Search Documents

By Sherwin F. Kelly, Bela Low, William B. Creagmile

Electrical methods and instruments for geophysical exploration have been almost exclusively applied, during these years of development of the art, by a few companies specializing in this field. The control of patents, the cost of the instruments and the general lack of published information on details of field procedure and office interpretation have given these owners a monopoly in carrying out electrical surveys. The development of the Megger Ground Tester1 seems likely to change this situation, and to enable mining engineers and geologists, without special training in geophysics, to carry out simple reconnaissance electrical surveys. Nevertheless, the need for such special training and experience in planning surveys and interpreting their results remains, and probably i always will remain, indispensable for a successful outcome. The unique thing about, the Megger Ground Tester, which gives rise to this hope for its general use, is its simplicity of operation. The four binding posts of the instrument are connected by insulated wires to four stakes driven into the ground at appropriate points. The crank of the Megger is then turned, and the resistance of the ground between the two inside stakes is read directly, in ohms, by the deflection of a pointer over a scale. The apparatus is shown in Fig. 1. Fundamentally, the principle of operation is that of determining the resistance of a four-terminal conductor, as applied by Frank Wenner to the measurement of earth resistivity. "A four-terminal conductor is a conductor provided with two terminals to which current leads may be connected and two terminals to which potential leads may be connected. The resistance of such a conductor is the difference in potential between the potential terminals divided by the current entering and leaving

Jan 1, 1932

By Charles E. Locke

The little stamp-mill in the mining laboratory of the Massachusetts Institute of Technology and the work done by it have been well described by Prof. R. H. Richards and E. E. Bugbee in a paper read at the Albany meeting of the American Institute of Mining Engineers, February, 1903.' As run for student class-work the mill contains a feeder, stamps, plate, and vanner. Results in the past indicate that the work of these machines is just as efficient as that of a regular mill handling the same class of ore. It has been the custom to obtain ore principally from Nova Scotia, mainly because it is the nearest source of supply, and also because there is a considerable saving in freight-cost as compared with other districts. The gold in Nova Scotia ores is notoriously coarse, and for this reason it is almost impossible to obtain satisfactory results by sampling and fire-assay, unless an extremely large lot of ore is crushed and all of the contained gold pellets are saved. A very interesting and most extraordinary example of this fact has been presented by a recent run in the Technology stamp-mill. Since the capacity of the mill is about 60 kg. per hr., and since in about 5-hr. run the students in any one section have an opportunity to make the necessary study of machines, it usually happens that several runs are made from one lot of ore. When the shipment is received it is first dried and weighed, put through the Blake breaker, set at 1 or 1.5 in., and the crushed product is piled in a cone on the sampling-floor. When the crushing is completed the ore is usually stored away in barrels for future use; it is aimed to have each barrel of

Jan 1, 1914

By J. Hunter

DuXing 1942, Louisiana attained the rank of fourth among the great oil-producing states of this country. Its present prominent position is the result of an orderly and systematic program of exploitation with emphasis on conservation. Even before the functioning of M-68, the Federal spacing order, development and production in Louisiana were regulated by various acts of legislation, the most recent of which and by far the most effective is Act 157 of 1940. Under the authority of this act, it has been possible for the Department of Conservation to hold many public hearings and thereby to secure data and evidence regarding the feasibility of issuing rules and regulations for development of various oil and gas fields in the state. As a result of information compiled at such public hearings, many orders have been issued by the Commissioner of Conservation that have in most cases provided reasonable solutions to the problems that arise in the exploitation and development of fields in this state. Probably one of the most effective powers granted the Commissioner of Conservation in the state of Louisiana has been the authority to provide for fieldwide unitiza-tion and pooling of condensate fields. This has led to the erection of huge cycling plants in Louisiana, which permit the most efficient recovery of the liquid content of the reservoirs, and further conserve most of the gas reserve that undoubtedly will be of considerable future value. Many months have passed since various orders of the Department of Conservation were put into effect, and all are accomplishing their purpose; namely, the elimination of waste. Although the effectiveness of these orders provides considerable satisfaction to the members of the Department of Conservation, it is also a tribute to the members of the oil and gas industry in Louisiana, who, in addition to providing carefully prepared technical data, have also given unstinting cooperation and have thereby enabled the Department to cope intelligently with the many problems. Production On Dec. 31, 1942, oil and/or gas was being produced in 50 parishes, or 78 per cent of all the parishes in the state. Thirty-three of the parishes produced oil and gas, 12 produced oil, and 5 produced solely gas. This is indeed an enviable record for any state. However, it is reasonable to assume that eventually all parishes in the state of Louisiana will be productive. From a geological viewpoint, there is no apparent reason to assume otherwise—a point that a11 operators seeking oil and gas production in this state may well bear in mind. Twenty new fields were found during 1942—a rate of discovery that does not compare favorably with the 30 new fields found during 1941. The record of discoveries in Louisiana during 1942 is further disappointing when it is realized that 8 of the 20 new fields discovered were gas fields. During this period of war emergency, there are, of course, many

