Search Documents

By R. O. Neal

There are two main sources of the water that floods productive oil or gas sands. The water may rise from the lower depths of the producing stratum, or it may come from beds above or below the oil-bearing formation. Usually the recovery of oil is decreased by water entering the oil sands, and most oil-field waters, especially those of deep wells, tend to foster the formation of an emulsion, which is expensive to treat. This paper deals with a method of distinguishing between waters that encroach upon oil-bearing beds from sources in the same stratum and waters that reach the oil sands from horizons above. In order to remedy effectually water difficulties in oil and gas wells, it is absolutely necessary to determine the source of the invading water. Sometimes evidence such as the structural relations between the strata penetrated by deighboring wells and those found in the well under investigation is not adequate; also, data from drill logs and well records, from mechanical tests made on the wells by plugs, testers, drilling tools, etc., and from tests by chemical indicators such as eosin and Venetian red, may be unsatisfactory, for such data may fail to locate the source of the infiltrating waters. As a resort in such cases, the application of chemical analyses, that is, the comparison of an analysis of the water in question with that of typical waters from the various water horizons in that particular district, has in certain instances proved of value. This method has been used to advantage in the Westside Coalinga field of California, where the source of water may be fairly definitely determined , from its composition. The chief conclusions concerning the chemistry of the oil-field waters in California by G. S. Rogers1 are: "Oil-field water is not necessarily salty, as is generally believed, and may not be even slightly salty to the taste. The degree of concentration of chloride in such water is governed primarily by local conditions and is not affected by the position of the water in relation to oil. Sulfate diminishes in amount as the

Jan 1, 1920

By H. C. Miller

THE gas-lift method of flowing oil from wells is the outstanding feature of petroleum technology today. Its forerunner, the air lift, was used successfully first, in the Baku fields of Russia, in 1899, and later in the Gulf Coast fields of Texas and Louisiana and the Kern River field of California. It is still used to a limited extent in certain oil fields. The use of compressed natural gas for lifting oil from wells has supplanted the air-lift method in a measure in those fields where a sufficient quantity of gas accompanies the oil to make the gas lift possible, or where natural gas is plentiful and inexpensive. We find therefore in California, that, natural gas is used at practically every well where a gaseous medium is employed to flow the oil. The use of natural gas has many advantages over that of air. It is possible to recover and save the gasoline from the gas that accompanied the oil to the surface. This gasoline would be wasted if air were used as the lifting medium. Also, certain proportions of air and gas form an explosive mixture that cannot be handled safely by compressors. Another advantage that gas has over air is that gas under pressure is more soluble in oil. Gas in solution in oil reduces the viscosity of the oil that is being produced and causes it to flow more readily through the. tubing and flow lines. The gas lift has made it possible to recover many thousands of barrels of oil from deep wells in California that could not have been produced otherwise. It would not have been economical, had it been mechanically possible to produce such wells as the world's deepest producing oil well (Miley Athen's No. 6, Rosecranz field, California) by any other method of pumping known today. At this well, production is obtained from between 7305 and 7591 ft. and 11 months after completion of the well, production was being maintained on the gas lift it approximately 2000 bbl. a month. The crookedness of the hole, or its diameter and depth will not prevent the successful application of gas-lift pumping when other conditions are favorable.

Jan 1, 1927

By P. H. Cardwell

The effect of various plastics upon the permeability of a sand and the mechanism of their ensuring permeability within the consolidated sand body is discussed. Data are presented on various properties of the plastic materials used in sand consolidation and the effect of temperature and usable temperature ranges are considered. The recovery of petroleum from uncon-solidated sands presents serious production problems, owing to sloughing of the formation. The solution of some of these problems usually has been by mechanical methods.' The ideal way of controlling the sloughing tendencies of these un consolidated formations, however, is to prevent the movement of the individual sand grains by the use of a bonding medium. A step in the desired direction was taken by Irons and Stcesser2 when they taught the use of liquid plastics to produce a consolidating deposit that prevents sloughing. More recently, Wrightsman and Buckley3 proposed a modification of this process. In this use of the liquid plastic, the sand grains become coated and the ensuing hardening of the plastic by polymerization or condensation cements together the sand Particles. Liquid plastics that have been suggested for this Purpose are of the following types: phenolformaldehyde, alkyd resins, vinyl type resins, polystyrene and the acrylic esters. When the flow of fluids through a sand must not be materially reduced, it is essential only to cement together the sand grains with liquid plastic and leave a portion of the interstitial space for fluid flow. TO be assured of obtaining fluid flow through the sand interstices after injection of plastic, it has been necessary in the past to remove the excess plastic from the interstices between the particles before it sets. Wrightsman and Buckley suggest two methods for the removal of the excess plastic from the interstices of the sand: (I) to flush the excess plastic back into the formation, away from the well bore, by use of oil or water; (2) to produce the well before the plastic has set, thereby moving the excess plastic into the well bore. Under certain well conditions it is very difficult to remove the excess plastic from all parts of the formation by either of these methods and leave the formation consolidated with no sections completely sealed. The method* described herein of retaining permeability within a sand body is to use a liquid plastic that upon setting ensures permeability within the consolidated sand body. This cements the sand grains but obviates the need for removing plastic from the interstices of the sand. One of the ways of accomplishing this is to use a liquid plastic that occupies a considerably greater volume than the solidified resin it yields on further polymerization or condensation in situ. In order to be satisfactory, the volume of the plastic while liquid should be at least one and one half times the volume of the solid formed. Preferably,

