Search Documents

By W. P. Sykes

Seven years ago, Dr. S. L. Hoytl presented a masterful discussion of the hard metal carbides and cemented tungsten carbide. His lecture summarized most of the data then available in the field; many of the details relating to the production, properties and structure of cemented tungsten carbide had never been previously published, for, in fact, this information was only then being acquired. During the intervening years, the cemented carbides have assumed a place of real importance in the commercial field, with an ever widening variety of applications due to constant improvement in the control of production technique and the unremitting search for new compositions that might better the performance of the alloys in one or another type of service. The most recent summary of production methods, properties and guides for the successful application of the cemented carbides appears in the 1936 edition of the Metals Handbook. Of necessity, much detailed information relating to structures and physical properties is not included in such a summary, and it is with such details that the present discussion is concerned. Steps in Preparation While the past 25 years have contributed a valuable store of working knowledge in the field of powder metallurgy, many of the process controls are derived entirely from experience and are not as yet finally explained by a specific physical or chemical phenomenon. For most of the cemented carbides such difficulties are aggravated by our lack of knowledge not only of the complex alloy systems involved, but also by the possible changes in structure and even in composition which may accompany variations in temperature, heating time, and furnace atmospheres. The principal steps in the preparation of these cemented carbide alloys are fairly well known, but to supply a foundation for discussion these steps are briefly outlined as follows : 1. Formation of the metal carbide in the form of powder by heating a mixture of carbon and the metal powder or oxide for several

Jan 1, 1938

By W. P. Sykes

Seven years ago, Dr. S. L. Hoytl presented a masterful discussion of the hard metal carbides and cemented tungsten carbide. His lecture summarized most of the data then available in the field; many of the details relating to the production, properties and structure of cemented tungsten carbide had never been previously published, for, in fact, this information was only then being acquired. During the intervening years, the cemented carbides have assumed a place of real importance in the commercial field, with an ever widening variety of applications due to constant improvement in the control of production technique and the unremitting search for new compositions that might better the performance of the alloys in one or another type of service. The most recent summary of production methods, properties and guides for the successful application of the cemented carbides appears in the 1936 edition of the Metals Handbook. Of necessity, much detailed information relating to structures and physical properties is not included in such a summary, and it is with such details that the present discussion is concerned. Steps in Preparation While the past 25 years have contributed a valuable store of working knowledge in the field of powder metallurgy, many of the process controls are derived entirely from experience and are not as yet finally explained by a specific physical or chemical phenomenon. For most of the cemented carbides such difficulties are aggravated by our lack of knowledge not only of the complex alloy systems involved, but also by the possible changes in structure and even in composition which may accompany variations in temperature, heating time, and furnace atmospheres. The principal steps in the preparation of these cemented carbide alloys are fairly well known, but to supply a foundation for discussion these steps are briefly outlined as follows : 1. Formation of the metal carbide in the form of powder by heating a mixture of carbon and the metal powder or oxide for several

Jan 1, 1938

By W. P. Sykes

SEVEN years ago, Dr. S. L. Hoyt1 presented a masterful discussion of the hard metal carbides and cemented tungsten carbide. His lecture summarized most of the data then available in the field; many of the details relating to the production, properties and structure of cemented tungsten carbide had never been previously published, for, in fact, this information was only then being acquired. During the intervening years, the cemented carbides have assumed a place of real importance in the commercial field, with an ever widening variety of applications due to constant improvement in the control of production technique and the unremitting search for new compositions that might better the performance of the alloys in one or another type of service. The most recent summary of production methods, properties and guides for the successful application of the cemented carbides appears in the 1936 edition of the Metals Handbook. Of necessity, much detailed information relating to structures and physical properties is not included in such a summary, and it is with such details that the present discussion is concerned. STEPS IN PREPARATION While the past 25 years have contributed a valuable store of working knowledge in the field of powder metallurgy, many of the process controls are derived entirely from experience and are not as yet finally explained by a specific physical or chemical phenomenon. For most of the cemented carbides such difficulties are aggravated by our lack of knowledge not only of the complex alloy systems involved, but also by the possible changes in structure and even in composition which may accompany variations in temperature, heating time, and furnace atmospheres. The principal steps in the preparation of these cemented carbide alloys are fairly well known, but to supply a foundation for discussion these steps are briefly outlined as follows: 1. Formation of the metal carbide in the form of powder by heating a mixture of carbon and the metal powder or oxide for several

