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By Barry H. G. Brady

A state of stable equilibrium is required in a mine structure to ensure that small increases in the mined void are accompanied by only small displacements of the rock mass. Methods of determining the stability of equilibrium in a rock mass currently require a geometrically regular stoping layout, and introduce a number of simplifying assumptions. The method reported in this paper models the mine near-field using Finite Elements, and the far-field using Boundary Elements. The stability of equilibrium in the modelled structure can be assessed directly from the value of selected principal minors of the global stiffness matrix.

Jan 1, 1981

By Zay Jeffries

IT is well known that many properties of a given metal vary with the size of grain or cell. For most industrial purposes, where high ultimate strength and high elastic limit are desired, the manufacturer tries to produce a. fine-grained structure. For some purposes, for example in transformer iron, a coarse-grained structure is desirable. The terms fine-grained and coarse-grained are used only in a relative sense. For example, a fine-grained cast copper might have grains 100 times larger than coarse-grained high-speed steel. Similarly, a fine-grained steel rail might have grains or cells 100 times larger than coarse-grained wire, which was made of steel from the same heat. In some metals, the change in grain size is more appreciable than the changes in any of the properties determined by the tensile test. Furthermore, in metals which have been annealed or subjected to high temperatures, grain size may prove to be a better indication of the life of the metal in use than the tensile test. One of the authors was able to supplant the tensile test with grain-size determinations in the control of. metal for a specific use, the latter determination being more indicative of. the life of the metal part than the tensile test. A grain-size determination with a tensile test is, of course, more valuable than either singly. At present there is a decided dearth of data on actual grain-size determinations in metals, and consequently a corresponding lack of ability to interpret the determinations after they are made. It would be desirable to have correlation made between grain size and properties of metals, comparing thousands of determinations. In this way, grain-size determinations might be interpreted in much the same manner that tensile tests are now.

Jan 12, 1915

By Leonard Larson

DURING several years immediately preceding the adoption of wet-charge smelting at McGill, various necessary conditions affecting this procedure, such as plant rearrangement and the metallurgical nature of the concentrate produced at the concentrator, were fully considered. Wet-charge smelting is not altogether novel to the recently reconstructed smelter at McGill. A number of years prior to this improvement, when flotation methods were initiated at the concentrator, large tonnages of wet and (at that time) sticky flotation concentrate were charged directly into the reverberatory furnaces, because of the difficulty in handling the entire tonnage in the roasters. The plant had excess reverberatory units and this surplus furnace capacity was utilized to smelt raw flotation concentrate. During the years 1927 and 1928, a number of actual operating furnace test runs were made to determine in principle the feasibility of wet-smelting operation. Results were encouraging, and in November 1932 the roasting plant was shut down. For some time thereafter the wet feed was delivered directly to the reverberatory side-charging calcine hoppers already in place. Feeding the wet material through the old calcine hoppers and charge holes into the furnace involved considerable labor, but under the conditions existing at that time it was desirable to continue wet smelting even under the handicap of this laborious procedure. The smelting plant during this period was on a curtailed production basis, operating only about 15 days per month. The alternate starting up and shutting down of the roasting plant presented a difficult problem and charging the wet material directly to the furnace entirely eliminated this difficulty. The roasting plant was never operated thereafter. EARLY PROCEDURE Fig. 1 shows the general layout of the smelting plant before the smelter was remodeled. Under this arrangement, all concentrates and fluxes except converter flux were delivered in cars to wooden storage bins, which paralleled the roaster building. The material to be roasted was dis-

