Search Documents

By W. P. Huleatt, Jr. Traver, Jr. Hazen

"Vanadium and uranium occur widely distributed throughout western Colorado and eastern Utah, and a few deposits have been found in northeastern Arizona and northwestern. New Mexico. The area in which it occurs includes approximately 10,000 square miles and is generally referred to as the vanadium region of Colorado and Utah.The majority of the deposits consist of replacement bodies and impregnations of rare minerals in the lower Morrison formation of Jurassic age. The ore bodies are flat, with irregular margins, and most of them conform to the stratification.The ""rim rock"" topography of the region includes many steep-walled canyons and plateaus, which afford an abundance of outcrops that have been responsible for most of the discoveries of mineralized areas. Delimitation of ore bodies within the areas is accomplished most effectively by core drilling from the surface.The deposits were discovered in 1899 and from 1911 to 1923 wore worked extensively for radioactive uranium ores, principally carnotite.The discovery and marketing of the richer and more cheaply mined pitch-blende ores of the Belgian Congo left the Colorado-Utah deposits without economic importance as sources of radium and uranium, and the region became inactive in 1923. After a period of comparative inactivity, the rising demand of the alloy-steel industry for vanadium renewed interest in the deposits, which were known to contain that metal. By 1938, vanadium production in the area had achieved respectable proportions, and new impetus was given to it by the United States’ entry into World War II in December 1941. In 1942, new treatment plants for vanadium ores were completed in Monticello, Utah, and Durango, Colo. In order to meet the requirements of these and other plants in the region, it became necessary to open new vanadium mines and prepare old onus for production.In an effort to stimulate mining, the Metals Reserve Company initiated a stock-piling program and appointed the united states Vanadium Corporation, to act as its purchasing agent.The extra production was expected to come largely from small, independent operators whose limited funds did not permit them to maintain development and exploratory programs. Study of conditions made it apparent that extensive exploration would be necessary to sustain production, and accordingly the Bureau of Mines initiated an exploratory drilling project on a cooperative basis with the Geological Survey. The principal objects of the work were to enlarge the known ore reserves of the area and, if possible, discover new ones. The results have been gratifying in both respects."

Sep 1, 1946

"INTRODUCTION While investigating prevention of sabotage and maintenance of production of essential war minerals, engineers of the Bureau of Mines visited more than 1,400 metal and nonmetallic mines, quarries, and open pits in all parts of the United States.The need for, uniform safety practices is indicated by the fact that during 1938-1940, inclusive, the Western Safety Conference, under the sponsorship of the California Department of Industrial Relations, undertook the prepara¬tion of a set of standard safety regulations for the 15 participating political subdivisions. The membership of these political subdivisions is comprised of representation from Alaska, Arizona, British Columbia, California, Colorado, Hawaii, Idaho, Lower California, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming, For the guidance of its own engineers; the Bureau of Nines found it necessary to prepare a set of safety practices that could be used uniformly throughout the United States. These safety practices were compiled from State mining regulations, mining company safety rules, and the experience of Bureau of Mines engineers for more than 3 decades, and represent the best safety practices of the Nation's' mineral industry.The purpose of this publication is to make safety practices available for the non-coal branches of the mineral industry, with the hope that they may assist in reducing accident occurrence. The Bureau will welcome questions and suggestions regarding these practices in order that changes may be made as necessary.Where the adoption of any practice would not materially increase the safety of employees or would work undue hardship on the operator, the Bureau does not recommend such adoption."

