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By C. R. Taylor, John Chipman

THE study of chemical reactions of liquid steel and basic open-hearth slag involves a complex slag system of at least eight important components, and often a number of others. In initiating an experimental program on the equilibrium relationship of slag and metal, it became evident that but little progress could be expected in the interpretation of the complex slags until an understanding had been gained of the simpler liquid systems composed of a limited number of slag constituents. The simplest system that in any way resembles open-hearth slag must contain lime, silica and iron oxide. Attempts to produce in an induction furnace slags containing only these constituents have met with serious limitations because of the solubility of refractories in the slag. Thus in acid-lined furnaces the slag is always saturated with silica and consequently contains between 48 and 63 per cent of this component. In basic-lined furnaces an undesired additional component, magnesia, is introduced to the extent of some 3 to 15 per cent, depending upon the acidity, sometimes with disastrous results to the furnace. Thus in a magnesia-lined furnace, Fetters and Chipman1 found it impossible to prepare slags in which the ratio (CaO + MgO)/SiO2 was less than that corresponding to the metasilicate (approximately 0.8: I). Between this composition and that of the true acid slags lies a field of composition about which very little is known and which cannot be explored by any ordinary means. This circumstance, as well as the desire to study the more basic slags in the absence of magnesia, calls for the development of a method by which slags may be brought into equilibrium with molten metal without coming in contact with refractory. Such a technic has been provided by the rotating induction furnace developed by Barrett, Holbrook and Wood.2 Three modifications of the rotating furnace were described by these authors. The first was essentially a rotating refractory cylinder containing the magnesia crucible, which was itself heated by a graphite crucible. In the second, only the magnesia crucible rotated, the cylindrical graphite heater being stationary. In the third, the coil and crucible revolved, and the metal was heated directly by induction. EXPERIMENTAL METHOD Furnace The furnace used in this investigation differed from previous designs and may be considered a fourth modification of the original rotating furnace. Its essential features are shown in Fig. I. The outer case A is a fire-clay flue liner for control of the atmosphere. The top B and base C are alberene stone. The coil supports D are of "Formica," a material formed from phe-

Jan 1, 1942

By Tell Ertl

THE Piceance Creek Basin in northwestern Colorado is believed to contain the richest large deposit of oil shale in North America. The major portion, about 1650 sq miles, is bounded by the White River on the north, the Grand Hogback, which runs from Meeker to Rifle, on the east, the Colorado River to the south, and the drainage basin of Salt and Douglas Creeks on the west. The Basin is a plateau 7000 to 9000 ft high, composed of 3000 ft of the Green River series of Eocene age and surrounded by a steep escarpment of 1000 to 3000 ft. From the escarpment the beds dip gently toward the center. Although oil shale is found in all members of the Green River series, the rich thick beds are found chiefly in the Parachute Creek member. This is normally capped by 100 to 200 ft of the Evacuation Creek, the youngest member of the Green River series. Actually the Piceance Creek Basin oil shale is not a shale, nor does it contain oil. It is magnesium marlstone holding solid organic matter capable of being broken down by heat into gases, some of which can be condensed into oil. The marlstone is resilient nonporous rock, difficult to sample by pick or hammer and moil. Many companies and individuals prospected the Colorado oil shale shortly after the first World War,' see Fig. 1, but because of the discovery of large quantities of petroleum in the late 1920's in Cali- fornia, Oklahoma, and East Texas, interest in oil shale development waned and did not revive until World War 11. In 1944 the writer, employed by the Bureau of Mines, prospected the high grade oil shale in numerous places along the southern outcrop of the Piceance Creek Basin. Several channel samples about 100 ft in length were cut, see Fig. 2. An eight-man crew needed a week to cut a satisfactory channel 80 ft long in the cliff face. The Phillips Petroleum Co., the Union Oil Co. of California and others also prospected the oil shale outcrop. In 1945 the Bureau of Mines initiated a core drilling program for the purpose of obtaining accurate samples from the Piceance Creek Basin. The U. S. Geological Survey set up a program for the geological study of the Basin that is still going on." Until the end of 1951 a total of 31 holes was drilled for core with diamond drills, and, in addition, cuttings through the oil shale have been obtained from 4 gas wells drilled by standard rotary oil well rigs. The Bureau of Mines drilled 12 of the holes, the Union Oil Company of California 8, the Standard Oil Company of California 6, the Sun Oil Company 3,

