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By M. Muskat, H. G. Botset

Any information that will increase the accuracy of our knowledge of the conditions prevailing in petroleum reservoirs should be of direct value in the determination of the proper operating technique as well as in the estimation of reserves and of ultimate production. The obvious method of obtaining this information is by studying a sample of the reservoir rock and its contents. In any such study, the problem of primary importance and maximum difficulty is that of getting the core to the surface in such a manner that its original fluid content is undisturbed, which has so far proved to be an impossible task. Though it might be rash to say this will never be done, it is certainly safe to assume that a, method for the recovery of a core at the surface in its undisturbed original state may not be developed in the immediate future, and certainly will not be forthcoming without a great deal of costly experimentation. Therefore any information that may be obtained that will help to correlate the state of a core (its fluid saturation) at the surface with its condition at the time it was drilled should be of value to the petroleum industry. The experiments described in this paper were undertaken with the purpose of determining, if possible, any relationship that might exist between the saturation of a core at the surface and its original fluid content. No consideration has been given to the question of contamination by penetration of drilling water, since this problem has been extensively studied by other investigators.1-3 Furthermore, it was regarded as outside the scope of these experiments, which were concerned only with the effect of pressure reduction upon the liquid content of cores. In an experimental study of this sort involving a large number of variables, accurate control of all factors is very important. The essential and obvious procedure is to vary systematically one factor or condition while keeping all the others constant, which necessarily involves a rather protracted and sometimes tedious experimental program. The procedure adopted was essentially very simple, and consisted merely in filling a given core with fluid (gas and oil, gas and water, or

Jan 1, 1939

By Richard Zinszer

Application of electric logs has been used in correlation of subsurface structure to determine the size and shape of the oil reservoir. Such a knowledge is hardly complete until saturation and productivity are determined for the various horizons. It is difficult to use electric logs successfully for this purpose because of the many factors that influence the curves. In this work an effort was made to establish an empirical correlation between formation resistivity for a series of electric-log curves and water saturation and oil productivity of sand. Electric logs were obtained by recording with 10 different electrode spacings through the same interval of a well. In the analysis of these curves all factors except two, a dependent and independent variable, were held constant. The interval studied had been cored and a large number of samples were analyzed in the core laboratory in order to compare the values of permeability and saturation with the measured values of formation resistivity. Results of this analysis indicate: (1) the depth to which mud filtrate enters a sand body, (2) a correlation between permeability and sand resistivity for shallow penetration depths, and (3) that the water saturation for an oil sand can be determined from the measured sand resistivity after making suitable correc- tions for sand thickness. The proceduer in the last method depends on a correction for thickness factor and a theoretical curve. The accuracy of the theoretical curve is now being tested in the laboratory. In an effort to place the analysis of electric logs on a quantitative basis, there is need for a better understanding of the many factors that influence an electric-log curve. These factors may be large differences in sand thickness, permeability of the sand, salinity of the interstitial water, mud resistivity, formation temperature, and other sources. A number of examples were presented by Archie,' which treat the effect of sand thickness on measured resistivity. He compared the true resistivity of a sand with the observed resistivity for sands 8 ft., 16 ft., and 24 ft. thick, and found the observed resistivity Of the 8-ft. sand to be approximately

Jan 1, 1943

By Richard Zinszer

Application of electric logs has been used in correlation of subsurface structure to determine the size and shape of the oil reservoir. Such a knowledge is hardly complete until saturation and productivity are determined for the various horizons. It is difficult to use electric logs successfully for this purpose because of the many factors that influence the curves. In this work an effort was made to establish an empirical correlation between formation resistivity for a series of electric-log curves and water saturation and oil productivity of sand. Electric logs were obtained by recording with 10 different electrode spacings through the same interval of a well. In the analysis of these curves all factors except two, a dependent and independent variable, were held constant. The interval studied had been cored and a large number of samples were analyzed in the core laboratory in order to compare the values of permeability and saturation with the measured values of formation resistivity. Results of this analysis indicate: (1) the depth to which mud filtrate enters a sand body, (2) a correlation between permeability and sand resistivity for shallow penetration depths, and (3) that the water saturation for an oil sand can be determined from the measured sand resistivity after making suitable correc- tions for sand thickness. The proceduer in the last method depends on a correction for thickness factor and a theoretical curve. The accuracy of the theoretical curve is now being tested in the laboratory. In an effort to place the analysis of electric logs on a quantitative basis, there is need for a better understanding of the many factors that influence an electric-log curve. These factors may be large differences in sand thickness, permeability of the sand, salinity of the interstitial water, mud resistivity, formation temperature, and other sources. A number of examples were presented by Archie,' which treat the effect of sand thickness on measured resistivity. He compared the true resistivity of a sand with the observed resistivity for sands 8 ft., 16 ft., and 24 ft. thick, and found the observed resistivity Of the 8-ft. sand to be approximately

