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By John Birkinbine

This piece of Carpenter crucible steel has exhibited a tensile strength of 116,000 pounds per square inch, an elastic limit of 89,170 pounds, an elongation of 25 per cent., and a reduction in area of 42 per cent. The test-specimen had a length of 2 inches between fillets, and was an inch bar reduced to an area of 0.504 square inch. This unusual tensile strength was determined before the bar had been hardened so as to show the remarkably velvety fracture here exhibited; but a piece of the same, tested after hardening, is reported to have stood a stress of 214,000 pounds per square inch. Another test-piece is said to have shown 136,000 pounds tensile strength, 97,300 pounds elastic limit, 20 per cent. elongation in 2 inches, and 40 per cent. reduction of area. Mr. Carpenter claims that this steel, containing 2.27 per cent. chromium and 1.04 per cent. carbon, can be welded like iron, and has proved most desirable,for the highest class of die-steel.

Jan 1, 1895

The following officers and committee chairmen were elected: Honorary Chairman, Herbert Hoover; Chairman, Elmer A. Sperry, New York; Vice-Chairman and Chair-man of the Executive Committee, John W. Lieb, New York; Vice-Chairman, C. E. Grunsky (Pacific Coast), San Francisco; C. F. Kettering (Middle West), Detroit; Execu-tive Secretary, Maurice Holland; Executive Committee: Gano Dunn, George W. Fuller, Maurice Holland, Frank B. Jewett, John W. Lieb, H. J. McGraw, Calvin W. Rice, W. E. Wickenden, all of New York; Dugald C. Jackson, Cambridge, Mass.; 0. C. Merrill, Washington, D. C.; Charles F. Scott, New Haven, Conn.; Elmer A. Sperry, Brooklyn, N. Y.; Finance Committee. John W. Lieb; Technical Program Committee: D. C. Jackson; Transporta-tion Committee: F. B. Jewett; Entertainment Committee: 0. C. Merrill; Publicity: J. H. McGraw; Promotion and Attendance: George W. Fuller.

Jan 5, 1928

Reports on process control computer projects at the Kamioka Plant are summarized from the Japanese technical literature (see references). Fluidized Bed Roaster and Sulfuric Acid plant1 A small process control computer (Yokogawa CCS-200 with an OKITAC 5090P 8K central processor) was installed in the Kamioka smelter in the summer of 1964. A year-and-one-half installation project followed, which successfully brought the roaster and acid converters under computer control. The process plant consisted of two 130 RPD fluosolids roasters and two Monsan to acid units. The roasters are charged with lead-zinc concentrates with SO2 from the roaster processed to sulfuric acid. The computer system provides the following functions: 1) log data from the plant--the input is taken from 50 analog signals, 130 high-low digital alarm points, and 50 analog high- low alarm points; 2) set-point control on 18 control loops; 3) direct digital control (DDC) on eight control loops for which conventional controllers were difficult to adapt due to abnormal loop characteristics or delay times; 4) execution of a safe shut-down procedure

Jan 1, 1969

By Gordon E. Agar

Several correlations have been proposed to relate energy consumption and size reduction in comminution, and although these are arrived at from different starting points, it is postulated that they are all statements of the same basic concept. To test this postulate, the dry ball mill grindability of langbeinite was determined, and the results were analyzed according to the various methods. An examination ' of the energy-particle size relationships proposed in the recent past revealed that they had much in common. In fact, the conclusion was tentatively drawn that these expressions were essentially the same, even though they were arrived at from quite different basic premises. The equations attributed to Charles2 and Holmes3 were shown to re- duce to the same single equation, W - A K-3, and the simulated continuous test used by Maxson et al.4 was shown to give the best experimental value of the required empirical parameter, ß. Furthermore, the size distribution parameter a in the Schuhmann equation, y - (x/K)2, was shown to be equal to ß in many cases. The kinetic approach used by Arbiter and Bhrany5 should give the same results as the Maxson test procedure; however, the batch operation used by Arbiter and Bhrany could not produce data that would be as precise as the simulated continuous technique. To test the validity of these conclusions, the simulated continuous method was used to obtain data on the dry grinding of langbeinite. The results are discussed in terms of the various equations and approaches. APPARATUS AND MATERIAL A ball mill with internal dimensions of 17.5 cm (6 7/8 in.) in length by 19.4 cm (7 5/8 in.) in diam was loaded to 50% of its volume with balls 3.2 cm in

