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By W. H. Emmons

In 1922 Morey made a series of experiments in which he observed the cooling of a molten system containing H2O, 9.1 per cent; K2O, 17.3 per cent and SiO2, 73.6 per cent. This system was confined in a bomb; it was fluid at 500° C. and exerted no vapor pressure. In cooling to 420° C. a large part of it crystallized and at that temperature much of the water had separated from the crystals and remained as steam, which built up a pressure of 4998 lb. per sq. in., a force sufficient to lift nearly one mile of granite.' If granite, cooling at 600°, expels vapor in the process of crystallization it is reasonable to suppose that a considerably greater vapor pressure would result, and it is thought that the vapor expelled from crystallizing granitic batholiths probably has a pressure sufficient to lift two or three miles of granite. This vapor, collecting near the tops of cupolas of batholiths, is believed to exert sufficient pressure to fracture the hoods and roofs of batholiths above the cupolas. If that is true, one would expect to find that the fracture systems above cupolas are arranged in patterns that depend in part on the shapes of the cupolas. The mechanics of the situation seem to require that conical cupolas should have radial fracture patterns, that bluntly rounded cupolas should have fracture systems that are either irregular or rudely conjugated in plan, and that elongated stocks or cupolas should have fracture systems in which the fractu'res lie nearly parallel to the direction of the elongation of the cupolas. Study of essentially all the cupolas of the earth that have associated important vein-filled fractures shows that this is generally true. This

Jan 1, 1935

By C. E. Shoenfelt

Jan 1, 1942

By C. E. Shoenfelt

Jan 1, 1942

By John M. Tinsley, Calvin D. Saunders, H. K. van Poollen

In the past few years much con-sideration has been given to the evaluation of the effect of hydraulic fracturing on the productivity of wells. Generally, these studies included the evaluation of fracturing materials, fracture extension and formation damage due to the use of various fracturing fluids. Only little consideration has been given to the characteristics, and in particular the flow capacity, of the fracture itself and its effect on well productivity. This paper presents the results of laboratory investigations pointed toward fie evaluation of the efficiency of various fracrures with special emphasis on the flow capacity of these fractures. Data presented in this paper are the results of both an electrical model study and physical testing. Under consideration are (I) effect of overflush, (2) premature production of well after treatment, (3) "tailing-in" with coarse sand near the end of the treatment, (4) effect of propping agent size and concentration, (5) reduction in effective frac-ture permeability caused by formation caused by formation fines, silt and clays, and (6) effect of various fluids on formation strength and competency. The results of this investigation indicate that the flow capacity of a fracture is affected by any or all of the various parameters mentioned above. The authors believe that a better understanding arid utilization of these factors should result in more efficient formation fracturing. INTRODUCTION Hydraulic fracturing has become almost a standard practice of many companies for stimulating production from old and new wells. Although most companies utilize this service, techniques of application vary widely between companies and areas. Probably too often when a well in an area responds favorably to a particular technique all future wells in the same area are treated in a similar manner. Possibly a modification of the technique would result in a further production increase. Variables, of which many are extremely difficult to evaluate from field results, hamper the selection of procedure changes. Attempts are being made by a number of organizations to analyze statistically treating techniques from production data. This is a very worthy and necessary approach but very possibly laboratory investigations may aid in evaluating some of the variables which tend to affect the results of a fracturing treatment. Some of the factors cannot be studied from practical field experience and only laboratory tests can show the possibilities which might exist. One of the factors which appears to be of major concern today is the flow capacity of the created fracture and how it can be changed. Papers on this general subject have been primarily concerned with the size of propping agent and the extent of fracture. Papers have also been written on the possible permeability damage to formations by fracturing fluids. In addition, it might be possible that another type of flow restriction is prevalent. This would be a restriction of flow through a sand-packed frac- ture caused by foreign materials integrating within the propping agent. This paper presents preliminary data obtained in an attempt to evaluate the effect of some factors affecting flow through sand-packed fractures. No attempt is being made to offer a fracturing technique adaptable to all areas and conditions, but to furnish data tending to show the possible effects which might be caused by variations in procedures and materials. PROPPING AGENT PERMEABLLITIES A hydraulically induced fracture containing sand as a propping agent may theoretically be classified as a packed-sand system. The flow of fluids through such packed systems has been the subject of much research. Although there have been numerous methods proposed for the evaluation of such systems, most writers agree on the general properties affecting their flow capacity or permeability. These properties include porosity, particle size, sphericity and the roughness of the particle. In some methods of evaluation . the particle size and sphericity terms are combined to produce an equation which is a function of the surface area of the particles. In this study the permeability of various fracturing sands was both measured and calculated. The apparatus for the permeability measurements consisted of a 52-in. Lucite tube with a 2.5-in. ID. A screen and drain plug were fitted in the bottom of this tube to retain and hold the sand in place while allowing fluid flow. Two pressure taps consisting of thin, highly perforated