Jan 1, 1947

By Philip W. Simmons

THE Colorado Plateau uranium province is in a mining boom rivaling the most colorful days of the early West. The application of scientific skills and the use of modern and novel mechanical equipment, however, is unique. No metal has ever received such concentrated effort from geologists and mining engineers. Moreover, no other metal has had the variety of tools available for finding and mining ores. Radiation detection equipment, bull- dozers, truck-mounted wagon and core drills, jeeps, airplanes, helicopters, tractor loaders, self -propelled 3-wheeled dump cars, front-end loaders and fleets of modern trucks are some of the present-day tools of the uranium prospector and miner. Because uranium is so vital to our national defense, the Atomic Energy Commission has offered many incentives for its mining. Through a series of circulars, the AEC has established base price schedules and various incentive payments. The incentive payments for acceptable ores from domestic mines are: (1) a guaranteed base price of $3.50 per Ib for ores assaying 0.20 pct U3O8 and more; (2) premiums based on grades above 0.20 pct U3O8 as for example, ores assaying above 0.50 pct U3O8 receive $1.00 per lb premium; (3) a development allowance of 506 per Ib of U3O8 contained in ores assaying over 0.10 pct U3O8 (4) an ore haulage allowance of 64 a ton mile for a maximum of 100 miles; and (5) an initial production bonus which may amount to as much as $35,000 in addition to all other payments. The producers have been guaranteed this policy until Feb. 28, 1957. The other four will continue until April 1962.

Jan 4, 1954

By Persifor Frazer

THE following notes on the Whopper and adjoining mines in the Gunnison district of Colorado were made in the spring of this year. The time chosen for the author to visit the region was, unfortunately, the most unfavorable of an exceptionably unfavorable year. About the middle of May all the hill slopes, which at this period of the year are generally covered with pasture, were thickly covered with snow. The unusually large precipitation of this year caused local mountain torrents at every few hundred feet, which wore away the soft foothills into gulches, gouged great chasms out of the roads, and transformed miles of usually dry soil into dangerous quagmires. Travel was totally interrupted for weeks, except on horseback or afoot, and even then with great difficulty and some danger. The Whopper mine is situated on the Whopper Mountain, about two miles from the headwaters of Rock Creek, and on the right bank of that stream. The Whopper Creek flows into Rock Creek from the east, and, by a precipitous descent, offers excellent facilities for its utilization as a source of power. This stream, which pours past the picturesque Whopper Cabin .about thirty tons of water a minute, has a fall of 100 feet in 400 yards, and is said to be a stream of some size, even at the seasons of the year when-drought prevails. The Whopper claim extends down the bill a distance of about 250 feet to its intersection with the Whopper Creek (on the other side of which is a small tunnel on its extension called the "Teller ") and over the steep hill northwest to the limits of the claim about 1250 feet. The part of the mountain in which this mine is situated is remarkable for its splendid forest, the spruce, fir, and quaking asp covering the mountain-sides with a green growth of valuable timber. The distance from Gothic City to this mine is about eight miles along the valleys of East River and Rock Creek, and on the divide which separates them. The elevation of Gothic City is given from the engineer's notes as 9500 feet above sea-level, and the mean of several observations with a Beck watch-barometer made the elevation of Whopper Cabin (which is about fifteen feet above the floor of the Whopper upper tunnel) about 1250 feet above Skiles's Cabin in Gothic City. The record of this instrument must, how-