Jan 1, 1943

By R. M. Brick, M. A. Williamson

CERTAIN features of the response of copper and brass to deformation and recrystallization remain obscure. The textures obtained on rolled sheet are listed by Schmid and Boas1 as: No adequate explanation has been advanced for the presence of the secondary deformation texture of copper and its absence in brass or for the origin of the cubic recrystallization texture of copper.2 A recent publication3 attempted to rationalize the above empirically described annealing texture of brass on the basis of retention of the (110) [112] rolling orientation plus twinning about the central octahedral poles of the usual secondary (110) [115] orientation. The difference in the textures of annealed copper as compared to 70-30 brass is also shown by the difference in the position of ears for drawn copper, at o° and 90°, as compared with drawn brasses, at 45°, for all compositions between 90-10 and 70-30.4 Data on individual crystals are as yet too few to permit of an analysis of these textures comparable to that of mild steel as made by Barrett and Levenson.5 EXPERITMENTAL METHODS The materials studied included copper specimens cut from the central, equiaxed crystal portion of a tough-pitch wirebar; brass made from this copper and high-purity (99.99 per cent) zinc including alloys of 7 per. cent, 15 per cent, 24 per cent, 29 per cent and 36 per cent Zn and large single crystals of 70-30 brass. Sections ¼ in. thick of the cast polycrystalline copper and brasses were reduced 40 per cent by rolling, recrystallized to a common grain size of 0.045 mm. and then rolled directly to foil 0.002 in. thick. Hardness readings employing both the Vickers and Rockwell machines were taken at intervals during the reduction. For comparison, similar specimens were cross-rolled-i.e., turned through 90 for each pass-and comparable hardness data were secured. Finally sections from the single crystals of brass were cut to obtain the following initial orientations; these sections were rolled, hardness data secured and a complete micrographic record of structural changes obtained:

Jan 1, 1941

By M. Muskat, H. G. Botset

Any information that will increase the accuracy of our knowledge of the conditions prevailing in petroleum reservoirs should be of direct value in the determination of the proper operating technique as well as in the estimation of reserves and of ultimate production. The obvious method of obtaining this information is by studying a sample of the reservoir rock and its contents. In any such study, the problem of primary importance and maximum difficulty is that of getting the core to the surface in such a manner that its original fluid content is undisturbed, which has so far proved to be an impossible task. Though it might be rash to say this will never be done, it is certainly safe to assume that a, method for the recovery of a core at the surface in its undisturbed original state may not be developed in the immediate future, and certainly will not be forthcoming without a great deal of costly experimentation. Therefore any information that may be obtained that will help to correlate the state of a core (its fluid saturation) at the surface with its condition at the time it was drilled should be of value to the petroleum industry. The experiments described in this paper were undertaken with the purpose of determining, if possible, any relationship that might exist between the saturation of a core at the surface and its original fluid content. No consideration has been given to the question of contamination by penetration of drilling water, since this problem has been extensively studied by other investigators.1-3 Furthermore, it was regarded as outside the scope of these experiments, which were concerned only with the effect of pressure reduction upon the liquid content of cores. In an experimental study of this sort involving a large number of variables, accurate control of all factors is very important. The essential and obvious procedure is to vary systematically one factor or condition while keeping all the others constant, which necessarily involves a rather protracted and sometimes tedious experimental program. The procedure adopted was essentially very simple, and consisted merely in filling a given core with fluid (gas and oil, gas and water, or