Sep 1, 1946

By R. G. Knickerbocker, T. E. Evans, J. L. Morning, D. R. Torgeson, F. W. Wessel

"INTRODUCTION Pilot-plant studies on processes for converting low-grade domestic manganese ore to high-grade oxide or sulfide products by pyrometailurgical process was initiated at the Boulder City, Nev., Experiment Station in 1942. These investigations were given impetus by the possibility of a national shortage of ferro-grade manganese oxide for war needs.The manganese ore employed-in most of the pilot-plant smelting tests was from the manganosiderite-nodule deposits at Chamberlain, S. Dak. This deposit although low-grade, is extensive and represents, the largest reserve of manganese in continental United States. 6/ The Bureau of Mines has recently developed a Carryall mining-conical rolls treatment method that shows promise of making possible economic removal and subsequent beneficiation of the nodule-bearing shales. 7/ Smelting tests were made also on Artillery Peak, Ariz., mill concentrates in the productions of unrefined manganese matte for the steel The pilot-plant smelting program was based upon the fundamental fact that manganese, like copper, will sulfidize and become miscible with FeS. The matte this formed represents the initial smelting step in the pyrometallurgical treatment of the beneficiated ore. The concentrated nodules containing about. 18 percent manganese were smelted with varying amounts of pyrites and appropriate fluxes to produce Mns-FeS mattes containing 16 to 50 percent manganese. When the manganese and iron was completely sulfidized, the mattes contained 16 to 23 percent manganese. Reducing the pyrite resulted, of course, in the selective sulfidization of manganese and the production of a matte containing a correspondingly higher ratio of MnS to FeS. Complete sulfidization smelting produced slags of lower manganese content and hence resulted in higher manganese recoveries in the matte."

Sep 1, 1946

By Charles E. McCarthy, MORTON T. PAWEL, E. A. GEE, FRANK S. RIORDAN

Large tonnages of the magnesium silicate mineral , olivine, are known to exist in the mountains of western North Carolina and in the Puget Sound region of Washington. The North Carolina deposits alone are reputed to contain at least 230 million tons of ore averaging 45 to 49 percent of magnesium oxide In both areas the mineral is readily accessible and can be mined by the simplest methods ; one of the largest of the Washington deposits is located at tidewater .

Sep 1, 1946

By R. H. Storch

"A preliminary examination of the Bi-Metallic molybdenum prospect was made in October 1944, as a result of which it was recommended that a trench exploration project be undertaken on the property. This report presents the information obtained from project work done during June 1945.In its program of exploration of mineral deposits, the Bureau of Lanes has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to the national security and. economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.With respect to this report, special acknowledgment is due S. H. Lorain, chief, Albany Division, Mining Branch, for aid in preparing the report.The property is situated in the NW1/4, sec. 26, T. 39 N., R. 29 E. about 21 miles northeast of Tonasket. Tonasket (population 643), the nearest town, is a way point on a branch line of the Great Northern Railway. The prospect is reached by a good gravel road through Havillah to Vincent's ranch, about 3 miles northeast of Havillah. From the ranch, an abandoned dirt road extends to the portal of the Moly alit, about 1 mile distant. The mine road could be kept open without difficulty if properly graded and surfaced."

Aug 1, 1946

By Andrew Brown

"In recent years operators of brown-ore mines have shown increasing interest in .the reclamation of ore heretofore lost in tailing ponds. In January and February.1945 the author made a preliminary survey of the ponds in the Russellville district, Franklin County, Ala. The Russellville district (fig. 1) was chosen for the preliminary work because it contains many large ponds in a comparatively restricted area. All important properties in the district were visited with Charles R. Wilson of Russellville, who has been familiar with the Franklin County brown-ore industry since 1890; with Edmund Craddock and W. S. Blackburn, managers of the two washers now operated near Russellville by Shook & Fletcher Supply Co., and with S. A. Britton, manager of the Sloss-Sheffield Steel & Iron Co. washer. The larger ponds were measured roughly and tonnages estimated. and samples taken from different areas were analyzed and beneficiated at the Southern Experiment Station of the Bureau of Mines; Tuscaloosa, Ala.The ponds explored were the Sloss No.1 (Ensley); the Sloss No. 8, and the Sloss No. 4-5, which are among the largest in the district and so located, within an area of .three square miles (see fig. 2), that ore from all of them could be-treated,one centrally located washer.Actual work was begun on May 9. Between that date and June 30, when field work was completed, 246 holes in ponds were drilled and sampled, and 15 additional holes were put down primarily to test the drill .in different types of ground with a view to its possible utilization in other types of prospecting. Samples from all holes were analyzed for iron content; samples from 13 holes were sized and analyses made for each size fraction, and six large samples have been composited for beneficiation tests.Brown iron ore has been mined in the Russellville district since 1815, when the first blast furnace in Alabama was built in NW1/4 sec. 10, T. 7 S., R. 12 W., about 3 miles southwest of Russellville (19).-J The furnace was abandoned before the Civil War, and mining continued on a small scale until 1888, when Enoch Ensley began to mine the ridge between Russellville and Pain Creek. His first washer, Ensley No. 1, was about 300 feet south of the junction of the present Tharptown road with the Waco spur of the Southern Railway."