Jan 1, 1881

By T. Sterry Hunt

BUT little was known of the coals of Southeastern Ohio until the present survey of the State under Dr. Newberry began its work. The results of the geological investigations of Prof. E. B. Andrews in this region, and of the chemical investigations of Prof. T. G. Wormley, both of which appear in the reports of the survey for 1869 and 1874, and more recent special reports by the former, together with some data for which I am indebted to the kindness of Dr. Newberry, and my own limited observations, have served me for the preparation of the following notice of the coals lying on the western border of the great Appalachian coal-basin in the region drained by the Hocking River and its tributaries, and belonging to the Lower Coal-Measures. Some uncertainty exists as to the place in the succession of the lower coals to be assigned to the seams known and mined in the Hocking Valley. It is the opinion of Prof. Andrews that the inequalities of the original surface were such that we cannot identify in that region the lowest coals known in Northwestern Pennsylvania and the contiguous parts of Ohio, but that we must rather count from above downwards. These conclusions Dr. Newberry is not prepared to accept, and further researches will be necessary before certainty can be attained in this matter. Meanwhile it seems, from a study of its relations to the Pomeroy or Pittsburgh seam, that what is known as the great vein of the Hocking Valley, occupies the horizon of the Upper Freeport coal, E of the Pennsylvania survey, or No. 6 in Dr. Newberry's enumeration, counting from the base. This seam, in the region in question. assumes certain characteristics which, taken in connection with its geographical position, give it a great importance among the coals of the State. The area to be noticed includes the whole or parts of several townships in Perry, Hocking, Vinton, and Athens Counties, lying near the margin of the basin over which the vein in question assumes the character of a dry-burning or splint coal, and has a thickness varying from six to ten and even twelve feet. Its precise limit southward cannot at present be clearly defined, but it has been found as far south as the line of the Marietta and Cincinnati Railroad, with a thickness of six feet, and is mined at various points along the valley of the Hocking River, near Nelsonville, where it attains six or seven feet. To the northward, along the tributaries of this river, Sunday and Monday

Jan 1, 1874

By David R. Mitchell, R. B. Hewes

MANY processes for cleaning coal that are in use depend primarily on physical properties of coal and refuse other than specific gravity and surface conditions relating to froth flotation. These properties are shape, coefficient of sliding friction, resilience, friability, magnetic susceptibility, and electrical conductivity. In many of these processes specific gravity does have some effect and many separators are designed to utilize more than one of the physical properties cited. Although the processes described herein do not have a widespread application, yet for specific coals and specific conditions, they are economically important. A problem confronting many coal-mining districts is the marketing of the slacks or screenings and dust passing the final sizing screens. Processes in commercial use installed primarily to increase the form value, and hence the market value, of these slacks and dusts include briquetting, packaging, and low-temperature carbonization. MECHANICAL PICKERS Machines utilizing shape, frictional resistance, and differences in resilience of coal and impurities are usually called mechanical pickers. They require a closely sized feed, therefore their use is confined to the pea, nut, and egg sizes. Various types of these devices are described by Berrisford, 1, 2 Taggart,3 and Peele.4 Shape In general, coal differs in shape from its accompanying dirt throughout the range of commercial sizes. Coal, breaking into roughly cubical particles, contains a greater number of axes that are approximately the same length than does the dirt. The latter, consisting of pieces of slate and shale and lenses of pyrite, is flatter in nature. Further, flat coal often has a dirty, slaty appearance, even though of high quality. Mechanical pickers known as flat pickers, or "flatters," are widely used in the Pennsylvania anthracite region to remove flat coal .from the final clean coal. This practice greatly improves the appearance of the final market product. Flat pickers for removing impurities or flat coal ("flats") are usually installed on shaker screens, shaking conveyors, and chutes. In Fig. 1 three

Jan 1, 1950

By Brahm Prakash, R. Schuhmann

Chemical conditions for flotation and nonflotation of cassiterite and fluorite with oleic acid as collector and with alizarin dyes as modifying agents were studied by means of small-scale, vacuum-flotation tests. Artificial cassiterite was prepared fot these tests by high-temperature methods, especially by crystallization from borax melts. FLOTATION test work on Bolivian tin ores some years ago led to the development of several workable schemes of selective soap flotation, but left unanswered many questions of soap-flotation chemistry.' Accordingly, the study of the activation and soap flotation of quartz just reported? was undertaken as a start toward the elucidation of some of the unanswered questions. The experimental work on quartz flotation consisted primarily of small-scale, vacuum-flotation tests in which activator and collector additions and pH were varied between wide limits. In the work to be described in this paper, the soap flotation of cassiterite and fluorite was studied by the vacuum-flotation technique developed in the previous study of quartz. Using oleic acid as collector, conditions for floating cassiterite and fluorite in the absence of modifying agents were first determined. Then the effects of barium, calcium, and alizarin dyes on the flotation of cassiterite, fluorite, and quartz were studied. Alizarin dyes were chosen for study because of the promise they have shown as selective modifying agents in the flotation of non-sulphide minerals.12,1 Also, they form a family of reagents in which there should be a systematic correlation of chemical properties with composition. As a preliminary to the study of cassiterite flotation, an investigation of the preparation of synthetic cassiterite and X ray studies of natural and synthetic cassiterite were undertaken. Experimental Methods The flotation technique and most of the reagent preparations were described fully in the previous paper.' In addition, for the present work it was necessary to prepare satisfactory stocks of clean cassiterite and fluorite and to obtain samples of alizarin dyes. Cassiterite: High-grade cassiterite from the Netherlands East Indies was crushed, sized, and cleaned