Jan 1, 1943

By J. Hunter

DuXing 1942, Louisiana attained the rank of fourth among the great oil-producing states of this country. Its present prominent position is the result of an orderly and systematic program of exploitation with emphasis on conservation. Even before the functioning of M-68, the Federal spacing order, development and production in Louisiana were regulated by various acts of legislation, the most recent of which and by far the most effective is Act 157 of 1940. Under the authority of this act, it has been possible for the Department of Conservation to hold many public hearings and thereby to secure data and evidence regarding the feasibility of issuing rules and regulations for development of various oil and gas fields in the state. As a result of information compiled at such public hearings, many orders have been issued by the Commissioner of Conservation that have in most cases provided reasonable solutions to the problems that arise in the exploitation and development of fields in this state. Probably one of the most effective powers granted the Commissioner of Conservation in the state of Louisiana has been the authority to provide for fieldwide unitiza-tion and pooling of condensate fields. This has led to the erection of huge cycling plants in Louisiana, which permit the most efficient recovery of the liquid content of the reservoirs, and further conserve most of the gas reserve that undoubtedly will be of considerable future value. Many months have passed since various orders of the Department of Conservation were put into effect, and all are accomplishing their purpose; namely, the elimination of waste. Although the effectiveness of these orders provides considerable satisfaction to the members of the Department of Conservation, it is also a tribute to the members of the oil and gas industry in Louisiana, who, in addition to providing carefully prepared technical data, have also given unstinting cooperation and have thereby enabled the Department to cope intelligently with the many problems. Production On Dec. 31, 1942, oil and/or gas was being produced in 50 parishes, or 78 per cent of all the parishes in the state. Thirty-three of the parishes produced oil and gas, 12 produced oil, and 5 produced solely gas. This is indeed an enviable record for any state. However, it is reasonable to assume that eventually all parishes in the state of Louisiana will be productive. From a geological viewpoint, there is no apparent reason to assume otherwise—a point that a11 operators seeking oil and gas production in this state may well bear in mind. Twenty new fields were found during 1942—a rate of discovery that does not compare favorably with the 30 new fields found during 1941. The record of discoveries in Louisiana during 1942 is further disappointing when it is realized that 8 of the 20 new fields discovered were gas fields. During this period of war emergency, there are, of course, many

Jan 1, 1943

By L. T. Sanchez, W. T. Rogers

This paper presents the results of a production experiment evaluating the effect of the use of oxygen in the bessemer converter with respect to its relation to blowing time, amount of steel scrap or cold pig iron which can be melted and teeming temperatures of the molten steel. THE simplest and probably the most efficient and economical means for producing steel from molten pig iron is the bessemer converter. This process is essentially a mechanism for bringing oxygen into contact with the molten metal thereby oxidizing the elements silicon, manganese, and carbon. The source of oxygen is that contained in the air and is limited by that amount. In theory, there is an intermediate chemical reaction due to the mass action of iron and air which is represented by the equation: 2Fe + O2- = 2Fe0 The FeO then becomes the oxidizing agent and reacts with the silicon, manganese, and carbon to produce silicon dioxide (SiO,), manganese oxide (MnO), and carbon monoxide (CO), in the order mentioned. The balancing of the various chemical reactions shows that in the ordinary bessemer process more than sufficient oxygen is delivered to satisfy these reactions, which indicates that a further increase in the oxygen content of the air would serve no useful purpose. In spite of this reasoning, however, it will be demonstrated that when melting stelel scrap, commercially pure industrial oxygen introduced into the normal air blast will permit the melting of a larger proportion of steel scrap than is possible with air alone and also will increase the production rate by a substantial reduction in blowing time. It will also be shown that when melting cold pig iron, it is possible to melt up to twice as much pig iron with the use of oxygen as can be melted without added oxygen with a nominal increase in blowing time. At the plant where this study was made, oxygen is purchased from a nearby supplier and piped directly into the plant. It is supplied to the bessemer converter by being introduced directly into the blast line through an automatic control system which may be adjusted by the bessemer operator or "blower." Normally, iron is supplied by five blast furnaces to an open hearth shop containing twelve 165-ton capacity stationary furnaces and a bessemer converting shop having three 30-ton converters. The molten metal from the blast furnaces is allocated to one shop or the other in a manner to best provide for maximum production. At various times, it is desirable to direct the maximum amount of available blast furnace production to the open hearth shop. This has the effect of reducing the production of the bessemer shop. When this condition exists, it is desirable to supplement the reduced iron charge at the bessemer with steel scrap or cold pig iron to the maximum possible extent in order to maintain high total ingot production. This condition becomes aggravated when one of the blast furnaces is taken out of production for any repair job and particularly for extended periods such as when relining is necessary. The purpose of the investigation and experimentation with oxygen was to determine whether or not it would contribute to increased flexibility in the use of the raw materials, molten iron, steel scrap, and cold pig iron. In addition to the effect of oxygen on flexibility of operation, it was also necessary to determine the relation of its use to production rate or "blowing time," final finishing temperature of the steel or "teeming temperature," and steel quality.