By JOHN R. SUMAN

IT SEEMS particularly appropriate that the Institute's Regional Meeting should be held in Minnesota this year. Whether we like it or not, we cannot help looking at things now in the light of the World War and the all-out effort we, as a nation, are making to defend our resources, our institutions, and our way of life. The ability to do this lies in large measure in the ability to forge weapons of defense-the machines of war. The basic ingredients of any defense system, or war machine, are the raw materials of industry-iron ore, providing steel for guns, shells, tanks, and warships; coal for stoking the nation's furnaces; oil to furnish power for war planes, ships, trucks, and mechanized weapons; and all the other materials that play a vital role in the operation of modern armies and navies. The tremendous requirements of full-scale defense programs are indicated by the large number of commodities that are now under priorities because the supply is not sufficient to meet both defense needs and all normal civilian consumption. But out of all these items two are of paramount importance-steel and petroleum. In this age no nation can hope to main¬tain a position as a first-class power in the world without a highly developed industry, particularly the heavy industries based on steel, and without access to the necessary resources for those industries. In 1918, 70 per cent of the iron and steel production of the United States was required for defense purposes. In 1940, 15 per cent of our iron and steel production was consumed for defense purposes, and with the acceleration of the defense program, it appears that the proportion of steel output required for defense purposes will reach 40

Jan 1, 1941

By W. C. Weslow

AN extended program devoted to the development of a matrix for holding diamonds of a size and. kind not heretofore generally used is being carried on by the Carboloy Company, and this paper describes the part of the development that affects mining and its allied industries. Labora-tory and field work so far has indicated the following: 1. Tungsten carbide and cobalt form the most desirable known matrix material for the holding of diamonds for drilling work. 2. Industrial bort diamonds in sizes and of a class not generally heretofore acceptable and therefore less expensive can be successfully held in this cemented carbide matrix. 3. In exploratory drilling, the combination of bort diamonds, impreg-nated throughout a matrix of tungsten carbide and cobalt, when fabri-cated onto drilling crowns, is an indicated economic substitute for drilling crowns in which the diamonds are set by hand, mechanically or by casting. 4. This impregnated type of drilling crown or bit has definite possi-bilites of revolutionizing the drilling of blast holes, particularly in the harder formations. This will be brought about by the development of high-speed light-weight rotary equipment using an impregnated diamond bit to replace the percussion drill now in general use. (The development of this rotary equipment is well past the laboratory stage at this time.) 5. That the use of a rotary bit is a preventive measure in the fight against silicosis. The development of this product was started by G. F. Taylor at the Research Laboratories of the General Electric Co. It was early recog-nized that it had possibilities in the drilling field and the present product is the result of considerable experimental work with other powdered metals as well as with tungsten carbide and cobalt.

