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By R. Laird Auchmuty

The A. I. M. E. Subcommittee on Bituminous Mining has been trying for several years to secure the information that was collected by the Marquette Cement Manufacturing &. on the subsidence of its property caused by mining coal beneath it. The Marquette company was willing to have these data used, but it was impossible to obtain them because the records had been filed away. About two years ago these records became available and the engineering data presented herewith were compiled from them by R. L. Auchmuty, assisted by L. E. Young, who was connected with the collection of the information. On account of the cost, it is impossible to reproduce all of the data here, although the original information is on file with the records of the Committee on Ground Movement and Subsidence. The accompanying charts show representative and average data and give only the engineering information with enough description to tell how it was obtained. It is hoped that all of those connected with the original case will participate in the discussion that this will bring forth. Howard N. Eavenson, Chairman, Subcommittee on Bituminous Coal Mining. PRobably the most complete records of subsidence due to coal mining in the United States are those compiled by the Marquette Cement Manufacturing Co. at LaSalle, 111. These records, covering a period of more than three years, were compiled and used as evidence during the suit of the Marquette Cement Manufacturing Co. vs. the Oglesby Coal Co. at Oglesby, LaSalle County, Ill., in which the cement company successfully endeavored to stop the coal company from mining under its property. Fig. 1 shows a typical section of the geological formation. The cement company was mining the LaSalle limestone which lies about 125 ft. under the surface. The limestone is 30 to 35 ft. thick and underlain by about 15 ft. of shale. The cement company was mining about 20 ft. of the limestone, and in some places 10 to 12 ft. of the underlying shale, by the room and pillar method. The mining of the limestone always preceded the mining of the shale. The coal company was mining by longwall advance methods the NO. 2 seam of coal 42 in. thick underlying the limestone bed by 435 to 470 ft. The coal mine, a very old one, had largely mined out its original property

Jan 1, 1931

By R. B. Gilmore

The North Texas district, as herein defined, includes the counties of Archer, Baylor, Clay, Cooke, Foard, Hardeman, Jack, Kiiox, Montague, Wichita, Wil-barger, and Young. Jack and Young Counties are included for the first time so that this district will correspond with District No. 9 of the Texas Railroad Commission. This area covers generally the crest and south flank of a system of buried mountains known as the Red River uplift. The oil and gas accumulations along this feature are in traps, which, although localized by structures incident to the regional uplift, usually are modified by stratigraphic changes in the sediments. The structural deformation caused by the Red River uplift is modified by the Rend arch, which is a broad anticline plunging northward from the Llano uplift in central Texas through Young and into Archer Counties. The fields in southern Archer, southeastern Baylor, southwestern Clay, and western Jack Counties arc on the extreme north end and along the flanks of the Bend arch and have generally the same type of oil and gas accumulation as the other fields in this district. Recent exploration has been along the flanks of the Fort Worth syncline, which is east of the Bend arch and south of the Red River uplift and extends into southeastern Clay and southwestern Montague Counties and along the eastern part of Jack County. The larger part of past oil and gas produc- tion has come from Pennsylvanian strata, with less important amounts lrom the Permian, and minor quantities from the Mississippian and Ordovician. Developments during 1943 About 1100 wells were drilled in the district during 1943 and more than 500 oil wells were completed, an increase from 1942. of approximately 12 per cent in the number of successful drilling operations of the total wells drilled. The addition of Jack and Young Counties to this district accounts for part of this increase, almost 150 wells being completed in the two counties. Production increased slightly over the previous year as a result of an increase in the number of producing wells and a greater demand for this high-gravity, sweet crude oil. The average depth of discovery wells was about 400 ft. deeper than in 1942. Although more discoveries produced from horizons below the base of the Strawn series than from those above the Straw, the deeper horizons, including the Bend series of the Pennsylvanian, the Mississippian limestone and Ellenburger of the Ordo-vician, largely were dissappointing from the viewpoint of major additions to oil reserves. The largest single addition to the reserves was in the basal Strawn sand in the Walnut Bend field, Cooke County. During the year, 31 wells were completed, both in the field and as cxtensions. The most active arca Was Jack County, in which five fields or potential fields were discovered, although only 44 oil wells were completed.

Jan 1, 1944

By R. B. Gilmore

The North Texas district, as herein defined, includes the counties of Archer, Baylor, Clay, Cooke, Foard, Hardeman, Jack, Kiiox, Montague, Wichita, Wil-barger, and Young. Jack and Young Counties are included for the first time so that this district will correspond with District No. 9 of the Texas Railroad Commission. This area covers generally the crest and south flank of a system of buried mountains known as the Red River uplift. The oil and gas accumulations along this feature are in traps, which, although localized by structures incident to the regional uplift, usually are modified by stratigraphic changes in the sediments. The structural deformation caused by the Red River uplift is modified by the Rend arch, which is a broad anticline plunging northward from the Llano uplift in central Texas through Young and into Archer Counties. The fields in southern Archer, southeastern Baylor, southwestern Clay, and western Jack Counties arc on the extreme north end and along the flanks of the Bend arch and have generally the same type of oil and gas accumulation as the other fields in this district. Recent exploration has been along the flanks of the Fort Worth syncline, which is east of the Bend arch and south of the Red River uplift and extends into southeastern Clay and southwestern Montague Counties and along the eastern part of Jack County. The larger part of past oil and gas produc- tion has come from Pennsylvanian strata, with less important amounts lrom the Permian, and minor quantities from the Mississippian and Ordovician. Developments during 1943 About 1100 wells were drilled in the district during 1943 and more than 500 oil wells were completed, an increase from 1942. of approximately 12 per cent in the number of successful drilling operations of the total wells drilled. The addition of Jack and Young Counties to this district accounts for part of this increase, almost 150 wells being completed in the two counties. Production increased slightly over the previous year as a result of an increase in the number of producing wells and a greater demand for this high-gravity, sweet crude oil. The average depth of discovery wells was about 400 ft. deeper than in 1942. Although more discoveries produced from horizons below the base of the Strawn series than from those above the Straw, the deeper horizons, including the Bend series of the Pennsylvanian, the Mississippian limestone and Ellenburger of the Ordo-vician, largely were dissappointing from the viewpoint of major additions to oil reserves. The largest single addition to the reserves was in the basal Strawn sand in the Walnut Bend field, Cooke County. During the year, 31 wells were completed, both in the field and as cxtensions. The most active arca Was Jack County, in which five fields or potential fields were discovered, although only 44 oil wells were completed.