Jan 1, 1953

By K. L. Temple, A. R. Colmer

ACID coal mine drainage presents a peculiarly difficult problem for two principal reasons. First is the fact that the amount of acid water discharged from active and abandoned mines constantly increases as coal fields are developed and thereby creates a steadily worsening nuisance of rapidly growing importance to the general public as well as to the coal industry. Second is the even more significant fact that there is no method yet known that will appreciably alleviate the acid water problem except at totally prohibitive cost to the coal operators. The problem is thus seen to be an urgent one. With a growing need for good quality water and a growing public demand for abatemknt of stream pollution, a large portion of the soft coal industry finds itself in the position of year by year dumping more and more acid into the streams and waterways and having no way in sight of improving the situation or even of keeping it from getting worse. While some studies have been made, it is only in the last few years that the problem has been seriously considered, chiefly by the group of workers under the direction of S. A. Braley at Mellon Institute and by the Bituminous Coal Research, Inc. fellowship at West Virginia University. Hinkle and Koehlerl reported the results of the earlier West Virginia work. This work pointed to certain biological aspects which had not been noticed previously. These may be summarized as two separate findings. One was that sulphur oxidizing bacteria were present in acid mine water and that their possible role in contributing to the acidity should be investigated. The other was

Jan 1, 1952

By W. M. Mobley

The coal industry in Alabama, centered in Birmingham, has pioneered coal-bene-ficiation practice in the United States. The nature of the coal seams and mining methods employed have necessitated use of equipment and methods best adapted to the local conditions. Although all of the 30 or more coal seams now being mined in the state receive beneficiation, only the three most important producers of coking coals, the Pratt, Mary Lee and Black Creek, are discussed in detail. Nature of the seams, washability characteristics and equipment used are given as examples of the extent of work and progress in this field. The coal seams in Alabama are relatively thin and pitching, making mining difficult and expensive. Most of them are characterized by thin partings of rock or shale in the seam itself, as well as laminations of bone and rash. Mechanical mining methods have increased the occlusions from roof and floor to such an extent that nearly all the coal mined in the state must receive some treatment before it can be put on the market. During the year ending Sept. 30, 1943,' 18,129,792 tons of coal were mined in the state and 14,364,177 tons, or 79.2 per cent, received treatment. Excluding from the total the 1,223,014 tons produced by small wagon mines and the hand-picked lump coal, the amount re- ceiving beneficiation would be more than 90.00 per cent. This is, by far, greater than in any other coal-producing state. The earliest record of coal beneficiation in Alabama was the installation in 1890 of an experimental Lurig washer by Alexander Cunningham, for the Sloss Iron and Steel Co. at its blast furnace in Birmingham.2 In 1894 the Jeffrey Manufacturing Co. introduced the English Robinson washer, a combination of a hydraulic classifier and centrifugal machine. Erskine Ramsay, who has contributed so much to the coal industry, saw its possibilities as well as its mechanical defects and soon had his inventive mind at work. He added a sludge tank of his own design, and many Robinson-Ramsay washers were installed in Alabama and other states. The Stewart jig appeared in 1900, followed by the Montgomery jig in 1910 and both have found extensive use. Increased interest in this field led to new designs, such as the American, Elmore, Burke and Faust. The first Baum-type Norton jig was operated in 1930 and within the last five years six large installations of this type have been made by the McNally-Pitts-burg, Jeffrey and Link-Belt Companies. Wet-washing tables were introduced in 1922 but not extensively used until recently. The two most popular types are the Deister-Overstrom and Deister Plat-O. The coal-cleaning equipment used in Alabama has been relatively simple, yet efficient, but as the amount of impurities in the raw coal has been increased by mechanical mining and labor costs have become higher, much interest has been shown in sand cones, froth flotation and