Jan 1, 1939

By Earl Oliver

The term oil property, in this discussion, includes any type of easement or grant under which petroleum might be produced; it ranges from the mere right to drill on undeveloped wildcat acreage up to a fully developed oil property. The values of an oil property, as thus defined, vary widely according to the use for which it is intended, whether it is from the viewpoint of the speculator, the fraudulent stock promoter, the refiner and pipe-line owner, or the oil producer. The market value of a property is usually a combination of some two or more of these influences, and occasionally a combination of all of them, but we prefer to treat each viewpoint as distinct from the others, allowing the reader to make his own combination in such proportions as his inclination and property seem to require. This paper will treat the subject from the viewpoint of the oil producer. However, the other influences have such bearing on the cost of property to the producer and on the price he might obtain by its sale as to warrant brief discussion of them. Speculation, particularly lease speculation, is a parasitic growth on the oil industry, healthy enough, but of no economic value. The class of property usually dealt in for this purpose is the undeveloped lease. Its speculative value may have some relation to its probable productive value, but most frequently this value is the product of temporary excitement due to local development. The lease speculator, seeking out the trend of development or securing early information regarding a proposed test or a new discovery, immediately secures leases whose market value will be increased when the existence of such development becomes more widely known. His profits are purely unearned increment. Not proposing to spend money in exploration, he can afford to compete in purchase with the operator, who, in addition to bonus paid, must spend large sums in testing out his own acreage and that of the nearby speculator as well. It has a tendency to compel unduly high bonuses. The so-called "checker-board1' system of leasing wildcat acreage by the larger companies is on the same principle of attempting to secure the

Jan 1, 1921

By R. E. Ricksecker, W. M. Baldwin, R. McC. Baker

INTRODUCTION THE development of residual stress in strip during rolling has not been systematically studied. A few scattered papers1-3 mention the existence of residual stresses in rolled strip or touch upon some of their consequences,4 but there is no report of experimental studies in the literature describing the effect of roll diameter, strip thickness, reduction per pass, metal or metal temper on the magnitude of residual stresses developed in strip. A knowledge of the effect of these factors is of utmost importance since the present trend in some mills to roll thicker castings brings the rolling operation directly into that set of conditions which, as will be brought out in the present paper, can develop residual stresses of a high order of magnitude. Fundamentally, residual stresses are developed when a metal is inhomogeneously unloaded from a plastic stress state. A quantitative treatment of the problem requires a reasonably complete understanding of both the plastic stress state existing in the metal during deformation and the elastic stress state that would exist in the metal if the metal deformed as a perfectly elastic body. Our knowledge of either state during rolling is so meager that we can make no more than certain limited predictions. The external stress state* operating between the roll and the metal consists of compressive stresses acting almost perpendicularly to the strip surface but vary [ ] ing in intensity both across the width of the strip and along the length of contact between the roll and the strip. An example of such a stress distribution is shown in Fig I. The nature of the internal stress state, produced by this distribution, is not known. Various investigators,5-7 however, have felt that a qualitative similarity must exist between the internal stress state so produced and that produced in a wide strip that is compressed between two flat-nosed punches. In the latter case the external stress state is represented by a uniformly distributed compressive stress acting perpendicularly over the face of the tool. The elastic internal stress state in this case is complex-the principal stresses showing

Jan 1, 1948

By W. Tovote

This paper is based upon 12 years' experience in the Southwest, including three years that were spent in constant traveling as examining engineer for the Phelps-Dodge Corporation. The material was gathered during rather extensive work in Bisbee, Clifton-Morenci, Globe, and Tombstone, and also on short and rapid trips into most of the mining camps and prospect fields of New Mexico, Arizona, the desert country of California, and as much of Sonora as was safe at the time. My methods of observation and my deductions are not put forward as new or scientific; they are simply rough field methods, based upon short notes, rough sketches, and largely upon memory, which I have found useful for coördinating geological data for the purpose of passing quick judgment on mining possibilities in certain districts exhibiting uniform characteristics. The opportunities for observation have been better these last few years than ever before, due to the unprecedented activity in mining, which has caused the reopening of hundreds of old mines and the starting of even more numerous prospects all over the mining states. Possible Systems of Classification By Geological Provinces There are a number of well defined geological provinces in the territory under discussion, and a study of their individual features is of interest. The following are a few of those that are most striking in their uniformity. 1. The "Desert province," extending roughly from Wickenburg, Ariz., to and beyond Barstow, Cal. In its north-south extent it reaches up to the Colorado River and down into Sonora, but overlaps other provinces. It is characterized by a worn-down basement of schistose and granitic rocks, on which rest remnants of Paleozoic and pre-Paleozoic sediments, including very old limestones. The sediments are disrupted and contorted. Alteration in the mineralized areas is very prominent, especially in the schists and limestones. Cenozoic volcanic rocks, principally of semi-basic composition, have been intruded into this complex and sometimes cover it as lava flows. 2. The "Yavapai schist" province, similar to the one first mentioned, consists of metamorphosed basic and semi-basic rocks. It lies in northern