Jan 1, 1953

By Tell Ertl

THE Piceance Creek Basin in northwestern Colorado is believed to contain the richest large deposit of oil shale in North America. The major portion, about 1650 sq miles, is bounded by the White River on the north, the Grand Hogback, which runs from Meeker to Rifle, on the east, the Colorado River to the south, and the drainage basin of Salt and Douglas Creeks on the west. The Basin is a plateau 7000 to 9000 ft high, composed of 3000 ft of the Green River series of Eocene age and surrounded by a steep escarpment of 1000 to 3000 ft. From the escarpment the beds dip gently toward the center. Although oil shale is found in all members of the Green River series, the rich thick beds are found chiefly in the Parachute Creek member. This is normally capped by 100 to 200 ft of the Evacuation Creek, the youngest member of the Green River series. Actually the Piceance Creek Basin oil shale is not a shale, nor does it contain oil. It is magnesium marlstone holding solid organic matter capable of being broken down by heat into gases, some of which can be condensed into oil. The marlstone is resilient nonporous rock, difficult to sample by pick or hammer and moil. Many companies and individuals prospected the Colorado oil shale shortly after the first World War,' see Fig. 1, but because of the discovery of large quantities of petroleum in the late 1920's in Cali- fornia, Oklahoma, and East Texas, interest in oil shale development waned and did not revive until World War 11. In 1944 the writer, employed by the Bureau of Mines, prospected the high grade oil shale in numerous places along the southern outcrop of the Piceance Creek Basin. Several channel samples about 100 ft in length were cut, see Fig. 2. An eight-man crew needed a week to cut a satisfactory channel 80 ft long in the cliff face. The Phillips Petroleum Co., the Union Oil Co. of California and others also prospected the oil shale outcrop. In 1945 the Bureau of Mines initiated a core drilling program for the purpose of obtaining accurate samples from the Piceance Creek Basin. The U. S. Geological Survey set up a program for the geological study of the Basin that is still going on." Until the end of 1951 a total of 31 holes was drilled for core with diamond drills, and, in addition, cuttings through the oil shale have been obtained from 4 gas wells drilled by standard rotary oil well rigs. The Bureau of Mines drilled 12 of the holes, the Union Oil Company of California 8, the Standard Oil Company of California 6, the Sun Oil Company 3,

Jan 1, 1953

By A. Lawley, H. W. Schadler

TWINNING has long been recognized as a possible mode of deformation in crystalline solids and has been studied in a wide variety of crystals.&apos; Recently, deformation markings which have the topographical characteristics of twins have been seen in tungsten" and the body-centered cubic alloys of tungsten and molybdenum with rhenium.3-7 These markings have been identified as twins because: 1) they are visible after polishing and etching;2,3 2) their formation is accompanied by an audible click and a drop in load;4 and 3) the habit plane is {112}, the plane which has been identified as the twinning plane for several body-centered cubic metals.&apos; However, there has been no published evidence for the specific determination of the twinning direction in rhenium alloys of tungsten and molybdenum, because usually the deformation twins were not broad enough to be detected with a conventional X-ray beam. Consequently, [111] is inferred as the twinning direction since the latter must lie in a plane of symmetry perpendicular to the twinning plane (112). As Sims and Jaffee3 and Lawley and Maddin4 have shown, the addition of rhenium to molybdenum and tungsten increases the ductility of the alloy over that of the pure metal, but twinning is much more profuse in these alloys than in the pure elements, particularly at Mo-35 pct Re*and W-30 pct Re. Since twinning is often associated with brittle fracture in iron8 and the silicon-irons,9 direct experimental proof that the deformation markings in tungsten and molybdenum alloys of rhenium are twins seemed to be needed. Using the Laue back-reflection technique, the deformation markings in a Mo-35 pct Re alloy are shown to be deformation twins. The twins have a (112) habit plane and the twinning direction is <111>. The Mo-35 pct Re specimen used was taken from a 0.060-in. zone-refined single crystal deformed 6 pct in tension at 78°K. The Laue back-reflection technique, with a film to specimen distance of 2 cm, and white radiation from a copper target were used.

