Search Documents

By M. A. Grossman

The harden ability of most steels can be predicted within 10 to I5 per cent provided the complete chemical composition is known, including "incidental" elements; and provided the as-quenched grain size is known; and provided, finally, that the composition and heating temperatures for hardening are such as to result in austenite free from carbide particles. In the method proposed herein, the steel is considered as having a base hardenability due to its carbon content alone (the hardenability of a "pure steel" of the given carbon content, without any other elements), and this base hardenability is multiplied by a multiplying factor for each chemical element present. After multiplying all these together, the final product is the hardenability. Grain size may be taken into account either in the base hardenability or after the multiplication. Hardenability is stated in terms of "ideal critical diameter", namely, the diameter of bar, in inches, that will just harden all the way through (absence of un-hardened core) in an "ideal" quench, and the calculation may also be related to the Jominy test The data bring out certain features rather clearly. For example: i. It is quite useless to attempt to predict hardenability unless all elements, including "incidentals,,) are known; thus an "incidental,, chromium content of 0.20 per cent increases the hardenability by about 50 per cent. 2. The relative effectiveness of different alloys is sometimes unexpected; thus molybdenum when calculated in this way appears to be of the same order of effectiveness as manganese, rather than much more powerful, as would appear to be common experience; observe that an increase from no manaanese to 0.20 per cent Mn provides a multiplying factor of 1.67, and an increase from no molybdenum to 0.20 per cent Mo provides a factor of 1.63, an increase of over 60 per cent in each case. However, if to a steel containing 0.50 per cent Mn there is added "20 points of manganese," the factor is raised from 2.65 (for 0.50 per cent Mn) to 3.35 (for 0.70 per cent Mn), or an increase of only 26 per cent. Thus the fist small addition of an element has a much more powerful percentage effect than an equal further addition when some is already present, and in most cases the effect of molybdenum is considered in relation to a steel in which molybdenum is absent. 3. If two elements are equally effective, a greater hardenability will be obtained by using, for example, 0.5 per cent of each than by using I.o per cent of either of them alone. 4. A knowledge of the as-quenched grain size is essential for precise work, since a difference of only one grain size number (say No. 7 instead of No. 6) makes a difference of almost 10 per cent in hardenability (in these units); this, however, does not apply to certain It should be emphasized that in chromium steels (over 0.30 per cent Cr) and chrome-molybdenum and chrome-vanadium steels, un-dissolved carbides are likely to be present in the steel as quenched, and that in such cases the charts can indicate only a maximum Passible hardenability, whereas the extent of hardening actually obtained may be much less. Thus tests on a number of chrome-molybdenum steels have indicated a degree of hardening amounting to only 50 to 65 per cent of the maximum possible, and in chromium steels from full hardening (100 per cent) down to as low as 70 per cent. On the other hand, when the amount of such elements is small (Cr under 0.30 per cent, Mo up to 0.25 per cent in the

Jan 1, 1942

By C. Wachmann

The theory presented ill this paper makes possible examination of the phenomenological aspect of secondary oil recovery by alcohol flooding. Limitutions of the theory are contingent on three primary assumptions: (1) chemical equilibrium, (2) no fingering, and (5) no dispersion. The second assumption implies one-dimensional flow. In a geometric sense the theory extends the Buckley-Leverett construction to systems of two slightly miscible fluids and to systems of three components. This is made possible by considering single-phase fluids to be made up two phases, namely of an excess of one phase and a negative amount of the other phase. The procedure is discussed in the paper. The theory also permits direct determination of the relationship between the aqueous phase saturation and the concentration of water in the aqueous phase in a zone of variable composition. The velocity of planes of constant water concentration and of constant saturation can be computted likewise and the existence of saturation discontinuities inferred. Consequently the behavior of such a Zone, which may exist at some time between a displaced and a displacing fluid, May be determined. mathematical details are given in Appendices. Problems of experimental verification are pointed out on the basis of a supporting experiment. Implications of the theory and effects of violations of primary assumptions are discussed briefly. The major conclusion is that, if the primary assumptions are met, with pure alcohol and alcohol-rich .slugs piston-like displacement of oil and water is possible. INTRODUCTION The recovery of oil from porous media by alcohol displacement has been studied for several years. Extensive experimental investigations into alcohol flooding have been carried out in the laboratory although little has been done in the field. A large amount of practical information is available, the extent being indicated by the first three papers cited 1-3 and their respecrive bibliographies. This has permitted the Formulation of inferential theories. A more analytical approach in which theories are developed primarily by reasoning from known physical principles and relationships has, however, lagged behind. In fact, an analytically derived theory of alcohol displacement has not been available. The theory presented in this paper on oil and water displacement by alcohol from a porous medium is a result of the analytical approach. The theory is idealized, as certain assumptions had to be made to make the mathematics tractable and reduce complexity of argument. In particular, major assuptions concerning conditions of equilibrium, interfacial stability, longitudinal mixing, etc., led to the exclusion of fingering, for example, from all considerations. In many laboratory experiments reported in the literature fingering could not be avoided. There is, therefore, disagreement between theories based on experimental evidence available and the analytically derived theory presented here. This theory presented is based on known physical data and makes use of the Buckley-Leverett construction and its suggested extension. The mathematical derivation of the theory is given in Appendices. Three examples relevant to alcohol displacement are discussed to explain the use of this theory: (1) system of two immiscible fluids (the Buckley-Leverett case); (2) system of two slightly miscible fluids involving an extension of the Buckley-Leverett construction; and (3) system of three components, including injection of pure alcohol or alcohol-rich fluid as a special case, which involves a more general extension of the Buckley-Leverett construction. In these discussions strict assumptions were made to impose equilibrium conditions and exclude mixing and fingering. Effects of relaxing these assumptions and consequent extensions of the theory are indicated. The complexity of the alcohol displacement process makes experimental verification of the theory essential. Some relevant evidence is offered in this paper.

Jan 1, 1965

By F. N. Speller

ASIDE from the Tuesday symposium on gases in metals, the Iron and Steel Division swung into action for the first time on the third day of the meeting with a discussion of iron and steel alloys. Dr. E. S. Davenport opened the discussion on Wednesday morning by presenting the paper written by himself in association with E. C. Bain and W. S. N. wiring on the equilibrium diagram of iron-manganese-carbon alloys. A written discussion by Mr. Scott showed qualitative agree- ment, but some quantitative disagreement. Messrs. Marsh and Sisco discussed the paper at length, pointing out non- agreement of certain conclusions with the phase rule. Dr. Krivobok, although differing with the authors on some points, stated that in his opinion the information collected would be valuable in the practical use of these alloys.

