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By G. A. Beiswenger

The application of the law of supply and demand to the sale of crude oil is generally conceded, but the motives underlying the buyer's (refiner's) demands are not always obvious to the seller (producer). In some cases this obscurity has led to the conclusion that the refiner may be unnecessarily particular when he selects one crude and rejects another. This preference, however, is very largely the reflection of the refiner's product demands and the quality of the stocks obtainable from the selected crude. The purpose of this paper is to point out critical characteristics of the major classes of refined products and to show how crudes vary in their suitability for such products. With relatively few exceptions, available processing methods and addition agents make it theoretically possible to produce any type of refined product from any crude source, although it may not be economi-cally sound to do so. The widespread application of thermal cracking for converting higher boiling stocks into gasoline is well known. More recently cracking and refining in the presence of catalysts9 have been developed, as well as various processes for polymerizing lighter hydro-carbons into gasolines having desirable characteristics.6 For several years, selective solvents have been applied commercially to refining inferior quality kerosene, Diesel fuel and lubricating oil distillates .3 Improved methods for refining lubricating oils from crude residua,4 formerly suitable only for fuel, are now in use and a number of special solvent processes are available for dewaxing lubricating oils to low pour point.5 These improved refining methods have been developed not only to meet the demand for improved product quality but also to enable the refiner to obtain quality products from crude sources that would not yield such products by the older refining methods. In many cases, the utilization of these modern refining tools necessi-tates an appreciable expenditure for equipment as well as added manufac-turing costs, and their application therefore must be justified economically. Despite the availability of such tools, the added processing costs involved and yields obtainable may render their application entirely impractical. To illustrate this point, inspections of typical cuts from various crudes

Jan 1, 1940

By H. M. Chance M

The following tables have been compiled from the annual reports of the Inspectors of Mines, to determine the percentages of fatal and non-fatal casualties from roof-falls and explosions of fire-damp. As we cannot assume that every accident has teen recorded by the inspectors ; as many casualties terminating fatally after the lapse of a considerable period, are inevitably recorded as " non-fatal;" and as clerical errors may have crept into the compilation,* the figures of these tables cannot be considered absolutely correct, but the summary is sufficiently reliable to show the features I wish to differentiate. Under the heading " Miscellaneous" are included all accidents not directly attributable to explosions of fire-damp, roof-falls or fails of coal. Prominent among the numerous causes included under this head are premature or delayed explosion of blasts, accidental explosion of powder or cartridges, accidents from mine cam, falls in shafts, machine accidents, sliding of loose coal in pitching breasts, suffoca tion by choke-damp, etc., comprising in all 48 per cent. of the total number of casualties.

Jan 1, 1882

By L. R. Ingersoll, James Fisher, Harry Vivian

The copper mines of the Keweenaw Peninsula in northern Michigan have long been of interest in connection with deep earth-temperature measurements. The extraordinary low geothermal gradient of l° F. in 223.7 ft. announced by Agassiz1 as a result of measurements dating from 1886, although later2 stated as in error, served to focus attention on this region as one offering, because of the great depth of the mines, unusual opportunity along this line. Lane,3 Van Orstrand4 and others have made valuable contributions to this study. Fresh opportunities afforded by the constant deepening of the mines, improvements in the accuracy and reliability of temperature-measuring instruments together with increasing knowledge of the heat conductivities and specific heats of the rocks, led the Michigan College of Mining and Technology in cooperation with some of the mining companies to renew work on this problem. It is planned eventually to complete a survey which will make use of the favorable opportunities for deep rock-temperature measurements presented in these mines. This survey should include the determination of a depth-temperature gradient in both conglomerate and arnygdaloid mines, and also the variations in temperature at the same depth in different geological formations. The first problem has a direct bearing on the question of providing equipment for necessary ventilation with increased depth. The second may show that a relation exists between the natural rock temperature and the mineral content of the formation. The measurements in all cases are to be guided by heat conduction considerations, to the end that they may represent as closely as possible

