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By William B. Potter

It is a time-honored custom in this, as in other kindred bodies, for the retiring President on giving place to his successor, after a year of official duties which have been the means of directing his attention in a more than usual degree to the work and interests of the Association, to report the results of his observations from this outlook, and the thoughts that may be suggested by the view. In looking out over the many fields of activity within the range of this Institute, the attention may be arrested by special features marking recent progress and development, or such as by their meager outline or lack of important detail stand in less pleasing contrast, or. even form unsightly objects in the view. It may be that the special field and particular work in which one is engaged will, when observed from the more distant standpoint, or in the light of the whole outlook of the profession, assume a different aspect or develop features of new interest and importance. In this way some special object may suggest to the observer a, fitting theme for the occasion. To others, again, an outline of the whole view may seem a more useful subject for study and review. All fields are examined and the wide horizon of the whole profession scanned to note and report whatever is new in knowledge and practice—the new permanent bench-marks that appear near the horizon designating ground definitely located; the stakes which mark reconnoissance into new territory, and even the prominent objects that faintly appear through the mist of the distant atmosphere, and which may serve later on as points of attachment for the advancing lines of survey into the unknown. And besides these, there is the progress of the work in older and nearer fields—what has been attempted, what accomplished,

Jan 1, 1889

By T. O. Anderson, E. J. Stahl

Tests to increase knowledge concerning the process of hydraulic fracturing have been performed on three wells in the Allegheny field in western New York. The fracture orientation and its physical appearance at the well-bore was determined by impression packers run at appropriate times throughout the program. Fract~tre azi171uth and its dimensions thus determined were compared to the rock properties and treatment conditions. Logs to provide data concerning rock properties and to improve identification of vertical fractures were run before each step of the fracture treatment. Pressure osc~illu~iot~s were studied after each phase of tile treatments surface pressures during treatment. These measurements show that subsurface pressures exhibit many of the same characteristics as surface pressures during treatment of a well; however, transient pressures are dampened and deelayed in time at the bottom of the well when COmpared with surface pressures. Data obtained from this study provides a means to help locale and determine orientation of vertical fractures made in the open wellbore. Although these rests were performed in only one area, much of the information gained may be applied to fracturing programs in orher areas. INTRODUCTION In this study, various tests were made to provide data to better understand formation fracturing in situ. The reservoir studied is the Richburg oil sand which is a part of a series of predominantly grey sandstones and shales with occasional brown sandstone layers, known as the Caneadea unit of the Canadaway group of Upper Devonian age. Average physical characteristics of 12 cored wells in this area are 13-ft thick gross sand formation, 12-ft thick net sand. 1.7 md permeability, 11 percent porosity, 44 percent oil saturation (before secondary recovery) and 16 percent water saturation (before secondary recovery). This particular area of the Allegheny oil field was originally drilled prior to 1890. The first waterflood secondary recovery attempt was made in 1929. The present sustained waterflood development began in 1951 and is being carried out on a 4.5 to 5-acre spacing. Objectives of these tests were to (I) study fracture azimuth and dimension in relation to rock properties and treating conditions, (2) improve fracture identification techniques, (3) compare surface and subsurface pressure during all phases of treatment and (4) compare the periods of the fluid column oscillations occurring after each phase of treatment. Although the areas of investigation listed appear divergent in purpose, the program was designed primarily to increase knowledge of down-hole conditions leading to rock failure and extension of the fracture thus created. TEST PROCEDURES Wells upon which tests were conducted are designated as Wells 1 through 3. Well 2 was located 440 ft north of Well 1, and Well 3 was located approximately 880 ft west of Well 1. Wells 1 and 2 were completed with cable tools, while the producing interval of Well 3 was rotary cored using fresh water as the drilling fluid to obtain oriented cores. Tests were divided into separate phases on each well as the fracturing program progressed and consisted of measurements performed prior to treatment, during and after the formation breakdown operation. during fracture treatment and after treatment. To verify location and azimuth of the fracture created, and to obtain an impression of wellbore irregularities, a packer was used (Fig. 1). This packer was lowered on tubing into the wellbore opposite the interval under study and inflated in stages to allow the impression material to conform to the wall of the wellbore. A magnetic compass was attached to the tool for orientation reference. Impressions made prior to treatment showed no existing fractures in the wells under study. Impressions made after both formation breakdown and treatment pro-

By J.B. Pullen

The United Verde mine is in the north central part of Arizona, on the northeasterly slope of the Black Hills, near the town of Jerome. Ore was first discovered in the district about 1875, and the first mining claims were located by M. A. Ruff-ner and associates in 1877. In 1888 the late Scnator William A. Clark secured control of the property and under his ownership it developed into one of the country's most important copper producers. The property was sold to the Phelps Dodge Corporation in 1935, and since then has been under this Corporation's management. Except for shutdowns caused by general world-market conditions, production has been continuous from 1890 to date. Geology The mineralized zone ranges in area from approximately 12 acres to less than 5 acres. All mineralization occurs in the pre--Cam-brian intrusives. The first intrusion, according to geologic records, was the quartz porphyry, which later was intruded by augite diorite. Following the diorite intrusion through a series of intrusions of lesser magnitude, a pipelike mass of massive sulphide, quartz and rock was formed. The diorite forms the hanging wall of this mass, and the porphyry the footwall. Between the footwall and the sulphide a band of chlorite schist was formed, probably owing to metamorphic conditions. Commercial ore occurs along the contact of the schist and sulphide extending into the sulphide, sometimes entirely through the schist, and fingering out into the porphyry. The ore deposit was formed by replacement similar to deposits formed in limestone areas. Faulting and deformation occurred in pre-Cambrian times and again in the Tertiary period, removing approximately 2000 ft. from the top of the main United Verde ore body, forming the United Verde Extension ore body, the only other major ore body in the district. Major development work has shown that the sulphide mass extends to the 3300-it. level, and diamond drilling below this level has indicated that the mass might extend below the 3700-ft. level, but in a diminished quantity. While many copper minerals exist in the mine, the chief commercial mineral is chalcopyrite. Aplan and vertical section of the mineralized zone showing the principal geological eatures is shown in Figs. I and 2. General Description and Physical Condition or Mine After over 50 years of active production, ore still exists on almost every level of the mine. This condition is due to many causes —-mine fires, which broke out as early as 1894, caused the abandonment of certain areas; subsidence and ground movements retarded the cleaning up of others. Furthermore, in the early days there was such an abundance of ore that when mining became dificult it was a simple matter to replace the production by going to a deeper level. Several attempts were made to recover the ore in the fire zone, both by glory-holing

