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By George H. Ashley

The Legislature of the Commonwealth of Pennsylvania at its last session passed a new act dealing with barrier pillars, which may have a wide interest in other states. In the past the laws of Pennsylvania have required that the superintendent of a mine "shall not permit the mining of coal within 50 ft. of any abandoned mine containing a dangerous accumulation of water, until said danger has been removed by driving a passageway to tap and drain off said water, as provided for in this act: Provided, That the thickness of the barrier pillars shall be greater aid shall be in proportion of one foot of pillar thickness to each one and one-quarter feet of water head, if in the judgment of the engineer of the property and that of the district inspector it is necessary for the safety of the persons working in the mine." Thus it has happened that a thickness of several hundred feet has necessarily been left in pillars in mining. It has seemed to many in the mining industry that this left an unnecessary amount of coal in pillars, and did not provide that the pillar be left equally on the two sides of the mine. As a result the General Assembly of 1927 by Joint Resolution authorized the Governor to appoint a Commission of "seven prominent citizens, of whom four shall be recognized mining engineers, one shall be a hydraulic engineer, one a geologist of recognized standing in his profession, and one a State mine inspector from the bituminous coal mining district, to investigate and report upon barrier pillars in the bituminous coal region." The Governor appointed the following Commission: Morris Coulter, Clearfield Bituminous Coal Corp., Indiana, Pa.; A. E. Roberts, Monroe Coal Mining Co., Revloc, Pa.; George T. Lewis, Westmoreland Coal Co., Irwin, Pa.; Morris Knowles, hydraulic engineer, Pittsburgh, Pa.; Thomas A. Mather, State Inspector of Mines, Tyrone, Pa.; A. B. Jessup, Anthracite Coal Operators Association, Jeddo, Pa.; George H. Ashley, State Geologist, Harrisburg, Pa. Mr. Coulter was elected Chairman and Mr. Ashley, Secretary. This Commission held meetings in Harrisburg, Johnstown and Pittsburgh. It obtained and considered the laws and experiences of other states and European countries. Some of its members conferred at length with the directors and other members of the U. S. Bureau

Jan 1, 1930

By George Young

DURING the spring of 1910 I visited a number of open-pit brown-coal mines and underground workings in the vicinity of Halle, Halberstadt, Leipsic, Cologne and Bonn. The notes which I took and the observations which I made at the time have been condensed and make up the principal part of this paper. Certain supplementary information has been taken from several sources which are given in the paper. The mining of brown coal is one of the important industries of Germany. The coal varies in color from dark brown to almost black and is soft like loam. Pieces of wood and strips of bark and, even parts of tree trunks are frequently encountered in the excavation although the coal for the most part consists of a pulverulent, more or less matted mass of small particles of vegetal matter. It is a product between peat and lignitic coal. An analysis, taken from Coal Resources of the World shows the approximate composition of the material: Moisture, 53.73 per cent.; ash, 4.98; fixed carbon, 18.08; volatile carbon, 23.31 per cent. The principal characteristic is the amount of moisture. This seldom runs less than 48 per cent. The ash is usually low and ranges from 5 to 10 per cent. The sulphur content is usually less than 0.5 per cent. The heating effect of the fuel ranges from 2,000 to 2,500 calories.

Jan 2, 1916

By Ian Campbell

THE year 1952 was marked by several new alltime highs in industrial mineral production; by an easing of the critical situation with respect such minerals as fluorspar and sulphur; by important production of asbestos, lithium, and rare earths; by the perfecting of new products which will place new demands upon industrial mineral supplies, such as "Fiberfrax", and the finding of new uses for old minerals, such as wollastonite; by continuation of basic and applied research; and publication of a notable study of the national mineral economy, viz., the "Paley Report".

