 1 6. Pittsburgh, Pa. Oct., '72 1 7. Boston, Mass. Feb., '73 1 8. Philadelphia, Pa. May, '73 2 9. Easton, Pa. Oct., '73 2 10. New York N. Y. Feb., '74 2 11. St. Louis, Mo. May, '74 3 12. Hazleton, Pa. Oct., '74.. 3 13. New Haven, Conn. Feb., '75 3 14. Dover, N. J. May, '75 4 15. Cleveland, Ohio Oct., '75 4 16. Washington, D. C. Feb., '76 4 17. Philadelphia, Pa. June, '76 5 18. Philadelphia, Pa. Oct., '76 5

Jan 1, 1941

Trans No. Place Date Vol. 1. Wilkes-Barre, Pa. May, '71 1 2. Bethlehem, Pa. Aug., '71 1 3. Troy, N. Nov., '71 1 4. Philadelphia, Pa. Feb., '72.. 1 5. New York, N. Y. May, '72 1 6. Pittsburgh, Pa. Oct., '72 1 7. Boston, Mass. Feb., '73 1 8. Philadelphia, Pa. May, '73 2 9. Easton, Pa. Oct., '73 2 10. New York N. Y. Feb., '74 2 11. St. Louis, Mo. May, '74 3 12. Hazleton, Pa. Oct., '74.. 3 13. New Haven, Conn. Feb., '75 3 14. Dover, N. J. May, '75 4 15. Cleveland, Ohio Oct., '75 4 16. Washington, D. C. Feb., '76 4 17. Philadelphia, Pa. June, '76 5 18. Philadelphia, Pa. Oct., '76 5

Jan 1, 1934

Trans No. Place Date Vol. 1. Wilkes-Barre, Pa. May, '71 1 2. Bethlehem, Pa. Aug., '71 1 3. Troy, N. Nov., '71 1 4. Philadelphia, Pa. Feb., '72.. 1 5. New York, N. Y. May, '72 1 6. Pittsburgh, Pa. Oct., '72 1 7. Boston, Mass. Feb., '73 1 8. Philadelphia, Pa. May, '73 2 9. Easton, Pa. Oct., '73 2 10. New York N. Y. Feb., '74 2 11. St. Louis, Mo. May, '74 3 12. Hazleton, Pa. Oct., '74.. 3 13. New Haven, Conn. Feb., '75 3 14. Dover, N. J. May, '75 4 15. Cleveland, Ohio Oct., '75 4 16. Washington, D. C. Feb., '76 4 17. Philadelphia, Pa. June, '76 5 18. Philadelphia, Pa. Oct., '76 5

Jan 1, 1942

By Stuart E. Buckley, C. R. Hocott

The viscosity of the oil in the reservoir is one of the properties that influence its movement through the sand to producing wells. Measurements of viscosity, therefore, are pertinent to problems associated with well behavior and with the estimation of recoveries, and afford an indirect means for partial evaluation of various methods of controlling reservoir behavior. The effect of dissolved gases on the viscosity of crude oil has been determined,ls2 but no data have been published on the viscosity of representative samples of reservoir oils. This paper describes a simple instrument that has been used to determine the viscosities of a number of subsurface oil samples at the temperatures and pressures existing in the reservoirs, and presents the results of the determinations for typical fields. Construction oF the Apparatus The principal requirements of any instrument used for the examination of subsurface samples are that it be strong and simple both in design and in method of operation. Accuracy beyond that of the degree of reproducibility of subsurface Sam-~les from various wells in a reservoir or exceeding that of the common measure-merits of reservoir temperatures and Pressures is not required. Because of the expense of procuring subsurface samples, it is necessary also that the instrument operate on a relatively small fraction of a sample, leaving the remainder for other tests, and that there be few or no failures of the equipment to cause undue delay or loss of a sample. After preliminary experiments with a falling bullet, the results of which were not satisfactory, a simple viscosimeter was built of the rolling ball type first proposed by Flowers3 and later used by several investiga-tor. 5.8 The apparatus consists essentially of a removable, accurately bored cylindrical barrel of 1/4-in. nominal internal diameter, 8 in. long, in which a closely fitting steel ball rolls through the oil with the barrel inclined at a definite angle. The ball makes contact at one end of the barrel with ail insulated electrode, closing an electrical circuit, which actuates a buzzer. The meas-urements consist essentially in determining the time required for the ball to travel the length of the barrel. The details of the construction are shown in Fig. I. The barrel in which the ball rolls was made from a section of 25-caliber blank rifle barrel, specially bored to an exact uniform diameter and polished. The barrel slides snugly into a hole bored in a solid stainless-steel cylinder, an upper external shoulder of the barrel compressing a small spring, and is held in place by a hollow nut. The spring prevents the barrel from seating against the bottom of the bored hole in the cylinder, while narrow external longitudinal slots in the barrel permit fluid to flow around it and through the bottom. The upper part of the recess in the steel cylinder is enlarged to form a tapered chamber, which acts as a reservoir for the oil and affords space for agitation to ensure