Jan 1, 1934

By A. M. Lovelace

Introduction One area of engineering utilization of materials in which the requirements are especially rigorous and demanding is that of aerospace systems, including aircraft, helicopters, missiles, and space satellites. Materials used in these systems must reliably perform many critical functions in a broad range of adverse environments. Some of the most critical functions are performed by polymeric nonmetallic materials such as elastomers (rubber), coatings, fibrous materials, and reinforced plastics. These types of polymeric materials have some common characteristics that make them attractive to aerospace system designers: light weight, corrosion resistance, and relative ease and low cost of processing and fabrication. Each type also has its own special characteristics that enable it to perform certain required functions better than other competing materials can (Table 1). The desirable properties of polymeric materials, which in some applications make them the only practical candidates, are partly offset by their principal limitation, which is degradation by exposure to high temperature. [ ]

Jan 1, 1971

By H. M. Chance

Asst. Geologist, Pennsylvania Geological Survey THE following tables have been compiled from the annual reports of the Inspectors of Mines, to determine the percentages of fatal and non-fatal casualties from roof-falls and explosions of fire-damp. As we cannot assume that every accident has been recorded by the inspectors; as many casualties terminating fatally after the lapse of a considerable period, are inevitably recorded as "non-fatal;" and as clerical errors may have crept into the compilation,* the figures of these tables cannot be considered absolutely correct, but the summary is sufficiently reliable to show the features I wish to differentiate. Under the heading a Miscellaneous" are included all accidents not directly attributable to explosions of fire-damp, roof-falls or falls of coal. Prominent among the numerous causes included under this head are premature or delayed explosion of blasts, accidental explosion of powder or cartridges, accidents from mine cars, falls in shafts, machine accidents, sliding of loose coal in pitching breasts, sltffouration by choke-damp, etc., comprising in all 48 per cent of the total number of casualties. * Compiled by Mr. Maxwell Chapman

Jan 1, 1882

By M. R. Meyer, W. T. Walter

A great deal is known, in a qualitative sense, about the performance of CMI EB-36 centrifuges. The manufacturer can give reliable guidance for the proper operation of its centrifuges and can give general estimates of expected product moisture and recovery. Quantitative estimates of the effects of changes in the various operating parameters are more difficult to find. The engineer faced with designing a preparation plant may be without the specific data needed to make decisions. For example, to obtain optimum product moisture when drying 9.5 mm X 595 µm (0.4 in. x 28 mesh) coal the centrifuge manufacturer recommends having no more than 5% -595 µm (-28 mesh) material in the centrifuge feed. They know that more -595 µm (-28 mesh)material in the feed will cause higher product moistures, but they usually cannot quantify the increased moisture or describe the shape of the product moisture versus -595 µm (-28 mesh) in the feed curve. This study was conceived to provide quantitative information on the EB-36 centrifuges, focusing on product moisture, recovery, and size degradation. All of the centrifuges tested were Model EB-36 dryers from Centrifugal and Mechanical Industries Inc. (CMI), with feeds in the nominal 9.5 mm x 595 pm (0.4 in. x 28 mesh) range. These are typical centrifugal dryers in this application, and many were available for testing.

Jan 1, 1984

By Sylvain J. Pirson

The main value of earth magnetic measurements, outside of certain mining problems, resides in the study of deeply buried tectonic phenomena related to regional and local geology. Magnetic surveys are a necessary complement of gravimetric measurements, especially of pendulum surveys. To date, magnetometer prospecting has been used chiefly in the study of sedimentary basins where petroleum structures are associated with the uplifted basement rocks. There are, in the literature, innumerable articles dealing with such surveys as applied to oil geology but few treat of broad geological features related to regional magnetic disturbances of the earth field. An important piece of coordination work has been made by Jean Jungl for the magnetic and gravimetric measurements made in France and their geologic significance. A similar attempt at correlation of the known geology with the anomalies of the vertical component of the earth magnetic field has been made for the United States by George B. Somers2. Taking the magnetic vector as a whole, W. P. Jenny3 made a coordination of magnetism and geology for the main producing oil states of the United States. A more detailed study along the same lines is published by A. Van Weelden4 for southern Oklahoma and northern Texas; in this work magnetic and gravimetric measurements taken at stations as close as one mile apart are compiled and compared to the regional geology of the Ouachita-Amarillo uplifted area. From the literature mentioned, it is evident that reliable interpretation of magnetic' anomalies can be arrived at only when the magnetic stations are numerous and cover the area in a close net of measurements, therefore the works of Somers and Jenny, based on sparsely distributed Government measurements, can be regarded only as preliminary programs indicating lines along which further work should be done, whereas the coordination made by Van Weelden is an example of the contribution to the knowledge of regional geology that can be arrived at by the use of applied geophysics. With the hope that further systematic magnetic measurements will be carried on to solve regional and local geological problems, the author

