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By Lester C. Uren

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

Jan 1, 1925

By C. A. Hartnagel, D. H. Newland

The market for Pennsylvania grade showed a drop both in demand and in prices, which reacted unfavorably on New York oil production, all of which comes under that classification. The output for the year in New York amounted to 5,045,200 bbl. The production in 1937 was 5,478,000 bbl., the largest in any year for the last half century or more. Falling prices, of course, affected new drilling. They declined from $2.20 a barrel, which was posted at the start, to $1.68 in the final months of 1938. With this came a reduction in the amount of oil that would be accepted by the refineries operating in the New York fields. Conditions therefore have combined to halt, at least temporarily, the growth of oil production in the state, which had experienced a steady gain for the last 15 years or more, the yield having risen from less than 1,000,000 bbl. to the round total of 5,500,000 bbl. in 1937. Practically all the oil now obtained is from old, developed fields. No new pools have been found in the last quarter of a century or more. The larger share comes from flooding the sands. Although there are many wells that still produce without the aid of the water drive, they are small and for the most part are pumped periodically. Of late, new drilling has been restricted mainly to that required to maintain existing flood projects. Because of the high initial cost and time required to put a flood into production, the depressed condition of the market has been a serious handicap financially, and, further, has been an unfavorable influence on the planning of operations to secure the maximum recovery of the oil. Unless market conditions improve, it is certain that the effects will be shown in the yield for some time to come. Gas Developments Drilling was active in the southwestern area, chiefly in Allegany and Steuben Counties, and some notable wells were brought in that tapped the Oriskany sandstone. Altogether 42 holes were put down in the two counties, of which 31 were listed as producers and 11 were dry. The new wells gave an initial daily flow of 239,000 M cu. ft. At the close of

Jan 1, 1939

By C. A. Hartnagel, D. H. Newland

The market for Pennsylvania grade showed a drop both in demand and in prices, which reacted unfavorably on New York oil production, all of which comes under that classification. The output for the year in New York amounted to 5,045,200 bbl. The production in 1937 was 5,478,000 bbl., the largest in any year for the last half century or more. Falling prices, of course, affected new drilling. They declined from $2.20 a barrel, which was posted at the start, to $1.68 in the final months of 1938. With this came a reduction in the amount of oil that would be accepted by the refineries operating in the New York fields. Conditions therefore have combined to halt, at least temporarily, the growth of oil production in the state, which had experienced a steady gain for the last 15 years or more, the yield having risen from less than 1,000,000 bbl. to the round total of 5,500,000 bbl. in 1937. Practically all the oil now obtained is from old, developed fields. No new pools have been found in the last quarter of a century or more. The larger share comes from flooding the sands. Although there are many wells that still produce without the aid of the water drive, they are small and for the most part are pumped periodically. Of late, new drilling has been restricted mainly to that required to maintain existing flood projects. Because of the high initial cost and time required to put a flood into production, the depressed condition of the market has been a serious handicap financially, and, further, has been an unfavorable influence on the planning of operations to secure the maximum recovery of the oil. Unless market conditions improve, it is certain that the effects will be shown in the yield for some time to come. Gas Developments Drilling was active in the southwestern area, chiefly in Allegany and Steuben Counties, and some notable wells were brought in that tapped the Oriskany sandstone. Altogether 42 holes were put down in the two counties, of which 31 were listed as producers and 11 were dry. The new wells gave an initial daily flow of 239,000 M cu. ft. At the close of

Jan 1, 1939

By G. E. Keller

In connection with the work of Committee D5, Coal and Coke, of the American Society for Testing and Materials in developing new standards and improving old standards, series of tests were made to check the variance of sample preparation and analysis of American coals. Table I in the "Tentative Method of Preparing Coal Samples for Analysis - 02013-62T" is rather complicated, and the tests were designed to develop data for the simplification of this table. An allowance of 20% of the total variance of sampling and analysis for the sample preparation and analysis steps was used. Also, instead of coals being grouped into ash ranges, they were grouped as washed and raw (unwashed) coals. As a result of these tests, a simplified Table I for Tentative Standard 02013 has been proposed. A standard test for laboratories to check their variance of sample preparation and analysis has been developed. Committee D5 on Coal and Coke of the American Society for Testing and Materials has been making a study of all standards applying to coal for the purpose of improving and bringing them up to date and for breaking some of the existing standards covering a number of tests into single standards. As an illustration, sample preparation is now partly covered in ASTM Designation D492-48, Sampling Coals Classified According to Ash Content, and partly in ASTM Designation D271-58, Laboratory Sampling and Analysis of Coal and Coke. The latter contains, in addition to parts of sample preparation, methods for determining Moisture, Ash, Volatile Matter, etc. Although revision of sampling methods and sample preparation methods are now assigned separately, it is possible that they may end up as one standard. One of the first new Tentative Standards developed as the result of these studies was ASTM Designation D2013, Tentative Method of Preparing Coal Samples for Analysis. Although this method is quite an im- provement over that in the old standards and gives very specific instructions, Table I (attached) is quite complicated and rather hard to understand. In order to take advantage of reduced quantities or weights, it is necessary to know the ash content within rather narrow limits before sample preparation and no distinction is made as to whether the coal is cleaned or uncleaned. No limits of accuracy are assigned to the sample preparation and analysis. The total over-all accuracy of sampling, preparation and ash determination as given in D492-48 has been specified for commercial sampling procedure as follows: "This procedure is intended for an accuracy such that if a large number of samples were taken from a single lot of coal, the test results in 95 out of 100 cases would fall within ? 10 per cent of the average ash content of the sample." Although Appendix 11, Method for Determining the Over-All Variance of Reduction and Analysis in the Tentative Methods for Mechanical Sampling of Coal, ASTM Designation D2234-63T, does give a method for determing the over-all accuracy of preparation and analysis expressed as variance and also the F test, it does not permit the determination of the variance at the various stages of reduction or of the ash determination. It was decided in 1961 to ask a number of laboratories to run a series of tests for the purpose of determining the variance at various stages of reduction and analysis with the view of simplifying Table I of the Tentative Standard D2013-62-T. This paper is a record of this series of tests with recommendations which resulted from the tests. At the same time and preceding these tests the International Organization for Standardization under Committee TC/27 WG 7 was studying the same problem. Tomlinson1 of England and Dr. paul2 of West Germany had made studies giving quite a bit of information. Also Schwerd and coryel13 published some information which was the main basis for the Mechanical Division provision in ASTM Tentative Standard D2013-62T, Table I. In checking with the various laboratories which offered to cooperate in these tests, none was found which used mechanical division through the entire preparation procedure. It was then decided to use riffles at all stages with the thought that if riffles gave satisfactory variances, approved mechanical

