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By B. K. Miller, George E. Moore

THE Missouri fire clays are here divided into plastic and semiplastic clays occurring as widespread bedded deposits in east central Missouri and flint and diaspore clays occurring as isolated "sink-hole" deposits in the north central Ozark region. Visual inspection was the first method used in clay prospecting. Thin overburden, hard sandstone "rimrocks," and the occurrence of diaspore float made this method particularly applicable in the flint and diaspore fields. The first drilling tool used was a hand auger. One man can drill 25 to 50 ft. per day at a cost of about 35 cents per foot. Holes can be drilled to a depth of 150 feet. Spud drills are often used where the over burden is hard. This drill uses a slotted earth socket bit. A two-man crew can drill about 100 ft. per day at a cost of about 35 cents per foot. Mechanically powered auger drills have been used extensively in wildcat drilling in the past few years. This type of drill furnishes a continuous set of cuttings. The practical depth limit with this drill is 50 to 60 ft. Two men can drill 300 ft. per day at a cost of about 20 cents per foot. Core drilling is used mainly to prove a known clay deposit. A two-man crew with a No. 22 Sullivan drill can drill about 30 to 40 ft. per day in soft clay, at a cost of about $1.25 per foot.

Jan 1, 1947

By A. J. Garnier, N. H. van Lingen

Rock downhole is known to be lesc. drillable than when brought to the surface. This must be ascribed mainly to the presence under downhole conditions of a pressure differential across already made chips, which hinders their being lifted. The pressure differential has partly a static and partly a dynamic origin. Balling-up of bits is another consequence of this pressure differerztial. Reduction in penetration rate owing to an increase in the strength of the rock is governed by the difference between the mud pressure and the pressure of the for/nation pore liquid. Rotationally symmetric geostatic stresses have 170 effect on drillability. Fracture of rock when drilling will be brille in most cases. The above is supported by laboratory drilling experiments with drag bill and roller bits an elevated mud, pore, and confining pressures On rocks differing in strength and permeability. INTRODUCTION In oil well drilling drillability of rock is found to decrease with increasing depth of the hole. Naturally deep rock will be more compacted and, therefore, harder to drill than shallow rock of the same type. However, apart from this the drillability of a sample of deep and compacted rock brought to the surface is generally much higher than in its original location downhole. In view of the economic implications of this reduction in drillability, it seems worthwhile to analyze its causes. The origin clearly has to be sought in the difference of environment. The only conceivable factors would seem to be the presence of mud under pressure, the pressure of the formation pore liquid, and the overburden of the rock. Down the borehole the rock is compressed triaxially by mud pressure and overburden. It is well known that the strength of rock is increased when confined by external pressure1. Various authors have, therefore, ascribed the difference in drillability mainly to the strengthening of rock by triaxial compression. Another factor, mentioned by Bobo and Hoch5, is that forces. including "pressure differential forces", tend to hold a dislodged particle in place. However, the conditions determining their magnitude are not clarified nor is their effect on drilling rate assessed. In the laboratory, drilling experiments on pressurized samples of rock yielded evidence that pressure differential forces holding the chips down are the major factor in reducing rate at depth. This paper describes the experiments and shows how the results enable both a qualitative and a quantitative interpretation of the factors determining the effect of chip hold-down on drilling rate. The implication with respect to balling-up and jet action is also discussed. The greatcr part of the experiments were performed in the pressure vessel shown in Fig. 1. The spacc between the sample of rock and the vesscl is divided by "0" rings into three separate chambers. The rock sample is confined laterally by pressurized oil in thc middle chamber. Penetration of oil into the sample is prevented by partly jacketing it with brass foil. Thc pressure of the drilling fluid in the hole can be adjusted via the upper chamber. Permeable rock specimens arc water saturated before being drilled. With a properly plastering mud as drilling fluid the pressure of the pore water can be adjusted independently via the lower chamber.