Jan 1, 1941

By C. R. Hocott, Stuart E. Buckley

The viscosity of the oil in the reservoir is one of the properties that influence its movement through the sand to producing wells. Measurements of viscosity, therefore, are pertinent to problems associated with well behavior and with the estimation of recoveries, and afford an indirect means for partial evaluation of various methods of controlling reservoir behavior. The effect of dissolved gases on the viscosity of crude oil has been determined,ls2 but no data have been published on the viscosity of representative samples of reservoir oils. This paper describes a simple instrument that has been used to determine the viscosities of a number of subsurface oil samples at the temperatures and pressures existing in the reservoirs, and presents the results of the determinations for typical fields. Construction oF the Apparatus The principal requirements of any instrument used for the examination of subsurface samples are that it be strong and simple both in design and in method of operation. Accuracy beyond that of the degree of reproducibility of subsurface Sam-~les from various wells in a reservoir or exceeding that of the common measure-merits of reservoir temperatures and Pressures is not required. Because of the expense of procuring subsurface samples, it is necessary also that the instrument operate on a relatively small fraction of a sample, leaving the remainder for other tests, and that there be few or no failures of the equipment to cause undue delay or loss of a sample. After preliminary experiments with a falling bullet, the results of which were not satisfactory, a simple viscosimeter was built of the rolling ball type first proposed by Flowers3 and later used by several investiga-tor. 5.8 The apparatus consists essentially of a removable, accurately bored cylindrical barrel of 1/4-in. nominal internal diameter, 8 in. long, in which a closely fitting steel ball rolls through the oil with the barrel inclined at a definite angle. The ball makes contact at one end of the barrel with ail insulated electrode, closing an electrical circuit, which actuates a buzzer. The meas-urements consist essentially in determining the time required for the ball to travel the length of the barrel. The details of the construction are shown in Fig. I. The barrel in which the ball rolls was made from a section of 25-caliber blank rifle barrel, specially bored to an exact uniform diameter and polished. The barrel slides snugly into a hole bored in a solid stainless-steel cylinder, an upper external shoulder of the barrel compressing a small spring, and is held in place by a hollow nut. The spring prevents the barrel from seating against the bottom of the bored hole in the cylinder, while narrow external longitudinal slots in the barrel permit fluid to flow around it and through the bottom. The upper part of the recess in the steel cylinder is enlarged to form a tapered chamber, which acts as a reservoir for the oil and affords space for agitation to ensure

Jan 1, 1941

By AIME AIME

JOHN LIVERMORE CHRISTIE belongs to that group of metallurgists who entered the industrial field during World War I and have been responsible for many of the important metallurgical developments since that time. He was born in Montclair, N. J., on Jan. 31, 1894. After graduating from Montclair High School he attended Sheffield Scientific School, Yale University, received his Ph.B. degree in chemistry in 1915 and that same year was employed by the Bridgeport Brass Co. in its laboratory. Among his first duties was the return to Sheffield Scientific School for two years of graduate work in metallography under C. H. Mathewson; receiving his M.S. degree in 1917. Thus we see him becoming one of that group of eminent physical metallurgists who, with Dr. Mathewson's teaching as a foundation, have done outstanding work in metallurgy.