Jan 2, 1953

By S. Gilbert, G. R. Bailey

A further evaluation of the bomb-sampling method for determining the oxygen content of liquid steel is presented. The results of this study and their close agreement with the results of an earlier evaluation confirm the conclusion that the bomb-sampling method is valid for obtaining representative samples for the determination of the oxygen content of a liquid steel bath. WHAT constitutes the most desirable procedure for obtaining a sample suitable for determining the oxygen content of a liquid steel bath has been a controversial subject for several years. In 1952 Huff, Bailey, and Richards' described a modification of the bomb-sampling technique originated by McCutcheon and Rautio.' In both the modified and original techniques, a small cast-iron or steel mold containing aluminum wire and appropriately covered is inserted into the furnace, coated with slag, and then plunged into the metal bath. Upon entering the metal, the cover melts and a sample of the steel bath enters the mold. The data presented by Huff, Bailey, and Richards' indicated that reproducible samples could be obtained by their method. Furthermore, the oxygen analyses from samples obtained by their method agreed better with those from controlled laboratory experiments than did analyses from samples obtained by methods previously suggested for sampling large liquid-metal baths. Most techniques, other than bomb-sampling, require that a sample of liquid steel be removed from the furnace in a well slagged spoon and poured into an iron mold containing aluminum or into a massive copper mold for rapid chilling. Pouring in this manner requires that the sample pass through the air. The controversy, then, is somewhat as follows: Proponents of the spoon-sampling method and similar dip-and-pour methods feel that the introduction of a cold steel mold into a molten steel bath may result in a localized boiling condition that may deplete the steel of oxygen to a significant degree in the area where the bomb is introduced. Conceivably this boil could cause results that are, on the average, too low and nonrepresentative of the bath composition. On the other hand, samples that are spooned and then poured through the air may also be nonrepresentative because of oxidation by the atmosphere. The restrictions imposed in sampling with a spoon are much more stringent than those imposed when sampling with the bomb-type mold within the furnace. The spoon sample must be taken in a well slagged spoon, a requirement that depends on the condition of the slag in the furnace. Also, the samples must be poured as quickly as possible, without shaking the spoon and without allowing slag to enter the mold. The necessity of fulfill-

Jan 1, 1955

By Bruno V. E. Nordberg

Hoisting is one of the earliest endeavors of man with machinery, for hoisting was probably used by the early Egyptians. Treadmills were used for general hoisting until early in the nineteenth century and it was a short step only to attach a Watt steam engine to the rope drum of a hoist. One of the earliest steam hoists was built for a coal mine at Frisne, near Valenciennes, France. It was a remarkable piece of engineering created by James Watt in 1811, using a wooden drum on a vertical shaft. This followed the crude hoist by Holtzhausen in 1803, which used a drum of wood on a horizontal shaft.' In this country there were examples of crude mine hoists, which have been developed into the efficient machines in use today. African and Australian mines show examples of both extremes, and have an array of fine hoisting equipment exemplified in those built by British manufacturers. The influence of both English and American engineering in hoisting is interestingly evident in Canada. The information available to the writer does not reveal this to be true of South Africa, although American-built hoists have been furnished. Mining camps develop their own style of equipment, adapted to local conditions. For instance, the Butte mining district adheres to the straight drum with friction clutches, because of the great number of levels from which hoisting is done or to which men and material are lowered and the necessity for hoisting or lowering unbalanced. The north Michigan copper country uses both straight and cylindroconical drums and hoists continually in balance, so that the drums are not clutched to the main driving shaft. The Joplin mining district, Missouri, has its own peculiar small hoists. Other individual mines or localities in which a number of mines have been developed show individualistic types of hoists, depending upon their particular problems. In each instance, however, the particular problem must be carefully analyzed, as conditions are seldom so near the same that a number of identical hoists can be used to advantage.