Jan 1, 1969

By Donald O. Rausch, Adolph Soderberg

4.1-1. Introduction. Open pit mine planning must be correlated to all phases of a mining operation. The factors that must be considered in planning an open pit mine are numerous and must reflect the characteristics and surrounding conditions of a particular orebody. Therefore, only an outline of the subject can be presented here to aid the planning engineer in pointing out procedures that are generally applicable to pit design. The presentation is directed toward the planning of an open pit copper mine, but the procedures discussed should apply in most cases to any type of metallic or nonmetallic orebody. In planning an open pit mine the pertinent elements that must be included are: assays, geology, tonnage and areal extent of ore reserves, topography, mining equipment, economic factors of operating costs, capital expenditures, profit, types of ore, pit limits, cut-off grade, stripping ratio, rate of production, pit slopes, bench heights, road grades, ore metallurgical characteristics, hydrological conditions, property lines, and marketing considerations. 4.1-2. Sampling. Sampling must be adequate to classify the various materials to be removed from an open pit mine. Drillhole assays are plotted on sections and plan maps with ore and waste blocked out by selected bench intervals. These maps are prepared to depict the geological and other conditions existing on each mine level. The confidence factor to be applied to sampling and the resultant assays values must be given careful consideration. In uniformly disseminated de- posits, the confidence factor will approach unity. For widely fluctuating values, the average assay values should be discounted somewhat, the degree depending upon such factors as drillhole spacing. Such samples, at best, represent a very few pounds for hundreds to thousands of tons of ore

Jan 1, 1968

By H. Wilhelm, E. L. Davis, W. A. Clark

MATHEMATICAL formulas for the analysis of the behavior of producing oil wells can be devised which will be correct for the assumed conditions. However, in an oil zone, variables always exist which are unknown, or to which. it is impractical to assign mathematical values. It seems apparent that one should reason back from observed facts to an analysis of causes, rather than start with a hypothetical reservoir with assumed properties and attempt to explain observed phenomena. In this paper we hope to throw some additional light on factors influencing production, especially edgewater behavior. OIL and gas are contained in reservoirs of either the sealed type or the edgewater type. In the former all the recoverable oil is produced by gas expansion only. In this type of reservoir, edgewater is not effective. This may be because of faulting or overlapping strata, or more often, probably, the edgewater pressure is ineffec¬tive on account of resistance or lack of head.

Jan 1, 1933

By L. A. Willey, William L. Fink

TWO of the aluminum-alloy systems previously studied—the aluminum-titanium and the aluminum-chromium—exhibit a peritectic reaction at the extreme aluminum end of the diagram. Preliminary work indicated that the aluminum-zirconium and certain other aluminum systems were similar in this respect. The present paper, the twentieth of a series from the Aluminum Research Laboratories, reports the results of a recent investigation of equilibrium relations in aluminum-zirconium alloys of high purity, which confirm the preliminary observations. Previous Investigations There has been only one investigation of the aluminum end of the aluminum-zirconium system. Sykesl prepared and studied alloys containing 0 to 70 per cent Zr. The lowering of the freezing point of aluminum by the addition of zirconium was found to be very little, if any (less than 2" C.). He placed the solid solubility of zirconium in aluminum at room temperature between 0.57 and 0.97 per cent. A few other investigators have attempted to determine the composition of the intermetallic compounds occurring in this system. Honigschmid2 obtained the compound ZrAla as a by-product during the preparation of ZrSi2. He made no attempt to prepare other aluminum-zirconium compounds. Weiss and Newmann3 prepared an alloy by heating aluminum with a double fluoride of potassium and zirconium. When this alloy was treated consecutively with caustic soda and hydrochloric acid, there was a residue, which contained approximately 72 per cent Zr and 28 per cent A1 (Zr3AI4). Marden and Rich4 prepared an alloy in the same way, treated it with caustic soda, and obtained a residue of silver-white crystals, which contained 70 per cent Zr and 30 per cent A1 (Zr3A14). Alloys Materials Used.—Electrolytically refined aluminum was employed for thc preparation of all alloys used in this investigation. The chemical