Jan 1, 1920

By Chas. A. Dobbel

The Chief Consolidated properties are situated in the Tintic mining district of Utah, being included in Juab and Utah Counties, about 70 miles south of Salt Lake City. The drilling referred to in this paper has been carried on in the Chief Consolidated No. Pmine, the Gemini mine, and the Eureka Hill mine at Eureka, the Grand Central mine, above Mammoth, and the Apex Standard mine just south of Dividend. The occurrence of ore through the district is typically in lenses on bedding or breaks, and in connecting pipes, without accurate geometrical trend so that the ratio between the total length of development in drifts and crosscuts to the square feet of ore exposed is very high. A section of one of the western channels (Fig. 1) through the Tintic district, shows, roughly, the irregularities calling for excessive development work, so typical of the Tintic mines. This irregular trend of the ore constantly calls for excessive cutting up of the whole area for offshoots and the connecting links always present. In the planning of prospecting and development, no regular system may be laid out without overlooking some orebodies or segments of orebodies. It was with these facts in mind that Cecil Fitch, the general manager of the Chief Consolidated Mining Co., decided that some method of drilling was the more feasible way of successfully cutting up and bringing about the discovery of ore believed to exist; yet this drilling had to compete with a great margin of cost over crosscutting, as a crosscut in the Tintic district, even though barren, brings out geologic facts that, in many cases, are worth the price of the working itself. Diamond drills met with the success that might be expected in a district that has a reputation for the Gear and loss of diamonds; after 6 or 8 months, this method was discarded on account of the high costs. Simultaneously, a small churn drill outfit was set up underground but a few shifts proved its inapplicability. At the same time, the ordinary hammer drill was used to drive prospect holes with jointed steel. Just what equipment to develop for this work with the hammer drill involved much experimenting, as nothing was found in the literature

Jan 1, 1925

By J. C. Uy, A. A. Burr

A quantitative relationship between the allotropic phase boundaries of zirconium-base binary systenzs and the solute metallic valence is shown through an intermediate thermodynamic parameter. A simplified equation relating this parameter to the phase boundaries is briefly reviewed, and data from the literature are used to show the relationship of this parameter to the solute metallic valence. It has been reported that the solute metallic valence can be used as an index of phase stabilization in zirconium-base binary alloys.' It was shown that the algebraic sign of the slopes of the hcp/bcc phase boundaries of zirconium alloys correspond to the algebraic sign of the metallic valence of zirconium minus the metallic valence of the solute, or, in other words, a solute whose metallic valence is higher than that of the solvent tends to stabilize the high-temperature phase while one whose metallic valence is lower than that of the solvent tends to stabilize the low-temperature phase. Further analysis of the zirconium binary systems has revealed a quantitative relationship between the solute metallic valence and the relative slopes of the two-phase allotropic boundaries. This relationship involves a thermodynamic quantity whose significance can be seen in the following section. PHASE-STABILIZATION PARAMETER Let Qb be the difference between the partial molar heats of mixing of a given solute in the two allotropic phases of the solvent which are in equilibrium with each other at a given temperature, thus A relationship between this term Qb and allotropic phase boundaries has been employed by several au-thors'-= in the evaluation of phase diagrams, and can be briefly derived as follows. Referring to Fig. 1, consider the general case of two allotropic phases, each having a small mole fraction (Xa,Xb) of the solute, in equilibrium at temperature T and atmospheric pressure as represented by the reaction. solute in ß phase =solute in a phase If now a reaction occurs such that an infinitesimal amount of the solute is removed from the ß phase and added to the a phase, there would be a partial molar