Jan 1, 1940

By Sylvain J. Pirson

The main value of earth magnetic measurements, outside of certain mining problems, resides in the study of deeply buried tectonic phenomena related to regional and local geology. Magnetic surveys are a necessary complement of gravimetric measurements, especially of pendulum surveys. To date, magnetometer prospecting has been used chiefly in the study of sedimentary basins where petroleum structures are associated with the uplifted basement rocks. There are, in the literature, innumerable articles dealing with such surveys as applied to oil geology but few treat of broad geological features related to regional magnetic disturbances of the earth field. An important piece of coordination work has been made by Jean Jungl for the magnetic and gravimetric measurements made in France and their geologic significance. A similar attempt at correlation of the known geology with the anomalies of the vertical component of the earth magnetic field has been made for the United States by George B. Somers2. Taking the magnetic vector as a whole, W. P. Jenny3 made a coordination of magnetism and geology for the main producing oil states of the United States. A more detailed study along the same lines is published by A. Van Weelden4 for southern Oklahoma and northern Texas; in this work magnetic and gravimetric measurements taken at stations as close as one mile apart are compiled and compared to the regional geology of the Ouachita-Amarillo uplifted area. From the literature mentioned, it is evident that reliable interpretation of magnetic' anomalies can be arrived at only when the magnetic stations are numerous and cover the area in a close net of measurements, therefore the works of Somers and Jenny, based on sparsely distributed Government measurements, can be regarded only as preliminary programs indicating lines along which further work should be done, whereas the coordination made by Van Weelden is an example of the contribution to the knowledge of regional geology that can be arrived at by the use of applied geophysics. With the hope that further systematic magnetic measurements will be carried on to solve regional and local geological problems, the author

Jan 1, 1940

By B. E. Fernow

MINING interests in the Western mountains are very seriously affected by the danger to property and life from destructive snowslides and avalanches. This is a danger which the miner has largely brought upon himself by an improvident stripping of the timber from the mountain slopes, and, therefore, he might be expected to take an interest in the reforestation of the areas thus devastated. A canvass was lately undertaken by the writer to ascertain approximately the extent of the damage suffered from this source, but the difficulty of obtaining reliable data has proved too great to permit, as yet, even an approximation. So much, however, is certain : that the loss of life is considerable, and that much property is destroyed almost every winter. True, neither the number of avalanches, nor their destructiveness, nor the amount of loss compares with what Switzerland experiences. This is due not only to the greater precipitousness of the Alps and to different climatic conditions, but also to the fact that in Switzerland a larger number of settlements is exposed to these dangers. A very complete and interesting official report on the very numerous and destructive avalanches occurring in Switzerland during the season of 1887-1888 has just been published as a contribution to the inquiry, whether and how these dangers can be averted. Peculiar weather-conditions, in addition to heavy falls of snow, were the reasons for the frequency of the phenomenon during that winter. This report records 1094 avalauches, by which 850 houses were destroyed or severely damaged; 84 persons and 752 cattle were buried; traffic on railroads and on highways was greatly interrupted, and the damage to personal property alone was valued at over $100,000. One of these snow-masses covered about half an acre, with a cone 250 feet in height. During the same year in Tyrol the number of avalanches was 3647. Of these 1355 run over permanent beds; that is, they recur annually, so that they are