Jan 1, 1932

By J. C. Todd

The volume of air needed to move the combustion wave through each acre-foot of the reservoir is a very important quantity for engineering economic analyses. A new method, which involves backflowing the injection well, has been developed for determining the air requirement .for the forward combustion thermal pilot in the Delaware-Childers field. The method depends on measurement of the total volume of air injected and measurement of the pore volume in the zone swept out by the combustion front. The basic premise of the method is that the pore volume of the swept zone contains air, while the formation around this zone contains flue gas, oil and water. The pore volume of the swept zone is determined by blowing down the pilot section of the formation through the injection well after the pilot is shut down. Oxygen balance is used to differentiate between air from the swept zone and flue gas from the surrounding formation. Data indicate that air'is produced from the swept zone by relatively efficient miscible displacement by the flue gas. The pore volume occupied by the air in the swept zone is determined by simple PVT relationships. The average temperature of the swept zone is calculated by heat balance from the total amount of heat generated during the pilot and losses to the surrounding formation. The new method was applied successfully at the conclusion of the pilot in the Delaware-Childers field; the air required for the reservoir conditions involved was calculated to be 19.2 MMscf/acre-ft of reservoir swept. INTRODUCTION One of the most important pieces of information to be found from a forward combustion pilot is the air requirement; that is, the volume of air needed to move the combustion wave through each acre-foot of the reservoir. Compression costs per barrel of oil recovered, which are a direct function of the air requirement, are a large portion of the expenses incurred in the thermal recovery process. Thus, the profitability of thermal recovery depends largely on the air requirement, which is a measure of the amount of fuel deposited and burned in the thermal recovery process. Several attempts have been made to correlate crude oil properties with fuel deposition and, hence, air requirement.l*2 Other attempts have been made by our laboratory to find the air requirement by material balance, gravity survey, pressure transient analysis,3 magnetic survey and the poten-tiometric model. Better methods are needed to predict more accurately the economics of fieldwide application of the process. Another method of finding the air requirement consists of operating a pilot thermal project for several years. This is followed by an extensive coring program to define the volume swept by the combustion wave. The air requirement is found from the total injected air divided by the volume of the swept region found from the coring operation. This method is costly; an adequate coring program usually costs several hundred thousand dollars. A thermal pilot was operated in a watered-out portion of the Delaware-Childers field, Bartlesville sand, from Nov., 1960, until May 3, 1965. One of the primary purposes of this pilot operation was to determine the air requirement for economic calculations which determine the advisability of expanding the project to the entire 128,000 acre-ft field. Barnes4 has described the result of this pilot operation,, including calculation of the air requirement from limited coring data. The value obtained, as calculated, was 15.8 MMscf/acre-ft. One purpose of this report is to describe a new method of finding the air requirement from a thermal pilot operation. A second purpose is to describe the application of this method to the Delaware-Childers thermal pilot. THEORY AND DESCRIPTION OF THE METHOD The combustion zone in the forward combustion process is propagated from injection w producing

Jan 1, 1970

By R. R. Harvey

Recent evidence has indicated that the films forming at crude oil-water interfaces are the result of naturally occurring su,rface-active components in the crude oil rather than oxidation products resulting from exposure of the oil to air. Since the presence of such films may strongly affect the displacement of oil from porous media, a knowledge of their composition and formatiorz is of fundamental importance. In this study, without the assumption of a specific mechanism, film formation is considered to involve the transfer of a weakly surface-active species in solution in the oil to the oil-water interface. The film gas law and the Gibbs adsorption equation may thus he applied to the system. The rigid films which form upon decrease of the oil-water interfacial area are considered a result of the very slow rate of re-solution of the film material into the oil. When the shrinkage of the interface is very rapid, the amount of film material leaving the interface is negligible, and the system may then be treated in the same manner as an insoluble film. The combination of these treatments leads to a new concept of the film factor in which it may he quantitatively related to the concentration of film-forming material at the interface. Suitable experiments can then yield the following information. 1. Original concentration of surface-active species in the oil. 2. The change of concentration with time. 3. Concentration of surface active species at the interface. 4. The change of this concentration with time. 5. Interfacial tension of the system at any time and its variation with time. 6. Equilibriunz concentrations for a given set of conditions. 7. Concentration requirements for solid film formation. 8. Molecular diameter of the adrorbed species. These calculations may be made solely from data taken from measurements on the original oil. While using the pendant drop method of interfacial tension measurement of crude oil-water systems, Bartell and Niederhauser' remarked on the thin, transparent, pliable, solid films or membranes which were often formed at the interface between crude oil and water. As a result of their observations of these films, Bar-tell and Niederhauser concluded: 1. The films are formed by material from the oil adsorbed at the interface rather than by a reaction at the interface. 2. The adsorption of the film-forming material is a rather slow process. 3. There are good indications that the process is reversible; i.e., the film constituents may re-dissolve into the oil. 4. The film will spontaneously spread over any new surface formed. 5. The process of adsorption at the interface is accompanied by a decrease in the interfacial tension of the system. Although they had proved that film formation was not due to a reaction at the interface, Bartell and Niederhauser were unable to demonstrate conclusively whether these film-forming constituents were present in the original reservoir oil or whether they were formed as oxidation products after exposure of the oil to air. Recent evidence seems to point to their presence in the original oil. Although the true nature of the film-forming constituents is still uncertain, these conditions would be fulfilled by the assumption of the presence of a slightly soluble surface-active component in the original oil. This component would migrate to a freshly formed interface because it would thereby lower the free energy of the system. The component at the surface constitutes an expanded monolayer which would become compressed, upon retraction of drop, due to the slow rate of re-solution of the film components into the bulk of the oil. It is possible, by involved extraction processes, to separate or at least concentrate this film-forming fraction. However, using the assumptions made above, the technique of monolayer film study may be applied to reveal much of the nature of the adsorbing material without resorting to an actual separation of the film-forming constituents.

