Search Documents

By C. V. Millikan

Production engineering has continued its rapid progress during the past year. Many engineering efficiencies long practiced in other industries are being rapidly accepted by the oil industry, and every branch of development and production work is undergoing study that is reducing the time and hazard in the drilling of wells even for greater depths, is securing better service from equipment, and is obtaining greater ultimate recovery from the reservoirs. Deviation of Drill Holes Deviation of drill holes probably has attracted greater and wider study than any other subject. Until about one year ago it had been given little attention. Some California operators knew the common magnitude of deviation, but Mid-Continent operators hesitated to believe that holes could be drilled so crooked. The great emphasis and publicity given to the seriousness of the problem resulted in the design of many instruments to record the deviation by chart or photograph. Instruments which would give the direction as well as deviation were not generally favored because of the grave fears of the legal complications which might result if the bottom of a producing well should prove to be on a neighboring lease. With all the instruments available for determining deviation, the use of etching on a glass bottle by hydrofluoric acid is still the most common method employed. The beneficial result of this earnest effort to drill straighter holes is proved by a comparison of deviation of wells completed recently with those completed over a year ago. The time of this change is arbitrarily taken as Jan. 1, 1929, as at that time the operators were aware of the deviation which usually occurred, and most of them were making some effort to reduce it. Table I shows averages of wells completed by several companies. Data on a few wells outside the greater Seminole area are

Jan 1, 1930

By David Burgess, Hershiel H. Hayden

Experiments at the Somerset mine, Colo., under an agreement between US. Steel Corp. and the US. Bureau of Mines are described. A test was made of the tube bundle method of mine air sampling which was developed for European longwall mines; some 300,000 running feet of tubing provided continuous monitoring at 38 locations. Carbon monoxide concentrations were obtained with standard deviations of less than 1 ppm and oxygen concentrations with standard deviations of less than 0.2%. A base level of CO index (ppm CO evolved per percent 0, removed) was determined to be zero to 20 through most of the passageways of the mine. However, in one working section where the coal was initially hot (about 180°F within a pillar) the CO index was demonstrably higher, 120 trending upward to about 60 when smoke appeared and the section was sealed. The data are discussed in terms of laboratory experiments on CO evolution from coals.

Jan 1, 1977

By Carl F. Dietz, Dyke V. Keedy

The problem of drying ores is one that most mill-engvineers are sooner or later called upon to meet, and it may be timely to point out some of the difficulties resulting from such operations from purely a metallurgical and economic standpoint. We mean, in the following pages, to discuss primarily the effect of such operations on the ore. itself, without particular reference to the mechanical or cost features of the subject. That an appreciable tonnage of the ore fed to the usual form of drier, either rotary or stack, is lost, is fairly well appreciated, but we believe that only a few mill-managers know just what their drier-losses amouilt to, and we have found that in most cases they console themselves with the fact that the drier-smoke is not very much discolored, and it is generally believed that the draft is not sufficient to carry away more than a negligible percentage of the values.

Jan 1, 1913

By Roy R. Weil, John A. Dziubek

This paper discusses the use of computer modeling, data manipulation, and mapping of three multi-seam coal properties in the Appalachian coal basin. Each case history represents a slightly different application of computer usage for estimation of reserves and planning surface mine sequencing. This practical use of computers demonstrates the suitability of data processing for normal evaluation of coal properties.

Jan 1, 1983

By Luther Wagoner

HAVING given in a former paper1 the results of assays of sea-water, bay-mud, dredgings from San Francisco bay, etc., and' believing it might be interesting to extend the work to include' some deep-sea dredgings, I procured from the Smithsonian Institution six samples taken by the U. S, steamer Albatross, and marked as follows

Jan 9, 1907

By D. B. Gillies

IN 1938 the Republic Steel Corp. announced that it had leased the ore mines and other property of the Witherbee Sherman Corp. at Port Henry, N. Y. The announcement brought forth an interesting reaction. Two questions were asked repeatedly: (1) Is the iron product high grade? (2) Is there a substantial reserve? The answer to both questions was and is a decided and emphatic "Yes."

Jan 1, 1943

By M. Oka, C. M. Wayman

It has been known for some time1 that (110)b twinning is possible in bct martensite.* Any plane of the form (110) not parallel to the fourfold axis of tetra-