Jan 1, 1938

By G. Willard Quick

FAILURES in railroad rails have been of vital concern to engineers; railroad executives, rail manufacturers and the general public for years. Failures from transverse fissures originating from internal nuclei have received particular attention in the past 20 years. Dr. J. E. Howard first reported this type of failure in 1911, as being responsible for a wreck-on the Lehigh Valley R. R. in which several lives were lost. Since then many transverse fissures have been found. In 1919, Waring and Hofammann1 etched longitudinal sections of rails in hot acid and found cracks extending both longitudinally and transversely in certain used rails as well as in some new rails.. Since then it has been thought by many that these "shatter" cracks are the nuclei from which transverse fissures subsequently develop in service. Methods for reducing the rate of cooling rails on the hot. bed have been devised to decrease the temperature gradient and consequently the stress gradient in the rails. A study of the tensile properties of rails at elevated temperatures was made by Freeman and Quick,2 who investigated the properties at temperatures through which rails pass on the cooling bed after leaving the hot saw. In their investigation a special study was made of the ductility of the steels in the temperature range 400° to 700° C. In this temperature range it was found that certain rail and other steels showed a marked decrease in elongation and reduction of area. The phenomenon was called "secondary brittleness" and the temperature range the "secondary brittle range." A tentative explanation was presented that internal failure such as "shatter cracks" and "hair cracks" in rails are the result of thermal stresses developed in the steel structure while cooling through the secondary brittle range. The investigation showed that the magnitude of the phenomenon varies for different heats, but that it did not differ for specimens from different ingots or for different rails in a particular ingot. It was also shown that annealing rail steel at a temperature either above or below the critical

Jan 1, 1932

By C. W. Andrews

The various methods of by-product coke-manufacture have been quite thoroughly discussed in a number of papers recently published, and I think it would possibly be of interest and value to discuss the growth and probable future of the byproduct coke industry, rather than details of manufacture. The first by-product coke-plant in the United States, consisting of 12 ovens, was put in operation at Syracuse in January, 1893. This installation was followed by one at Johnstown, Pa., in 1895; one at Dunbar, in 1896, and one at Glassport, in 1897. The plant at Syracuse was primarily intended to supply the owners with ammonia for their alkali-works. At Glassport, for the first time, gas was sold for illuminating purposes, although it was mixed with water-gas to make it marketable. The New England Coke & Gas Co. started the plant in Boston in 1899, which was destined to change the whole trend of the establishment of by-product plants, since it manufactured for the first time illuminating-gas suitable for sale without enrichment. This was accomplished by dividing the gas on the battery into two portions. One portion, consisting of the richer part of the gas, was saved for sale, while the remaining, or leaner, portion was used in the battery. This idea was originated by Dr. Schniewind, of the United Coke & Gas Co. The coke was used for domestic, industrial, and locomotive fuel, as its sulphur-content was too high to make it suitable for use in the foundry. The successful operation of this plant led to the building of additional plants at points where the production of illuminating-gas could be sold to advantage and where there was a fair market for the coke-output. The following list of illuminating-gas plants in order of construction will give a good idea of the rapid growth of this method of combined gas- and coke-manufacture: Hamilton, Ohio; Detroit, Mich.; Camden, N. J.; Baltimore, Md.; Chester, Pa.; Milwaukee, Wis.; Duluth, Minn.; Geneva, N. Y.; Chicago, Ill.; Indianapolis, Ind. In addition to these there are now under construction plants at Muncie, Ind.; Joliet, Ill., and Waukegan, Ill., all of which will produce illuminating-gas and metallurgical coke.