Jan 1, 1940

By Emerson F. Heald

A systematic study was made of new and old data on chemical activities in Fe-Pt alloys at elevated ternperatuves. Experimental results may be expressed in terms of the excess free energy using Least-squares analysis of the data gave the following values for the constants: for the temperature range 1130° to 1350°C, and tentatively to 155O°C, B = -3.326564 and C = 0.221051; for the temperature range 650" to 850°C, B = -2.555690, C = 1.762735, and D =0.097196. In the study of iron-containing silicate systems, it is sometimes desirable to have a direct experimental measure of the activity of iron in the system. The well-known solubility of iron in platinum, often a headache in experimental work on iron compounds under reducing conditions, can be used to advantage in this respect. If the activity of iron in an Fe-Pt alloy in equilibrium with the silicate is known as a function of the composition of the alloy, chemical analysis of the alloy will give a knowledge of the activity of iron in all of the phases in the system. The present study was undertaken in order to elucidate the characteristics of Fe-Pt alloys as iron activity indicators. This work is intended to tie together some previous work, which may be summarized as follows. Larson and Chipman1 determined the activity of iron in Fe-Pt alloys at 1550°C by equilibrating platinum metal with calcium oxide-iron oxide-silica melts of known iron activity. Compositions of the resulting alloys were determined by chemical analysis. A similar study was carried out by Taylor and ~uan,' who worked at 1300°C. They brought the Fe-Pt alloys into equilibrium with iron oxide under conditions of known partial pressure of oxygen, and thus, from the work of Darken and ~urr~,~ conditions of known iron activity. Compositions were determined indirectly, by following the change in weight of the sample. Sundaresen et el* used the electromotive force of cells in which the alloy formed one electrode in order to measure the activity of iron in the alloy at 650" and 850°C. These temperatures were chosen to be above and below the first-order phase transition which takes place upon the ordering of Fe3Pt and the second-order transition which occurs upon the ordering of FePt3. EXPERIMENTAL 1) High Temperatures. The starting materials used were thin platinum foil, about 0.002 mm thick, and Fisher Certified reagent ferric oxide, Fez03, which had been heated for 24 hr at 1000°C. An intimate mixture of 80-mesh Fez03 and platinum platelets was placed in a thin platinum foil envelope. The latter was suspended from thin platinum wires in the hot zone of a vertical-tube, platinum-wound furnace of the type described by Muan and ~sborn.~ A capillary gas mixer similar to that used by Darken and Gurry3 was used to prepare a precisely known mixture of carbon dioxide and hydrogen, which was allowed to flow upward through the furnace tube. The partial pressure of oxygen in contact with the sample was thereby fixed at a value which was calculated from the charts prepared by porter? Temperatures were measured with a Pt-10 pct Rh-in-platinum thermocouple, which was calibrated using the melting points of gold (1062 .@C) and diopside, CaMgSizOB (1391.5"C). Temperature control was maintained to within i3"C with a Geophysical Laboratory proportional controller, using the furnace resistance as the sensing element. Samples were quenched by passing a small current through the platinum suspension wires, allowing the sample to drop into a bath of dibutyl phthalate at the bottom of the furnace tube. Prior to chemical analysis the samples were washed with acetone and dried. 2) Chemical Analysis. It proved possible, in almost all cases, to separate the Pt-Fe platelets physically from particles of iron oxide. The platelets were dissolved in a small volume of aqua regia, evaporated to dryness, and redissolved to 0.1 M HC1. In order to determine iron in the platinum alloy potentiometrically, it is necessary first to remove the platinum. A 10-cm column of Amberlite IR-120 cation exchange resin in the hydrogen form provided separation quickly and quantitatively: The mixture of iron and platinum in 0.1 M HC1 was added to the top of the column, and washed with about 100 ml of 0.1 M HC1. Under these conditions, the iron, principally in the form of cations such as FeC1" and FeCl;, is held quantitatively in the uppermost centimeter of the column. The platinum, in the form of anions such as PtC&- , is washed through without being adsorbed. After a qualitative test with stannous chloride indicated all of the platinum was removed, the iron was

