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By G. B. Shea

"INTRODUCTION Much of the recent progress in increasing the efficiency of oil-well performance can be attributed to advancements in the art of cleaning wells. Through research and development by operators and service companies during the past decade, significant improvements in the application of engineering and chemical principles to well-cleaning technology have widened greatly the scope of ""clean-out"" methods to the end that greater ultimate recovery of oil will be attained.This report reviews recent improvements and developments on this important problem in California; it describes also the use of various methods and tools for cleaning wells to stimulate or revive their productivity. Developments in preventing and removing mud sheaths in well-completion operations also are described. The report is based on a field survey, supplemented by data from the technical and patent literature and from manufacturers' catalogs, which contain much valuable information.In preparing the material for publication as a Bureau of Mines report, the author has been fully aware of certain limiting conditions that attend the discussion of a subject such as that treated in this report. The following are examples:1. To a considerable extent, well cleaning in California is done with tools rented from service companies, and their representatives and employees are specialists in jobs of this type. They usually have working experience with their own equipment and methods which greatly exceeds that of persons whose interest has been casual or who have had no opportunity to study the subject in detail in actual practice. Many of the tools and methods are covered by letters patent for the protection that may be in developing and successfully applying these mechanical and chemical means of increasing the production of wells. Frequently several years have been required to perfect a given tool or technique, requiring relatively large investments to establish a service that is remunerative to those who have primary interest in a certain development and at the same time attractive enough to the operators of producing properties (because of greater quantities of oil delivered into the flow tanks) to warrant employment of or contractual agreements with a particular service group."

May 1, 1943

By F. A. Skirvin

Purification techniques were investigated for removing low-level metallic impurities from tungsten hexachloride. These techniques included distillation) fused-salt scrubbing) zone refining) and adsorption. Fractional distillation of tungsten hexachloride was found to be an effective purification method. The impurity levels of molybdenum) iron) nickel) copper) magnesium) and manganese were reduced to provide a tungsten halide sample which contained a total of less than 10 ppm detectable metallic impurities. Purification by fused-salt scrubbing of tungsten hexachloride in a lithium chloride-potassium chloride eutectic produced a hexachloride product which was of approximately the same quality as that obtained by distillation. Zone refining and adsorption did not appear to be as effective as distillation or fused-salt scrubbing.

Jan 1, 1967

By F. P. Haver

A method to recover copper and elemental sulfur from chalcopyrite concen¬trate, using a ferric chloride leach, CuFeS2 + 3FeCl3 ? CuCl + 4FeCl2 + 2S, was reported by the Federal Bureau of Mines in 1971 (Report of Investigations 7474). Since that time, additional work has been done to improve certain steps in the procedure; that is, the recovery of sulfur from the leach residue, the recovery of copper and iron from the leach solution, and the regeneration of the leach solution. It was determined that over 99 pct of the elemental sulfur in the leach residue could be extracted at ambient temperature with an ammonium sulfide solution. Heating the pregnant solution precipitated crystals of rhombic sulfur (99.5 pct purity) and liberated ammonia and hydrogen sulfide for recycle. Copper with a purity in excess of 99 pct was obtained from the leach solution by electrolysis, using a diaphragm cell, with an energy requirement of less than 0.7 kW-hr/lb. Metal was deposited as a weakly adherent powder that could be easily dislodged from the cathode and withdrawn continuously from the cell in the form of a slurry. During electrolysis, part of the Fe(II) was oxidized to Fe (III) at the anode so there was no chlorine evolution. The leach solution was regenerated by direct oxidation of the spent electrolyte with air or oxygen in a turboaerator at 80° C. This precipitated the iron dissolved during leaching in an easily filterable form, Fe203.xH20, and converted the remaining Fe(II) to Fe(III).

Jan 1, 1975

By Tignor E. M.