Jan 1, 1965

By C. Williams, D. V. Carter

During 1943 five oil fields and two gas-condensate fields were discovered in the East and East Central Texas district. The New Hope field, discovered by Tide Water-Seaboard in Franklin County, is the most important oil discovery since the Hawkins field in 1940. At the close of the year two oil sands were producing and two additional oil sands were being tested. The gas-condensate fields of Appleby in Nacog-doches County and the Stewards Mill field in Freestone County had only one producing well each. The Carthage field was extended 3 miles north and 4 miles west. Another well that was testing at the year end indicated a probable eastward extension of several miles. The Quitman field, in Wood County, was the most active from the standpoint of drilling operations. Approximately 48 wells were complcted during the year. The second and third most active fields were Hawkins field, Wood County, and Kildare field, Cass County, respectively. Wartime restrictions of material, together with manpower shortage and Federal spacing regulations, reduced the number of oil and gas-well completions from 265 in I942 to 171 in 1943. This represents a drop of 35 percent, or approximately 1/3, enough to replace the 531 producing wells abandoned in the district during the year. No changes were made in the price of crude oil in the district in 1943. The district produced 177,652,940 bbl. of condensate and oil during 1943. This represents an increase of approximately 11 per cent compared with the previous year. The East Texas field, which is the largest and most important field in the district, had an annual production of 128,568,647 bbl. of oil, which is approximately 6.5 per cent more than the previous year, and represents 72 per cent of the district's production of condensate and oil for the year. The district had an estimated basic daily allowable of approximately 509,000 bbl. of oil on Dec. 31, 1943. The entire district produced approximately 30 pcr cent of the state's production for the year 1943. The Hawkins field, Wood County, was operated 271 days during the year and with an average daily production of approximately 52,488 bbl. for the year. This field, which is the second largest in the district, produced 14,224,164 bbl, of oil during the year. Changes in annual production in certain fields in the district can be attributed to their ability to produce at higher rates, the demand, and transportation facilities in the war effort. The East Texas field showed an over-all decrease in reservoir pressure of 8.30 lb. during the year. Indications were that through the first quarter of 1944 the return of salt water to the reservoir was having a beneficial effect. It is hoped that, as more and more water is returned to the reser-

Jan 1, 1944

By D. V. Carter, C. Williams

During 1943 five oil fields and two gas-condensate fields were discovered in the East and East Central Texas district. The New Hope field, discovered by Tide Water-Seaboard in Franklin County, is the most important oil discovery since the Hawkins field in 1940. At the close of the year two oil sands were producing and two additional oil sands were being tested. The gas-condensate fields of Appleby in Nacog-doches County and the Stewards Mill field in Freestone County had only one producing well each. The Carthage field was extended 3 miles north and 4 miles west. Another well that was testing at the year end indicated a probable eastward extension of several miles. The Quitman field, in Wood County, was the most active from the standpoint of drilling operations. Approximately 48 wells were complcted during the year. The second and third most active fields were Hawkins field, Wood County, and Kildare field, Cass County, respectively. Wartime restrictions of material, together with manpower shortage and Federal spacing regulations, reduced the number of oil and gas-well completions from 265 in I942 to 171 in 1943. This represents a drop of 35 percent, or approximately 1/3, enough to replace the 531 producing wells abandoned in the district during the year. No changes were made in the price of crude oil in the district in 1943. The district produced 177,652,940 bbl. of condensate and oil during 1943. This represents an increase of approximately 11 per cent compared with the previous year. The East Texas field, which is the largest and most important field in the district, had an annual production of 128,568,647 bbl. of oil, which is approximately 6.5 per cent more than the previous year, and represents 72 per cent of the district's production of condensate and oil for the year. The district had an estimated basic daily allowable of approximately 509,000 bbl. of oil on Dec. 31, 1943. The entire district produced approximately 30 pcr cent of the state's production for the year 1943. The Hawkins field, Wood County, was operated 271 days during the year and with an average daily production of approximately 52,488 bbl. for the year. This field, which is the second largest in the district, produced 14,224,164 bbl, of oil during the year. Changes in annual production in certain fields in the district can be attributed to their ability to produce at higher rates, the demand, and transportation facilities in the war effort. The East Texas field showed an over-all decrease in reservoir pressure of 8.30 lb. during the year. Indications were that through the first quarter of 1944 the return of salt water to the reservoir was having a beneficial effect. It is hoped that, as more and more water is returned to the reser-