Jan 1, 1968

By J. J. Becker

Changes in magnetic properties with particle size are used to study the precipitation process in a Cu-Co alloy. In particular, the effect of a field during aging in producing anisotropy is shown to occur entirely during the growth of the particles, after precipitation is complete. HEAT-treatment in a magnetic field is done commercially to improve the magnetic properties of a number of materials. These can be divided into solid-solution alloys and precipitation alloys. The Permalloys are representative of the first type, and magnetic annealing greatly increases their maximum permeability. On the other hand, in precipitation alloys such Alnico 5 the important result is an increase in maximum energy product. The effect of the field in all cases is to bring about an additional magnetic anisotropy, uniaxial in nature, which makes the hysteresis loop more upright when measured in the direction in which the field was applied. The structural origin of the anisotropy brought about by magnetic annealing is not well understood. In the solid solution alloys, one possible explanation is based on ordering.' Another possibility is the orientation of like-atom pairs.' The precipitation systems known to respond to magnetic heat treatment are Alnico 2, in which the effect was first discovered," Alnico 5, cobalt ferrite (oxide),' and Cu-Co alloys.3 n these materials, the field affects the precipitation process itself in some way. Although there has been much work on Alnico 5. its nature is still incompletely understood. According to Geisler,' the precipitation reaction is of the

Jan 1, 1959

The Institute maintains a dual relationship with students: (1) an individual relationship with a Student Associate; and (2) a relationship with local organizations of students, known as Affiliated Student Societies or Student Chapters. 1. The conditions of Student Associateship are set forth in Section 9, Article I, of the Bylaws of the Institute (see page 64 and following pages). During 1934, sundry amendments were made for the purpose of improving the student relationship. Postgraduate students are now eligible; and associateship can be maintained, with the payment of the regular dues of $2 per year, for 18 months following graduation in June. With his regular dues, each Student Associate is entitled to receive during the year his choice of MINING AND METALLURGY, METALS TECHNOLOGY, MINING TECHNOLOGY, PETROLEUM TECHNOLOGY, or two "classes" of Technical

Jan 1, 1943

By R. E. Whippo, B. L. Murowchick

The commercially exploited sedimentary apatites exhibit a number of variable lattice substitutions which affect their chemical composition. Carbonate is a major diluent of phosphorus values in sedimentary apatites. Substantial amounts of water as hydroxyl, hydronium, and tetrahedral hydroxyl ions substitute for fluorine and oxygen, calcium, and phosphate, respectively. Calcium is also replaced by several other divalent and monovalent cations. The structural formula demonstrates the substitutions in the lattice of the sedimentary apatites studied in view of the crystal-chemical relationships which have been postulated for the isomorphous apatite series. The lattice constant a. varies from 9.29 to 9.40 A for the apatites studied. Quantitative relationships between this constant and lattice substitution are complicated by the interaction of multiple substitutions whose influence is non-additive. The mineral apatite, the principal raw material source of phosphorus for agricultural and industrial applications, offers a wide area for investigation. Considerable research effort has been expended in the study of apatite crystal-chemistry by medical, biological, and earth scientists. Few of these studies deal directly with the sedimentary apatites from the major occurrences which are widely exploited for commercial uses. It is the purpose here to present chemical analyses of several sedimentary apatites and discuss their chemical composition in relation to the structural and crystalchemical principles which have been postulated for the apatite isomorphous series. THE STRUCTURE OF FLUORAPATITE The atomic structure of fluorapatite was described, independently, by Ngray-Szabd and Mehmel in 1930 and has been accepted as presented, with only minor changes,4 since that time. The hexaogonal unit cell with dimensions of a = 9.37 0.01 A and c = 6.88 0.01 A contains two molecules of the composition "There are six (PO4) groups in the cell, four calcium ions on the trigonal axes, surrounded prismati-cally by six oxygen ions and six calcium ions surrounded by an irregular polyhedron of a fluorine and five oxygens. Fluorines are at the comers of the reflexion planes, touching three calcium ions each".l7