Jan 1, 1940

By J. D. Rice, S. C. Pitzer, C. E. Thomas

Interpretation of pressure build-up data obtained in the conventional manner has often been difficult because of the deviation from theoretical behavior. Major causes of this deviation have been attributed to damage and afterflow, and to fluid redistribution in the wellbore which, in extreme cases, can result in a pressure hump in the early portion of the build-up curve. Theoretical investigations show that bottom-hole pressure is definitely influenced by phase redistribution in the tubing column during surface shut-in tests, and that the magnitude of the effect is sensitive to the producing gas-oil ratio and stabilized rate of flow in the well. For field experiments a wire-line tubing packer, which can be run in the tubing against a stabilized flow rate, was developed for bottom-hole shut-in tests. By use of this bottom-hole .shut-in method, pressure humps previously observed in surface shut-in tests were completely eliminated and the effects of afterflow minimized. Analog and digital computer studies have been made to obtain theoretical curves for comparison with field curves, and remarkable agreement between the results of bottom-hole shut-in tests and theoretical curves has been obtained. INTRODUCTION Pressure build-up data from shut-in wells have been used by the petroleum industry to determine the permeability of the formation, to estimate wellbore damage, to evaluate the static reservoir pressure and to speculate reservoir volume. Calculation of these factors is based on methods of analysis developed for theoretical systems whose build-up curves have a charac- teristic shape when the wells are shut-in at the sand faCe.1,2,3,5,8,10 However, field curves obtained by conventional surface shut-in methods do not always exhibit this characteristic. Such factors as stratification, rock heterogeneities and irregular reservoir geometry can cause the character of a build-up curve to deviate from that predicted by theory for a simple system. In addition, all field build-up data are affected by the methods utilized in obtaining the measurements. Conventional surface shut-in techniques allow two effects to occur which contribute directly to the manner in which pressure builds up at the sand face. The first, afterflow, has been recognized for some time and methods are available for estimating the magnitude of its effect and for correcting its influence.' The second, phase segregation in the tubing column after shut-in, has been reported only recently and appears to exert a considerable influence on the character of field build-up curves.!' In extreme cases, phase segregation can produce "pressure humps" in the early portion of the build-up curve. Such curves have been considered anomalous and have defied analysis. It is the purpose of this paper to discuss the effect of phase segregation in the tubing string during build-up and to present a bottom-hole shut-in technique for obtaining field build-up data which minimizes the influence of afterflow and eliminates phase segregation effects. It will be shown that reliable reservoir information can be calculated from build-up measurements obtained using this method, even though conventional surface shut-in tests on the same wells yield anomalous data. DISCUSSION OF PHASE REDISTRIBUTION EFFECTS Some of the effects of phase redistribution on pressure build-up curves have been described previously by Matthews and Stegemeier" who have presented evidence that phase segregation is responsible for the pres-

By M. D. Cooper

FOr the purpose of obtaining some first-hand data in regard to the shooting clown of coal in bituminous 'nines, it was the writer's good fortune to be employed as a shot-firer for almost one year. In all, 6,020 shots were fired by him during this period. All of the work was clone in what is known as the South Main section of the No. 2 Mine of the Ellsworth Collieries Co., Ellsworth, Pa., a subsidiary of the Lackawanna Steel Co. Position of Shot-firing in the Cycle of Operations The established practice of the Ellsworth Collieries Co. calls first for the undercutting of the coal by electric chain machines across the face of the entry or room. This is followed by replacing any posts removed by the machine-runners, or the setting of new posts or timber, as may be required. After this has been done the machine cuttings are loaded into cars. Then the coal is spragged, and a shot hole drilled to the depth of the undercut. Next in order, the shot-firer loads the hole and fires the charge. The working place is then cleaned up, timbered if necessary, the sides and face squared up, and loose material taken down. The face is again ready to be undercut.

Jan 1, 1917

Organization Place Date 1919 American Society of Civil Engineers..: Twin Cities, Minn. June 17-20 American Society of Mechanical Engineers Detroit, Mich. June 17-20 American Institute of Chemical Engineers Boston, Mass. June 18-21 American Drop. Forge Association Pittsburgh, Pa June 19-21 American Institute of Electrical Engineers Lake Placid, N. Y. June 24-27 American Society for Testing Materials Atlantic City, N. J. June 24-27 Society for Prom. of Engng. Education Baltimore, Md. June 25-28 American Chemical Society Philadelpia, Pa. Sept. 2-6 National Assn. of Stationary Engineers Huntington, W. Va. Sept. 8 American Peat Society.. Minneapolis, Minn. Sept. 22-24 American Iron; Steel Electrical Engineers St. Louis, Mo. Sept. 22-26 American Institute of Min. and Met. Engineers, Chicago, Ill. Sept. 22-27