Jan 1, 1890

By P. W. Ramsey, D. P. Kedzie

INCREASING demand for improved strength-weight ratios made on aircraft structures has resulted in a gradual increase in the tensile strength requirements for steels used in such applications. As the cyclic loads often are more critical than static loads, and the fatigue properties are generally the design criteria, the question arises as to whether an improvement in fatigue properties accompanies the increased tensile strength. The present investigation was undertaken to determine the relationship between fatigue and tensile properties for an aircraft quality steel in the 155 to 280 ksi (1000 psi) tensile strength range, using the Prot method of fatigue testing. Procedure and Results After preliminary work to establish proper heat treating procedures for this heat of aircraft quality electric furnace steel (a Ni-Cr-Mo-V steel," AMS- Prot Fatigue Testing Method—The determination of the endurance limit by the conventional Wohler method can be time-consuming and easily require 20 specimens when statistical variance is to be established. This is also true when endurance limit loads are determined on actual parts or subassem-blies, and the desirability of a reliable accelerated method has been evident for some time. The primary advantage of the Prot method of fatigue testing is in reducing the number of specimens and the time required for each test. Unlike the Wohler method, every Prot specimen tested con- tributes to the determination of the endurance limit, and the authors have been able to duplicate Wohler results obtained with 20 specimens with only half the specimens and a fourth of the total cycles. This new technique for defining the endurance limit was proposed in 1948' by Marcel Prot and consists of progressively increasing cyclic stress until fatigue failure occurs. By varying the load rate, a, a useful relationship is found to exist with failure stress, so that for steel the failure stress appears to

Jan 1, 1958

By R. A. Morse, C. R. Stewart, F. F. Craig

This paper preFents the results of a series of model flow test on a number of large limestone cores, having different pore configurations. For limestone cores having substantially sandstone type porosity, the production characteristics for solution and external gas drives are similar. For cores whose pore spaces were microscopically heterogeneous (i.e., consisted of combinations of solution cavities, matrix. and fissures), the production characteristics lor solution and external gas drives vary widely. The degree of divergence between gas-oil relative permeability relationships calculated from solution or external gas drive tests is an indication of heterogeneity of rock pore structure. The results of water floods on cores depleted by solution gas drive for each of these two general types of limestone porosity are also shown. Generalizations are made on the water flood recovery that could be expected from each of these two types of limestone porosity. The similarity between solution drive field performance and model solution drive performance on cores from the same formation is shown for several cases. This indicate? the feasibility of predetermining limestone field performance from such large core tests. Photomicrographs of plastic-impregnated rock thin sections of the samples tested are presented as an aid in understanding the flow test performances. INTRODUCTION During the past 15 years. reservoir engineers and research workers have developed methods of testing rock and fluid samples and applying the results, through calculation, to allow reasonably satisfactory predictions of oil recoveries and performances to be expected in sandstone oil recervoirs. It has been determined that representative fluid flow data can be obtained on rock samples as small as three-fourths in. in diameter by one in. long in most sandstones. However, little has been accomplished toward the laboratory determination of fluid flow characteristics in limestones. There has been a great deal of speculation as to the influence of variations in pore size, shape, and degree of interconnection upon oil recovery processes, and a great deal of thought has been given to the interpretation of limestone field perfomance. It has been generally recognized that predictions of reservoir performance based on oil displacement tests on small limestone core samples the size of those used for sandstone tests can often be misleading because of the improbability of obtaining a representative sample in such a small core. Obviously, if there are present in the rock, pore openings of the magnitude of 1/16 in., or fractures or solution channels up to one in. or more in length, it will be impossible to cut any sample less than one in. in any dimension which would represent the flow geometry of the gross rock system. In some formations, the individual openings in the rock are of such size that it would be impossible to obtain a good sample of the flow system even in the total core available from conventional-sized well cores. However, by increasing to the maximum the size of the sample used, it should be possible to obtain representative flow data from the majority of limestone reservoir materials which can be used for prediction of future primary production performance or response to be expected from secondary recovery measures. The only alternatives to obtaining good laboratory test data to serve these purposes are extrapolation of primary performance data obtained by partial depletion of a field, or obtaining information from pilot tests. It has been shown previously, and will be demonstrated further by the work reported in this paper, that extrapolation of solution gas drive performance for an estimate of gas injection response can be very misleading in reservoirs of heterogeneous type porosity. Although it cannot be expected that laboratory information can ever eliminate the necessity of small-scale pilot operations, it is expected, as is now the situation with sandstone reservoirs, that laboratory tests should provide reliable information for screening of

