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By G. Chesneau

Two great discoveries of this century have diminished the dangers of fiery coal-mines,—the sifety-lamp, conceived in 1815 by Sir Humphrey Davy and successively improved by many engineers, such as Clanny, Marsaut, Mueseler, Fumat, etc., and safety-explosives, the appearance of which is comparatively recent, hut which, thanks to the persevering labors of several technical commissions (especially the French commission on explosives), and of the manufacturers and experimental users of these powders, appear likely to play, in the protection of the miner, a part as important as that of the safetylamp itself. Brit while it is true that by the use of a safety-lamp of approved form, and the exclusive employment, with all prescribed precautions, of these new explosives, complete security should be assured, even in highly fiery atmospheres, experience has shown that the imprudence of workmen, or the bad condition of a lamp, may nullify these protective means, so that it ought to be the constant care of the engineers of fiery mines to dilute the fire-damp by good ventilation so far as to maintain always and in all parts of a mine a proportion of this gas below the lower limit of explosiveness belonging to a mixture of air and methane. Good ventilation still remains the best preventive of explosions from fire-damp, and since, even with a rational and well-controlled mine-ventilation, the volumes of air traversing galleries and rooms are liable to vary within wide limits by reason of open doors, falls of rock, or other accidental causes, it follows that but a few thousandths of fire-damp should be left in the normal atmosphere of the mine-workings, so that a considerable

Jan 1, 1894

By Frederick N. Rhines, Robert F. Mehl

Relatively few data have been collected on the rates of diffusion in ternary solid solution systems. In general it does not seem worth while to gather extensive data for such systems until the factors that determine the rates of diffusion in binary systems are better understood. But the rates of diffusion in a ternary system of limited solid solubility, in which the terminal solid solution is in equilibrium with an intermediate phase and may thus be represented as a quasibinary system, represents a case of special interest. In this case, where by reason of the association of the two solute metals in an intermediate phase a special attraction of the two solute atoms may be safely assumed, some interaction of these atoms during simultaneous diffusion in the solvent lattice might be expected. It has frequently been proposed that molecular solid solutions exist in quasibinary and in other ternary (and binary) solid solutions. There is no direct evidence for such solid solutions; arguments based upon the supposed anomaly in certain physical properties1 are hardly important; unexpected density relationships have proved deceptive;2 suggestions of molecular solid solutions have been made on the basis of solution laws in their application to certain systems, but without result;3 attempts to find lattice parameters in the solid solution Al-MgZnz, which cannot be calculated from the separate effects of magnesium and zinc and might therefore be taken as evidence for a molecular aggregation, have given negative results.* Fundamentally, methods for the determination of the state of molecular aggregation in solution depend upon the kinetic behavior of the particles constituting the system. If it could be shown that the two solutes in a quasibinary ternary system diffuse in molecular proportions, despite a radical difference in the separate rates of diffusion of each solute when diffusing alone in the solvent lattice, some basis for the concept of molecular solid solution would be afforded. Freche5 examined the rates of

Jan 1, 1940

By Frederick N. Rhines, Robert F. Mehl

Relatively few data have been collected on the rates of diffusion in ternary solid solution systems. In general it does not seem worth while to gather extensive data for such systems until the factors that determine the rates of diffusion in binary systems are better understood. But the rates of diffusion in a ternary system of limited solid solubility, in which the terminal solid solution is in equilibrium with an intermediate phase and may thus be represented as a quasibinary system, represents a case of special interest. In this case, where by reason of the association of the two solute metals in an intermediate phase a special attraction of the two solute atoms may be safely assumed, some interaction of these atoms during simultaneous diffusion in the solvent lattice might be expected. It has frequently been proposed that molecular solid solutions exist in quasibinary and in other ternary (and binary) solid solutions. There is no direct evidence for such solid solutions; arguments based upon the supposed anomaly in certain physical properties1 are hardly important; unexpected density relationships have proved deceptive;2 suggestions of molecular solid solutions have been made on the basis of solution laws in their application to certain systems, but without result;3 attempts to find lattice parameters in the solid solution Al-MgZnz, which cannot be calculated from the separate effects of magnesium and zinc and might therefore be taken as evidence for a molecular aggregation, have given negative results.* Fundamentally, methods for the determination of the state of molecular aggregation in solution depend upon the kinetic behavior of the particles constituting the system. If it could be shown that the two solutes in a quasibinary ternary system diffuse in molecular proportions, despite a radical difference in the separate rates of diffusion of each solute when diffusing alone in the solvent lattice, some basis for the concept of molecular solid solution would be afforded. Freche5 examined the rates of