Jan 1, 1944

By L. H. Duschak

Electrolytic zinc produced from sulfate solution and with pure lead anodes is always contaminated with a small and varying percentage of lead. The purpose of this investigation is to determine the characteristics of several lead alloys and their influence on the products of electrolysis and power consumption. The study of alloyed anodes has been a matter of interest for some years. Tainton, Taylor and Ehrlinger prepared a highly interesting paper' on this subject a year ago, in which the effects of silver-lead and some ternary alloys of lead-silver-tin were described, and the presentation of any paper on insoluble anodes will owe much to the inspirational results achieved by Dr. Colin G. Fink and Li Chi Pan in their work on insoluble anodes for the electrolysis of brine,2 and to other published papers by Dr. Fink and his coworkers embracing the development of the copper-silicon-manganese anode for the production of electrolytic copper and the general subject of anode development. The present paper describes a study of various combinations of 10 metals. The general plan of the work provides for the fabrication of the alloyed anode, its adequate conditioning by preparatory electrolytic operation, the production of cathode zinc and its analysis, the determination of the anode polarization, and other features. A list of the anodes tested, showing composition and polarization at various current densities together with the lead assay of the cathode zinc, is shown in Table 1. Determination of Anode Polarization In the determination of anode polarization under operating conditions it is essential that the anode area used be restricted to the side facing the cathode, in order that these measurements may be referred to a definite current per unit of area. It becomes necessary, therefore, to insulate the inactive face of the anode, to prevent the leakage of lines of force

Jan 1, 1930

By F. J. Haller

IN 1943, we found, in the new Mather operation, a very unusual and disappointing condition in the footwall rock where all of our main haulageways were to be located. With the exception of a few hundred feet out of the thousands then planned and since driven, all of the openings require support. In general, the ground is not particularly heavy, at least by our standards, but it must be supported and the back carefully covered. Also, our operations require rather wide plat openings (16 to 18 ft) and rather flat curves at the turn-outs, all of which adds to the problem. When this completely unforeseen condition was discovered, ordinary timbering was the only answer, because of the impossibility of obtaining adequate steel supplies in time due to war shortages. Then by the time steel supplies were obtained and a practice developed, we found ourselves with between four and five miles of main haulage drifts and plat openings of a permanent nature, all of which were supported by hardwood timber, some of which had already rotted to an unsafe degree. Also, our drifting program was adding some two miles per year to the above figure. F. J. HALLER, Member AIME, is Superintendent, Mather Mine, Cleveland-Cliffs Iron Co., Ishpeming, Mich. AIME Columbus Meeting, September 1949. TP 2840 A. Discussion (2 copies) may be sent to Transactions AIME before May 31, 1950. Manuscript received Aug. 22, 1949. Revision received Jan. 17, 1950. To give all of the details of our experiments, studies, and experiences would fill a large book, but we were satisfied that our organization had done an excellent job, starting from scratch. You can appreciate our surprise when we discovered that we had added very little to an existing record. Attention was called to a footnote in a copy of "Carnegie Pocket Companion" year 1923. The note read: "Full information as to uses of H-Beams is given in pamphlet entitled 'Steel Mine Timbers.' " A search of our Engineering Library brought to light a pamphlet printed in 1911 showing extensive use of steel for this purpose. Except for welding in place of riveting, we have added very little to the designs in that book. We have, however, developed an experience which proves, at least to our own satisfaction, that steel mine supports pay off under the proper conditions. We are now convinced, in spite of the relatively high initial cost of materials, that steel sets, because of comparatively low installation cost, are actually cheaper than either treated or untreated wood sets, if they are properly designed and adapted. Several Sections in Use: Convenience guided our first experiments in steel sets, since for a number of years, we had used the 4-in. WF, 10 lb per ft section in 10-ft lengths as safety forepoles along with wood forepoles. This section replaced the 40-lb rail which had formerly been used for the purpose. Having the 4-in. WF sections on hand, it was natural that our first experiments in steel sets involved their use. Later, the rolling of the 10-lb section was discontinued in favor of the much stronger 13-lb section, which is now standard for both legs and caps in areas of no particular weight, but which, none the less, require permanent support. Our experiments involved the use of the 10- and 13-lb sections as legs and 6- and 8-in. I beams, 16 and 23 lb per ft, respectively, as caps. Experience soon indicated that, if the ground were heavy enough, and the opening wide enough to require a cap stronger than 13-lb, the 8-in, 23-lb should be used, eliminating the 6-in. I beam. We now know that the 8-in. WF section of the same weight, which we propose to use in the future, is considerably stronger for the amount of money involved. Comparative Strengths: Tables I to IV giving strengths of several species of timbers as compared with the structural sections that we now use have been prepared in accordance with accepted practice. Experience indicates that failure due to compression perpendicular to the grain of the wood does not destroy the effectiveness of a wood set frequently enough to be a practical factor. Therefore, no table of these values is included.