Jan 1, 1939

By William L. Fink, L. A. Willey

TWO of the aluminum-alloy systems previously studied—the aluminum-titanium and the aluminum-chromium—exhibit a peritectic reaction at the extreme aluminum end of the diagram. Preliminary work indicated that the aluminum-zirconium and certain other aluminum systems were similar in this respect. The present paper, the twentieth of a series from the Aluminum Research Laboratories, reports the results of a recent investigation of equilibrium relations in aluminum-zirconium alloys of high purity, which confirm the preliminary observations. Previous Investigations There has been only one investigation of the aluminum end of the aluminum-zirconium system. Sykesl prepared and studied alloys containing 0 to 70 per cent Zr. The lowering of the freezing point of aluminum by the addition of zirconium was found to be very little, if any (less than 2" C.). He placed the solid solubility of zirconium in aluminum at room temperature between 0.57 and 0.97 per cent. A few other investigators have attempted to determine the composition of the intermetallic compounds occurring in this system. Honigschmid2 obtained the compound ZrAla as a by-product during the preparation of ZrSi2. He made no attempt to prepare other aluminum-zirconium compounds. Weiss and Newmann3 prepared an alloy by heating aluminum with a double fluoride of potassium and zirconium. When this alloy was treated consecutively with caustic soda and hydrochloric acid, there was a residue, which contained approximately 72 per cent Zr and 28 per cent A1 (Zr3AI4). Marden and Rich4 prepared an alloy in the same way, treated it with caustic soda, and obtained a residue of silver-white crystals, which contained 70 per cent Zr and 30 per cent A1 (Zr3A14). Alloys Materials Used.—Electrolytically refined aluminum was employed for thc preparation of all alloys used in this investigation. The chemical

Jan 1, 1939

By MCA Woolsey

(Butte. Meeting, August, 1913.). IN metallurgical circles it is known widely, but somewhat vaguely, that the ease of: reduction of metallic oxides depends largely on the way they have been prepared. It is likewise known that different forms of carbon have different and greatly varying reducing powers. It is the purpose of this paper to show somewhat more definitely and scientifically these facts. Some years ago the writer published an account of pyrometric determinations of the reduction- temperature of zinc oxides variously prepared and of several kinds.1 In said paper it was shown that the temperature it which zinc oxide evolves zinc according to the equation Zn0. +' C = Zn + CO depends upon the ;nature of:., the.' two reacting bodies. The determinations bad a range of accuracy of from 2° to. 6° C.,whereas differences were found to. amount to an extreme. of 90° C. :.86 the differences are real ones and must have, definite cause. The equation of boiling water, (H20)4 = 4 (H2O) has a fixed temperature for equilibrium of 100° C. at 760 mm. pressure. , In general, all equations. reacting e in .the liquid or the gaseous phase have-well-defined constant physical conditions which govern the equilibrium point and reaction velocities. In a reaction where we have one or more solid phases, the temperature conditions requisite for the unbalancing of the stable system are found to vary. These variations are due to the fact that in a solid there is a very complex molecule and it is not, a question solely of the tearing away of two interlocked atoms, but also of the destruction of a complex molecule containing hundreds, or possibly thousands, of smaller molecules.

Jan 7, 1913

By Victor O. Strobel

Fire-brick hot-blast stoves have been the subject of frequent discussions at the meetings of the Institute; and although it is my object to elucidate some of the points in connection with this subject, I will not go into the specific features of all types, but more especially call attention to a new type recently designed by Mr. Fred. W. Gordon. As the economical production of a ton of pig-iron is a more essential feature than a large output, much depends, where fuel cannot be obtained cheaply, upon suitable apparatus whereby high temperatures can be maintained. Where iron-pipe stoves have been employed, the fuel-consumption reached one and a half pounds of fuel, and, when a larger output was desired, often two pounds, to the pound of iron produced. The temperature attained rarely exceeded 900' F., and that at the expense of frequent renewals of the pipes, which was not inconsiderable. The fire-brick hot-blast stoves of the past five or six years have clearly demonstrated their superiority over the old system. Of the accompanying drawings, Fig. 3 illustrates a four-pass regen-