By T. D. Mueller

Many investigators have used the response of the "dimensionless aquifer" to a unit pressure drop or a unit fluid-withdrawal volume to calculate the performance of an aquifer in supplying water influx to an oil reservoir. In the past, these response functions have been calculated with the aid of the Laplace transform. With the advent of ultra highspeed digital computers, it becomes practical to solve for the response functions with finite-difference techniques. The computer method also permits extension of the dimensionless-aquifer concept to include the nonhomogeneous aquifer wherein the permeability and other properties vary as a function of the space co-ordinates. This paper gives results of calculating the response functions for a series of nonhomogeneous aquifers. Response functions are presented for both linear and radial aquifers whose thickness, permeability-viscosity ratio and porosity-compressibility vary. These functions are new and should prove useful to the petroleum engineer in analyzing the behavior of nonbomogeneous aquifers. Results are presented in the form of charts that can be easily used by the field engineer. INTRODUCTION Aquifers which surround many oil and gas reservoirs have the ability to supply water influx to such reservoirs as oil and gas are withdrawn. This water influx, called natural water drive, provides one of the most effective driving mechanisms for the production of oil and gas. In producing a reservoir, therefore, it behooves one to make the maximum use of natural water drive. To achieve the maximum use, the reservoir engineer must be able to predict the performance of an aquifer under a variety of production schemes that may be proposed for the reservoir. Unfortunately, the physical properties which dictate aquifer behavior often are known only within limits. Seldom do wells penetrate the porous strata of the aquifer. Even when they do, quantitative information regarding porosity, permeability and water compressibility is seldom available. It is known, however, that the water efflux from most aquifer systems is governed by a single, relatively simple, linear, partial differential equation. Also, the general physical location of the aquifer boundaries often are known. A technique originall proposed by Hurst1 and van Everdingen and Hurst2 has been found useful in analyzing reservoirs in this situation. The idea was later expanded by van Everdingen, Timmerman and McMahan3 to include the mathematical technique of least-squares fitting. This latter method will be referred to as the VTM method. The basic assumptions of the VTM method include the following. 1. The location of the physical boundaries of the aquifer are known. 2. The flow conditions at these physical bound-daries are also known. 3. The aquifer is homogeneous; e.g., thickness, permeability, water compressibility and porosity are constant throughout. In the VTM method, a material balance is made on the fluids entering and leaving the reservoir. In the balance equations, the water-influx term is represented as the product of the water influx from an arbitrarily-selected, dimensionless aquifer system times an unknown conversion number. This balance can be formed as many times as there are data points in the history of the reservoir. Each time, the conversion number can be evaluated. If the reservoir engineer has picked the correct dimensionless aquifer to represent the real aquifer, the conversion number remains constant for all balances that have been made over the history period. If such a situation occurs, the reservoir engineer can then predict the performance of the reservoir for any type of production scheme by using the function associated with that particular dimensionless system and the derived conversion number. These functions will be referred to as the response function of the aquifer. If the aquifer is nonhomogeneous (e.g., if the porosity, permeability, thickness, porosity, or

By P. J. Root, J. E. Warren

An idealized model has been developed for the purpose of studying the characteristic behavior of a permeable medium which contains regions which contribute significantly to the pore volume of the system but contribute negligibly to the flow capacity; e.g., a naturally fractured or vugular reservoir. Unsteady-state flow in this model reservoir has been investigated analytically. The pressure build-up performance has been examined in some detail; and, a technique for analyzing the build-up data to evaluate the desired parameters has been suggested. The use of this approach in the interpretation of field data has been discussed. As a result of this study, the following general conclusions can be drawn: 1. Two parameters are sufficient to characterize the deviation of the behavior of a medium with "double porositym from that of a homogeneously porous medium. 2. These parameters can be evaluated by the proper analysis of pressure build-up data obtained from adequately designed tests. 3. Since the build-up curve associated with this type of porous system is similar to that obtained from a stratified reservoir, an unambiguous interpretation is not possible without additional information. 4. Differencing methods which utilize pressure data from the final stages of a build-up test should be used with extreme caution. INTRODUCTION In order to plan a sound exploitation program or a successful secondary-recovery project, sufficient reliable information concerning the nature of the reservoir-fluid system must be available. Since it is evident that an adequate description of the reservoir rock is necessary if this condition is to be fulfilled, the present investigation was undertaken for the purpose of improving the fluid-flow characterization, based on normally available data, of a particular porous medium. DISCUSSION OF THE PROBLEM For many years it was widely assumed that, for the purpose of making engineering studies, two param- eters were sufficient to describe the single-phase flow properties of a producing formation, i.e., the absolute permeability and the effective porosity. It later became evident that the concept of directional permeability was of more than academic interest; consequently, the degree of permeability anisotropy and the orientation of the principal axes of permeability were accepted as basic parameters governing reservoir performance. 1,2 More recently, 3-6 it was recognized that at least one additional parameter was required to depict the behavior of a porous system containing regions which contributed significantly to the pore volume but contributed negligibly to the flow capacity. Microscopically, these regions could be "dead-end" or "storage" pores or, macroscopi-cally, they could be discrete volumes of low-permeability matrix rock combined with natural fissures in a reservoir. It is obvious that some provision for the inclusion of all the indicated parameters, as well as their spatial variations, must be made if a truly useful, conceptual model of a reservoir is to be developed. A dichotomy of the internal voids of reservoir rocks has been suggested.7,8 These two classes of porosity can be described as follows: a. Primary porosity is intergranular and controlled by deposition and lithification. It is highly interconnected and usually can be correlated with permeability since it is largely dependent on the geometry, size distribution and spatial distribution of the grains. The void systems of sands, sandstones and oolitic limestones are typical of this type. b. Secondary porosity is foramenular and is controlled by fracturing, jointing and/or solution in circulating water although it may be modified by infilling as a result of precipitation. It is not highly interconnected and usually cannot be correlated with permeability. Solution channels or vugular voids developed during weathering or burial in sedimentary basins are indigenous to carbonate rocks such as limestones or dolomites. Joints or fissures which occur in massive, extensive formations composed of shale, siltstone, schist, limestone or dolomite are generally vertical, and they are ascribed to tensional failure during mechanical deformation (the permeability associated with this type of void system is often anisotropic). Shrinkage cracks are the result