Jan 6, 1919

Jan 1, 1928

By R. V. Higgins

This paper presents a computer method to obtain the shape factors and equal cell volumes of the channels for any well spacing pattern from a potentiometric model. By using this program the authors have processed the data for the seven-spot, direct line-drive and the staggered line-drive patterns. The data for the five-spot pattern had been previously processed by a noncomputer method and are included for completeness. The shape factors and volumes for the channels are presented in tables for those who want to use them to process data using their own permeability relationships and viscosities of their reservoir oils. The authors have used the data and sets of representative permeability curves to process sample calculationr of waterflood performances. The comparison of the calculated results shows that the influence of well spacing is small. The permeabilities of the reservoir rock to oil and water had a greater influence on oil recovery for a given pore-volume throughput of water than the well spacing pattern. The more water-wet the reservoir rock, the better the possibility of permeabilities which are conducive to good recovery. The viscosity of the reservoir oil also influences the recovery more than the well spacing pattern. The reduction in the percentage recovery of oil with increase in viscosity of the reservoir oils is small when oil viscosities are in the range of 0.1 to 3. Above this range the reductions in recoveries are extensive. Sample comparisons of the time required for different patterns to recover the oil are presented. Results of an example calculation are given to show the effect of the permeability profile on recovery. INTRODUCTION The effect of well spacing pattern on the recovery of oil when flooding with either gas or water has been studied by many investigators. Muskat et al.1 presented an analysis using conductivity, sweep efficiency and unit mobility to the time of breakthrough. Dyes et al.2 used experimental techniques (X-ray shadowgraphs) and different mobility ratios. They presented quantitatively the relationship between mobility and sweep efficiency at and after breakthrough. Hauber3 presented a method to predict waterflood performance for arbitrary well spacing patterns and mobility ratios. Craig et al.,4 using techniques similar to Dyes et al. to determine sweep efficiency for a five-spot pattern, added the use of relative permeability curves at breakthrough and thereafter. Douglas et al.5 sed rela- tive permeabilities and continuously changing saturations throughout the entire five-spot flood pattern. In obtaining their solutions they used finite-difierence equations. Hig-gins and Leighton6,7 also used relative permeabilities and continuously changing saturations throughout the pattern before and after breakthrough. They employed techniques that process a flood-pattern calculation on the computer in about one minute. The methods of Douglas et al. and Higgins and Leighton both checked closely the laboratory results for a wide range of mobility ratios. This paper presents some sample performances calculated by the Higgins and Leighton method that show the effect on recovery of different permeabilities and viscosities using the seven-spot, the line-drive and the staggered line-drive, as well as the fivespot flood pattern. No previous paper has presented these data using different permeability curves and continuously changing saturations throughout the flood patterns. The paper also presents (1) the results and analyses of the flood-pattern prediction, (2) the computer techniques for determining the shape factors and volumes from the potentiometric models for the foregoing flood patterns, and (3) the shape factors and volumes of the channels of the flood pattern in the event reservoir engineers may like to process waterflood calculations using their own permeability curves and reservoir oils. DESCRIPTION OF METHOD VOLUMES AND SHAPE FACTORS The use of channels taken from a potentiometric model (see Fig. 1) to aid in calculating the performances of water floods of nonlinear patterns has been thoroughly explained in the literature.0,7 Therefore, very little theory, discussion, or proof regarding this phase will be repeated in this paper. The computer method presented in this paper to calculate the volumes and the shape factors of the channels of potentiometric models employs the trapezoidal rule for the volumes and the Pythagorean theorem (the hypotenuse equals the square root of the sum of the squares of the two sides of a right triangle) for the shape factors. In calculating the volume of a channel, the area of each cell in the channel is determined and then multiplied by the thickness to obtain the volume. In determining the areas of the cells, trapezoids are constructed whose vertical sides are spaced Ax apart, as shown in Fig. 2. The length of the sides is the difference between an ordinate cut off by the top and bottom of the cell — usually equipo-tentials. The coordinates of the points along an equipo-tential or streamline are obtained by Lagrange's8 equation of interpolation for which the constants are coordinate points at the intersections. Three intersections for con-