Aug 1, 1946

By E. O. Binyon

"Corundum and andalusite were discovered in August 1944 on what is now known as the Blue Metal group of claims. The property, comprising five unpatented lode claims, is situated 20 Miles northwest of Yerington in the Buckskin Mining District, Douglas County, Nevada, An engineer of the. Bureau of nines examined the property on November 1, 1944, and recommended a small: amount of drifting and crosscutting to determine more definitely the extent and character of the ore deposit. The work that had been done by the owners was for sampling purposes only and was confined to a few small pits on the outcrop, and no effort had been made. to delimit the ore zone. Samples taken from the best surface showings were sent to the experimental station in Salt Lake City for beneficiation tests. The results of the preliminary test work appeared favorable, and upon the strength of them and the recommendations made by the Bureau, 2.5 miles of access road was approved and completed early in 1945. Exploration was started on June 24 and completed September 26, 1945.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mines resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.This paper is one of many reporting on various aspects of the Bureau of Mines program initiated in August 1939 by passage of the Strategic Minerals act, the scope of which was. greatly expanded by subsequent legislation.Some of these papers were published as war minerals reports, others as bulletins, technical papers, reports of investigations, and information circulars of the Bureau of Mines or• in, technical journals.The Bureau's program at first included separate investigations by the Mining and metallurgical Divisions, but these were consolidated under Assistant Director R. S. Dean beginning July 1, 1942. Mining and metallurgical investigations carried on in three regional organizations more closely integrated thereafter by a staff of specialists, who reviewed findings made in the field and in Bureau Laboratories, considered proposals for additional work, revised reports for publication, and served as advisors to the assistant director."

Aug 1, 1946

By Staff

"INTRODUCTION Sheet mica is one of the most important minerals in modern industry. It is used in many kinds of electrical devices, and up to the present time no satisfactory substitute for it has been developed. It is necessary for the successful operation of airplanes, ships, motor vehicles radios, and radar equipment. Early in World y r II, the Array and Navy, foreseeing the need for conserving the stock of sheet mica on hand and realizing that imports from India and Brazil were falling off, had strategic mica placed on the critical war-materials list.Examination and exploration by the Bureau of nines indicated that there probably are large undeveloped deposits of mica in Alabama, some of which are near the surface and others at greater depth. The quality of most of this mica is high.During World War I, Alabama mica producers added materially to domestic production, but after 1920 virtually all of the mines closed end miners scattered. During World War II, when imports from India, Madagascar,Brazil,,other foreign sources were reduced, sometime was required for Alabama to act into production. Operators began to produce small quantities in 1942.The Colonial Mica Corporation was created by the Government during 1942 to buy Mica for the Metals Reserve Company, end later Colonial was made sole buying accent for strategic mica. About this time the Bureau of Mines estab¬lished the graphite field laboratory at Ashland, Ala. Samples of mica wore submitted for examination, and advice was requested by property owners and mine operators. This continued during 1943, when as many as 400 visitors a month called at the Bureau's Ashland field laboratory."

Aug 1, 1946

By William Seymour

"INTRODUCTION Byproduct-coke manufacture is one of our country's most essential in¬dustries; its importance was strikingly accentuated by the demands of World War II. This paper reviews recent progress in various phases of byproduct-coke operations for the production of metallurgical coke particularly that used as blast-furnace fuel.In the early days of the by-product-coke industry in the United States high-grade bituminous coking coals, both high-volatile or gas coal and low-volatile Pocahontas coal, were plentiful, and the selection and mixing of coals for coke-oven use were minor problems.The demands of World War I for the production of iron, steel, and coke aroused and stimulated new interest in the investigation of the reserves, characteristics, and properties of our coking coals. During that war the increased demand for coke reached a critical stage, and the shortage of high-grade coking coals necessitated the use of cols of inferior quality and of different coking characteristics than those previously used.The period of prosperity following World War I brought much progress and development in the by-product-coke industry. Methods of testing coal and coke were improved. The search for satisfactory coking coals was continued, and construction and design of byproduct ovens were improved."

