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By Robert Baker

IT has been demonstrated in the laboratory by A. J. Phillips1 that a transformation or conversion from beta directly to alpha may take place in a brass of 61 to 62.5 per cent copper content. The completion of the transformation is dependent on a rapid rate of cooling from the all-beta field through the alpha + beta range to the alpha field. Phillips states that in a slowly cooled alloy containing 62 per cent copper and 38 per cent zinc the copper content of the beta is progressively decreased from 62 to 56 per cent by precipitation of alpha. Rapid cooling tends to prevent the separation of alpha with a copper content of more than 62 per cent by reducing to a minimum the time required for passing through the alpha + beta range. Upon crossing beyond the (alpha + beta.)/(alpha) boundary to the all-alpha region below, the material is transformed from beta to alpha. It is essential that there be no change in composition. Phillips obtained his results by quenching a 62:38 copper-zinc alloy from 850° C. in iced brine at -8° C. No reference to the occurrence of this transformation in a manufacturing process has been found in the literature. An investigation of the microstructures of a number of hot forgings made from leaded brass rods yielded one forging in which this striking conversion from beta to alpha had occurred. The purpose of this paper is to describe the transformation and certain conditions under which it may occur during the hot pressing of brass. The conversion was noted in a shape forged from a leaded brass rod, the composition of which was: Cu, 60.26 per cent; Zn, 37.86; Pb, 1.88. In this study the lead content was disregarded and the alloy was considered to be equivalent to an alloy of 61.40 per cent copper and 38.60 per cent zinc (98.12 parts = 100 parts). The possibility that the lead might obstruct or accelerate the precipitation of alpha was not studied. The lead appears as black globules in the photomicrographs and has a negligible solubility in the alloy.

Jan 1, 1931

By H. D. Outmans

The author applies the theory of hydrodynamic stability to fluid flow in porous media and concludes that the displacement of miscible liquids is stable if the stability coefficient, as defined by Eq. 19.2 or Eq. 27.0, is positive. The conclusion is invalid, however, since it is based on a faulty argument. To demonstrate this, the reader is referred to Eqs. 4.1 through 4.5 of the paper which describe, in differential form, the first-order disturbances c, u, v, w and p. In these same equations, cx, cz, gl, g3 and are functions of the stable concentration c. This concentration c is known and depends on x, z and t (the author assumes cy = 0). It follows that cx, cz, gl, g3 and µ are also functions of x, z and t. With this in mind, we turn to Eqs. 8.1 through 8.5 which were derived from Eqs. 4.1 through 4.5 by substituting Eq. 6.0. The significance of this substitution is that the author thereby limits the solutions of Eqs. 4.1 through 4.5 to equations of the form of Eq. 6.0. Eqs. 8.1 through 8.5 represent an infinite linear system with five unknowns: c, u, v, w and p. The coefficients cx, cz, gl, g3 and µ in this system are known at each point and at each instant; the coefficients containing derivatives of f are unknown. If this infinite linear system in c, u, v, w and p is to have a nontrivial solution, then it is indeed necessary (as the author states) that the determinant of the coefficient matrix of Eqs. 8.1 through 8.5, i.e., ( A 1, be equal to zero. This condition, however, is not sufficient. A non-trivial solution exists if, and only if, the rank of the coefficient matrix of the entire infinite system is smaller than five. In other words. all minors of order five must vanish and only if all the coefficients in Eqs. 8.1 through 8.5 are constant is this equivalent to the condition |A| =0. Constant coefficients means that gl, g3 and µ, for instance, are constant; and, since they depend on c it follows that c must be constant. We conclude that the condition I A I = 0, on which the author bases his calculations, is necessary and sufficient for a nontrivial solution only if the concentration c is constant. In other words, the author does not investigate the stability of a miscible displacement but, rather, only the stability of the flow of a homogeneous liquid. Using the initial condition and the fact that the coefficients are constant, we find