Jan 1, 1913

By AIME AIME

FRIEND recently remarked that the career of Scott Turner is characterized by Work and Wild -A Ducks. To these might be added Accomplishment and Persistent Fishing. All of these elements are manifestations of his character. The diversions-hunting and fishing-are in the nature of the proverbial trolley conductor's holiday, for many of Turner's years have been spent in the outdoors, often in distant lands, as in Spitzbergen, where the ducks pictured below were bagged. The election of Scott Turner to the presidency of the Institute marks the culmination of a quarter century of membership, during the last two years of which he has been vice-president. He was born at Lansing, Mich., on July 31, 1880, and received his A.B. at the University of Michigan in 1902, with a B.S. and E.M. at the Michigan College of Mines in 1904. Since then he has been granted two honorary degrees, D.Sc. from the Colorado School of Mines, and D.Eng. from the University of Michigan, but he still prefers to be called "Scott" rather than "Doctor." Government service was not a new experience for Turner when he was appointed Director of the U. S. Bureau of Mines by Secretary Hoover in 1925, for his first employment after graduation was as Field Assistant in the U. S. Geological Survey in Oregon and Idaho. This was followed by work in Tombstone, Ariz.; then his first foreign engagement in 1905-6 as superintendent of the San Pablo Gold Mining Co. in Panama. Various field experiences followed, though there was an interlude in work of a kind that few mining engineers ever experience. This was in technical journalism, for in 1906 he was

Jan 1, 1932

By W. S. Ayres

BACK in the early nineties the old Dickerson iron mine in Morris county, N. J., was operated by a vertical shaft 850 ft. deep and by a continuing slope for more than 1000 ft. more 011 an incline of 65", together making the vertical depth about 1800 ft. I was then the general superintendent there. This mine, named for a former governor of New Jersey, had been worked more or less continuously from long before the American Revolution and up to this particular time. The pumping equipment was of the old-time Cornish type, with its long pump-rods running down the vertical shaft and the slope to the sump at its bottom. It was operated by a large flywheel engine in the engine room and all angles were turned by the usual bobs. Saturday was the day fixed for lowering the "suction" into the deepened sump at the bottom of the advancing slope. The mine foreman had gone down with the morning shift to superintend this very vital and particular work, which consisted not only of lowering the "suction" into the sump immediately after the pump had been stopped, but of securing it to the rock and putting in the added sections of column-pipe and of tightening up the numerous bolts at their joints, all before the water rose to the point of working. At an appointed time during the forenoon I had agreed to go down into the mine and join the mine foreman in consultation over any difficulties that might have arisen. At the time agreed I went down by the cage to the bottom of the vertical 850-ft. shaft, and then by ladders down the slope for over 1000 ft. more.

Jan 1, 1930

By Edmund Newton

The steel industry of the United States has depended in the past almost wholly upon imports for its supplies of manganese. Many of the important domestic sources yield ores leaner in their natural condition than the foreign ores the steel industry. has been accustomed to use. To make them available, therefore, either the ores must be concentrated or the practice of the steel industry modified. Roughly 25,000 T. annually of high-grade manganese ores are used for dry batteries for chemical purpose, and in other ways; while approximately 750,000 T. are required for making steel. , By present practice, every ton of steel takes an average of about 14 lb. (1.8 kg.) of metallic manganese. This is generally added to the steel in the form of an alloy, the standard alloys being the 80-per cent. ferro-manganese and the 20-per cent. spiegeleisen, During the year 1917, 286,000 T. of ferromanganese and 193,291 T. of spiegeleisen were made in this country, the former largely from imported ores; and 45,381 T. of ferromanganese. was imported. The metallic manganese represented by these alloys was 304,000 T., the product of roughly 800,000 T. of high-grade ore and 345,000 T. of low-grade ore. Manganese Deposits in the United States Before the war manganese ore was mined in relatively small quantities in the Appalachian region, including Virginia, Tennessee and Georgia, and in Arkansas, but owing to the increase in prices during the past three years manganese mining has been undertaken also in Montana, California, Arizona, New Mexico, Nevada, Utah, and Minnesota. From data now available it appears that in this country deposits of high-grade manganese ores are usually small, while materials lower in manganese and higher in iron occur in appreciable quantities. Our total quantity of manganese-bearing material is relatively large, but on