The Brenneman oil field in Grant District, Hancock County, W. VA., was selected for study by Bureau of Mines engineers because it was typical of many of the smaller petroleum reservoirs in the Appalachian region. In 1906, E. W. Marland & Co. discovered the Brenneman field by drilling a well that readied the oil-bearing .Berea sandstone at a depth of 750 feet and initially produced 200 barrels of oil a day. Most of the oil-productive area (348 acres) of the field was developed in a comparatively short time, and the initial daily production rates of some of the wells were as high as 1,000 barrels of oil a day. Although the field was a prolific producer of oil for several years, it was abandoned in 1923 when the production rate was less than 1,000 barrels of oil a year and 705,000 barrels of oil had been produced. Secondary-recovery operations were started in the Brenneman field in 1927 after useable old wells had been repaired and unsatisfactory wells had been plugged; drilling of new wells was started in 1929. The peak of the redevelopment program was reached in 1942 when 92 oil-producing wells and 26 injection wells were in use; both air And mixtures of air and natural gas were used for injection purposes. It is estimated that approximately 357,000 barrels of oil, equivalent to 1,030 barrels per acre, 105 barrels per acre-foot, 8.5 percent of the total pore volume, or 11.9 percent of the original oil in place will be produced as a result of gas-injection secondary-recovery operations. Engineers of the Bureau of Mines Petroleum Field Office, Franklin, Pa., are studying secondary-recovery projects in the Appalachian region as a part, of the Bureau's secondary recovery research and are reporting these studies so that others: can profit by the experience gained from the operations. In common with most of the other Appalachian oil fields, there was no natural water drive in the Brenneman field. The estimated oil saturation in the Brenneman reservoir at the end of economic gas-injection operation indicates that additional oil might be recovered economically by water flooding and that a pilot flood would be warranted.

Jan 1, 1950

By L. Y. Sadler

This report summarizes the findings of a 9-yr research program, sponsored by the U.S. Department of Energy and conducted by the Bureau of Mines, to evaluate refractory liner materials for coal gasifier reactors. Commercially available refractories were exposed to coal gasifier reactor environments, reproduced in the laboratory with a high-temperature, high-pressure test facility, followed by extensive postexposure evaluation. Thirty-six castable or gunnable refractories and cements and 24 refractory brick were evaluated. The behavior of castable refractories reinforced with stainless steel fibers was also examined. Gas environments that were evaluated included steam, H2, CO2, CO, and typical high-and low-Btu gas mixtures. Exposure pressures ranged from 100 to 1,000 psig, temperatures from 5000 to 1,1000 C, for periods from 50 h to 2,000 h. In some exposures, sodium and/or potassium hydroxide were introduced in order to simulate a high-alkali environment. It was found that intermediate-and low-alumina refractories produced from domestically available raw materials, rather than high-alumina refractories produced from imported raw materials, gave the best service as liner materials and that alkali attack was probably not a serious problem with most refractories. Based on the results of this program, good choices of refractory liner materials for gasifier reactors can be made.

Jan 1, 1984

By Andrew W. Berg

The Bureau of Mines Mineral Industry Location System (MILS) is part of the computerized Minerals Availability System (MAS), a comprehensive data base of known mineral deposits. MILS, the location subsystem of MAS, has become widely used by the minerals industry and organizations with land-use planning and land management responsibilities. Information on more than 135,000 mineral locations and processing plants in the United States is contained in the data base. This information includes the name, location, mineral commodity, type of operation, bibliography, and cross-references for each property or prospect. Computer-drawn map overlays at various scales showing clustered MILS locations and computer printouts keyed to those overlays are available for inspection and reproduction at the Bureau's Field Operations Centers at Juneau, Alaska, Denver, Colo., Pittsburgh, Pa., and Spokane, Wash.

Jan 1, 1979

By Fun-Den Wang

A new approach for evaluating pit slope stability by the limiting equilibrium method has been developed by the Bureau of Mines. The finite element method of plane strain analysis is used to find the stress field of the pit slope structure. This stress field is then used to find the normal and shear stresses along a potential failure surface. The normal stresses are used with the Coulomb equation to calculate the shear resistance. The shear stresses are integrated to determine the total driving force. The factor of safety is evaluated from the ratio of the resisting force to the driving force along a failure surface, and is found to be affected by the elastic material properties, modulus of elasticity, and Poisson's ratio.

Jan 1, 1970

By Wm. F. Netzeband

The purpose of this paper is to present to the operators, in other districts a detailed description of the ruining method used and the results obtained to exploiting one of the zinc-lead deposits of the Kansas-Oklahoma-Missouri district. No. 1. mine is located in the heart of the town of Picher in the extreme northeast corner of Oklahoma. HISTORY The first prospect drilling was done at No. 1 mine late in-1914, and shaft sinking was started early in 1915. Sufficient ore was developed to start construction of the mill in April, 1016, Production begin in August, 1916, and the mine s been producing, except for short periods, to the present time. The property was originally a 40-acre tract, but additional properties have been consolidated with the original one until the mine now covers 200 acres.