Jan 1, 1940

By A. R. Kinkel

The Shasta copper-zinc district of northern California lies in the foothills of the Klamath Mountains at the northern end of the Sacramento Valley. It contains two main areas of base-metal ore deposits, the East Shasta and West Shasta districts shown in Fig. 1. The East Shasta includes the area from the Afterthought mine, near the settlement of Ingot on U. S. highway 299 East, to the Bully Hill mine, on the north side of the Pit River, 9 miles to the north- west. The West Shasta, a well-defined northeast- trending district about 8 miles long and 2 miles wide, west of the Sacramento River, Fig. 2, is the western part of the ore-bearing area formerly known as the Shasta copper belt. Referred to in the older writings as a copper arc, this belt was thought to form a crescent extending entirely around the head of the Sacramento Valley, the convex side to the north. Recent studies by the U. S. Geological Survey in cooperation with the California State Division of Mines show that there are two districts, one at each end of the so-called copper arc, which are distinct in geologic structure and ore occurrences, and that there is only sporadic and unconnected copper mineralization between them.

Jan 2, 1955

By W. M. Rutherford

A knowledge of the limits of miscibility between reservoir oil and possible injection fluids is required for selection of the optimum miscible-injection fluid. Limits of miscibility can be estimated from the results of equilibrium phase-behavior experiments. They can also be determined by means of displacement experiments conducted in a high-pressure sandpack. This paper describes the equipment and procedure which have been developed for determining miscibility conditions by stable displacement. A systematic series of displacements of a West Texas reservoir oil was carried out. The results indicate that, at constant pressure, miscibility is a function only of the pseudocritical temperature of the injection gas. This fact, together with improved experimental methods, makes the displacement technique a rapid, reliable means for determining miscibility conditions. In conjunction with the displacement experiments, phase diagrams were constructed for the oil with dry gas and propane and with dry gas and ethane. Phase behavior of the methane-ethane-propane system was determined at 110°F. The experimental work demonstrates the feasibility of using ethane-rich gases to reduce cost and pressure requirements for miscible displacement. INTRODUCTION In recent years, interest in the miscible displacement of oil by light hydrocarbon mixtures has been high. Many pilot and a few field scale projects have been started.1 These projects have made use of various methods for achieving miscibility: (1) the LPG-slug process, (2) the enriched-gas-drive process and (3) the high-pressure gas-drive process. Some field projects have been successful; the results of others are debatable. In general, projects which have performed best have involved the injection of an appreciable fraction of a pore volume of miscible material. Economical application of miscible displacement depends strongly on the cost of the miscible-injection fluid. If an appreciable fraction of a pore volume of material is required for successful application of these methods, a precise knowledge of the minimum requirements for miscibility in terms of composition of injection fluid is essential. Therefore, reliable experimental methods for determining miscibility conditions are important, and a procedure for estimating these conditions from the composition of the reservoir fluid is highly desirable. The subject of this paper is the problem of determining conditions which result in miscible displacement of oil by light hydrocarbon mixtures. Miscibility conditions can be estimated by means of equilibrium experiments conducted in a PVT cell, or they can be determined by means of high-pressure displacement experiments. This paper describes the equipment and procedure which have been developed for the determination of miscibility by high-pressure displacement experiments. These methods have been applied to the displacement of a West Texas reservoir oil with mixtures of dry gas, ethane and propane. In conjunction with the displacement experiments, triangular phase diagrams have been constructed for mixtures of the oil with dry gas and propane and with dry gas and ethane. The effect of injection-gas composition on conditions for miscible displacement in high-pressure sandpacks and cores has been the subject of several published papers.2-5 The experimental methods used in these investigations were such that displacements were unstable, and the effects of fingering and/or gravity layover are clearly evident in the results. Miscibility conditions were probably correct in spite of the instability phenomena, but the experiments evidently were time-consuming, and limited data were reported. Systematic high-pressure flow studies which would support a correlation of miscibility conditions have not been reported; however, Wilson5 has proposed the use of pseudocritical temperature of the injection gas as a parameter and Benham, et al,6 have based a miscibility correlation on observed and calculated equilibrium data.