Jan 1, 1951

By B. L. Averbach

THE rolling process may be considered as a case of a nonhomogeneous plastic flow. In such a heterogeneous deformation there is no direct general solution, and the plastic deformation varies from point to point as a function of the coordinates. It is practicable to determine these plastic strains only at the conclusion of the rolling process, and the local strains can be studied by observing the deformations produced in a suitably placed grid system. Strains at the surface of a bar after rolling have been reported by MacGregor and Coffin,' but the strain distributions within the bar have not been previously observed. Siebel² has investigated the plastic deformations resulting from wire-drawing by splitting the wire along its axis, milling a grid coordinate system on the inner plane surfaces, and binding the .wire together so that it would pull through a die as a single unit. This method was possible because of the rotational symmetry of the die. In the rolling process, however, such a system was not readily applicable. This paper describes another method of including a grid system, and reports some preliminary data on the plastic rolling strains within a square bar. Experimental Procedure 2.1 mm wide (144 network squares per sq in.) was punched from a thin lead sheet with a steel die and supported in a brass mold by thin copper wires. Pure tin was then poured around the grid to form a solid bar, with the network securely imbedded at. a given position. This bar was then machined to a square 15.2 mm (0.60 in.) wide, and then radiographed. The lead grid was quite adherent and sufficiently ductile to follow the deformation of the bar faithfully. The network lines also remained sharp enough to maintain a high radiographic contrast, and the tin bar, with the grid included, could withstand considerable deformation at room temperature without splitting at the interface. In order to fill the mold, it was necessary to cast the tin at 260-280°C and during pouring the lead grid was supported at short intervals to prevent warping. Some shrinkage cavities were encountered, but only bars which were free of shrinkage in the network region were used. This method is similar to the one employed by Steinberg" in an investigation of the strain distribution in a tensile specimen. Before rolling, the machined bars were radiographed in two directions to obtain accurate initial dimensions of each square and to observe whether the grid was straight and correctly positioned. The rolling was performed in a small hand mill with 2 in. diam rolls at room temperature, and a 20 pct reduction based on the original height was employed. The rolls were clean and no lubricant was used. Halfway through the bar, at the center of the network, the rolls were reversed and the bar extracted. These bars were then radiographed again

Jan 1, 1951

By Grover J. Holt

IN order to provide a clear picture of the development of the sink-and-float process of concentration as applied to the iron ores of Minnesota, a few pertinent facts should be brought out concerning the ores and the products of concentration. Iron ore is primarily a cheap commodity handled in immense quantities. The price of iron ore at present, based on a natural iron content of 51.5 per cent, varies from $2.55 to $2.70 per gross ton f.o.b. cars at the mine or washing plant in Minnesota. Last year 92,000,000 gross tons were shipped from the Lake Superior district (Minnesota, Michigan, and Wisconsin) to the furnaces. Concentrated iron ores have no greater value per unit of iron content than ores that can be mined and shipped direct from the shafts or open pits. For years only the higher grades of concentrating ores could be treated and sold in competition with the immense reserves of direct shipping ore available. These higher-grade "straight wash" ores required only the simplest treatment; namely, the washing out of fine sand from coarse ore particles. As the exhaustion of the "straight wash" ore is reached, rock is found replacing part of this sand, and the ore no longer responds to the former sizing treatment. Substantial tonnages of this marginal (jig ore) remained to be treated. Because of the limitations placed on concentrates by the furnaces-namely, low price of product and minimum amount of fines-iron-ore concentration has been and must continue to be a one-pass process. Only an increase in price or a change in structure of concentrates allowed by the ore consumer will encourage departure from this practice. Faced with the necessity of handling large tonnages, with the limitations mentioned, iron-ore research men have found their search for new and more efficient methods of treatment seriously handicapped and removed from the field of fine crushing. Sink-and-float treatment appeared to offer the best field in coarse concentration and has been proved by several plants to be well adapted to our problem. The use of ferrosilicon as a medium solid was decided upon. In our present practice, the ferrosilicon metal, carrying about 83 per cent iron, 15 per cent silicon and 2 per cent carbon and nonmagnetics, is crushed to pass 65 mesh and used without further sizing. When mixed with water the specific gravity of the medium may be controlled to within 0.02 per cent above or below the required gravity. Table I shows examples of a change in solid content of the medium for varying gravities. [ ] Table I is based on clean ferrosilicon, whereas some contamination is always present in the mill circuit, tending to