Jan 1, 1938

By M. H. Waxman, M. Gondouin, H. J. Hill

Streaming-potential experiments were conducted within the Muddy- and Dakota-sandstone interval of a Denver basin well. Analysis of the data shows that, for this case, streaming potentials opposite sands were higher than those opposite shales when the mud was fresh. Streaming potentials opposite shales, however, were of sufficient magniiIlde to be important in SP interpretation. They were linearly dependent upon pressure differential, and they increased with mud filtrate resistivity. The magnitude of streaming potentials opposite sands was influenced by the characteristics of the original mud cake formed at the time of drilling. Use of mud samples taken at the time of logging may not always be satisfactory for determining streaming-potential corrections. Both the streaming and electrochemical potentials were found to be affected by the previous history of the borehole system. Following a change in mud characteristics, several days were required for SP stabilization. This was, in part, due to the mud cake acting as an imperfect shale membrane. INTRODUCTION Laboratory investigations by Wyllie,1 Salisch,2 Moore," Sen Gupta and Bannerjee,0 and Hill and Anderson' have shown that streaming potentials developed across mud cakes deposited on permeable filter beds are of sufficient magnitude to be critically important in SP interpretation. Streaming potentials across shales have been reported by Schenck,' Gondouin and Scala; and Hill and Anderson." The magnitude of the shale streaming potentials obtained by Schenck and by Gondouin et a1 led these authors to conclude that in many cases the shale streaming potential would approximately equal the mud-cake streaming potential. Hill and Anderson, however, obtained somewhat lower magnitudes of shale streaming potential. The field experiment described in the present paper was a cooperative project carried out by the respective operations and research departments of Schlumberger Well Surveying Corp., Shell Development Co. and Shell Oil Co. The primary objective of the experiment was to determine in the borehole the streaming-potential behavior of both shales and mud cakes under conditions approaching, as nearly as possible, those normally encountered in logging practice. METHODS AND EQUIPMENT WELL A Muddy- and Dakota-sandstone vie11 in the Denver basin was chosen for the experiment. Both sandstones were water-bearing and, since reservoir pressures in these sandstones are abnormally low (gradient of approximately 0.25 psi/ft), it was expected that studies of streaming potential could be conducted from low-pressure differentials (approximately 200 psi) to about 27000 psi by bailing mud from the hole, filling up and then applying wellhead pressure. The selected well encountered the Muddy sand-

By H. W. Mead, C. E. Birchenall

SELF-DIFFUSION of cobalt has been investigated by Ruder and Birchenall,1, 2 Nix and Jaumot,3 and Gruzin.4 The results for a given tem- perature differ by a factor of about six in the extreme cases with no really close agreement between any two sets of data. The first two groups of investigators employed the decrease of surface activity method. Since Ruder and Birchenall have shown that the values obtained from this method are sensitive to the surface preparation, it seemed desirable to perform a few check experiments by a method not open to this objection.

Jan 1, 1956

By R. A. Wood, R. I. Jaffee, H. R. Ogden, D. N. Williams

Dispersion-containing titanium-copper alloys were prepared having mean free paths varying from 1.0 to 9.7 P. Tensile studies at room temperature and at 1000°F showed that little or no strengthening occurred when the mean free path exceeded 3 p. However, at lower values of mean free path appreczable strengthening was observed. A considerable amount of strengthening also resulted from copper in solid solution. DURING the past several years, an increasing amount of study has been devoted to dispersion hardening, an alloying process in which increased strength is obtained through the addition of a ran-

Jan 1, 1961

By B. M. Harra, R. L. Hallows, O&apos

The term "modern automatic baghouses" as used in the title of this paper is intended to designate a general type of mechanical fume filter, introduced some 20 years ago and gradually improved since that time. It is characterized by its small filtering bags, enclosed in groups of 15 to 30 in steel compartments, and by its frequency of shaking, as compared to the old type of baghouse, which uses much larger bags, shaken at much longer intervals. Automatic baghouses are produced by a number of well-known manufacturers. Some recently constructed baghouses of the old type have embodied some of the principles of the automatic type, in that they are divided into several compartments, with separate fans for the different compartments, and flue headers arranged so that when the fan to any one compartment is shut down preparatory to shaking the bags in that compartment, the bags are put under suction by the draft from the other fans, thus making possible more efficient cleaning of the bags. These baghouses have motor-driven shaking mechanisms, and generally are operated under higher pressure and shaken at more frequent intervals than was the practice with the old style baghouse, and consequently have greater filtering capacity per unit of bag area. It is possible to interconnect the fan motors and the motors driving the bag-shaking mechanism, with suitable relays and timing devices, so that the operation of this type of baghouse also becomes to a considerable extent automatic. These baghouses are intermediate between the old style of baghouses, strictly speaking, and the completely automatic baghouses. They may he considered just as modern as the latter, and their proponents can no doubt cite many advantages for them. The authors are less familiar with them than with other types, and the following discussion will be limited to a comparison of the automatic baghouses and old style baghouses, with particular reference to the experience of The Eagle-Picher Lead Co. and The Eagle-Picher Mining and Smelting Company.