By Lewis W. MacNaughton

The North Texas district, as herein defined, includes the counties of Archer, Baylor, Clay, Cooke, Foard, Hardeman, Knox, Montague, Wichita, and Wil-barger. This area covers generally the crest and south flank of a system of buried mountains known as the Red River uplift. The oil and gas accumulations along this feature are in traps, which, although localized by structures incident to the regional uplift, are usually modified by stratigraphic changes in the sediments. Excepting the fields in southeastern Baylor, southern Archer, and southwestern Clay Counties, all the fields within the district are on this Red River uplift. These exceptions, which have the same type of oil and gas accumulation as the other fields, are on the extreme north end of the Bend arch, which is a broad anticline plunging northward from the Llano uplift in central Texas to Archer County. The larger part of past oil and gas production has come from Pennsylvanian strata, with less important amounts from the Permian, and minor but increasingly important quantities from the Ordovician. Developments during 1940 The encouraging outcome of exploration and development in Montague and Cooke Counties and generally greater activity throughout the district resulted in the drilling of some 1700 wells during 1940, about 350 more wells than were drilled in 1939. Approximately 1250 of these tests were completed as oil wells. Production likewise increased during I940 to the extent of 8 million barrels more than the 25 1/2 million barrels produced in 1939. In spite of this large increase in production, known oil reserves again increased substantially. As is usually characteristic of this district, the new reserves were from a large number of fields, none of which were of such magnitude as to be important to the oil industry. Nevertheless, the Fargo field, Wilbarger County, deserves mention as one of the more important discoveries in this district during 1940. Following seismic surveys, the hmerada Petroleum Corporation located its No. I Goodpasture in sec. 35, block IS, H. and T. C. R. R. Co. survey, and drilled it to a total depth of 6717 ft. This well was completed in July 1940 through perforations in the casing from a pay between 3230 and 3252 ft. for an initial production of 241.5 bbl. on an 8-hr. pumping test. Other potential producing horizons were found in the Pennsyl-vanian at depths of 3960 to 3995 ft., 4208 to 11.234 ft., 4407 to 4422 ft., and in the Ordovician at 6300 ft. Wells completed to date in the several Pennsylvanian horizons have an average daily potential of 600 bbl. of oil. Although no wells have yet been completed in the Ellenburger dolomite (Ordovician), the discovery well swabbed I5 bbl. per hour from this formation before plugging back for completion in an upper horizon.

Jan 1, 1941

By Lewis W. MacNaughton

The North Texas district, as herein defined, includes the counties of Archer, Baylor, Clay, Cooke, Foard, Hardeman, Knox, Montague, Wichita, and Wil-barger. This area covers generally the crest and south flank of a system of buried mountains known as the Red River uplift. The oil and gas accumulations along this feature are in traps, which, although localized by structures incident to the regional uplift, are usually modified by stratigraphic changes in the sediments. Excepting the fields in southeastern Baylor, southern Archer, and southwestern Clay Counties, all the fields within the district are on this Red River uplift. These exceptions, which have the same type of oil and gas accumulation as the other fields, are on the extreme north end of the Bend arch, which is a broad anticline plunging northward from the Llano uplift in central Texas to Archer County. The larger part of past oil and gas production has come from Pennsylvanian strata, with less important amounts from the Permian, and minor but increasingly important quantities from the Ordovician. Developments during 1940 The encouraging outcome of exploration and development in Montague and Cooke Counties and generally greater activity throughout the district resulted in the drilling of some 1700 wells during 1940, about 350 more wells than were drilled in 1939. Approximately 1250 of these tests were completed as oil wells. Production likewise increased during I940 to the extent of 8 million barrels more than the 25 1/2 million barrels produced in 1939. In spite of this large increase in production, known oil reserves again increased substantially. As is usually characteristic of this district, the new reserves were from a large number of fields, none of which were of such magnitude as to be important to the oil industry. Nevertheless, the Fargo field, Wilbarger County, deserves mention as one of the more important discoveries in this district during 1940. Following seismic surveys, the hmerada Petroleum Corporation located its No. I Goodpasture in sec. 35, block IS, H. and T. C. R. R. Co. survey, and drilled it to a total depth of 6717 ft. This well was completed in July 1940 through perforations in the casing from a pay between 3230 and 3252 ft. for an initial production of 241.5 bbl. on an 8-hr. pumping test. Other potential producing horizons were found in the Pennsyl-vanian at depths of 3960 to 3995 ft., 4208 to 11.234 ft., 4407 to 4422 ft., and in the Ordovician at 6300 ft. Wells completed to date in the several Pennsylvanian horizons have an average daily potential of 600 bbl. of oil. Although no wells have yet been completed in the Ellenburger dolomite (Ordovician), the discovery well swabbed I5 bbl. per hour from this formation before plugging back for completion in an upper horizon.

Jan 1, 1941

By K. Sassa, I. Ito

The dynamic principal stresses induced within rock by an explosion under con fined conditions are analyzed for the case of blasting with one free face by applying the values of measured radial displacement, particle velocity and so on to equations derived from the theory of elasticity. The dynamic stresses on the free face are also calculated from the strain measured by wire strain gauges affixed on the free face. Some results obtained are briefly: 1) The maximum stress on the free face appeared at the intersection between the free face and the burden, and its magnitude was about twice as large as the magnitude of the tangential tensile stress imparted by the incident stress wave within the range related to the breakage by blasting. 2) The maximum value of the compressive stress near the free face was decreased due to the existence of the free face, while that of the tensile stress was increased. 3) At any point near the free face, the directions of the principal stresses in the r? plane using spherical coordinates with the origin at the center of the spherical charge, changed with time except in the direction of the burden. However, at another point near the explosion point where the principal stresses were mainly those stresses caused by the initial longitudinal wave, the directions of the principal stresses coincided with those of the coordinate used. 4) The maximum value of the tensile stress in the F direction was larger than those in the re plane at and near the free face. 5) The tensile stress caused by the Hopkinson effect appeared only near the burden. 6) It is presumed from the results of stress analysis that radial cracks will be produced in the rock mass near an explosion point, but with the approach of the free face, the directions of cracks curve towards a direction parallel to the free face. INTRODUCTION In order to investigate the mechanism of rock breakage by blasting, it is considered to be very im- portant to know how the stresses are generated and distributed within the rock by explosion of a confined charge. As part of a research program concerning the mechanism of rock breakage by blasting, the authors have already published papers on the detonation pressure produced at the inner surface of the charge hole1 and on the behavior of the dynamic stresses within rock caused by an explosion in the case where no free face existed.' In this study the dynamic stresses on and near the free face have been investigated for the case of blasting with one free face. The mechanism of rock breakage in blasting is discussed in the light of these studies.