Jan 1, 1886

By S. K. Mitra

A refinement of the Seeger model for intersection process is investigated which is in better agreement with experimental observations than the original. It is shown that, in single crystals, the strain hardening in Stage II is mainly due to the short-mnge interactions when intersection is the rate-controlling process. It is also demonstrated that the creep curves, as predicted by this theory, are in good agreement with the experimental observations. MOTT: Cottrell? and Seeger have developed an approximate theory for plastic deformation of single crystals over the range of variables where the strain rate is controlled by the rate of intersection of dislocations. Although it is now generally agreed that the low temperature deformation of many pure metals is controlled by the intersection mechanism, various dictates of the over-simplified Seeger model are not in good agreement with all the experimental facts. It is the purpose of this paper to reveal that by appropriate extensions of the Seeger model, particularly those suggested by Basinski: a much more reliable theory results. The refined model to be presented here will be shown to account, in a satisfactory way, for the effect of stress, temperature, and strain on the creep rate under constant stress and for the effect of temperature and strain on the flow stress in constant strain-rate tests. EXPERIMENTAL METHOD To Check the theoretical deductions, both creep and tension tests were conducted on single crystals of high-purity Al (99.994 pct Al) so oriented that both the active slip plane and the Burger's vector of the operative dislocations on that plane made angles of about 45 deg to the tension axis. Single crystals of aluminum (5/8 in. by 1/10 in. by 8 in.) were grown in a graphite mold under an inert atmosphere using the Bridgman method. The chemical composition of the aluminum is given in Table I. A common seed was used for all crystals and their orientation is shown in Fig 3. The extensometry consisted of two differential transformers with matched outputs mounted so as to measure the extension in a 2 in. gage length. The amplified difference in output of the two transformers was recorded by a potentiometer. The amplification was calibrated before each run so that one chart division of the recording potentiometer indicated a 105 shear strain on the specimen. Stresses were measured to the nearest 1 x l04 dynes per sq cm. ACTIVATION VOLUME The concept of Basinski that the activation volume is not constant but is a function of the force that aids thermal fluctuation in effecting the cutting of dislocations will be adopted in this section. The force acting due to an applied shear stress on the dislocation being intersected is where L is the mean spacing between the forest dislocations, is the Burger's vector and T is the back stress. A detailed discussion about the origin of back stress will be taken up later in this report. As shown by Basinski, the activation energy, U, that must be supplied by a thermal fluctuation in order to effect intersection, is equal to where x is the distance through which the dislocation must be translated for complete intersection, and Fm is the maximum force encountered in intersection. When the applied stress is decreased abrupt ly F also decreases and the activation energy increases correspondingly as documented in Eqs. [ 1 ] and [2]. The Seeger equation for the strain rate when the deformation is controlled by rate of intersection of where the shear strain rate (per sec) N = the number of points per unit vol at which intersection can take place

Jan 1, 1962

By Charles Hart

A STUDY of the various ores that have been discussed impresses one with the need of beneficiation, in many cases. This applies to the ores that have lain dormant, due to necessity for further preparation, or to ores that now find a market due to a changed condition. Processes of beneficiation will come into their own as our richer ores become exhausted. Many efforts at improvement have been commercial failures, due to prematurity. Thomas A. Edison, with characteristic foresight, attempted concentration of the low- grade New Jersey magnetites some thirty years ago. Due to high costs and the discovery of the Mesabi range, his efforts were futile. However, a successful crusher, designed by Mr. Edison, resulted from this attempt. Agglomeration of concentrates had not, at that time, been brought to its present efficiency, when sinters and briquettes of excellent physical condition are obtainable. Recent efforts in the beneficiation of the lean magnetites of the East Mesabi resulted in an excellent sinter, but that operation is also ahead of its time.