Jan 1, 1968

By C. H. Stewart, R. A. Fagin

A two-dimensional, three-phasereservoir simulator was programmed for a large memory digital computer. It was designed to provide a practical solution to describing the complex physical relation between the natural forces and the physical properties of a heterogeneous reservoir when subjected to a specific set of conditions. A reservoir study is briefly described to illustrate application of the model. A full volumetric account of three phases (oil, gas and water) is performed simultaneously throughout an integration net representing the reservoir. Absence of one or two of the phases is treated as a special case of the more general situation. Expansion (or contraction) of all phases, including rock expansion, is performed so that the pressure calculation is the general unsteady-state case. To account for the large variations of subsurface elevation encountered in some reseruoirs, and to allow for segregation of the various phases, a gravity head term is included in the basic drive potential. Appropriate fluid and rock properties are used in polynominal surface form (functions of pressure and/or depth) or they can be entered as space variables at each position of the integration net. An unsteady-state water influx calculation, based on the method of van Everdingen and Hurst, l was connected to the boundary of the matrix to simulate aquifers of various sizes. In addition to reservoir calculations, three-phase fluid flow from the producing depth to the wellhead, including provisions for gas lift, was incorporated in the simulator. A workover routine was also built which can automatically switch to a different set of production relations when a gas-oil ratio or water fraction reaches a limit; or it can shut-in the well if prescribed. INTRODUCTION This paper describes a reservoir engineering mathematical simulator used to represent the complex interaction of natural forces and physical properties of a reservoir during natural depletion or with various injection schemes. The simulator, which was programmed for a large memory digital computer, is a two-dimensional calculation which handles three mobile fluid phases simultaneously (oil, gas and water). Basic requisites for the method are individual well production and pressure data, hydrocarbon fluid properties, geological data (producing depth and net sand), capillary pressure data, relative permeability data and permeability and porosity information. Matching the past performance of a combination drive reservoir often has yielded information concerning continuity and the validity of basic data. Detailed predictions of future performance can be made for continuation of current depletion methods (natural depletion) as well as for various types of recovery by gas or water injection. Combination injection cases and pattern studies can also be performed. Workover programs, gas lift and different types of artificial lift programs have been investigated using a technique similar to that described by Kern and Nicholson2 except that conditions of pressure and saturation at the block within which the well is located are used rather than average reservoir conditions. Drilling additional wells to optimize profit was explored, both as to number and location, by placing wells at different spots within the reservoir matrix. Special depletion processes can be examined, such as upstructure drainage and lateral (or strike) waterfloods in thin oil columns. In one case the mathematics of the simulator were modified to calculate the displacement in the vertical plane rather than in the horizontal plane. In this manner specific reservoir problems can be studied, such as coning of gas and/or water around production points, fingering along permeable stringers or, more generally, frontal advances in a heterogeneous section.

Jan 1, 1967

By Fred C. Bond

AN improved method of measuring the surface area of a comminution product down to any desired particle size has been developed. The method is largely graphical, and requires relatively little calculation. It can be used with materials containing large amounts of clay, or excess fines of any kind. The surface area S is expressed in terms of square meters per100 c.c. of solids. This expression is based upon volume rather than weight, and is considered to be more suitable for crushing and grinding problems, where the machines ordinarily are operated under constant volume conditions. It has the advantage that surface areas of different materials can be compared directly, even though their specific gravities may be unknown. The "specific surface" of a material, or the number of square centimeters of surface area per gram, is equal to 100S divided by the specific gravity. Particle diameters are expressed in microns, K being the diameter of the largest particle present and L the grind limit, or lower size limit of the particles formed directly by grinding. The value of K does not always coincide exactly with the diameters of the largest particles retained on the coarsest testing sieve, since the largest particles formed in crushing and grinding are often slabby, or have other irregular shapes. L has been chosen as 0.700 microns, or number 27.5 in the size number series,1 for reasons to be explained later. S is the total surface area of all particles larger than L microns in diameter. When a homogeneous comminution product is separated into fractions whose diameters bear a constant geometrical relationship [p] to each other, and the log per cent weight retained upon each size and passing the next larger size is plotted against the log diameter, a straight line results, which is called the distribution line, and which has a slope in called the distribution modulus. The distribution line can be extended to any desired limiting size, and the total surface area of all particles larger than that size can be calculated. The equation of the distribution line is w = Cxm [I] where w is the per cent weight retained on each successive sieve; x is the particle diameter; and C is the per cent weight retained on an opening of unit diameter.2 Theoretically, the distribution line can be extended to include infinitely small particles. When it is so extended, and the assumption is made that no fine particles are present other than those accounted for by the equation; the log per cent cumulative weight passing any series of sizes, plotted against the log diameter passed, will result in a straight line lying parallel to and above the plotted distribution line.