Jan 1, 1967

By J. J. Beeson

Page I. PrimaRy MineRalization............................................ 356 1. Introduction..................................................... 356 a. Scope of Work............................................... 356 6. Acknowledgments............................................ 357 c. The Bingham Mining District.................................. 357 d. General Geology.............................................. 357 e. The Utah Copper Mine....................................... 376 f. Field and Laboratory work.................................... 376 2. The Quartz-Monzonite.............................................. 377 3. The Pegmatite Veins.....:.•..............................:........ 378 4. The High-Temperiture Veins.........................-.............:379 5. The Early Hydrotherma! Period.:......................'............ 380 6. The Late Hydrothermal Period................................:.... 385 II. Seconuabx EnricuMENT............................................. 386 . 1. Author's Note;..... ;............................................ 386 2. Factors Governing Enrichment.....................................: 387 3. The Enrichment.................................................... 387 4. The Covellite Enrichment.; .:; ; : .:. :..:.............:................ 388 a. The Capping above the Covellite Ores:....:....................... 388 b. Conclusions Drawn. from a Study of the Capping and the Covellite ; Ores....,.............................................:.....,.' 392 c. Covellite Enrichment at Depth......:......................... : : 392 5. The Chalcocite Enrichment...................................... ; 394 a. The Carbonates in the Capping above .the Chalcocite Ores...:..: .. 394 ' b. The Formation of Chalcocite..:.:. :......:..'...........,......' 394 . 6. Secondary Chalcopyrite and Bornite.............................i ..., . 395 111.- Conclusions as to the Formation.oF the ImpoRtant Sulphides in the Disseminated ORes........................................,.......... 400 I. Primary MiNeRalization 1. Intrdtiction a. Scop. e .of Work.. first part bf, this paper deals with the country rock, its pegihatitic, pneumatolytic', and hydrothermal altektions; also, the effect of magnetite on the deposition of the primary chalcopyrite and pyrite.

Jan 1, 1916

By C. C. Furnas

IT is well known that particles of different sizes are not distributed evenly throughout the average charge in an iron blast furnace. Just how great the disparity in particle size in different parts of a single plane in a furnace may be is indicated by the results of some recent investigations1 conducted by the Bureau of Mines on a furnace operating on Lake ores. The wide variations found in gas velocity, gas composition, and temperature from the periphery to the center of the upper charge column were caused by the great variation in particle size of the raw materials used and were also greatly influenced by the methods of charging. This paper summarizes the results of an investigation of the influence of different methods of charging and of the treatment of raw materials upon the size distribution of the solid particles in the blast furnace. A more complete report will appear later as a Bureau of Mines technical paper.

Jan 1, 1929

By H. T. Kennedy

The fact that intrusion of water into oil wells can be prevented by treating the sand adjacent to the well seems to have been only recently recognized. Swan1 mentions the process of solidifying naphthalene in strata. R. Van A. Mills2 recommends the use of materials such as sodium silicate and sodium carbonate, which react with oil-field water to form solid plugging agents. When a well is drilled in a new field the oil sands are found essentially devoid of water (Fig. 1). Unless a completely impermeable break exists over wide areas in the field, no water is found above the lower limit of the oil zone and no oil is found below the upper limit of the water zone. After considerable oil has been taken from the well, however, it is almost universal experience that water intrusion occurs. This intrusion may be of two kinds. The water may follow a path parallel to the bedding planes of the producing formation through loose streaks in the pay sand, as shown in Fig. 2, or the water level of the field may rise and enter the well by coning (Fig. 3). Water entering from the side is called "edge water," and that coming in from the bottom is called "bottom water.'' Effectiveness of any method for shutting off water depends not only on the effective treatment of the sand adjacent to the well but on