Jan 1, 1920

By Thomas Fraser, H. F. Yancey

BefoRe a new coal-washing plant is installed, or an existing washery is remodelled and improved, considerable experimental work on the coal to be washed should be done. A thorough examination of a coal, to determine whether it can be washed successfully and the best and most economical process for securing a satisfactory grade of washed coal, calls for mine sampling, analytical work, and experimental coal-washing tests which may require several months' time and the expenditure of considerable money. Having collected the required data on the characteristics of the coal and the results secured with different types of machines under different sets of conditions, it is necessary to decide what method of treatment should be used. The interpretation of the experimental data is no small part of the problem. The first step in the investigative work is to determine from the characteristics of the coal and the manner of occurrence of the impurities whether it is possible to separate the dirt from the coal and produce a washed coal of the required quality. Then it is necessary to select the type of washer or the system of treatment that will produce the greatest amount of washed coal of this grade for the least cost. To secure this information, tests may be made at laboratories operated by consulting or contracting engineers, at the testing plants of machinery manufacturers, at commercial washeries, or in an experimental washery erected on the site of the proposed plant. Such tests will produce figures in which every factor, including analyses of raw coal and washed coal and yield of washed coal, may vary widely. To reduce these results to a common basis for comparison is very difficult. A number of plans

Jan 1, 1923

By Thomas Fraser, H. F. Yancey

BefoRe a new coal-washing plant is installed, or an existing washery is remodelled and improved, considerable experimental work on the coal to be washed should be done. A thorough examination of a coal, to determine whether it can be washed successfully and the best and most economical process for securing a satisfactory grade of washed coal, calls for mine sampling, analytical work, and experimental coal-washing tests which may require several months' time and the expenditure of considerable money. Having collected the required data on the characteristics of the coal and the results secured with different types of machines under different sets of conditions, it is necessary to decide what method of treatment should be used. The interpretation of the experimental data is no small part of the problem. The first step in the investigative work is to determine from the characteristics of the coal and the manner of occurrence of the impurities whether it is possible to separate the dirt from the coal and produce a washed coal of the required quality. Then it is necessary to select the type of washer or the system of treatment that will produce the greatest amount of washed coal of this grade for the least cost. To secure this information, tests may be made at laboratories operated by consulting or contracting engineers, at the testing plants of machinery manufacturers, at commercial washeries, or in an experimental washery erected on the site of the proposed plant. Such tests will produce figures in which every factor, including analyses of raw coal and washed coal and yield of washed coal, may vary widely. To reduce these results to a common basis for comparison is very difficult. A number of plans

Jan 1, 1923

By Henry M. Howe

The brilliant and very original matter in Professor Jeffries' discussion† should rank not only as an independent paper, but as a most important one. In particular, the explanation which it gives of the remarkable Sauveur phenomenon, over which so many of us have puzzled long and hard, is so clear, complete, and cogent as to go far toward establishing Professor Jeffries' hypothesis. The very leatures of Professor Sauveur's photographs which fit this hypothesis so exactly are reproduced in Chap-pell's photographs of steel coarsened under somewhat different conditions.' The ideas developed by these discoveries are so novel that convenicnce of language seems to call for new conventional terms for expressing them. In what follows here I propose certain terms for this end, for criticism and improvement, and I attempt to generalize from Professor Jeffries' hypotheses. Generally speaking, a given set of grains which undergo no growth in the cold will, when the temperature is raised progrcssively, start to grow on reaching a certain temperature, and will continue growing at all higher temperatures. The "germinative" temperature is that at which growth begins, quite as the conditions which cause a seed to grow are "germinative." We have then an inert temperature range below the germinative temperature, and a growth range above it, the germinative temperature being the limit between these two ranges. So, too, a germinant grain is one which is at its germinative temperature, and hence beginning to grow, while inert grains are those below their own germinative temperature, and the term "growing grains" includes those which are germinant and those which are above their germinative temperature. These last could be called " supergerminant" if the distinction should be needed. "Germinative temperature" seems better than "critical temperature