Jan 1, 1969

By H. l. Burghoff, C. H. Mathewson

THE study of the creep of metals under conditions of prolonged loading has received the attention of many investigators for several years and almost innumerable papers have been published on the various aspects of the subject. As it appeared that much could still be learned from a study of single crystals, the present work was carried out to study the effects of temperature and conditions of loading upon the properties and deformation in tension of single crystals of alpha brass containing about 70 per cent copper and 30 per cent zinc. In particular, it was hoped to obtain information from tests below and above the recrystallization temperature of the material, so that properties such as elastic limit, yield point or critical stress, and manner of deformation might be compared for tensile tests at an ordinary loading rate and for prolonged. loading. Accordingly, short-time tensile tests and creep tests were made at room temperature, 300º, 500° and 700°F. The two latter temperatures are above the lowest possible recrystallization temperature of polycrystalline 70-30 brass. PREVIOUS WORK Clarke and White1 have made creep tests of some copper-zinc alloys, including 70-30 brass, and copper-zinc-tin alloys at temperatures both below and above the recrystallization temperature of the materials considered. Hanson and Wheeler have studied the flow and fracture of single crystals of aluminum for short-time and prolonged tensile loading over a range of temperature extending from room temperature to 400°F., their experiments being made without consideration of the orientations of the test specimens. Extensive creep and fracture tests on single crystals of lead at room temperature have been made by Betty3 and by Baker, Betty & Moore.4 Results of the last-named investigation were published while the present work was in progress. Millers examined the elastic limit of zinc single crystals at and above room temperature by means of creep tests, while Miller and Milligan6 reported the results of tests designed to show the influence of temperature on elastic limit of single crystals of aluminum, silver and zinc. The behavior, of iron crystals under static tensile loading at room temperature was reported by Gensamer and Mehl7 while the present investigation was in progress. Their specimens exhibited a well-defined yield point, below which no appreciable creep could be detected. The manner of yielding proved interesting, as the shape of the creep-time curve for the iron crystals differed from the common type of creep curves. Elongation did not begin immediately, or at least was initially very slow. The rate of elongation then increased continuously and finally decreased to zero. This S-shaped type of elongation-time

Jan 1, 1941

By Malcolm C. Bridges, Ian A. Goddard

INTRODUCTION Mount Isa mine is a major producer of both copper and lead-zinc- silver ores. During the 1975/76 year, 4.3 million tonnes of copper ore were extracted at an average grade of 3.4%, and 2.4 million tonnes of lead-zinc-silver ore at average grades of 7.0%, 6.7% and 173 grams per tonnes respectively. Systematic lead-zinc mining has continued for just over 45 years and copper mining for just over 30 years. Virtually all mining is underground. The composite and somewhat schematic longitudinal section of Figure 1 shows the overall distribution of ore at the Mount Isa mine. The mine can be roughly divided into two parts about a central shaft complex: to the north there is predominantly lead-zinc ore and to the south there is copper ore. Underground operations are serviced by three shafts in the central shaft complex (P61, R62 andU62) and another to the south in the copper mining area (X41). Mining is spread over a total strike length of 2.9 km and extends to a depth of 960 m. Currently, lead-zinc ore is being extracted between 15 and 11 levels and is hauled to the central ore-hoisting shaft on 13 and 15 levels. Copper ore is being extracted between19 and 13 levels and is hauled to the central shafts on 19 level. The principal lead-zinc mining methods used now, as they have been over the last ten years, are sublevel open stoping and cut-and- fill stoping, with about equal tonnages of ore from each (Figure 2). Since about 1970, there have been several interesting developments in lead-zinc mining methods and procedures, principally: • the development of an effective method for the recovery of pillars between open stopes and • the evolution of safer and more productive cut-and- fill methods. During this period also, the focus of mining has moved 120 m deeper

Jan 1, 1977

By William H. Callahan

"For his exceptionally successful career as a geological mentor, for his ore-finding skills, and particularly the discovery of the Central Tennessee Zinc District and for his lecture, 'Prospecting in the USA-Promise and Problems.' " Recipient of the 1982 D.C. Jackling Award

Jan 1, 1983

By G. M. Roberts

During the six years that the writer was connected, as chemist and chief assayer, with the Proprietary Mines, Broken Hill, N. S. W., several interesting experiments were made in the sampling of the silver-lead bullion obtained from the waterjacket smelting-furnace.

Jan 1, 1899

By Albert Arents

This test is based upon the fact that metallic copper will precipitate gold and silver upoil its surface from acid solutions. Of course, the fact is not new, but its application is probably so. I have used the method with success; it recommends itself by the rapidity and ease with which it may be carried on. An auriferous cyanide solution, if made acid with sulphuric acid and boiled with finely divided, pulverulent, metallic copper, will, within a short time, deposit its gold-content on the copper. Any silver in the solution is also precipitated. If this mixture is now filtered, the filter and contents may at once be subjected to a crucible assay treatment, and its lead buttons cupelled and determined. If, instead of taking cement-copper, or any metallic copperpowder, a solution of bluestone is used after acidification, and a few small pieces of sheet aluminum are added, and the solution boiled until all the copper has come down, the result as to the precipitation of gold and silver is the same. This modification takes more time and attention in boiling. If aluminum has been used, it should go into the crucible with the filter and

Jan 1, 1904

By R. J. Robbins

"For his exceptional ability both as an engineer and entrepreneur in the conception, design, and marketing of underground boring equipment; a technological development which has greatly improved the efficiency and safety of underground mining." Recipient of the 1984 D.C. Jackling Award