Jan 1, 1951

By F. J. Haller

IN 1943, we found, in the new Mather operation, a very unusual and disappointing condition in the footwall rock where all of our main haulageways were to be located. With the exception of a few hundred feet out of the thousands then planned and since driven, all of the openings require support. In general, the ground is not particularly heavy, at least by our standards, but it must be supported and the back carefully covered. Also, our operations require rather wide plat openings (16 to 18 ft) and rather flat curves at the turn-outs, all of which adds to the problem. When this completely unforeseen condition was discovered, ordinary timbering was the only answer, because of the impossibility of obtaining adequate steel supplies in time due to war shortages. Then by the time steel supplies were obtained and a practice developed, we found ourselves with between four and five miles of main haulage drifts and plat openings of a permanent nature, all of which were supported by hardwood timber, some of which had already rotted to an unsafe degree. Also, our drifting program was adding some two miles per year to the above figure. F. J. HALLER, Member AIME, is Superintendent, Mather Mine, Cleveland-Cliffs Iron Co., Ishpeming, Mich. AIME Columbus Meeting, September 1949. TP 2840 A. Discussion (2 copies) may be sent to Transactions AIME before May 31, 1950. Manuscript received Aug. 22, 1949. Revision received Jan. 17, 1950. To give all of the details of our experiments, studies, and experiences would fill a large book, but we were satisfied that our organization had done an excellent job, starting from scratch. You can appreciate our surprise when we discovered that we had added very little to an existing record. Attention was called to a footnote in a copy of "Carnegie Pocket Companion" year 1923. The note read: "Full information as to uses of H-Beams is given in pamphlet entitled 'Steel Mine Timbers.' " A search of our Engineering Library brought to light a pamphlet printed in 1911 showing extensive use of steel for this purpose. Except for welding in place of riveting, we have added very little to the designs in that book. We have, however, developed an experience which proves, at least to our own satisfaction, that steel mine supports pay off under the proper conditions. We are now convinced, in spite of the relatively high initial cost of materials, that steel sets, because of comparatively low installation cost, are actually cheaper than either treated or untreated wood sets, if they are properly designed and adapted. Several Sections in Use: Convenience guided our first experiments in steel sets, since for a number of years, we had used the 4-in. WF, 10 lb per ft section in 10-ft lengths as safety forepoles along with wood forepoles. This section replaced the 40-lb rail which had formerly been used for the purpose. Having the 4-in. WF sections on hand, it was natural that our first experiments in steel sets involved their use. Later, the rolling of the 10-lb section was discontinued in favor of the much stronger 13-lb section, which is now standard for both legs and caps in areas of no particular weight, but which, none the less, require permanent support. Our experiments involved the use of the 10- and 13-lb sections as legs and 6- and 8-in. I beams, 16 and 23 lb per ft, respectively, as caps. Experience soon indicated that, if the ground were heavy enough, and the opening wide enough to require a cap stronger than 13-lb, the 8-in, 23-lb should be used, eliminating the 6-in. I beam. We now know that the 8-in. WF section of the same weight, which we propose to use in the future, is considerably stronger for the amount of money involved. Comparative Strengths: Tables I to IV giving strengths of several species of timbers as compared with the structural sections that we now use have been prepared in accordance with accepted practice. Experience indicates that failure due to compression perpendicular to the grain of the wood does not destroy the effectiveness of a wood set frequently enough to be a practical factor. Therefore, no table of these values is included.

Jan 1, 1951

By C. D. Locker

COMMON salt is mentioned in the most ancient writings as an impor-tant article of diet. It is fairly certain that it was used by men and animals long before the dawn of civilization. Its presence in natural springs has often been the determining factor in colonization; wars have been fought for possession of salt deposits; trade routes have been estab-lished expressly for the purpose of traffic in salt. Naturally this led men into adventures and discoveries that altered history and advanced civilization. In the early days the uses for salt were few and the methods of manu-facture were crude and the purity low when compared to salt of the pres-ent day. Then the salt came largely from springs, shallow wells or the ocean, while today deep wells must be drilled to the natural brines or beds of rock -salt and spacious shafts sunk so that the ancient deposits may be made to yield their supply of stored mineral.