Jun 1, 1946

By B. F. Naylor, C. H. Shomate, F. S. Boericke

"Ilmenite is the most important titanium-bearing constituent of titaniferous iron ores. Such ores, of which the United States has abundant reserves, are of interest because they constitute an important potential source of both iron and titanium that may be tapped in times of stress, and which eventually may be utilized in the normal course of events.As the iron and titanium constituents of titaniferous iron ores are not completely separable from each other by ore-dressing methods, any process for metal recovery will, of necessity, involve reduction of the iron in ilmenite. Consequently, knowledge of the thermodynamic properties of ilmenite should supplement information already available concerning those ores. With this in view, the Pacific Experiment Station of the Bureau of Mines undertook to evaluate thermodynamic properties; the data obtained are the subject of this report.Three types of experimental work were involved. First, low-temperature specific heats of ilmenite were measured in the temperature range 500 to 29S° K. These data serve to evaluate the entropy, a quantity necessary for a reliable evaluation and correlation of other thermodynamic properties. Second, high-temperature heat-content measurements were made in the temperature range 298° to 1,743° K. The data serve to bridge the gap between room temperature and elevated reduction-process temperatures. Finally, hydrogen-reduction equilibria were measured in the temperature range 1,220° to1,375° K. These data-give a direct measure of the free energy of reduction of ilmonite at these temperatures and, in conjunction with results of the other two types of measurements, serve to obtain the heat of formation of ilmenite, a quantity not readily determinable by direct calorimetric means.The data are correlated to form a composite, self-consistent portrayal of the thermodynamic properties of ilmenite, which may be used in evaluating the efficacy of any reducing agent of known thermodynamic properties. Selective-reduction of iron in ilmenite by hydrogen, carbon monoxide, and carbon are considered in this report."

May 1, 1946

By H. S. Auvil, L. D. Schmidt, H. G. Graham

"Several studies on the bulk density of coals prepared for byproduct-oven use were undertaken during the war by the Bureau of lanes in cooperation with the Office of the Solid Fuels Administrator and with the advice of the Coke Production Committee. The primary purpose of these studies was either to produce more uniform coke or to increase the throughput of existing facilities or both; the goal was increased Production of steel for war. As these studies were made, detailed reports were sent to the individual companies with whom the Bureau cooperated; also two reports,5/6/on the general subject of bulk-density control were published. In the course of the work, data were gathered that now prove of value in judging the merit of carious methods of testing bulk density and the limits of application of each method in byproduct-oven operations.Since the cessation of hostilities, the .Bureau section (Coke Production Survey Section) that conducted this work has been liquidated, but it was felt advisable to prepare a report on the accumulated experience so that it would be in a form available for the use of the industry and also as a base for any further research on the control of fluctuating bulk densities in coke ovens.It is hoped that the data and experiences recorded herein will be of material assistance to the many who have had difficulty in obtaining reproducible results in bulk-density testing. Since the data were gathered in the course of extending aid to individual plants in minimizing the deleterious effects of fluctuations in bulk density of oven charges on the quality and quantity of coke produced, certain desirable phases of an over-all investigation were not covered. However, on certain of these phases qualitative indications are available and the policy followed herein is that suggested by the American Society for Testing Materials Manual on Presentation of Data7/ that lacking quantitative information, relevant material should be included even though it ""may be qualitative in character, some may even be vague."""