Jan 1, 1943

By J. B. Pullen

The United Verde mine is in the north central part of Arizona, on the northeasterly slope of the Black Hills, near the town of Jerome. Ore was first discovered in the district about 1875, and the first mining claims were located by M. A. Ruff-ner and associates in 1877. In 1888 the late Scnator William A. Clark secured control of the property and under his ownership it developed into one of the country's most important copper producers. The property was sold to the Phelps Dodge Corporation in 1935, and since then has been under this Corporation's management. Except for shutdowns caused by general world-market conditions, production has been continuous from 1890 to date. Geology The mineralized zone ranges in area from approximately 12 acres to less than 5 acres. All mineralization occurs in the pre--Cam-brian intrusives. The first intrusion, according to geologic records, was the quartz porphyry, which later was intruded by augite diorite. Following the diorite intrusion through a series of intrusions of lesser magnitude, a pipelike mass of massive sulphide, quartz and rock was formed. The diorite forms the hanging wall of this mass, and the porphyry the footwall. Between the footwall and the sulphide a band of chlorite schist was formed, probably owing to metamorphic conditions. Commercial ore occurs along the contact of the schist and sulphide extending into the sulphide, sometimes entirely through the schist, and fingering out into the porphyry. The ore deposit was formed by replacement similar to deposits formed in limestone areas. Faulting and deformation occurred in pre-Cambrian times and again in the Tertiary period, removing approximately 2000 ft. from the top of the main United Verde ore body, forming the United Verde Extension ore body, the only other major ore body in the district. Major development work has shown that the sulphide mass extends to the 3300-it. level, and diamond drilling below this level has indicated that the mass might extend below the 3700-ft. level, but in a diminished quantity. While many copper minerals exist in the mine, the chief commercial mineral is chalcopyrite. Aplan and vertical section of the mineralized zone showing the principal geological eatures is shown in Figs. I and 2. General Description and Physical Condition or Mine After over 50 years of active production, ore still exists on almost every level of the mine. This condition is due to many causes —-mine fires, which broke out as early as 1894, caused the abandonment of certain areas; subsidence and ground movements retarded the cleaning up of others. Furthermore, in the early days there was such an abundance of ore that when mining became dificult it was a simple matter to replace the production by going to a deeper level. Several attempts were made to recover the ore in the fire zone, both by glory-holing

Jan 1, 1943

By S. W. Zanolli

The history of labor relations in the coal industry of the United States is a study of its collective bargaining. This study of collective bargaining is largely the history of the United Mine Workers of America and its contractual relations with the various coal mining employers who have produced this country's coal over the years under a free enterprise system. There have been other unions in the picture from time to time and some coal miners have mined coal without representation by any union. Even today some 25% of the nation's coal is produced outside of the collective bargaining relationship with the UMWA. However, more than 100,000 coal mine wage employees - well over 75% of the total in the industry - are covered by labor agreements negotiated for them by the UMWA. Practically all of these work in bituminous mines.

Jan 12, 1972

By Stephen Taber

A vein may be defined as an aggregation of mineral matter, more or less tabular or lenticular in form, which was deposited from solution and is of later origin than the inclosing rock. This definition differs from the one found in many text-books in that no assumption is made as to the origin of the space occupied by the vein or the manner in which the mineral matter was deposited. In the present paper the writer purposes to discuss the mechanics of vein formation, and does not wish to begin by begging the question. The origin of ore deposits has been diligently investigated in recent years, but, while much has been written concerning the chemistry of the process, the physical side of the question has received less attention. The source of the ore minerals; the chemical composition of ore-bearing solutions; the relative importance of magmatic and meteoric waters as agents of concentration; and the causes of mineral precipitation have all been discussed at length. On the other hand, little has been written concerning the mechanics of vein formation, and the theories given in text-books today are essentially the same as those developed by the early Cornish and Saxon miners. Early investigators often regarded both veins and dikes as igneous in origin, but today the theory that vein minerals have been deposited from solutions, either liquid or gaseous, is firmly established. The latter view is supported by the fact that many vein-forming minerals are not found in unaltered igneous rocks; by evidence obtained in the laboratory regarding the solubility of minerals; by the presence of many ore minerals in hot-spring waters; by the occurrence of some veins in regions consisting exclusively of unaltered sedimentary rocks; by evidence as to the temperature at which some minerals are formed; and by the absence of mineral segregation due to difference in specific gravity. There is still, however, much difference of opinion as to whether certain tabular-shaped masses should be classed as veins or as dikes. Some of the earlier investigators have also advocated the theory that veins are contemporaneous in origin with the inclosing rock, while others have believed the vein minerals to represent a recrystallization or transforma-