Jan 1, 1967

This fund was established in 1929 for support of research and especially refers to non-ferrous mining and metallurgy. It is administered under the Board by a committee consisting of the President and Secretary and three members selected by the Board. HOWE MEMORIAL LECTURE The Howe Memorial Lecture, in memory of Henry Marion Howe, Past President of the Institute, was authorized in April, 1923, as an annual address to be delivered by invitation under the auspices of the Institute by an individual of recognized and outstanding attainment in the science and practice of iron and steel metallurgy or metallography, chosen by the Board of Directors upon recommendation of the Iron and Steel Division. The following were the Howe lectarers for the years indicated: Albert Sauveur—1924 Bradley Stoughton—1927 John A. Mathews—1925 Henry D. Hibbard—1928 William Campbell—1926 John Howe Hall.—1929 JOINT ACTIVITIES The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers, and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties. United Engineering Society This is a corporation organized by the American Institute of Mining Engineers, American Society of Mechanical Engineers, and the American lnstitute of Electrical Engineers, to hold the title and administer the property at 29 West 39th St. In 1916, the American Society of Civil Engineers was admitted, and each society now has an equal one-fourth interest in the ownership, occupancy, and administration of the building. . The cost of this property has been over two million dollars. A. I. M. E. representatives are: Arthur S. Dwight, John V. N. Dorr and H. A. Guess. Alfred U. Flinn, Secretary, 29 West 39th St., New York City. Engineering Foundation This is a fund established by the United Engineering Society in 1915 with a gift of $200,000 from Ambrose Swasey. Subsequent gifts had increased the fund to about $620,000 on March 1, 1929. The income of the fund is used to further research in science and engineering and to advance the profession of engineering and the good of mankind. A research project in alloys of iron is being conducted in

Jan 1, 1929

By J. F. Myers, F. M. Lewis

The purpose of the mill tests reported herein, was to determine the relative power efficiency of fast and slow rod mill speeds on the ores of the Tennessee Copper Co. The tests were carried out at the Isabella Mill of the Tennessee Copper Co. under normal operating conditions. Every effort was made to keep the ore supply and other conditions constant, but it will be noted that some slight variation did occur. The open circuit 6 by 9 rod mill, and ore, used in these tests have been previously described.' Four motor drive pinions were available and the tests were performed in the following manner: each pinion was used to drive the mill for a period of one week. Constant sampling prevailed during the test run, and a composite sample for each speed test was made. Realizing that some slight liner wear took place during the four-week test-run, and that some slight variation of the ore may have taken place, a second and then a third series of four-week test-runs were made with the four different pinions. The screen analysis of each of the three-week run samples at the various speeds were composited and the results are shown in Table 2. The authors feel that the 22 weeks of operation consumed during these test-runs would represent fairly the effect of each mil1 speed. The data of line 37 show that within the error of sampling and plant operation, the tons of minus 65-mesh material generated per horsepower hour was the same at all four speeds. Obviously, rod and liner consumption could not be determined for each mill speed in so short a time. The rod load was maintained at a uniform level throughout the series of tests. The authors have operated rod mills at various speeds over the past several years, and it is their observation that rod consumption is directly proportional to the mill speed. Likewise, that the rod consumption per unit of work performed is a constant, providing that all other operating factors remain the same. It is a well known fact that the efficiency increases in a ball mill as the speed decreases. This is due to lateral segregation of the large and