Jan 1, 1943

By J. F. Wilson

Steady-state flow theory, previously applied to displacements with two mobile phases, is extended to cover down-structure flow involving three mobile phases: oil, gas and water. When used with normal reservoir fluid properties, the theory predicts the existence of four distinct flow regimes and the conditions under which each regime exists. The predicted behavior is verified by a parallel-plate model study. INTRODUCTION Special problems exist when a water flood is contemplated in a dipping reservoir having a substantial gas cap. Normally, the gas-cap region is one of very low oil saturation. If oil is moved into the gas cap during the flood, a loss in recovery results. Efficient recovery of the oil underlying the gas is therefore difficult. In two reported field water floods, injection into the gas cap has been used to solve these problems. At the West Norfolk Garr Sand Unit, injection into the upstructure region of the reservoir was made for the stated purpose of filling up the gas cap with water.' The purpose in the Sholem Alechem Fault Block "A" Sims Sand Unit was to form a continuous water barrier between the gas cap and oil band.' A laboratory model study preceded this flood and was described in the same publication. Both of these gas-cap water injections gave satisfactory results, but the published data are insufficient to allow generalizing to other field conditions. The present investigation was also undertaken to obtain results for a specific field problem. However, these results will be shown to be in agreement with an extension of the Dietz3-5 mathematical model to three-phase flowing systems. The agreement between the theory and the model studies indicates that the mathematical model can be used to describe completely the flowing system under some conditions, and to indicate the general type of flow to be expected under all conditions. FLOW THEORY The Dietz equations for two-phase flow are derived "' for the case of constant-velocity linear flow in a homog- eneous porous medium. The transition zone between the fluids is assumed to be of negligible extent so that the displaced and displacing fluids are separated by a sharply defined interface, as illustrated in Fig. 1. The density and mobility of the displacing fluid are constant over the region behind the interface, and the same properties of the displaced fluid are constant over the region ahead of the interface. To extend the Dietz equations to three-phase systems, we postulate the flowing system shown in Fig. 2 and determine the conditions under which it can exist. The

By Albert Sauveur

Floris Osmond, Honorary Member of the American Institute of Mining Engineers, born in Paris, March 10, 1849, died at Saint-Leu near that city, June 18, 1912. Taken suddenly ill with congestion of the brain while on his way from Paris to his home, he reached it in time to write on the typewriter his last wishes, one of which was that no biographical notice of his life should be published. Holding Osmond's memory sacred, as those who have known him will, is it our duty to conform with his desire ? Shall no mention be made in our Transactions of the beautiful life and great achievements of one of our most honored members? Is it not, on the contrary, incumbent upon us to disregard Osmond's instruction in this matter and to place on record our admiration for the nobility of his life, for his talents and for the importance of his work, that younger men may be inspired by it with a desire to be guided by worthy motives in the path of unselfish pursuits ? I cannot feel that in following this course I am disloyal to Osmond's memory and I am strengthened in this belief by the opinion of men of high honor whom I have consulted before undertaking the writing of this obituary notice. One of them, Professor Henry M. Howe, justifies my decision better than I could do it myself when he writes : " Let us look frankly at the matter. Here we have a most extraordinary life, a life of rare beauty and power of inspiration to the rest of mankind. In my opinion we should not deprive mankind of the stimulating influence of the example of M. Osmond simply because he shrank from publicity. Our young men see every day how greed and vulgar push succeed, and with what material rewards they are crowned. They see too rarely the more valuable crown which comes to self devotion. A permanent and public recognition of the beautiful qualities of Osmond's life cannot fail to appeal to the imagination of young men and to help to deflect them toward leading a noble rather than a sordid life. Therefore I feel that the Revue de Métallurgie and other bodies owe it to the public to give prominence to his career by means of biographical notices."