Jan 1, 1937

Jan 1, 1932

By Kendall E. Born

Production of crude oil in Tennessee during 1936 approximated 20,000 bbl., about the same as in 1935. Accurate figures are available only for the Glenmary field in southwestern Scott County and the Boone Camp, Seabolt, and Coon Hollow pools in north central Morgan County. Small amounts of oil were produced in the Poplar Cove region of eastern Fentress County, in Tinsleys Bottom along the line between Clay and Jackson Counties, and in the Lock Branch pool of northern Jackson County. The renewed interest in these three pools, which were abandoned for several years, reflects the effect of rising prices for crude oil in Tennessee. Developments in these fields were begun late in 1936 and therefore have had little cffect on the production for the year. A nurnber of small scattered wells in abandoned fields in Clay County were pumped intermittently during the year, but no production figures are available on this production. The acidizing of a number of wells in Scott and Morgan counties reported last1 year has been responsible for an increase of nearly 4000 bbl. over 1935 in this region. Results have shown, however, that the Glenmary pay (Glenmary and Coon Hollow pools) at about the top of the St. Louis limestone, responds more favorably to acid treatment than does the Boone Camp (Boone Camp and Seabolt pools) horizon in the Fort Payne formation of lower Mississippian age. This difference is probably due to the siliceous and argillaceous content of the Boone Camp pay. The only natural gas marketed off the lease in Tennessee during 1936 was in Morgan County, where approximately 10,000,000 cu. ft. were furnished the towns of Sunbright and Burrville and the immediate vicinity. The gas occurs with the oil in the Boone Camp field and small amounts were put on the line from the near-by Coon Hollow and Seabolt pools. There are 11 gas wells in the area. Development Although the presence of petroleum in Tennessee was noted more than one hundred years ago, this state has never been an important

Jan 1, 1937

By E. Gybbon Spilsbury

THE introduction of underground machinery in mines, and especially the invention of the rock drill, called attention to the necessity for some motive power to drive them. The use of steam generators underground is as a general thing inadmissible, owing to the, difficulties of ventilation and the transportation of fuel, and the great loss of power by condensation in the pipes, when surface generators are used, added to the inconvenience of getting rid of the exhaust steam, has precluded the direct use of steam for this class of machinery. Water as a power has with very few exceptions proved a failure, owing to its weight and incompressibility, and there-fore the attention of mining engineers has very naturally turned to the use of compressed air. This agent not only answers all the requirements for power, but has the double advantage of greatly assisting in thoroughly ventilating remote workings, and in cooling the underground atmosphere. It is therefore clear that the successful introduction of underground machinery is dependent on the economical production of good and efficient air-compressing machinery. Although many improvements have of late years been introduced in this class of machines, the most of them are open to serious objections, the chief of which are the very small duty they perform for the power expended, and their great expense, due to the complexity of their construction. This latter fault is the chief reason why the introduction of rock drills and other underground engines is so limited, as comparatively few mines can afford to expend the required capital for the installation of a complete compressing plant. But with the introduction of a cheap and effective compressor, there is no doubt that power drills will become as generally used in mines as the hand drills are now. The great excess of power required in most machines to compress air over that given out again by the use of the air thus compressed (amounting as it does in most cases to sixty per cent.) is well known to all mining engineers. Of course a portion of this loss is due to the friction of the air through the pipes, and will always occur however effective the machine used maybe, but the chief cause -of the

Jan 1, 1880

By Harlan N. Barton

A commercially available, portable X-ray spectrograph, lightweight and rugged for vehicle or field camp use, was used to determine Ba, Cu, Fe, Mn, Pb, Rb, Sr, and Zn in stream sediment geochemical samples. Investigations showed a relative standard deviation of 1-3%, detection limits of approximately 100 pg/g and significant matrix effects. Coefficients of correlation greater than 0.9 were obtained between portable X-ray and emission and atomic-absorption spectroscopy analyses. A geochemical map of a known mineralized area showed good agreement with maps prepared by other methods of analysis and sample media.