Jan 1, 1947

By W. M. Mobley

The coal industry in Alabama, centered in Birmingham, has pioneered coal-bene-ficiation practice in the United States. The nature of the coal seams and mining methods employed have necessitated use of equipment and methods best adapted to the local conditions. Although all of the 30 or more coal seams now being mined in the state receive beneficiation, only the three most important producers of coking coals, the Pratt, Mary Lee and Black Creek, are discussed in detail. Nature of the seams, washability characteristics and equipment used are given as examples of the extent of work and progress in this field. The coal seams in Alabama are relatively thin and pitching, making mining difficult and expensive. Most of them are characterized by thin partings of rock or shale in the seam itself, as well as laminations of bone and rash. Mechanical mining methods have increased the occlusions from roof and floor to such an extent that nearly all the coal mined in the state must receive some treatment before it can be put on the market. During the year ending Sept. 30, 1943,' 18,129,792 tons of coal were mined in the state and 14,364,177 tons, or 79.2 per cent, received treatment. Excluding from the total the 1,223,014 tons produced by small wagon mines and the hand-picked lump coal, the amount re- ceiving beneficiation would be more than 90.00 per cent. This is, by far, greater than in any other coal-producing state. The earliest record of coal beneficiation in Alabama was the installation in 1890 of an experimental Lurig washer by Alexander Cunningham, for the Sloss Iron and Steel Co. at its blast furnace in Birmingham.2 In 1894 the Jeffrey Manufacturing Co. introduced the English Robinson washer, a combination of a hydraulic classifier and centrifugal machine. Erskine Ramsay, who has contributed so much to the coal industry, saw its possibilities as well as its mechanical defects and soon had his inventive mind at work. He added a sludge tank of his own design, and many Robinson-Ramsay washers were installed in Alabama and other states. The Stewart jig appeared in 1900, followed by the Montgomery jig in 1910 and both have found extensive use. Increased interest in this field led to new designs, such as the American, Elmore, Burke and Faust. The first Baum-type Norton jig was operated in 1930 and within the last five years six large installations of this type have been made by the McNally-Pitts-burg, Jeffrey and Link-Belt Companies. Wet-washing tables were introduced in 1922 but not extensively used until recently. The two most popular types are the Deister-Overstrom and Deister Plat-O. The coal-cleaning equipment used in Alabama has been relatively simple, yet efficient, but as the amount of impurities in the raw coal has been increased by mechanical mining and labor costs have become higher, much interest has been shown in sand cones, froth flotation and

Jan 1, 1947

By John W. Cabot

THE following series of analyses, which may, be of interest to Bessemer-steel makers, is submitted as a contribution to the much-vexed discussion of manganese in Bessemer steel. They were made by the writer in the spring of 1881, at the works of the Pittsburgh Bessemer Steel Company Limited, during a period of about eight days, part of, which time the rail-steel showed great variation in rolling qualities. During the first part of the time in question, it rolled well; later on it began to roll worse until, finally, it cracked very badly, reaching its worst stage. After this it rapidly improved until it again rolled smoothly. During this .time of transition 'from. good rolling to bad, and back to good again, the course of the manganese was followed' quite closely. It is the striking correspondence between these varying manganese contents and the differences in rolling which is here presented as worthy of notice. The other ordinary elements were determined occasionally, but showed no unusual variation Tim steel, in question, was ordinary rail-steel of about "the following composition : C=.35.P=.08.Mn=.98. Si=.08. S=.05. The samples for manganese determinations were taken at first from an average of two days' work, and later on, when the steel

Jan 1, 1882

By Carville E. Sparks, Rollin Farmin

TRIAL installations of rock bolts, of the slit-rod- and-wedge type, were under way at several units of Day Mines, Inc., when Korean hostilities interrupted the already slow deliveries of steel bars to the Coeur d'Alene district. Factory-made bolts had not yet been put on the local market, so the program was halted for lack of supplies. Interest was revived by a visitor's description of wooden roof bolts. These were said to have been used briefly with apparent success in a coal mine, until apprehension voiced by the U. S. Bureau of Mines caused the practice to be suspended

Jan 9, 1953

Edwin H. MessiteR, New Pork City (communication to the Secretary*):—Under the heading " Flues," Mr. Edwards refers to the Bee-hive construction, a cross-section of which is shown in Fig. 4 of his paper. A flue similar to this was designed by me about six years ago,' in which the walls though much thinner than those described by Mr. Edwards gave entire satisfaction. These walls, from 2.25 in. thick throughout in the smaller flues, to 3.25 in. in the larger, were built by plastering the cement mortar on expanded-metal lath without the use of any forms, or cribs, whatever, at a cost of labor generally less then $1 per sq. yd. of wall. Of course, where plasterers cannot be obtained on reasonable terms, the cement can be molded between wooden forms, though it is difficult to see how it can be done with an interior core only as stated by Mr. Edwards. In regard to the effect of sulphur dioxide and furnace-gases on the cement, I have found that, in certain cases, this is a matter which must be given very careful attention. Where there is sufficient heat to prevent the existence of condensed moisture inside of the flue, there is apparently no action whatever on the cement, but if the concrete is wet, it is rapidly affected by these gases. At points near the furnaces there is generally sufficient heat not only to prevent internal condensation of the aqueous vapor always present in the gases, but also to evaporate water from rain or snow falling on the outside of the flue. Further along, a point is reached where rain-water will percolate through minute cracks caused by expansion and contraction, and reach the interior, even though internal condensation does not occur there in dry weather. From this point to the end of the flue the roof must be coated on the outside with asphalt paint or other impervious material. In very long flues a point may be reached where moisture will condense on the inside of the malls in cold weather. From this point to

