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By Gunhild Hennum, Tewodros Tefera, Gisle Håland, Annette Jahr

"Abstract The Gudrun field is located west of Stavanger in the North Sea at water depth of 109 m. A jacket substructure was selected to support the topside and was installed in 2011. The jacket shall be able to support 16 of 0.762 m (30 in) diameter conductors and is equipped with a drilling deck to allow for pre-drilling by a jack-up rig through the jacket. In general the soil conditions below mudline comprise of a thin top layer of very loose to dense sand overlaying several layers of sandy clay, ranging in stiffness from firm to hard. Below some 30 m depth the soil consists of layers of medium dense to dense silty sand overlaying very hard sandy clay containing thick beds of sand to 100 m depth or more below mudline. The jacket is secured to the seabed by twelve 2.438 m (96 in) diameter steel pipe piles, three at each pile cluster located at the four legs of the jacket at sea floor. Different design methods were used to determine the pile penetration depth. Pile drivability was evaluated using best estimate and upper bound soil parameters. The pile driving and blow count record show that the target penetration was reached as predicted. This paper discusses the different methods used to determine the pile capacity, target penetration depth and the drivability analyses made for the Gudrun jacket piles. The soil resistance during pile driving is back-calculated from the pile installation data and compared with the prediction made.IntroductionThe Gudrun platform is located west of Stavanger in the North Sea at water depth of 109 m. A jacket substructure was selected for the Gudrun platform. The general Gudrun platform jacket configuration is to a large extent dictated by the topside layout, the requirements for support points enclosing the well slots and access for the jack-up rig. The Gudrun platform jacket is a traditional 4 legged structure with a vertical side towards the jack-up rig. At the seabed the jacket is quadratic with a base dimension of 40 by 40 metres. Figure 1 shows the Gudrun jacket during load-out from the fabrication yard to the transport barge. At the site the jacket was lifted off the barge, upended and placed on the seabed by the installation vessel. The jacket is secured to the seabed by twelve 96"" (2.438 m) diameter steel pipe piles, three at each pile cluster located at the four legs of the jacket at sea floor. The target penetration of the piles is 47 m."

Jan 1, 2014

By Tiziana Apuani

The study refers to an area of about 70 km2, extended in the Italian Central Alps along the the San Giacomo Valley where different civil and mining works are present The regional geological setting is related to the Pennidic Nappe arrangement, characterized by the emplacement of sub-horizontal gneissic bodies resulting from the Mesoalpine isoclinalic folding of crystalline basements, emplaced throw East, and separated by matasedimentary cover units. The investigated geological rocks, belong to the ?Tambò?Unit, overlapped by its meta-sedimentary cover and by the ?Suretta? Unit. The tectonic contact gently dips to the E?NE. The valley, furrowed by the Liro Torrent, follows a N?S striking tectonic lineament, almost parallel to the nappe contact. A number of more then 70 sites, distributed in the studied area, were chosen and detailed structural and geomechanical field surveys were performed to characterize the rock masses, its intact rock and discontinuities. The procedure identifies the number of joint sets, their representative orientation, the set spacing, the type of movement, the amount of dilatation, the degree of alteration, the roughness coefficient, the presence and nature of infill. Rock mass quality indexes, such as the Rock Mass Rating (Bieniawski, 1989) or the Geological Strength Index (Hoek et al. 2002) have been evaluated in each surveyed site. The work is a contribute in assessing how the geometrical and geomechanical properties of the rock masses can be regarded as regionalized variables. The spatial distribution of these properties is a function of the geological and structural phenomena at which the rock masses have been subjected. The presented geostatistical analysis regards the spatial variation of the orientation of the most representative joint set.