May 1, 1946

By William Seymour, L. D. Schmidt, J. W. Myers, W. T. Reid

"This investigation was conducted by the Bureau of Mines as part of a program of the Solid Fuels Administration to encourage the utilization of anthracite fines, the objective being to determine the practicability of using anthracite fines in the manufacture of packagedThe experimental loss of packaged fuel covered by this report were made at a commercial plant using the Glenn Smith process and ordinarily making packaged fuel from Pocahontas screenings. These lots included several made from straight antimacite mines and others made from various blends of anthracite fines with four different bituminous coals. In all cases an asphalt binder was used. Determinations of the physical properties and the cobustion characteristics o the various samples of packaged fuel were made by the. Bureau of Mines at the Central Experiment Station.The physical tests indicated that a packaged fuel of sufficient strength for ordinary handling can be made from straight anthracite coal or from a wide variety of blends of anthracite fixes with bitunimous coal, using asphaltic binder. However the combustion tests indicated that packaged fuel made from anthracite alone tended to crumble excessively during burning and that as much as 30 to 50 percent of a caking coal may be required In the mixture to produce a block having satisfactory combustion characteristics.The authors wish to acknowledge the. splendid cooperation of Messrs. H. W. Kelly, J. L. Mooney and C. H. Stoss of Columbus, Ohio, who were chiefly responsible for obtaining the materials and making all the arrangements necessary for the production of the packaged fuel for testing.Thanks are due to the officials of Carnegie Institute of Technology for the use of their Olsen. Testing Machine and to H. M. Cooper and W. A. Selvig of the Bureau of Mines for analyses and tests."

May 1, 1946

By D. A. Reynolds, J. D. Davis

During early development of the blast furnace, Connellsville coke made entirely from Pittsburgh-bed coal proved to be an excellent fuel. The need for blending coking coals arose as the industry grew and it became necessary to carbonize coals having voking properties inferior to those of Pittsburgh coal Most coals carbonized today in continental Europe and this country are blonded: This practise has improved the quality of coke and permitted the utilization of coals that would yield inferior coke, if carbonized sepa- rately, The depletion of the world's better coking coals, which has been noted by leading coal technologists,2/4/wes accelerated during the recent war and. It is important, therefore, that reserves be evaluated and conserved. In the principal, steel-producing sections of this country, Pocahontas coals have been blended so extensively that the terms "low-volatile coking coal": and. "Pocahontas" have become virtually synonymous. Other low-volatile coals. have been used to manufacture metallurgical coke and will be used more extensively as, the supply of the better known and more accessible Pocahontas coals decreases. Recognizing the need for augmenting the supply of high-rank coking coals, the Bureau of Mines has included both low- and medium-volatile coals in its Survey of the Carbonizing Properties of American Coals, which was started with the cooperation of the American Gas Association in 1929. Twenty coals, 12 of low-volatile and 8 of medium-volatile rank, have been blended with high-volatile A Pittsburgh-bed coal, and five standard low- volatile coals have been blended with various high-volatile coals. Most of the results of carbonization tests of these coals and their blends have been

May 1, 1946

By Richard L. Sayrs

"The Stiner zinc prospect near the north boundary of Union Tennessee, and the Bunch Hollow property 5 miles northeast in Claiborne County, Tennessee, were diamond-drilled by the Bureau of Mines during the period .September 1, 1944, to February 22, 1945. Seventeen holes totaling 5,687 feet were completed, 13 of which, totaling, 5.083 feet, were on the Stiner property and the remainder, totaling 604 feet, at Bunch Hollow.The Stiner prospect is about 1 mile east of the old workings known as ""New Prospect"" or ""Lead Mine Bend."" The Federal Geological Survey made a study' of the area early in 1944. The prospect was first visited in August 1944 by Bureau of' Mines engineers3/ accompanied by members of the Federal Geological Survey.4/ The locality is reached by traveling State Road 33 north-about 9 miles from Maynardsville, Tenn., thence northwest about 7 miles by an improved county road that leads to the mine (fig. 1). The tract comprises an area of about 181 acres held by G. S. Stiner of Sharps Chapel, Tenn.; it is now under option to the Universal-Exploration Co. of Jefferson City, Tenn.The Bunch Hollow property, about 5 miles northeast of the Stiller prospect, was also studied by the Federal Geological Survey previous to being;Visited by Bureau of Mines engineers in August 1944. It is reached by traveling north from Maynardsville, Tenn., on State Road 33 about 13 miles, thence northwest by county road 6 miles to the property (fig. 1). The last 3 miles of the county road are in poor repair but are passable during the entire year. The property comprises an area of approximately 300 acres and is held by the imperial Mining Co., Pressman's Home, Tenn.Few reliable data are available as to the history of the Stiner prospects themselves. However, the New Prospect mine, 1 mile west, has had a colorful past, This mine was opened in 1883 and was worked intermittently until 1918, by which time more than 65,000 tons of concentrates had been shipped. No further work was done until 1942, when the mine pillars were robbed and 1,900 tons of ore averaging 25 percent zinc was shipped to the New Jersey Zinc Co., Austinville, Va."