Jan 1, 1920

By Hobart M. Kraner, E. B. Snyder

THIS paper shows that volume stability, low porosity and decreased pyroplasticity are desirable for blast-furnace linings, particularly for the hearth. It shows further that a hot load test is a valuable means of testing the fusion or softening behavior of a refractory at operating temperatures. The effect of carbon monoxide on commercial blast-furnace refractories in their as-received condition and after refiring is reported, showing that many commercial blast-furnace refractories disintegrate badly but that refiring decreases the effect and certain special refractories are now available which are almost free of the tendency. FACTORS AFFECTING CHOICE OF REFRACTORIES If one were to depend entirely upon experience or trial in the selection of clay refractories, the solution of a problem would be a slow process. Furnace campaigns are so long and attended by so many variables that it is difficult to draw fine distinctions within a reasonable period of time in regard to the quality of refractories used. It could be said, of course, that if service results do not yield the proper information for intelligent choice, there is no difference in the quality of brick being considered, but this is not necessarily true. Conventional ceramic tests are designed to give the ceramic engineer information as to the refractoriness and firing temperature, which he in turn interprets in terms of volume stability, ability to withstand load at high temperature (pyroplasticity), permeability, chemical stability and resistance to the action of slag. In most refractory applications several of these factors are involved. In a particular instance, one requirement may be predominant, while in others some other factors may be of primary importance. In this country, clay refractories are generally made from mixtures of plastic and flint fire clays. The process of firing a clay refractory is one of slowly melting the constituents, and during this operation its porosity is gradually reduced. The process is arrested, of course, in its incipient stages and the progress is determined by measuring slight changes in. porosity, volume, bulk gravity, etc., that have taken place. Often the temperatures to which clay refractories are exposed in service are higher than those employed in their firing. However, if the manufacturer were to fire them at such high temperatures the brick would distort. Therefore it would be difficult for the manufacturer to fire all of his clay refractories to temperatures . at which they are to be used, although in many cases it would be desirable from the user's point of view if he would do so. The porosity of clay refractories decreases by firing, to a minimum limit, after which a further increase in the temperature causes expansion in certain clay constituents and bloating in others. -Both may occur in the same refractory containing two such clays.

Jan 1, 1944

By B. F. Oliver, C. W. Haworth

Pure tin and Sn-0.5pct Pb ingots have been frozen unidirectionally from the base. For quiescent melts that were initially undercooled, a transition from lower eqlciaxed structure to an upper columnar structure is found in the alloy ingots. Columnar to equi-axed back to columnar transitions are observed in superheated alloy ingots, but no such equiaxed band is observed impure tin. The reproducible equiaxed band is associated with a thermal undercooling followed by a recalescence. This undercooling is <5"C, whereas the critical (maximum obtainable) under-cooling for both the pure tin and the alloys used is -20°C. A similar undercooling is observed at the same position in the pure tin ingots, although in this case no clear transition in structure can be seen. The structure of the pure tin ingots is either entirely columnar or mixed columnar-equiaxed. A consideration of the detailed thermal history of the ingots indicates that the ingot macrostructures are determined by the occurrence of a local therlnal undercooling in conjunction with nuclei multiplication and transport mechanisrris. GENERALLY it is found that a pure metal ingot solidifies so as to produce an entirely columnar structure. Frequently an alloy ingot is found to have a columnar outer zone and an equiaxed central portion. Early systematic work to examine the factors controlling the formation of the equiaxed structure was reported by Northcott&apos; who showed that, for copper alloys frozen unidirectionally with a given ingot practice, the alloying element influenced the length of columnar crystals and the extent of the equiaxed structure. Northcott showed that alloys with a wider freezing range more readily produced the equiaxed structure. The nucleation process can be important in producing equiaxed structures; frequently an alloy which readily solidifies with an entirely columnar structure will produce an entirely equiaxed structure when a nucleating agent is added to the melt.&apos; The formation of the equiaxed structure was attributed by Winegard and chalmers3 to the presence of constitutional supercooling; that is, a region of liquid in front of the growing solid could have a temperature below its equilibrium liquidus temperature. Thus, with a small enough temperature gradient in the liquid, it was suggested that the presence of constitutional supercooling may be sufficient to bring about the nuclea-tion necessary for the formation of an equiaxed structure. Although this explanation is plausible, and may be relevant in many ingots, Walker has described an experiment&apos; for which constitutional supercooling seems to be an unlikely cause of nucleation. A Ni-20 pct Cu alloy, repeatedly undercooled more than 50"C, was crystallized and found to show the typical colum-nar-equiaxed structure. The separation between the liquidus and the solidus for the alloy is 40°C. Thus, in this experiment the nucleation required for the formation of the equiaxed structure must have come about in some other way than by the nucleation catalysis constitutional supercooling hypothesis. Chalmers has suggested more recently5 that nuclei (in a typical ingot) are present immediately after pouring and are prevented from redissolving by the constitutional supercooling effect. More recently Uhlman, Seward, Jackson, and ~unt&apos; have shown direct evidence using ice and organic materials that freeze dendritically that the "remelt mechanism" may be an extremely effective crystal multiplication process during the freezing of ingots under conditions involving dendritic growth. JSlia" experimentally demonstrated the detachment of dendrite arms. chernov14 has analyzed the dendrite arm detachment process as a coarsening phenomena driven by the minimization of interphase area. Katta-mis and ~lemings" working with undercooled steel melts give evidence supporting this mechanism. Mechanisms of dendrite arm detachment such as those assisted by convection are believed to be the origin of the macrostructures obtained in this study. This study makes no attempt to distinguish the relative contributions of these mechanisms. The object of the present work was to obtain accurate temperature measurements during the solidification of an ingot and to correlate these measurements with the formation of equiaxed grains in the resulting ingot structures. Similar previous work is very limited. The measurements carried out by Northcott are neither sufficiently extensive nor sufficiently accurate for any interpretation. Plaskett and winegard7 carried out experiments on A1-Mg alloys in which they observed values of the temperature gradient, G, in the liquid and rate of freezing, R (for a given alloy solute content Co), at the transition from a columnar to an equiaxed structure. They reported that equiaxed crystals were produced at values of G/G approximately proportional to the solidus composition. Similar experiments using Pb-Sn alloys carried out by £111011" showed a linear relation between G/R and the solidus composition. However, the thermocouples were in the mold wall rather than in the melt and, in one case, ingot surfaces were examined. There is ambiguity in the meaning of the values of G and R measured in all these experiments. APPARATUS AND EXPERIMENTAL PROCEDURE Alloys were prepared by induction melting 99.999 pct Sn and 99.999 pct Pb to form a Sn-0.5 wt pct Pb alloy in air in a graphite crucible and casting into a cylindrical graphite mold 6 in. long, 1 in. in diarn , and with a & in. wall thickness. This mold was mounted on a copper base through which cooling water could be