Jan 1, 1944

By C. S. Barrett

The torsional after-effect in polycrystalline cadmium is interrupted by an abnormal twisting when the film is removed by etching. This is accounted for by the pile-up of dislocations beneath anodic or other oxide films during the original twisting, and the relief of the residual stresses from these by elastic and plastic processes during etching. WHEN an iron or zinc wire coated with oxide is plastically twisted and then released, it untwists according to a law of equal increments in equal intervals of log time, but if the oxide is suddenly removed by etching this normal after-effect is interrupted by a transient, and thereafter the untwisting is slower.' Etching may even reverse the strain temporarily. Related effects caused by hydrated oxide films on cadmium in creep tests have been observed by Phillips and Thompson:' definite transient strains caused by the removal of the film from single crystals of cadmium were observed; however, negligible effects were obtained with polycrystalline wires. Pronounced effects of both transient and steady nature were observed by Phillips and Thompson when anodic films 10-4 cm thick were etched off, and weak effects, transient only, occurred with hydrated oxide films 3x10 cm thick such as were formed by standing in water for 10 min. It was estimated that 10.' cm films, formed in water in 1 or 2 min, could be detected in the apparatus of Phillips and Thompson. Since abnormal after-effects were observed by the torsion method equally well with polycrystalline and monocrystalline iron and zinc wires,' it was anticipated that the torsion method would also disclose them in polycrystalline cadmium, in spite of the fact that analogous effects had not been observed in tensile creep tests on polycrystalline zinc by Pickus and Parker3 r on polycrystalline cadmium in tensile studies by Andrade and Randall." Because of its high sensitivity, particularly its sensitivity to surface conditions, the torsion method was thought to merit further study as a method of investigating thin films of various types and the action of various reagents on these films. Materials and Methods Cadmium wires were cold-drawn to a diameter of 0.039 in. from a stock that was determined spectro-scopically to contain 0.05 pct Bi, 0.005 pct Cu, 0.008 pct Pb, and 0.007 pct Si. The wires were cut to about 17/8 in. lengths and were annealed 1 hr in air at 290°C, after which the grain size was such that there were 5 to 7 grains across a diameter. The wires were then mounted as indicated in the insert in Fig. 1, one end being fastened with laboratory wax into a small diameter brass tube and the other end being waxed to a thin glass fiber which supported, on its upper end, a small galvanometer mirror. The wires were waxed with care to avoid straining or annealing, for it was found that the after-effect rate was sensitive to prior cold work in a wire. The assembly was then clamped above a beaker into which the reagent could be poured. The lower end of the wire was held in the hand while the wire was twisted 180"; it was then released immediately. Since precision timing of these manipulations was not attempted, the different wires cannot be compared as to exact rates of untwisting. The length subjected to plastic strain was 15/8 in. The surface coatings studied were those produced by the annealing in air, by anodic treatment of

Jan 1, 1954

By W. W. Smeltzer

The linear formation rates of wustite films have been determined over the temperature range 590° to 1030°C using a vacuum microbalance technique. These rates are dependent directly on the partial pressure of carbon dioxide, Activation energies for film and scale formation in carbon dioxide and oxygen atmospheres are equivalent to either the dissociation energies of carbon dioxide and oxygen, or the activation energy for the diffusion of cation vacancies in wustite. Of the metals, iron is the most widely used basic constituent of durable alloys despite its intrinsic property of converting at a relatively rapid rate to the oxides from which it is derived. This property has accounted partially for many investigations on the oxidation of iron at low and high temperatures. Interpretation of the results have been complicated by formation of multilayers containing the various oxide phases. To aid in elucidation of the oxidation kinetics, measurements have been carried out in this investigation on the growth of the wustite surface layer. There are several studies directly related to the objective of this investigation. The growth of multilayer scales has been demonstrated to be diffusion controlled in oxygen at atmospheric pressure over the temperature range 450" to 1200°C by Davies, Simnad, and Birchenall.' To gain an insight into the diffusion mechanism, Himmel, Mehl, and ~irchenall' determined the self-diffusion coefficients of iron in wustite, magnetite, and hematite. These results were used to evaluate the oxidation rates of iron and its oxides, taking as a basis the theoretical parabolic rate equation developed by Wagner., The evaluations were compared to experimental data and were shown to provide essential confirmation of this theory. Fischbeck, Neundeubel, and salzer4 have demonstrated that the oxidation of iron in carbon dioxide and other atmospheres at high temperature obeys a linear relationship. Because the Arrhenius temperature coefficients of the reaction rate constants changed at the A, point they concluded that the passage of iron into the oxide controlled the reaction. This viewpoint has been accepted by Benard and ~albot' to explain the occurrence of linear rates in oxygen before the onset of diffusion-controlled parabolic oxidation. This basic premise of a rate-controlling reaction at the iron/oxide interface has been questioned recently by Hauffe and Pfeiffer.' Since the formation of wustite may follow a linear or parabolic relationship depending on the pressure of the gaseous re-actant, they propose that linear oxidation is determined by a chemisorption reaction while parabolic oxidation is controlled by diffusion. As confirmation of this viewpoint, Hauffe and pfeiffer6 and Pfeiffer and ~aubmeyer' have established that the linear scaling constants of wustite formation at 1000°C in carbon-dioxide or low-pressure oxygen atmospheres