Jan 1, 1953

By John Chipman, Theodore B. Winkler

In order to understand more fully the complexities of the reactions occurring between the liquid steel and the slag in the basic open-hearth steelmaking furnace, investigations in this country and. abroad have turned to laboratory equilibrium studies. This paper is one of a series of reports on investigations being conducted at the Massachusetts Institute of Technology. The experimental work was completed early in 1942. The slag systems found in the basic open hearth are very complex, being made up of at least eight major components and as many others whose effect might be classified as minor. The first two papers of the series, by Fetters and Chipman,l,2 as well as the paper by Taylor and Chip-man,3 dealt with the simplest possible slag system that would resemble those found in the basic ope), hearth—the slag system consisting of CaO-MgO2-SiOz-FeO. (Taylor's rotating induction furnace eliminated the necessity of contamination of the slag by MgO.) Having arrived at some reasonable conclusions regarding the physical chemis- try of the reactions between molten iron and the simple slags at equilibrium, the next step was to investigate more complex slag systems. The major purpose of the present investigation was to determine what factors control the distribution of phosphorus between molten iron and the more complex basic slags at equilibrium, and to what extent these factors are influential. The slags used contained CaO, MgO, SiO2, FeO, Fe2O3, P2O6, MnO, Al2O3 and CaF2, but not all of the slag samples contained all of these components at one time. Review of Literature Although a number of interesting papers have been published on the subject of dephosphorization of an iron bath, there are as yet no results from laboratory studies that give thoroughly reliable information on the dephosphorization reaction. Even for the supposedly simple Fe-O-P system involving iron-phosphorus melts and iron oxide-iron phosphate slags, the experimental results are contradictory and no formulas have been established that adequately fit the equilibrium conditions. The Fe-O-P system has been studied by Schackmann and Krings,4 von Samson-Himmelstjerna,6 Oelsen and Maetz,6 Bischof and Maurer,7 Diepschlag and Schürmann,8 and Herty,9 and the results of their investigations appear in Table I. A number of different equilibrium constants and distribution . Ratios

Jan 1, 1947

By Theodore B. Winkler, John Chipman

In order to understand more fully the complexities of the reactions occurring between the liquid steel and the slag in the basic open-hearth steelmaking furnace, investigations in this country and. abroad have turned to laboratory equilibrium studies. This paper is one of a series of reports on investigations being conducted at the Massachusetts Institute of Technology. The experimental work was completed early in 1942. The slag systems found in the basic open hearth are very complex, being made up of at least eight major components and as many others whose effect might be classified as minor. The first two papers of the series, by Fetters and Chipman,l,2 as well as the paper by Taylor and Chip-man,3 dealt with the simplest possible slag system that would resemble those found in the basic ope), hearth—the slag system consisting of CaO-MgO2-SiOz-FeO. (Taylor's rotating induction furnace eliminated the necessity of contamination of the slag by MgO.) Having arrived at some reasonable conclusions regarding the physical chemis- try of the reactions between molten iron and the simple slags at equilibrium, the next step was to investigate more complex slag systems. The major purpose of the present investigation was to determine what factors control the distribution of phosphorus between molten iron and the more complex basic slags at equilibrium, and to what extent these factors are influential. The slags used contained CaO, MgO, SiO2, FeO, Fe2O3, P2O6, MnO, Al2O3 and CaF2, but not all of the slag samples contained all of these components at one time. Review of Literature Although a number of interesting papers have been published on the subject of dephosphorization of an iron bath, there are as yet no results from laboratory studies that give thoroughly reliable information on the dephosphorization reaction. Even for the supposedly simple Fe-O-P system involving iron-phosphorus melts and iron oxide-iron phosphate slags, the experimental results are contradictory and no formulas have been established that adequately fit the equilibrium conditions. The Fe-O-P system has been studied by Schackmann and Krings,4 von Samson-Himmelstjerna,6 Oelsen and Maetz,6 Bischof and Maurer,7 Diepschlag and Schürmann,8 and Herty,9 and the results of their investigations appear in Table I. A number of different equilibrium constants and distribution . Ratios

Jan 1, 1947

By W. T. Lankford, Low J. R., Gensamer M.