Jan 1, 1962

By A. U. Seybolt

RECENTLY, cases of coexisting ordered and disordered phase equilibria have been reported among face-centered cubic metals,1"3 but not on body-centered cubic systems.4 McQueen and Kuczynski5 showed a single line as the boundary between ordered solid solution of Fe3Al type and corresponding disordered solution in the Fe-A1 phase diagram based mainly on dilatometric and magnetic measurements. Such a single line would indicate a second or higher order transition. or an absence of coexisting order and disorder. The writer found previously a two-phase equilibrium region at 800°C consisting of ordered and disordered solid solutions of Fe3Si in a matrix of approximately 1-6 wt pct Si (Fe3Si is of 14.3 wt pct Si). A similar two-phase region of ordered and disordered Fe3Al solid solutions might be expected if the similarity between Fe3Si and Fe3Si structures hold true. In the present investigation, a wire of 22 at. pct Al, balance Fe and 0.0513 cm in diameter was subjected to electrical resistivity measurement in vacuum as a function of temperature between 300 and 800°C, see Fig. 1. There was excellent agreement between data taken on heating and on cooling: no hysteresis was observed. The Curie temperature was determined to be 640 °C which agrees with the finding by McQueen and Kuczynski.5 But in addition, there were two transitional points in the resistance-temperature plot at 510oC and 400 "C. The former is thought to be a connection with the transition from disordered state to a coexisting order and disordered equilibrium state; while the latter, from such coexisting state to ordered state. Fig. 2 shows a phase diagram where the suggested two-phase region lies between dotted lines. The solid lines are those of McQueen and Kuczynski.5 Since these authors found only a single-phase boundary between ordered and disordered Fe3 Al, it would seem likely that the dilatometric method used by these authors was not sufficiently sensitive to resolve the ordering reaction into the two-phase boundaries. In addition, their phase diagram conflicts with the statement they make on P. 1 of their paper: "The sharpness of the peaks indicates that ordering to Fe3A1 is a first order reaction." The suggestion of coexisting order plus disorder in Fe3A1 must be considered tentative until confirmed by high-temperature X-ray examination. If