Jan 1, 1929

By Joseph Fry, Ralph H. Espach

In the spring of 1943, when it was evident that the Tensleep bandstone in the Elk Basin Field, Wyoming and Montana, held a large reserve of petroleum, Bureau of Mines engineers obtained samples of oil from the bottom of nine wells and analyzed them for such physical characteristics as the volumes. of gas in solution. saturation pressures or bubble points, shrinkage in volume caused by the release of gas from solution, expansion of the oil with decrease in pressure, and other related properties. The composition of the gas in solution in the oil was studied. The pressures and temperatures existing in the reservoir and the productivity characteristics of the oil wells were determined. The data obtained indicate that the oil in the Tensleep Reservoir of the Elk Basin Field has unusually varying physiral characteristics, such as a saturation pressure of 1,250 psia and 490 cu ft of gas in solultion in a barrel of oil at the crest of the structure and a saturation pressure of 530 psia and 134 cu ft of gas in solution in a barrel of oil low on the flanks. The hydrogen sulfide content of the gas in solution in the oil varies from 18 per cent for oil on the crest to 5 per cent for oil low on the flanks of the structure. Of even greater significance is the fact that these and other variable characteristics of the reservoir oil are related to the position of the oil in the structure. Many geologists and petroleum engineers have considered that all the oil in a petroleum reservoir has rather uniform physical characteristics and that equilibrium conditions prevailed in all underground accumulations of oil and gas; that such is not always so is borne out by the results of the study by the writers. INTRODUCTION The Rocky Mountain region is one in which may be found striking examples of the unusual in oil and gas accumulations, as is evident from the following: The high helium content (7.6 per cent) of the gas in the Ouray-Leadville limestone sequence in the Rattlesnake Field, New Mexico, and gases of similar helium content in other fields; 50" to 55' API gravity distillate in solution in carbon dioxide gas and recoverable through retrograde condensation, in the North McCallum Field, Colorado; the occurrence of gas, oil, or both in closely related structures contrary to the usual concepts of gravimetric segregation: the accumulation of gas and/or oil in structures closely related to other structures that apparently are more favorable but do not contain oil or gas accumulations; the high hydrogen sulfide content (as high as 42 per cent) of the gas associated with oil in some fields in the Big Horn Basin, Wyoming; and the wide range of fluid chararteristics found in the Elk Basin reservoir. Elk Basin, an interesting old oil field that has been producing oil from the Frontier formation since 1915, is situated in a highly eroded basin resulting from the erosion of the crest of an anticline and some of the underlying softer shales. The field came back into national prominence during 1943 when it became known that it was the largest single reserve of new oil discovered in the United States that year. The Tensleep sandstone was found to contain oil in November. 1942, when a well drilled to a depth of 4,538 ft (44 ft into the Tensleep sandstone) flowed oil at the rate of 2,500 B/D. By the end of 1949, 137 oil-producing wells and five dry holes had been drilled, and approximately 32 million bbl of oil had been produced. Approximately 6,000 acres may be considered productive of oil in the Tensleep Reservoir, and estimates of the oil that will be produced average 200 million bbl. The Tensleep Reservoir has further interest because it ha-greater closure than any oil field in the Rocky Mountain region; the closure of the Elk Basin anticline is variously estimated at 5.000 to 10,000 ft. of which the top 2.00 ft of the structure contained oil. SUBSURFACE OIL SAMPLING Fig. 1 is a structural map of the Elk Basin Tensleep Reservoir, on which the nine wells used in this study and the numbers correvponding to the well designations hereafter referred to are shown. Wells 1. 2, 3, 4, and 8 were tested and sampled during October and November. 1943. and Wells 5, 6. 7, and 9 during June and July, 1944. An electromagnetic type sampler developed by the Bureau of Mines and described by Grandone and Cook' was used in obtaining the subsurface oil samples. As the wells were tubed nearly to bottom, the sampler was run as far as possible in the tubing hut never below the top perforations. The following procedure was used in testing and sampling the wells: A well was shut in for at least three days, after