Jan 1, 1917

By Albert Williams

A large proportion of the work performed in wet-crushing silver mills is devoted to the handling and re-handling of pulp between the battery and the pans. There seems to be no generally applicable substitute for the settling-tanks, and in the present system of constructing mills the tanks involve an amount of labor which may be regarded as disproportionate and unnecessary, in view of the automatic improvements which have been introduced in other directions. This diffculty has been met, however, by Boss's continuous process, in which the pulp flows directly from the mortars to the first of a series of constantly working overflow-pans. This method has been adopted at the Noonday mill, Bodie, California; the Harshaw, Arizona; the Sierra Grande, New Mexico ; and the Prietas, Sonora. The continuous process, while giving excellent results with special ores, and under peculiar local conditions (such as a deficiency in water supply), is not, I believe, claimed to be available for all raw-amalgamating mills, notwithstanding its well-merited popularity for certain work. Some trouble has been experienced from the tendency to concentration in the pans, though this can be avoided by skilful manipulation. It has also the disadvantage inherent in combinations of distinct operations ; it requires a very nice adjustment of the water supply to obtain full battery efficiency without running the pans too thin, though the latter defect is partially compensated for by the gradual thickening of the pulp as it proceeds through the series of pans. The objection is similar to that which holds in a parallel duplex process, that of combining roasting and smelting in a single furnace, where each operation is injuriously affected by the necessity of fitting it in with another and entirely different one.

Jan 1, 1883

THE TRANSACTIONS of the Institute for the early years display but Little interest in physical metallurgy-indeed, it is striking how thoroughly process metallurgy absorbed attention until quite recent years. The first volume carries no article that can be strictly described as physical metallurgy, unless one on the rolling and hammering of ingots be doubtfully so described. Nor does the second volume contribute more the interest then was in mining, and in production methods, both ferrous and nonferrous, with much attention to the new methods of making steel. The third volume records papers on: the condition of carbon in gray and white iron, a paper devoted to chemical rather than microscopic analysis; the annealing of spiegeleisen; phosphorus and carbon in iron and steel, similarly chemical. Much attention was given, and continued to be given for years, to the manufacture and behavior of rails. The question of the nature of steel appeared early (Vol. 11)-What is Steel, by A. L. Holley-where arguments on nomenclature were already active; and Holley also bemoans, in modern spirit, the Inadequate Union of Engineering Science and Art; Pearse wrote on cast iron for guns (reflecting again the ironic beneficence of war in metallurgy), and said that Captain Walbach was the first to insist on chemical analysis of gun irons; he quotes Major Wade's study of comparative hardness, using penetration hardness measurements (Brinell was to come later), and quotes the important Reports on the Strength and Other Properties of Metals for Cannon, by H. C. Baird, Philadelphia, 1855, in which the advanced state of tensile testing at the time is shown. Hewitt, in Vol V, comments upon the function played by technical schools and technical societies upon the growth of metal-

Jan 1, 1948

To the members of the A. I. M. E., who have given much and risked all to fight "Over There" with pick, or gun, or brain, and to the members who have chosen the sometimes more self-denying duty of remaining at home to help produce metals for fighters: Your experience in foreign lands has bred in you that spirit of internationalism which will soon be infused into every corner of our country by virile lads thrilling from a great experience in an old, yet new, land over the seas. To them the East will not seem as far from the West as it was, nor the North from the South. Sectional jealousies will seen despicable to one who has fought for a great ideal shoulder to shoulder with real men of other nations. And they who have willingly sacrificed much on the altar of service will have little patience with an egotist, be he laborer, tradesman, capitalist or engineer. The problems which peace brings to us are more difficult than those of war and their solution requires not only cool heads, tolerance, and wise judgment, but the "getting together" of sections and classes and individuals. The triumph of justice over individualism, represented by the draft law, must be repeated, for there are "slackers" in peace Is well as in war, and the spirit of self-denial expressed in response to Liberty Loans, Red Cross, and Welfare drives and Food Administration appeals must live. We have only just begun to learn how to serve. It is often claimed by our members that the engineer is not given, in the community at large, the recognition which his training should merit; that his reward is not as great nor his service as welcome as it should be. Public service is generally assumed to be a logical activity for a lawyer,