Jan 1, 1983

By A. H. Bell

The results of repressuring (or gas-drive) have been very encouraging to the several companies doing experimental work along these lines in California. The most notable examples are the Shell and the Union Oil companies at Dominguez, the Marland Oil Co. at Seal Beach, and the California Petroleum Corpn. at South Mountain. The results of the Marland test at Seal Beach are interesting in that re pressuring was started while several wells were still flowing; also, on account of the high pressures required to overcome the hydrostatic pressure exerted by high-head edge water. The well first chosen for repressuring is about halfway up the flank of the structure and had been on the beam making about 250 bbl. of fluid daily, cutting about 60 per cent. emulsion. The fluid lcvel was 230 ft. from the surface and the top of the sand was 4393 ft. Tubing was run to 4000 ft. with a packer and the space above the packer was filled with water to balance the high pressures. Gas was started in slowly to allow the fluid to be pushed back into the sand, and required three days at a pressure of 1500 Ib. per sq. in. before starting into formation. The pressure was once built up to 1800 Ib. and the compressor was shut down for a few hours. When again started, the well took gas at 1500 Ib., and after about three weeks the pressure was dropped to 1450 Ib. The present pressures required range between 1400 and 1450 lb. Volumes as high as 1,500,000 cu. ft. per 24 hr. were put into the well. Increases as high as 50 per cent. in production were obtained in wells up-structure with very little increase in wells down-structure. Also, the water cut on one edge well materially decreased. After about 40 days the repressuring was moved to two wells farther down-structure and the well originally repressured was put on production. The result of this was a great increase in the production of wells one location farther down-structure, a rapid increase in one well one location up-structure, and a decrease in production of the wells farthest up-structure. Later the gas started to short-cut to the nearest well down-structure, nullifying to a certain extent the effects of the repressuring work. The increased production that could be definitely attributed to the repressuring work

Jan 1, 1928

Jan 1, 1905

By Ralph V. Higgins

This paper concerns the magnitude of the amount of supersaturation that occurs in an underground reservoir during the flow of oil and gas to wells and to the amount of undersaturation that occurs during repres-suring of an oil reservoir where some effective permeability to gas exists. The study is based on earlier laboratory findings of other investigators on the rate of diffusion of gas in oil as a function of the depth of oil. Utilizing these relationships and the principles of reservoir mechanics, a quantitative estimate of undersaturation and super-saturation was calculated. The results showed that the diffusion of the gas is rapid enough that for all practical purposes no supersaturation exists during the flow of oil to wells or undersaturation during repressuring in reservoir sands having some effective permeability to gas. The reason diffusion of the gas virtually keeps the oil saturated is the long time required in radial flow for oil to reach the well and the slow rate at which pressure in reservoirs is increased during repressuring. INTRODUCTION Knowledge of the phase relationships during flow of gas and oil in an underground reservoir is essential to operating the reservoir in the most efficient manner. In material-balance calculations and in fluid-flow studies, the oil is assumed to contain all the gas that it will dissolve at given temperature and pressure. Pressure-volume-temperature relationships are normally obtained in the laboratory using "bottom-hole" or combined samples of the reservoir fluids. In such laboratory determinations equilibrium is obtained between the oil and gas in the pressure cells by mechanical agitation. During the flow of oil and gas in reservoirs, however, no comparable agitation occurs to mix thoroughly these fluids to aid in effecting equilibrium between the two phases. During repressuring of a partly depleted underground reservoir, the gas is usually injected into the reservoir faster than the oil can absorb it; consequently, the oil is undersaturated. On the other hand, as the oil flows through the reservoir to the wells during producing operations the pressure decreases faster than the gas in solution can diffuse through the oil to the gas phase. The oil therefore is supersaturated with gas. Where the oil is undersaturated, gas diffuses away from the gas-oil interface, and where it is supersaturated the gas diffuses toward the interface. In either case the gas moves from a higher to a lower saturation. This report contains the results of a study of the factors influencing the degree of nonequilibrium of the phase relations of oil and gas in porous mediums during the flow of oil through reservoirs to wells and also during the injection of gas into partially depleted sands. Data from an underground reservoir are presented and the degree of supersaturation during the flow of the oil through the reservoir to the well is approximated. Also data from another reservoir are used and the degree of undersaturation during the repressuring operation is calculated. In addition, the flow rates of oil in laboratory experiments and in underground reservoirs are compared, as data from the laboratory are often used to interpret events in the reservoir, and the rates of flow influence appreciably the degree of nonequilibrium. Much of the contents of this report was prepared in 1943; but, because of other activities during and since the war, the manuscript was left untouched until 1952, when it was decided to include an estimate of the amount of undersaturation during repressuring as well as supersaturation during flow.