Jan 1, 1951

By Joseph Fry, Ralph H. Espach

In the spring of 1943, when it was evident that the Tensleep bandstone in the Elk Basin Field, Wyoming and Montana, held a large reserve of petroleum, Bureau of Mines engineers obtained samples of oil from the bottom of nine wells and analyzed them for such physical characteristics as the volumes. of gas in solution. saturation pressures or bubble points, shrinkage in volume caused by the release of gas from solution, expansion of the oil with decrease in pressure, and other related properties. The composition of the gas in solution in the oil was studied. The pressures and temperatures existing in the reservoir and the productivity characteristics of the oil wells were determined. The data obtained indicate that the oil in the Tensleep Reservoir of the Elk Basin Field has unusually varying physiral characteristics, such as a saturation pressure of 1,250 psia and 490 cu ft of gas in solultion in a barrel of oil at the crest of the structure and a saturation pressure of 530 psia and 134 cu ft of gas in solution in a barrel of oil low on the flanks. The hydrogen sulfide content of the gas in solution in the oil varies from 18 per cent for oil on the crest to 5 per cent for oil low on the flanks of the structure. Of even greater significance is the fact that these and other variable characteristics of the reservoir oil are related to the position of the oil in the structure. Many geologists and petroleum engineers have considered that all the oil in a petroleum reservoir has rather uniform physical characteristics and that equilibrium conditions prevailed in all underground accumulations of oil and gas; that such is not always so is borne out by the results of the study by the writers. INTRODUCTION The Rocky Mountain region is one in which may be found striking examples of the unusual in oil and gas accumulations, as is evident from the following: The high helium content (7.6 per cent) of the gas in the Ouray-Leadville limestone sequence in the Rattlesnake Field, New Mexico, and gases of similar helium content in other fields; 50" to 55' API gravity distillate in solution in carbon dioxide gas and recoverable through retrograde condensation, in the North McCallum Field, Colorado; the occurrence of gas, oil, or both in closely related structures contrary to the usual concepts of gravimetric segregation: the accumulation of gas and/or oil in structures closely related to other structures that apparently are more favorable but do not contain oil or gas accumulations; the high hydrogen sulfide content (as high as 42 per cent) of the gas associated with oil in some fields in the Big Horn Basin, Wyoming; and the wide range of fluid chararteristics found in the Elk Basin reservoir. Elk Basin, an interesting old oil field that has been producing oil from the Frontier formation since 1915, is situated in a highly eroded basin resulting from the erosion of the crest of an anticline and some of the underlying softer shales. The field came back into national prominence during 1943 when it became known that it was the largest single reserve of new oil discovered in the United States that year. The Tensleep sandstone was found to contain oil in November. 1942, when a well drilled to a depth of 4,538 ft (44 ft into the Tensleep sandstone) flowed oil at the rate of 2,500 B/D. By the end of 1949, 137 oil-producing wells and five dry holes had been drilled, and approximately 32 million bbl of oil had been produced. Approximately 6,000 acres may be considered productive of oil in the Tensleep Reservoir, and estimates of the oil that will be produced average 200 million bbl. The Tensleep Reservoir has further interest because it ha-greater closure than any oil field in the Rocky Mountain region; the closure of the Elk Basin anticline is variously estimated at 5.000 to 10,000 ft. of which the top 2.00 ft of the structure contained oil. SUBSURFACE OIL SAMPLING Fig. 1 is a structural map of the Elk Basin Tensleep Reservoir, on which the nine wells used in this study and the numbers correvponding to the well designations hereafter referred to are shown. Wells 1. 2, 3, 4, and 8 were tested and sampled during October and November. 1943. and Wells 5, 6. 7, and 9 during June and July, 1944. An electromagnetic type sampler developed by the Bureau of Mines and described by Grandone and Cook' was used in obtaining the subsurface oil samples. As the wells were tubed nearly to bottom, the sampler was run as far as possible in the tubing hut never below the top perforations. The following procedure was used in testing and sampling the wells: A well was shut in for at least three days, after

Jan 1, 1951

By T. T. Read

A SHORT time ago, one of the large steel companies courteously furnished the author with detailed records of the operations of a considerable number of iron blast furnaces over a period of two months. These will be made the basis of a subsequent study, but in beginning this study one of -the first points requiring consideration was the probable error of the records, for what otherwise might be regarded as significant differences of performance under different conditions were perhaps really due to errors of observation, or failure to observe and record variations. If it is assumed, in blast-furnace records and calculations, that known quantities or factors are constant, when as a matter of fact they are variable, the effects of these variations may erroneously be ascribed to some other cause. This is quite clearly expressed in the following quotation from E. Buckingham:1 Theory always operates on an ideally simplified picture of reality because real phenomena are unmanageably complicated. The results obtained are not exactly true for any, real phenomenon, though they may be for an ideal one; and the approxi¬mation with which a theoretical equation, however obtained, represents the actual facts, always depends on the approximation in essentials between the ideal picture and its real prototype. The purpose of dimensional reasoning is to find out how some quantity which is involved in the phenomenon under consideration is related to certain others; or to find the relation connecting two or more quantities which vary, or may vary, simulta-neously during the course of the phenomenon. Since we know that we must have a complete equation to start with, we begin by thinking the matter over, to see whether the quantities we have in mind are the only ones involved. Usually it is evident that they are not; so we next make a list of all the quantities we can think of which might under any circumstances be important. Upon considering this list, which is often a long one, it is usually evident that under the actual circumstances a number of these quantities may safely be ignored; so we cross them off the list and thus pass from our most general conception of the phenomenon to an ideal simpler one, in which these quantities are not involved at all.