Jan 1, 1985

By William E. Bruce

This paper is intended to provide an improved understanding of natural draft (natural ventilating pressure) and the effect of natural draft on underground mine ventilation circuits. Attention is focused on measurement of natural draft pressures during ventilation surveys in mechanically ventilated mines and on different methods for modeling natural draft using the measured data. A number of examples are presented which utilize data collected during absolute air pressure surveys made by personnel of the Ventilation Division of the Mine Safety and Health Administration's Safety and Health Technology Center, Denver, Colorado. Examples are used to illustrate how the data from absolute air pressure surveys may be interpreted to determine whether natural draft pressure is present and what its magnitude is. In addition, two different methods are described for mathematically estimating the magnitude of the natural draft pressure. Comparisons are made of results obtained using the different methods. Different procedures are described for modeling natural draft using the MSHA-modified Penn State computer program. Use of the routines is described and illustrated relative to drafts that aid or oppose the mechanical ventilation system. Tabulations of results facilitate comparison of outcomes obtained using the different modeling procedures.

Jan 1, 1982

By Maximo Monte-Flores

A PERUSAL of the most recent literature on the subject of hydrocarbons reveals that one point seems, to have been neglected by the various theories; that is, the influence of the bed-rock on the accumulation and distribution of oil and gas. This can be seen from the following statement of the principles of the most accepted theories. ANTICLINAL THEORY The anticlinal theory claims that the accumulation of the hydro-carbons in deposits of commercial importance was brought about by the gravity of the hydrocarbons, the oil and gas being forced to the top of the porous stratum by the difference of the specific gravity of the hydro-carbons and the water. The principal factors toward the accumulation were the general stratigraphic condition of the rocks, their texture and porosity, and their water content. This theory advocated the preexistence of structural deformation as the basis of the motion of gravity, thus implying the principle that the forces that have caused the deformation have had no influence on the movement of the hydrocarbons. STRUCTURAL THEORY According to the structural theory, the accumulation is due, chiefly, to the structure of the subsurface rocks and differs from the anticlinal theory, mainly, in not considering that the motion of the liquids have been caused by the force of gravity.

Jan 1, 1920

By Samuel Taylor

IF I LIVE another fourteen months and am still con-nected with the coal industry, I shall then have com-pleted a half century with it. Since May, 1874, when .I first entered the bituminous workings as a miner, I think I have held almost every position connected with a mine except possibly that of mule driver, for which I was unfitted by reason of my religious upbringing. We are all agreed, at least I have not heard it contra-dicted, that there is serious over-production in the bituminous industry. This has come about in various ways and is easily explained. During the Fuel Admin-istration, I recall making an estimate of the possible output of the bituminous mines of the country provided they were given a full force of men and a full-car supply; my estimate was a little over a billion tons a year. A few months ago, the late Francis H. Peabody, of Chicago, made a practically identical estimate. If, however, both of these conditions should happen con-currently, there would very soon be no market for the coal, and many of the mines would close down. Even today, if 10 per cent. more cars were furnished, to the bituminous mines, market prices would drop very seriously.

Jan 4, 1923

By Sherwin F. Kelly

GEOPHYSICS may be considered a vice (albeit, I submit, a comparatively harmless one) whose career is aptly described by Pope's lines: Vice is a monster of so frightful mien, As to be hated needs but to be seen; Yet too oft, familiar with her face, We first endure, then pity, then embrace. Although there may be some that have not yet succeeded in emancipating themselves from the first stage of horrified contemplation, geophysicists may be duly thankful that there are mining men and geologists that have arrived at a state of apparently irretrievable damnation.

Jan 1, 1936

By Zárate G. E.

Practical and statistical considerations concerned with the sampling, sample preparation and chemical analysis of precious metal ores are reviewed. The principal requirements related with the characteristics of sample cutter, sample preparation, equipment and methods are discussed. The main errors introduced in the different stages of the sampling systems are defined. The application of statistical techniques to evaluate these errors to determine the ore grade variation and to design the number of increments needed to get an accurate assay are presented. Finally, results obtained with the application of this method to gold and silver ores are analyzed and some recommendations are given.

Jan 1, 1984

By M. A. Mahtab, T. M. Yegulalp

This paper presents the development and application of an approach for clustering fracture orientation data. Data are projected on the surface of the unit upper hemisphere and the clustering approach is applied in three steps: (1) randomness test and identification of dense clusters, (2) estimation of cluster statistics, using Bingham distribution, and (3) rejection of extremal data based on Chauvenet's criterion.

Jan 1, 1982

By Benjamin C. Craft

Operations on the Louisiana Gulf Coast during 1936 resulted in the discovery of five new fields and the proving of flank production or new sands on 12 of the older fields. This district gained the rank as the outstanding deep-drilling region of the world. At the close of the year. 10 wells had been drilled beyond 10.000 ft. One of the most important

Jan 1, 1937