Jan 1, 1941

By H. M. Howe, E. C. Groesbeck

Fig. 1 shows a volute aging break which developed spontaneously in a hardened and tempered steel helmet between 19 and 38 days after it had been tested ballistically. A similar break, shown in Fig. 2, developed spontaneously in a similar helmet about 40 days after the ballistic testing. In this case the rupture occurred abruptly and with a loud report. The path of rupture in this second case, though much the less regular, is the more interesting of the two, in that it is an approximation to two parallel volutes centered at the point of impact of the projectile, just below D. Several weeks later, after the photograph for Fig. 1 was taken, a similar doubling of the volute crack occurred in this helmet, starting from the end of the eyelash crack near A and spreading thence to the left contra-clockwise for about 1/2 in. The negatives from which these pictures are made have not been touched up in any way, save writing the letters on them. In both cases the trajectory of the bullet was normal to the initial surface at the point of impact, and in both the helmet passed the ballistic test without detectable cracking, under a velocity of impact not far below that which usually causes perforation. The initial surface itself was very nearly spherical throughout the region covered by the break.

Jan 1, 1920

By REED H. HYDE

IN these days of low metal prices and difficult marketing conditions, any treatment that will improve the grade of a product is of interest, particularly when the operation involves little or no addition to the total cost and may even result in a marketable by-product. Such a' combination of circumstances exists, in some cases, in the zinc industry, where it has been found that certain impurities can be removed from .the ore during the Dwight-Lloyd sintering operation, previous to reduction to metal. Consequently it is not surprising that zinc smelters having these sintering machines are paying particular attention to this phase of the operation. Loss of zinc as fume is very low under the conditions obtaining in sintering zinc ores, but impurities such as cadmium and lead are more readily fumed off and it is on this fact that the purification is based. As a result of preferential volatilization of these impurities a sintered product' is made from which purer zinc metal or oxide can be produced, while the fume may be collected and treated to recover the impurity metals. To be effective the operation must be carefully conducted, but no special equipment other than that of a well designed Dwight. Lloyd plant is needed.

Jan 1, 1931

VARYING in thickness and in number from place to place, coal seams in the Canadian Rockies also range in pitch from nearly horizontal to vertical, sometimes with overturns. Over the entire coal-bearing area there are considerable differences of rank in coals of the same geological age, and there are marked differences in ash content and washability characteristics. Correlation of seams at mining operations within a few miles of each other has often proved impossible. These factors influence mining methods, and, of course, production results. The oldest coal formations of western Canada are of Lower Cretaceous age, as the carboniferous sediments are marine and contain no coal. Coal is also present in formations of Upper Cretaceous and Tertiary ages. The rank of coal varies from semianthracite in some operations in the Kootenay and Luscar formations of the Lower Cretaceous in the Rockies to lignite in the Tertiary fields of the Saskatchewan prairies. Fig. 1 shows the general extent of the formations.