By E. S. Leaver

THE purpose of this paper is to describe, in a general way, gold-dredg-ing operations in California, with particular reference to unusual features, including types of deposits and recent attempts to improve the recovery of the gold. DREDGING AREAS The gold-bearing formations that traversed the western slope of the Sierra Nevadas for a north and south distance of some 300 miles furnished the immediate source of the gold found in most of the placer deposits of California.. Erosion through a long period carried the gold, together with various forms of partly disintegrated material, to lower elevations and formed placer deposits. Through the classifying action of water in motion, the coarser gold and heavier material of various kinds were deposited relatively near the source; consequently, in' the higher moun-tain country, old river channels were worked feverishly during the early California gold-rush days because of their high gold content. With the working out of these known high-grade channels, and from the knowledge thus obtained of prehistoric stream beds, drift mining was started and flourished until about 1890. Even today many drift mines are operating with the objective of opening other old Tertiary river channels that have been covered by volcanic flows.

Jan 1, 1937

By G. R. Wilms

In a recent investigation1 on the properties of chromium, and of Cr-10 wt pct W and Cr-5 wt pct Mo alloys at elevated temperatures, it was found that intercrystalline cavities developed in all of these materials during tensile creep at 950°C, and that the cavities led to intercrystalline fracture. There were some interesting differences, however, between the cavities produced in the pure metal and those in the alloys; these differences, moreover, were associated with a difference in ductility. The relevant conditions of creep testing are specified in the captions to Figs. 1 and 3. Chromium showed the presence of quite large intercrystalline cavities, Fig. 1, and these were more or less randomly distributed around the boundaries. The chromium alloys, on the other hand, showed the presence of both small cavities and cracks at the grain boundaries, Fig. 3; it is apparent that the cracks are formed by the linking together of the small cavities. Moreover, the cavities and

Jan 1, 1960

By Morris Muskat

A general theory has been developed for the effect of permeability stratification on the efficiency of the gas-injection phase of cycling operations. It has been applied to three special types of permeability variation; namely, exponential, probability, and linear. In the case of the exponential permeability distribution the effect of areal pattern sweep efficiency was also taken into account. The exponential permeability distribution can be characterized by the ratio of the maximum to minimum permeability, which has been termed the stratification constant. Curves were calculated for the variation in total wet gas recovery and total gas throughflow, to give that recovery to various abandonment limits of the wet gas content in the produced gas, as a function of the stratification constant. The cumulative wet gas recovery decreases monotonically as the stratification constant increases and is generally higher at the lower values of the wet gas content abandonment limits. The total gas throughflow first rises to a maximum as the stratification increases, and then ultimately declines. The effect of the areal sweep pattern efficiency is relatively minor as compared to that of the stratification constant, except in the region of low values of the latter where the formation is substantially uniform. The probability distribution can be characterized by a "variation" parameter varying from o to I as the formation changes from strict uniformity to extreme variability. The curves of total wet gas recovery and total gas throughflow to different abandonment limits of wet gas content versus the variation parameter have the same general characteristics as for the exponential permeability distribution. In the linear permeability distribution the ratio of maximum to minimum permeability also serves as a stratification constant index defining the distribution. The curves of total wet gas recovery and gas throughflow to fixed abandonment limits versus the stratification constant are similar to those for the exponential permeability distribution. However, for the higher values of the stratification constant the recoveries and throughflows do not asymptotically fall to o as in the latter, but approach constant values determined by the abandonment limit of wet gas content in the produced gas. Introduction It is becoming generally recognized that one of the most important factors determining the economic feasibility of cycling operations is the areal continuity and permeability distribution of the producing formation. While the effects of areal variations in permeability, porosity, thickness, and well pattern on the sweep efficiency can be evaluated by electrical model studies,' those due to permeability stratification require separate treatment. Several studies have been reported2,3 on the' influence of permeability variations on the wet gas recovery by cycling. In these, however, discontinuous permeability variations either have been assumed explicitly, or the analysis has been carried through as if they were discontinuous. While, in fact, the actual permeability profiles will undoubtedly be discontinuous, recent develop-