By C. B. Manula, H. Gezik

In planning modem-day mining operations, management needs to pass from the area of subjective decision-making to an area of objective decision-makirlg. Planning procedures currently being practiced by many mine managers depend primarily on common sense and trial-and-error methods which oftentimes never reach optimum solutions. For this reason, an attempt is made to provide an understanding of linear programming to solve production planning problems. More specifically, a linear programming model is proposed to solve the production scheduling problem as it was found to exist in the crushed stone industry. Optimal production scheduling is of prime concern here, since the industry has to cope with seasonal demands for its products. The solution, as determined through the application of the model, provides management not only with an optimal production schedule but also with the following information regarding the improvement of existing facilities: (I) the location of bottlenecks which limit production and profit; (2) the directions in which the company i fixed equipment should be expanded or modified; and (3) the evaluation of unused resources. Future trends in stone production will quite likely parallel those in the construction industry. Continued record expenditures for structures such as dams, highways, and buildings are the reasons for this accelerated growth. Production forecasts for the next decade are predicted to be around one billion tons with an approximate 7% annual increase. The problem of increasing production from 570 million tons in 1966 to 1 billion tons by 1976 offers no small challenge. This situation is further compounded by other problems and economic factors. Population expansion, government regulation, labor agreement, and changes in technology wd cause managers and operators to be confronted by many more complexities than characterize present-day operations. Some of these. problems and economic factors are: (1) In some metropolitan and other urban areas, easily accessible sources of stone are almost depleted. Transportation costs will be a prime concern of the industry. (2) Population growth has forced residential expansion to a point where many quarry operators must conform to urban and suburban regulations. (3) Government regulation in regard to air and water pollution, noise, and reclamation as well as zoning developments necessitate that crushed stone producers keep abreast of changing conditions and requirements. (4) The crushed stone industry operates under pressure of a highly competitive situation. Every company's objective is to retain a favorable marketing position by exercising great attention to production and marketing costs. This is rather difficult, since the crushed stone industry is one segment of modern mining which has to cope with a seasonal demand for its products. Among the problems posed here, the one of exercising great attention to production and marketing costs is of current interest to management. Under seasonal demand conditions, this problem creates further difficulties for managers who need to plan and forecast. STATEMENT OF THE PROBLEM Various methods of Operations Research have been developed to handle a problem whose genesis is explained above. It is very seldom, however, that these quantitative means are used in practice by the mining industry. This paper describes the use of Operations Research methods to solve a production planning problem when demand is seasonal. The seasonal production planning problem is an important one because of the substantial costs associated with changing production, employment, and inventory levels to adjust to seasonal sales patterns. Most companies try to operate within reasonable levels of employment changes and hold inventories within storage capacities. In general, little or no attempts were made to develop minimum cosl schedules or to provide objective means to compare various production policies. When demand varies within a fixed time period, 11:-oduction requirements may be met by following one

Jan 1, 1970

By K. R. Grube, D. N. Williams

It is often desirable to perform fatigue studies at relatively high strains and at low strain rates. A low-cost fatigue machine has been constructed for this purpose which has proven quite versatile. This machine is based on the principle of repeated bending of a strip sample over a shaped mandrel. A photograph of a group of fatigue tests in progress is shown in Fig. 1. The test sample is held in place between two shaped mandrels having a flat at their base to grip the sample firmly. A cam-driven loading frame is used to bend the sample alternately over each mandrel. The sample slides freely in this frame and is held in place by a light spring to accommodate increases in sample length. The pivot point for the loading frame is selected so as to minimize movement at the loading point during operation. The number of cycles to failure is recorded by a rachet counter which is kept in operation by a series electrical connection through the sample and is operated by the drive cam. The maximum strain imposed at the sample surface on bending from one mandrel to the other is readily calculated from the relationship, where t is the sample thickness and r is the radius of curvature of the mandrels. The rate of straining can be controlled by control of the cam speed. The device as shown in Fig. 1 is set up to run six samples at ambient temperature. A much larger number of samples can be run at one time without difficulty. ALSO-, by slight realignment of the components the mandrel unit can be enclosed in a separate chamber permitting control of test temperature and environment. This permits a variety of fatigue and corrosion fatigue problems to be studied.

Jan 1, 1963

By A. Tremari, Paul I. Eimon

Photogrammetrists are studying with new interest the problems of mine mapping and mining engineers are beginning to see what photogrammetry can do for them. Administrators in a number of European and U. S. mines have tried photogram- metric methods and are finding that better maps and data, needed for mine development, can be produced with savings of time, men, and money. In addition to wide use in small scale mapping projects, photogrammetric methods are now used for producing large scale plans and maps in German coal and lignite mines, in some U. S. open pit mines, to inventory TVA coal stock piles, and to compute highway excavation volumes. In each case surveying and map compilation has been made more efficient and accurate by photogrammetry and at significant savings over ground methods.

Jan 5, 1959

By L. E. Snow, L. F. Pett

AT the Utah Copper Pit of Kennecott Copper Corp. a versatile mobile drill unit has been developed and tested. Through increased drilling speed and additional available drilling time, an improvement of 233 pct in drill performance has been realized. Operators using drill power can quickly and easily convert the unit from a vertical to a toe hole drill. Drilling is done with the machine in line with the unit or at right angles to it. Table I covers the 1950 drill record at the mine, showing the types of machines used and the footage obtained. [ ] Development of the new units was prompted by a desire for solution of the following problems: 1-The ever-expanding operations within the Utah Pit, requiring some 65 miles of transmission pipe lines radiating from a central compressed air plant, have now taxed this compressor plant beyond capacity. While 100 lb per sq in. pressure is maintained at compressors, transmission losses from innumerable small leaks result in low terminal pressure at the drills. Fig. 1 illustrates that while terminal pressure varies according to size of air hose and fittings used, the average drill is operating on air pressures within the 60 to 70-lb range. The compressor plant is operated primarily for air rock drills. All drilling is done on day shift, but it is necessary to run two of the three 3720 cu ft capacity compressors during night shift in order to prevent drastic loss of pressure through leaks. On day shift all three compressor units are operated at capacity, so that there is no reserve safeguard available for extensive repairs to any compressor. The calculated volume of compressed air required for operation of 25 drills is but 33 pet of three day-shift compressors. While compressed air is being used to a minor extent for purposes other than drilling, it is felt that satisfactory substitute facilities could be provided in the event that air lines were no longer available. 2-Drill performance has increased beyond the capacity of present 3 ½ -in. drifter machines. 3-The installation, maintenance, and moving of air lines in routine mining is a growing problem. The 2-in. level lines are placed outside electrification towers and must be moved to new location upon completion of each shovel cut. In addition to these moves it is often necessary to dismantle level lines so that excessive shovel spillage, or material covering track following a blast, can be pushed in the clear with bulldozers. Where level room is limited, it is often necessary to remove air lines in giving bulldozers room to prepare grades for wagon drills. In spite of precautions taken, many level lines become buried, twisted, and constricted, with excessive air loss resulting. Excessive back break in blasting often leaves several sections of air line suspended in mid-air. Occasionally air lines come in contact with defective electric transmission towers, so that holes are burned through pipe. 4-Rail-handling of drilling equipment such as wagon drills from one location to another requires considerable locomotive crane crew time. Any new unit developed should travel under its own power. 5-Present practice requires accessory material including hose, water pressure tanks, water barrels, drill steel, and bits to be transported by means of push cars when drill locations are changed on any level. 6-In order to supply numerous drill locations with material, many stock piles of new drill rods, drill bits, and other essentials must be left at strategic points, usually in the vicinity of powder magazines. This practice makes for poor housekeeping and contributes to the loss of supplies. Planning the Unit It was felt that a mobile drill unit which would rectify the foregoing problems should meet certain demands: 1-It must furnish compressed air to operate a 4-in. rock drill at a pressure of 90 to 100 lb.

