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Experimentation which measures differences in pressure across the interfaces of immiscible fluids in the interstitial spaces of porous media may be termed "capillary pressure experimentation". In the literature of petroleum technology since 1941 there have appeared twelve papers popularizing capillary pressure concepts and developing applications of these concepts for the solution of problems of practical reservoir engineering importance, such as the determination of connate water, fluid distribution. in transition zones, reservoir rock textural properties, and oil recovery from petroleum reservoirs.' Although a review of the literature would be justified at this time in order to reconcile the conflicting viewpoints which are contained in the cited papers, the object of this note will be of more limited scope. It is believed that the recent paper of Muskat alls sufficient attention to many of the uncertainties which arise upon examination of the published literature. such that until satisfactory counter-proposals can be made it will serve our purpose only to mention some other like uncertainties. This will emphasize further the need confronting petroleum technologists to re. consider and reformulate the application possibilities of capillary pressure experimentation. In particular, I sug- gest that we examine the thesis that capillary pressure experimentation as above defined can lead to measurements reflecting the recovery of oil from petroleum reservoirs, as was proposed first" by Amyx and Yuster" and was first reduced to practice by the experimentation of Welge. In fact. I shall deal exclusively with the Welge papers since it is the principle one on this subject which has appeared to date. I shall attempt to show that the possibility of describing oil recovery features in terms of capillary pressure phenomena has not been established entirely. The Welge paper was a pioneering effort to evaluate this recovery application possibility. P. P. Reichertz' comments on the Welge paper state that non-wetting phase discontinuities are developed occasionally in the Welge experiment, and restate Muskat's argument that discontinuous fluid elements (partially saturating the interstices of porous media which are elsewhere saturated with some other immiscible phase or phases) are not subject to the requirements of hydrostatic equilibrium. It is the purpose of my comment to show that it is unnecessary to make Reichertz' postulation regarding non-wetting phase discontinuities (however valid) when it is desired to criticize welge's theoretical treatment of his problem. It can be shown that Welge's method of measuring values for ''capillary pressure" is invalid in many instances of application, such that his reported curves of capillary pressure Versus fluid saturation often have no physical meaning, even throughout the interval of fluid saturation where it might be otherwise suspected that no phase discontinuities occur. By considering established principles of capillary pressure experimentation it can be shown that the pressure difference experimentally observed between wetting and non-wetting fluid Phases which are contained in external reservoirs will reflect on the capillary pressure difference at the interfaces of contact between these phases only when the following conditions are satisfied: (a) There shall be a balance between the opposing forces of gravity and capillarity, as obtains under conditions of hydrostatic equilibrium when the positions of the interfaces of contact become fixed in pore spaces of certain geometry (b) The wetting and non-wetting fluids within the interstitial spaces shall everywhere be continuous with the external wetting phase reservoir and the external non-wetting phase reservoir, respectively. It will become apparent immediately that in any instance when a greater pressure is recorded in the external wetting phase reservoir than in the external non-wetting phase reservoir, one may establish either that static equilibrium has not been attained or that discontinuities in one or more of the fluids have been developed. This is because the pressure otherwiee is always ereatest in the non-wetting phase at each static interstitial interface of contact with the wetting phase. such that the externally measured pressure in the non-wetting phase likewise must be greatest if the above conditions are to be satisfied.

Jan 1, 1949

By Thomas M. Drown

THE means relied on to attain uniformity in Bessemer steel may be enumerated as follows : I. The appearance of the flame. II. The appearance of the slag. III. The spectrum of the flame. IV. Examination of the steel itself. At present, I wish briefly to bring forward a few considerations with reference to the last two mentioned, namely, the conditions favoring the employment of the spectroscope and examination of the steel. From the amount of careful investigation which has been devoted to the examination of the Bessemer flame by the spectroscope, both on the part of scientists and practical metallurgists, one might reasonably expect some results definite and satisfactory in their nature, first, as regards the nature of the flame, and second, as to the practical value of the spectroscope as a guide in conducting the process. We find, in fact, however, that uncertainty and confusion still exist. In Germany, where this subject has received the greatest attention, it is now very generally conceded that manganese is the cause of the well-known groups of dark bands that characterize the Bessemer spectrum. Nor is it easy to see how we can avoid accepting this conclusion, when Wedding and Von Lichtenfels have produced the manganese spectrum and found it to correspond closely with that shown by the Bessemer flame. But it is evident, on a moment's reflection, as Roscoe has recently brought forward, that manganese cannot be the only cause of the Bessemer spectrum, for we notice the characteristic bands quite as