By Mark C. Malamphy

The occurrence of outcrops of bituminous schists and sandstones impregnated with heavy asphaltie petroleum first directed attention to the São Pedro area as a possible source of commercial production of petroleum. Since 1920, more than 20 wells have been drilled in this area. The discovery of oil shows and small quantities of natural gas in some of the early wells led to the continuation of drilling in the hope that more important findings would result. During the early part of 1934, detailed magnetometer observations were made in this area, and a considerable number of torsion balance stations were occupied. The results of these geophysical observations help considerably to clarify the structure of the area and the very considerable amount of geologic information available makes possible a much more exact interpretation of geophysical anomalies. In presenting the results of these observations, and interpretation of the geophysical data, certain actual case problems are included; i.e., geophysical anomalies due to anomalous masses of which the forms and positions are more or less known. Although anomalies due to igneous intrusions are probably more important to geophysicists in Brazil than in other countries, these data have a certain interest for all geophysicists, particularly because they were obtained in the south magnetic hemisphere, where the lines of magnetic force are directed upward, and in a region of moderately low inclination. This is considered as a geological-geophysical problem, and only passing mention will be given to the petroleum possibilities of the area. General Geology The location and general geology of the São Pedro area are shown in the sketch map of Fig. 1, which is adapted from the geologic map of South Brazil compiled by Oppenheim1,†- who gives the geologic column of South Brazil (So Pedro and vicinity) as follows:

Jan 1, 1940

By Mark C. Malamphy

The occurrence of outcrops of bituminous schists and sandstones impregnated with heavy asphaltie petroleum first directed attention to the São Pedro area as a possible source of commercial production of petroleum. Since 1920, more than 20 wells have been drilled in this area. The discovery of oil shows and small quantities of natural gas in some of the early wells led to the continuation of drilling in the hope that more important findings would result. During the early part of 1934, detailed magnetometer observations were made in this area, and a considerable number of torsion balance stations were occupied. The results of these geophysical observations help considerably to clarify the structure of the area and the very considerable amount of geologic information available makes possible a much more exact interpretation of geophysical anomalies. In presenting the results of these observations, and interpretation of the geophysical data, certain actual case problems are included; i.e., geophysical anomalies due to anomalous masses of which the forms and positions are more or less known. Although anomalies due to igneous intrusions are probably more important to geophysicists in Brazil than in other countries, these data have a certain interest for all geophysicists, particularly because they were obtained in the south magnetic hemisphere, where the lines of magnetic force are directed upward, and in a region of moderately low inclination. This is considered as a geological-geophysical problem, and only passing mention will be given to the petroleum possibilities of the area. General Geology The location and general geology of the São Pedro area are shown in the sketch map of Fig. 1, which is adapted from the geologic map of South Brazil compiled by Oppenheim1,†- who gives the geologic column of South Brazil (So Pedro and vicinity) as follows:

Jan 1, 1940

Jan 1, 1910

By C. D. Woodward

PrioR to 1902, the tramming of ore from the stopes to the shafts, in the Butte mines, was done by man or animal power, but the demand for greater tonnage and the need for more improved methods of tramming the ore resulted in the installation of the compressed-air locomotive in a few mines. Some of the objections to animal haulage were thus eliminated, but this locomotive was not generally adopted, because of a number of limiting features. It was superseded by the electric trolley locomotive. The early types of trolley locomotives were not satisfactory from the operators' viewpoint, but they had many economic advantages and after a number of years, in which improvements were constantly made in the structural details, they became dependable, so that the use of animals for main haulage in the mines has now been practically abandoned. There are now operating in the Butte mines of the Anaconda Copper Mining Co., 185 trolley-type locomotives, each of which has replaced five animals. It cost approximately $50 per month to keep an animal, hence the economies that resulted fully justified the expenditure of electrifying the haulage systems. The haulage conditions in this company's mines possess many advantageous features that arc not always found in underground mine workings. The drifts and crosscuts are large, approximately 5 ft. (1.5 m.) wide by 71/2 ft. (2.3 m.) high, and have curves of no less than 18 ft. (5.5 m.) radius; and the roadbeds of the drifts and crosscuts have a uniform grade of 0.5 per cent. toward the shaft, or in favor of the loaded trips. In all of the mines, except two, the track gage is 18 in. (45.7 cm.): and all tracks in the main haulageways are laid with 25-lb. (11.3 kg.) rails. The stations at the shaft are large, well-lighted, clean, and cool. The average temperature of the stations, however, is about 75" F. (24" C.), while the average temperature in some of the drifts and crosscuts is 92" I?. (33.5" C.). As the orebodies lie at varying distances from the hoisting shafts,