The problem of sheet metal formability is one which has received a vast amount of attention during recent years. In spite of the great amount of study and experimental work which has been devoted to this problem, many of its fundamental aspects are still not well understood. No generally satisfactory test has been developed which is capable of providing a reasonably adequate evaluation of sheet metal formability, particularly in borderline cases. Anomalies persistently arise in which a lot of supposedly satisfactory material exhibits excessive breakage when formed. This lack of suitable technological tests greatly hinders the design of new parts and the substitution of new materials in parts of existing design, frequently necessitating considerable costly trial and error experimentation on an actual production basis. When, at the beginning of World War 11, it became apparent that mass production methods of forming would bc required in the aircraft industry if the large numbers of military aircraft needed were to be supplied, renewed attention was focussed on the problem of sheet metal formability. It was widely recognized that the formability requirements placed on sheet metals had been steadily increasing in severity through the years, especially as greater and greater emphasis was placed on streamlined designs with the resultant freer application of doubly curved surfaces. The recent advent of several new high strength aluminum alloys of more limited formability than some of the older alloys also served to emphasize the need for new approaches to the problem. It seemed evident that progress in the technology of sheet metal forming would depend to a great extent on the development of more reliable criteria for the evaluation of formability. Although the problem is admittedly very complex, the most logical approach appeared to be through studies of the fundamental material properties of sheet metals, especially under complex stress conditions simulating those prevailing in actual forming operations. Most previous investigations have failed to make full use of existing knowledge of fundamental material properties, and in many instances have attempted correlations with properties which are now recognized as being ambiguous in nature. This investigation was undertaken, therefore, with the aim of developing methods for the study of the flow and fracture of sheet meta1s under combined stresses, and of making use of such methods as might be developed in

Jan 1, 1947

By Low J. R., Gensamer M., W. T. Lankford

The problem of sheet metal formability is one which has received a vast amount of attention during recent years. In spite of the great amount of study and experimental work which has been devoted to this problem, many of its fundamental aspects are still not well understood. No generally satisfactory test has been developed which is capable of providing a reasonably adequate evaluation of sheet metal formability, particularly in borderline cases. Anomalies persistently arise in which a lot of supposedly satisfactory material exhibits excessive breakage when formed. This lack of suitable technological tests greatly hinders the design of new parts and the substitution of new materials in parts of existing design, frequently necessitating considerable costly trial and error experimentation on an actual production basis. When, at the beginning of World War 11, it became apparent that mass production methods of forming would bc required in the aircraft industry if the large numbers of military aircraft needed were to be supplied, renewed attention was focussed on the problem of sheet metal formability. It was widely recognized that the formability requirements placed on sheet metals had been steadily increasing in severity through the years, especially as greater and greater emphasis was placed on streamlined designs with the resultant freer application of doubly curved surfaces. The recent advent of several new high strength aluminum alloys of more limited formability than some of the older alloys also served to emphasize the need for new approaches to the problem. It seemed evident that progress in the technology of sheet metal forming would depend to a great extent on the development of more reliable criteria for the evaluation of formability. Although the problem is admittedly very complex, the most logical approach appeared to be through studies of the fundamental material properties of sheet metals, especially under complex stress conditions simulating those prevailing in actual forming operations. Most previous investigations have failed to make full use of existing knowledge of fundamental material properties, and in many instances have attempted correlations with properties which are now recognized as being ambiguous in nature. This investigation was undertaken, therefore, with the aim of developing methods for the study of the flow and fracture of sheet meta1s under combined stresses, and of making use of such methods as might be developed in