Jan 1, 1961

By Raymond C. Boettner

The present work had for its purpose: 1) the identification of crack nucleation sites in AISI 4340, quenched to martensite and tempered over a range of &apos;temperatures; and 2) the comparison of fatigue processes in AISI 4340 with processes observed previously in pure metals From constant def1ection-bending fatigue tests, martensite boundaries were identified as the favored crack nucleation sites in quenched and tempered AISI 4340. It, also, was concluded that the fatigue processes operating- in this lous-alloy steel were similar to Processes observed in pure tnetals. ALTHOUGH much engineering data has been accumulated on the fatigue properties of quenched and tempered martensitic steels,&apos; fatigue as a process is not as well understood in martensite as it is in pure metals.&apos; Important features of the fatigue process, such as the identity of the nucleation sites, have not been determined in the commercially important high-strength low-alloy structural steels. The present work had for its purpose: 1) the identification of crack nucleation sites in a low-alloy steel, i.e., AISI 4340, which had been quenched to martensite and tempered over a range of temperatures; and 2) the comparison of fatigue processes in the AISI 4340 with processes observed previously in pure metals. This comparison of the fatigue processes in the different tempers was restricted to the high-strain low-cycle part of the S-N curve. Under these test conditions, previous work on a number of metals has shown that a large number of cracks are nucleated in less than 30 pct of the fatigue life.3 Furthermore, crack nucleation sites are not restricted to inclusions but are also associated with intrinsic structural characteristics of the metal. MATERIAL A 20-lb ingot of vacuum-melted AISI 4340 (for composition see Table I) was hot-rolled to 1-in.-diam rod and then cold-rolled to a 1-in.-wide strip, 0.08 in. thick. Fatigue specimens, see insert of Fig. 1, were machined from the strip with the long dimension parallel to the rolling direction. m this orientation, the stringers of 1 to 2 p inclusions present in the sheet lay parallel to the stress axis in the specimens. The specimens were austenitited at 2050°F in order to obtain a large prior austenite grain size, i.e., 2 mm, which facilitated the subsequent identification of the prior austenite boundaries. A helium atmosphere was used to minimize decarburization. After austenitiza-tion at 2050°F, the specimens were transferred to a 1450°F furnace so that specimen distortion was held to a minimum in the subsequent oil quench. Previous work4 indicated that refrigeration in liquid nitrogen prior to tempering reduced the percentage of retained austenite in the quenched specimens to less than 5 pct. Tempering was carried out in air over the temperature interval of 200°to 800°F to produce a range of mechanical properties, Table I. The preparation of the fatigue specimen was completed by grinding about 0.005 in. from each surface and electropolishing in a chrome trioxide-acetic acid solution for 30 min. Examination of etched cross sections of specimens prepared in this fashion showed the foregoing specimen preparation to be adequate for the removal of the decarburized layer present after the heat treatment. Transmission electron microscopy showed that the as-quenched microstructure of this alloy consisted of a mixture of martensite plates containing either a high density of dislocations or microtwins. Previous work5&apos;6 indicated that in the course of oil quenching autotem-pering resulted in the formation of E carbide on the martensite and microtwin boundaries. Tempering for 2 hr at temperatures up to about 400°F resulted in further precipitation of the E carbide. Finally, at about 400°F, cementite began to replace the E carbide on the martensite and microtwin boundaries in addition to forming a Widmanstatten structure within the plate matrix. EXPERIMENTAL S-N curves were obtained using electropolished specimens cycled at 1800 cpm as cantilever beams in fully reversed bending at selected constant deflections. The deflections were translated into surface strains by means of a calibration curve obtained through the use of strain gages. An argon atmosphere was used to minimize environmental effects. To investigate the development of fatigue slip bands, the specimens of the different tempers were unidirec-tionally bent to a surface strain of 0.005 to 0.007, photographed to record the location and appearance of slip bands so introduced, and then cycled to failure

Jan 1, 1968

By Frank W. Clinard, Oleg D. Sherby

The effect of multiple an transformations on diffusion in a dilute iron alloy was studied. Inter-penetration between iron and an Fe-Co alloy was evaluated, under thermal-cycling conditions chosen so as to transform only the iron-rich side of the diffusion couple. It is shown that a small but consistent diffusion enhancement by a factor of two results when data from the transforming side of thermally cycled specimens are compared with predicted inter diffusion coefficients based on isothermal data. No enhancement is found when data from the mntransforming side of such couples are compared with predicted diffusivities. It is suggested that short-circuiting by moving pain boundaries is the most likely mechanism contributing to the observed diffusion enhancement from multiple phase transJormations in iron. Transformation-induced Point defects, dislocation-pifie short-circuiting, and point defects generated by dislocation motion are less effective in contributing to enhanced diffusion under the experimental conditions utilized. SO far as is known, no studies have been made of the effect of allotropic transformation on diffusion. previous to this investigation. Studies have been made, however, of the influence of transformation on the diffusion-controlled processes of spheroidization and sintering. Cullen1 has described a method of accelerating spheroidization in an AISI 1030 steel. Partial transformation between a and ? phases was uti-

Jan 1, 1965

By Albert Zima

ACCORDING to recently published statistics, it is predicted that as much oil must be produced during the next 16 years as has been produced during the past 75, in order to satisfy the high rate of consumption of petroleum products. During 1934, over 17,000 oil wells were completed in the United States, and it is expected that over 20,000 additional wells will be drilled during the current year. Were it not for the remarkable progress made during recent years in the improvement of drilling technique and in the development of equipment used in the production phase of the oil industry, it is doubtful whether sufficient oil could be produced to meet present requirements. A few years ago, wells seldom were deeper than 3500 to 4000 ft., owing to the limitations of the drilling methods and equipment employed. Today, however, through the application of scientific drilling methods and the adaptation of modern equipment and improved materials, many wells range from 6000 to 8000 ft. in depth, and a few recent completions exceed 10,000 feet.