Jan 1, 1936

By Morris Cohen

It has been known for several years that in certain age-hardenable alloys precipitation of finely divided particles occurs simultaneously with the changes in physical properties; while, in other alloys, these changes take place prior to, or without any, precipitation. The silver-copper alloys are generally considered to be the classical example of the first group, and the aluminum-copper alloys (duralumin) are typical of the second group. The two types of aging are explained by the precipilation theory and the knot theory respectively.‡ It is well recognized now that these theories do not conflict with each other; the one used for a given aging system depends upon which way the alloy in question happens to age-harden. However, previous work on the aluminum-copper al1oys1,2 has shown that if the aging temperature is raised sufficiently the hardening will be accompanied by actual precipitation. In fact, it is quite probable that all of the so-called knot-hardening alloys will harden by precipitation at elevated temperatures. Therefore, a combination of the knot and precipitation theories is necessary to give a complete picture of the agehardening of these alloys, and indicates that knot formation and precipitation are not independent processes. To test the generality of this concept, it is necessary to show that the alloys that commonly harden by precipitation will harden prior to precipitation if the aging temperature is sufficiently lowered. For this reason, it would be well to carefully re-examine the aging characteristics of the silver-copper alloys at aging temperatures somewhat below those used by previous investigators. If hardening can be detected prior to precipitation in these alloys, it will lend great weight to the idea that knot forma-

Jan 1, 1937

By John Birkinbine

An unusually large number of crystals of magnetite obtained in the exploitation of a deposit of magnetic iron-ore of remarkable purity, encouraged the preparation of this paper, and its presentation at this time, that the matter might go on record in the Transactions. To make this record more complete, a preliminary statement is offered concerning the district and locality in which the ore is found. To the northeastern portion of the State of New York the United States is indebted for a large percentage of the iron-ore which has assisted in developing the resources and industries of the nation. As early as 1804, iron-ore was mined between Lake Champlain and the Adirondack mountains, and this district has since been an important and continuous contributor to our iron-ore supply. The production of the Lake Champlain district for the last, eleven years is as follows: Years. Gross tons. 1879,...........420,341 1880,...........531,000 1881,...........637,000 1882,...........675,000 1883,...........500,000 1884,...........504,894 1885,...........379,077 1886,...........588,752 1887,...........768,852 1888,...........789,419 1889,...........750,230 Approximate total,.....6,644,565

Jan 1, 1890

By A. R. Denison

Several productive areas in the Mid-Con-tinent are broadly and briefly examined with respect to the present depth of drilling on productive structures, and the thickness of sediments remaining untested. Evidence is offered to show that a vertical mile to two miles of untested but prospective formation remain within reach of the drill. In no case would a well deeper than 15,000 ft. be required, and in most cases to no greater depth than 10,000 ft. Recent outstanding success of deeper prospecting in West Texas demonstrates the merits of deeper drilling on known structure. Introduction New fields discoverd during I942 equaled or exceeded the number in any preceding year. The total amount of oil found by these discoveries was less than in any previous year, for which accurate records are available. This means that the pools now being discovered are much smaller than in past years. This is to be expected, since the prospects available during 1942 were largely those overlooked in the earlier years and therefore represent a second or third order (in quality) of structural feature. This failure to find pools of good size and quality raises grave doubt as to the security of our future oil supply. With military needs rising almost daily, and the period of heaviest con- sumption in our war effort still in the future, there is even a growing doubt as to our ability to supply the amount needed for our ultimate victory. This does not mean that our reserves are inadequate, but rather that our "capacity to produce" may be inadequate. Lacking large fields with flush production, our capacity to produce is rapidly approaching our current needs. ,Since the industry is unable to find the large new fields necessary to keep a safe margin of "capacity to produce," other means are needed. It seems obvious that one of these should be deeper prospecting on the large, proven, productive structural features now known. The exploratory wildcat is drilled primarily in search of a trap and the reason for failure to find oil and gas in nine out of ten cases is due to the absence of a suitable trap under the drill site. Therefore, deeper drilling on a known structural feature that is productive largely eliminates the greatest hazard in wildcat drilling. While by no means all the oil known today is found in structural traps—in fact, some have estimated that less than half is so located— the fact remains that structural traps are far more commonly the oil fields that have multiple horizons of production superimposed one over the other. Outstanding examples are the Eldorado field in Kansas, the Tonkawa and Cushing fields in Oklahoma, the Louden and Salem pools of Illinois, and the richest and most prolific of all structural traps, the Long Beach, Ven-tura and other similar fields of California.