Jan 1, 1945

By R. M. Rose, D. P. Ferriss, J. Wulff

Single crystals of tantalum, tungsten, and the binary alloys thereof were grown by electron-beam zone melting and tested in tension between 77° and 373°K. The ductile-to-brittle transition temperature increased sharply with solute concentration, for both tungsten-rich and tantalum-rich alloys; apparently, the maximum transition temperature exists near the 50 pet concentration. Twinning was observed to be a consequence of cleavage-crack propagation. Cleavage occurred on(100)planes, and extensive tearing and "river markings" were present. The onset of brittleness could not be associated with any change in deformation mode, the yield point phenomenon, or the large rise in yield stress with decreasing temperature. Cleavage was observed to initiate at either the specimen surface, or subgrain boundaries. The observation was made that the grain boundaries of Polycrystalline materials are probably even better as nucleation sites for fracture, and are responsible for brittleness at high temperatures and lower solute concentrations than those of the corresponding single crystals. TUNGSTEN and tantalum, the two high-melting neighbors in the third transition period of the periodic table, present striking contrasts. Although both are bee, tungsten has far higher elastic moduli, and the highest ductile-to-brittle transition (DBT) of all the pure metals.' Tantalum, however, is ductile at liquid helium temperatures. Large strain aging and yield point phenomena are observed in tantalum,2,3 but only to a lesser extent in tungsten.4 Tungsten work-hardens at a high rate,5 whereas this effect is negligible in tantalum.' Since the mutual solid solubility of these two metals is complete,7 and no ordering has yet been reported in the binary system, the possibility of depressing tungsten's DBT by tantalum additions was considered. Also, tungsten additions to tantalum could produce hard, high-melting alloys which might be ductile at room temperature. Such alloys offered excellent bases for complex alloy development, particularly with regard to the effect of rhenium on Group VI metals.8"10 In addition, there was the opportunity to examine flow and fracture modes in the vicinity of the DBT, with particular emphasis on the correlation between brittleness and fundamental deformation mechanisms. Myers11 has reported that recrystallized alloys with up to 10 pet W in tantalum are ductile at room temperature, but alloys with 20 pct W could not be swaged at temperatures as high as 500°C. The whole spectrum of Ta-W alloys has been surveyed by Braun, Sedlatschek, and Kiefferl2 using sintered powder compacts. In addition to some physical properties they reported a maximum hardness at about 50 at. pet W, dropping to much lower hardness levels for the pure components. They were able to cold work tantalum-base alloys with as much as 30 pet W and to warm work tungsten-base alloys with up to 20 pet Ta by procedures similar to those used for pure tungsten. EXPERIMENTAL In order to study deformation modes and to keep the impurity concentrations at a minimum, electron-beam zone melting was used to prepare single crystals of high purity. The electron-beam zone melting apparatus is similar to that described by Calverley, Davis, and ever" and incorporates a grid control rectifier to maintain control of emission current. Pure metals were refined by making three zone passes at 4 mm per min up the rod. Alloys were prepared by melting together wire of one constituent on a previously melted rod of the major constituent. Subsequently, two zone passes were made in opposite directions to level the composition after the manner suggested by pfann.14 Purification of the starting materials was accomplished by evaporation of the several impurities, and the degree to which this was accomplished is indicated in the chemical analyses of Table I. The uniformity of composition along a zone levelled rod was within the i 1 pet accuracy of the fluorescent X-ray technique used to determine composition. Crystallographic orientation of the