Jan 1, 1947

By J. Lohrenz, C. R. Clark, B. G. Bray

Procedures to calculate the viscosities of in situ reservoir gases and liquids from their composition have been developed and evaluated. Given a composition expressed in methane through heptanes-plus, hydrogen sulfide, nitrogen and carbon dioxide together with the molecular weight and specific gravity of the heptanes-plus fraction, the procedures are capable of calculating the viscosity of the gas or liquid at the desired temperature and pressure. The procedure for reservoir liquids was developed using the residual viscosity concept and the theory of corresponding states, and was evaluated by comparing experimental and calculated results for 260 different reservoir oils ranging from black to highly volatile. The average absolute deviation was 16 per cent. This is the first known procedure for calculating the viscosity of reservoir liquids from their compositions as normally available, i.e., including the heptanes-plus fraction. The procedure for reservoir gases uses a sequence of previously published correlations. Evaluation of the procedure was accomplished by comparison of 300 calculated and experimental viscosities for high-pressure gar mixtures in the literature. The average absolute deviation was 4 per cent. The calculations are useful for (I) determining viscosities in compositional material balance computations and (2) predicting the viscosity decrease which occurs when gases, LPG, or carbon dioxide dissolve in reservoir oils. INTRODUCTION Methods to predict viscosities of reservoir fluids from the normally available field-measured variables have been presented. Beal,1 Standing,2 and Chew and Connally3 orrelated oil viscosities with temperature, pressure, oil gravity and gas-oil ratio. Carr, Kobayashi, and Burrows4 and Katz et al.5 have presented correlations for reservoir gas viscosities as a function of temperature, pressure and gas gravity. Lie all intensive physical properties, viscosity is completely described by the following function: Eq. 1 simply states that viscosity is a function of pressure, temperature and composition. These previous correlations1- hay be viewed as modifications of Eq. 1, wherein one assumes more simple functions may be used. The assumptions are practical, because the composition is frequently not known. Further, the assumptions are sufficiently valid so that these correlations are frequently used for reservoir engineering computations. In compositional material balance"' computations, the compositions of the reservoir gases and oils are known. The calculation of the viscosities of these fluids using this composition information is required for a true and complete compositional material balance. For reservoir gases, Carr, Kobayashi and Burrows4 have presented a suitable compositional correlation. For reservoir oils, no correlation is available, and data from reservoir fluid analyses have been used7-9 for compositional material balance calculations.* From a theoretical point of view, this is entirely invalid. The reservoir fluid analysis, whether flash, differential, or other process, does not duplicate the compositions which occur during the actual reservoir depletion process, therefore the viscosities measured during reservoir fluid analysis are not those which occur in the reservoir. From a practical point of view, the "error" of using viscosities from reservoir fluid analysis is of varying and unknown significance. One can say qualitatively that the error is greatest where compositional effects are greatest, i.e., for volatile oil and gas condensate reservoirs and pressure maintenance operations. The first requirement to obtain a quantitative estimate of the significance of the error is to develop a reliable compositional correlation for the viscmities of reservoir oils. No such correlation has been available. Consistent with this requirement, the objective of this study was to develop a procedure to predict the viscosity of reservoir fluids from their compositions. Normally, the compositions of reservoir fluids are available expressed as mole fractions of hydrogen sulfide, nitrogen, carbon dioxide and the hydrocarbons methane through the heptane-plus fraction, with the average molecular weight and specific gravity of the latter. The final correlation was to use the composition in this form. While the more challenging objective of the study was the development of a correlation for the viscosities of reservoir oils, the viscosities of reservoir gases were also studied. The end result of the study was a procedure to calculate the viscosities of reservoir gases and liquids suitable

Jan 1, 1965

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, JR., Chairman EDGAR RICKARD, Vice-Chairman D. M LIDDELL, Secretary, 7 Wall St., New. York, N. Y C. A. BOHN, Treasurer JOHN V. N. DORR _ LEWIS W FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman - JAMES G. CARLETON, Vice-Chairman E. E. BUGBEE Secretary-Treasurer, Mass. Inst. of Technology, Cambridge, Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. S. S. FOWLER, Chairman J. C. HAAS, Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer. P. O. Drawer 2154, Spokane, Wash. W. H. LINNEY