May 1, 2009

By Gordon B. French, Donald E. Garrett

INTRODUCTION Crude oil reserves in the United States are still very large, even though for many years they have not been sufficient to supply our entire domestic requirements. They are continuously being depleted as oil is pumped from the ground, but new discoveries and improved secondary and tertiary recovery methods are helping to reduce the rate of depletion. It is thus a slowly diminishing resource, but even as it is being consumed, immense reserves of oil are left behind as the so called "un-recoverable" portion of petroleum formations. Most oil fields can only obtain a 15 to 40% recovery of the original reservoir, and it is widely quoted that there are still about 300 billion barrels of this un-recoverable oil still in place (Mauch, 1980, etc.). With the present comparatively high oil prices, and the possibility of even higher future prices and short supply, this oil becomes an interesting potential reserve. Mining the petroleum formation would be one means of recovering at least a portion of this oil. The concept of oil mining is neither new nor limited to conventional oil fields, since the procedure could be equally employed with the otherwise difficult to produce heavy oil deposits, and the solid or semi-solid tar sands and diatomaceous hydrocarbon formations. Estimates place the U.S. tar sand resource at about 30 billion barrels, and heavy oil at 5-10 billion barrels (Unitar, 1982). Figure 1 graphically summarizes the heavy oil reserves based upon formation depth and characteristics, while Figure 2 shows their location. It is apparent that the preponderance of reserves are in California and Texas, but that they also occur in many other states. The major companies engaged in oil recovery from the heavy

Jan 1, 1983

Mine drainage and mine reclamation are topics of major interest to the mining industry, federal and local governments, and the general public. This publication and its companion three volumes are the proceedings of a conference held in Pittsburgh, Pennsylvania, April 24-29, 1994. There were twelve sessions (69 papers) that dealt with mine drainage, including modeling, geochemistry, prediction, treatment, control strategies, characterization, hydrology, and case studies. These sessions comprise volumes 1 and 2. The six sessions (34 papers) that dealt with reclamation and revegetation of disturbed lands are included in volume 3. Volume 4 includes the six sessions (34 papers) that dealt with such topical issues as fires at abandoned mine sites, subsidence, hydrology, mine wastes, and policy. Poster session presentations are represented by 49 papers and 92 abstracts that have been placed in the back of volumes 2, 3, and 4, consistent with the subject of that volume.

Jan 1, 1994

By E. R. Maize

[In %-port of Invcstiptionn 7452 ,g dcniing with roof ~wet,ent in the Cmcibla r~ine, rof&apos;erence .,as m.da to the f~ct tiwt timker decny war, bsing studied at tho tine of writing. Thic napor, written a3er completion of that ~tudy, describ~s t1l.e ~mrl&apos;: and sunlharizea the fiats obtained. Ifhen tlle stu* oi roof novement bras be,- at Cxcible tw igeas \%.ere a6-r;incsd. on decay of tiriber Q: scne of :he olficialr;: (I.) 9:la.t timber decay v:as unustmlly rapid in ,tho Ciuoiblc mins, ,m?. ((2) that timber coated with rock ri..~st deixiyad morrl mpirlly thnn those %hat vsrc not so coated. Thsx ::ore no records by which tkeso &apos;iaeas could &apos;L;e tertcc?, ard it cnpsarefi vise to make a limite6 in- vo3tiption, p~.rticu!.ai.ly of +.he effect of roc!< dusting on decny, as rock ductirg is nn importnnt mer-ns of ~rc-,rcnt?;~g cad-dust eql-osions. ]

Jan 1, 1941

By P. A. Witt

"Highland Valley Copper is a conventional truck-shovel mining and flotation concentrator operation located 75 km southwest of Kamloops, British Columbia (Fig. 1).The ore is situated within a porphyry copper deposit and is mined at a rate of 135,000 mt/day from two separate open pits. The nearby mill produces concentrates containing 375 million pounds of copper and 5 million pounds of molybdenum metal yearly. In the Valley pit, head grades are roughly 0.40% Cu at a 0.23% Cu equivalent cut-off. The Valley pit strip ratio currently sits at 0.55:1 with waste quantities made up of separate rock and unconsolidated overburden units. From the mill, concentrates are trucked to nearby Ashcroft and then hauled by rail to ocean port facilities in Vancouver. The mine employs 950 people and is planned to operate until 2009. The operation is a partnership between Teck Cominco (63.9%), BHP Billiton (33.6%), and others (2.5%). Management is shared by the two principal owners and directed by a management committee."