Jan 1, 1949

By O. R. Wagner, R. O. Leach, H. W. Wood, C. F. Harpke

PAN AMERICAN PETROLEUM CORP.TULSA, OKLA. CASPER, WYO A field test has been made in which additional oil recovery was obtained from a previously-waterflooded "oil-wet" sandstone reservoir. This recovery improvement was accomplished by adjusting the reservoir wettability through chemical treatment of the flood water. The test was made in the Muddy sand of the West Harrisburg Unit, Neb. The chemical used, sodium hydroxide, was injected as a slug of dilute caustic solution through a water-injection well. The natural wettability of the reservoir and the chemical requirements for reversing wettability were determined in the laboratory from contact-angle studies using field water and oil samples. Laboratory flood tests with a synthetic system had shown that reversing the wettability of an oil-wet consolidated core would lead to improved oil recovery. The field performance indicates that the mechanism by which increased oil retovery is obtained in the field is the same as that observed in the lahoratory. Laboratory studies indicate that higher ultimate recoveries and decreascd water-injection requirements result when the adjusting agent is added early in the life of the flood. However, a previously waterflooded area was intentiorzally chosen for the field test so that unambiguous conclusions could be made about the effects of chemical injection on wettability and the extent of oil-recovery improvernent afforded by wettability reversal. Forces existing at the fluid-solid and fluid-fluid interfaces in a porous medium have an important effect on oil recovery during a water flood. Modifying these interfacial forces in the reservoir to improve oil recovery has been the object of much research. Several papers' ' have discussed the use of surfactants to lower the water-oil interfacial tension. This paper describes work concerned with improving oil recovery by modifying the forces at the fluid-solid interfaces— that is, by changing the preferential wettability. An earlier paper: presented evidence to show that some reservoir systems could be changed from preferentially oil-wet to preferentially water-wet by the action of simple chemicals added to the water to increase waterflood oil recovery. The process was attractive for further study because it used only inexpensive chemicals and because it called for a gross "wettability reversal" rather than for a precise adjustment. The present paper is an extension of the earlier work. Laboratory flow tests were made using treated water and oil in a consolidated core to determine the amount of additional oil recovery and the producing performance which might be expected from reversing the wettability of an oil-wet reservoir during a flood. A contact-anglc study using water and oil from the Muddy "J" sand of the Harrisburg field, Banner County, Neb., indicated the reservoir to be preferentially oil-wet and susceptible to wettability reversal through chemical injection. Based on these studies, a field trial of wettability-reversal water flooding was initiated. in the Harrisburg field. The primary purpose of the trial was to determine if wettability-reversal flooding would improve oil recovery in an actual field situation. The field trial was also an important test of the laboratory tecnique used to determine the effect on oil recovery of certain wettability manipulation, as well as a test of the contract-angle method of determining reservoir wetra-bility. The paper is presented in two parts. The first part covers the laboratory experiments leading up to the field trial, and the second part covers the field trial. PART I—LABORATORY STUDY The laboratory experiments consisted of displacement tests using an idealized fluid system and of a contact-angle study with crude and water from the Muddy "J" sand of the West Harrisburg Unit, Banner County, Neb. The displacement tests were designed to determine the effects of a particular wettability manipulation, oil-wet to water-wet, on oil displacement in a water flood. The contact-angle measurements were made to determine the natural wettability of the reservoir and to determine if beneficial wetting changes could be brought about by a chemical addition to the flood water. PROCEDURE DISPLACEMENT TESTS The displacement tests were perfornled in a consolidated sandstone core using a refined oil and water. The wetting properties of this system could

By Pope Yeatman

In my experience, perhaps the most interesting problems came up during the testing, prospecting, developing and equipping of the Chuquicamata and Braden Copper Mines in Chile, and it is proposed in this article to give as briefly as possible what some of those problems were, their solutions, and the decisions made as to the different methods to be employed. The romance of mining is still a great lure to the young man who is making a choice of a profession to follow. The thought of travel to strange and out-of-the-way places, the glamor of pioneer life, the excitement of discovery, the constructive work of building something, entirely "from the grass roots up," or of reconstructing a played-out property and making a success of it-all of these phases have a strong appeal and often influence the young man in the choice of mining as a profession. That great engineer, Col. Seeley Wintersmith Mudd, whom we are endeavoring to honor, while having too much common sense to have been materially influenced by the romance of mining, certainly experienced all of the

Jan 1, 1932

By S. L. Payne, J. P. Morris, R. L. Kipp, G. R. Zellars

The activities of iron and nickel in liquid Fe-Ni alloys were determined by measuring the vapor pressures of iron and nickel above the alloys and comparing with the vapor pressures of the pure metals. Nickel was found to deviate negatively from Raoult's law over the entire composition range. Iron behaves ideally down to 0.7 mole fraction but shows negative deviations at lower concentrations. At 1600°C the activity coefficients at infinite dilution are 0.40 for iron and 0.66 for nickel. 1 HE formulation of the conditions of chemical equilibrium between liquid metals and gases or slags is an important application of thermodynamics to pro- cess metallurgy. Usually the metal and slag phases are solutions of several components; and for accurate calculations, it is often necessary to use the activities of the components in place of their concentrations. Data concerning activities, however, are quite meager. The evaluation of the activities of iron and nickel, presented in this paper, is part of a project to determine activities in iron alloys at elevated temperatures.