Jan 2, 1918

By George Wendell

THE fact that a symposium on pyrometry is being held under the auspices of the American Institute of Mining and Metallurgical Engineers may very properly be taken as a recognition of the importance of temperature measurements and control in production and in the industries, and of the need for instruction in pyrometry in our schools of engineering. Though there may be general agreement as to the need of some instruction along this line, there will undoubtedly be divergence of opinion as to the amount of time that can be allowed to such instruction, as well as to its character. Those who have given little attention to the complexity of high-temperature measurements will be apt to think that a few simple experiments are all that is required. They fail to distinguish between the artisan, who merely has to learn how to use any piece of apparatus that is installed, and the technically trained man, who must be prepared to assume the responsibility for the supervision and maintenance of the pyrometric equipment, for the calibration of the instruments, and for the solution of any temperature problems that arise. In approaching this subject two questions present themselves: What should be the character of the instruction in pyrometry in an engineering school, and what can be expected of the students who have had this instruction? In brief, it may be said that the aims of a course in pyrometry should be to give: (1) A thorough grounding in the fundamental principles of thermoelectric, resistance, radiation, and optical pyrometry, and of liquid and gas thermometry; (2) practical instruction in the calibration of pyrometers; (3) acquaintance with the errors that are likely to arise and the precautions that must be observed in practice; (4) information regarding the limitations of the various classes of instruments, their relative reliability, and the accuracy attainable with them at different temperatures; (5) acquaintance with the commercial instruments on the market, their construction and relative merits; (6) a knowledge of the chief sources of information relating to the measurement of high and low temperatures. To sum up, the aim should be to turn out resourceful young men familiar with the leading instruments on the

Jan 9, 1919

By A. W. Fahrenwald

THE absolute efficiency of crushing and grinding in a ball mill is not known. A number of investigators have made calculations to this end and have presented efficiency figures. Two factors have prompted further investigation of this subject: (1) the unbelievably low magnitude of the values offered, and (2) a desire to obtain, if possible, true relationships between the relative efficiencies of a ball mill operating under varying conditions. A useful forward step in the study of mill efficiency was made when Martin1 and Gross and Zimmerley2 proved the correctness of Rittinger's law, and incidentally the incorrectness of the so-called Kick law, and when Gross and Zimmerley3 determined and gave surface values for Tyler sieve-sized quartz. These data are probably accurate throughout the range of the sieve scale, but on -400 mesh (which is the finest sieve available), the surface data, as obtained by the hydrofluoric acid disso-lution method, are of doubtful reliability. Any inaccuracy existing in surface determinations of -400-mesh material, especially when comparing runs in which varying quantities of this product are formed, will cause the resulting relative mill efficiency values to be distorted. Moreover, knowing surface accurately, the efficiency calculations require a surface energy figure. Two such figures are to be found in literature, one by Edser4 and one by Martin.5 Edser's surface energy

Jan 1, 1931

This report presents the comments of members of the Institute's Sub-committee on Physics of Mine Ventilation on the proposals of a special committee of the Institute of Mining Engineers (London). This report is as follows: THEORY OF MINE VENTILATION Abstract of a report submitted June 16, 1925, to the Council of The Institution of Mining Engineers by a Special Committee Laws of Flow of Aib The law of flow of air in mine galleries is, at present, expressed by two formulas differing slightly in shape but both derived from the original hydraulic formulas of Chezy and others. These formulas are: The Atlcinson Formula.—Pa = KsV2, which in transformation becomes a3 where P = pressure producing flow; K = coefficient of friction; s = surface of the mine galleries; V = velocity of flow; Q = rate of flow; a = area of mine galleries. This formula is especially applicable to mine galleries, but is unwieldy in application, as in many problems we are dealing with changes produced in the same set of airways when K, s, and a are assumed not to change, and the only variables are P and Q. Great uncertainty prevails as to the exact values to be assigned to the coefficient K in different types of airway, as different workers have given widely differing values. This formula assumes: (I) That resistance to flow is independent of the pressure within the gallery. (2) That changes in volume within the limits of pressure ordinarily met with may be neglected. (3) That changes in density and viscosity and mode of flow of the air may be neglected. (4) That the coefficient K is a constant. (5) That P is proportional to the square of the velocity. We cannot find any reliable experimental work leading us to conclude how far these assumptions are justifiable in mining practice. Equivalent Orifice Formula.—The fundamental form of this formula is Q = ~nA.\/2~11

Jan 1, 1927