Jan 1, 1955

By H. W. Page

Petroleum requirements since V-J day have been appreciably higher than predicted. Foreign operations now exceed maximum wartime levels by about 14 per cent. Domestic operations since V-J day have averaged 92 Per cent of the wartime peak. In spite of maximum foreign refinery runs, large exports of all products, except residual fuel oil, are necessary to meet foreign demand. During the next few years it is expected that foreign operations will continue at capacity, including new installations, but that, because of increases in foreign demand, exports will continue at about their present level. Domestic operations will increase during this period and crude production probably will exceed maximum efficient rates. Even after 10 years some exports probably will be required, but eventually these will be supplanted by increased output of foreign refineries, except for small tributary exports. The increase in domestic requirements will exceed the decline in exports. Unless findings of crude oil exceed present expectations, the increasing demand will be met by increased imports and synthetic methods-—such as the Hydrocarbon Synthesis Process for conversion of natural gas and coal to gasoline and distillates. Catalytic cracking installations will increase as crude availability decreases. This will help to meet the increasing demand for gasoline but will intensify the domestic shortage of residual fuel oil. Eventually larger imports will be required to satisfy the demand for this product. Introduction Under the pressure of the wartime period, there was time only occasionaly to look ahead in anticipation of what the postwar era held for the petroleum industry. Perhaps the general expectation was that a rather pronounced decline in the level of industry petroleum operations would take place shortly after the end of the war, with the impact felt mainly on the economy of the United States- It is of interest now, nine months after V-J day, to take inventory of the near-term situation and see what significant forces are at work. With this as a starting point, it should be possible to engage in something more satisfactory than pure speculation concerning trends in the immediate future and 10 to 20 years ahead. Present and Near-term Situation During the nine-month period following V-J day, foreign crude oil production and rebery operations have actually increased the These activities were at maximum capacity on V-J day but the continuation of drilling programs, the completion of new and rehabilitated refineries and of transportation facilities during the Past nine months have increased the foreign capacity. This added capacity has been fully utilized. Foreign crude oil production in May 1946 is about 14 per cent higher than during July 1945 and refining operations some 12 per cent higher' During the same period there has been a falling off in similar activities within the

Jan 1, 1947

By H. W. Page

Petroleum requirements since V-J day have been appreciably higher than predicted. Foreign operations now exceed maximum wartime levels by about 14 per cent. Domestic operations since V-J day have averaged 92 Per cent of the wartime peak. In spite of maximum foreign refinery runs, large exports of all products, except residual fuel oil, are necessary to meet foreign demand. During the next few years it is expected that foreign operations will continue at capacity, including new installations, but that, because of increases in foreign demand, exports will continue at about their present level. Domestic operations will increase during this period and crude production probably will exceed maximum efficient rates. Even after 10 years some exports probably will be required, but eventually these will be supplanted by increased output of foreign refineries, except for small tributary exports. The increase in domestic requirements will exceed the decline in exports. Unless findings of crude oil exceed present expectations, the increasing demand will be met by increased imports and synthetic methods-—such as the Hydrocarbon Synthesis Process for conversion of natural gas and coal to gasoline and distillates. Catalytic cracking installations will increase as crude availability decreases. This will help to meet the increasing demand for gasoline but will intensify the domestic shortage of residual fuel oil. Eventually larger imports will be required to satisfy the demand for this product. Introduction Under the pressure of the wartime period, there was time only occasionaly to look ahead in anticipation of what the postwar era held for the petroleum industry. Perhaps the general expectation was that a rather pronounced decline in the level of industry petroleum operations would take place shortly after the end of the war, with the impact felt mainly on the economy of the United States- It is of interest now, nine months after V-J day, to take inventory of the near-term situation and see what significant forces are at work. With this as a starting point, it should be possible to engage in something more satisfactory than pure speculation concerning trends in the immediate future and 10 to 20 years ahead. Present and Near-term Situation During the nine-month period following V-J day, foreign crude oil production and rebery operations have actually increased the These activities were at maximum capacity on V-J day but the continuation of drilling programs, the completion of new and rehabilitated refineries and of transportation facilities during the Past nine months have increased the foreign capacity. This added capacity has been fully utilized. Foreign crude oil production in May 1946 is about 14 per cent higher than during July 1945 and refining operations some 12 per cent higher' During the same period there has been a falling off in similar activities within the