Jan 1, 2005

By Charles Zahn

Direct mass spectrometric determination of alcohols in the presence of hydrocarbons has not been possible because of the similarity of hydrocarbon and alcohol mass spectra. Experiments have demonstrated that by converting the alcohols to their trimethylsilyl derivatives, characteristic mass spectra are obtained free of interference from hydrocarbon ion fragmentation. Hexa- methyldisilazane is the reagent selected for the conversion, An improved method of preparing the reagent is given, Mass spectrometric determination of alcohols as trimethylsilyl ethers now is not only possible without prior separation from other materials, but the range of the room-temperature mass spectrometer is also extended to include the C10 alcohol region. Water does not interfere because it is converted to hexamethyldisiloxane, which has its own distinctive mass spectral peak, Experience indicates that other compounds such as glycols, amines, and phenols probably could also be determined by mass spectrometry of their trimethylsilyl ethers. Studies on the similar detemination of phenols in coal oils have been started, When mass spectrometry is not available, gas-liquid chromatography of alcohols before and after their conversion to the trimethylsilyl derivatives probably could be performed. The preparation and properties of the trimethylsilyl derivatives of 23 alcohols, 2 glycols, 3 amines, and 1 mercaptan are detailed. INRODUCTION During investigations by the Bureau of Mines at the Pittsburgh Coal Research Center relative to the development of Fischer-Tropsch processes, complications were encountered in the mass spectrometric analysis of alcohols in hydrocarbon oils. The fragmentation peaks of the alcohols and the hydrocarbons were so similar that an accurate analysis was not possible, Since involved separation techniques are necessary to isolate alcohols from hydro-carbons for separate determinations, efforts were turned to the search for a

Jan 1, 1962

By Richard E. Thill

Elastic wave velocities and moduli were determined by both the pulse and resonance methods in a large number of specimens of St. Cloud Gray Granodiorite and Tennessee marble under the same moisture, temperature, and stress environment. Long cylinders were first tested by the resonance method to obtain longitudinal bar and torsional wave velocity. The cylinders were then sectioned in half and tested by the pulse method to obtain the transient pulse velocity. These velocities were later used to obtain various moduli for comparison. Statistical comparisons between the Young&apos;s, shear, and bulk moduli and Poisson&apos;s ratios obtained independently by the pulse and resonance methods indicate that the methods do not give equivalent results in nearly isotropic rock. The amount of difference varies for each modulus, with the least difference (less than 5 pct) occurring in the shear modulus and the greatest difference (as high as 34 pct) in the bulk modulus. Moduli determinations in aluminum show much closer agreement between the pulse and resonance methods than in rock. The discrepancy in pulse and resonance results probably is caused by frequency dispersion effects and by differences in error sensitivity in the various formulas used to calculate the moduli.

Jan 1, 1974

By Ingrid Hann

The Triple Bottom Line ? Economic Sustainability ? Creation of Joint Venture companies ? Planned evaluation of other kimberlites ? Social Sustainability ? Impact Benefit Agreement and Participation Agreements ? Education and training initiatives ? Environmental Sustainability ? Environmental management ? Mine closure planning

May 1, 2008

By Ralph B. J, Sadler W. R

Thiobacillus ferrooxidans was shown to catalyse biodegradation of chalcopyrite concentrates. The process was growth associated at normal temperatures (30&#176;C) in dilute acid solution (pH2, H2SO4) in submerged cultures. Approximately 20% of the copper dissolved in 22 days in the presence of T ferrooxidans while less than 0.6% was released when bacteria were absent. In ore column leachates, the iron and sulphur oxidizing species T ferrooxidans, ranged from I04 to I06 cells/ml while exdusively sulphur oxidizing species ranged from I02 to 104 cells/ml. T ferrooxidans predominated below pH 3 while other sulphur oxidizing bacteria favoured higher pH. Organisms were distributed vertically in ore columns according to pH differences, resulting from gradual acid consumption by gangue, during trickle irrigation.There was a sequential development of bacteria in leachates from fresh ore irrigated with water only. High pH sulphur oxidizers were always present, low pH sulphur oxidizers appeared within a week while T ferrooxidans took 50 days to show up. Routine monitoring of bacteria in dump leachates provided a qualitative indication of events in otherwise inaccessible ore bodies.