Jan 1, 1965

Jan 1, 1925

By Alden B. Greninger

THE study of mosaic structure of crystals1 has been confined until recently to the field of theoretical physics Crystallographers, in general, have neglected the subject, although X-ray crystallographers constantly make use of formulas for intensities of X-ray reflection as modified by mosaic structure Work on mosaic structure has centered chiefly on the task of proving or disproving the secondary-structure theory of Zwicky,2 and very little attention has been paid to the visible imperfections of crystals A Goetz has been responsible for most of the supposed experimental confirmations of Zwicky's theory 3 On the other hand, Smekal,4 and Orowan,5 among others, maintain that these is neither theoretical nor experimental evidence to substantiate Zwicky's secondary structure

Jan 1, 1935

"The Butte, Anaconda & Pacific railway extends from Butte to Anaconda. The electrification comprises 30 miles of main line single track, and includes sidings, yard and smelter tracks. When complete the electrified trackage will total about 90 miles on a single track basis.The traffic conditions are unusually severe as they consist principally of hauling copper ore from the Butte mines to the smelters at Anaconda, as well as hauling all the mine supplies, lumber, etc., in both directions; this traffic amounts to approximately 5,000,000 tons of freight per year. The maximum grade against the load is .3 per cent and the maximum train consists of 50 loaded steel ore cars, weighing 3,400 tons. .The locomotive units, two of which will be used for freight trains, weigh approximately 80 tons each. In addition to the freight business, there will be a certain amount of passenger traffic.The power for operating the Butte, Anaconda & Pacific railway is generated by, the Great Falls Power company, and is transmitted to the sub-stations at 100,000 volts. The synchronous motors are supplied with power at a potential of 2,300 volts, 60 cycles, 3-phase. Voltage regulators are installed in each sub¬station to secure the benefit of synchronous condenser effect of the motors.The passenger and freight locomotives are exactly similar, with the exception of the gearing.The roller pantograph mounted on the top of the cab is operated by air from the engineers position.The adoption of the 2,400-volt apparatus for so important a system, where the conditions of operation are so severe, is interesting of itself, as indicating the trend that future electrifications of importance may follow. A trolley potential of 2,400 volts was only adopted after a thorough investigation of other systems already in operation."

Jan 1, 1913

Establishment of a Bureau of Mineral Research at the Michigan College of Mining and Technology, initiated by the State of Michigan with legislation in 1951, is moving toward realization. The Michigan Legislature appropriated $24,000 to cover preliminary costs of plans and specifications for "engaging in a broad, widespread study of the beneficiation of lowgrade ores, of ore dressing, and all the problems of metallurgy that enter into such a program." Ralph C. Calder, of Detroit, who designed Michigan Tech's campus buildings, is preparing plans for the proposed Ores Research Building. Members of the college staff, Professors F. J. Tolonen, W. E. Keck, and Research Engineer Paul Jasberg are assisting in preliminary planning. C. Harry Benedict, retired chief metallurgist of Calumet and Hecla and a member of Michigan Tech's Board of Control, is assisting with technical details. Professor Nicholas Manderfield, head of the department of Mineral Dressing, was assigned to visit other research installations and suggest plans for the Bureau.

Jan 1, 1952

By E. C. Kersey, R. J. Gennone

MetALLOGRAPHIC investigations of composites of zinc alloys and aluminum have been made to study the effects of various thermal treatments on the zinc-alloy grain size and diffusion of zinc into the core material. The use of various alloys of zinc has necessitated the development of a universal etchant which will allow microscopic examination of the zinc grain size regardless of the composition.

Jan 1, 1960

By C. M. Nickerson

The possibility of deeper production in the Buena Vista Hills was first considered in 1933. At that time, however, the heavy state curtailment program served to deter any operator from drilling test wells, which, if successful, might upset the proration schedules. Because most of the acreage was held by several major operators and the remainder by substantial independents, the adoption of a plan of cooperative development was considered desirable. Such a plan was formulated for the development of any deeper oil and gas horizons that may be found to exist. This plan, which was signed by the Secretaries of the Navy and of the Interior on behalf of the United States on July 9,1936, is now effective for the development of lands within the area shown on Fig. 1. Unlike most unit plans, the present cooperative development plan permits each operator to drill and produce his own wells. For the purpose of this plan the Buena Vista Hills field is divided into two pools. The present production is classed as the " old pool,"' while any future production below a certain marker which roughly coincides with the bottom of the Santa Margarita formation is included in the "pool" to which the provisions particularly apply. Naval Petroleum Reserve No. 2 lies within the area and constitutes the major portion of the Federal leases subject to the plan. There are 39,040 acres and 27 operators within the area. Twenty-six operators controlling 99.5 per cent of the acreage have signed the agreement. Geology oF the Buena Vista Hills The Buena Vista Hills consist of a low range in the southern portion of the San Joaquin Valley, and are roughly parallel to the adjacent Temblor range to the south. The Elk Hills oil field parallels the Buena Vista Hills a few miles to the north. The subsurface structure is a re-entrant anticline upon the major Midway-Sunset monocline. This anticline is divided into two minor