Jan 1, 1944

By A. R. Denison

Several productive areas in the Mid-Con-tinent are broadly and briefly examined with respect to the present depth of drilling on productive structures, and the thickness of sediments remaining untested. Evidence is offered to show that a vertical mile to two miles of untested but prospective formation remain within reach of the drill. In no case would a well deeper than 15,000 ft. be required, and in most cases to no greater depth than 10,000 ft. Recent outstanding success of deeper prospecting in West Texas demonstrates the merits of deeper drilling on known structure. Introduction New fields discoverd during I942 equaled or exceeded the number in any preceding year. The total amount of oil found by these discoveries was less than in any previous year, for which accurate records are available. This means that the pools now being discovered are much smaller than in past years. This is to be expected, since the prospects available during 1942 were largely those overlooked in the earlier years and therefore represent a second or third order (in quality) of structural feature. This failure to find pools of good size and quality raises grave doubt as to the security of our future oil supply. With military needs rising almost daily, and the period of heaviest con- sumption in our war effort still in the future, there is even a growing doubt as to our ability to supply the amount needed for our ultimate victory. This does not mean that our reserves are inadequate, but rather that our "capacity to produce" may be inadequate. Lacking large fields with flush production, our capacity to produce is rapidly approaching our current needs. ,Since the industry is unable to find the large new fields necessary to keep a safe margin of "capacity to produce," other means are needed. It seems obvious that one of these should be deeper prospecting on the large, proven, productive structural features now known. The exploratory wildcat is drilled primarily in search of a trap and the reason for failure to find oil and gas in nine out of ten cases is due to the absence of a suitable trap under the drill site. Therefore, deeper drilling on a known structural feature that is productive largely eliminates the greatest hazard in wildcat drilling. While by no means all the oil known today is found in structural traps—in fact, some have estimated that less than half is so located— the fact remains that structural traps are far more commonly the oil fields that have multiple horizons of production superimposed one over the other. Outstanding examples are the Eldorado field in Kansas, the Tonkawa and Cushing fields in Oklahoma, the Louden and Salem pools of Illinois, and the richest and most prolific of all structural traps, the Long Beach, Ven-tura and other similar fields of California.

Jan 1, 1944

By George Rice

WHEN miners in the interior coal fields of the United States began the practice of blasting the coal without undercutting, or what is known as "shooting off the solid," many explosions resulted, some of them of great extent and 'violence, and attended with large loss of life. One of the means adopted for preventing this large loss of life, though not preventive of explosions, was to employ shot firers to discharge the shots when all the other employees had gone out of the mine at the end of the day's shift. This system still prevails in most of the Central and Southwestern mines. Following the disaster at Winter Quarters mine, Utah, May 1, 1900, in which 200 lives were lost, a system of firing shots electrically from outside and when the men were out of the mine was adopted at the mines of the Utah Fuel Co.1 This system has also been used in France in certain mines that are subject to instantaneous outbursts of carbonic acid gas. These outbursts generally occurred at shot-firing time, on account of the blasts releasing the gas held in crevices under high pressure. The system was also adopted at a number of other mines in Utah, at the Cokedale mine, Colorado, at the Dawson mines, New Mexico, and in some mines of the Tennessee Coal, Iron & Railroad Co. in the Birmingham Ala. district; and more recently in certain mines in Iowa and Kansas. At first there was considerable trouble from misfires, and in a few instances from premature firing, while men were in the mine, through the shot-firing lines becoming crossed with power lines. Fortunately, however, no loss of life resulted from such premature firing within the knowledge of the writers, and latterly this danger has been reduced to a minimum by certain measures of precaution. The proportion of misfires, or failures of individual shots to fire, has also been reduced to a very small

Jan 10, 1914

By J. A. Lund, A. M. Lawson

THE structures of quenched eutectoid and hypereu-tectoid Fe-Cu alloys have been examined by X-ray diffraction and by optical and electron microscopy. The relevant portion of the Fe-Cu phase diagram is given in Fig. 1. Several values have been reported for the solubility of copper in a Fe at the eutectoid temperature, including 1.4 wt pct by orton' and 2.13 wt pct by Wreidt and Darken.2 Alloys containing 4.8 and 7.5 wt pct Cu have been prepared from two batches of Ferrovac E iron (0.005C and 0.013C) and electrolytic tough pitch copper (99.90 Cu). Specimens of dimensions 0.8 by 0.8 by 0.1 in. were cut from hot-rolled material, austenitized, and quenched into brine at 25°C. Similar specimens were also cooled in the furnace, after a short soaking treatment at 1100°C, at a rate estimated to be 10°C per min in the temperature range of 900" to 500°C. X-ray diffractometry was performed on quenched and on furnace-cooled bulk specimens using iron radiation. Only a bcc phase could be detected in all samples. Lattice parameters were calculated from measurements on four lines, made up of two resolved high-angle doublets. Comparisons were made against a silicon standard. Results are shown in Table I. Based on X-ray diffraction studies of a series of alloys of lower copper concentrations, orton' estimated that the tattice constant of a Fe at 25°C increases 0.0014A per wt pct Cu in solution. Extrapolating Norton's data, it may be concluded that all copper was retained in solution in the brine-quenched 4.8 pct Cu alloy, and that approximately 5 pct Cu was also held in solution on quenching the 7.5 pct Cu alloy. Typical microstructures of brine-quenched specimens, as observed by optical microscopy, are shown in Figs. 2 and 3. Precipitation of the E phase (copper-rich) occurred along the y grain boundaries on quenching the 7.5 pct Cu alloy, rendering them readily detectable in the microstructure, Fig. 3. The original boundaries in the 4.8 pct Cu specimens were gener- ally not discernible, however. This indicates that the z phase which was seen in the higher-copper alloy was probably of proeutectoid origin. Thin foils for transmission electron microscopy were obtained from bulk specimens by spark machining to 0.006 in. thickness, followed by electrolytic polishing. Typical transmission electron micrographs