Jan 1, 1923

By C. D. Woodward

PrioR to 1902, the tramming of ore from the stopes to the shafts, in the Butte mines, was done by man or animal power, but the demand for greater tonnage and the need for more improved methods of tramming the ore resulted in the installation of the compressed-air locomotive in a few mines. Some of the objections to animal haulage were thus eliminated, but this locomotive was not generally adopted, because of a number of limiting features. It was superseded by the electric trolley locomotive. The early types of trolley locomotives were not satisfactory from the operators' viewpoint, but they had many economic advantages and after a number of years, in which improvements were constantly made in the structural details, they became dependable, so that the use of animals for main haulage in the mines has now been practically abandoned. There are now operating in the Butte mines of the Anaconda Copper Mining Co., 185 trolley-type locomotives, each of which has replaced five animals. It cost approximately $50 per month to keep an animal, hence the economies that resulted fully justified the expenditure of electrifying the haulage systems. The haulage conditions in this company's mines possess many advantageous features that arc not always found in underground mine workings. The drifts and crosscuts are large, approximately 5 ft. (1.5 m.) wide by 71/2 ft. (2.3 m.) high, and have curves of no less than 18 ft. (5.5 m.) radius; and the roadbeds of the drifts and crosscuts have a uniform grade of 0.5 per cent. toward the shaft, or in favor of the loaded trips. In all of the mines, except two, the track gage is 18 in. (45.7 cm.): and all tracks in the main haulageways are laid with 25-lb. (11.3 kg.) rails. The stations at the shaft are large, well-lighted, clean, and cool. The average temperature of the stations, however, is about 75" F. (24" C.), while the average temperature in some of the drifts and crosscuts is 92" I?. (33.5" C.). As the orebodies lie at varying distances from the hoisting shafts,

Jan 1, 1923

BETWEEN the third and twentieth days of November, 1903, six intensely interesting letters were mailed from Santiago, Chile, addressed to "Mr. William Braden, Consulting Mining Engineer, 71 Broadway, New York City." The subject of these communications, referred to as the "Rancagua mines," was a copper property situated in the high. Andes; and the writer was Marco Chiapponi, an Italian mining engineer. Many a letter has been written about potential mines and prospects, good and bad, situated in all parts of the world; but few of them combine the shrewdness, sincerity, naïveté, and salesmanship that appear in these fascinating letters by Chiapponi. In 1894, Mr. Braden, as a young man twenty-three years old, had gone to Santiago to look after the erection and operation of some mining machinery that was to be exhibited at the International Mining Exposition. Not the least important of his purposes was to get acquainted at first hand with the mines and mining men of Chile, which ranked at the time (as it does today) second to the United States as a copper-producing country. It happened that a dispute arose regarding charges for certain construction work done in connection with young Braden's exhibit. Finally, arbitration was agreed upon and the Chilean exposition officials proposed Se[n]or Marco Chiapponi as a fair-minded neutral to decide the question. This he did in a manner satisfactory to both sides, and subsequently he and Mr. Braden became good friends. Nine years later Braden wrote to Chiapponi inquiring as to certain matters connected with the Corocoro copper mines in Bolivia. It was to this letter that Chiapponi refers in his letter of November 3, from which the following are some extracts,