Jan 1, 1961

By David B. Reger

Wildcat drilling for new supplies of gas and the expansion of previously discovered oil and gas pools were the principal petroleum activities in West Virginia .during 1942. Much of the new gas exploration is still uncompleted and still indecisive but various wildcats made substantial extensions to existing pools. Out of 53 wildcats drilled 27 resulted in commercial gas and 6 in commercial oil. Four of the oil discoveries also had commercial gas. No strictly new pools of oil or gas can safely be described as discovered but several scattered oil and gas wells previously drilled have been confirmed as the openers of definite pools; also, various completions closed wide gaps between apparent gas pools already discovered. The proved oil territory of the state was increased about 4850 acres and the proved gas territory about 51,000 acres. The new proved oil reserves should about balance withdrawals and the new gas may represent a substantial increase. Aside from the drilling in four rather lively pools, oil activity was slight because of unfavorable operating conditions and prices. Gas drilling also declined for reasons beyond the control of the operators. The account of operations, as gathered from trade journals and other reporting services, shows that 797 new wells were drilled, providing 119 new oil wells with 2762 bbl. of daily new production; 536 new gas wells with 1,228,501,000 CU. ft. of daily open flow: and 142 dry holes. Also... 76 old wells were drilled to deeper sands, with 71 bbl. and 26,034,000 cu, ft. of added production. On the new wells the oil average was 23.21 bbl. per well per day; and the gas average was 2,270,406 CU. ft. per well per day. On new wells the ratio of dry holes to completions was 17.82 per cent. On deeper drilling the ratio of failures was 21.05 per cent. Production of oil for the year was estimated by the Oil ad Gas Journal as 3,492,000 bbl., as compared with 3,378,000 bbl. in 1941. Production of natural gas for the year is estimated by the author as 220,000,000,000 cu. ft., as compared with the U. S. Bureau of Mines final figures of 207,000,000,000 cu. ft.* in 1941. General State op Industry Leasing of wildcat acreage increased considerably. The total land of all classes under lease may now exceed 5,000,000 acres. Taking into consideration completions, abandonments and corrected figures or estimates, Table I shows cumulative and late annual statistics. New Pools and Extensions Table 2 shows the principal areas of drilling activity during 1942. Various consolidations of territory, hitherto treated as separate pools, have been made. in addition to these active pools, extensive drilling was done in numerous other areas where pool boundaries can hardly be defined. Summary or Exploration Table 3 gives a summary of important wildcat or exploratory wells drilled during

Jan 1, 1943

By David B. Reger

Wildcat drilling for new supplies of gas and the expansion of previously discovered oil and gas pools were the principal petroleum activities in West Virginia .during 1942. Much of the new gas exploration is still uncompleted and still indecisive but various wildcats made substantial extensions to existing pools. Out of 53 wildcats drilled 27 resulted in commercial gas and 6 in commercial oil. Four of the oil discoveries also had commercial gas. No strictly new pools of oil or gas can safely be described as discovered but several scattered oil and gas wells previously drilled have been confirmed as the openers of definite pools; also, various completions closed wide gaps between apparent gas pools already discovered. The proved oil territory of the state was increased about 4850 acres and the proved gas territory about 51,000 acres. The new proved oil reserves should about balance withdrawals and the new gas may represent a substantial increase. Aside from the drilling in four rather lively pools, oil activity was slight because of unfavorable operating conditions and prices. Gas drilling also declined for reasons beyond the control of the operators. The account of operations, as gathered from trade journals and other reporting services, shows that 797 new wells were drilled, providing 119 new oil wells with 2762 bbl. of daily new production; 536 new gas wells with 1,228,501,000 CU. ft. of daily open flow: and 142 dry holes. Also... 76 old wells were drilled to deeper sands, with 71 bbl. and 26,034,000 cu, ft. of added production. On the new wells the oil average was 23.21 bbl. per well per day; and the gas average was 2,270,406 CU. ft. per well per day. On new wells the ratio of dry holes to completions was 17.82 per cent. On deeper drilling the ratio of failures was 21.05 per cent. Production of oil for the year was estimated by the Oil ad Gas Journal as 3,492,000 bbl., as compared with 3,378,000 bbl. in 1941. Production of natural gas for the year is estimated by the author as 220,000,000,000 cu. ft., as compared with the U. S. Bureau of Mines final figures of 207,000,000,000 cu. ft.* in 1941. General State op Industry Leasing of wildcat acreage increased considerably. The total land of all classes under lease may now exceed 5,000,000 acres. Taking into consideration completions, abandonments and corrected figures or estimates, Table I shows cumulative and late annual statistics. New Pools and Extensions Table 2 shows the principal areas of drilling activity during 1942. Various consolidations of territory, hitherto treated as separate pools, have been made. in addition to these active pools, extensive drilling was done in numerous other areas where pool boundaries can hardly be defined. Summary or Exploration Table 3 gives a summary of important wildcat or exploratory wells drilled during