Jan 1, 1952

By R. I. Jaff, H. R. Ogden, D. J. Maykuth

A phase diagram for alloys containing from 0 to 66.9 pct Mn was determined. Two compounds, tentatively labeled 6 and y, were found in this range. The 6 compound is located at about 66.9 pct Mn and melts congruently at 1330°C. The ? compound has a composition near 53 pct Mn and originates in a peritectic reaction at 1200°C between liquid and 6. ß and Y enter into a eutectic reaction at 1175°C. The ß phase field terminates in a very sluggish eutectoid reaction between a and ? at 550°C. MANGANESE is one of the important alloying addition elements to titanium. As a ß-stabiliz-ing addition for a-ß and ß alloys, it provides high strength with adequate ductility.' Two of the earliest commercial alloys contain manganese as a major alloying component.' The earliest published data on the constitution of Ti-Mn alloys was that of Wallbaum,~ who reported the existence of the compound TiMn2. The transformation range of commercial-purity Ti-Mn alloys was investigated by Craighead, Simmons, and Eastwood' who found limited a solubility and a lowering of the ß transus to about 790°C at 7 pct Mn. Preliminary work by the authors of this paper, using high-purity titanium, confirmed the ß-stabilizing action of manganese and showed the existence of several intermediate phases in the Ti-Mn system." More recently, McQuillan3 determined the ß transus temperatures for high-purity Ti-base alloys containing up through 4.4 pct Mn. These data are given in Fig. 1. The present investigation covered alloys made with a high-purity base. The constitution of titanium-rich alloys made with commercial titanium has been reported4," by Holladay, Kura, and Jackson. The alloy range covered in the present investigation was from 0 to 69.5 pct Mn. This alloy range extends slightly beyond the composition of the first congruent-melting compound encountered on proceeding from the titanium end of the system. A description of the materials and methods used in the determination of the diagram is given in the Appendix. The partial phase diagram determined for the Ti-Mn system is shown in Fig. 2. Details on equilibria in the titanium-rich alloys are given in Fig. 3. Liquid-Solid Relationships Observations on the cast structures of the arc-melted ingots showed that the terminal solid solution of manganese in ß titanium enters into a eutectic reaction with an intermetallic compound labeled ?. As will be shown later, this compound has a composition around 53 pct Mn. The eutectic reaction temperature was determined as 1175°C by thermal analysis which also showed that the ? phase originates in a peritectic reaction at 1200°C. Fig. 4 shows typical eutectic structures for alloy compositions on both sides of the eutectic composition which is located at 42.5 pct Mn. In alloys over the range of 45.4 through 69.5 pct Mn, a second intermetallic compound, labeled 6, was identifield as the primary phase. This phase consistently increased in amount as the manganese content approached 66.9 pct, and, as shown in Fig. 5, an alloy structure containing 66.9 pct Mn consisted essentially of the 6 compound. Thermal-analysis data indicate a melting point of about 1330°C for the 6 intermediate phase. At 67.0 pct Mn, small quantities of a new, higher manganese-content phase were observed in the form of Chinese-script eutectic particles. Comparison of Fig. 6a and b shows an increasing quantity of this phase as the composition was increased to 69.5 pct Mn. The formation of peritectic ? in arc-melted alloys containing 45.4 pct Mn and above appears to be almost entirely suppressed, as shown in Fig. 7a and b. This is because of the narrow freezing range available for its formation by peritectic reaction and because of the very high cooling rates obtained in

Jan 1, 1954

By P. L. Russell

The use of nuclear explosives for excavation has been demonstrated to be feasible and practical. Application of nuclear explosives for overburden removal from large ore deposits appears to offer economic advantages over present methods, but under the present pricing schedule, high-yield devices must be used to obtain an economic advantage. The use of nuclear explosives presents problems not inherent in the use of conventional explosives, and thus they can be used only in areas where large explosions and associated phenomena can be tolerated. Stripping of coal with nuclear explosives does not appear practical at this time, but stripping overburden from copper or iron ore deposits may be a potential use. Even here, however, the use of nuclear explosives would require isolation, favorable topography, favorable ground-water conditions, and a low population density. If these basic requirements can be met, the use of nuclear explosives for overburden removal would offer both economic and time advantages. The possibility of using nuclear explosives for peaceful purposes was a subject for speculation as early as 1945. The PLOWSHARE Program was formally established by the AEC in June 1957 for the purpose of developing and demonstrating peaceful applications for nuclear explosives. The technical direction of the program is the responsibility of the Lawrence Radiation Laboratory, Livermore, Calif. Mining and excavation were two fields that received early consideration as areas in which nuclear explosives might be used. Knowledge gained from underground weapons testing increased this possibility, and the development of the thermonuclear device which has a small fission-to-fission ratio, reduced the hazard of radiation, and spurred interest. Nuclear explosives appear to have the greatest potential in the following mining operations: 1.— Surface Mining a) Stripping of waste for open-pit excavation b) Breaking of ore in open-pit mining c) Quarrying d) Blasting for production of aggregate, riprap, etc. 2. — Underground Mining a) Block caving application b) Crushing of ore for in-situ leaching, etc. c) Preparation of underground waste disposal areas Of the potential applications, excavation is perhaps the most obvious and the best understood, and probably the most practical for use in the near future. Large quantities of rock and earth can be moved by proper emplacement of nuclear explosives, but economic and practical relationship must be determined between the known capabilities of nuclear explosives and the required excavating to remove overburden. REMOVING OVERBURDEN IN OPEN-PIT MINING Removing the overburden is one of the largest jobs in open-pit mining. In 1960 open-pit mines produced approximately 130 million tons of coal, 108 million tons of copper ore, and 135 million tons of iron ore. To obtain this much production, an estimated 3-billion tons of overburden were removed from the coal, 216 million tons from the copper ore, and 135 million tons from the iron ore. These figures do not include the initial stripping required before ore production. For example, the ASARCO Mission mine started stripping operations in August 1959 and by mid-November 1961 had removed 46.3 million tons of material including 1.2 million tons of ore.* Initial excavation of this type offers the most favorable conditions for utilizing the earth-moving ability of nuclear explosives. EXPLOSIVE CASTING FOR REMOVING OVERBURDEN The use of explosives to remove overburden is not a new idea. Conventional explosives have been used for this purpose for many years with varying degrees of success. Several small coal strip operators have used this idea to increase production. At these mines about one-third or more of the overburden is thrown by explosives across the pit and onto spoil piles. The additional costs of drilling more blast holes and more explosives are more than compensated for by a reduction in the time required to uncover the coal, and by an increase in coal production.