Jan 1, 1933

By Henry Lewelling

An experimental investigation of the relative effectiveness of standard bullets and "shaped charges" in perforating dense, hard formations is reported. A method is described which simulates the conditions under which a shot is normally fired. Results are evaluated on the basis of depth of penetration, extent 01 Fracturing. extent and nature of formation damage, and other physical characteristics. INTRODUCTION A study was made of the relative merits of bullets and "shaped charges'' as applied to well completions in hard, dense formations such as those encountered in the Permian Basin. The planning of the laboratory program stipulated that core samples should be prepared and mounted in such a way that perforation shots of either kind"" could be fired into them, keeping the factors pertinent to good shooting practice similar to what they would be in a well. The shooting was done in a buried tank. with the sample and shooting equipment covered with water. The depth of water was calculated to he sufficient to simulate the inertial effects of well fluids for the duration of an explosion (a few micro-seconds). Flow measurements were attempted on the specimens after perforation. Due to the lack of uniformity of the limestone, shale breaks. etc., these measurements proved to be of little value to the study. The mounting materials were removed. so that the character of the penetration. fracturing, etc., could be observed. METHOD Laboratory samples were selected from the hard. dolomitic sand cores from Block 31 Field. Core pieces having a 3 3/4 in. diameter and a useful length of 10 to 12 in. were used. Selection was aimed at those pieces having a minimum of shale streaks and other irregularities. The ends were cut off square Manuscript received in the Petroleum Branch office June 28, 1951. Paper presented at the Petroleum Branch Fall Meeting in Oklahoma City, Okla., Oct. 3-5, 1951. with the diamond saw. Prior to lbeing mounted. the cores were soaked in water to prevent them from absorbing water out of the wet concrete, thus weakening it. A set of steel capsules was fabricated for holding the core Samples. Seven-in. casing was cut in two-ft lengths. of which one end was closed by "orange-peeling" and welding, and the other was threaded to accept a standard bull plug. The bull plugs were fitted with copper tube connections .so that pressure could be applied when the capsules were made up. The cores were mounted in the capsules by means of wire centralizers whose function was to hold the Core in proper position while concrete was poured and set. A special aggregate was prepared wing a graded sand and gravel mixture

Jan 1, 1952

By Louis A. Panek

Caving of previously undisturbed ground was conducted for a period of about 20 months at two locations about 600 m (2000 ft) apart in an Arizona porphyry copper deposit. When mining was suspended the width of the mined zone at both sites was on the order of one-half the depth and the thickness of ore extracted was only a fraction of the rock column. Thus the results have potential application to predicting the subsidence above a cavern-type excavation. Break cables were used to detect the upward progress of caving. Analytical aerotriangulation was used to determine the vertical and horizontal displacements of 400-plus surface targets covering a 1585 m (5200 ft) square area. The measurements are summarized and interpreted with a view to predicting the rate of rise of a caving brow, detecting the initial surface subsidence, and characterizing the extent, the location, and the varying degrees of expected damage to surface facilities.

Jan 1, 1984

By H. S. Price, J. E. Warren

Techniques for studying the performance characteristics of heterogeneous reservoirs have been developed. The effect of permeability variation on both the steady-state and the transient flow of a single fluid has been investigated. Limited comparisons with field and laboratory data have been made. The physical models studied consist of random three-dimensional arrays of homogeneous porous blocks. The permeabilities of the individual elements are assigned according to a specific distribution function; uniform anisotropy is introduced by varying the relative dimensions of the blocks. A particular model is perturbed simply by re-arranging its elements at random. The behavior of a physical model is determined by digitally solving its numerical analogue. Based on computational experiments, subject to the restrictions implied by the assumptions that were made, the following general conclusions have been drawn. 1. The most probable behavior of a heterogeneous system approaches that of a homogeneous system with a permeability equal to the geometric mean of the individual permeabilities. 2. The effects of flow geometry and anisotropy on the most probable value of the effective permeability of a heterogeneous medium are finite but not significant. 3. The permeability determined from a pressure build-up curve lor a heterogeneous reservoir gives a reasonable value for the effective permeability of the drainage area. 4. A qualitative measure of the degree of heterogeneity and its spatial configuration are obtained from a comparative study of core analysis and pressure build-up data. It has been indicated that these conclusions are predicated on the assumption that the core analysis and the pressure build-up data represent true reservoir characteristics. Common sources of error in these data have been discussed. One of the most significant problems of reservoir engineering is that of determining the nature and the disposition of the heterogeneities that inevitably occur in petroliferous formations. It is with this problem that this paper is concerned. Extensive research, both theoretical and experimental, has provided reasonable descriptions of the physical processes that are associated with primary and secondaryrecovery mechanisms. Similar progress in the fie1d of numerical analysis and the evolution of truly high-speed digital computers have made it feasible to calculate the behavior of these mechanisms under almost any environmental conditions. It appears to be logical, then, to conclude that the mechanistic performance of any reservoir can be predicted with some confidence. Unfortunate1y, a necessary condition for the validity of this conclusion is that the formation be adequately described in a macroscopic sense. This condition cannot be satisfied ill general; therefore, a frustrating situation currently exists — it is possible to compute the effect of reservoir heterogeneity on behavior, but it is not possible to specify the heterogeneity itself. In many cases, the predicted behavior of a project is so completely dominated by irregularities in the formation's physical properties that the gratuitous assumptior, of a particular form for the variation can reduce the solution of the problem to a mere tautological exercise. While all porous media are microscopically heterogeneous, only macroscopic fluctuations need be considered since the fundamental concepts of reservoir mechanics are based on macroscopic quantities. For the simplest case in which only one physical property varies from point to point, the degree of heterogeneity that is apparent depends on three distinct factors, i.e., the nature of the property's variation (frequency distribution), its disposition (spatial distribution) and the inherent stability of the mechanism being studied. Consequently, any attempt to devise an unambiguous scale of heterogeneity must take these factors into account. Since this investigation is intended to be exploratory, it will be restricted to single-phase flow because of the simplification implied; both steady-state and unsteady-state behavior will be considered. Furthermore, to keep the number of parameters