Jan 1, 1914

By L. Sturkey

Quantitative X-ray diffraction studies of the precipitation of thorium in a Mg + 3.3 Th + 0.51 Zr alloy (HK31A) in both the as-cast and cold-worked states show that the precipitation may be described by f = 1 - e(t/T)1/2 over most of the aging period. The effects of cold work and temperature changes are determined. The precipitation of tile equilibrium Mg-Th compotund is Preceded by the formation of a transition phase of higher thorium content, with the cowposition Mg2Th and with a Laves-phase structure. Thorium-containing alloys of magnesium have assumed considerable commercial importance, especially for applications requiring exposures to temperatures greater than 500°F for appreciable lengths of time. The principal commercial wrought alloys in this system are HK31A, containing nominally 3 pet by weight thorium and about 0.7 pet by weight zirconium: and HM21A. containing 2 pet by weight thorium and 1 pet by weight manganese. These two alloys retain a high level of properties even after exposures of 100 hr at 600°F, while the more common alloys containing aluminum and zinc are badly overaged by these conditions. Therefore, in order to obtain some insight into the mechanism by which thorium produces high temperature stability in these wrought alloys, it seems desirable to investi- gate the effect of temperature and mechanical working on the precipitation processes involving thorium. Since the scattering power of a thorium atom for CuKa X-ray radiation is about ten times that for a magnesium atom, the magnesium alloys containing about 3 pet by weight thorium are ideal for quantitative measurements by X-ray diffraction of the amount of Mg-Th compound present at any time. Such quantitative measurements should be of theoretical importance in the study of the effects of time, temperature, and deformation on precipitation and precipitation hardening. Of the two commercial alloys, HM21A and HK31A, the latter is certainly the most suitable for study: In the Mg-Th-Zr2 system, only Mg-Th compounds need be considered, since no ternary compounds or binary Th-Zr3 and Mg-Zr4 compounds exist. The Zr is added to this alloy as a grain refining agent and probably plays a secondary role in precipitation. On the other hand. thorium and manganese form many

Jan 1, 1961

By Warren E. Wilson

The transportation of solids in pipe lines is a matter of deep concern in many fields of engineering. Much experimental and theoretical work has been done in an effort to devise means of designing pipe lines that will satisfactorily transport given solid loads, but there remain many unanswered questions in this field. The present discussion will be confined to a rather narrow portion of this field and will endeavor to point out certain factors that may well be considered when comparing the relative economy of various installations. The data have been presented previously but a new interpretation was prompted by a suggestion in a paper by Professor O'Brien,1 of the University of California, that the friction work per pound of dry material should be considered in determining the relative efficiency of various installations. This method of considering relative economy in various pipe lines leads to some rather unexpected conclusions, especially with reference to the economy of large pipe sizes. A previous suggestion by the writer3 concerning the economy of a rather peculiar type of installation is strengthened. It is not believed that the considerations set forth herein apply directly in the case of dredge lines, where economy is largely a matter of a high rate of pumping in order to reduce the unit overhead charge. However, it is believed that some value may be gained from these considerations in cases involving the disposal of a fixed amount of solids per unit time with a minimum expenditure of energy and at a low cost for replacement of worn pipes. Such situations are not uncommon in the disposal of mill tailings and the disposal of solids deposited from irrigation waters. It was found that data leading to general conclusions for various pipe sizes were not available but certain definite trends are indicated and methods of analyzing available data are presented in the hope that they may be of assistance in preparing engineering estimates on designs of pipe lines of the type described above. Energy Requirements Carrying out the idea contained in ' Professor O'Brien's paper concerning the method of computing energy required to transport solids, the following analysis leads to some rather interesting conclusions. Let us represent: Solids load in term of mass per unit time by W Ratio of mass of suspended solids to total mass of mixture flowing by p Volume rate of flow of mixture by Q Length of pipe by L slope of energy grade line by s Mass per unit volume of solids by m. Mass Per unit volume of liquid by mi Mass per unit volume of mixture by mm We then have as an expression for the solids load: W = pQmm The work done per unit mass, P, on the mixture to move it along the pipe the

Jan 1, 1948

By C. A. Mitke

(Butte Meeting, August, 1913.) 1. Character of Gases which Caused Helmets to Get Out of Order. DURING September, -1911, the fire area in the Lowell mine continually increased and gases resulting from the fire came through the upcast shaft. These gases contained such a large percentage of sulphur dioxide that the men were unable to go up and down on cages, and, within a comparatively short time, repairs in the shaft were found to be necessary. Since the fire was in sulphide ores and extended into certain timbered sections, the gases contained varying amounts of SO2 CO2, and perhaps, at times, CO. The temperature in the shaft was generally about 97°, and the relative humidity from 97 to 99.5 per cent. The corrosive action of the fumes became apparent when the cables had to be changed more often than usual, the heads of lag screws .in the guides of the shaft disappeared, and the cages needed frequent repairs. It also became necessary to repair two compartments of the shaft by putting in 150 ft. of new guides between the 600 and 800 levels and lag screws in nearly all the old guides from the surface to the 800 level. 2. Ordinary Methods of Testing Helmets which were Unsatisfactory. These conditions required all work to be done by men wearing oxygen helmets. The Draeger type was tried, and was used until all repairs were completed. At first the helmets were. tested for air circulation and air tightness and the injector was tested by water gauge according to the methods recommended by the Draeger Oxygen Apparatus Co. Six arrangements, covering .these different tests, are illustrated in the catalogue and circulars of the company.