Jan 1, 1964

By B. H. Caudle, R. L. Slobod, E. R. Brownscombe

An earlier publication has discussed three methods lor obtaining relative permeability data on small core sample-: and the apparatus and technique for the capillary pressure displacement method. This paper describes the apparatus and technique for the solution gas and the dynamic displacement methods and presents a routine procedure for obtaining oil-gas and water-oil relative permeability data. Theoretical and experimental considerations are presented to show that the end effect commonly associated with the dynamic flow mechanism is extremely small where constant rates are employed in the flowing phase. An effect of flow rate on relative permeabilities obtained by the dynamic system is found only when gas is one of the flowing phases and this effect is ascribed to a form of channeling in the capillary system. The apparatus and procedure* used to obtain relative permeability data with three phases flowing are described and some preliminary results of the use of this method are shown. INTRODUCTION In a previous publication from this laboratory there appeared a brief discussion of the concepts behind three basic methods for obtaining relative permeability data.' These three methods were called the capillary pressure displacement method. the solution gas displacement method, and the dy. namic displacement method — the names being suggestive of the type of process used for obtaining the desired saturation prior to making the permeability measurements. In the same publication, the apparatus and technique for the capillary pressure displacement method were described and some typical results obtained by this method were presented. This paper will present: 1. The routine procedure used to obtain complete relative permeabilitv data (In small core samples with two phasec flowing; 2. The experimental techniques for the solution gas and dynamic displacement methods for obtaining relative permeability data; 3. The results of some studies on the mechanism of fluid flow through consolidated porous media; and, 4. The preliminary results on the determination of relative permeability for a system in which three phases are flowing. TECHNIQUE AND APPARATUS FOR THE DETERMINATION OF RELATIVE PERMEABILITY WITH TWO PHASES FLOWING In order to obtain relative permeability data on a small core sample which will describe the various phases of reservoir depletion. it is necessary that the methods used duplicate, as closely as possible, the various mechanisms involved in rescbrvoir depletion. It is important that. in any type of relative permedbility determination. the core be originally at virgin reservoir conditions with respect to the fluids within the pore *paces. (for example. oil used to displace water from core until connate water saturation estahlished). and that the subsequent saturation changes in the core be analagous to tile reservoir depletion mechanism for which the data are to he used. PROCEDURE OF DETERMINING RELATIVE PERMEABILITY DATA WITH TWO PHASES FLOWING A standardized procedure has been set up for obtaining relative permeability data and other information on small core samples. This procedure essentially consists of 11 steps as shown below: 1. Determination of tile capillary pressure curve.'! This information is used to help select samples for relative permeability determinations and to charactrrize. in general. the pore size distribution of the sample. 2. Determination of the specific permeabilities to air, oil. and water. These values are those on which the relative pern~eahility calculations are based. 3. Reduction of the core to connate water by an oil drive using the high speed centrifuge. 1. Determination of the critical gas saturation value and the associated relative permeability to oil by the solution gas drive method. 5. Determination of the relative permeabilities to oil and gab in the region where both phases are flowing by the capillary presqure method. 6. Reduction of the sample to residual oil in the centrifuge by an air drive. and the determination of the relative permeability to gas at this point.

Jan 1, 1951

By R. L. Slobod, B. H. Caudle, E. R. Brownscombe

An earlier publication has discussed three methods lor obtaining relative permeability data on small core sample-: and the apparatus and technique for the capillary pressure displacement method. This paper describes the apparatus and technique for the solution gas and the dynamic displacement methods and presents a routine procedure for obtaining oil-gas and water-oil relative permeability data. Theoretical and experimental considerations are presented to show that the end effect commonly associated with the dynamic flow mechanism is extremely small where constant rates are employed in the flowing phase. An effect of flow rate on relative permeabilities obtained by the dynamic system is found only when gas is one of the flowing phases and this effect is ascribed to a form of channeling in the capillary system. The apparatus and procedure* used to obtain relative permeability data with three phases flowing are described and some preliminary results of the use of this method are shown. INTRODUCTION In a previous publication from this laboratory there appeared a brief discussion of the concepts behind three basic methods for obtaining relative permeability data.' These three methods were called the capillary pressure displacement method. the solution gas displacement method, and the dy. namic displacement method — the names being suggestive of the type of process used for obtaining the desired saturation prior to making the permeability measurements. In the same publication, the apparatus and technique for the capillary pressure displacement method were described and some typical results obtained by this method were presented. This paper will present: 1. The routine procedure used to obtain complete relative permeabilitv data (In small core samples with two phasec flowing; 2. The experimental techniques for the solution gas and dynamic displacement methods for obtaining relative permeability data; 3. The results of some studies on the mechanism of fluid flow through consolidated porous media; and, 4. The preliminary results on the determination of relative permeability for a system in which three phases are flowing. TECHNIQUE AND APPARATUS FOR THE DETERMINATION OF RELATIVE PERMEABILITY WITH TWO PHASES FLOWING In order to obtain relative permeability data on a small core sample which will describe the various phases of reservoir depletion. it is necessary that the methods used duplicate, as closely as possible, the various mechanisms involved in rescbrvoir depletion. It is important that. in any type of relative permedbility determination. the core be originally at virgin reservoir conditions with respect to the fluids within the pore *paces. (for example. oil used to displace water from core until connate water saturation estahlished). and that the subsequent saturation changes in the core be analagous to tile reservoir depletion mechanism for which the data are to he used. PROCEDURE OF DETERMINING RELATIVE PERMEABILITY DATA WITH TWO PHASES FLOWING A standardized procedure has been set up for obtaining relative permeability data and other information on small core samples. This procedure essentially consists of 11 steps as shown below: 1. Determination of tile capillary pressure curve.'! This information is used to help select samples for relative permeability determinations and to charactrrize. in general. the pore size distribution of the sample. 2. Determination of the specific permeabilities to air, oil. and water. These values are those on which the relative pern~eahility calculations are based. 3. Reduction of the core to connate water by an oil drive using the high speed centrifuge. 1. Determination of the critical gas saturation value and the associated relative permeability to oil by the solution gas drive method. 5. Determination of the relative permeabilities to oil and gab in the region where both phases are flowing by the capillary presqure method. 6. Reduction of the sample to residual oil in the centrifuge by an air drive. and the determination of the relative permeability to gas at this point.