Jan 1, 1936

By H. T. Kennedy

The fact that intrusion of water into oil wells can be prevented by treating the sand adjacent to the well seems to have been only recently recognized. Swan1 mentions the process of solidifying naphthalene in strata. R. Van A. Mills2 recommends the use of materials such as sodium silicate and sodium carbonate, which react with oil-field water to form solid plugging agents. When a well is drilled in a new field the oil sands are found essentially devoid of water (Fig. 1). Unless a completely impermeable break exists over wide areas in the field, no water is found above the lower limit of the oil zone and no oil is found below the upper limit of the water zone. After considerable oil has been taken from the well, however, it is almost universal experience that water intrusion occurs. This intrusion may be of two kinds. The water may follow a path parallel to the bedding planes of the producing formation through loose streaks in the pay sand, as shown in Fig. 2, or the water level of the field may rise and enter the well by coning (Fig. 3). Water entering from the side is called "edge water," and that coming in from the bottom is called "bottom water.'' Effectiveness of any method for shutting off water depends not only on the effective treatment of the sand adjacent to the well but on

Jan 1, 1936

By James P. Roe

Steel has occupied such a prominent position in most minds during the last thirty years, particularly since the introduction of the basic open-hearth process (by which the field from which the raw material could be obtained has been so widened), that little attention has been made to improvements in puddling iron. In fact, the general tendency seems to have been to accept the prediction that puddled iron is doomed. Events have in a measure justified such a forecast, due in large part to the introduction of mechanical appliances and operations with large units in the manufacture of steel, from which much lower costs have resulted. But this general tendency has met checks in certain directions. This is notably the case where the finished product is a welded one, or is subject to oxidation, to shock or to vibration; and, as far as the writer's observation goes, the bond (which is largely a mechanical one) is not as close and lasting between steel and tin or zinc as between iron and the same materials. The field still open for puddled iron is, therefore, a large one, provided the low costs of steel-manufacture can be approached. The process of puddling is one of the most interesting in the metallurgy of iron, as the reactions and the changes effected are apparent. The subject has had the strongest fascination to the writer from boyhood, and has led, not unnaturally, to a close study, which long ago resulted in the conviction that it could be successfully carried out with large units and by mechanical means. That others have also drawn these conclusions is shown by many undertakings, though there have been few such attempts during the last twenty-five or thirty years. Puddling cousists, essentially, in the removal of most of the carbon and silicon, and part of the phosphorus and sulphur

Jan 1, 1903

By Norman D. Fitzgerald

The growth of domestic requirements for motor fuel has been phenomenal, rising year after year in a fashion almost unique among commodities, resisting depressions and forging rapidly ahead in times of prosperity. Consumption advanced from 226 millions of barrels in 1925 to 522 millions of barrels in 1938; or 130 per cent. The economic influences generating and sustaining this demand are of vital concern to the petroleum industry. The general factors affecting utilization of motor fuel are well known but it is the purpose of this paper to employ the recently developed technique of economic dynamics to describe them mathematically. Such problems in economic analysis are complicated by the freedom of all the variables to fluctuate, their mutual interdependence, changing incidence upon one another, and the nonquantitative character of some of them. Economic quantities and relationships, unlike those of the physical world, are continuously changing and this dynamic characteristic is both a distinguishing and confusing feature in economic research. The complexities of the problems require application of the analytical devices of mathematical statistics to uncover the probable relationships between factors. The procedure employed is to formulate a logical relationship linking the dependent to the independent variables, and then simultaneously, rather than sequentially, determine their separate effects by multiple correlation. This transformation of common knowledge to quantitative terms makes it possible to measure the probable effects of changing conditions upon requirements, assisting in the sound interpretation of economic policies. The utility of the results of such dynamic analysis is in sharp contrast to the sterility of the trends and other simple empiricisms of descriptive statistics. It is not intended in this study to throw light on the reasons why any motor fuel at all is consumed; but to discover relationships explaining why more was consumed at one time than at another. Specifically the problem is confined to the measurement of the influences of statistically

Jan 1, 1940

By Norman D. Fitzgerald

The growth of domestic requirements for motor fuel has been phenomenal, rising year after year in a fashion almost unique among commodities, resisting depressions and forging rapidly ahead in times of prosperity. Consumption advanced from 226 millions of barrels in 1925 to 522 millions of barrels in 1938; or 130 per cent. The economic influences generating and sustaining this demand are of vital concern to the petroleum industry. The general factors affecting utilization of motor fuel are well known but it is the purpose of this paper to employ the recently developed technique of economic dynamics to describe them mathematically. Such problems in economic analysis are complicated by the freedom of all the variables to fluctuate, their mutual interdependence, changing incidence upon one another, and the nonquantitative character of some of them. Economic quantities and relationships, unlike those of the physical world, are continuously changing and this dynamic characteristic is both a distinguishing and confusing feature in economic research. The complexities of the problems require application of the analytical devices of mathematical statistics to uncover the probable relationships between factors. The procedure employed is to formulate a logical relationship linking the dependent to the independent variables, and then simultaneously, rather than sequentially, determine their separate effects by multiple correlation. This transformation of common knowledge to quantitative terms makes it possible to measure the probable effects of changing conditions upon requirements, assisting in the sound interpretation of economic policies. The utility of the results of such dynamic analysis is in sharp contrast to the sterility of the trends and other simple empiricisms of descriptive statistics. It is not intended in this study to throw light on the reasons why any motor fuel at all is consumed; but to discover relationships explaining why more was consumed at one time than at another. Specifically the problem is confined to the measurement of the influences of statistically