By Adrian C. Dorenfeld

Concentradora "Doña Aida" (100 t /d capacity) was built in 1971-72 to treat dumps and ores containing mixed oxide-sulfide copper-gold-silver minerals derived from two veins. The veins, Don Felipe and Maria, are about 150 m apart, but are distinctly different mineralogically. The deposits are near Sun Juan de Guadalupe, Durango, Mexico. All new process equipment was manufactured locally, in or near Torreon, Coahuilu. Sampling, ore testing, flowsheet design, plant design, drawings, purchasing, financing, and construction, etc., were planned and directed by two engineers. Construction was executed by local miners and common labor (largely agricultural). The paper presents detailed costs for equipment and construction. The subsequent breaking-in operation is discussed.

Jan 1, 1982

By H. M. Katz, J. L. Speirs, F. B. Hill

Jan 1, 1961

Prof. G. W. MAYNARD, New York City (communication to the Secretary): Prof. Christy, in his admirable paper on "The Growth of American Mining Schools," has overlooked the work done by the Rensselaer Polytechnic Institute in its department of mining and metallurgy. This oversight is naturally due to the fact that the department was, for lack of money, discontinued in 1871. It was organized by the writer in 1867, starting with ten students, who had already completed the first two years of the civil engineering course in the Institute. The course covered two years, specifically devoted to mining, metallurgy and assaying, which, in connection with the two years' drill in the civil engineering department made a four years' course. During the four years of the existence of the department, thirty-five students took the course, of whom twentyfive graduated; and of this number eight have been members of the Institute of Mining Engineers, and the majority of them have occupied high positions in the profession. The equipment of the department was, at that time, second only to that of the Columbia School of Mines. As Prof. Christy has cited other institutions which are not distinctively mining schools, but in which the ruining course was subordinate to other courses, it seems to me that the work in this line carried out by the oldest engineering school in the country may very properly be referred to. In addition to the regular mining course, a special course in assaying was given; and many young men were here prepared for positions in the mines and metallurgical works of the west. PROF. George F. Swain, Boston, Mass.: I have listened with great interest to Prof. Christy's valuable paper, but there is one conclusion at which he arrives that appears to me entirely unjustifiable, and to which I desire to take exception. Prof. Christy finds that of the total wage-earners in the United States in 1880,10.41 per cent. were employed in " trade and transport;" 20.24 per cent. in " manufactures and mechanics," and 1.83

Jan 1, 1894

By G. Kinder, R. Gilges, W. Stoker, R. Davey

The Bingham Canyon Mine, located 48 km (30 mi) southwest of Salt Lake City, Utah, is operated by Kennecott Copper Corporation's Utah Copper Division. This operation is the world's largest open-pit copper mine and produces 96 000 tons (106,000 st) ore and 327 000 tons (360,000 st) waste each day. This material is loaded by large electric shovels and transported by both truck and rail haulage. To meet the requirements of the Clean Air Act of 1970 (as amended), new facilities for the control of smelter emissions were required and are now nearing the final stages of construction. The facility will be capable of treating all the output from the mine, some 2,530 tons (2,789 st) per day of combined concentrate and precipitate. Costing $280 million and necessitating the replacement of reverberatory furnaces with continuous smelting vessels, the plant, with its massive and complex gas handling and acid-making facility, is required to remain on-stream with the minimum of pollution control equipment outages to conform with Federal Regulation 52.2325.