Jan 1, 1960

By E. Furubayashi, T. Taoka, S. Takeuchi

Recrystallization textures developed from artificial nucleation around indentations were compared with spontaneously recrystallized textures in two rolled 3 pet Si-Fe single crystals with (111)[112] and (100) [011] orientations. Orientation of individual grains in some stages of their growth was also directly determined by a microetch-pit method. In both the crystals, the recrystallization texture was characteristic of each orientation regardless of any nucleation conditions, artificial or spontaneous, though artificially nucleated grains were more randomly oriented in finer stage. These results support the concept that the process of selection of growing grains controls the formation of the prejerred recrystallization texture. Discussion is given on the factors controlling the mobility of grain boundaries. Recrystallization textures are formed through a number of stages which are customarily called by the terms recovery, nucleation, and grain growth. Many experiments have been done to clarify the mech- anism of formation of recrystallization texture but no fully successful explanation has been proposed. The texture consists of oriented grains which nucleate at many sites of the deformed matrix and grow at the expense of the matrix during annealing. The current theories on the formation of recrystallization texture are based on the following two extreme hypotheses: 1) the oriented nucleation theory by Burgers et al.;1, 2 2) the oriented growth theory by Beck et al.3-5

Jan 1, 1968

By Norman Hedley, George Barsky, S. J. Sawinson

The cyanidation of precious-metal ores is a complex chemical process. Numerous reactions occur, some of which cause an undesired consumption of alkali and of cyanide. A knowledge of these reactions, their products, and the factors that influence the rates at which they proceed should be of value in working out the most economical conditions for cyanidation; but at present, much of this knowledge is lacking. This paper is confined to a study of some of the fundamentals of cyanidation. At the start of such an investigation it is necessary to simplify the problem under consideration by eliminating as many variables as possible. The results are then, of course, not immediately applicable to practice, but it is hoped in further work to round out the information and thereby make it of more practical value. For convenience in presentation, the paper has been divided into two parts, one devoted to a study of the reaction between cyanide and gold or silver, the other to a consideration of the factors that determine the rate of dissolution. I. REACTIONS INVOLVED IN DISSOLUTION OF GOLD AND SILVER IN DILUTE CYANIDE SOLUTIONS Ever since the cyanide process for gold and silver extraction was introduced there has been discussion of the equation representing the reactions involved. In undertaking a detailed study of these factors, it was felt that the most logical first step was to determine, if possible, what reactions could theoretically take place when gold and sill-er are dissolved by dilute cyanide solutions. It is possible to determine whether or not a given reaction will theoretically take place by calculating the free energy of the reaction. This free-energy value for any given reaction is the algebraic sum of the free energies of formation of each of the reactants and products, and, if these values are known, the calculation is simple. (A chemical change always involves an energy change and the amount of energy change involved is the factor determining whether a given reaction will take place or how far it will go. In chemistry we consider what is known as the "free energy"; that is, the maximum amount of energy that can be utilized as