Jan 1, 1981

By C. Pritchard

John Marks said in his acceptance of the Hartman Award in 2008 ? ?I guess that without the occasional complaint, your mine is probably over-ventilated? (Marks, 2008). Miners are seldom in this situation and often spend much of the time trying to find enough air to keep the operation running. With examination there are some things that can be done to make the best use of ventilation systems. Should there be surplus air, in which some of these options may result - financial and other benefits can be obtained. Some of the issues mine operators have needed to address recently are increased airflow requirements to dilute diesel particulates in metal and non-metal mines. Also, operations are faced with demands from reserves that are deeper, hotter and further away from fans and shafts, not to mention increased production demands. Mine ventilation air is a costly commodity, especially by the time it has been heated or cooled and moved to the bottom of the shaft and through the mine airways. Most of the options presented in this paper are useful for metal non-metal operations but some may be applicable to coal too. OPTIONS FOR IMPROVEMENT Some of the areas to be addressed are shop ventilation methods, auxiliary equipment areas, dedicated intakes and returns, optimizing development, examination of mine airway utilization and alternative ventilation methods. UNDERGROUND SHOPS First, examine what is being done with the underground shop air. If it is being coursed directly to the returns there may be some potential to better utilize this, in most cases, relatively contaminant free air. Research the legal options for ventilating mine shops. MSHA regulations in 30CFR 57.4761 (1) allow the following options: To confine or prevent the spread of toxic gases from a fire originating in an underground shop where maintenance work is routinely done on mobile equipment, one of the following measures shall be taken: use of control doors or bulkheads, routing of the mine shop air directly to an exhaust system, reversal of mechanical ventilation, or use of an automatic fire suppression system in conjunction with an alternate escape route. The alternative used shall at all times provide at least the same degree of safety as control doors or bulkheads. Discussion This regulation gives some operators flexibility in ventilating underground shop facilities. If shop air is to be coursed through the work area, and then directly to the mine return, the question should be asked ? is the quality of air good enough to be reused in the mine, and if so, what are the risks? Can the risks be accommodated and managed to accomplish the change? If so, a considerable increase in mine level airflow could be attained by reusing shop air. Clearly, regulations are a minimum standard, and can be exceeded. Metal non-metal mine regulations are not as specific as coal due to the multitude of different mining methods and conditions utilized. Risks must be thoroughly examined and addressed to assure a safe environment. Issues Determine what contaminants are being produced in the work area ? welding fumes, diesel exhaust, paint fumes, chemicals and solvents, etc. Survey the area and determine exposures. MSHA requires exposure monitoring in 30 CFR 57.5002 (1) of dust, gasses mists and fumes to assure air quality is being met. Perform surveys and examine existing data to quantify personal and area concentrations of contaminants. Often there is adequate circulation such that exposure levels in shop work areas are low. After sending shop air back into the system any contaminants would be further lowered by dilution with other mine intake air downstream. Look at the shop work schedule. If only on day shift, the other two shifts and possibly weekends have no activity or source of contamination to affect the ventilation system. The worst case planning scenario would be a shop fire. Study and simulate how this would affect the mine and shop area. MSHA regulations require an escape route and a fire suppression system be installed and maintained as follows in 30 CFR 57.4671 (1): (d) Automatic fire suppression system and escape route. If used as an alternative, the automatic fire suppression system and alternate escape route shall meet the following requirements: (1) The suppression system shall be? (d)(1)(i) Located in the shop area; (d)(1)(ii) The appropriate size and type for the particular fire hazards involved; and (d)(1)(iii) Inspected at weekly intervals and properly maintained. (2) The escape route shall bypass the shop area so that the route will not be affected by a fire in the shop area. Case Study In an underground room and pillar mine, active mine workings were advancing further away from the mine shaft with deteriorated returns and leakage having a negative effect on ventilation airflows to the face. Mine level airflows were 236 m3/s (500,000 cfm) and shop airflows were 24 m3/s (50,000 cfm) (see Figure 1A). No additional capacity was available at the main surface fan. A solution was to utilize the shop air then send it to the mine areas instead of directly to the return. Considerable information on shop air quality and exposures from many years of operation was examined and no negative data was discovered. A risk analysis determined that moving forward with a shop air reuse program was desirable. A plan was developed, analyzed and decision to proceed approved by mine management. The change was simulated on the computer with the USBM/MTU MFire program before being implemented. This included utilizing fire scenarios to examine potential exposures to inby mining sections and plan escape routes. A monitoring system was designed and installed in cooperation with the US Bureau of Mines to monitor carbon monoxide