Jan 8, 1978

Jan 1, 1898

[†ADAIR, ARTHUR C., Corp 4th Co., 1st. Training Bat., 154th Depot Brigade. ADAMS, HENRY, Major Chemical Warfare Service. ARLUCK, A. A Headquarters, 1St Corps of Artillery. ASKIN, THOMAS B. H Ensign.] [ ]

Jan 1, 1925

By Andrew B. Crichton

No more important question has come before the coal industry in the past decade than the prevention of stream pollution by mine drainage; especially in Pennsylvania, where large areas of coal land have been developed. It may be thought that the problem of labor or lack of transportation outweighs in importance that of stream pollution. We can see possible remedies for labor and transportation problems but there is no known satisfactory solution of the mine-drainage problem. The subject has been given little serious attention, for, until recently, it has been little understood; but in the past year it was brought to the attention of the coal-mining industry by the introduction, in Congress, of several bills designed to prevent the discharge of acid waters from mines or other sources into navigable streams, or their tributaries. The first legislation proposed was the Applebybill, H.R.7369, designed particularly to prevent the oil pollution of coastal waters. It contained the following provisions, which the coal men regarded as referring to the coal industry. It shall be unlawful to throw ... any refuse matter of any kind ... into any navigable waters of the United States or into any tributaries of any navigable waters from which the same shall float or be washed into such navigable waters. The chemical, steel, paper, and other manufacturing industries, as well as the mining industry, objected to this clause, the miners claiming that it would prevent the discharge of waste or mine drainage into any waters of the United States, for all streams or tributaries finally reach navigable waters. The next bill introduced was that of Congressman Briggs, H.R. 7430, an amendment to Section 13 of the Pollution Act of March 3, 1899. The original act referred chiefly to oil and oil refuse, but it provided also "that no material of any kind should be deposited on the bank of a navigable water, or tributary, which might reach the waters and interfere with or

Jan 1, 1923

By Andrew B. Crichton

No more important question has come before the coal industry in the past decade than the prevention of stream pollution by mine drainage; especially in Pennsylvania, where large areas of coal land have been developed. It may be thought that the problem of labor or lack of transportation outweighs in importance that of stream pollution. We can see possible remedies for labor and transportation problems but there is no known satisfactory solution of the mine-drainage problem. The subject has been given little serious attention, for, until recently, it has been little understood; but in the past year it was brought to the attention of the coal-mining industry by the introduction, in Congress, of several bills designed to prevent the discharge of acid waters from mines or other sources into navigable streams, or their tributaries. The first legislation proposed was the Applebybill, H.R.7369, designed particularly to prevent the oil pollution of coastal waters. It contained the following provisions, which the coal men regarded as referring to the coal industry. It shall be unlawful to throw ... any refuse matter of any kind ... into any navigable waters of the United States or into any tributaries of any navigable waters from which the same shall float or be washed into such navigable waters. The chemical, steel, paper, and other manufacturing industries, as well as the mining industry, objected to this clause, the miners claiming that it would prevent the discharge of waste or mine drainage into any waters of the United States, for all streams or tributaries finally reach navigable waters. The next bill introduced was that of Congressman Briggs, H.R. 7430, an amendment to Section 13 of the Pollution Act of March 3, 1899. The original act referred chiefly to oil and oil refuse, but it provided also "that no material of any kind should be deposited on the bank of a navigable water, or tributary, which might reach the waters and interfere with or

Jan 1, 1923

Assaying, mineralogy, and geology appear in ancient records as early as mathematics, physics, and chemistry. Agricola was the first author to unify the earth sciences, the mineral extractive industries and the mineral processing industries. His text, De Re Metallica, published in Latin in 1556, is recognized as the first technical literature. In 1702 mining instruction was started at Freiberg, Germany. The purpose of this school was to train skilled workers, a program corresponding to present-day, on-job, vocational-technical, upgrading extension training. Formal instruction in mining engineering began at Schemnitz, Hungary, in 1763, at Freiberg, Germany, in 1766, and at St. Petersburg, Russia, in 1773. It is interesting to note that these three schools initiated instruction in mining engineering before formal instruction in civil engineering began at Paris, France, in 1775. Early mining engineering, 1763-1900, was expected to cover all eventualities in the mineral industries. Optional curricula were offered early in the 20th Century but did not reach into all branches until after World War I. Specialization crystallized during World War II under three organic units: (1) Earth Sciences; (2) Mineral Engineering; (3) Mineral Technology, the three together constituting the mineral arts and sciences of the modern world (Fig. 10).