Jan 1, 1935

By A. M. Tweedy, Felix A. Vogel

Since the publication of Prof. J. W. Richards&apos;s paper on The Schumacher Briquetting Process,&apos; this process has been in operation on a practical scale in two plants in the United States, and a few notes on the results obtained may be of interest. An experimental plant, consisting of a toggle press and a hydraulic press, was installed at Johnstown, Pa., together with the necessary bins and other equipment, and an attempt was made to briquette a mixture of Mahoning fines and blast-furnace flue dust, in a ratio of 7 parts of ore to 3 parts of dust. The results were unsatisfactory, in that the briquettes made were not hard enough to stand the severe handling to which they were subjected in the various transferences necessary between the press and the furnace. The trouble was due to several causes: First, the mechanical arrangement of the plant, which did not lend itself to a proper hardening and loading of the briquettes into the cars. Second, the irrrgular composition of the flue dust, as to both its lime and its fine coke contents. Third, the variability of the moisture content of the ore, and its viscosity when wet. Fourth, the ratio of fine ore to flue dust; that is, it was attempted to bind in too large a quantity of fine ore for the small amount of flue dust used. The first trouble could be overcome, and has been improved upon in the plant as it stands to-day. The second trouble was important, because of the small amount of dust used as a binder, and might have been easily removed by mixing the flue dust of the different furnaces, which, however, was never done. The third difficulty was more serious, but could have been partly solved, had it been possible to meet this along with the fourth difficulty, by decreasing the percentage of ore in the briquettes. It was proposed to do this, but it seems that the problem at the works in question is, primarily, to prepare Mahoning fines for reduction in the blast furnace, and only secondarily to use up the flue dust, and a solution along this line did not seem to be interesting.

Jan 1, 1914

By Nathaniel Herz

The formula very frequently used for computing the economical size of pipe to transmit compressed air is that of D&apos;Arey, as follows: D = cV w1l Where, D = the volume of compressed air delivered in cubic feet per minute, at the final pressure. c = an experimental coefficient determined for the various sizes of pipe, d = the diameter of the pipe in inches. 1 = the length of the pipe in feet. p, = the initial gauge-pressure in pounds per square inch, p2 = the final gauge-preesure in pounds per square inch. w1 = the density of the air, or the weight in pounds per cubic foot at the initial pressure, p1. The most common case is that in which the given quantities are: the quantity of air required, the length of the pipe, and the initial pressure. The method of solution is to assume a pressure-loss and to compute the remaining factor, cd5, thus giving the size of pipe corresponding to the assumed loss of pressure. It is always desirable to try two or more pressure-drops, in order to find the combination that is most satisfactory, since often a small change in the size of pipe will reduce or increase the loss of pressure several pounds. An alternative method is to assume a size of pipe and calculate the corresponding pressure-drop. Each method involves a series of tedious calculations to arrive at the most economical solution, and also requires the use of tables giving the constant, c, the density of the air, w1, and often, for convenience, a table giving the values of the expressions p1-p2 and c J I hare constructed a graphic chart, Fig. 1, for the solution of