Jan 1, 1947

By Robert H. Hafner, Irvin R. Kramer, Stewart L. Toleman

IN his paper on the calculation of hardenability from chemical composition, Grossmann1 discussed the effect of most of the alloying elements used commercially. The purpose of the work reported in this paper was to determine the effect of several other elements on hardenability-arsenic, antimony, beryllium, cobalt, columbium, germanium, tellurium, tin, aluminum, and titanium-and to extend the range of composition of some of the elements studied by , Grossmann-chromium, copper, manganese, molybdenum, nickel and silicon. EXPERIMENTAL METHODS To determine the effect on hardenability, suitable amounts of the alloying elements were added to experimental heats and the hardenability determined by means of end-quenched hardenability specimens. The steels were melted in a high-frequency induction furnace with a basic crucible, using ingot iron as a base for some of the heats and S.A.E. 1015 for others. The alloying additions were made as ferroalloys or as metal, depending on the ' alloying element. Hundred-pound heats were split and poured into square, tapered, cast-iron ingot molds with hot tops. Aluminum was not used as a deoxidizer in most of the heats. The ingots were homogenized for 12 hr. at 1260°C. (2300°F.) , and forged into rounds of 1 ½ in. diameter. These bars were normalized twice from 840°C. (1550°F.) before machining into Jominy bars. The composition of the steels was deter- [ ] mined in most cases by samples taken from the end-quench hardenability specimen. As suggested by crafts,2acid-soluble

Jan 1, 1943

By Thomas E. Howard

Recently, the mining community has begun to move toward a more prominent place in the structure of American society. Extensive press coverage of our energy problems during the past year or two has led to an increasing awareness on the part of the public of the vital role that mining must play if today's standard of living is to be maintained. It appears that mining may be emerging from a status generally characterized in the public mind as an esoteric, dirty, man-killing, land- scape-despoiling endeavor, to a new stature that may eventually become as respectable as agriculture. To be sure, we are still being criticized, as has been the lot of miners since the time of Agricola. In fact, the clamor has never been louder. Nevertheless, the public, in increasing numbers, is beginning to know it needs us. But we cannot be complacent. Our improving stature brings along with it increasing responsibility. The mineral industry will be expected to produce mineral raw materials and fuels in ever larger amounts and sell them at reasonable prices, in the face of rising labor costs, decreasing labor availability, chacging labor attitudes, increasingly stringent environmental regulation, stricter health and safety standards, and a deteriorating geo-political climate.

Jan 6, 1975

By Francois E. Heuze

Today, the favored option for disposal of high-level nuclear wastes is their burial in mined caverns. As an alternative, the concept of deep disposal by rock melting (DRM) also has received some attention. DRM entails the injection of waste, in a cavity or borehole, 2 to 3 kilometers down in the earth crust. Granitic rocks are the prime candidate medium. The high thermal loading initially will melt the rock surrounding the waste. Following resolidification, a rock/waste matrix is formed, which should provide isolation for many years. The complex thermal, mechanical, and hydraulic aspects of DRM can be studied best by means of numerical models. The models must accommo¬date the coupling of the physical processes involved, and the temper¬ature dependency of the granite properties, some of which are subject to abrupt discontinuities, during [a]- ß phase transition and melting. This paper outlines a strategy for such complex modeling.

Jan 1, 1982

By James T. Wood

STRATIGRAPHY structure and closure of the Paloma field are discussed, with some details regarding the present state of development. The Paloma anticline, a large dome modified by faults, is the largest single closed dome in the southern San Joaquin Valley without surface outcrop or topographic expression. It owes its discovery to geophysics. Of nine wells drilled to the Stevens sand, seven are productive. The ultimate productive area may approximate 3000 acres when the limits of the field are determined.

Jan 1, 1942