Jan 1, 1940

By C. V. Milikan

Allocation of allowed production in a prorated field by the use of bottom-hole pressures is a method which is sound in theory. Thus far it has had limited application because the experience in correlating bottom-hole pressures with the depletion of wells or fields is not sufficient to interpret all the pressure changes. With additional data and more general knowledge of bottom-hole pressures their use in proration will probably become common. Bottom-hole pressure is the pressure at or near the bottom of a well. It is usually determined at the face of the producing horizon. Bottom-hole pressure measured while the well is producing, may be called the bottom-hole producing pressure or bottom-hole flowing pressure. If the well has been shut in or shut down long enough for the pressure in the producing horizon within the drainage area of the well to equalize, it may be called the reservoir pressure. The allowable production from a prorated field may be allocated to the individual wells or leases by three methods: 1. Bottom-hole producing or flowing pressures. (a) The potential capacity of a well to produce. (b) A uniform differential pressure while producing at the allowed rate. 2. Reservoir pressures. 3. A combination of bottom-hole producing pressures and reservoir pressures. In most prorated fields the allowed production is allocated to the individual wells or leases in proportion to their individual potentials. This method is based on the theory that there is a direct relationship between the permeability and the porosity of the reservoir. More directly stated it means that there is a direct relationship between the amount of oil in the reservoir and the rate at which it will move through the reservoir. While in general this relationship is true, it may vary considerably in different wells. Furthermore, in many wells the capacity of the reservoir to deliver oil to the well is greater than the capacity of the flow string to deliver oil to the surface. It is especially true where the potential is determined by flowing through tubing or by pumping.

Jan 1, 1933

By Thomas Egleston

The copper-bearing rocks of Lake Superior are composed of a series of metamorphic rocks, comprised under the names of amygdaloid and conglomerate, in which the copper and silver found with them are pseudomorphs. These rocks, generally, have Well-defined walls which cause them to separate easily. Generally, the country rock is sterile, but it occasionally rises into the copper-bearing rock, and then carries copper. Usually, the amygdaloids carry copper, and the greenstones or melaphyres which encase them do not. There is a very generally received opinion that the copper in these beds occurs in shoots. This does not appear to be proved, though the opinion seems to have some foundation from the experience of the Calumet & Heela Mine, where a body of poor rock has been left, which, on the mine map, shows a general direction. The theory may be true of that individual mine, but too little work has been done in the other mines to draw any decided conclusion. The copper is very unequally disseminated in the rock, if any given piece be taken as an example, but, if the whole copper-bearing series be considered, its distribution is uniform. It may prove that there are certain directions in which the copper has been deposited more abundantly than in others, and these may be found to correspond with certain geological causes, but up to the present time the knowledge gained is not sufficient to warrant any general conclusion. These rocks are supplemented by a series of true fissure veins, of which there are several systems, making the amount of native copper very large. Unfortunately, except in the fissure veins, known as " mass-mines," the copper is so scattered through the rock, and is in such a fine state of division, that, although it is not always difficult to mine, it is always difficult to dress it sufficiently to make it pay. The metal is so unifornily distributed throngh these copper-bearing rocks that detached pieces, called " float," are found in digging on almost any land in the country. These pieces vary from very small fragments, weighing not more than a few ounces, up to many pounds. In one instance, in making an excavation for a cellar of a