Apr 1, 1946

By J. Wade Watkins, Joseph W. Horne, Arthur Matzick

"A successful procedure for the recovery of a valuable product from weathered tank-bottom settlings has been developed in the laboratories of the Bureau of lines and used in a field pilot plant. These heavy emulsion settlings, generally regarded by the industry as waste material, have usually been drained into open pits or storage ponds and eventually destroyed.Laboratory examination of the waste material shows it to consist essentially of a ""water-in-oil"" emulsion containing a considerable volume of congealed ""paraffin."" This paraffin is mainly high-melting-point wax; known in the industry as microcrystalline wax, for which there is an increasing demand.Because of the physical properties of this wax, the tank-bottom settlings are not responsive to conventional methods used for demulsifying ordinary crude-oil emulsions.The work upon which this report is based was conducted by the Bureau of Mines in cooperation with -the Kansas State. Board of Health and with special cooperative agreements-with the Cities Service Oil Co, Bartlesville, Okla., and the Bareco Oil Co,. Barnsdall, Okla. The studies were made under the general supervision of R. A. Cattell, chief engineer, Petroleum and Natural-Gas Division, Bureau of Mines, Washington; D. C., and H. C. Fowler, supervising engineer, Petroleum Experiment Station, Bureau of Mines, Bartlesville, Okla., and under the direct supervision of Ludwig Schmidt, senior petroleum engineer, Bureau of Mines, Bartlesville, Okla.Gratefully acknowledged are the assistance and cooperation given by the Cities Service Oil Co. of Oklahoma and especially by M. J. Kirwan, manager of production, and by Q. E. Beecher, general superintendent of production, Bartlesville, Okla., and to members of their staff at Oil Hill, Kans.The assistance and suggestions of V. R. Oakley, general superintendent, E. R. Wiles, director of research, L. G. Willis, field engineer in charge crude-oil supply, and Gerald DeWalt, chief chemist, and his staff of the Bareco Oil Co., Barnsdall, Okla., were of much value in the laboratory and recovery work."

Mar 1, 1946

By Dupuy. Leon W., R. T. C. Rasmussen, W. A. Calhoun

"INTRODUCTION For many years it has been known that low-grade manganese deposits occur in the bluffs along the Missouri River Valley. Frequent attempts have been made to develop the ore and to produce a marketalble commodity but they have had little success. Under pressure of the war emergency and the shortage of manganese, the attention of the Federal Bureau of Mines was directedtoward the deposits.Manganese-bearing shale occurs from a point near Pierre, S. Dak., down the river to the Rosebud bridge near the Nebraska line (1).5/ The Bureau of,confined its work to the more accessible central portion of the deposits near Chamberlain, S. Dak. The ore occurs principally as concretionary nodules in the form of iron and manganese carbonates (manganosiarite and perhaps some manganocalcite; rhodochrosite has not been identified). At the surface the carbonate is often broken down so that the oxide of manganese gives the nodules a black The matrix or host rock is generally known as Pierre shale, composed of ""interbedded layers of bentonite, an altered volcanic ash, and dissemi¬nated bentonite particles,"" (2) and montmorillonite-beidellite clay minerals (3). The shale weathers to the very sticky gumbo characteristic of South Dakota and well-known to hunters and travelers in the area.The area selected for the experimental mining and pilot-plant work discussed in this report lies about 8 miles westerly from Chamberlain and is a few hundred feet north of U. S. Highway,16, on land owned or controlled,by M. Q. Sharpe of Kennebec, S. Dak., and the General Manganese Corp."