Jan 1, 1913

By M. N. Brodie, John Chapman

INTRODUCTION - DEFINITION & HISTORICAL PERSPECTIVE While this symposium is concerned with comminution which, by definition, relates to all stages of size reduction of an ore body to a form suitable for mineral separation, the electrical drive aspect of the grinding section will receive most attention in contrast to the crushing, screening and materials handling elements of the process. The reason for this is that today&apos;s large mills, thirty feet diameter and upwards, present mechanical and electrical problems which require a degree of sophistication in their solution not previously required. The ability to satisfy these demands, so far as electrical technology is concerned, largely results from the development of semi-conductor devices. These can now handle typical electrical distribution power levels within remarkably s m all volumes and with high efficiency when compared with the motor-generator sets, mercury arc rectifiers, rotating amplifiers, magnetic amplifiers and vacuum tubes which were commonly used to provide speed and torque controls as recently as the early nineteen-sixties. The hardware available to the electrical engineer has changed dramatically whereby even the simplest control system formerly using hard-wired relays is now superseded by the program m able logic controller with its computer-like memory containing the sequence of operation, in other words, the software. Reverting now to the mineral process itself, it is assumed that the ore body has been mined using explosives and is delivered to the concentrating plant in its &apos;run of mine&apos; form. The problem becomes one of reducing the material to a size which will permit an acceptable recovery of the mineral with the most economical use of energy. The size of &apos;run of mine&apos; material will range from about minus five feet for high tonnage open pit operations to minus two feet for the smaller underground mine. The final reduction in size may range from minus ten mesh to minus two hundred mesh (exceptionally as fine as minus six hundred mesh) depending upon the concentration method and dissemination of the mineral values within the ore. There is no single circuit that satisfies all applications, but the pattern of metallurgical equipment use shown in Table 1 appears discernable from current practice, in general terms.

Jan 1, 1982

By K. C. Ten Brink, Allen D. Garrison

A rrevious paper1 reviewed some of the properties of clays and shales and presented some data on the nature of the gelling phenomenon. It included a brief discussion of origin of clays and shales, their composition, structure, retention of water, ionization, base exchange, and the nature of the gelling of water suspensions. Other publications of the Institute2-8 have discussed the properties of clays and their relations to drilling-fluid behavior and control. It is the purpose of this article to present some new data obtained and arranged in a different manner and making possible a better understanding of the chemical reactions involved in the control of drilling-fluid characteristics during the normal drilling operations. Experimental Procedure The difficulties involved in the measurements of the flow characteristics of plastic fluids are too familiar to recite. The possible applications of some of the well-known instruments to this problem have been adequately discussed by Hobson9 and he has given an excellent bibliography. Although there are many viscosimeters of varied design, none of them appear to fulfill the most obvious demands of accuracy in the measurement of clay or shale suspensions. Since the fluid characteristics are dependent on the rate of flow of the fluid, and the viscosity usually falls off very rapidly as the rate is increased, it is clear that the first requirement is that the instrument shall be capable of a wide variety of speeds. The viscosity of the fluid at any fixed and constant rate of flow is also a function of time, so that the second demand is that the instrument shall be capable of a constant and continuous motion for a prolonged period of time.

Jan 1, 1940

By K. C. Ten Brink, Allen D. Garrison

A rrevious paper1 reviewed some of the properties of clays and shales and presented some data on the nature of the gelling phenomenon. It included a brief discussion of origin of clays and shales, their composition, structure, retention of water, ionization, base exchange, and the nature of the gelling of water suspensions. Other publications of the Institute2-8 have discussed the properties of clays and their relations to drilling-fluid behavior and control. It is the purpose of this article to present some new data obtained and arranged in a different manner and making possible a better understanding of the chemical reactions involved in the control of drilling-fluid characteristics during the normal drilling operations. Experimental Procedure The difficulties involved in the measurements of the flow characteristics of plastic fluids are too familiar to recite. The possible applications of some of the well-known instruments to this problem have been adequately discussed by Hobson9 and he has given an excellent bibliography. Although there are many viscosimeters of varied design, none of them appear to fulfill the most obvious demands of accuracy in the measurement of clay or shale suspensions. Since the fluid characteristics are dependent on the rate of flow of the fluid, and the viscosity usually falls off very rapidly as the rate is increased, it is clear that the first requirement is that the instrument shall be capable of a wide variety of speeds. The viscosity of the fluid at any fixed and constant rate of flow is also a function of time, so that the second demand is that the instrument shall be capable of a constant and continuous motion for a prolonged period of time.