Jan 1, 2009

By V. A. Leach, J. R. Johnson

The calculation of the dose to the bronchial epithelium, lungs and other body tissues from exposures to airborne radon and thoron daughters requires a knowledge of the pattern of deposition in the respiratory system and clearance from it. Exposure to radon or thoron daughters is measured in units of Working Level Months (WLM), which is independent of the aerosol particle size, the fraction of daughters that are attached to the aerosol and the degree of disequilibria between the daughters, and age and breathing rate of the subject. These factors will influence the deposition and clearance, and hence dose. It is therefore of interest to find the relationship between WLM and calculated dose as a function of aerosol size, unattached fraction, and disequilibria, and of age and breathing rate, and to define ranges for these parameters for which WLM is an acceptable measure of the risk. This presentation briefly reviews the two dosimetry models being considered by a current Nuclear Energy Agency (OECD) Working Group, and using these models, defines limits on parameters for which the WLM is applicable.

Jan 1, 1981

By R. A. Cattell

A technologic group such as the Petroleum and Natural Gas Division of the Bureau of Mines, which conducts research on many of the complicated and frequently interrelated problems of extracting crude oil and natural gas from the ground, transporting them to market or to places for subsequent treatment, and manufacturing products, should report progress from time to time. Engineers and others who apply the results obtained by this division are closely associated with its personnel, because may of the problems are attached cooperatively with groups in industry. Some of this cooperation is formal, as exemplified by work now in progress under cooperative agreements with the States of Oklahoma, Kansas, and others, but much of it is informal, prompted by the desire to be mutually helpful in the public interest. Furthermore, the published reports of the Bureau on subjects pertaining to petroleum and natural-gas technology come to the direct attention of a relatively large number of persons, whose interest in results and appreciation of the value of this type of work have caused them to be kept currently informed regarding available data.

Jan 1, 1940

By R. A. Cattell

A technologic group such as the Petroleum and Natural Gas Division of the Bureau f Mines, which conducts research on many of the complicated and frequently interrelated problems f extracting crude oil and natural gas from the ground, transporting them to market or to daces for subsequent treatment, and manufacturing products, should report progress from time to time. Engineers and others who apply the results obtained by this division are closely associated with its personnel, because many of the problems are attached cooperatively with groups in industry. Some of this cooperation is formal, as exemplified by work now in progress under cooperative agreements with the States of Oklahoma, Kansas, and others, but much of it is informal, prompted by the desire to be mutually helpful in the public interest. Furthermore, the published reports of the Bureau on subjects pertaining to petroleum and natural-gas technology come to the direct attention of a relatively large number of persons, whose interest in results and appreciation of the value of this type of work have caused them to be kept currently informed regarding available data.

Jan 1, 1940

By Paul D. Tomlingson

Part two of this two-part series covers the use of an integrated information system with administrative information, including error and absentee reports as well as open work files. Part one (ME, July, page 650) discussed conceptualizing and developing a maintenance information system. It explained what information is needed to manage such a system.

Jan 8, 1985

H. DEAN JACOT RMCMI PRESIDENT 1987-1988 on behalf of The RMCMI Board of Directors and Officers The Rocky Mountain Coal Mining Institute cordially invites you and your family to attend the 84th Regular Meeting and Convention to be held June 26, 27 and 28, 1988 at Beaver Run Resort Breckenridge, Colorado

Jan 1, 1987

By H. Lowers, P. Hageman, S. Diehl, D. Fey

Understanding relationships between mineralogy, texture, microstructural features, and element distribution and residence in minerals, is critical for accurate modeling of mineral weathering in waste-rock piles. The morphology of minerals and deformation structures, such as veins and faults, are important factors that control: (1) fluid access to the mineral surface to initiate dissolution, (2) the distribution of trace elements, and (3) formation of secondary minerals. We characterized the mineralogy, textures, and chemical properties of waste-rock material at three sites at scales ranging from outcrop to micrometer scale. A comprehensive hand-sample to thin-section scale methodology utilizing light microscopy, scanning electron microscopy, electron microprobe, and laser ablation ICP-MS was used to thoroughly characterize the waste-rock material.