By D. A. Elgillani, M. C. Fuerstenau, M. C. Kuhn

The species responsible for flotation when xanthate is added as collector for pyrite is dixanthogen. Measured oxidation potentials of these systems show that xanthate should be oxidized to dixanthogen, and the presence of dixanthogen on the pyrite surface is confirmed by infrared absorption. Zeta potential measurements are presented and related to collector adsorption. In spite of the normal presence of pyrite in most sulfide ore deposits, only a modest amount of study has been devoted to the xanthate-pyrite flotation system in the absence of activators and depressant~.'-~ As a result, little is known about the mechanism of xanthate adsorption on pyrite. From the few studies that have been made, however, a number of significant observations have been forthcoming. For example, the dependence of flotation response on the state of oxidation of the surface was noted in two studies — one conducted by Plante and Sutherland4 and a later one by plaksin.~ In another study, Gaudin and wilkinson3 found that ferric xanthate was not present on a pyrite surface. In a later investigation, however, Gaudin' and his colleagues did extract a small amount of ferric xanthate into benzene when pyrite was ground in an evacuated mill with water, benzene, and xanthate. This quantity was apparently

Jan 1, 1969

By Robert W. Hunt

Having had some twenty years' experience in trying to make good Bessemer steel rails, and now devoting my thoughts and energies to seeing that other people seek the same end, I venture to lay before the Institute some of the conclusions deduced from my practice and observation.

Jan 1, 1889

By C. E. Johnston

In December 1956, International Minerals & Chemical Corp. installed a rope-suspended belt haulage system in its Carlsbad, N. M., potash mine to complement the already existing rail transport arrangement. In this article the author describes when and where each system is used, the advantages and disadvantages of both, and future planning and proposed changes in haulage at IMC. The haulage system at the International Minerals & Chemical Corporation (IMC) potash mine near Carlsbad, N. M., reached a turning point in December 1956 with the introduction of rope-suspended belt haulage. In fact, IMC pioneered the use of this type of belt in the potash industry. Since that time belt conveyance has been employed as an extension of the rail system but not as a replacement of the main rail haulage. IMC's potash mine is located in the Permian Basin, approximately 20 miles east of Carlsbad in Eddy County, N. M. The 800, 850 and 900-ft levels have been exploited. From these levels over 60 million tons have been extracted. The two ore minerals are sylvite (KCl) and langbeinite (K2SO4. 2MgSO4). The principal gangue mineral is halite, with minor amounts of polyhalite, kainite and leonite. Langbeinite is mined on the 850-ft level and sylvite on the 900. The 800-ft level, with both langbeinite and sylvite mineralization, is idle. Mining heights vary from 54 in. to over 10 ft. A room and pillar mining system is used. Geologically, mining is done in the Salado salt formation. The U.S. Geological Survey has classified the 900-ft sylvite level as the first ore zone and the 850-ft langbeinite level as the fourth ore zone. Since the grade of sylvite is low, mineralization at the IMC mine is somewhat irregular and salt horses, are common. Selective mining and a flexible haulage