Jan 1, 1968

By C. Ernest Birchenall, Robert F. Mehl

Application of diffusion laws in the customary form to experimental studies in binary metallic solid solutions has shown the diffusion cocfficient to vary with concentration for all systems investigated. The factors determining this variation have not been ascertained. However, the question of whether the diffusion coefficient would become a constant, independent of concentration throughout a single phase if the concentration gradient in the diffusion equation were replaced by an activity gradient has been an attractive subject for speculation. Wagner¹ derived an expression for the force acting on a diffusing particle in terms of the chemical potential. This was also the approach chosen by Jost2 in his monograph. From a somewhat different point of view, Eyring3 and his co-workers have used activity gradients when dealing with diffusion in concentrated nonideal solutions. The only actual test with experimental data is that given by Darken,4 though this is more qualitative than quantitative. Many others opposed the application in any way of thermodynamic concepts to kinetic phenomena, including diffusion processes. A rigorous examination of this principle requires good data expressing the relationship between activity and concentration for solid solutions for which reliable diffusion work has been done. The literature provides such information only for the interstitial solution of carbon in gamma iron (austenite) and for the substitutional copper-zinc solutions (alpha brass). Activity data for carbon in austenite at 800°C and 1000°C are available from the recent work of Smith5 on the equilibrium of hydrogen-methane and carbon monoxide-carbon dioxide mixtures with gamma iron. Combining these with the diffusion studies of Wells and Mehl6 makes possible a quantitative test for this interstitial solid solution. The vapor-pressure determinations for zinc over brass by Hargreaves7 allowed the calculation of activities in this system over a wide range of temperatures and concentrations. Extensive investigation of diffusion in this substitutional solid solution has been carried out by Rhines and Mehl.8 Activities in Brass9 If the vapor phase of zinc is assumed to behave as an ideal gas, any solid or liquid solutions that are in equilibrium with the same partial pressure of zinc at the same temperature have the same thermodynamic activity of zinc. In order to assign a numerical value to the activity azn, it is necessary to choose some standard reference state to which an activity value of unity is arbitrarily assigned. It is customary to choose the liquid or solid state of the pure material. Then azn is defined numerically by

Jan 1, 1947

By C. Ernest Birchenall, Robert F. Mehl

Application of diffusion laws in the customary form to experimental studies in binary metallic solid solutions has shown the diffusion cocfficient to vary with concentration for all systems investigated. The factors determining this variation have not been ascertained. However, the question of whether the diffusion coefficient would become a constant, independent of concentration throughout a single phase if the concentration gradient in the diffusion equation were replaced by an activity gradient has been an attractive subject for speculation. Wagner¹ derived an expression for the force acting on a diffusing particle in terms of the chemical potential. This was also the approach chosen by Jost2 in his monograph. From a somewhat different point of view, Eyring3 and his co-workers have used activity gradients when dealing with diffusion in concentrated nonideal solutions. The only actual test with experimental data is that given by Darken,4 though this is more qualitative than quantitative. Many others opposed the application in any way of thermodynamic concepts to kinetic phenomena, including diffusion processes. A rigorous examination of this principle requires good data expressing the relationship between activity and concentration for solid solutions for which reliable diffusion work has been done. The literature provides such information only for the interstitial solution of carbon in gamma iron (austenite) and for the substitutional copper-zinc solutions (alpha brass). Activity data for carbon in austenite at 800°C and 1000°C are available from the recent work of Smith5 on the equilibrium of hydrogen-methane and carbon monoxide-carbon dioxide mixtures with gamma iron. Combining these with the diffusion studies of Wells and Mehl6 makes possible a quantitative test for this interstitial solid solution. The vapor-pressure determinations for zinc over brass by Hargreaves7 allowed the calculation of activities in this system over a wide range of temperatures and concentrations. Extensive investigation of diffusion in this substitutional solid solution has been carried out by Rhines and Mehl.8 Activities in Brass9 If the vapor phase of zinc is assumed to behave as an ideal gas, any solid or liquid solutions that are in equilibrium with the same partial pressure of zinc at the same temperature have the same thermodynamic activity of zinc. In order to assign a numerical value to the activity azn, it is necessary to choose some standard reference state to which an activity value of unity is arbitrarily assigned. It is customary to choose the liquid or solid state of the pure material. Then azn is defined numerically by