Jan 7, 1913

THE 127th meeting of the Institute was held in New York, Feb. 19 to 22, 1923. In addition to the usual large volume of technical matters under consideration, the meeting was particularly noteworthy for the amount of attention given to its business session; the convention of local section representatives also was full of interest. The total registration was 1201. The annual business meeting on Feb. 20, President Dwight presiding, was attended by 125 members, who listened with marked attention to the reports and addresses of the several officers. The chairman departed from the stipulated order of business in order to allow more time for the presentation of remarks on the state of Institute affairs. The previously pub-lished reports of the officers were accepted, as printed. On the report of the tellers, the following officers were declared elected: E. P. Mathewson, Director and President-District 0 T. T. Brewster, Director and Vice-president-District 6 Frank M. Smith, Director and Vice-president-District 11 W. H. Aldridge, Director-District 0 G. H. Clevenger, Director-District 1 A. N. Diehl, Director-District 3 Reno H. Sales, Director-District 7 Seeley W. Mudd, Director-District 10

Jan 3, 1923

By Lester Uren

The fluid level maintained in wells pumped for oil is an important factor in deter-mining their productivity but one that has received little attention in the literature relating to petroleum-production technology. In the present paper the writer undertakes to show how and to what extent fluid level influences productivity and suggests the use of a fluid level indicator as an aid to the oil producer in maintaining the fluid surface within the well at the proper position. IT is realized that the depth of fluid maintained in a pumping well is sometimes influenced by other considerations than the quantity of fluid that will enter the well: the prevention of sand incursion, prevention of waste of natural gas, and the maintenance of a suitable submergence for the pump, for example. These latter factors have an important influence on the productivity of the well, so that otherwise unwarranted fluid levels must sometimes be maintained to offset them; but where the handling of unconsolidated sands is not a problem of consequence and where water has been properly excluded, the principles developed here and the practices recommended, should apply. The principal objective of the producer should be to produce the maximum quantity of oil in the shortest possible time. Any method or equipment that will increase the rate of production during the early years of the life of the well, when gas pressure is high, will greatly augment the .ultimate production. The maintenance of a proper fluid level in the well at all times will go far toward accomplishing this desired result. For a given set of conditions surrounding the flow of oil into a particular well, in which the viscosity of the oil, the porosity and grain size, of the sand, and the diameter of the well appear as constants, two variables determine the quantity of oil that will flow from the sand into the well. These are: the effective pressure behind or within the oil in the reservoir sand, and the fluid level maintained within the well.. The former is the expulsive force that causes movement of oil from the sand into the well, while the latter determines the magnitude of a resisting force opposing such movement. The first of these factors is largely beyond the control of the oil producer, but it is in his interest to reduce the opposing force to the lowest economic limit.

Jan 2, 1925

By Morris Muskat

TEe method of R. W. Moore' for determining subsurface interfacial depths by means of integrated curves of apparent resistivity has been analyzed theoretically. It is found that the only unique tangents that can be drawn to such curves are the asymptotes at infinite electrode spacing and the tangents through the origin at vanishing electrode spacing. Explicit expressions have been derived for the relationship between the electrode spacing at the points of intersection of these tangents and the thickness of the surface strata as a function of the conductivity parameters for the two-layer and three-layer earths. It is found that in all cases the electrode spacing at the points of intersection will exceed % of the thickness of the surface layer, and may even become indefinitely large as the resistivity of the deepest layers increases as compared with that of the surface layer. These results do not agree with the empirical findings of Moore that the intersection of the tangent lines fall at an electrode spacing very approxirnately equal to the thickness of the surface layer. Introduction In a recent paper, R. W. Moore1 proposed a new method for the analysis and interpretation of earth-resistivity measurements. This consists essentially in plotting against the electrode separation of a Gish-Rooney system the integral of the apparent resistivity with respect to the electrode spacing, and observing the breaks in the integral curves. Specifically, tangents are drawn to the various segments of the integral curves, which show appreciably different slopes, and the intersections of these tangents are used as indications of the depths of the various underlying strata. By numerous examples Moore has shown that the electrode separation at the first intersection so found agrees very closely with the depth of the bottom of the surface layer. Moreover, in a number of instances the intersections for greater electrode spacings seemed to correspond to the depths of deeper beds. From a strictly empirical point of view, the procedure proposed and demonstrated by Moore appears to be particularly interesting because of its simplicity as well as its apparent accuracy, Moreover, such a simple method would be especially valuable in view of the well-known difliculties heretofore encountered in the quantitative interpretation of resistivity data. It therefore seems appropriate to attempt a mathematical analysis of the problem to see whether the integral method of Moore has a sound basis. Such an analysis is presented here. Even on cursory consideration, it is clear that the remarkable successes observed by Moore in the application of his method are indeed surprising. For it depends upon the determination and choice of the slopes of smooth and continuous curves, which by their nature must show even more gradual- variations than the original apparent-resistivity plots that are already so difficult to interpret quantitatively. It is well established, of course,