Jan 8, 1954

By Evan Just

DIRECT subsidies for mine production in this country began as an outgrowth of wartime 'price regulation. The price-fixing authorities realized that the volume of production to be required from domestic copper, lead, and zinc mines would invoke costs of production considerably higher than the established ceiling prices. Accordingly, beginning Feb. 1, 1942 the Premium Price Plan was set up, which undertook to pay premiums to mines for production in excess of quota, of 5¢ per lb of copper and 2Y4¢ per lb of zinc or lead. Quotas, except for small mines, were initially established at the average rate of production in 1941, but were later reduced arbitrarily on an individual basis. Subsequently, additional "B" premiums were set for lead and zinc of 2Y40 per lb and a further "C" zinc premium of 2%¢. Additional copper premiums were negotiated on an individual basis, mainly with small mines. Quotas under each of these successive categories were the production obtained at the next lower premium level. In other words, under ceiling prices of 12¢ for copper, 6,14¢ for lead, and 83¢ for zinc, it was possible for high-cost operations to receive prices plus premiums of 17¢ or more for copper, 12¢ for lead, and 16% 0 for zinc on a portion of their production. On the other hand, some of the larger operators received only slight premiums and in at least one instance none at all. The average price plus premium for copper was 12.25¢ in 1942 and rose to 13.65¢ in 1945. That for lead was 6.99¢ in 1942 and 8.73¢ in 1945, and for zinc it was 9.06¢ in 1942 and 11.200 in 1945.

Jan 1, 1948

By W. G. Matteson

In 1915, the State of California passed a law of great scope and importance. This law has been in successful operation for a year and may be briefly described as an act " establishing and creating a department of the State Mining Bureau for the protection of the natural resources of petroleum and gas from waste and destrucbion through improper operations in production; providing for the inspection of petroleum and gas wells; requiring all persons operating petroleum and gas wells to make certain reports" and providing the necessary officers and assessments to carry out the provisions of the act. The statute provides for a separate department of the State Mining Bureau, under the general supervision of the State mineralogist, with a staff composed of a "state oil and gas supervisor" and four deputies. It rules that all petroleum and natural gas wells shall be drilled, operated or abandoned under the supervision of the State supervisor, who shall order such tests or remedial work as seems to him necessary to protect the interests of property owners and the general public. It also provides for a board of arbitration to consider orders given by the supervisor which are not acceptable to the well owner. Section 18 of the act, which is the provision that is directly related to this paper, requires ('the owner of any well referred to in this act to keep a careful and accurate log of the drilling of such well," and further requires that this log shall show the character and depth of the formations passed through or encountered in the drilling, particularly the location and depth of the water-bearing strata; the character of the water encountered (so far as ascertained); whether the water was shut off, and, if solat what point; that it shall show completely the amounts, kinds and size of casing used; the depth at which oil-bearing strata are encountered; the depth and character of the strata, and whether all water was successfully and permanently shut off so as to prevent percolation or penetration into the oil-bearing strata. This log is to be kept in the local office of the owner or operator, subject to the inspection of the supervisor or any of his deputies at any

Jan 1, 1917

By H. W. Norman

DURING the first few years of the new atomic age the Colorado Plateau was the focal point of uranium exploration. There was little incentive to expend time and effort in an area so far removed from the known deposits as the Pacific Northwest, and there were too few local prospectors to cover the vast territory involved. In 1949 the AEC established an exploration office in Spokane to evaluate the uranium potential of the northwestern states. Interesting occurrences were found in the Coeur d'Alene district in Idaho and in the Boulder Batholith of central Montana, but the AEC discontinued the Spokane office in 1952, and for the next two years prospecting in the area was negligible. In April 1954 John and James LeBret, prospecting on the Spokane Indian Reservation with an ultra violet lamp, located an occurrence of the fluorescent uranium mineral autunite. This discovery was not announced until the following September, after a lease had been granted by the Spokane tribe. Exploratory drilling carried on by the AEC throughout the winter verified the existence of a commercial orebody. This property, the Midnite mine, has since developed the largest known ore reserve in the district.