Jan 1, 1929

By Oliver Bowles

The use of fire as a source of heat was the first step from primitive existence toward modern civilization, and heat has performed functions of inestimable importance throughout the ensuing ages. The first commercial steam engine invented in 1698 demonstrated that heat was an important source of power, and heat has since become the motivating force for railroad trains and steamboats as well as for machines in multitudes of factories. Aside from its function of supplying power, heat is an agent of vast importance in chemical reactions and engineering processes. Because of the high temperature of steam under pressure, losses by radiation from boilers and pipes become excessive unless the radiating surfaces are covered with insulating materials. Insulation is important also for hot-water pipes and many other types of equipment from which heat may radiate. Radiation losses from heated surfaces increase rapidly

Jan 1, 1943

Develop design and support guidelines for coal mine entry intersections based upon results of integrated field and numerical modeling analyses of structural parameters for improving ground stability. Background Underground coal mines contain a large number of entry intersections. Dome-shaped zones over the intersections are unstable and are often associated with roof falls. These roof falls may occur during mine development, trapping equipment and endangering miners. These high-risk areas of the mine account for 10 pct of the total number of ground-failure-caused fatalities. The falls, ranging from heights of 1 to 20 ft, cause high dilution and slow the advance rates. Stability at intersections is influenced by four structurally interrelated parameters: in situ stress, geological discontinuities and physical properties, intersection geometry, and roof span. Because of the complex interaction of these parameters, the actual mechanism of roof failure may vary considerably, depending upon the roof lithology, rock strength, and stress conditions.

Jan 1, 1990

By G. L. Oldright

[Processes by which silver alone is extracted from ores that also cant contain base metals are usually associated in the mind of the period when mines were changing from the production of noble metals to the production of base metals containing noble metals as a by-product. In this transition period the mixed arcs of the partly oxidized ore zone had to be treated instead of the free-milling ore that had been treated in the past or the deeper-lying sulphide ores that were to be smelted subsequently under improved economic and technical conditions.]

Jan 1, 1929

By William W. Adams

The stone-quarrying industry of the United States, including such related operations as rock crushing, rock dressing, and the manufacture of cement and lime, reported a larger volume of employment in 1934 than in 1933. Reports from the operating companies to the United States Bureau of Mines showed an increase in the number of men employed, number of man-days of employment, and total number of man-hours of labor performed during the year. Moreover, the average worker had a longer period of employment during 1934, the gain amounting to 11 percent over 1933. The increase in employment was accompanied by no increase in accidents for the industry as a whole; in fact, the accident rate for 1934 was a fraction lower than the rate for 1933. In some branches of the industry the frequency of accidents increased, but these increases were more than offset by reductions in rates for other branches. Reports for 1934 were received from 1,403 active plants. The working force averaged 64,331 men for 204 days per man, and the total period of employment for all of the men was 95,258,880 man-hours. Each employee averaged 1,481 hours of work during the year. The total number of hours of labor represented a gain of more than 8 percent, and the average working time per employee showed a gain of 62 hours per man.

Jan 1, 1936

By W. M. Deaton

[Knowledge of the ten?erat~rre to wkich n gas ullder3atur~ted xith re- srplc t to water vapor may be cooled before the water p?f 11 3egin to condense 8 is desirable .and frec-uently iq neceTsarp in nWy resenrch c~d industri~J activities. This tenperrture, the dew point, i s 2 nrrticulnrly innortmt factor in high-pressure gas transmission, PS water cox?-ensate any interfere i with the flow of gos in the line. Sonetimes this interfexnce is due only to the yresence of the liquid water. At other tfncs, under certain condi- tions of pressure and teriperature, the cogdense;? water cn!nhines with the 93 to farm solid .y2: hydrctes. These solid coar~ouncis ma:/ ccllect in sufficient quantit;. to rehce materially the c~xrying cap.citg of the pipe line or ever, to ply thc line coimletelp. ]

Jan 1, 1938

By Michael Rieber

In this study a generalized specification and costing model for high tonnage coal carrying conveyor belts of 3.5 to 100 miles is presented. These belt systems, in modular units or flights, of up to 9 miles in length can be considered in terms of gathering systems. The study format is sufficiently open to allow users to insert their own requirements and parameters. A specific case study is provided. Because conveyor belts are feasible almost anywhere, this study has not investigated any specific route or geographic location. Rather, it has concentrated on setting up an heuristic programming model for conveyor belt facility optimization and cost minimization. The analysis starts with the principle factors involved in the design of the system and their optimization for various cases. This is followed, in Section 5.4, with a factor by factor cost analysis based on industry data and the preceding optimization. The next step is the development of both facility and costing models suitable for computer analysis. Logic flow diagrams are presented at each major analytic step.

Jan 1, 1977

By R. O. Dannenberg

A metallic displacement process, utilizing easily available steel wool or steel window screen, was devised and successfully used for the recovery of silver from waste photographic fixing solutions. Laboratory and prolonged commercial-scale testing established that the iron filament type unit will efficiently precipitate silver, as a high-grade sludge, from acidic waste photographic fixing solutions ranging in grade from less than 1 to over 10 grams of silver per liter. Data and design information are presented to facilitate the construction and operation of a practical unit of any desired size. A smelting process for recovering pure silver from precipitated sludge containing 27 to 80 percent silver was devised.