Jan 1, 1879

By C. R. Kyle, R. L. Perrine

A transparent model of a reservoir has been used to study some characteristics of instability in miscible displacement. The linear model dimensions are 1/4 in. x 91/2 in. x 10 ft. The model is packed with spherical glass beads. Thee groups of experiments have been performed. The objectives were to measure, respectively, the rate of growth of the transition zone, flow velocity variations in the transition zone, and the effect of a graded viscosity zone on stability. All experiments were compared, where possible, with theory. The transition zone grew almost linearly with distance traveled, regardless of flow rate, where adverse viscosity ratios were used. At very adverse viscosity ratios and large distances traveled, some reduction below linear growth was noted. This could be attributed to the effects of mixing. General similarity in flow pattern was commonly shown in different tests, although exceptions occurred at the higher viscosity ratios. Injection of tracer spots permitted direct experimental measurement of velocity variations. Statistical methods were used to compare observed velocity variations with recently published theories. Surprisingly good agreement with some theoretical predictions was obtained. In the experiments using an initially graded viscosity zone, macroscopic stability was reached before predicted by theory. Under conditions theoretically considered to be slightly unstable, any fingering tendency was too slight to become observable within a 10-ft long system. The general correlation of all experiments with published theory was good, and suggests that theoretical predictions can be extended to reservoir problems. INTRODUCTION Early laboratory studies of miscible displacement demonstrated the high recovery efficiency possible with this method. Linear laboratory models showed that, under some circumstances, all in-place hydrocarbons could be recovered using as little solvent as 5 per cent of the pore volume. These results led to a series of pilot field projects. Under realistic conditions, however, other laboratory studies showed that a small solvent bank may not recover much more oil than a conventional gas drive. The cause of this lack of efficiency is unstable viscous fingering. The size of the solvent bank required to give optimum recovery is, therefore, a question of great economic significance. The object of the experiments described in this paper was the quantitative measurement of unstable flow parameters, the verification of present theories on the miscible displacement process, and correlation of these theories with ex peri mental observation. Of the theories which have been advanced, those by Dougherty, Koval and Perrine show promise of predicting reservoir performance with reasonable accuracy.l-7 The present experiments were correlated, where possible, with the theories of Koval and Perrine. Dougherty's theory was not used because of the additional computational difficulty it presented and the belief that no further information would result. EXPERIMENTAL EQUIPMENT A transparent reservoir model, consisting of a vertical reinforced plexiglass column, was used for the experiments. The column was packed with glass beads, which served as the porous medium. To induce a known velocity disturbance in the flow, a double cosine wave restriction in the transverse cross-section was placed at the top of the column. To mark the flow field and provide a means of measuring the local fluid velocity, a dye-spot injection system was provided. The column was 10 ft high by 1/2 in. wide by 1/4 in. deep. The cosine restriction was placed 16 in. from the top of the column. The glass beads were smooth and spherical and had a mean diameter of 0.0102 cm. Liquids entered the top of the column through a manifold allowing three points of entry (left, center, and right, or any combination of these). A positive-displacement pump with variable-speed drive was used to control liquid flow rates. The pump transferred viscous oil from a reservoir to an accumulator, which displaced the test liquid into

Jan 1, 1966

THOSE MARKED THUS * ARE MEMBERS, MARKED THUS ?ARE ASSOCIATES. THESE SIGNS DOUBLED INDICATE LIFE MEMBERS AND ASSOCIATES RESPECTIVELY. THE FIGURES AT THE END OF THE ADDRESS INDICATE THE YEAR OF ELECTION. HEAVY-FACED TYPE SIGNIFIES HONORARY MEMBERSHIP. *AARONS, J. BOYD, Vivian Gold Mining Co., Ltd., Harris, West. Australia. '05 *ABADIE, EMILE R., Cons. and Min. Engr., 214 Union Savings Bank Bldg., Oakland, Cal. '76 *ABBOTT, CHARLES W., Min. Engr. Pioche, Nev. ?08 *ABBOTT, JAMES W., Min. Engr: Ploche, Lincoln Co., Nev. '94 *AOTT, ROBERT R., Met. Engr., Peerless Motor Car Co., Cleveland, Ohio. '12 || ARAHAMS, ALEXANDER I., Student.. .67 E. 93rd St., New York, N. Y. '13