Jan 1, 1962

PERSONAL (Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who registered at Institute headquarters during. the period May 10 to June 10, 1915: Robert M. Keeney, Somersville, Conn. C. A. Moffett, Birmingham, Ala. Emilio Mosonyi, San Salvador, C. A: A. W. G. Wilson, Ottawa, Canada. Junjiro Nagazumi, Fukuoka, Japan. G. H. Glover, Jr., Short Hills, N. J. Francis R. Pyne, Elizabeth, N. J. R. W. Brock, Vancouver, B. C. F. C. Alsdorf, Los Angeles, Cal. J. L. W. Birkinbine, Philadelphia, Pa. W. J. Loring, London, England. Roy H. Allen, Jamesburg, N. J. R. A. Bull, Granite City; 111. Francis Andrew Thomson received the degree of Master of Science from the Colorado School of Mines at the recent commencement exercises. The subject of his thesis was Stamp Milling and Cyaniding.

Jan 7, 1915

MONTANA LOCAL SECTION Executive Committee F. M. SMITH, Chairman J. L. BRUCE, Vice-Chairman . D. C. BARD, Secretary, Box 267, Butte, Mont. FREDERICK LAIST W. C. SIDERFIN The semi-annual meeting of the Montana Section was held at the Silver Bow Block, Butte, Mont., on Friday evening, Oct. 8, 1915. An informal, subscription dinner, at $1.50 a plate, was enjoyed inn' the early evening, by 62 members and guests. After dinner a technical session was held, and a paper entitled Preliminary Outline of Paper on Mines in the Boulder Batholith was presented by J. A. Grimes, who is joint author of the paper, with Paul Billingsley. The paper elicited a lively and interesting discussion, in which a score of members took part. After the reading of the paper the rest of the evening was spent socially. D. C. BARD, Secretary.

Jan 12, 1915

By R. K. Matheson

THE Nivloc mine is 9 miles west of Silver Peak, Esmeralda County, Nevada. It has been operated by Desert Silver, Inc., since the summer of 1937. The cyanide mill treats 19o tons of silver-gold ore per day. In March of this year the main operations were about 2000 ft. west of the main shaft, which served as the downcast air passage for the mine. The mechanical blowers in use were sufficient to ventilate the west end at that time, but it was foreseen that as the mining area was extended ventilation would be an increasingly difficult problem, especially during the summer months. It was decided, therefore, to continue a raise from a point 100 ft. above the highest mining level (440-ft. level) to the surface; a distance of 443 ft. at approximately 65° From this point 40 ft. of drifting would be necessary to connect with a shallow shaft on the surface. (Fig. I.) All the raise was serviced from the 440-ft. level; costs and progress obtained in the initial 100 ft. are included in the following pages. CHOICE OF RAISE A raise in this locality would have four objects: (I) to provide an ample supply of fresh air to the working places; (2) to explore the vein from the highest mining level to the surface; (3) to provide waste fill for stopes in the area, and possibly provide a transfer for waste from the surface; (4) to provide an emergency exit in the west end of the mine. Before the mining of an ore shoot in the eastern part of the mine, a similar raise had been driven for purposes of ventilation and exploration. This raise and subsequent mining showed the vein to be noncommercial for a distance of about 250 ft. below the surface. However, in the area under operation, old surface workings showed occasional values. Thus from a development standpoint the raise was an excellent prospect. The raise chosen was a three-compartment, stulled raise having two chutes and a manway. The manway inside timber measured 4 ft. 8 in. by 4 ft. 6 in.; it carried air and water pipes, a ladderway and a slide for a timber skip. The two chutes would be used for drawing off the muck and the cleaning of the bulkhead, as well as for ore and waste passes, which would be especially useful for lateral exploration from the raise. The fairly large cross section of the raise (6 by 15 ft.) would provide a large quantity of waste for backfilling, and more could be obtained from a glory hole on the surface. TIME SCHEDULE As speed in completing the raise was the main requisite, three shifts were considered, but two shifts were decided upon when it was found that three would necessitate considerably larger fans than those available for clearing the raise. The main diffi-

Jan 1, 1942