Jan 3, 1925

By R. J. Blackwell, J. R. Rayne, J. R. Henderson, W. M. Terry, D. C. Lindley

This paper presents the results of a laboratory investigation of the efficiency of water-solvent mixtures in recovery of oil. These mixtures may have the high displacement efficiencies characteristic of solvent floods and the high sweep efficiencies characteristic of water floods. Thus, the water-solvent process may increase the number of reservoirs in which a miscible-type displacement can be used profitably. The experiments on the use of water-solvent mixtures for recovery of oil were conducted to find the general applicability of the process. These studies demonstrated that, in flowing through sands, water and solvent segregated into a solvent layer on the top and a water layer on the bottom rather than flowing through the sands as a uniform mixture. Calculations based on the simultaneous flow of the water and solvent in layers were used to predict the effective mobility of the mixtures and the optimum operation of the process in steeply dipping, homogeneous reservoirs. As most reservoirs are not suited for the operation of the process under ideal conditions, experimental studies were conducted with sand-packed models scaled to represent more realistic reservoirs. These studies included the effects on recovery of oil of rate of injection, viscosity of oil, variations of permeablity within a formation and variations in water-solvent ratio. For the range of con-ditions studied, higher recoveries of oil were obtained with water-solvent mixtures than with water or practical volumes of solvent alone. INTRODUCTION A group of intriguing—because of their great possibilities—new oil recovery methods at the disposal of the petroleum engineer are the miscible displacement processes. These processes (high-pressure gas drive, en-riched-gas drive and LPG bank driven by methane) displace all of the oil from the portions of the reservoir swept by the injection fluid. The key question confronting the engineer applying one of these techniques to a particular reservoir is, "What fraction of the reservoir can be swept by injection of a practical volume of solvent?"." Intensive laboratory studies have been made during the past several years in seeking answers to the question of the sweep efficiencies which can be expected in solvent floods.' - These studies provided the answer that low-viscosity, low-density solvents channel and by-pass oil in sands with no dip. In horizontal sands, solvent flooding becomes less efficient as the viscosity of the oil increases, the recovery of oil at solvent breakthrough decreases and larger volumes of solvent are required to achieve a given recovery. More efficient displacement of oil by solvent is observed under certain conditions in sands with dip.".' If the permeability and dip of the sand are sufficiently high, gravity segregation of low-density solvent injected updip can prevent channeling. At rates of depletion below a critical rate,"." no channeling occurs. Unfortunately, in many reservoirs, the critical rate is so low that production of oil at rates below this rate is not economically attractive. And at rates over four times the critical rate, channeling is almost as severe in sands with dip as in horizontal sands. These findings pointed out that, for solvent floods to be generally applicable in recovering oil from all types of reservoirs, new methods of improving their sweep efficiencies are needed. Simultaneous injection of water with the miscible fluid was suggested by Caudle and Dyes7 as a method for improving sweep efficiencies. They theorize that water flowing with the solvent would decrease the effective mobility of the solvent and cause it to contact more oil sand. If, indeed, the water and solvent flowed as a uniform mixture, the process should have the advantages of the high displacement efficiencies characteristic of miscible floods and the high sweep efficiencies of water floods. Thus, the method (at least in theory) would greatly increase the number of reservoirs in which miscible-type displacements would be feasible. A research program was conducted to probe the technical feasibility of the water-solvent process. It

By George H. Deike

DURING the past year a survey was conducted by the Committee on the Promotion of Student Interest in Coal Mining to determine whether the program as laid down in past years was operating effectively. It is a source of satisfaction and pleasure to be able to report considerable headway among operating companies in putting cooperative scholarship plans into operation. In previous committee reports the pioneer work along this line by Eugene McAuliffe, president of the Union Pacific Coal Co., has been cited. That Company now has in its employ, in responsible positions, three men who received their education under such scholarship plans. One student under a similar plan is now studying at the Colorado School of Mines.