Jan 1, 1917

By E. B. Hunt

Paraffin deposition has been studied in the laboratory under conditions simulating deposition in well tubing. A theoretical analysis has been made of the cooling of the oil and the precipitation of paraffin from the oil as it flows up the well tubing and through surface flowlines. It is proposed that paraffin deposits are initiated by the precipitation of paraffin directly on or adjacent to the pipe wall and grow by diffusion of paraffin from solution to the deposit. This mechanism is consistent with laboratory and field observations, and has proved useful in the design and interpretation of laboratory paraffin-deposition tests. Tests have been made of the effect of plastic pipe coatings and chemical additives on paraffin deposition. INTRODUCTION Paraffin deposits which form in well tubing and surface flowlines interfere with production and must be removed. Over the years much progress has been made in developing and improving methods of removing these deposits after they form. Much less progress has been made in developing methods of preventing or inhibiting the formation of paraffin deposits. This is due, it is believed, to the lack of knowledge of the mechanism of paraffin deposition, the absence of satisfactory laboratory testing methods and the difficulties in evaluating the results of field tests of preventive treatments. The present investigation was undertaken to elucidate the mechanism of paraffin deposition and to develop suitable laboratory tests for studying the inhibition of paraffin deposition in well tubing and surface flowlines. Current theories on the mechanism of paraffin deposition have been evolved from field observations, from laboratory studies of various factors which might be involved in paraffin deposition, and from laboratory paraffin-deposition tests.1-9 Paraffin deposits have been formed in the laboratory by immersing a cold finger into a hot wax-oil solution and by flowing hot wax-oil solutions through cooled pipe or over cooled plates. These laboratory conditions differ in important features from field conditions, and the observed deposition behavior is not entirely field-like." Thus, there is reason to question the field applicability of the results of these tests. The present investigation was undertaken to determine how to perform and interpret laboratory paraffin-deposition tests to obtain information on the inhibition of deposition in the field. The paraffin problem in the broadest sense encompasses the formation of any predominantly organic deposit in well tubing, surface flowlines and other equipment in contact with crude oil or gas. The present investigation was limited to paraffin deposition involving the precipitation of paraffin wax from solution by cooling and its concentration in a deposit on a cooled surface. This probably excludes its applicability to those problems arising from asphaltic-base crudes, but not those arising from paraffin-or mixed-base crudes. This also excludes its applicability to emulsion and congealing oil problems which are often included as part of the paraffin problem. The phenomenon of cooling appears to be the controlling factor in paraffin deposition involving the precipitation of paraffin wax and its concentration in the deposit. Deposits of this type are usually found in the field only where cooling occurs. Early in this laboratory investigation, it was not found possible to form deposits under constant temperature conditions from a wax-oil slurry, either by steady flow through pipe or by gas-lift up a pipe. Thus, the investigation was limited to situations involving cooling. THEORY The relationships involved in establishing the temperature profiles in an oil stream as it flows up well tubing with a linear (geothermal) pipe-wall temperature distribution or through surface flowlines with essentially constant pipe-wall temperature are presented in the Appendix. The relationship between radial distance in the pipe and the rate of cooling of the oil is then combined with a relationship between cloud point and rate of cooling to develop the pattern of formation of a wax cloud in the oil. The following discussion of paraffin deposition under various laboratory and field conditions is based upon this development which is presented in the Appendix. PARAFFIN DEPOSITION IN SURFACE FLOWLINES The average temperature of the oil coming out of a well is somewhat higher than the ground temperature. Thus, the oil continues to cool on its trip through the surface flowline, and wax deposition can occur. The temperature distributions calculated from Eq. A-4 are given in Fig. 1. As can be seen, almost all the cooling occurs in the first 500 ft from the wellhead. In addition, the radial temperature gradient near the wall decreases rapidly with distance and becomes very small after a few hundred feet. Thus, growth of a paraffin deposit would be expected to decrease rapidly with distance from the wellhead and become negligible after a few hundred feet, since growth is dependent on concentration gradient. Wax precipitation and diffusion of wax to the already

By P. W. Bennett, E. M. Elkin

A new technique for the recovery of palladium and platinum and sludge from go12 electrolyte eliminates many of the drawbacks of the zinc-dust cementation process. In the electrolytic refining of gold by the Wohwill method, the electrolyte contains about 100 gpl gold as AuCl, and 100 gpl free hydrochloric acid. Any palladium and platinum contained in impure gold dissolve and accumulate in the electrolyte. When their concentration approaches that of gold, it becomes desirable to discard the electrolyte and to recover the gold and the palladium and platinum. As practiced at Canadian Copper Refiners until recently, discarded electrolyte was treated with sulfur dioxide to precipitate the gold. 2AuCl3 + 6H2O + 3SO2 —2Au + 6HC1 + 3H2SO4 The gold precipitate was filtered off, washed with water, and melted with scrap anodes. The wash water was added to the gold-free filtrate and treated with zinc dust to cement the palladium and platinum. PdCl2 + Zn — Pd + ZnCl2 PtCl4 + 2Zn—Pt + 2ZnCl2 The precipitate was separated and sold as Pd-Pt concentrate, and the barren filtrate and wash water were discarded. The receipts of palladium and platinum at this company were too small to warrant their refining. The process suffered from a number of disadvantages. Handling the gold-free solution was disagreeable, as it was laden with sulfur dioxide even after blowing with air overnight. Subsequent treatment with zinc dust was also troublesome. A large excess of zinc dust was required. Spray, acid mist, and vigorous evolution of hydrogen accompanied the reaction. The Pd-Pt precipitate was grossly contaminated with occluded unreacted zinc and with yellow granules of sulfur, thought to be formed by the reduction of sulfur dioxide and its derivatives. Repeated boiling of the precipitate with hydrochloric acid and washing with water decreased somewhat, but did not eliminate, the zinc. After drying overnight, the precipitate hardened to a clinkerlike mass that was difficult to grind. Grinding, handling, and packing created heavy dusting. Even weighing in an analytical balance generated dust, indicating that the powder was easily charged with static electricity. The total palladium and platinum content of the powder varied from 56 to 72 pct, with an average of 65 pct. The powder dissolved in aqua regia with difficulty, leaving a small amount of insoluble residue. However, the main drawback of the process was the strongly hygroscopic Pd-Pt product. The powder showed a marked though erratic increase in weight and a corresponding decrease in assay on exposure to air, even during the course of laboratory analysis. Such changes were the source of disagreement between Canadian Copper Refiners and the buyers of concentrate. The cause of the change in weight is believed to be hydrogen, liberated by the action of zinc dust on hydrochloric acid. Some of this hydrogen was adsorbed so strongly by the precipitate that it could not be driven off during the drying. On exposure to air it oxidized catalytically, forming water. Experiments soon showed that the entire process of treatment of discarded electrolyte then in use would have to be changed. A small quantity of apparatus was moved into the gold room, and experimentation was held to a minimum compatible with the development of a new process. PALLADIUM AND PLATINUM PRECIPITATION It was thought that zinc could be replaced with a reagent other than a hydrogen-evolving metal. Semiquantitative experiments showed that platinum and palladium could be precipitated completely from the gold-free solutions with such well-known reagents as sodium formate, formic acid, formaldehyde, and paraformaldehyde. Sodium formate was the preferred reagent, since the other three are volatile and somewhat toxic. The gold-free solutions used were those saturated with sulfur dioxide, partly freed of sulfur dioxide by aerating overnight, completely freed by boiling, as well as strongly and weakly acidic, neutral, and alkaline solutions. The reactions are complex and can be represented by these over-all equations: PdC1, + HCOONa — Pd + NaCl + HC1 + Co2 PtCl4 + 2HCOONa — Pt + 2NaCl + 2HC1 + 2CCX, Strongly acidic solutions required as much as five times the theoretical amount of sodium formate as did solutions neutralized to pH 4.5. Increasing the pH decreased the consumption of