Jan 1, 1905

By P. R. Kneitz, G. Yoshikado, D. Zayakov

The design and analysis of a circular, domed powerhouse for Pacific Gas and Electric (PG&E) Company's Kerckhoff 2 Project is described. Exploration, geologic stress determinations, mechanical properties, reinforcement and instrumentation are addressed briefly. The analyses of the circular, domed cavern and the comparison of predicted and field deformations are presented in somewhat more detail. The behavior of the completed powerhouse cavern has been found to be substantially as predicted by the analysis.

Jan 1, 1982

THE subcommittee on Coal Mining, since its appointment, has been engaged in collecting data about subsidences in coal mines in this country, and it now feels that almost all of the available data about occurrences of this sort in bituminous mines has been collected. As most of the bituminous seams are nearly level, the records obtained give the problem in its simplest form, without complications due to the pitch of the seam. Similar data is being compiled for the anthracite regions and it is hoped that this will be ready for the 1927 meeting. Copies of the questionnaire, Appendix A, were mailed to all of the coal operators' associations, to most of the large operating companies and to many engineers, with the request that any data on the subject be returned to the committee, or that advice of any subsidences known be given. The replies to most of the questionnaires were general only, although some specific cases were given. Many of the companies were unable to reply to all questions, as they lacked the necessary data, but in nearly every case where accurate data was available, it was cheerfully furnished, and any additional information requested was secured. All specific cases of subsidence were followed up by correspondence, and in several cases by personal inspection. Figs. 1 to 31 were made from the information furnished. Table 1 gives measurements of elevations taken in one case at intervals from October, 1913, to May, 1918. With one exception, where the evidence cannot yet be released on account of a lawsuit, it is believed that the cases submitted with this report include practically all that have happened in bituminous coal mining in this country of which actual measurements were secured. Some of these have already been published in the excellent report by Young and Stoek,1 and some instances have been secured from other publications. In collecting these data, the subcommittee had the Engineering Societies Library extend the bibliography given in the bulletin mentioned above to date. This list is given in Appendix B.

Jan 2, 1926

By R. F. Krueger, L. C. Vogel

A design is presented for an electrical analog computer which can solve non-steady state heat transfer problems in an extensive radial forrnation containing a moving cylindrical source. The computer is used to simulate a .simplified thermal oil recovery process in which heat transfer from a moving, constant temperature source takes place radially by conduction only. Temperature distribution curves are .shown for several different assumed modes of travel for the heat source. The data are used to estimate the residual fuel requirements necessary to maintain a self-propagating isotherma1 front for the particular system being studied. Although the computer is designed to represent an unique system. conversion factors can he adjusted to show the effects of changing the assumed values of system constants, such as thermal conductivity of the formation and temperature of the source isotherm. Examples are given to illustrate the relative influence the assumed values of these variab1es will have upon the quantity of fuel required to maintain the source. The maximum effect of heat transfer by the flowing air stream is estimated mathematically, and full requirements for this system are shown to he markedly reduced. Inasmuch as the examples discussrd refer to a simplified process, the results are not directly applicable to a practical field operation. It is believed, however, that the data il1ustr-ate some general trends which are important in thermal recovery processes. Data from laboratory and field experimentation can he used to modify the computer to take into account the influence of heat transfer by various mechanisms, for example, by injected air and by fluids ahead of the hot zone. With .such refinements it would be possible to estimate more accurately the limiting values for the rate of travel of the high temperature front and for the required air- injection rates. Use of this computer should aid in evaluating the economic feasibility of oil recovery by various thermal processes. It is hoped this paper will stimulate further work by others to help accomplish this objective. As the costs of exploration for and development of new oil fields rise. increasing the recovery of oil from established fields becomes more and more important. In fields containing low gravity crude oil, ultimate recoveries by primary means are sometimes less than 10 per cent and often total only 10 to 20 per cent of the oil in place. Conventional secondary recovery methods are not always effective in increasing this total. Methods which have been proposed for increasing the recovery of viscous oils include thermal processes for increasing the mobility of the oil. One method is to provide a moving heat source generated within the formation to heat the oil and a flowing gaseous medium (for example, air) to sweep the oil to the producing wells. The possibility of such a process has intrigued engineers for many years.'. '." but little or no information has been available in the literature relative to the technical or economic feasibility of this method. Recently, however, interest has been revived by publication of laboratory and field test results indicating the feasibility of maintaining