Jan 1, 1947

By R. H. Sweetser

AT the Buffalo meeting in October, 1898 (Trans., xxviii., 865), our Secretary, Dr. Raymond, in speaking of the obstacles he had encountered in securing contributions to the Transactions from members in practice, said: "It is the disinclination of many members to communicate incomplete or partial or preliminary results. They are going to write, &apos; some day,&apos; a thorough and monumental paper; and meanwhile they prefer to communicate nothing. . . . It is the difficulty to which I have just referred that I have encountered in a wide correspondence with members, undertaken for the purpose of securing contributions of fact and opinion concerning the special subject of this discussion. . . . Almost none of them seem to recognize the value of preliminary, incomplete and indecisive reports of practice, as laying the foundation for a thorough inquiry." This remark was made in immediate reference to a discussion concerning blast-furnace tuyeres ; but, notwithstanding this appeal from the Secretary, little has been recorded regarding the distribution, the penetration, and the pressure of the blast at the tuyeres and inside the iron blast-furnace. I am therefore encouraged to contribute the following incomplete and crude observations of the blast-pressure inside the hearth. At the suggestion of J. H. Frantz, the General Manager of the Columbus Iron & Steel Co., a test was made at the East furnace of the company to determine whether there was any difference in blast-pressure at the different tuyeres. The apparatus used for this test was not sensitive enough to give accurate results. It consisted of a small pressure-gauge mounted on a 3/8-in. gas-pipe. A hollow plug, fitting into the peep-hole of the tuyere-cap, prevented the blast from blowing-out during the test. The test-pipe was held in place by means of the handle on the outer end.

Mar 1, 1909

By AIME AIME

ALTHOUGH the present economic depression is felt in the petroleum industry, probably as much as in any other branch of American industry, the Petroleum Section of the Institute was well represented at the general sessions on Monday and at all of the seven division sessions on Tuesday, Wednesday and Thursday. The seven sessions of the Division were so arranged as not to conflict and thus permitted members to hear the programs of all sessions.* The first meeting of the Petroleum Division was held on Tuesday afternoon; a joint session on engineering research and production engineering. The following papers were presented:

Jan 1, 1931

By A. Steiner, K. L. Komarek

Activities of aluminum in solid Ni-A1 alloys have been determined between 20 and 60 at. pet Al and 1200" and 1400°K by an isopiestic method in which nickel specimens, heated in a temperature gradient, are equilibrated with aluminum vabor in a closed all-alumina system. The activity of aluminum shows a strong negative deviation from Raoult&apos;s law at low concentrations but increases by three orders of magnitude within the ß(NiAl) phase. The partial molar enthalpy and entropy of mixing are negative. Using Wagner and Schottky&apos;s theory of ordered compounds, a degree of disorder of 4 x 10 -4 for NiAl and 1.25 X 10-2 for FeAl has been calculated THE Ni-A1 system has been studied by a great number of investigators, and the results, as far as the phase diagram is concerned, have been compiled by Hansen.1 The phase boundaries from 0 to 50 at. pet Ni are well-established. At higher nickel contents the boundaries are still in dispute and an additional phase, A12Ni3, has been reported.&apos; The phase diagram is dominated by a very stable high-melting compound, NiA1, with a relatively wide range of homogeneity. Heats of formation of solid alloys have been determined calorimetrically by Oelsen and Middel3 from 20 to 95 at. pet Ni and by Kubaschewski4 from 25 to 80 at. pet Ni. According to the most recent compilation5 no other thermodynamic investigations have been reported for the Ni-A1 system. Due to the corrosive nature and the low vapor pressure of aluminum, a method has been employed for determining activities of aluminum which was previously developed for the Fe-A1 system.= Nickel specimens, heated in a closed evacuated alumina system in a temperature gradient, were equilibrated with aluminum vapor from a source within the system kept at constant temperature. After complete equilibration the specimens were analyzed and activities calculated from the known vapor pressure of aluminum. APPARATUS AND EXPERIMENTAL PROCEDURE Materials. The nickel specimens were made from wafers of electrolytic nickel (International Nickel Corp.) of 99.99 pet purity which were rolled to a 0.001-in.-thick foil by Driver-Harris Co. and to a 0.005-in.-thick sheet in our laboratory. The aluminum (Aluminum Corp. of America) had a purity of 99.99+ pct. The alumina tubes and crucibles were made of impervious recrystallized alumina with an alumina content of 99.7 pet (Triangle RR, Mor-ganite Inc.). Experimental Procedure. Annular specimens were punched from the sheet, the punching burrs removed, and the specimens degreased in carbon tetrachloride and acetone and weighed on a micro-balance to within an accuracy of ±0.01 mg. The specimens were positioned with alumina spacers along an alumina tube, and the positions measured. Aluminum metal was machined into cylindrical shape, and placed into an alumina crucible. The tube with the specimens was then inserted into a hole drilled into the aluminum metal. An alumina tube with its closed end at the top was slipped over the specimens so that its lower end fitted snugly into the alumina crucible. The assembled reaction tube was inserted into a mullite tube with a water-cooled brass head which had an opening for a quartz thermocouple protection tube and a metal-to-glass connection to a conventional vacuum system. A Pt-Pt 10 pet Rh thermocouple could be raised and lowered in the quartz tube which was placed along the outside of the alumina reaction tube. The mullite tube was heated by two separately controlled resistance-tube furnaces so that in the experimental temperature range an over-all temperature gradient of approximately 150o to 250°C could be imposed on the reaction tube. The position of the mullite tube was adjusted so that the surface of the aluminum metal was always at the temperature minimum. The reaction tube was thoroughly evacuated before and during slowly heating the assembly up to the melting point of aluminum. A pressure of less than 2 µ (Hg) was maintained during an experiment. Once the aluminum had melted, it isolated the contents of the alumina tube from the surroundings. Several times during an experiment the temperature gradient was carefully measured. An experiment lasted from 3 to 6 weeks and it was terminated by air cooling the evacuated mullite tube. For further details of the experimental procedure the paper on the Fe-A1 system6 should be consulted.