Feb 1, 1946

By H. G. Doll

'This paper discusses a method and apparatus for determining the dip of formations traversed by a drill hole, by means of electrical measurements in the hole. The process consists in recording the Spontaneous Potentials present along three oriented generatrices in the hole. By comparison of the three curves thus obtained, after application of a correction factor to compensate for any deviations of the hole, the dip angle and the dip direction are determined. Excellent accuracy is obtained for dip angles over 10°. Because the method is simp1e and the apparatus rugged, the measurements are rapid and reliable; consequently, they can be made at all the levels that are of interest at any time after the well has been drilled. Mechanical cores are not needed to evaluate the dips. A convenient, time-saving procedure is to perform the dipmeter survey at the time the electrical log is taken, using for both operations the same cable and truck. Actual examples of results obtained in wells of the Gulf Coast area are given. Introduction The problem of determining the angle and direction of the dip of the strata traversed by a drill hole has practical interest, and sometimes vital importance, which need not be emphasized to the oil industry. The need for that type of information has existed ever since wells have been drilled. Certainly it has not subsided, in spite of the numerous inventions and improvements made in other fields of the art of drill-hole exploration. The few examples given in this paper are but illustrative of this fact. In the past, methods have been devised, and used, to solve this problem, but generally they have met with limited success, possibly because they failed more or less to answer the requirements of a modern age for fast yet accurate measurements. If accurate, the results were obtained at the cost of very tedious and lengthy operations. The new S. P.* dipmeter service offered to the oil industry is the result of exhaustive and in this particular field. In 1032 a dipmeter and electromagnetic teleclinom-eter service was made available. The apparatus employed then was of a rather delicate and costly construction, and the measurements had to be made with precautions sometimes difficult to secure on the rig. Although the information given by the electromagnetic dipmeter was limited to the direction of the dip, very interesting results were obtained in California, Trinidad, Venezuela, Rumania and, most notably, in the Netherlands East Indies.+ Apparatus The S. P. dipmeter surveys present none of the drawbacks mentioned above. The apparatus is rugged and free from constructional complications, therefore well adapted to field use. This, combined with the new, basically simple approach to the problem, explains the rapidity of execution of the measurements. The results are remarkably accurate and they are complete, giving the

Jan 1, 1946

By Norris Johnston, Carrol M. Beeson

The gravimetric-vacuum distillation method was developed to permit rapid and accurate determinations of the oil-water ratios of small samples or sands containing little oil. In addition, the samples usually are so well cleaned and so little altered by the distillation at reduced pressure that rapid estimations of other physical properties may be made with the evacuated cores. Requiring only elementary glass-blowing technique, the distilling tubes and traps used in determining oil-water ratios were easily fashioned from the usual glassware. A sketch and description are given of the necessary apparatus, including the cylindrical electrical heaters. The procedure, requiring about 40 min., consists in raising the temperature and maintaining it between 675' and 725°F. for at least 10 min. while the pressure is held between I and 2 mm. Hg. The fluids condensed in the trap (cooled by a mixture of kerosine and solid carbon dioxide) are separated in a centrifuge and the volume of water is recorded. Determination of changes in weight with an analytical balance of all parts of the apparatus permits computation of weight of oil distilled and total weight of oil recovered. Introduction In determining the oil-water ratios of core samples, distillation at atmospheric pressurel-5 has proved to be sufficiently reliable for samples containing moderate quantities of oil. Since small samples and sands with little oil are encountered, how- ever, it appeared advisable to develop a method that would be applicable under these circumstances. Thegravimetric-extraction procedure1,6-9 undoubtedly is very reliable and could be used in all tests, but the time consumed in the determination would often delay field operations. This would be especially true when dealing with tight sands or viscous oils, both of which retard the extraction process. Accordingly, the gravimetric-vacuum distillation method was developed in order to combine the good features of both of the older methods; that is, accuracy and speed. By reducing the pressure, it was found possible to perform the distillation at a temperature that permits the use of glass apparatus, all parts of which can be weighed on an analytical balance. Thus, the fluids may be removed quickly from the core, the water is readily trapped and measured, and the loss in weight of the core is easily determined. In addition, the total weight of material condensed in the distilling tube and in the trap provides a method of determining the oil-water ratio that is practically independent of the one involving the loss in weight of the sample. The use of vacuum not only permits as much accuracy as does the gravimetric-extraction process, but it actually allows an increase in speed over the atmospheric-distillation method, because of the time required to cool the metal pots from about 1200°F. between runs. More important yet, the innovation makes possible the almost immediate reporting of permeability, and saturation, which is impossible