Jan 1, 1965

By Frederic Carter

THERE have been many attempts to prove that platinum was known to the ancients, but since no traces of the metal have been found in the relics of early times, it must be concluded that it had not been known to them. As far as records go, it was actually first discovered in the 16th century in a Spanish mine on the Pinto River in South America; from which source it received its name of Platina del Pinto (little silver from the Pinto). It was more or less of a rarity and was a subject of interest to a few chemists only, until the year 1822 when the metal was first discovered in Russia. In 1819 there had been noticed in the washings of the gold sands of the southern part of the Ural Mountains, grains of a heavy white substance, but it was not until three years later that this substance was found to contain platinum. While at first the amounts of platinum brought from the Urals had been meager, prospecting soon disclosed rich deposits extending over a considerable area, and nuggets from 10 to 20. lb. were by no means rare. This discovery assured to chemists an ample supply of platinum for their crucibles, etc. The ore is now found in various parts of the world but the richest deposits are still found in the Ural Mountains. The platinum of commerce is obtained entirely from alluvial deposits at depths varying from 6 to 40 ft. The sand and gravel of former river beds are subjected to a series of screenings and washings to effect the separation of the ore. Actually, probably all gold-bearing gravel beds of the world contain platinum, and it is more than likely that large quantities of platinum ore have been thrown away with the black sand washings from gold placer deposits. This is especially true of the alluvial deposits of the Pacific Coast in California and Oregon. Platinum ore is usually found in the form of rounded or, flattened grains of "sand," and occasionally in irregular lumps of the size of peas. Large nuggets are very rare. The ore has a metallic luster and is distinguished by its steel gray color, but shows light gray streak when rubbed on a hard white surface; it has a high specific gravity, 16 to 19; is infusible in the hottest blast furnaces, and insoluble in any single acid. Platinum ore is a complex body consisting of the metal in combination with varying proportions of the other members of the platinum group; iridium,

Jan 1, 1928

By Frederick O?Neil

SCOPE OF THIS REPORT THE object of this paper is to describe the present status and possibilities of liquid oxygen as an explosive based upon the investigations, research and practical work of the Ingersoll-Rand Co., and of the Air Reduction Co., from early in 1922 to date. The following work was done. 1. A study of the history and physical theory of L. 0. X. as an explosive. (No attempt will be made in this paper to give the history or theory, as this has already been covered by the literature on the subject.) 2. An investigation of the use and the practice with L. 0. X. in the iron mines of Lorraine where L. 0. X. has its largest application in Europe. Although L. 0. X. is extensively employed in the; iron mines of Lorraine, many of the mines using it exclusively, and blasting with it a total of approximately three million tons of iron ore per year, the fact that the mining practice in Lorraine1 is to drill comparatively shallow holes and blast only a few holes at a time, renders the data obtained there of very little value in estimating the possibility of replacing dynamite with L. 0. X. in American mining methods. In fact, in the iron mines in Lorraine, L. 0. X. replaced black powder, or its equivalent. 3. Laboratory research work on properties of absorbent materials. 4. Work in the Bureau of Mines explosive laboratory at Pittsburgh, Pa., on the properties of L. 0. X. cartridges. 5. Practical work underground with L. 0. X. cartridges in the Witherbee-Sherman iron mines at Mineville, N. Y. 6. Practical work in the quarries of the Calcite Quarry Co., Myers-town, Pa. 7. Practical blasting in several quarries and open-pit mines.

Jan 2, 1926