Jan 1, 1935

By D. J. Carney, J. Chipman, N. J. Grant

SINCE the beginning of this century it has been known that hydrogen contributes to the porosity of steel and that it is harmful to its mechanical properties. The evidence for this has been largely qualitative. Steel to which hydrogen was purposely added. in sufficient .amounts was shown to be either porous or brittle or both, whereas similar steel of low hydrogen content was shown to be free of porosity and to possess normal physical properties. There have been a considerable number of qualitative experiments of this type. Also, early in this century, a few attempts were made to measure the amount of hydrogen normally dissolved in commercial steels. This was usually done by placing the sample under an inverted liquid column such as mercury and collecting the evolved gas. These attempts, while not successful in measuring actual amounts of dissolved hydrogen gas, were able to prove that this gas will diffuse out of steel at room temperature, and that the amount of hydrogen dissolved is normally very small. On the basis of such qualitative evidence, hydrogen has been and still is blamed for a great number of the troubles encountered in the steel industry. In recent years, partial solutions for many steel-working problems have been obtained. These have led to increased interest in accurate quantitative work on hydrogen in steel, with the expectation that the results might possibly answer a few of the remaining unsolved problems. Commercially, two of the obvious questions which are in need of an answer are: (1) what are the most important sources of hydrogen, and (2) what quantity of hydrogen can be tolerated in various steels? There are many other unanswered questions. To begin to find the answers it seemed logical to start at the beginning of steel production with the liquid metal. Further, it seemed almost imperative to solve first the problems of analysis and sampling of the metal for hydrogen. Once these problems have been solved, it would be possible to answer more of the important commercial problems mentioned above. As a consequence, it was decided to design an analytical apparatus and, upon satisfactory completion of this, to develop an accurate method of sampling liquid metal for hydrogen.

Jan 1, 1951

By S. Shapiro, R. G. Ames

Background Research on the respiratory health of coal miners has focused predominately on the relationship between coal mine dust exposure and ventilatory function impairment (Lapp et al., 1972; Jacobsen, 1976), on the prevalence of coal workers' pneumoconiosis (Lainhart et al., 1969; Morgan et al., 1973), and on coal miner mortality (Ortmeyer et al., 1974; Rockette, 1977). Lesser attention has been paid to the effects of other mining exposures. For example, underground exposure to diesel exhaust emissions (Reger et al., 1980; Ames et al., 1982,1984). An omission in US coal mining research, however, has been identified by the US Office of Technology Assessment (OTA) as the failure to study the effects of inhaled polyvinyl chloride (PVC) thermal decomposition and combustion products (Seltzer, 1979). These products may be released in the mine environment by cable fires, cable explosions, smoldering cables, and conveyor belt fires. In addition to the OTA concern, recent findings of chronic respiratory conditions and other health complications resulting from exposure to PVC decomposition and combustion products in firefighters (Peters et al., 1974; NBS, 1980; NIOSH, 1982; Wallace, 1982), and in survivors of several large scale PVC-fueled fires (Dyer and Esch, 1976; Wallace, 1981, 1982), add immediacy to the concerns. PVC decomposition and combustion PVC decomposition is initiated at temperatures far below ignition (Hartstein and Forshey, 1974; Wallace, 1981). Hence, exposures to decomposition products from smoldering cables may be important health hazards in addition to cable insulation combustion products. Hydrochloric acid (HCL) appears to be the principle toxic substance from the thermal decomposition of PVC since up to 60% by weight is released as HCL (Barrow et al., 1979). HCL is released both as a gas and as an adsorbant on soot particles (Stone et al., 1973), thus allowing penetration of respiratory defenses. In addition, laboratory results indicate that phosgene (carbonyl chloride), a potentially lethal gas, may be produced in significant quantities from electrical arcing of wires covered with PVC insulation (Woolley, 1971; Brown and Birky, 1980). Health concerns related to PVC Toxic effects resulting from high level exposures to PVC pyrolysis and combustion products in animals (Cornish and Abar, 1969) and in humans (Wallace, 1981) is beyond question. Analyses have reported acute, or short-term, health effects resulting from exposure to PVC decomposition and combustion products (Peters et al., 1974; Polakoff et al., 1975). Recently, however, several studies have found that acute effects are often followed first by apparent healing, and then by delayed chronic effects. This pattern of consequential respiratory involvement among persons involved in major PVC-fueled fires has been noted in firefighters, specifically the 1975 New York Telephone Exchange fire (Dyer and Esch, 1976; Wallace, 1982), and the survivors of the 1977 Beverly Hills Supper Club fire (Wallace, 1981). An obstructive syndrome (low FVC and FEV1) was seen in 15% of workers three months following fighting a PVC-fueled fire (Colardyn et al., 1976). Long-term respiratory symptoms seen in studies of survivors of PVC-fueled fires include the bronchitis symptoms of cough and phlegm, and lung dysfunction (Wallace, 1981). Additional support for the thesis of longer-term respiratory effects resulting from PVC-fueled fires is derived from the finding that four persons who initially survived the Beverly Hills Supper Club fire died within nine months of the fire of severe respiratory impairment (Wallace, 1981).