Jan 1, 1943

By Dick Whittington, W. R. Taylor

GENERAL In mid-1974, a representative of ARCO Petroleum Company walked into our Austin offices and asked for a permit for ARCO's first Clay West Mine site. This was the first in situ uranium mining permit issued in the United States. That initial permit, issued in January 1975, was for three acres. The four years since have been characterized by growth and change. Today there are 16 permits approved for approximately 1,540 production acres issued to five companies at eight sites in four counties. There are approximately seven additional permit applications being processed or on the verge of being submitted for an estimated 2,000 additional acres of production. As a rough gauge of the financial scope of this activity, at the typical 40 production wells per acre and an estimated $2,000/well, operators hale installed or committed $122 million for production wells. This does not account for the exploration and development wells installed to delineate the ore or the cost of processing facilities for extracting the uranium. HISTORY OF URANIUM MINING IN TEXAS Information I have concerning early in situ uranium mining activities is "sketchy" but the apparent first on-site test of in situ uranium mining was conducted between 1967 and 1971 at the Dueterstat site, north of Yorktown in Gonzales County, by City Service. Others ran tests at the Bruni site in Webb County and the Burns and Clay West sites in Live Oak County in the mid-70's. During this period, Texas Water Quality Board personnel in the central and district offices maintained a general surveillance of these various test activities. Regulation of in situ uranium mining was formalized with the issuance of a permit in January 1975 with the advent of ARCO's initial production scale (3 acre) effort in the Clay West area at the Moser mine site. Since 1975, the accelerating rate of mining and exploration activity is noticeable. There were 16 exploratory rigs operating early in 1977. This year, the rig count is averaging 46--a 287% increase. HISTORY OF LEGISLATION Paralleling this mining activity was state and federal legislation which subjected in situ mining to environmental regulation. The following is a brief chronology of the legislation that is directly or indirectly related to uranium mining. As most of you know, disposal wells are an integral part of most in situ uranium mines operating in Texas. They are used both during production and during aquifer restoration following production. The wells are regulated by the Texas Injection Well Act, enacted in 1961 by the Texas Legislature. In 1967, the Water Quality Act established the Texas Water Quality Board, and provided for the regulation of water quality by the so-called permit system. In 1969, the Solid Waste Act was enacted by the Texas Legislature. The legislation provides for control of wastes from manufacturing, mining, and agriculture. This Act regulated uranium surface mining activities until 1975 when the Texas Surface and Mining Reclamation Act placed responsibility with the Railroad Commission for uranium open-pit mining and surface mining of coal and lignite. In 1972, the Federal Water Pollution Control Act (Public Law 92-500) was passed. This legislation forms the legal base for the NPDES (National Pollutant Discharge Elimination System) and the subsequent point source effluent guidelines and standards. The November 6, 1975 issue of the Federal Register published interim final rules for Best Practical Treatment levels for effluent discharges from ore mining and dressing operations. Litigation was immediately initiated by eleven companies against these proposed rules, and they are currently being reconsidered for reissuance in 1979. In 1974, the Federal Safe Drinking Water Act (Public Law 93-523) was enacted. A part of this legislation is the Underground Injection Congrol Program. The regulations implementing this program have undergone various public hearings and it is expected that they will be published in the Federal Register before the end of 1978. In 1975, the Texas Surface Mining and Reclamation Act (Senate Bill 55), providing for the Railroad Commission's authority to require reclamation of surface mines, was passed. In 1977, an amendment to Senate Bill 55 was introduced that proposed to place regulation of in situ mining of coal, lignite, and

Jan 1, 1979

By C. A. Hartinagel

During 1941, the total production of crude oil in New York state was 5,185,000 bbl. This represents a small increase over the average for the past five years. From 1921, when the annual production of the state amounted to only 988,000 bbl., there was a regular annual increase in production (excepting one or two years) until the 5,000,000-bbl. mark was reached in 1937, After more than 20 years of oil recovery by flooding methods, it was generally believed, until a few months ago, that the rate of production was nearly at its peak and within a few years the fields would experience a gradual decline as the thicker sands became exhausted and the thinner ones could be worked only at increasing costs. As a result of the present emergency, however, unusual efforts are being made, in spite of higher costs of operation, to increase the output of Pennsylvania grade oil, to which the New York product belongs. Since most of any increased production would be obtained by flooding, and since floods travel slowly, no large increase in production can be expected for some months to come. During the first year, 10 or 15 per cent increase could be obtained, but maximum production, an increase of perhaps 40 per cent, could not be expected until some time during the second or third year. In the Allegany fields, which account for two thirds of the state's oil production, 1246 wells, including water-intake wells, were drilled during the year; 390 more than in the preceding year and 590 more than in 1939. It is evident that much of the best oil territory has already been developed. As producers move toward edge properties and thinner sands, returns will be smaller, whereas costs remain the same or, under war conditions, become higher. It is estimated that at least 60 million barrels of oil is in sight and will be produced from the thicker sands by present recovery methods. In the thinner sands and edge properties, some 35 million additional barrels can be produced at a profit only if prices become higher. In view of the fact that there is little hope of finding new oil pools in New York, one of the future problems of the oil producer will be to obtain adequate returns for increased production costs. The year started with a posted price of $2.15 per barrel of crude. There were five successive price increases until the high of the year was reached at $2.98 on Aug. 14. Eight days later the Office of Price Administration directed that the price be reduced to the June level of $2.75 a barrel, which remained in effect to the end of the year. With rising costs of operation, it is feared that many of the smaller properties cannot continue production unless the Federal price cut is revoked. During the year, Allegany Refiners Inc., a local enterprise founded in 1933, with plant at Bolivar, western Allegany County, increased its refining capacity from 1000 to 1500 bbl. daily. At the same time equipment was added to make the plant a complete lubricating-oil refinery, including facilities for the refining of wax into the finished product. Previous to the enlargement, it was necessary to sell the wax