Jan 1, 1950

By James B. Fletcher

Leaching of the block caved mine from 1941 through 1970 is described, and the improvements made are listed. Detailed is the increased knowledge of leaching gained through this operation, including methods used in forecasting production, prediction of the economical end point, rate of recovery, and ultimate recovery.

Jan 1, 1972

By R. H. Lee

WITHOUT doubt, one of the most frequent and serious annoyances connected with the practical running of a blast-furnace, especially in single-furnace plants, is caused by low steam, in spite of the fact that all boilers at blast-furnaces have grates for burning coal, and that coal is more or less continuously burned upon them, from three to a dozen men being pretty constantly engaged around the boilers as firemen or coal- and ash-handlers. At times, when the furnace is ? tight," all available men are put on to assist the regular firemen; yet sufficient steam cannot be got to keep the engines up to their regular number of revolutions, while the stoves, deprived of the gas which has been sent to the boilers, run cold, so that, when the furnace loosens-up and resumes the regular rate of driving, the blast is very considerably below normal temperature, and a.' cold," or at best a " high-sulphur," east is the result. Again, it often happens that a furnace, running at its best, becomes temporarily a little too hot; the pressure rises; the amount of gas made' is diminished; the steam soon commences to go down; and a small scaffold is likely to form before the furnace has been brought back to the proper rate of driving, and thus enabled to take its regular amount of blast. The usual remedy is either to "jerk" the furnace by a sudden, brief intermission in blowing, or to cool the furnace by lowering the heat of the blast; but if the lower blast-temperature be maintained too long, the hearth and descending stock may be cooled below the " critical temperature " mentioned by Mr. .Johnson, and the furnace may go to the other extreme, and become cold. This is especially the case when coal or coke, high in sulphur, is used:

Jul 1, 1906

By Ernest R. Lilley

While American scientific literature contains much information upon geologic conditions controlling the production of oil in Rumania, copper in Chile, and other fuel and metallic resources in many foreign countries, it is singularly lacking in data about the nonmetallics outside of the United States. Thus, though the United States is the outstanding market for European high-quality refined kaolin, and for the chinaware, porcelain, and other products of the European ceramics industries, American literature contains only the briefest references to the deposits from which the raw kaolin utilized is obtained. To the writer, to whom has come in the past year the opportunity of visiting a number of these deposits personally, they have proved of extreme interest both commercially and geologically. It is the latter phase that is discussed in this paper. The older and now largely crystalline rock areas of France, Germany, and other parts of western Europe contain numerous pegmatite dikes of which the upper portions have been subjected to surface weathering and kaolinization in much the same way as those of the eastern portion of the United States. Like the latter, the European pegmatite kaolins have long been known for their freedom from iron and other impurities offensive to the china and porcelain manufacturer. Unfortunately, they are also, like the American deposits, individually of small size and noted for their high costs of production. Deposits of sedimentary clay similar in many respects to the high-quality sedimentary kaolins of Georgia and South Carolina are known and worked, notably in southern Germany and in the Newton Abbott district of Devon and Dorset in England. In general, their relationship to the parent rock from which they were derived is more evident than in the United States and the individual deposits are of smaller areal extent and less regular in outline. While these deposits are of considerable economic importance they did not, because of their similarity to deposits in America, attract and hold the interest of the writer to the extent that several other types of deposits did. It is to the latter, which are so different from the kaolin