Jan 1, 1956

By W. A. Wood, W. H. Reimann, Maria Ronay

The basic mechanism of fatigue is studied in annealed a brass subjectecl to alternating torsion at room temperature, 100°, 200°, 300°, and 400°C, and in air. It is shown that the slip-zone micro-cracking which characterizes fatigue damage produced by small amplitudes at room temperature is progressively replaced by grain boundary cracking at elevated temperatures, replacement being complete at 400°C. Replacement occurs not because slip activity decreases hut because slip movements at elevated temperatures cease to concentrate in narrow zones and instead disperse. Decrease of amplitude at 400°C through permitting longer lives of specimens before fracture actually causes in- MOST studies of fatigue at elevated temperature have been concerned with data for design. Observations on the basic mechanism of fatigue have been largely incidental, though they have led to the interesting inference that this mechanism has features in common with that of creep.' This paper is concerned primarily with the mechanism itself. Advantage has been taken of mater- crease in pain boundary damage, an anomaly attributed to the greater difficulty at elevated tempwature of starting and propagating a crack. Surface corrosion was most pronounced along slip bands but since at elevated temperatures the slip hands showed no cracking the surface corrosion did not appear to influence onset and early spread of fatigue damage. Similarly the type of fatigue damage produced at room temperature by cyclic strain at large amplitudes, characterized by irregular mi-crocracks at zones between disoriented regions in a grain, was also replaced by mainly grain boundary cracking at elevated temperature, though not so completely. ials and procedures known to show readily how fatigue affects the microstructure of a metal at room temperature, so that direct comparison might be made with what the same procedures show when the material is subjected to fatigue deformation at higher temperatures. 1) MATERIAL This was 70/30 a brass, used extensively in previous studies at room temperature.' Specimens were turned from extruded rod to have parallel test portions 1-1/4 in. long and 7/32 in. diameter, annealed to a grain size -1/10 mm, and electro-

Jan 1, 1965

By P. E. Fitzgerald, Dana G. Hefley

An apparatus has been developed which permits selective acidizing of producing formations and determination of the relative permeability of a formation by fluid injection. This apparatus, known as the "Electric Pilot," is an electrical fluid-interface locator, the electrical circuit of which is completed when the elec-tcodes in the well are in contact with a conductive fluid, but is not completed when immersed in a nonconductive fluid. Results are given for a number of typical acidizing applications in which the interface locator was used to control the acid. Description of the method used in making a permeability survey and the data obtained are also included. Introduction Early in the development of the acidizing industry it was recognized that one of the most important problems to be solved in the chemical treatment of any well was the determination of what part of the exposed section in the well should be treated and the selection of the technique that would insure treatment of the desired section. One of the first techniques adopted for assisting in proper placement of the acid, which is still widely used, is the method of confining the acid to the producing section by means of a column of oil, which is known as the Carr1 method of treatment, named for its inventor. In the Carr method it is not possible to selectively acidize a specific horizon in a multiple pay zone, so many improvements and modifications of the basic Carr technique were devised to accomplish this result. In order to overcome the possibility of the acid entering an undesirable section at the bottom of the well, organic gel plugs2 were introduced into the bottom of the well, which served to halt the entrance of the treating solution into these zones.3 These chemical gels later liquefied because of bacterial action and were removed from the well with the produced fluid. In fields where a gas cap existed, as in the Goldsmith field of Ector County, Texas) it was imperative that a treating technique be evolved that would confine the acid to the oil-producing zone below the gas cap. By so doing the oil-productive capacity of the wells could be improved without greatly increasing the gas production and this would lower the gas-oil ratio of the well. ~h, technique employed4 to achieve this effect utilized two pumps, one for pumping the chemicals down the tubing, the other to simultaneously force oil down the annular space to confine the acid to the oil pay, thus preventing the chemicals from entering the upper gas-bearing zones. Experience has indicated that gas wells and certain types of oil wells respond better to ''stage treating.'' This technique utilizes the introduction of a certain volume of acid and then allows the well to ''clean up99 before introduction of the next and usually successively larger stages. Where such methods are employed steps must be taken to keep a disproportionate share of the acid from entering the most permeable and previously treated Zones. A special tool