Jan 1, 1986

By Richard V. Ageton

Salt bodies in the form of rolls, horses (sometimes called horsebacks), folds, wants and pinches1 have been encountered while driving entries and mining out rooms during the development of the potash mines in New Mexico. Superficially these sporadic salt occurrences appear to be much alike, but closer examination reveals individual characteristics, and after four years of observation it seems possible to divide them into three general groups that may tentatively be called "depositional," "erosional," and "structural." The data collected are not yet sufficient to permit forecasts of their probable location, so that the annoyance of having to mine salt instead of potash could be avoided or lessened. However, the information so far available appears to throw some light on the occurrence of the sylvite2 bed now being mined, and it is as a progress report that the writer presents the results of his observations. The mines of the United States Potash Co. and the Potash Company of America are about 20 miles northeast of Carlsbad, in Eddy County, N. M. They are on the southwestern flank of the Permian salt basin, which underlies western Texas, Oklahoma and Kansas, south-central Nebraska, southeastern Colorado and eastern New Mexico. The cuttings from many oil wells and the cores from the potash tests drilled in this basin indicate that this salt series approached its greatest thickness (about 4000 ft.) in the southeastern part of New Mexico and the adjoining portions of Texas, and that the most advanced stages of

Jan 1, 1938

By Richard V. Ageton

Salt bodies in the form of rolls, horses (sometimes called horsebacks), folds, wants and pinches1 have been encountered while driving entries and mining out rooms during the development of the potash mines in New Mexico. Superficially these sporadic salt occurrences appear to be much alike, but closer examination reveals individual characteristics, and after four years of observation it seems possible to divide them into three general groups that may tentatively be called "depositional," "erosional," and "structural." The data collected are not yet sufficient to permit forecasts of their probable location, so that the annoyance of having to mine salt instead of potash could be avoided or lessened. However, the information so far available appears to throw some light on the occurrence of the sylvite2 bed now being mined, and it is as a progress report that the writer presents the results of his observations. The mines of the United States Potash Co. and the Potash Company of America are about 20 miles northeast of Carlsbad, in Eddy County, N. M. They are on the southwestern flank of the Permian salt basin, which underlies western Texas, Oklahoma and Kansas, south-central Nebraska, southeastern Colorado and eastern New Mexico. The cuttings from many oil wells and the cores from the potash tests drilled in this basin indicate that this salt series approached its greatest thickness (about 4000 ft.) in the southeastern part of New Mexico and the adjoining portions of Texas, and that the most advanced stages of

Jan 1, 1938

By H. Biloni, H. R. Bertorello

GruZLESKI and winegard1 have recently reported on the origin and development of the cellular substructure in Sn-Cd eutectic unidirectionally grown with different amounts of constitutional supercooling (CS). This communication deals with the results obtained in a parallel study on the instability of a plane interface in Al-Cu eutectic unidirectionally grown. Similarities as well as differences with the results of these authors1 will be presented. A1-Cu eutectic alloy ingots of 99.999 pct purity were grown unidirectionally under different G/R ratios where G = thermal gradient in the liquid, R = solidification rate. The ingots were cut in slices perpendicular to the solidification axes and the substructure studied on parallel sections following the sense of growth. It was generally found that the last part of the ingot to solidify presented a well developed colony substructure as a result of impurity build up and constitutional supercooling. The results obtained were: 1) When the structure was observed with low niagnification (of the order of 150 to 300 times) the first instabilities were observed at the grain boundaries and node-like structures formed at the junctions of the growth-induced boundaries, as reported by Gruz-leski and Winegard.1 Inside the grains the first signs of instability appear later and correspond to the type shown in Fig. 1; this is a two dimensional cell substructure. ' 2) Figs. 2 and 3 correspond to the evolution from a two dimensional substructure to a cellular type. In the A1-Cu eutectic the boundaries of the two dimensional cell are always perpendicular to the laniellaes instead of parallel as in the Sn-Cd eutectic. 1