Jan 1, 1951

By A. L. Barnes

A number of reservoirs have been partially invaded by bottom water. Water flooding such reservoirs can be especially inefficient if the oil has a high viscosity because injected water will under-run the oil and emerge at producing wells without having displaced much oil. A possible means of improving water sweep efficiency would be to precede the water flood with a slug of water purposely thickened with a chemical additive. This possibility has been studied with a scaled laboratory flow model. The investigation was carried out on a model representing a 20-acre five-spot with one set of reservoir condition~. Displacements were performed with water, with viscous-water slugs of 10 and 25 per cent of the pore volume followed by water, and with all viscous water. Displacement tests were made at several rates of injection. For all cases, compared at the same producing water-oil ratio, an increase in rate resulted in an increase in volumetric sweep. The larger the quantity of viscous slug injected, the greater the crossflow of oil ahead of the displacing front and, thus, the lower the WOR during that period of a displacement. This investigation indicates that the injection of aqueous viscous slugs in this type of system would give some additional benefit over conventional flooding by (I) reducing the life of the flood, (2) reducing lifting costs and (3) increasing ultimate recovery. The benefits of a viscous-slug displacement would warrant its use if the viscous water could be created for a few cents per barrel. INTRODUCTION The most appropriate method for water flooding oil reservoirs which have been partially invaded by bottom water has been a problem of considerable interest. Such reservoirs, having good vertical permeability and unfavorable mobility ratios, are difficult to produce efficiently under normal waterflood procedures. Even though the injection wells have been plugged back above the oil-water contact and the water zone has been squeezed off, injection water will enter the formation and not only displace oil, but also much of it will displace the bottom water, thus creating a high producing water-oil ratio at the start of a flood (see Fig. 1). Since the rate of injection and the viscosity of the displacing fluid are the more easily controlled physical parameters of the reservoir, it is quite natural to study their effects on the volumetric sweep of the oil zone and on the producing water-oil ratio. Increasing the viscosity of the displacing fluid has two disadvantages—it reduces the maximum rate of injection into the reservoir, and it costs more than water. It was thought that the injection of a viscous-fluid slug, followed by water, would minimize these two disadvantages, increase the volumetric sweep of the oil zone and reduce the producing water-oil ratio. Water with an additive to increase viscosity would probably be the most effective. The primary purpose of this investigation was to determine the feasibility of injecting viscous-water slugs followed by water to improve or hasten oil recovery while reducing the producing water-oil ratios. The effect of injection rate upon recovery was also investigated. A laboratory model, scaled to a 20-acre five-spot prototype with one set of reservoir conditions, was constructed. Laboratory studies of displacements with (1) water, (2) viscous-water slugs of 10 and 25 per cent of the pore volume followed by water and (3) all viscous water were performed at several rates of injection. THEORY OF SAND MODEL SCALING There are two conventional means of determining scaling criteria. These are dimensional analysis and inspec-tional analysis. Determining scaling criteria by dimensional

By D. H. Shaffer, W. F. Harris, W. M. Hickam, M. H. Loeffler

Experiments have been performed on the quantitative addition to niobium of enriched isotopes 018 and 017 at the 0.1 - 40 micro-gram level and their subsequent recovery. A measured quantity of molecular oxygen of known isotopic concentration is added to niobium metal by oxidation. Recovery of the enriched isotopes as carbon monoxide is by the vacuum fusion technique. Quantitative determinations of the enriched isotopes are made in standard volumes at constant temperature using accurately calibrated micromanometers and the mass spectrometer as pressure measuring instruments. THE presence of low concentrations of nonmetallic impurities in metals can often adversely affect the physical properties of the metal. The increase in hardness and the embrittlement of refractory metals due to oxygen is well known. In metallurgical studies dealing with the diffusion rates or the effect of oxygen on the physical properties of refractory metals, it is often necessary to add small quantities of oxygen to the metal and later recover the total quantity present. It is desirable, therefore, to establish the accuracy with which microgram quantities of oxygen can be added to niobium and recovered by vacuum fusion. The successful addition of microgram quantities of oxygen to metals by the usual manometric techniques and the subsequent recovery by vacuum fusion is difficult because of the uncertainty in the accurate determination of the quantity of oxygen originally present in the metal and because of the chance of contamination by atmospheric oxygen. In order to minimize these uncertainties earlier workers have added quantities of O16 at levels much higher than the oxygen concentrations that are of interest.'-3 In order to eliminate the uncertainty associated with the O16 additions to metals at low microgram levels, experiments have been performed on the quantitative addition of oxygen highly enriched in O17 and O18 at the 0.1 to 40 pg level to niobium and the subsequent quantitative recovery of the isotopes by vacuum fusion. Since the natural abundance of O17 is 0.04 pct and of 0" is 0.2 pct this enriched oxygen provides a uniqueness from interference not achieved in earlier work.'-= A measured quantity of molecular oxygen of known isotopic concentration is diffused into the metal. Recovery of the isotopes in the form of carbon monoxide is by vacuum fusion. The total quantity of gas is determined in standard volumes at constant tempera- ture using accurately calibrated Consolidated Electrodynamics micromanometers and the mass spectrometer for pressure measurements. The molecular and isotopic composition is determined mass spectrometrically. APPARATUS A schematic of the oxygen addition apparatus is shown in Fig. 1. Take-offs are provided for the attachment of the isotope container and for sample bulbs which are used to transfer samples to the mass spectrometer. Metal valves are used throughout the system including the sample bulbs in order to achieve a vacuum of 10"6 mm Hg. Evacuation is accomplished with a 3-stage oil-diffusion pump backed by a mechanical pump. A liquid nitrogen trap is used to remove condensables and to prevent oil vapor from entering the system. A micromano-meter is used for pressure measurements. The furnace assembly is shown in Fig. 2. It consists of a quartz tube joined to the apparatus through a 40/W joint with Apiezon W low-pressure wax. The furnace cap, also a 40/W pyrex joint, is provided with a pyrex hook. The sample is suspended from this hook with a platinum wire. The total volume of the furnace section is 435 ml. All volumes were determined by expanding a known volume of gas at a known pressure into the evacuated system and re-measuring the pressure. Both the micromanometer used on the oxygen addition system and the micromanometer used on the mass spectrometer were compared to a precision