Jan 1, 1944

By P. E. Fitzgerald, Dana G. Hefley

An apparatus has been developed which permits selective acidizing of producing formations and determination of the relative permeability of a formation by fluid injection. This apparatus, known as the "Electric Pilot," is an electrical fluid-interface locator, the electrical circuit of which is completed when the elec-tcodes in the well are in contact with a conductive fluid, but is not completed when immersed in a nonconductive fluid. Results are given for a number of typical acidizing applications in which the interface locator was used to control the acid. Description of the method used in making a permeability survey and the data obtained are also included. Introduction Early in the development of the acidizing industry it was recognized that one of the most important problems to be solved in the chemical treatment of any well was the determination of what part of the exposed section in the well should be treated and the selection of the technique that would insure treatment of the desired section. One of the first techniques adopted for assisting in proper placement of the acid, which is still widely used, is the method of confining the acid to the producing section by means of a column of oil, which is known as the Carr1 method of treatment, named for its inventor. In the Carr method it is not possible to selectively acidize a specific horizon in a multiple pay zone, so many improvements and modifications of the basic Carr technique were devised to accomplish this result. In order to overcome the possibility of the acid entering an undesirable section at the bottom of the well, organic gel plugs2 were introduced into the bottom of the well, which served to halt the entrance of the treating solution into these zones.3 These chemical gels later liquefied because of bacterial action and were removed from the well with the produced fluid. In fields where a gas cap existed, as in the Goldsmith field of Ector County, Texas) it was imperative that a treating technique be evolved that would confine the acid to the oil-producing zone below the gas cap. By so doing the oil-productive capacity of the wells could be improved without greatly increasing the gas production and this would lower the gas-oil ratio of the well. ~h, technique employed4 to achieve this effect utilized two pumps, one for pumping the chemicals down the tubing, the other to simultaneously force oil down the annular space to confine the acid to the oil pay, thus preventing the chemicals from entering the upper gas-bearing zones. Experience has indicated that gas wells and certain types of oil wells respond better to ''stage treating.'' This technique utilizes the introduction of a certain volume of acid and then allows the well to ''clean up99 before introduction of the next and usually successively larger stages. Where such methods are employed steps must be taken to keep a disproportionate share of the acid from entering the most permeable and previously treated Zones. A special tool

Jan 1, 1944

By Warren B. Weeks

The development of the relatively deeper fields discovered during 1937 helped build the 1938 production to 18,456,760 bbl., an increase of 6,295,910 bbl., or 51.6 per cent over 1937, and the largest production for south Arkansas since 1930. Schuler and Rodessa accounted for the increased production as well as for over half of the wells drilled in the state. There were 243 holes drilled during 1938, of which 200 were completed as oil or gas wells. Of the 29 wildcat wells completed, 25 were dry, 3 found oil in the Smack-over limestone, while 1 made a small oil well in the Nacatoch sand. This was less than half the number of wildcats drilled the previous year, but nearly twice as many field wells were drilled. The old depth record of 7973 ft. was exceeded twice during the year, with the present record of 8332 feet. Trend of Prospecting The porous "Reynolds" oolite of the Smackover limestone1 has been the object of most of the wildcat prospecting during the past two years. Seismograph work, which brought 22 crews into this area during 1938, was largely pointed toward a study of the structure of this limestone formation. Thirteen dry wildcats have been drilled to this formation and five pools have been opened in it since it was first found to be productive at Snow Hill in the spring of 1936. With the failure of "updip" prospects to produce, activity moved southward and basinward. Success in five instances in Columbia and south Union Counties has spurred activity in this area. Much of the acreage is under lease and half a dozen deep limestone tests are assured for the current year. Fig. 1 shows the location of the principal oil fields in south Arkansas, as well as one or two minor producing areas. The fields are numbered in the order of their discovery. It is shown that most of the recent discoveries are from the deeper formations. Dry wildcats that penetrated

Jan 1, 1939

By Warren B. Weeks

The development of the relatively deeper fields discovered during 1937 helped build the 1938 production to 18,456,760 bbl., an increase of 6,295,910 bbl., or 51.6 per cent over 1937, and the largest production for south Arkansas since 1930. Schuler and Rodessa accounted for the increased production as well as for over half of the wells drilled in the state. There were 243 holes drilled during 1938, of which 200 were completed as oil or gas wells. Of the 29 wildcat wells completed, 25 were dry, 3 found oil in the Smack-over limestone, while 1 made a small oil well in the Nacatoch sand. This was less than half the number of wildcats drilled the previous year, but nearly twice as many field wells were drilled. The old depth record of 7973 ft. was exceeded twice during the year, with the present record of 8332 feet. Trend of Prospecting The porous "Reynolds" oolite of the Smackover limestone1 has been the object of most of the wildcat prospecting during the past two years. Seismograph work, which brought 22 crews into this area during 1938, was largely pointed toward a study of the structure of this limestone formation. Thirteen dry wildcats have been drilled to this formation and five pools have been opened in it since it was first found to be productive at Snow Hill in the spring of 1936. With the failure of "updip" prospects to produce, activity moved southward and basinward. Success in five instances in Columbia and south Union Counties has spurred activity in this area. Much of the acreage is under lease and half a dozen deep limestone tests are assured for the current year. Fig. 1 shows the location of the principal oil fields in south Arkansas, as well as one or two minor producing areas. The fields are numbered in the order of their discovery. It is shown that most of the recent discoveries are from the deeper formations. Dry wildcats that penetrated