Jan 6, 1957

By G. Sachs, G. Espey

It is well known that high residual stresses are created in tubing by the sinking process, in which no internal tool or mandrel is used.l-4 In this process, the wall thickness is usually slightly increased.4,5 In tube drawing with a plug, the residual stresses are gradually reduced with increasing reduction of wall, and, by the conventional approximation methods of stress measurement, no stress is detected in tubing in which the wall reduction is over 50 per cent of the total reduction in cross-sectional area.l,6 It has also been observed that higher stresses are set up by the use of wide-angle dies than by acute dies.? 'he actual stress distribution in drawn tubing has been investigated by a few workers,7"9 but has not been related to the conditions of the drawing process. Some attempts have been made to correlate accelerated cracking tests for stresses in brass products with the magnitude of the circumferential stresses and the condition of the metal. l-10 Materials and Preparation The material used in this experiment was commercial cartridge-brass (70 per cent Cu, 30 per cent Zn) tubing in the straightened and annealed condition.† This tubing was of various outside diameters and had a wall thickness of 0.032 in. It was sunk to 1/2-in. outside diameter by means of an experimental 10,000-lb. hydraulic draw-bench, with a maximum drawing speed of 8 ft. per minute. All dies were of 1/2-in. diameter. Various die materials and contours were used in order to study the effect of die design on residual stresses in the tubing; the specifications for the dies are given in Fig. I. Castor oil was used throughout as lubricant. Chattering occurred in sinking some of the tubing, particularly when dies having the more acute angles were used, but the tubes showing chatter marks did not differ markedly from those with a smooth surface regarding the magnitude of residual stress. The source of the chattering has not yet been revealed. The wall of the tubing becomes thicker during s nking, as previously observed.4,5 The increases in wall thickness were 3, 7 and 9.5 per cent on the average for 6, 20 and 33 per cent reductions in diameter, no effect of the contour being noticeable. The reductions mentioned throughout this investigation do not consider this fact, but are reductions of the outside diameter. For the evaluation of the residual stress two fundamentally different methods were used. The approximation methodl,ll of splitting a certain length of tubing was employed to obtain a bird's-eye view of the effect of various drawing conditions on the circumferential stress measured by the diameter change occurring On splitting. For

Jan 1, 1942

By G. Sachs, G. Espey

It is well known that high residual stresses are created in tubing by the sinking process, in which no internal tool or mandrel is used.l-4 In this process, the wall thickness is usually slightly increased.4,5 In tube drawing with a plug, the residual stresses are gradually reduced with increasing reduction of wall, and, by the conventional approximation methods of stress measurement, no stress is detected in tubing in which the wall reduction is over 50 per cent of the total reduction in cross-sectional area.l,6 It has also been observed that higher stresses are set up by the use of wide-angle dies than by acute dies.? 'he actual stress distribution in drawn tubing has been investigated by a few workers,7"9 but has not been related to the conditions of the drawing process. Some attempts have been made to correlate accelerated cracking tests for stresses in brass products with the magnitude of the circumferential stresses and the condition of the metal. l-10 Materials and Preparation The material used in this experiment was commercial cartridge-brass (70 per cent Cu, 30 per cent Zn) tubing in the straightened and annealed condition.† This tubing was of various outside diameters and had a wall thickness of 0.032 in. It was sunk to 1/2-in. outside diameter by means of an experimental 10,000-lb. hydraulic draw-bench, with a maximum drawing speed of 8 ft. per minute. All dies were of 1/2-in. diameter. Various die materials and contours were used in order to study the effect of die design on residual stresses in the tubing; the specifications for the dies are given in Fig. I. Castor oil was used throughout as lubricant. Chattering occurred in sinking some of the tubing, particularly when dies having the more acute angles were used, but the tubes showing chatter marks did not differ markedly from those with a smooth surface regarding the magnitude of residual stress. The source of the chattering has not yet been revealed. The wall of the tubing becomes thicker during s nking, as previously observed.4,5 The increases in wall thickness were 3, 7 and 9.5 per cent on the average for 6, 20 and 33 per cent reductions in diameter, no effect of the contour being noticeable. The reductions mentioned throughout this investigation do not consider this fact, but are reductions of the outside diameter. For the evaluation of the residual stress two fundamentally different methods were used. The approximation methodl,ll of splitting a certain length of tubing was employed to obtain a bird's-eye view of the effect of various drawing conditions on the circumferential stress measured by the diameter change occurring On splitting. For

Jan 1, 1942