Jan 1, 1942

By C. A. Hartinagel

During 1941, the total production of crude oil in New York state was 5,185,000 bbl. This represents a small increase over the average for the past five years. From 1921, when the annual production of the state amounted to only 988,000 bbl., there was a regular annual increase in production (excepting one or two years) until the 5,000,000-bbl. mark was reached in 1937, After more than 20 years of oil recovery by flooding methods, it was generally believed, until a few months ago, that the rate of production was nearly at its peak and within a few years the fields would experience a gradual decline as the thicker sands became exhausted and the thinner ones could be worked only at increasing costs. As a result of the present emergency, however, unusual efforts are being made, in spite of higher costs of operation, to increase the output of Pennsylvania grade oil, to which the New York product belongs. Since most of any increased production would be obtained by flooding, and since floods travel slowly, no large increase in production can be expected for some months to come. During the first year, 10 or 15 per cent increase could be obtained, but maximum production, an increase of perhaps 40 per cent, could not be expected until some time during the second or third year. In the Allegany fields, which account for two thirds of the state's oil production, 1246 wells, including water-intake wells, were drilled during the year; 390 more than in the preceding year and 590 more than in 1939. It is evident that much of the best oil territory has already been developed. As producers move toward edge properties and thinner sands, returns will be smaller, whereas costs remain the same or, under war conditions, become higher. It is estimated that at least 60 million barrels of oil is in sight and will be produced from the thicker sands by present recovery methods. In the thinner sands and edge properties, some 35 million additional barrels can be produced at a profit only if prices become higher. In view of the fact that there is little hope of finding new oil pools in New York, one of the future problems of the oil producer will be to obtain adequate returns for increased production costs. The year started with a posted price of $2.15 per barrel of crude. There were five successive price increases until the high of the year was reached at $2.98 on Aug. 14. Eight days later the Office of Price Administration directed that the price be reduced to the June level of $2.75 a barrel, which remained in effect to the end of the year. With rising costs of operation, it is feared that many of the smaller properties cannot continue production unless the Federal price cut is revoked. During the year, Allegany Refiners Inc., a local enterprise founded in 1933, with plant at Bolivar, western Allegany County, increased its refining capacity from 1000 to 1500 bbl. daily. At the same time equipment was added to make the plant a complete lubricating-oil refinery, including facilities for the refining of wax into the finished product. Previous to the enlargement, it was necessary to sell the wax

Jan 1, 1942

By F. W. Apgar

THe valuable results that have followed the application in recent years of microscopic methods of research to problems of ore genesis have been significant, but possibly the recognition of their practical importance is not as general as might be, and while, as a scientific method of investigating ores and rocks, the advantage derived through the use of the microscope is unquestioned, its utility as an aid in solving mining problems arising during actual every-day mine examination and operation may not be fully appreciated. Perhaps the most logical method of showing some of these practical applications of the microscope will be to consider first the prospect stage of a mining venture, then the uses to which the instrument may be put during the operation of a working and developed mine, arid, finally, to discuss some of the problems of a metallurgical nature that may arise during milling and smelting the ore. The valuation of mining property as a preliminary to acquiring ownership or determining the advisability of investing time and money in an enterprise is one of the most important and delicate problems that come before the mining engineer. The many and variable factors that have to be taken into account, as, for example, the geology of the district, availability of supplies, probable mining costs, transportation facilities, and the quality of ore, require a careful balancing of costs against recoverable values. Primarily, however, a study of the local geology is of first importance, since, in a prospect with little development work, the question of character and probable quantity of the ore and its value can only be approximated with any degree of accuracy by a thorough investigation of geologic conditions, and a general knowledge of ore deposits. Unless these are favorable and pay ore reasonably certain, other factors need not be considered. The character of the outcrop, evidences of mineralizing agencies in the adjacent rocks, and geological structure, are the data of chief significance.

Jan 1, 1914

By A. J. Teplitz, J. K. Rodgers, E. M. Pohoriles

This note is presented in order to call attention to a newly developed laboratory apparatus that appears to have interesting possibilities for the study of lost circulation of the pressure-parting type, for a more realistic evaluation of sealing materials for this type of loss, and for investigation of other aspects of hydraulic fracturing. A study of lost circulation, conducted jointly by operating divisions of the Gulf Oil Corp. and the Gulf Research & Development Co., has been in progress for the past few years. Earlier phases of the study dealt with mechanical factors contributing to loss of returns in laminar type sediments.' One aspect of this type of loss which has been widely discussed in the literature and elsewhere concerns the geometry of the fractures into which such losses occur. This subject is not merely a philosophical one, but has an important bearing on procedures for combating lost circulation difficulties and on other well operations. The further course of the collaborative studies previously mentioned has produced some information on this subject which, though limited in amount, is believed to be significant. In several typical cases of lost circulation in laminated shale and sand formations, the wells have been surveyed with instruments2,3 capable of detecting the points of loss with considerable accuracy. These wells were located in the Gulf Coast of Texas and Louisiana, in the Texas Panhandle, and in the Rocky Mountain area. In each of these instances the loss was shown to be occurring at some distance removed from the bottom of the hole and sharply confined to a very narrow interval, less than 1 ft in thickness. It is rather difficult to imagine that fractures of a vertical nature' would be of the limited extent indicated by the surveys in these wells. Furthermore, the high rates of loss at relatively low pressure differentials observed in some of these instances together with the narrow intervals involved would appear to require the radial flow pattern which would be associated with a more or less horizontal fracture plane. In view of the foregoing observations and records of successful squeeze cementing operations, in attempting to construct a laboratory apparatus For simulating pressure induced lost circulation, it was decided that the design should be based on a horizontal type of fracture. It was realized that5,6 Vhe production of horizontal fractures in a formation with non-penetrating fluid requires some mechanism for transmitting vertical components of the hydraulic forces to the plane of parting. This was accomplished, as will be evident in the description of the apparatus that follows, by providing recesses in the wall of the borehole which are believed to be representative of wellbore configuration found in Gulf Coast wells. The possible influence of such borehole irregularities on both pressure fracturing and the treatment of lost circulation appears to have been neglected in many studies of these subjects. It is believed that the present apparatus, incorporating features that take into account some of the factors mentioned, will provide means of gaining a further understanding of pressure induced fracturing and possibly for more realistically evaluating the numerous sealing agents, particularly the non-time-setting materials employed in treating the pressure-parting type of loss. DESCRIPTION OF APPARATUS The test cell used in the laboratory investigations is shown in Fig. 1. A schematic diagram of the entire system is shown in Fig. 2.