Jan 1, 1961

EVERY English-speaking mining, engineer or geologist knows that some terms used by his profession are not rigid but vary regionally; for example: what is called a vein by some, is called a lode by others and is known as a reef to their Australian colleagues. There are parallels in, the German language. Since, in addition, the meaning of some words may change considerably in 450 years-and other words may disappear completely-and not only the terminology but the concepts of a science are subject to drastic changes over such a long period of time, translating the Bergbüchlein posed some interesting problems. Old German texts and glossaries such as C. T. Delius' Anleitung zu der Bergbaukunst (1773), Minerophilus' Neues and Curieuses Bergwercks-Lexicon (1730), and H. Veith's Deutsches Bergwörterbuch (1871) proved useful sources of information when defini¬tions of obscure terms were needed. The task of translating was made even more challenging by the author's personality. As Ulrich Rülein von Kalbe was primarily a physician, his information must have been mostly secondhand. Since the nomenclature of the miners of Saxony, where he gathered his material on silver ores, undoubtedly varied from that of the German miners in Hungary, for instance, who probably supplied him with data on gold ores, it is not astonishing that he is not consistent in his use of some expressions. To give an example: there is every indication that Flöz and schwebender Gang (see footnote p. 21) are used interchangeably in spite of his occasional disapproval of such usage. It is obvious that he was an educated man with a questing and active mind and, although he apologizes-not wholly sincerely, one might suspect-for the simple

Jan 1, 1949

By C. A. Hope, H. B. Wishart

THE number and severity of surface imperfections on rolled slabs, assuming the reception of uniformly good quality heats from the open hearths, depend upon a number of conditions associated with heating and rolling of steel in the primary mills. While there are other elements that have an effect on surface quality, rather than make this paper too lengthy the discussion of mill processing variables will be limited to three factors in order to illustrate their effect on slab surface quality: 1—amount of reduction between ingot and slab, 2—slab finishing temperatures, and 3—influence of roll changes. Measurement of the percentage of surface removed by scarfing on the flat surfaces of the slabs was used for evaluating quality in this study. A study of this nature must be made on slabs that are inspected and conditioned under uniform conditions and standards. In order to be certain that steel of the best possible steelmaking quality was received at the rolling mills, a low carbon deep drawing grade of rimmed steel, made for sheet mill application and manufactured under carefully controlled open hearth practices, was selected. Use of this particular steel thereby reduced the steel quality factor as a possible source of variation. The measure of slab surface quality is the amount of surface removed by scarfing during yard conditioning and is expressed as percentage of surface removal. This percentage was estimated by experienced personnel to uniform standards and it should be noted that these percentage figures are representative only for the grade selected and under the rigid inspection standards to which the slabs were subjected. Surface removal is a matter of concern because the imperfections, if undetected, often are the cause of poor surface quality in the finished product and their removal, by conditioning, add to the total plant costs. The data was collected at various times over a period of six months and, with normal weekly fluctuation in the level of quality, it is to be expected that for any period of sampling there will be some variation in the plotted results. The type of defect that is responsible for most slab conditioning at Gary Steel Works is a light angular surface break. This defect is usually interconnected to form large defective areas and occurs mainly on the bottom half of the slab on both sides. This type of defect is illustrated in Fig. 1, showing a bottom portion of a slab; while a close-up of an area of the same slab where the surface breaks were found is given in Fig. 2. The large dark areas are heat patterns, results of hot stacking and cooling. Independent of these light breaks, but sometimes associated with them, are larger and deeper isolated breaks. However, most of the surface removal occurs from conditioning the large areas of small breaks. There are also occasional scabs of varying degrees of severity but these are relatively infrequent. The slabs are generally free of rolled-in scale. Ingot to Slab Reduction vs Quality Some ten years ago at Gary Steel Works, the minimum slab ingot thickness was 30 in. Subsequent operating and other quality features indicated the desirability of using an ingot of reduced thickness with the result that a series of molds that would produce a 22 in. thick ingot with various widths was adopted as standard. A minimum number of the thicker mold sets are still used. From the standpoint of quality difficulties from pipe and segregation, the smaller ingots are an improvement. From a quality surface viewpoint, the slab product from the thin molds requires approximately twice the surface removal as the slab product from the thick molds. This is shown in Fig. 3 where the percentage of surface removal is plotted against slab product rolled from

Jan 1, 1956

By H. F. Smiley, Fred Sehmann

The production of the North Central Texas area comes entirely from the Pennsylvanian section with the exception of one pool in Cooke County and one in Young County where oil has been, produced from the weathered surfaces of Pre-Pennsylvanian peaks overlapped by oil-bearing strata of Pennsylvanian age. In the southern part of the area the Strawn and Bend groups furnish the production, the Strawn sands being the predominating horizons at depths from 1500 to 3000 feet. In the northern part of the area including North Young, Archer, Wichita, Wilbarger, and Clay counties, the Cisco group has produced consistently for nearly 30 years from sands ranging in depth from 700 to 2500 ft. To our knowledge there are 13 separate producing sands in t,he Cisco group ranging from 200 to 1800 ft. in Wichita County. During the past three years, deeper drilling has opened three new producing horizons. A Canyon sand in Central Archer County has produced from 400 to 800 bbl. per well at a depth of 2200 ft.; and in the same pool, owned jointly by the Deep Oil Development Co. and Lindsay Drilling Co., a Strawn sand was found at 3600 ft. which produced 75 bbl. per day. In Southern Wichita County the Bend group has been found productive. A very oolitic sandy lime series from 3675 to 3942 ft. has produced in three wells drilled to date. During the past year the district has been producing under an extreme proration which accounts for the small production figures for 1932, as well as the few drilling activities at the end of the year. Table 1 presents the available drilling and production data compiled by the North Texas Oil and Gas Association.

Jan 1, 1933