Jan 1, 1950

By Persifor Frazer

The rocks which cover the east flank of the South Mountain are chloritic schists typical in character. A specimen of this rock from near the Bechtel shaft, Hamilton Ban Township, Adams County, Pa., was selected and analyzed in my laboratory by Mr. C. Hanford Henderson, with the following results: Ignition,........2.740 CaO,..........7.040 SiO,,..........41.280 MgO,.......... 7.486 AI,O,,.........18.480 K,O,..........2.208 Fe,Os,.........9.440 Na,O,.........3.523 FeO,......... 8.200 100. As one penetrates the range by moving westvard, these schists are replaced either by epidotie quartz or by orthofelsite. In the former case, a belt of copper-bearing rock is traversed, but not in the latter case. Inasmuch as this junction of the chloritic schists on the southeast and orthofelsite on the northwest, separated by the epidotic quartz, is several times repeated, we find two or three copper belts arranged in general parallelism to the axis of the chain, because the copper horizon is generally at this junction. Thus, in going west from Fairfield, after entering the low spurs on the South Mountain, one is fairly within the chlorite measures. At the " Virginia Mills " a chlorite schist comes in with a dip of S. 1.5 E.-74 Half a mile up Middle Creek, large numbers of fragments of chlorite schist, decoruposed epidotic matter, and quartz are encountered. The former rock, where in place, dips E. 40" S.-57o. About 4000 feet west of the intersection of this road with the so-called Tape-Worm Railroad, near the house of one Singly, large masses of chloritie schist are found loose on the road. A hundred yards farther west, near a triangle in the road, the latter is less in quantity and much epidotic quartz appears, after which a very large display of orthofelsite succeeds on the left bank of Middle Creek. All these last-mentioned rocks, however, are in fragments. Crossing the stream again a few hundred yards farther On, the chlorite fragments at first preponderate, and then large numbers of both rocks

Jan 1, 1884

By Earnest R. Woakes

Those engaged in pumping from shafts, or other mining works, may be intereited in the following suggestion of what is believed to be a novel method of raising moderate quantities of water against a considerable head. It is admitted that the ordinary Cornish pump, as generally used in mines, is hard to beat, on account of both its extreme simplicity and its easy adaptation to the requirements of mining; its great drawback, however, being the enormous weight of heavy rods and successive plungers that have to be kept in motion, not to mention the necessary " balance-" and " angle-bobs," with all their accompanying friction and wear and tear. It is contended that the following method would, to a great extent, overcome these drawbacks ; though, no doubt, many old miners may say it would also introduce new ones. Possibly, this may be the case. It is only desired that this pump may be judged upon its merits. The chief novelty of the method consists in employing the almost unlimited pressure obtainable from a high column of water, augmented, if necessary, by a hydraulic ram or press at the top, to work a small-diameter piston or plunger at the bottom of a shaft or well. This high-pressure plunger, indicated at E, in Fig. 1, transmits power direct to a larger-diameter plunger, F, constituting, together with the ordinary H-piece, valves, and wind-bore, the actual pump, which raises the water, by column C, to the adit-level or other discharge, placed as far as possible below the head of the high-pressure column A and ram W. It will thus be seen, that it is only necessary to maintain a prmsnre on the small piston, E, equal to that on the larger one, F, by means of the small but high column of water, A, in order to cause F to descend, and thus force the water up through C. The up-stroke is accomplished by a small water-wheel, or other engine, connected to the light rod or wire rope B, this having only to raise the weight of the actual plungers and fill the H-piece with water from the tank or

Jan 1, 1892

By F. E. Wood

Since the earliest discoveries of oil in the Rocky Mountain area the spirit of cooperation in drilling and production programs has prevailed. There has scarcely been a field which has not been developed in an orderly manner through mutual agreement between competitive operators. An appreciable saving has resulted, as many unnecessary wells have been eliminated. We have unit operation plans and agreements which were developed at an early date. Rock River, found in 1918, has been a unit operation. One of the first prorate agreements ever attempted was made in Salt Creek in 1921. Teapot, first developed in 1922, has been a unit operation; the lessee, the Government, and the lessor, one operator. South Casper Creek, found in 1918, has been developed as a unit. Rex Lake, found in 1923, is a unit operation. The list might be extended materially but it serves to indicate that the Rocky Mountain region enjoyed the fruits of unit operation at an early date. It is concluded from this unitization study in the Rocky Mountain region that there is an appreciable saving in both development and production costs as well as the elimination of waste of a natural resource. Certainly, when unit operation conserves an irreplaceable natural resource as well as capital, any legal or political impediment to its successful development will be overcome. If one company supervises the operations in one field, it appears to be a unit operation. This may not be true if the lands involved have been leased from a great number of lessors. Royalty holders create a most intense competitive operation. The Rocky Mountain region has its full quota of such diversified interests. The original study calls for consideration of two types of fields, unit and near-unit operation. This Committee has felt that if an agreement of any character has brought about a saving it is an approach to unit operation. The fields have been classified into four types: 1. Unit Operation.—Any field whereby the competitive drilling-drainage feature is or will be absent in the development and operation of the pool.