Jan 1, 1940

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&apos; &apos; 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 Robert Pack

INTRODUCTION SOONER or later in the development of any natural resource it becomes highly desirable to know the quantity of this resource in the country as a whole, as well as of the part that is being developed, for the general course and. conduct of the development work must be governed to some extent by the total supply available. An accurate estimate of the quantity of any natural resource is difficult to make; yet if one is diligent enough one can obtain a pretty accurate idea of the quantity of marketable timber, the acreage of tillable land, or the horsepower that may be developed from the streams, for these are things that may be measured. But any attempt to estimate the quantity of some mineral in the ground appears to enter the realm of imagination and it seems that the estimate can be nothing more than a blind guess. It may appear to be especially futile to attempt to determine the quantity of oil and gas that is available in the ground, for these minerals are so vagrant that even if the quantity now available should be known quite exactly, the quantity that will eventually be obtained may be much less, for certain losses in the extraction of both oil and gas are unavoidable, and just what these losses will be cannot be predicted. Though necessarily inaccurate, estimates of such mineral reserves are, however, of distinct value, for they summarize the existing knowledge of the deposits of the mineral and thus enable those who are interested in some industry that depends in one way or another on this mineral to formulate a rational commercial policy. Some time ago, when the price of gasoline suddenly rose in a rather spectacular manner, the writer was one of the U. S. Geological Survey geologists called upon to help to estimate the quantity of oil that could be obtained in the United States, for the fear had become widespread that perhaps the rate of increase in the price of gasoline was a measure of the rate of depletion of the supply of petroleum. It thus became his

Jan 8, 1917

By G. Thodos, R. B. Grieves

A method has been developed for the accurate calculation of the cricondentberm and cricondenbar temperatures of multicomponent hydrocarbon mixtures of known composition. The mixtures may contain any number of components including paraffins and isoparaffins, olefins, acetylenes, naphthenes and aromatics. This approach is based upon the mole fraction of the low-boiling component in the mixture and graphically presents the ratios of the cricondentherm and cricondenbar temperatures to the pseudocritical temperature as {unctions of a boiling-point parameter. The only requirements are the critical temperature, normal boiling point and the approximate vapor pressure behavior of each component. For mixtures of more than two constituents a stepwise calculation procedure is necessary where the pseudocritical temperature is based upon the critical temperature of the pure low-boiling component and upon the actual cricondentherm or cricondenbar temperature of the mixture of all the remaining higher-boiling components. From an analysis of 22 binary systems (123 compositionsl, the average deviation of calculated cricondentherm temperatures from reported values is 0.87 per cent, based on degrees Rankine; and for 10 multicomponent mixtures containing from three to six components, the average deviation is 0.98 per cent. From an analysis of 18 binary systems (104 compositions) the average deviation of calculated cricondenbar temperatures from reported values is 0. 79 per cent; and for 15 multicomponent mixtures, 1.47 per cent. Equations, derived from the graphical relationships, are presented which enable rapid calculations for both binary and multicomponent systems. INTRODUCTION With the increasing tendency towards the use of high pressure processes, the need for an accurate method of calculation of the properties of a multicomponent hydrocarbon mixture in the critical region is becoming more essential. Critical region phase relations are also significant in gas condensate reservoirs, for which a knowledge of the fluid phase boundaries and regions of retrograde condensation make it possible to evaluate optimum operating conditions. The possibility of liquefaction in the underground structure may be established, and information on the feasibility of the use of repressurizing may be determined. A typical phase diagram for a multicomponent hydrocarbon mixture is presented as Fig. 1. This figure also shows the regions of retrograde behavior encountered by following lines AB and AC. If accurate methods of calculating the temperatures and pressures at the critical, cricondentherm (maximum temperature) and cricondenbar (maximum pressure) points of multicomponent hydrocarbon mixtures of known composition were available, it would be possible to estimate closely the entire phase diagram of any mixture. Several methods have been presented in the literature for the estimation of the critical temperatures and pressures of multicomponent mixtures containing all types of hydrocarbons and including the fixed gases.4-8,21 Considering the cricondentherm and cricondenbar points, the work is more limited. Etter and Kay5 have developed rather complex equations for