Jan 1, 1964

By Felix B. Shay

The Agua Fria mine is in eastern Honduras at Lat. 140" 06&apos; N., Long. 86" 36&apos; W. Danli, the seat of the local municipal government, is the nearest town. The property is approximately 44 miles east of Tegucigalpa, the terminus of a truck road from the Pacific coast. The mine lies at an altitude of 3300 ft. with surrounding elevations as high as 6000 feet. For 20 years the oxidized croppings of the Agua Fria vein had been worked intermittently when in 1927 an attempt was made to open the property. A shaft was sunk 300 ft. and considerable ore was blocked out, but before a mill could be installed financial difficulties arose and the mine reverted to the original owners. Erle Y. Halliburton, of Los Angeles, purchased the property in 1934. At that time a careful consideration of all factors involved showed that air transport was the only practical method of moving the equipment and machinery necessary to commence production. The other alternative was by muleback, which required sectionalizing all equipment to a maximum load of 200 lb., and during the rainy season this type of freighting was subject to serious delays. It was decided to purchase a trimotor Ford powered by three Pratt and Whitney Wasp B motors developing 400 hp. each. There were several reasons for the choice: (1) this type of plane was available at a reasonable price, owing to its replacement by faster models on most of the airlines in the United States; (2) the ship was capable of carrying a pay load of 3000 Ib. over the required distance; (3) since this airplane had been widely used there would be no difficulty in securing competent personnel or in purchasing spare parts. It was necessary to rebuild the plane for cargo servicc. The windows were removed and the fuselage was entirely covered. A hatch was cut in the top of the fuselage to receive heavy crane loads and pieces of freight that were too large or too long to go through the rear door. The seats were removed and the interior of the plane was lined with Duralumin sheets. A heavy-duty landing gear was installed and the floor was reinforced. The nearest site for an airport was two miles north of the mine. The necessary grading was done by a small track-type tractor with a wheeled grader, which was brought in overland. Six weeks was required for bring-

Jan 1, 1940

By Felix B. Shay

The Agua Fria mine is in eastern Honduras at Lat. 140" 06&apos; N., Long. 86" 36&apos; W. Danli, the seat of the local municipal government, is the nearest town. The property is approximately 44 miles east of Tegucigalpa, the terminus of a truck road from the Pacific coast. The mine lies at an altitude of 3300 ft. with surrounding elevations as high as 6000 feet. For 20 years the oxidized croppings of the Agua Fria vein had been worked intermittently when in 1927 an attempt was made to open the property. A shaft was sunk 300 ft. and considerable ore was blocked out, but before a mill could be installed financial difficulties arose and the mine reverted to the original owners. Erle Y. Halliburton, of Los Angeles, purchased the property in 1934. At that time a careful consideration of all factors involved showed that air transport was the only practical method of moving the equipment and machinery necessary to commence production. The other alternative was by muleback, which required sectionalizing all equipment to a maximum load of 200 lb., and during the rainy season this type of freighting was subject to serious delays. It was decided to purchase a trimotor Ford powered by three Pratt and Whitney Wasp B motors developing 400 hp. each. There were several reasons for the choice: (1) this type of plane was available at a reasonable price, owing to its replacement by faster models on most of the airlines in the United States; (2) the ship was capable of carrying a pay load of 3000 Ib. over the required distance; (3) since this airplane had been widely used there would be no difficulty in securing competent personnel or in purchasing spare parts. It was necessary to rebuild the plane for cargo servicc. The windows were removed and the fuselage was entirely covered. A hatch was cut in the top of the fuselage to receive heavy crane loads and pieces of freight that were too large or too long to go through the rear door. The seats were removed and the interior of the plane was lined with Duralumin sheets. A heavy-duty landing gear was installed and the floor was reinforced. The nearest site for an airport was two miles north of the mine. The necessary grading was done by a small track-type tractor with a wheeled grader, which was brought in overland. Six weeks was required for bring-