Jan 12, 1918

By Clarence Zener

Theoretical considerations by one of the authors have ledl to the prediction that the dynamic internal friction of annealed metals has a broad maximum at a certain grain size. This prediction they have verified2 for alpha brass. In the present paper the theory is extended to include the precise manner in which the internal friction varies with grain size on either side of the maximum. New experimental data are presented to test this extended theory. The physical basis for the type of internal friction that is being investigated lies in the interplay between stress and temperature. Just as local fluctuations in temperature give rise to local fluctuations in stress, so likewise fluctuations in stress give rise to fluctuations in temperature. But temperature gradients give rise to necessarily irreversible thermal currents, and hence to internal friction. The theory for this type of internal friction has been developed quantitatively,³ and has been experimentally verified,4,5 for the particularly simple case of the transverse thermal currents accompanying transverse vibrations. Of more fundamental importance are the intercrystalline thermal currents accompanying all types of vibration. The variation in stress across grain boundaries arises from the elastic anisotropy and at least partial random orientation of the individual crystallites. An exact quantitative treatment of the internal friction due to these thermal currents is of course out of the question. However, much information can be obtained from general arguments.1,6 Thus when the frequency of vibration f is low, or when the grain size d is small, adjacent grains remain nearly in thermal equilibrium, and vibration proceeds isothermally with little internal friction. Again, when the frequency is high, or the grain size large, the heat flow per cycle is small, the vibration proceeds adiabatically with little internal friction. The internal friction will become a maximum in the transition region. The degree of adiabatic-

Jan 1, 1940

By Clarence Zener

Theoretical considerations by one of the authors have ledl to the prediction that the dynamic internal friction of annealed metals has a broad maximum at a certain grain size. This prediction they have verified2 for alpha brass. In the present paper the theory is extended to include the precise manner in which the internal friction varies with grain size on either side of the maximum. New experimental data are presented to test this extended theory. The physical basis for the type of internal friction that is being investigated lies in the interplay between stress and temperature. Just as local fluctuations in temperature give rise to local fluctuations in stress, so likewise fluctuations in stress give rise to fluctuations in temperature. But temperature gradients give rise to necessarily irreversible thermal currents, and hence to internal friction. The theory for this type of internal friction has been developed quantitatively,³ and has been experimentally verified,4,5 for the particularly simple case of the transverse thermal currents accompanying transverse vibrations. Of more fundamental importance are the intercrystalline thermal currents accompanying all types of vibration. The variation in stress across grain boundaries arises from the elastic anisotropy and at least partial random orientation of the individual crystallites. An exact quantitative treatment of the internal friction due to these thermal currents is of course out of the question. However, much information can be obtained from general arguments.1,6 Thus when the frequency of vibration f is low, or when the grain size d is small, adjacent grains remain nearly in thermal equilibrium, and vibration proceeds isothermally with little internal friction. Again, when the frequency is high, or the grain size large, the heat flow per cycle is small, the vibration proceeds adiabatically with little internal friction. The internal friction will become a maximum in the transition region. The degree of adiabatic-

Jan 1, 1940

By W. M. Weigel

THE rapid advance, during recent years, in the manufacture of articles that have been in common use for generations and the development of new materials entering into appliances and devices unheard of fifty years ago, have created a demand for some of the more common non-metallic minerals. To supply this demand there has quietly developed a branch of the mining industry of which little is known by most mining engineers the mineral-filler industry. In this paper, and generally in the trade, the term mineral filler is applied to a mineral used, in its natural state after mechanical preparation only (such as. grinding, milling and washing), without undergoing any chemical change and without exerting any chemical action on the substance with which it is incorporated. The consumption of mineral fillers is confined chiefly to large manufacturing centers in the eastern and northern states. Where available, materials originating near the place of consumption are used, as most fillers bring a comparatively low price and, frequently, the freight may equal the cost of the finished filler at the mine. The southern states have abundant deposits of non-metallic minerals suitable for fillers, which supply the manufacturing industries in adjacent states. Many of these deposits are equal to, or superior, in quality to those mined in the north, but they can not compete with them because of the freight rates. The mineral-filler industry has felt the present depression, but it has suffered less than most mining industries for as a rule the mills are simple, the overhead expenses are low, and the labor is entirely local and can revert to farm work when the plant closes down. Many other deposits in the southern district will undoubtedly be developed when business. revives and freight rates are adjusted.