Jan 1, 1970

By Carl J. Christensen

This paper presents the development of diamond coring of the Weber sand section in the Rangely Field, Colorado. The description and operation of the diamond-coring equipment is included as well as the economics and results obtained by its use. Diamond coring is compared with the other methods used for drilling the Weber sand. Two types of diamond coring are discussed. The first and the one used most extensively is the regular 6 ?x 3¾-in. diamond bit and bottom hole 50-ft barrel. The second type, which has also been used successfully by Stanolind, consists of a 4 13/16 x 2 11/32-in. cutting bit and reverse circulation coring equipment. The first type will be referred to as regular or conventional diamond coring while the latter type will be referred to as reverse circulation diamond coring. Introduction Diamond coring has been used for many years in mines, quarries, surface coring at dam sites, laboratory work, and so on, but, until recently, had never been used very extensively in coring oil sands and other oil-bearing strata. It was demonstrated early in its development that hard forma-tions could be cut rapidly and that core recoveries far exceeded those obtained with conventional hard rock bits and quite often 100 pet recovery was obtained. However, the poorly constructed diamond-coring equipment and resulting high costs of early diamond coring slowed down its progress. Early in the development Of the Rangely Weber field, Rio Blanco County, Colorado, the Rangely Engineering Committee selected key wells that were to core the Weber section in its entirety. These cores were to be analyzed and various sections tested to gather sufficient information so that accurate reservoir studies could be made. The number of wells selected were kept at a minimum inasmuch as the productive Weber section, which is found at an approximate depth of 6000 ft, is thick, being as much as 600 to 700 ft on top of the structure. The Weber section is also comparatively hard to drill. For instance, one well took 60 days to core 490 ft of Weber sand with conventional coring equipment. It was noticed, however, that Core Labora-verse diamond plug cutter could quickly cut a plug from. one of these hard cores. This fact led to the serious consideration of diamond coring the Weber sand. The first diamond coring at Randy was performed by Stanolind in August 1946 andl although we experienced some difficulties, the results definitely indicated that diamond coring would be successful at Rangely for .coring the Weber sand. As more wells were cored and the equipment improved somewhat, diamond coring became less expensive than drilling the Weber sand with the conventional rock bit. In less than one Year diamond coring has definitely Proved its usefulness in oil-field drilling operations in the Rocky Mountain area where formations quite often drill very hard. The practice of spot coring in hard oil-bearing formations with conventional coring equipment is giving way diaimond coring of the entire sections, thus givng an operator the complete picture.

Jan 1, 1948

By Carl J. Christensen

This paper presents the development of diamond coring of the Weber sand section in the Rangely Field, Colorado. The description and operation of the diamond-coring equipment is included as well as the economics and results obtained by its use. Diamond coring is compared with the other methods used for drilling the Weber sand. Two types of diamond coring are discussed. The first and the one used most extensively is the regular 6 ?x 3¾-in. diamond bit and bottom hole 50-ft barrel. The second type, which has also been used successfully by Stanolind, consists of a 4 13/16 x 2 11/32-in. cutting bit and reverse circulation coring equipment. The first type will be referred to as regular or conventional diamond coring while the latter type will be referred to as reverse circulation diamond coring. Introduction Diamond coring has been used for many years in mines, quarries, surface coring at dam sites, laboratory work, and so on, but, until recently, had never been used very extensively in coring oil sands and other oil-bearing strata. It was demonstrated early in its development that hard forma-tions could be cut rapidly and that core recoveries far exceeded those obtained with conventional hard rock bits and quite often 100 pet recovery was obtained. However, the poorly constructed diamond-coring equipment and resulting high costs of early diamond coring slowed down its progress. Early in the development Of the Rangely Weber field, Rio Blanco County, Colorado, the Rangely Engineering Committee selected key wells that were to core the Weber section in its entirety. These cores were to be analyzed and various sections tested to gather sufficient information so that accurate reservoir studies could be made. The number of wells selected were kept at a minimum inasmuch as the productive Weber section, which is found at an approximate depth of 6000 ft, is thick, being as much as 600 to 700 ft on top of the structure. The Weber section is also comparatively hard to drill. For instance, one well took 60 days to core 490 ft of Weber sand with conventional coring equipment. It was noticed, however, that Core Labora-verse diamond plug cutter could quickly cut a plug from. one of these hard cores. This fact led to the serious consideration of diamond coring the Weber sand. The first diamond coring at Randy was performed by Stanolind in August 1946 andl although we experienced some difficulties, the results definitely indicated that diamond coring would be successful at Rangely for .coring the Weber sand. As more wells were cored and the equipment improved somewhat, diamond coring became less expensive than drilling the Weber sand with the conventional rock bit. In less than one Year diamond coring has definitely Proved its usefulness in oil-field drilling operations in the Rocky Mountain area where formations quite often drill very hard. The practice of spot coring in hard oil-bearing formations with conventional coring equipment is giving way diaimond coring of the entire sections, thus givng an operator the complete picture.

Jan 1, 1948