Jan 1, 1930

By Barnabas Bryan

In the year 1875, the Pennsylvania Supreme Court, acting on incorrect information concerning the production of oil and gas, established what has become the law of the land for the governing of oil production. While the decision was ideal for the refining monopoly which was completed in that year, there is no evidence that the court was in any way influenced by that refining monopoly. The evidence indicates that the court accepted the view of the royalty owner and independent oil producer. Throughout the life of the refining monopoly it accepted this law, which was so evidently to its advantage in securing cheap raw material. The same policy continued until the development of the exhaustion theory and the entry of the various units of the former monopoly into the production of crude oil. It is curious that no one doubted the new theory of shortage sufficiently to feel the need of changing the law. When the theory entered the economic field sufficiently to raise crude oil prices beyond justification it shortly disproved itself, but by this time the question of split ownership in producing fields made a change from legal error to justice too complicated to be undertaken by the large companies. Not even the ardent advocate of unit operation dared to carry the question to the United States Supreme Court, which has never been asked to pass on the complete question. The impossible position of the producing industry, hemmed in on one side by court law compelling wasteful production and on the other by the national law against cooperation, lasted until the demoralization of 1927 led to cooperation within a state and under state guidance. Since that time control of production has grown with the bringing in of each new field and at this time has the active support of the Department of the Interior in such ways as are definitely legal. As in 1875, the royalty owner and independent producer are opposing by all possible means the rational conduct of the business of producing crude oil. Fluctuation in Investments The investor in oil securities has not been as badly fooled as has the oil man himself. Fig. 1 is designed to show the composite regard of all

Jan 1, 1930

GEORGE S. RICE (written discussion *).-An interesting and important question arose during the coal famine of last winter as to whether the development of new mines should be discouraged on account of the need of labor for the necessary construction and development work at a time of scarcity of labor, more especially as there was an apparent overcapacity of existing mines. The question was referred to the author for his comments, which led to the study of the statistics. The essential results of this study are indicated on the accompanying chart, which illustrates, among other things, the increase in production or consumption, and the estimated maximum production capacity of the bituminous and sub-bituminous mines of the United States. The curves shown are based on data published in the "Mineral Resources" of the United States Geological Survey, and cover the period from 1900 to 1916 inclusive. The following curves have been drawn from the data secured: 1. Average number of days that the mines worked. 2. Yearly total production of bituminous and sub-bituminous mines. 2a. Yearly production of machine-mined coal. 3. Average annual production, equivalent to consumption, for a period of 17 years. 4. Number of coal mine employees each year. 5. Estimated capacity of mines, on basis of 300 working clays in the year. 6. Estimated drop in capacity if no new mines are opened. Considering these curves and the data from which they were constructed: It will be noted that the average number of days the miners worked varied from 193 in 1908 to 234 in 1900, the average being 217. The causes for so many idle days out of the possible total number of working days in the year are well known, namely: (a) Lack of business; (b) lack of cars. Taking the country as a whole, (a) is the important factor, which might otherwise be expressed as being an excess of productive capacity. The yearly production of the mines, which is practically synonymous with consumption, has shown a steady increase, with a few set-backs. An average line has been struck which indicates that the average annual increase of production has been 18 million short tons (16,330,000 metric tons).