Jan 1, 1940

By H. S. Price, J. C. Cavendish, R. S. Varga

This paper presents a new technique for solving some of the partial differential equations that are commonly used in simulating reservoir performance. The results of applying this technique to a simple problem show that one obtains accurate pressure values near wells, as well as accurate pressure pdients, which can be explicitly calculated. The method is completely rigorous in that convergence of the discrete numerical solution to the continuous solution for both pressure and pressure gradient is established. High-order, piecewise-polynomial approximations are used near the wells where pressure gradients are steep, while low-order, piecewise-polynomial approximations are used elsewhere to reduce greatly the calculation time. This combination is shown to give a uniformly good approximation to the solution. These approximations, obtained by using a Galerkin process with suitable Hermite subspaces, are shown to be theoretically and numerically superior to the usual approximations obtained from standard finite-difference techniques. Not only are much greater accuracies obtained, but computer times are also greatly reduced. The application of this technique to multiphase flow problems (e.g., single well coning problems) would have considerable practical interest, but such extensions of this technique with full mathematical rigor have not been made as yet. However, the numerical methods presented here are general, and in principle extend to multidimensional, multiphase flow. Moreover, the preliminary results given in this paper are sufficiently encouraging that we feel the effort in attempting these extensions is justified. INTRODUCTION The problem of obtaining accurate pressure distributions and pressure gradients around wells is of considerable importance in the numerical simulation of reservoir performance. The most common approach to solving this problem is to use finite difference techniques (see McCarty and Barfield9 or Peaceman and Rachfordl0). This approach, however, has many disadvantages, the major one being that many grid points are generally necessary for accurately describing the pressure distribution and the pressure gradient around wells. This need for a fine grid results in large computer times and often in prohibitively high costs. Besides investigating the method of finite differences, some authors, such as Welge and weber17 and Roper, Merchant and Duvall,13 have considered a combination of analytical and numerical techniques with some success. These approaches, however, are all nonrigorous and quite often cannot even be applied. In this paper, we present a numerical formulation of high-order accuracy, based on the Galerkin method, for solving this problem. We treat here only the partial differential equation that describes steady-state, single-phase flow. However, the methods presented are general and in principle extend to multidimensional, multiphase flow. Specifically we treat special cases of the problem in two dimensions described by: where G is a rectangle (with sides parallel to the coordinate axis) with boundary ?G, ?/?n denotes the outward normal, and y and B are non-negative constants such that y + B > 0.

Jan 1, 1970

By C. H. Stewart, R. A. Fagin

A two-dimensional, three-phasereservoir simulator was programmed for a large memory digital computer. It was designed to provide a practical solution to describing the complex physical relation between the natural forces and the physical properties of a heterogeneous reservoir when subjected to a specific set of conditions. A reservoir study is briefly described to illustrate application of the model. A full volumetric account of three phases (oil, gas and water) is performed simultaneously throughout an integration net representing the reservoir. Absence of one or two of the phases is treated as a special case of the more general situation. Expansion (or contraction) of all phases, including rock expansion, is performed so that the pressure calculation is the general unsteady-state case. To account for the large variations of subsurface elevation encountered in some reseruoirs, and to allow for segregation of the various phases, a gravity head term is included in the basic drive potential. Appropriate fluid and rock properties are used in polynominal surface form (functions of pressure and/or depth) or they can be entered as space variables at each position of the integration net. An unsteady-state water influx calculation, based on the method of van Everdingen and Hurst, l was connected to the boundary of the matrix to simulate aquifers of various sizes. In addition to reservoir calculations, three-phase fluid flow from the producing depth to the wellhead, including provisions for gas lift, was incorporated in the simulator. A workover routine was also built which can automatically switch to a different set of production relations when a gas-oil ratio or water fraction reaches a limit; or it can shut-in the well if prescribed. INTRODUCTION This paper describes a reservoir engineering mathematical simulator used to represent the complex interaction of natural forces and physical properties of a reservoir during natural depletion or with various injection schemes. The simulator, which was programmed for a large memory digital computer, is a two-dimensional calculation which handles three mobile fluid phases simultaneously (oil, gas and water). Basic requisites for the method are individual well production and pressure data, hydrocarbon fluid properties, geological data (producing depth and net sand), capillary pressure data, relative permeability data and permeability and porosity information. Matching the past performance of a combination drive reservoir often has yielded information concerning continuity and the validity of basic data. Detailed predictions of future performance can be made for continuation of current depletion methods (natural depletion) as well as for various types of recovery by gas or water injection. Combination injection cases and pattern studies can also be performed. Workover programs, gas lift and different types of artificial lift programs have been investigated using a technique similar to that described by Kern and Nicholson2 except that conditions of pressure and saturation at the block within which the well is located are used rather than average reservoir conditions. Drilling additional wells to optimize profit was explored, both as to number and location, by placing wells at different spots within the reservoir matrix. Special depletion processes can be examined, such as upstructure drainage and lateral (or strike) waterfloods in thin oil columns. In one case the mathematics of the simulator were modified to calculate the displacement in the vertical plane rather than in the horizontal plane. In this manner specific reservoir problems can be studied, such as coning of gas and/or water around production points, fingering along permeable stringers or, more generally, frontal advances in a heterogeneous section.