Jan 1, 1932

By P. J. Closmann

Jan 1, 1914

By H. A. Wahl, J. M. Campbell

This study extends our information on solid-liquid slurries to the flow of sand in horizontal fractures. Inasmuch as this is basically an unsteady-state process, a comprehensive photographic study was undertaken in a 10-ft windowed cell to determine if the basic flow regimes described for steady-state flow in pipes applied to the subject process. Since the number of potential variables far exceeds the capacity of a single study, emphasis has been placed on the effects of sand concentration, oil viscosity and oil flow rate. The extensive photographic evidence obtained has proven very valuable in gaining an insight into the basic flow mechanisms. Being able to follow visually the flow characteristics that accompany the quantitative data is valuable in the application of the results. Although the use of dimensionless parameters was carefully investigated. it was found that the data obtained could be more easily, and as accurately, correlated by judicious use of the dimensional variables investigated. However, a study into the feasibility of scaling slurry flow was made in the event this technique is justified in future investigations. The data presented show that the pressure behavior observed in solids transport in pipes basically applies to slurry flow in horizontal fractures. The roles of the parameters are altered but a basic equivalence exists. The most significant correlating parameter was the oil viscosity (µo) and the bulk velocity of the slurry (vn), expressed as ''µv" product. The most significant correlation expresses the rate of advance of the sand as a function of the variables investigated. There are many practical ramifications of this phase of the investigation that should aid in better treatment design. Evaluation of sand advance rates provides a means of estimating sand placement efficiencies during a treatment and the resulting sand distribution in the fracture. The results show that sand placement efficiencies are low under typical treatment conditions. A brief description of the effects of overflushing is also included. INTRODUCTION The flow of sand-oil slurries in fractures is an area in which little basic knowledge is available. This stems to some degree from the fact that it is impossible to duplicate fractures at the surface. They occur in various shapes and sizes with an infinite combination of irregularities. Unfortunately, we can never "see" these fractures except in cores and by indirect means of measurement. In spite of this inherent difficulty, it is desirable to develop some basic concepts that will provide a better understanding of the sand transport mechanism. An insight into the problem is provided by investigations of fluid flow in rectangular conduits. Several studies on the flow of liquids in non-circular conduits1,13 show that a Reynolds number-Fanning friction factor relationship can be written if the hydraulic diameter is substituted for the regular diameter in a circular pipe. This hydraulic, or equivalent, diameter is taken as four times the cross-sectional area occupied by the flowing fluid divided by the wetted perimeter. Eq. 1 expresses an extension of this same work when applied to infinite parallel planes b distance apart.' Eq. 1 is a theoretical equation expressing the friction factor as a function of the Reynolds number for laminar single-phase fluid flow. This expression has been verified experimentally. The equivalent expression for a smooth circular conduit differs only in that the value of the constant is 16 instead of 24. Numerous studies have related friction losses to Reynolds number in both circular and non-circular conduits. These results are widely used and are not reviewed here. Huitt' investigated the effect of surface roughness on fluid flow in simulated fractures. He concluded that fluid flow in fractures may be treated similarly to fluid flow in circular conduits. This work, together with that of Nikuradse,' shows that surface roughness has no appreciative effect upon the resistance to flow in the viscous flow region. In the region of turbulent flow, surface roughness is a prominent factor. Hydraulic conveyance literature is another important source of information. Durand3 has attempted to organize systematically the variables involved in hydraulic-solid transport in pipes. He has classified the modes of flow into three types according to the size of the particles in the mixture— homogeneous mixtures, intermediary mixtures and heterogeneous mixtures. With the usual concentrations and flow rates used in hydraulic transportation, particles with diameters of less than 20 or 30 microns form eszentially homogeneous mixtures with water. The data show, however, that even small materials will tend to settle out under laminar flow conditions. Mixtures containing solids over 50 microns in diameter do not achieve total homogeneity even under turbulent flow conditions. Particles from 50 microns to 0.2 mm in diameter may be transported in fully suspended flow at normal transport velocities although the concentration in the vertical plane is not uniform. Above 2 mm in diameter solid materials are transported along the bottom of the conduit at a velocity substantially less than that of the liquid itself. Between 0.2 and 2 mm in diameter, the particles tend to be in a transition zone between heterogeneous suspended flow and deposit flow at normal hydraulic transport velocities. The sand sizes used in fracturing usually fall in this size range. It is interesting to note that the grain size range designated by Durand for this transition zone corresponds closely to the transition zone between

By AIME AIME

SHORTLY after he started his professional career, the subject of this sketch acquired the sobriquet "Moose" Allen. At the time he was engaged in geological exploration it1 the Canadian wilds. The nickname was given .him because of the wide, straight trail that he broke with unusual speed when going through the bush. Like a moose he was strong, energetic, and determined. To a considerable degree, Rolland Craten Allen today displays the same characteristics in larger affairs-business, civic, and professional. It is his habit to study a problem thoroughly, to decide u11on the best course of action, and then to pursue that course with vigor and

Jan 1, 1936

Jan 1, 1949

Jan 1, 1939