Jan 5, 1918

By Geo. Otis Smith

Twelve years ago, the Director of the United States Geological Survey addressed to the Secretary of the Interior a letter calling attention to the government's need for liquid fuel for naval use and pointing out that the rate of increase in demand was more rapid than the increase in production.' This letter, in a way, inaugurated the policy of public oil-land withdrawals, which was well founded in its primary purpose of protecting the oil industry and highly desirable in its immediate effect of checking the over-development of that day in California. Unfortunately, however, through delays in legislation, this policy may be regarded now as having outlived both its intent and its usefulness. In 1908, the country's production of oil was 178,500,000 bbl., and there was a surplus above consumption of more than 20,000,000 bbl. available to go into storage. In 1918, 10 years later, the oil wells of the United States yielded 356,000,000 bb1.—nearly twice the yield of 1908—but to meet the demands of the increased consumption more than 24,000,000 bbl. had to be drawn from storage. Nor is this all of the brief comparison. In 1918, our excess of imports over exports of crude petroleum was nearly 33,000,000 bbl. whereas in 1908 we exported 3,500,000 bbl., which was net, as we had not begun to import Mexican oil. In this period, the annual fuel-oil consumption of the railroads alone has increased from 16,871,000 to 36,714,000 bbl.; the annual gasoline production from 540,000,000 gal. to 3,500,000,000 gal. This record may be taken not only as justifying the earlier appeal for Federal action, but as warranting deliberate attention to the oil problem of today. Need of Future Supply The position of the United States in regard to oil can best be characterized as precarious. Using more than one-third of a billion barrels a year, we are drawing not only from the underground pools but also from storage, and both of these supplies are limited. In 1918, the contribu-

Jan 1, 1921

By Sidney L. Wise, Walter Strache

While the installation of mine bulkheads to retain water under high pressure is by no means a rarity, the following points which arose in the designing and placing of two of these bulkheads may be of interest: The Hibernia magnetite mine, located about 40 miles west of New York, in the State of New Jersey, is partly fillcd with water. This mine is located on an ore lens, the outcrop of which is over a mile long. The ore has been mined from this lens from the surface to a depth of more than 1,500 ft. It was held desirable to separate the old workings from the new, and to allow the former to fill to the 850-ft. level. Two weak places existed between the new and old workings below this Ievel: namely, a temporary bulkhead on the 10th level and a rock bulkhead of indeterminate thickness on the 16th level. When the matter of allowing the old workings to fill was investigated, the fact was developed that if these old workings were filled, the bulkhead on the 10th level would be subjected to a water pressure of about 50 lb. per square inch, and that 200 lb. per square inch would act on the 16th-level bulkhead. As the above-mentioned barriers were not deemed of sufficient strength to permit of these pressures, it became necessary to design and install new bulkheads. Design As the 16th-level bulkhead was required to withstand a pressure of 200 lb. per square inch, it presented some difficulties. A careful consideration of the various types of mine dams now in use led to the adoption of a design of the form of a truncated wedge. In this, the pressure side of the dam is of greater area than the hack, so that the resultant action is similar to driving the wedge. By cutting generous skewbacks in the walls, roof, and floor, this type in reality becomes an invisible arch. The wedge feature tends to compress the materials in the bulkhead, thereby adding to its imperviousness.

Jan 1, 1915

By E. W. Davis

Iron-ORE beneficiation methods are determined largely by blastfurnace requirements. There are still many millions of tons of direct furnace ore in the Lake Superior district and blast furnaces are designed and operated for the most efficient use of this material. Beneficiated ore must be so prepared that existing furnaces may use it without alteration in design or radical changes in practice. Many attempts have been made to develop new furnaces or processes for smelting iron-ore concentrate not suitable for blast-furnace use, but these processes have gained little importance. It is, therefore, the endeavor in beneficiating iron ore to make a product that will give at least as good results as direct furnace ore in existing blast furnaces. The term "beneficiation," as applied to iron ore, does not necessarily mean concentration, but more accurately means "dressing up" the ore so that it is more acceptable to the blastfurnace operators. In modern blast-furnace practice the structure of the ore is quite as important as the chemical analysis. Certainly, the higher the iron content and the lower the silica, phosphorus and sulfur, the more desirable the ore bccomcs; but if the structure is bad, that is, if the blast-furnace gases can penetrate the charge only with difficulty, the ore is undesirable regardless of its analysis. This means that the ore should be as uniform in size as possible and free from fines, and also that the individual particles of ore should be pervious to the reducing gases of the furnace. Structure and purity are the primary requirements for a furnace ore and structure is just as important as purity. Iron-ore beneficiation processes can be divided, therefore, roughly into two main classifications: (1) processes that primarily improve the structure, and (2) processes that primarily improve the chemical analysis. During the past 10 years approximately 25 per cent of the ore shipped from the Lake Superior district has been beneficiated. Of this about half has been crushed and screened, a simple operation that primarily improves the structure but in some cases also improves the analysis slightly. The other half of the shipment of beneficiated ore, amounting to an average

Jan 1, 1935