Jan 1, 1968

By G. M. Kintz

It is estimated that 10,000 lives were lost and $285,000,000 worth of property was destroyed by fire in 1937. Of the 103 fatalities in tie petroleum industry in 1938, 36 resulted from fires and explosions.3/ Everyone can help to prevent the tremendous losses, both in life and property, caused annually by fires and explosions, Forest fires occur every year, in which the tremendously intense heat wave ahead of the flame turns beautiful green trees into blazing torches like so much gasoline, vapor, and jumps over the tops of trees to start fires behind the firs fighters; prairie-grass fires occur, and a farmer in the path of the fire must plow a furrow around his home and outbuildings before the flame reaches them; and frequently automobiles are burned up in filling stations. Persons who have witnessed such sights know better than to throw a lighted match, cigarette, cigar, or hot coal from a pipe out of an automobile or to discard a fire or flame of any type in the forest, in the country, or in the city.

Jan 1, 1941

By V. A. Marple, K. L. Rubow, B. A. Olson

"INTRODUCTION Inertial classification, gravitational sedimentation centrifugation, and thermal precipitation arc techniques that can be used to collect particles for subsequent analysis or for particle classification. The inertial classifiers, which include impactors, virtual impactors, and cyclones, are widely used in the sampling or particles. Settling chambers, which include centrifuges as well as gravitational settling devices, are less widely used. Thermal precipitators arc seldom used.Impactors, in particular, have been used extensively, studied both theoretically and experimentally, and arc the instrument or choice for the determination or aerosol mass size distributions. Many versions or impactors arc available commercially and many more have been designed, built, and used in special studies.Virtual impactors are a more recently developed inertial classifier and possess a feature not round in conventional inertial impactors; namely, that the particles remain airborne after classification compared to the conventional impactor, where the particles arc collected on a solid surface. The feature or keeping particles airborne is important for transporting the particles to other particle-analyzing instruments, or to filters, and in concentrating particles larger than the cutsize in a small fraction of the total now."

Nov 1, 1995

Table XXXIII itemizes the cost associated with the installation of an irrigation system and the application of latex and water in the three experimental areas at Lanse. There were no external labor charges (non- Research Center) except for the installation of the water meter. Cost of pipe and fitting are high because long lines were required at each of the three different locations; these costs were minimized by using plastic instead of metal pipe. Fifteen of the seventeen drums of latex received were used, five drums for each area. [ ] In tank-car lots latex would cost about $0.25/lb so that raw material cost for a 4000 lb/acre application would be in the range of $1,000 per acre. Equipment costs for setting up and irrigation are sensitive to size of area to be irrigated, design of system, and availability and cost of water. A realistic range is estimated to be between $200-500/acre.

Jan 1, 1972

By Mark R. Pettitt

After a long series of laboratory and in-mine tests, a cost- effective, mineworthy, reduced-noise auger miner cutting head was de signed, fabricated, and field-tested by Wyle Laboratories under contract to the Bureau of Mines. Compared with standard auger cutting heads, the new heads reduced noise by 10 dBA at the jacksetter's position and by 6 dBA at the operator's position. This report contains detailed fabrication instructions, including engineering drawings, that show how a standard auger cutting head can be modified to produce a reduced-noise auger.

Jan 1, 1984

By J. F. Barkley

"In the course of the Government's Fuel Economy Survey of its own power plants, studies and tests have been made of various oil-burning equipments under power-plant boilers. There are now many types of burners being offered in the relatively limited field of power-plant use. The majority of the types used may be grouped into two general classes- those using steam to effect the atomizing of the oil, and those using mechanical means.Burners using steam have had the most prominence in this field for a long period. The mechanical atomizing type of burner successfully applied on shipboard, however, pointed to a possible betterment in land work. The vision presented itself of a burner that would need no steam for atomizing that would permit of air inlets or registers compactly arranged as a part of the entire burner, and that would only require the natural stack draft usually available in land boiler furnaces. Hence, rather recently there has been much development along this line, resulting in various types of burners.In Table 1 are grouped test items chosen from many tests showing representative analyses of the products of combustion obtained with various burners installed in various types of furnaces. In all these tests the burners were handled by experts and represent practically the best attainable for that particular arrangement. The boiler efficiencies ranged from 70% to 80%. It will be noted that the burners using steam for atomizing were able to secure slightly better 002 and less 02 without the presence of CO."

Feb 1, 1926