Jan 1, 2007

By Bernard Porter, E. A. Brown

Electrical conductivities and densities of the LiF- UF , LiF- ThF4 , NaF - C1F4 , and NaF - ThF systems were measured as functions of composition and temperature . The specific conductance and density varied linearly with temperature . Molar and equivalent volumes , as well as heats of activation for conductance , were calculated from the experimental data . At 1,000 ° C , the molar volumes ranged from 16 to 40 cubic centimeters per mole and the specific conductance ranged from 9.8 to 2.5 per ohm- centimeter as the actinide metal fluoride concentration changed from 0 to 60 mole - percent . Heats of activation for conductance were 3 to 7 kcal per mole . The data are interpreted on the basis of a semilattice model for the melts .

Jan 1, 1964

This volume constitutes the final report for the Rescue Subsystem portion of the Coal Mine Rescue and Survival System program conducted by the Westinghouse Electric Corporation under contract to the United States Bureau of Mines (Contract Number H0101262 dated Jung 17, 1970). The program was directed by the Special Systems Department of the Westinghouse, Baltimore, Maryland facility. The basic objectives of the CMRSS program were to develop and test hardware to determine the efficacy of a variety of coal mine rescue and survival concepts and techniques. These concepts were drawn from two major- sources: the Request for Proposal from the Bureau of Mines and the final report on the Mine Rescue and Survival Study conducted by the National Academy of Engineering (NAE).

Jan 1, 1971

By R. Venugopal, Saxena. V. K., U. Sankrityayan

"There is a dire need of a technology which can break the mineral interfaces to enhance liberation with minimum energy consumption in mineral beneficiation processes. Understanding of mineral crystal system and interfaces is essential to develop such methodology. So, this study is carried out to find out the role of mineral crystallography in milling and liberation. Data related of mineral crystallography, Vickers Hardness Number, Bond Work Index and beneficiation processes were collected from literature and detailed statistical analysis has been carried out to establish a correlation among these parameters. It was found that atomic weight and cell parameters shown statistically significant relationship with Vickers Hardness Number of minerals, which controls the milling characteristics of ores. Liberation characteristics of five different kinds of ores were analyzed considering the types of interfaces between valuable and gangue minerals. It was found that phase interfaces play vita role in liberation and coarser liberation can be achieved in the minerals of incoherent crystal systems like manganese and zinc ores. Study of this subject can help us to understand the effect of stress wave propagation in solids and its effect on crystal interfaces. It can also help us to design a technology of future to break the mineral interfaces.INTRODUCTIONCommunition is energy intensive mineral processing operation and consumes up to 2% of the total electric power generated in the world. Energy consumption due to comminution is increasing every year as there is growing needs to exploit lower grade ore bodies and process rejects (Blazy et al., 1994; DOE, 2005). Low grade ores require crushing and grinding to liberate the valuable minerals which are further separated from gangues by various beneficiation methods like gravity separation, floatation, leaching etc. Currently, comminution methods are selected based on the reduction ratio and energy consumption but effect of grinding methods on subsequent processing methods specially on liberation also need to be studied to optimize the entire beneficiation process. Most of the attempts made in past to minimize the energy consumption in milling to enhance the mineral liberation were focused on compression mechanism, chemical additives, thermal treatment, microwave treatment and electric disintegration (Kilpelm and Austin, 1982; Norgate and Weller et al, 1994; Bearman et al., 1997; Kumar et al., 2010; Wang el al., 2011; Singh et al., 2012). But the role of mineral crystallography on milling and liberation behavior of minerals not fully explored yet."

Jan 1, 2013