Jan 1, 1946

By William E. Schoeneck

This paper presents the problem of oil-well abandonment as a group of studies involving the compilation of physical well data, the use of special curves, maps, and interpretative Procedures, in order that operations can be analyzed and means for reducing costs can be effected. Methods for the calculation of the economic limit of production and resultant oil reserves are suggested in order that profitable production may be continued and premature abandonment prevented. INTRODUCTION Purpose Extensive studies have been made and much has been written on the procedures for prospecting, drilling, completion, production and repair of oil wells, but the writer has long felt the need for a study of the procedure that should be followed when considering the abandonment of a well. The production from numerous well bores of a fluid material (a circumstance peculiar to the oil industry) that is continually decreasing in quantity leads to an increasing ratio of operating cost to production. It is for this reason that oil fields are not abandoned as a whole and detailed consideration of each well is required before it can be determined whether more is being expended than will be returned On any well or lease in question. It is the purpose of this paper, therefore, to compile, correlate, and present all matters worthy of consideration in the problem of oil-well abandonment; to suggest interpretative procedures based on such compilations, to the end that reliable estimates of reserves and life may be obtained; to show, as a result of such interpretative procedures, the possibilities for corrective measures conducive to economical production, thereby extending both profitable reserves and length of life. Scope and Approach Compiling data and outlining a study having the complexity of the problem at hand are naturally subject to the personal experiences of one who undertakes the study; however, the chosen approach and grouping of the subject material may be helpful in the consideration of abandonment problems. Consideration has been given to wells that make gas and water incident with the production of oil; but consideration has not been given to either gas wells or condensate-producing wells, for wells of the latter type have sufficient problems to warrant separate investigation. The major subdivisions of this paper-— physical considerations and economic considerations—do not imply that either of these phases can be considered independently, but rather that the two are mutually dependent and are the component parts of an engineering study.

Jan 1, 1946

By Robert S. Moehlman

Is recent years, exploration and development by diamond drilling has become a popular attack on the problem of finding new ore shoots and developing extensions of known shoots. Diamond drilling has been used in recent years in extensive sampling of disseminated copper deposits, in preference to churn drilling. At the Harvard gold mine, near Jamestown, California, Philip R. Bradley, Jr., general superintendent, reports that: "The Harvard work was a singular example of the reliance that can be placed on diamond drilling in evaluating an ore body." Drilling at the Harvard mine will be discussed in a subsequent section of the paper. So popular has diamond drilling become, indeed, that many who have had slight experience with drilling are inclined to regard it as a cheap cure-all. This paper proposes to show some of the limitations on the application of drilling and some of the steps that should be followed in drilling programs to obtain reliable results. Cost oF Drilling Drilling has the advantage, over shaft sinking and drifting, of lower cost and greater speed. As compared with churn drilling, the advantage of bringing up a coherent sample instead of fine cuttings for a sample is obvious. Diamond drilling is generally more expensive, however, and more engineering effort is required in combining the average of core and sludge samples. Exploration of drift walls by hammer drills to a depth of less than 30 ft. is generally cheaper than diamond drilling, but beyond this depth the diamond drill is cheaper and more efficient. The principal factor in determining cost of drilling is the character of the ground drilled. Broken ground with many fissures is most expensive to drill. Hard ground is less of a problem with diamond drills than with ordinary machine drills. Hardness or softness affects only the speed of drilling. Caving, easily washed, sandy or clayey ground requires continual cementing and casing, which is the greatest cost problem. Thus, soft, incompetent ground is more costly to drill than hard, massive ground. Cost of drilling per foot in good to fair ground varies from less than $I per foot, achieved in some districts in Ontario, the Mother Lode, and Missouri, to $5 per foot in many western states. In bad drilling ground, costs may range from $5 to $15 or more per foot, thus approaching the cost of drifting. Other factors that increase the cost per foot are: I. Short total length of hole drilled, so that the cost of moving in crews and equipment must be spread over a relatively few feet. 2. Cost of drilling per foot increases with depth beyond about 500 ft.. as more time is consumed in pulling rods' 3. Cost of preparing drilling stations, getting air underground to stations? etc' 4. Inaccessibility and lack of water on the job make for higher costs.

Jan 1, 1946