Jan 1, 1946

By A. L. Holley

THE application of scientific methods to the investigation of natural laws and to the conduct of the useful arts which are founded upon them, is year by year mitigating the asperity and enlarging the outcome of human endeavor. More notably, perhaps, are these the facts in that system of productive and constructive arts of, which engineering is the general name. In metallurgical engineering especially, within the period of our own recollection, how rapid has been the rate and how wide the scope of progress: the scientific discovery and mining of metalliferous veins; the economical separation and reduction of ores of every grade; the production and regulation of high temperatures; the varied improvements in the manufacture of iron, in saved heat and work, in uniformity and range of products ; and, most important of all, the creation and the utilization, to be counted by the million tons a year, of the cheap constructive steels. Wonderful as this range and degree of development may appear to the public eye, the close and thoughtful observer must, nevertheless, conclude that neither the profession nor the craft of engineering may congratulate themselves too complaisantly, but that they should rather acknowledge to each other the embarrassing incompleteness of the union between engineering science and art. There is a small school of philosophers whom we may designate as original investigators, men who come close to nature, who search into first principles, and who follow that scientific and therefore fruitful method by which the relations of matter and force are discovered, classified, and brought within the reach of practice. These wonderful - men do not indeed create the laws of nature, as they sometimes almost seem to, but they go up into the trembling mountain and the thick darkness and bring down the tables upon which they are written. * President's Opening Address. The discussion following this paper, and also the Joint Discussion of the Institute and the American Society of Civil Engineers, on the subject of Technical Education., are published in a separate volume.

Jan 1, 1876

By W. F. Hosford

A quantitative explanation is offered for the peculiar curled grain shapes found in the microstructures of drawn wires of bcc metals and compressed aluminum specimens. It is shown that once an [011] fiber texture is developed, the slip system are so oriented that further slip tends to produce plane strain rather than axially symmetric flow of individual grains. With plane -strain flow, however, compatibility of neighboring grains can be maintained only by a bending of grains about one another. PROBABLY the most obvious microstructural feature of heavily worked metals is the distorted shapes of grains. In the course of deformation, the shape change of each grain must be compatible with that of neighboring grains; otherwise holes would be formed at grain boundaries. In analyses of poly-crystalline deformation by Taylor and subsequent workers it was assumed that grain boundary compatability was maintained by each grain undergoing the same shape change as the polycrystalline aggregate in which it is imbedded. According to this assumption, when simple tension or compression is applied to a random polycrystal or to one with a fiber texture, each grain ought to deform with axially symmetric flow. Initially equiaxed grains should become cigar-shaped during wire drawing and pancake-shaped during compression. While microstructural observations of deformed metals are generally in accord with such a picture, certain striking exceptions may be noted. Peck and Thomas5'8 found that grains in heavily drawn tungsten, iron, and niobium (columbium) wires become shaped like ribbons curled about the wire axis, Fig. 1. At a suggestion from the author, they rationalized the development of these micro-structures by considering the orientation of the slip systems in the [011] texture formed by the wire drawing. It is shown in this paper that marked departure from axially symmetric flow of grains is also observed when polycrystalline aluminum is severely compressed. Again the explanation must lie in the orientation of the slip system in the [011] texture, which is formed in fcc metals by compression.' THEORY A simple quantitative argument will be presented to show that the development of these microstructures is a result of flow on the combination of slip systems for which the minimum amount of mechanical work is expended in producing a unit tensile (or compressive) strain. First it must be realized that the macroscopic strains of a crystal resulting from slip are given by: where d dy, and dc, are normal strain increments parallel to the x, y, and z reference axes; are crystallographic shear-strain increments on slip systems

Jan 1, 1964