Jan 1, 1956

By Thomas Fraser, H. F. Yancey

Prior to the war just ended, Germany was the greatest coal producer in continental Europe. In 1943 the production of coal, bituminous and higher in rank, together with brown coal calculated to the equivalent amount of bituminous coal, is estimated to have been about 240 million metric tons, according to the War Department. Before the war production in Germany exceeded consumption. No other country in continental Europe except Poland had a large surplus. However, England's surplus was the largest in Europe as a whole. Before World War II the Ruhr Basin normally supplied about 70 pet of the total production of high-rank coal, the Saar and Aachen about 6 pet each, Upper Silesia about 14 pet, and Silesia and Saxony the remainder. Nearly one third of the brown coal was produced in the Rhineland, a little less than one half in central Germany nest of the Elbe River, and about one fourth east of the Elbe. Bituminous coal and brown coal together constituted by far the most important energy resources of the old German Reich. Bituminous coal furnished nearly 70 pet of the total energy requirement, brown coal supplied about 25 pet, and water power, wood, petroleum and alcohol together aggregated only 7 pet. Because it was the most important single mineral resource of Germany, an excess of coal enabled the Reich to import nearly all the other mineral products that she lacked, such as iron ore from Lorraine. The area adjacent to the coal fields was supplied with gas from an interconnected grid. Similar electric grids are based on brown coal with the power stations at the mines. Coal tar provided the foundation for the development of the extensive German chemical industries as exemplified by the I. G. Farbenindustrie. For almost a century, German scientists have been adequately supported both by the State and by industry in studying improved methods of utilizing coal. In Germany the mineral rights were reserved by the State and ordered eatraction of coal was enforced. Each lease comprised a relatively extensive area. which accounts for the generally large size of the mines and mining companies In 1938 there were 160 mines in the Ruhr, with a total output of 125 million tons but 90 pet of the production was controlled by 20 companies. By far the largest single coal-mining company in Germany was the Gelsen-kirchener Bergwerke A. G., which produced nearly 27 million tons in the Ruhr in 1937. Second was Saargruben A. G. a State-owned company operating in the Saar, which produced 'lore than '3 million tons. Third was Bergwerksgesellschaft Hibernia A. G., with 10 million tons, also in the Ruhr. Briquettes are made from both bitumillous coal and brown coal, but in 1938 some 44 million toils of brown-coal bri-

Jan 1, 1947

By Thomas Fraser, H. F. Yancey

Prior to the war just ended, Germany was the greatest coal producer in continental Europe. In 1943 the production of coal, bituminous and higher in rank, together with brown coal calculated to the equivalent amount of bituminous coal, is estimated to have been about 240 million metric tons, according to the War Department. Before the war production in Germany exceeded consumption. No other country in continental Europe except Poland had a large surplus. However, England's surplus was the largest in Europe as a whole. Before World War II the Ruhr Basin normally supplied about 70 pet of the total production of high-rank coal, the Saar and Aachen about 6 pet each, Upper Silesia about 14 pet, and Silesia and Saxony the remainder. Nearly one third of the brown coal was produced in the Rhineland, a little less than one half in central Germany nest of the Elbe River, and about one fourth east of the Elbe. Bituminous coal and brown coal together constituted by far the most important energy resources of the old German Reich. Bituminous coal furnished nearly 70 pet of the total energy requirement, brown coal supplied about 25 pet, and water power, wood, petroleum and alcohol together aggregated only 7 pet. Because it was the most important single mineral resource of Germany, an excess of coal enabled the Reich to import nearly all the other mineral products that she lacked, such as iron ore from Lorraine. The area adjacent to the coal fields was supplied with gas from an interconnected grid. Similar electric grids are based on brown coal with the power stations at the mines. Coal tar provided the foundation for the development of the extensive German chemical industries as exemplified by the I. G. Farbenindustrie. For almost a century, German scientists have been adequately supported both by the State and by industry in studying improved methods of utilizing coal. In Germany the mineral rights were reserved by the State and ordered eatraction of coal was enforced. Each lease comprised a relatively extensive area. which accounts for the generally large size of the mines and mining companies In 1938 there were 160 mines in the Ruhr, with a total output of 125 million tons but 90 pet of the production was controlled by 20 companies. By far the largest single coal-mining company in Germany was the Gelsen-kirchener Bergwerke A. G., which produced nearly 27 million tons in the Ruhr in 1937. Second was Saargruben A. G. a State-owned company operating in the Saar, which produced 'lore than '3 million tons. Third was Bergwerksgesellschaft Hibernia A. G., with 10 million tons, also in the Ruhr. Briquettes are made from both bitumillous coal and brown coal, but in 1938 some 44 million toils of brown-coal bri-

Jan 1, 1947

By W. L. Worrell

R. C. Gifkins (CSIRO)—In this paper evidence is put forward to support the idea of grain boundary shearing in aluminum at 4.2°K and the phenomenon is explained in terms of a low-temperature "equicohesive temperature". It is stated that these findings show that grain boundary shear cannot be ruled out in any situation by temperature arguments alone. We believe, from our own recent study of "apparent grain boundary sliding'' at temperatures below 0.45 Tm, that it can be ruled out on temperature arguments alone.45 Our experiments were made principally with magnesium and a Ms-A1 alloy ("Magnox A12"). Careful examination of offsets of marker lines or steps at grain boundaries produced by deformation at room temperature (-0.3 Tm) showed many of these to result from curvature over narrow zones along the grain boundaries. A significant residuum did, however, appear as a sharp offset or step. It was found that the mean value of this step rose to a small value during the first 0.5 to 1 pct strain and then remained at this level with further strain. Moreover, exactly the same values were obtained (at the same stress) at 75°C instead of 21°C. That is, in this range of temperature the "apparent sliding" was not temperature-sensitive. At 125°C and above there was sliding which increased with strain and which was temperature-dependent. When this temperature-dependent sliding was used to calculate the sliding to be expected at room temperature, this underestimated the "apparent sliding" by a factor of 104. The conclusion drawn is that the "apparent sliding" consists of shear localized in a zone of a width measured perhaps in microns, whereas it seems that true sliding occurs on the boundary surface.46 A model for such localized shear has been developed in general terms, following a similar model of Urie and Wain.47 Other strong evidence for low-temper- ature sliding has been based on the offsets of marker lines consisting of a substructure seen using the electron microscope to resolve these.48 We have repeated this work and found that the effects can be accounted for in terms of cracks in an oxide film which is produced when the substructure is etched up; these cracks form over zones of shear rather than at actual interfaces. However, in aluminum at room temperature (-0.3 Tm) there is no "apparent sliding" which is optically detectable. We suggest that, when the temperature is much lower (and possibly the rate of strain higher, too), as in the experiments of Chin et al., then aluminum behaves like magnesium at room temperature, and a narrow zone of shear develops to accommodate differences in strain across the grain boundary. Such a zone could well give rise to triple-point cracks. It is hoped to investigate these suggestions further. B. Y. Chin, W. F. Hosford, Jr., and W. A. Backofen (authors' reply)—It is interesting to have Dr. Gif-kin's comments, although it is somewhat difficult to reply in detail without the reference containing the work that he describes. Apparently though, he does find a low-temperature temperature-independent sliding that would seem to be related to the observations reported here. Perhaps some of the difficulty has semantic origins, growing out of the distinction between ('true sliding" and "apparent sliding".