Jan 1, 1967

By H. W. Straley

Some ten years ago the writer1 made a survey of college catalogues to determine what sort of training geologists were receiving in basic sciences. In the light of this compilation and subsequent experience, he made the statement at the 1939 meeting of the Institute that apparently only in schools offering a curriculum in geological engineering or in the geological option of mining engineering curricula could geologists hope to receive the training advocated by Hubbeet.2 In the former study, schools of engineering were excluded because the preparation was known beforehand. The present study aims to consider engineering schools in an effort to determine not only what basic studies are required but what use is made of them in geological courses of the third and fourth years. The present study combined the method of consulting catalogues with a questionnaire. Letters were mailed to officials responsible for supervision of mineral industries curricula requesting information On&apos; (I) the extent to which the engineering preparation of the first two years is actually used in the work of the last two; (2) the extent to which the engineering of the last two years is used in courses in geological engineering or geology; and (3) whether geologists or geological engineers teach descriptively or analytically. Both methods of securing information are open to criticism; the former on the basis of the incomplete information supplied by university catalogues concerning prerequisites and curricula and the latter on the ground that the questions may be phrased poorly or given insufficient consideration by replying officials. Fifty-six questionnaires were mailed and 39 (70 per cent) replies were received. Of the replies, 6 (11.3 per cent) were from colleges of liberal arts unconnected with engineering schools, 11 (20 per cent) were from schools having curricula in geological engineering and 22 (39 per cent) were from departments of mining engineering. The number of replies and their distribution were satisfactory in spite of the receipt of only six from liberal arts colleges. It should be understood that the universities of which the catalogues were examined were not necessarily the same in both compilations. No departments that are admittedly or known to be acting solely as service departments were recorded in the second study. Table I shows that all professional schools require mathematics through calculus, whereas only 7 per cent of the liberal arts curricula expect the same level of preparation; only 73 per cent require trigonometry and 40 per cent college "algebra. The proportion of geological engineering curricula requiring differential equations is higher than mining. All of the engineering schools require general and analytical chemistry, whereas only 77 per cent of liberal arts curricula require general and 18 per cent analytical. Twenty-two per cent of the mining and 40 per cent of the geological engineering

Jan 1, 1946

By H. W. Straley

Some ten years ago the writer1 made a survey of college catalogues to determine what sort of training geologists were receiving in basic sciences. In the light of this compilation and subsequent experience, he made the statement at the 1939 meeting of the Institute that apparently only in schools offering a curriculum in geological engineering or in the geological option of mining engineering curricula could geologists hope to receive the training advocated by Hubbeet.2 In the former study, schools of engineering were excluded because the preparation was known beforehand. The present study aims to consider engineering schools in an effort to determine not only what basic studies are required but what use is made of them in geological courses of the third and fourth years. The present study combined the method of consulting catalogues with a questionnaire. Letters were mailed to officials responsible for supervision of mineral industries curricula requesting information On&apos; (I) the extent to which the engineering preparation of the first two years is actually used in the work of the last two; (2) the extent to which the engineering of the last two years is used in courses in geological engineering or geology; and (3) whether geologists or geological engineers teach descriptively or analytically. Both methods of securing information are open to criticism; the former on the basis of the incomplete information supplied by university catalogues concerning prerequisites and curricula and the latter on the ground that the questions may be phrased poorly or given insufficient consideration by replying officials. Fifty-six questionnaires were mailed and 39 (70 per cent) replies were received. Of the replies, 6 (11.3 per cent) were from colleges of liberal arts unconnected with engineering schools, 11 (20 per cent) were from schools having curricula in geological engineering and 22 (39 per cent) were from departments of mining engineering. The number of replies and their distribution were satisfactory in spite of the receipt of only six from liberal arts colleges. It should be understood that the universities of which the catalogues were examined were not necessarily the same in both compilations. No departments that are admittedly or known to be acting solely as service departments were recorded in the second study. Table I shows that all professional schools require mathematics through calculus, whereas only 7 per cent of the liberal arts curricula expect the same level of preparation; only 73 per cent require trigonometry and 40 per cent college "algebra. The proportion of geological engineering curricula requiring differential equations is higher than mining. All of the engineering schools require general and analytical chemistry, whereas only 77 per cent of liberal arts curricula require general and 18 per cent analytical. Twenty-two per cent of the mining and 40 per cent of the geological engineering

Jan 1, 1946

By G. Thodos, E. M. Phillips

A reduced density correlation for the gaseous and liquid regions of ethane has been developed from all the experimental PVT data available in the literature for this substance. Saturated vapor and liquid densities reported for methane, propane and n-butane were utilized to establish the rectilinear-diameter line for ethane. This line was then used with the saturated-vapor data for ethane to produce the saturated envelope for this substance. Most of the saturated liquid data reported for ethane were found to be inconsistent with the saturated-liquid curve resulting from this study. The correlation covers the regions 0.65 < TR <6.0 and 0 < PR < 15. For regions for which no experimental data have been reported, the isobars of the correlation were extended by the use of the theorem of corresponding states. This correlation is presented both on rectilinear and log-log coordinates. INTRODUCTION At the present time, there is considerable interest in the exact PVT behavior of pure hydrocarbons. Matschke and Thodos12 recently have developed a comprehensive compilation of experimental vapor and liquid density data for methane. Similar studies have been conducted for other pure substances.4, 7 In the present study the density data available in the literature for gaseous and liquid ethane have been critically reviewed and utilized to develop a reduced density correlation for this substance. SATURATED LIQUID AND VAPOR DENSITIES The rectilinear-diameter rule proposed by Cailletet and Mathias5 states that the sum of the saturated liquid and vapor densities of a pure substance is a linear function of temperature which passes through the critical point. This law, although empirical, has been well established by continued verification since its conception in 1886. This rule has been applied to the saturated density data of methane,6 propane 17 and n-butane8 to produce the straight lines presented in Fig. 1 which pass through the critical point TR = 1.00, Pr = 2.00. The rectilinear-diameter relationship for ethane was established from the lines for the other substances in Fig. 1 by plotting the quantity p~, + PR against zc for different reduced temperatures. A critical analysis of the saturated vapor and liquid densities reported for ethane by Kuenen,10 Maass and McIntosh,11 and Sage, Webster and Lacey18 revealed that the values of PR1 + pr resulting from these studies were inconsistent with the rectilinear-diameter line obtained from the reliable density data of the other substances, as shown in Fig. 1. In the analysis of these data, reduced quantities were calculated using the critical con-