By H. P. Stüwe

HE recent papers of Aust and Rutter112 have again brought to mind the importance of certain "special" orientation relationships between the lattices of two fcc crystals on the mobility of the grain boundary separating them. No theoretical treatment of this problem has been offered till now. The only principle published so far that has given an indication why certain orientation relationships should be "special" is the counting of "coincidence sites" according to the suggestions by Kronberg and Wilson.3 The "coincidence plots" published by these authors show, for instance, that two fcc lattices rotated by 38 deg around a common (111)-axis have 1/7 of their lattice sites in common. Such an orientation relationship is also characteristic for high boundary mobility. The accuracy of the orientation relationship needed for high mobility is not too rigid. Deviations up to 10 deg from the ideal orientation seem to be tolerable as can be gathered from the experimental data.&apos;j4 The auestion arises, then. how the density of coincidence sites will be affected by a deviatioi from mathematical accuracy. This can be checked by a simple model. Two sieves are prepared, the arrangement of the holes corresponding to lattice sites on a (111)-plane in a fcc crystal. They are placed upon each other, Fig. 1. One is kept fixed, the other is rotated around an axis pushed through one hole in common to both. The light falling through holes of both sieves is then a measure for the density of coincidence sites. If the diameter of the holes is very small, light intensity is contributed only by holes the centers of which coincide "exactly." If the diameter of the holes is rather large, some intensity will be contributed by

Jan 1, 1962

By S. P. Holt

The chief use of scrapers at this mine has been on lead ore of milling grade, clean and dry, in stulled stopes, 50-100 ft. long, 5-12 ft. high, and pitching 20-30°. Scrapers have also been used to fill these stopes with waste. The first scraper used (Fig. 1) is modified from a Cleveland-Cliffs design, being only 30 in. wide. It is light, weighing but 95 lb., handles well, and-digs itself in; but it spills part of its load on a long haul. It could be improved by lengthening the side plates, but because of the double bent angle irons, it is difficult to make at mine shops and has been discarded. Fig. 2 shows where the light angle irons have failed, spoiling

Jan 1, 1923

By S. P. Holt

The chief use of scrapers at this mine has been on lead ore of milling grade, clean and dry, in stulled stopes, 50-100 ft. long, 5-12 ft. high, and pitching 20-30°. Scrapers have also been used to fill these stopes with waste. The first scraper used (Fig. 1) is modified from a Cleveland-Cliffs design, being only 30 in. wide. It is light, weighing but 95 lb., handles well, and-digs itself in; but it spills part of its load on a long haul. It could be improved by lengthening the side plates, but because of the double bent angle irons, it is difficult to make at mine shops and has been discarded. Fig. 2 shows where the light angle irons have failed, spoiling

Jan 1, 1923

By Ralph Sweetser

AT the joint session of Blast Furnace and Open Hearth Committees, April 7, 1937, at Birmingham, the subject of the quality of basic open-hearth pig iron was so well presented and discussed from so many different viewpoints that it was the general opinion that progress had been made and that such meetings were conducive to the advancement of the art of making pig iron of the right quality for the open-hearth man to produce the most satisfactory quality of steel. It was agreed that there is a decided differentiation between the chemical analysis of pig iron and the "quality" of pig iron. Paul J. McKim said that open-hearth furnace operators frequently make refer-ence to certain types of iron as "bad iron," "dirty iron," "cold metal,&apos; etc., claiming that when using these irons, although they are within specified chemical analysis, it is impossible to produce quality steel. Mr. McKim gave a list of the suggested causes of those "certain types" of bad irons that have a thoroughly respectable analysis but a thoroughly disreputable character. Another open-hearth man, P. A. Maclsaac, of Nova Scotia, said that: The effects of iron flint is below standard in analysis or in that mysterious property called quality, are well known to all open-hearth operators. It has been shown that iron of this type results in the production of steels on which the rejections of finished product, run high. What is to be done about it? I would say that the burden of producing high-quality iron should be placed squarely on the shoulders of the blast-furnace man, even as that of making good steel is shouldered by the open-hearth luau. It is the purpose of this paper to bring out into the open this &apos;mysteri-ous property called quality"; that is, in those "certain types" of basic pig iron that make it impossible to produce quality steels; and at the same time to point the way for the blast-furnace man to be able to shoulder the burden that Mr. MacIsaac and all other open-hearth men and foundry-men have placed upon him.

Jan 1, 1938