Jan 1, 1965

By L. C. Aycock, J. Hunter, P. M. Lyons

In view of the unfavorable discovery trend that has set in during the past few years, it seems permissible to infer that the large, more easily found crude reserves in Louisiana are now known. Without doubt, many new producing areas will be located, but in the light of development during the past few years the majority of new areas probably will be found at greater depths and from relatively poorer sands. f Although sufficient reserves exist in Louisiana to last at the present rate of production for a considerable period, additional reserves must be found in more intensive development of the presently known structures. In order to ensure the greatest ultimate recovery from such structures, the most advanced technical methods must be employed in their exploitation. Wherever possible, cycling and repressuring plants should be installed. 'here are presently in Louisiana, especially in south Louisiana, a great many fields that contain gas-condensate reservoirs. These reservoirs cannot be produced for their liquid hydrocarbon content under present conditions without wasting an enormous quantity of gas and creating underground waste. Although some of these reservoirs are being produced, such production must be considered in the nature of a salvage operation rather than as a sound economic proposition. Such reservoirs, however, can become profitable ven- tures through the use of cycling and repressuring plants. Cycling operations now operating in Louisiana have increased the ultimate recovery from gas-condensate reservoirs anywhere from 10 to 30 per cent. Cycling operations will also provide a considerable reserve of gas, without which Louisiana cannot hope to develop any program of industrialization. During the past year, Louisiana attained the rank of third among the oil-producing states of this country. With a proper program of exploitation and development, and with emphasis on conservation, Louisiana can maintain this position for a great many years. Production On Dec. 31, 1943, oil and/or gas were being. produced in 52 parishes, or 81 per cent of all the parishes in the state. Thirty-three of the parishes produced oil and gas, 14 produced oil, and 5 produced solely gas. Tensas Parish in north Louisiana and Assumption Parish in south Louisiana formerly contained no producing fields but during 1943 joined the ranks of the producing parishes. Twenty-three new fields, including one rediscovery, were found during 1943-—a rate of discovery almost comparable to that of the preceding year. Eleven of these new discoveries were either gas or gas-condensate fields. Thus, the trend of development in finding new reserves was also comparable to that of 1942. Many reasons of considerable merit have been advanced to account for the discouraging lack of crude-oil reserves found during the past year. None are, however, completely satisfactory.

Jan 1, 1944

By J. Hunter, P. M. Lyons, L. C. Aycock

In view of the unfavorable discovery trend that has set in during the past few years, it seems permissible to infer that the large, more easily found crude reserves in Louisiana are now known. Without doubt, many new producing areas will be located, but in the light of development during the past few years the majority of new areas probably will be found at greater depths and from relatively poorer sands. f Although sufficient reserves exist in Louisiana to last at the present rate of production for a considerable period, additional reserves must be found in more intensive development of the presently known structures. In order to ensure the greatest ultimate recovery from such structures, the most advanced technical methods must be employed in their exploitation. Wherever possible, cycling and repressuring plants should be installed. 'here are presently in Louisiana, especially in south Louisiana, a great many fields that contain gas-condensate reservoirs. These reservoirs cannot be produced for their liquid hydrocarbon content under present conditions without wasting an enormous quantity of gas and creating underground waste. Although some of these reservoirs are being produced, such production must be considered in the nature of a salvage operation rather than as a sound economic proposition. Such reservoirs, however, can become profitable ven- tures through the use of cycling and repressuring plants. Cycling operations now operating in Louisiana have increased the ultimate recovery from gas-condensate reservoirs anywhere from 10 to 30 per cent. Cycling operations will also provide a considerable reserve of gas, without which Louisiana cannot hope to develop any program of industrialization. During the past year, Louisiana attained the rank of third among the oil-producing states of this country. With a proper program of exploitation and development, and with emphasis on conservation, Louisiana can maintain this position for a great many years. Production On Dec. 31, 1943, oil and/or gas were being. produced in 52 parishes, or 81 per cent of all the parishes in the state. Thirty-three of the parishes produced oil and gas, 14 produced oil, and 5 produced solely gas. Tensas Parish in north Louisiana and Assumption Parish in south Louisiana formerly contained no producing fields but during 1943 joined the ranks of the producing parishes. Twenty-three new fields, including one rediscovery, were found during 1943-—a rate of discovery almost comparable to that of the preceding year. Eleven of these new discoveries were either gas or gas-condensate fields. Thus, the trend of development in finding new reserves was also comparable to that of 1942. Many reasons of considerable merit have been advanced to account for the discouraging lack of crude-oil reserves found during the past year. None are, however, completely satisfactory.