Jan 1, 1967

By M. E. Lombardi

THE Coalinga oil field is located on the west side of the San Joaquin Valley, California. The structure is in general a monocline, the edges of the oil horizon resting on the foot hills and dipping gently toward the east. One prominent anticline occurs plunging southeast. The earlier drilling was done in the foot hills comparatively near the outcrop and the wells were shallow. The sands were followed eastward and, in the case of the anticline, along the plunge, the wells becoming deeper and deeper until the depth of 4,000 ft. was reached and passed. There is nothing to show that the oil will not be found in quantity at still greater depth. In fact, some of the best producers have tapped the sand at close to 4,000 ft. The recovery of oil still farther to the east, and therefore at greater depth, seems to be mainly a question of drilling. In this territory the formations drilled through are chiefly sands and shales; they will not "stand up" in an open drilling hole; the casing has to be carried close to the bit, and it is always difficult to keep the casing free for any considerable distance. Ability to carry casing of comparatively large diameter without conductor pipes for distances of 2,000 or 3,000 ft. or over is desirable in such territory chiefly for two reasons. It makes it possible to enter the oil sand with a pipe of ample diameter; it eliminates one or more expensive strings of casing which act only as conductors for the water string, and furthermore, in territory where waters are encountered which corrode steel rapidly, it makes possible the construction of a rust- and alkali-resisting water string. It is always desirable to shut off top waters, which may lie within 100 ft. or less of the oil sand, with 10-in. pipe. Where the depth is so great that a practical weight of 10-in. pipe will not withstand the probable collapsing pressures, 8 ¼ in. at least is desirable. About the limit of rotary drilling to date in California seems to be the setting of the 10-in. string at 3,200 ft., although the rapid advance in rotary work during the past year seems to indicate that this depth may soon be increased. It is my purpose now, however, to treat only of cable-tool drilling.

Jan 2, 1915

By R. A. Vandermeer, Paul Gordon

On the basis of a unified concept, theoretical erPressions for grain boundary migration in recrys-tallization are derzved for impurity-controlled and impurity-independent migration. The expression in the former case is analogous to that Previously derived by Lucke and Detert, and in the latter is shown to be equivalent to that usually obtained on the basis of absolute reaction rate theory. The equations are tested with quantitative experimental data for boundary migration obtained for the recrystallization of poly crystalline zone-refined alumimnz and for binary "alloys" of this aluminum with 0.00021, 0.00043, 0.0017, 0.0034, 0.0068, 0.0124, and 0.0256 at. pct Cu, respectively. All the essential characteristics of the e@erimentally determined boundary migration rates check both qualitatively ard quantitatively with the predictions of the theoretical equations. THE rates of transformations are customarily analyzed phenomenologically in terms of the two component rates—N, the rate of nucleation and, G, the rate of growth of the nuclei. The scientific aim of both theory and experiment is to describe the fundamental atomic phemmena involved in these two component processes with the hope that parameters calculated from theoretical equations will check those found experimentally. In solid state transformations, the theoretical and experimental problems are both generally of almost prohibitive complexity, for in addition to changes in composition and in such properties as density which may accompany transformations in amorphous, nonrigid materials, transformations in crystalline substances also involve structural changes, crystal reorientations, and the development of stresses. In studying such transformations it thus becomes; highly desirable, if not essential, to focus on a transformation and a set of conditions which minimize the number of active variables. This principle has been applied with considerable success by Cohen and his associates' in their evaluation of nucleation theories using the martensite transformation as the basis of study. A similar possibility exists for the evaluation of growth theories by the use of recrystallization after cold-deforming. If an unalloyed metal is employed as the subject of investigation, the recrystallization transformation involves basically only a change in strain-conditions and orientations. In spite of this possible simplilfication, however, until recently little quantitative success has attended attempts to correlate recrystal1ization parameters measured experimentally with those calculated theoretically. It seems highly probable that this lack of success may be attributed, both in the experimental and theoretical treatments, to one or more of the following factors: a) conditions have usually been studied under which apparently* both nucleation and growth are active;