Jan 1, 1963

By G. R. M. Del Giudice

The term "slime-coating" is not new in the art of flotation; the phenomenon has been observed and described by Taggart;(l)† Taggart, Taylor, and Ince;(2) and by Ince.(3) Notwithstanding that flotation was introduced for the treatment of finely crushed ore, the adverse effects of slimes have been recognized since the earliest days of the process, and the Elmore, Delprat, Potter, and other processes actually specified desliming of the ore prior to treatment. The cause of this trouble has been studied and described by Taggart;(1) Taggart, Taylor, and Ince;(2) Ince;(3) Morrow and Griswold;(4) and by Gaudin and Malozemoff.(5) Old Theory of Slime-coatings At present, so far as published work shows, there seems to be but one theory for the mechanism of slime-coatings. Ince(3) states that they are due to attraction between electrostatic charges of opposite sign on the sulfide and on the slime particles, supporting this theory by migration experiments in the Burton tube. He also used the microscope in conjunction with a glass cell employed by Beans and Eastlack(6) in studying migration, but met with interference from endosmosis. Several attempts have been made in the Department of Mineral Dressing at Columbia University to duplicate Ince's experiments with the Burton tube, but the results have never been convincing. Formation of precipitates which settled through the pulp levels, and evolution of gas at the electrodes, which disturbed the interface between the pulp and the distilled water above it, seriously interfered with observations. However, by use of the migration cell shown in Fig. 1, endosmosis effects and the disturbances due to precipitation and gas evolution were avoided, and distinct and reproducible migrations or absence of migration were observed. The cell was made of bakelite and had platinum electrodes. Objectives were employed which had a working distance of at least three millimeters,1 and the parts of the mounting which came in contact with

Jan 1, 1935

By Alexander Sattman, Anton Homatsch

Jan 1, 1894

Jan 2, 1950

Jan 5, 1953

By Craig R. Barrett, Jack L. Lytton, Oleg D. Sherby

The types of substructures developed during high-temperature creep of (110)[001]-oriented polycrys-talline Fe-3.1 pct Si were examined by electroetching of dislocation sites. Edge dislocations were observed to accumulate adjacent to grain boundaries and poly-gonize perpendicular to their glide planes to form a "Pile-up" of nearly parallel tilt boundaries. The dislocation density developed within the grains during steady-state creep was found to increase with increasing stress. The formation of periodically spaced groups of edge dislocations along grain boundaries was observed, and it was proposed that these formed to relive bending stresses at grain boundary shear .faults. Grain boundary serrations developed at these faults, and it was suggested that this was a result of localized grain boundary migration at the polygonized groups. THE authors have conducted a series of high-temperature creep tests on (110)[001]-oriented poly-crystalline Fe-3.1 pct Si sheet. The creep specimens were examined at various stages of creep by means of electrolytic etching of dislocation sites using the chrome-acetic acid solution developed by Morris.' Hibbard and Dunn2 have demonstrated that the etch pits produced with this technique correspond to single dislocations. It is the purpose of this paper to present and discuss the dislocation substructures which were formed during high-temperature creep at constant stress. EXPERIMENTAL PROCEDURES The polycrystalline Fe-3.1 pct Si sheet employed in this study contained a (110)[001] texture. This texture was quite strong, and the elastic properties of the sheet closely approached those of a single crystal of iron.3,4 A typical analysis in weight percent for this material is 3.1 Si, 0.1 Mn, 0.003 C,

Jan 1, 1965

By Milton E. Wadsworth, J. Brent Hiskey

INTRODUCTION Fifteen years ago a distinguished electrochemist referred to electrochemistry as an "underdeveloped science " In the article in question, Professor Bockris (1) stated that many areas of.natura1 phenomena and applied technology are not perceived as being electrochemically based At that time, this was especially true for much of non-ferrous extractive metallurgy and was a particularly accurate description of hydrometallurgy During the last decade, there has been considerable advancement in applying the theory of electrochemistry to our know1 edge of hydrometallurgical processes and in understanding the mechanisms of underlying electrode reactions. Impressive as these advances are, there is still a growing need for electrochemical research of mineral systems and electrochemical engineering to apply this work in practical situations In a broad sense electrochemistry is defined as the physical chemistry of ions in solution and of phenomena which occur at the electrified interface. Bockris and Reddy (2) refer to electrochemistry as being divided into two fundamental domains, ionics and electrodics ionics is restricted to the behavior of ions in solutions, examples being many familiar redox processes Electrodics represents the main part of electrochemistry, and is the study of charged interfaces and the conditions governing charge transfer reactions across them. Considering hydrometallurgical applications, electrodics suggests the following relationship for a conducting solid (bulk or surface)

Jan 1, 1981