Jan 1, 1944

By C. S. Barrett, P. Coheur

AXnealing twins are common in the microstructure of copper that has been rolled and recrystallized. In such samples it follows that a twin relationship should exist between components of the re-crystallization texture,' and several examples of this have been reported. For example, twin relationships have been found in recrystallized electrolytic copper sheet, as indicated in Fig. I, from a paper by Coheur and Lejeune.2 In this pole figure the cube texture (100) [001] is indicated by the hollow squares in the lower half of the figure (the pole figure for 200 reflections) and in the upper, (III), part of the figure. The texture contains, in addition to this orientation, the first-order twins of it, shown in the figure by the filled triangles. This orientation relation has been suggested by others also, under certain annealing conditions,3'4 although pole figures have not been published to confirm it. Some orientations in recrystallized sheets are identical with their twins, because of the symmetry elements of the texture— this is true, for example, with the (113) [ZII] texture so commonly reported for brass—hence it appears impossible in such samples to decide whether the twin relationships result from twinning or merely from the symmetry of the deformation process. The present investigation of a commercial copper strip seems to yield an example in which annealing twins account unambiguously for the principal orientations present. It proves to be a case, also, for which the recrystallization texture cannot be viewed as derived from the deformation texture by a first or second-order twinning mechanism. Materials and Methods The samples investigated were of secondary copper (melted in belgium) to which 0.19 per cent iron had been added to raise the recrystallization temperature. How much the orientation characteristics of this metal can be ascribed to the iron content and how much to other impurities or to melting and pouring practice have not been investigated.* The rolling was done in one direction only, on a mill with rolls of about 20-cm diameter. A strip I. cm wide was reduced from 5 mm thickness to 0.05 mm by several cold passes at commercial speeds. The samples cut from this 99 per cent reduced strip were X-rayed throughout their entire thickness. A pole figure made soon after rolling and annealing was identical, within experimental error, with one that was made when a two-year interval occurred between rolling and annealing. X-ray patterns were made on a camera2 that traversed

Jan 1, 1947

By C. S. Barrett, P. Coheur

AXnealing twins are common in the microstructure of copper that has been rolled and recrystallized. In such samples it follows that a twin relationship should exist between components of the re-crystallization texture,' and several examples of this have been reported. For example, twin relationships have been found in recrystallized electrolytic copper sheet, as indicated in Fig. I, from a paper by Coheur and Lejeune.2 In this pole figure the cube texture (100) [001] is indicated by the hollow squares in the lower half of the figure (the pole figure for 200 reflections) and in the upper, (III), part of the figure. The texture contains, in addition to this orientation, the first-order twins of it, shown in the figure by the filled triangles. This orientation relation has been suggested by others also, under certain annealing conditions,3'4 although pole figures have not been published to confirm it. Some orientations in recrystallized sheets are identical with their twins, because of the symmetry elements of the texture— this is true, for example, with the (113) [ZII] texture so commonly reported for brass—hence it appears impossible in such samples to decide whether the twin relationships result from twinning or merely from the symmetry of the deformation process. The present investigation of a commercial copper strip seems to yield an example in which annealing twins account unambiguously for the principal orientations present. It proves to be a case, also, for which the recrystallization texture cannot be viewed as derived from the deformation texture by a first or second-order twinning mechanism. Materials and Methods The samples investigated were of secondary copper (melted in belgium) to which 0.19 per cent iron had been added to raise the recrystallization temperature. How much the orientation characteristics of this metal can be ascribed to the iron content and how much to other impurities or to melting and pouring practice have not been investigated.* The rolling was done in one direction only, on a mill with rolls of about 20-cm diameter. A strip I. cm wide was reduced from 5 mm thickness to 0.05 mm by several cold passes at commercial speeds. The samples cut from this 99 per cent reduced strip were X-rayed throughout their entire thickness. A pole figure made soon after rolling and annealing was identical, within experimental error, with one that was made when a two-year interval occurred between rolling and annealing. X-ray patterns were made on a camera2 that traversed

Jan 1, 1947

By K. H. Coats

In tnany oil and gas fields, significant investments are required in piping networks for collection, injection and disposal of various fluids. This paper treats the problem of optimally locating the trunkline(s) for a given systet to nlinimize both the total length of piping connecting the individual wells or lease batteries to the trunkline and the length of the latter. Single and multiple trunklines, varying line sizes, and grouping of wells are considered. Some attention is paid to the case of a curved trunkline. A field case is treated and conclusions are that the problem of locating a single trunkline is relatively straightforward while the location of multiple trunklines requires further research. INTRODUCTION la many oil and gas fields, significant investments are required in piping networks for collection, injection and disposal of various fluids. A single field may concurrently require piping systems for gathering of oil, gathering of gas, injection of water or gas and disposal of salt water. Two problems arise in the consideration of any one of these networks. The first involves the sizing of the various segments of the network to minimize piping and compression costs. The second problem, treated herein, is that of optimally locating the trunkline(s) for a given piping system to minimize the total length of pipe connecting the individual wells or lease batteries to the trunkline. This minimization problem may arise in field automation if it involves replacement of individual lease batteries by a central field battery which will require trunklines and connecting pipelines to individual wells. The problem also arises in connecting a gas pipeline through a subsidiary trunkline to wells in a gas storage field. The first analysis given below treats the case of a single trunkline and of separate connecting lines for all field units.* The analysis is then extended to consider multiple trunklines and common connecting lines for groups of field units. Varying sizes, and therefore costs, of the connecting lines are taken into account. A simplified development is given to illustrate the manner in which line sizing calculations may be integrated with the line placement problem. This study is primarily directed toward the placement of straight trunklines, although for certain field shapes or well distributions curved trunk-lines might be preferable. Some mathematical consideration is therefore given to the placement of a curved trunk-line in a field. The determination of optimal locations for two or more trunklines involves some difficulties which are discussed below. The need for further research in this area is emphasized. The problem of a single trunkline is solved in relation to an actual oil field. The problem of optimally locating two trunklines in the same field is also treated and the results are compared to the single-trunkline case. All calculations reported were performed on an IBM 7072 digital compker. The importance of right-of-way, roads and terrain in locating trunklines and connecting lines is realized. The present analysis is advanced on the premise that in planning piping networks one should start with the optimal conditions whenever possible and proceed therefrom.