Jan 1, 1962

By Charles R. Holmes

MORE than 70 igneous pipes and dikes are known to occur in Cambrian sediments throughout an approximately circular area of about 75 sq miles in southwestern Ste. Genevieve County and southeastern St. Francois County, Mo., across the southern portion of the Farmington anticline, which is outlined in fig. 1. From evidence obtained from fossil fragments taken from some of the in-trusive~, and from the similarity in composition of the more basic intrusives to those of known age in surrounding states, these pipes and dikes are believed to be at least post-Devonian and probably Cretaceous in age. As first postulated by Rust,' these intrusives are believed to represent explosion tubes, or diatremes, punched through great thicknesses of solid rock by gaseous pressure. The particular intrusive studied is located about 1 mile north of the small town of Avon at an elevation of 880 ft in the EVz SEy4 NEY4 of see. 2, T. 35N, R. 7E. Outcrop is through the Bonneterre dolomite in two separated exposures. The larger outcrop extends east and west for about 50 ft along a tributary in a small ravine (fig. 2). The smaller exposure occurs as a few scattered patches over an area 20 ft square about 100 ft to the north. The area between the exposures is covered, but scattered patches of the Bonneterre dolomite outcrop throughout the area surrounding the diatreme. Where exposed, contact relations show the surrounding dolomite to be shattered and metamorphosed to a fine-grained rock for a distance of 15 to 20 ft from the intrusive. The igneous rock occurs as a dark greenish-gray porphyry near the center of the diatreme and as a fine-grained, greenish-gray material containing lapilli and metamorphosed fragments of dolomite near the contact with the country rock. The most abundant original mineral of the porphyritic rock is olivine now largely serpentinized as the result of extensive hydrothermal alteration at time of emplacement. The most common constituent of the fine-grained rock, which occurs near the border of the intrusive, is calcite. Mica is a common constituent of both types of rock, occurring as tufts or flakes. Magnetite makes up about 2 pct of the diatreme and occurs as small irregular grains or streaks of tiny grains. Singewald and Milton' have termed the rock of this body an "augite-free alnoite." Susceptibility measurements of pulverized specimens were made from selected samples taken from both the diatreme and the surrounding country rock. The susceptibility of the Bonneterre dolomite was found to be less than 40xlO-6 cgs (centimeter-gram-second) units and that of the metamorphosed contact dolomite less than 200x10-6 cgs. Measurements of individual samples of the igneous rock showed a wide variation in susceptibility between limits of 1000x10-6 cgs to 8000x10-6 cgs, with the maximum difference occuring in samples taken only a few feet apart. The maximum value was exhibited by a highly weathered sample taken from the northern outcrop, while minimum susceptibility was determined from a partially weathered sample taken only a few feet away. These extremes are believed to represent small local concentrations of stringers and grains of magnetite crystals in the igneous rock. A detailed magnetic survey of the horizontal and vertical components of the earth's magnetic field was made over the diatreme area. Stations were occupied at 20-ft intervals as shown by the grid on fig. 2. When greater detail was desired, intervening stations were also occupied. The field instruments were supplied by the Department of Geophysics, St. Louis University. The magnetometers are the Schmidt balance type constructed by the Ruska Instrument Co. These instruments are temperature compensated and have a standard sensitivity of 10 gamma. Calibration of the instruments

Jan 1, 1951

By Charles R. Holmes

MORE than 70 igneous pipes and dikes are known to occur in Cambrian sediments throughout an approximately circular area of about 75 sq miles in southwestern Ste. Genevieve County and southeastern St. Francois County, Mo., across the southern portion of the Farmington anticline, which is outlined in fig. 1. From evidence obtained from fossil fragments taken from some of the in-trusive~, and from the similarity in composition of the more basic intrusives to those of known age in surrounding states, these pipes and dikes are believed to be at least post-Devonian and probably Cretaceous in age. As first postulated by Rust,' these intrusives are believed to represent explosion tubes, or diatremes, punched through great thicknesses of solid rock by gaseous pressure. The particular intrusive studied is located about 1 mile north of the small town of Avon at an elevation of 880 ft in the EVz SEy4 NEY4 of see. 2, T. 35N, R. 7E. Outcrop is through the Bonneterre dolomite in two separated exposures. The larger outcrop extends east and west for about 50 ft along a tributary in a small ravine (fig. 2). The smaller exposure occurs as a few scattered patches over an area 20 ft square about 100 ft to the north. The area between the exposures is covered, but scattered patches of the Bonneterre dolomite outcrop throughout the area surrounding the diatreme. Where exposed, contact relations show the surrounding dolomite to be shattered and metamorphosed to a fine-grained rock for a distance of 15 to 20 ft from the intrusive. The igneous rock occurs as a dark greenish-gray porphyry near the center of the diatreme and as a fine-grained, greenish-gray material containing lapilli and metamorphosed fragments of dolomite near the contact with the country rock. The most abundant original mineral of the porphyritic rock is olivine now largely serpentinized as the result of extensive hydrothermal alteration at time of emplacement. The most common constituent of the fine-grained rock, which occurs near the border of the intrusive, is calcite. Mica is a common constituent of both types of rock, occurring as tufts or flakes. Magnetite makes up about 2 pct of the diatreme and occurs as small irregular grains or streaks of tiny grains. Singewald and Milton' have termed the rock of this body an "augite-free alnoite." Susceptibility measurements of pulverized specimens were made from selected samples taken from both the diatreme and the surrounding country rock. The susceptibility of the Bonneterre dolomite was found to be less than 40xlO-6 cgs (centimeter-gram-second) units and that of the metamorphosed contact dolomite less than 200x10-6 cgs. Measurements of individual samples of the igneous rock showed a wide variation in susceptibility between limits of 1000x10-6 cgs to 8000x10-6 cgs, with the maximum difference occuring in samples taken only a few feet apart. The maximum value was exhibited by a highly weathered sample taken from the northern outcrop, while minimum susceptibility was determined from a partially weathered sample taken only a few feet away. These extremes are believed to represent small local concentrations of stringers and grains of magnetite crystals in the igneous rock. A detailed magnetic survey of the horizontal and vertical components of the earth's magnetic field was made over the diatreme area. Stations were occupied at 20-ft intervals as shown by the grid on fig. 2. When greater detail was desired, intervening stations were also occupied. The field instruments were supplied by the Department of Geophysics, St. Louis University. The magnetometers are the Schmidt balance type constructed by the Ruska Instrument Co. These instruments are temperature compensated and have a standard sensitivity of 10 gamma. Calibration of the instruments

Jan 1, 1951