Jan 2, 1922

By Howard S. Bryant

The year 1928 has recently.passed from the picture and it is at this time that the various divisions of the oil industry are giving thought to plans for the present year. The outstanding characteristic of the industry in 1928 was the successful curtailment of oil production to the market's needs. It has been thought advisable to look ahead and endeavor to anticipate the oil demand for the coming year, and thus determine the volume of oil that can be safely produced without causing major additions to surface stocks. The year has been one of smaller additions to stocks than in 1927, a record demand for oil products, and a further developed spirit of cooperation among oil producers, as well as various other achievements. It is well to pause and take stock of ourselves. Present Status of Crude Oil Supply and Demand The total daily new supply of oil is at this time1 about 2,960,000 bbl. per day, made up of 2,585,000 bbl. domestic crude production, 125,000 bbl. casinghead gasoline, and 250,000 bbl. of imports. With the present low consumption, due to the falling off in the winter season demand, it is estimated that about 150,000 bbl. a day are now being run to storage, and that the first three months in 1929 will see large-sized additions to storage. Consumption plus exports of oil have increased at a regular rate from year to year, and although oil production in 1928 passed the 1,000,000,-000 bbl. mark for the second time in the history of the United States, with a production of 25,000,000 bbl. more than in 1927, only 30,000,000 bbl. were added to storage during 1928. This is compared to an addition of 65,500,000 bbl. in 1927.

Jan 1, 1929

By C. P. Parsons

Caliper logging is a practice of measuring the variations in the diameter of the open hole in a well. This information is useful for many purposes, among which are: Determining the volumetric capacity of the portion of open hole to be cemented; the amount of gravel to be used for gravel-packing a well; the size and location of seat for a packer to be placed in a well; studying the effects of nitroglycerin shots; studying the effects of acidizing; studying the cause of drill-pipe failures; studying drilling technique; geological correlations. This is a new practice in oil fields and is eliminating considerable guesswork. Introduction Caliper logging of the open hole in oil wells, recently introduced and now showing initial results in many sections of the country, is providing information that is filling a long-felt need in oil-well cementing and in numerous other oil-field practices. Briefly, it measures the variations in diameter, of the open hole in a well. This direct physical measurement of the strati-graphic profile has considerable value for subsurface interpretations by the geologist, engineer, driller and others charged with the responsibility of properly completing and repairing oil and gas wells. The caliper shown in Fig. I is run into a well in closed position. The four arms are released when logging is to start. These arms are independent of each other. As the calipers are pulled upward through the open hole, the arms are like nimble fingers feeling the changing profile of the hole. This mechanical action is in turn converted into an electrical circuit, which is connected to a recording mechanism at the surface. a. Lowered into well in closed position. b. Arms released. Readings are made while caliper travels upward. Direct recording is made at surface, in inches. The recording of the diameter of the hole is directly in inches.

Jan 1, 1943

By C. P. Parsons

Caliper logging is a practice of measuring the variations in the diameter of the open hole in a well. This information is useful for many purposes, among which are: Determining the volumetric capacity of the portion of open hole to be cemented; the amount of gravel to be used for gravel-packing a well; the size and location of seat for a packer to be placed in a well; studying the effects of nitroglycerin shots; studying the effects of acidizing; studying the cause of drill-pipe failures; studying drilling technique; geological correlations. This is a new practice in oil fields and is eliminating considerable guesswork. Introduction Caliper logging of the open hole in oil wells, recently introduced and now showing initial results in many sections of the country, is providing information that is filling a long-felt need in oil-well cementing and in numerous other oil-field practices. Briefly, it measures the variations in diameter, of the open hole in a well. This direct physical measurement of the strati-graphic profile has considerable value for subsurface interpretations by the geologist, engineer, driller and others charged with the responsibility of properly completing and repairing oil and gas wells. The caliper shown in Fig. I is run into a well in closed position. The four arms are released when logging is to start. These arms are independent of each other. As the calipers are pulled upward through the open hole, the arms are like nimble fingers feeling the changing profile of the hole. This mechanical action is in turn converted into an electrical circuit, which is connected to a recording mechanism at the surface. a. Lowered into well in closed position. b. Arms released. Readings are made while caliper travels upward. Direct recording is made at surface, in inches. The recording of the diameter of the hole is directly in inches.

Jan 1, 1943