Jan 1, 1942

By H. L. Sauder, J. L. Newman, C. Waddell

An instrument capable of measuring subsurface flow rates is described. The instrument is self-contained and may be run on piano wire line. It detects flow by means of an impeller suspended between two torsion wires. The force of the well fluid striking the impeller causes the impeller to rotate, exerting a torsional force to the wires. This force is determined by recording the angle of rotation of the impeller on film using a battery-driven, clock-controlled camera. The impeller is sensitive to flow in either direction and the same instrument can be used to measure injection as well as production rates. Changes in direction of flow, such as might be caused by thief zones, are measurable and are indicated by a reversal of the direction of rotation of the impeller. Adjustment of the sensitivity of the instrument to measure a wide range of flow rates is accomplished by the use of different size torsion wires. An umbrella-type fluid trap, which contacts the casing or wellbore, diverts the flow through the flow tube. The fluid trap remains closed while rurrning in the hole and can be opened at any point in the well. The instrument with the trap closed is 1 3/4 in. OD and may be run through 2 in. tubing. Successful flow profiles have been made on wells with flow rates ranging from 60 BID to 4,000 B/D at surface pressure up to 4,500 psi. The instrument is designed for high-pressure and high-temperature operations. INTRODUCTION The need for an instrument that will measure flow rates in a wellbore is as old as reservoir engineering itself. A number of such devices have been designed within the past few years. Some of these have been described in the literature1,2,3,4,5,6 One of these devices1. a hot-wire anemometer type, made many successful jobs in dry gas producing areas. Difficulty was encountered when this flowmeter was used in wells producing liquids and development work was initiated to overcome this difficulty. The present flowmeter is the result of this work and provides an instrument with a wider range of application in the industry. Consider- able development work has been done on the tool involving many changes in the mechanics of recording the flow readings, however, the basic principle of flow detection has remained the same since its inception. PRINCIPLE OF OPERATION The basic principle of operation of the flowmeter is the utilization of a portion of the kinetic energy of flowing well fluid to impart a rotational force to an impeller suspended between two torsion wires. This impeller, Fig. 1, is a screw-type propeller with the blades having a pitch angle of 40. As the well fluid passes through the instrument it strikes the impeller. The resulting force rotates the impeller and twist\ the torsion wires to a balance point at which the torque imparted to the wires balances the force required for the impeller to deflect the well fluid. The impeller is symmetrical and a change in direction of the flow results in a reversal of the direction in which the impeller is deflected. Thus the direction of the flow as well as its velocity is indicated. A dial is attached to the impeller by means of a hollow tube through which the upper torsion wire extends. The angular position of the impeller is recorded by photographing the dial at frequent intervals. In any given set of torsion wires the modulus of shear and polar moment of inertia remain constant and the deflection varies directly with the applied torque. The deflection imparted to the torsion wires also varies as the square of the fluid velocity. Further, the velocities represented by any two given deflections hear the following relationships: and Where V = velocity of flow stream and O ;= deflection. This is the basic relationship which is used to calculate the relative velocities represented by a given set of deflections where the velocity represented by any one of the deflection readings is a known quantity. For a given torque, the deflection of the torsion wire varies inversely as the fourth power of the wire diameter. Wire sizes ranging from ,005 in. in diameter to .022 in. in diameter can be used. The range of

Jan 1, 1957

By Clyde Williams

IF you would allow me some liberties, I would restate the title of this talk as "Scientific Research, Our Greatest Resource," because that title would represent more clearly a present-day conception of the metals and minerals situation. It is a subject worthy of careful consideration. Canada and the United States are so similar and interdependent in their national economies that, in the following discussion, examples of conditions in the United States may be interpreted to apply to Canada as well. Moreover, it is a striking fact that the per capita value of mineral production in Canada and the United States in 1940 was almost the same. Therefore, in the consideration of this subject, I have made no attempt to differentiate between the two countries. Consumption of the world's mineral resources in the last few decades. and particularly during World War II, has been so enormous as to require some form of magic to ensure the continued progress of civilization in the face of a diminishing supply of these resources which are so critically essential. As C. K. Leith pointed out, in 1941, indus-

Jan 1, 1947

By ELIHU THOMSON

IN 1877, Professor Thomson delivered at the Franklin Institute, [Philadelphia, five lectures on electricity. The object of the lectures and the demonstrations, which were numerous and many of them original even to the employment of special apparatus constructed by the lecturer, was to show clearly that electricity, of whatever name, was the same., differing only in tension (as it was termed) and in the current flowing, or quantity (the old term), in steadiness or in wave-like character. In those days, the textbooks divided the subject into statical and dynamic electricity, with sub-divisions such as frictional electricity, voltaic electricity, magneto electricity, electromagnetism, thermo electricity, and animal electricity. The well-known Ruhmkorff coil,' or spark coil as it is now called (as when used for the ignition of automobiles), was employed to step, up a battery current to a high-tension discharge which would charge condensers, such as Leyden jars.

Jan 1, 1921