Jan 1, 1937

By Jorge Munoz Reyes, Guillermo

The new entity, Yacimientos Petroliferos Fiscales Bolivianos, created in 1936 for the development and exploitation of all petroliferous zones of Bolivia, including those formerly belonging to the Standard Oil Co., is doing its utmost to bring about rapid development and by this means to create a new source of revenue for the State. With this in view, Y.P.F.B. has opened a new field in the Samaipata region, on the main road between Cochabamba and Santa Cruz. Installation of machinery has begun for the drilling of several wells on the five anticlines that occur in this region. Work has also begun in the Saipuru field, on the Santa Cruz-Charagua highway, which was discovered by the Standard Oil and temporarily abandoned. In this new field, a topping plant will be installed, to supply gasoline and kerosene to Santa Cruz. Explorations are also being made on the neighboring structures of Saipuru. At the end of 1937, the committee that is to study the region of the Chapare in the northeastern part of Cochabamba, was organized. The structures were studied 10 years ago by Kirtley Mather and other geologists. It is hoped that by March 1938 this camp will begin work, as this zone gives promise of being valuable. Development The capacity of the refinery at Camiri has been enlarged in order that it may supply all the needs of that region. In order that the supply of crude may be adequate, several wells that had been almost abandoned by the Standard Oil are being cleaned out. New wells have been located at this camp following the principal anticlinal structure, and during the first half of the year 1938 several wells will be drilled. The same program is being followed in Sanandita but on a greater scale, as the nearness of this district to the Argentine border, which is the best market for the Bolivian petroleum of the south, allows immediate sale of the petroleum. Possibly a new refinery will be installed at this camp, as the one now in existence is only a rudimentary distillery. At the Bermejo camp, which is farther south, intensive work is being done to bring the wells into production. The Standard Oil produced limited quantities several years ago, but since 1927 the wells of this dis-

Jan 1, 1938

By J. H. Frye, S. G. Holder, E. E. Stansbury

Internal friction studies on annealed and cold-worked pure silver and alloys of silver with 4.5 atomic pct each of Cd, Sn, and Sb are reported. Small amounts of cold work, introduced by stretching pure silver, decrease the internal friction; large amounts of cold work, by wire drawing, cause this decreased internal friction to rise. Results of severol anneoling histories on the room-temperature in-ternal friction indicate a rather complex recovery and recrystallization behavior. A rather system-atic alloy effect is observed for the elements of Period V-B in silver in both the annealed and cold-worked states. DURING recent years internal friction measurements at very small stress levels have been interpreted in terms of structural models and mechanisms occurring within the metal or alloy.These measurements have been made over wide ranges of frequency of vibration and of temperature. While the effects of impurities, alloying, and plastic deformation have been studied by numerous investigators, no investigations of the effect of a series of solutes related by their position in the Periodic Table on a given solvent seem to have been reported. The present paper reports internal friction measurements on silver and on certain silver-base solid solutions to determine the values of room-temperature internal friction associated with varying amounts of plastic deformation and after different annealing

Jan 1, 1957

By K. J. Richards, W. J. Schlitt

A combination of industrial and laboratory data is used to explain the interrelationships between operating parameters and cementation plant performance as measured by copper recovery and iron consumption. The chemical factors considered are the relative concentrations of copper and ferric ions in solution, acid concentration, the possible buffering action of other dissolved salts and solution temperature. The effects of flow conditions, solution oxidation, the presence of metallic copper and retention time are also considered. Based on the various relationships developed, possibilities for plant optimization are discussed.

Jan 1, 1974