Jan 1, 1939

By J. R. Bell, W. J. Childs, J. H. Bucher, G. A. Wilber

A technique for determining recrystallization times as short as 0.10 sec was developed utilizing the "Gleeble", a commercially available testing system designed for the study of short-time, high-temperaLure themal and mechanical processes. The procedure consisted of heating a small tensile specimen to a given temperature of hot deformation, loading to a given reduction in area, unloading, delaying various intervals at temperature, and then reloading- to failure. The magnitude of the ultimate load obtained upon reloading decreased with delay lime as recrys-lallization proceeded. The technique was applied to austenite recrystallization in AISI 1010 and AISI 1010 uith 0.02 pct Cb steels. For each steel the reduction in area given the specimen on the first pull was mainlairred at 30 ± 5 pct and recrystallization times deterntined at various temperatures. The results indicaled a significantly slower rate of recrystallization for the columbium-modified composition, suggested the presence of- a recovery stage in the softening process , and indicated a greatly increased softening rate at a temperatuve where significant allotropic transformation to a partially ferritic Structure could occur. In recent years increasing attention has been paid to the fact that the process of recrystallization of austenite deformed at elevated temperatures is far from instantaneous at many practical hot-working temperatures.1-3 This realization has given rise to such terms as hot cold-working1 or warm-working,2 These terms generally describe processes where the recrystallization rate at the temperature of deformation is slow enough to have an appreciable effect on mechanical properties despite a relatively high deformation ternperature. The mechanical properties of interest can be either the properties at the deformation temperature as in hot-workability studies4 or the room-temperature properties after cooling as in the many recent studies of various thermomechanical processes172 where heat treatment and deformation are intentionally combined to give a unique set of room-temperature properties. Because of this interest in processes where the austenite recrystallization kinetics can be an important variable, the development of quantitative methods of following the course of short-time, high-temperature recrystallization has received increasing attention.l,3,5 The experimental methods to date have, in general, relied upon rapidly deforming the austenite, holding at temperature for various brief intervals, quenching as G.A.WILBER and W. J. CHILDS, Members AIME,are Research-Fellow and Professor, respectively, Rensselaer Polytechnic Institute, Troy, N. Y. J. R. BELL and J. H. BUCHER, Member AIME, are Research Engineer and Research Supervisor, respectively, Graham Research Laboratory, Jones & Laughlin Steel Co., Pittsburgh, Pa. Manuscript submitted March 13, 1968. IMD. rapidly as possible, and then using room-temperature measurements to follow the recrystallization process. Although such methods can be successfully applied to certain alloy steels, the existence of the allotropic transformation during cooling of plain-carbon or low-alloy steels tends to obscure the results. Thus, such room-temperature measurements as hardness and X-ray line widths do not correlate well with the extent of austenite recrystallization before quenching,5 and results based on room-temperature microstruc-tural observations are dependent upon the success in correlating the observed structure with the prior aus-tenitic grain structure.1,3,5 The purpose of the present work was to develop a quantitative method for the determination of short-time, high-temperature recrystallization rates, based on measurements made at the temperature of deformation. EXPERIMENTAL TECHNIQUE The basic technique consisted of heating a small tensile specimen to a given temperature of hot deformation, loading to a given reduction in area, unloading, delaying various intervals at temperature, and then reloading to failure. The data were obtained in the form of traces of load and elongation as a function of time. Due to the high deformation temperature, the strain hardening introduced during initial loading was progressively annealed out with holding time after unloading and the loads obtained upon reloading decreased as this softening proceeded. Although the value of the second load at any Consistent point On the load-elongation curve could have been used as a measure of the degree of softening, the most convenient to use was the ultimate load. The softening indicated by the decrease in the second ultimate load with time is essentially a process of annealing of cold-worked material at a high deformation temperature. Although some recovery grain growth may contribute to such a softening process, it is generally considered that the major softening which must take place to achieve complete removal of substantial Strain hardening will occur by the formation of new, stress-free grains. As the results of this work indicate that essentially complete removal of strain hardening did in fact occur. the primary softening process will be attributed to recrystallization, and specific reference made where it appears that other mechanisms may be contributing to the total observed softening. It would, of course, be of interest to attempt to correlate the results of this work with the actual austenite fraction recrystallized as determined by other techniques. This was not attempted in the present work because it would have required running a large number of additional specimens and, as discussed previously, there is limited assurance that the results would accurately reflect the prior austenite fraction recrys-

Jan 1, 1969