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By J. Douglas, W. T. Ford, G. E. Henderson, I. F. Roebuck

An implicit numerical method is presented for simulating the differential and algebraic relations governing one-dimensional three-phase flow in porous media. The method is based upon compositional representation of the hydrocarbon system. Variable physical properties and water-oil capillary forces are included in the formulation; however, the effect of gravity is ignored. The effects of changing composition and mass transfer are considered through the use of known phase behavior concepts and correlations. The differential and algebraic equations and the numeric approximations to these equations are presented, and the computing algorithm is discussed in detail. This method is used to simulate a single-phase, two hydrocarbon-component gas displacement laboratory experiment. The method is also applied in simulating a solution gas drive and a gas injection problem using a reservoir oil represented as a nine-component mixture. For comparative purposes, the latter two problems also are examined with a one-dimensional volumetric model. The results of the simulation of the laboratory experiment demonstrate the relevance of this method to problems wherein the effects of mass transfer significantly enter the displacement process. The comparison of the results of the volumetric and compositional methods applied to a reservoir system illustrates not only the advantages and benefits derived from examining the hydrocarbon system composition, but also the necessity of this approach in application to a general reservoir problem. INTRODUCTION The advent of large memory, high-speed digital computers enabled reservoir engineers and mathematicians to pool their knowledge in the development of sophisticated techniques for the prediction of oil and gas reservoir performance. These techniques have progressed from volumetric and trend analysis calculations to the development of "mathematical models", or reservoir simulators. These latter models, in general, utilize finite difference approximations to the rather complex partial differential equations that mathematically describe the physics and thermodynamics of fluid flow in porous media. Many forms of this "model" type are available today, and much of the recent literature has been devoted to either improving known methods or developing new techniques for use in these prediction methods. The more advanced techniques in use at this time consist of the solution of differential and algebraic relations that describe a reservoir geometry in one, two or three dimensions and that incorporate reservoir hydrocarbon and water fluid systems that obey specified physical laws, having properties that might easily be measured in the laboratory. This type of model utilizes formation volume factors and other volumetric data, expressed directly as functions of pressure, to represent the reservoir fluid system. Experience gained with this type of simulator, commonly known as a "beta-factor model", has indicated that the approach has many outstanding defects, most of them due to the assumption that those properties measured in the laboratory completely describe the behavior of the fluid system throughout the life of the project under study. The effects of varying hydrocarbon composition and mass transfer between the phases of this hydrocarbon system must, by definition, be ignored. These defects, which may often be ignored in

Jan 1, 1970

By H. Sarvamangala

Biomineralization of manganese on titanium condenser material exposed to seawater has been illustrated. Biom-ineralization occurs when the fouling components, namely, the microbes, are able to oxidize minerals present in water and deposit them as insoluble oxides on biofilm surfaces. Extensive biofilm characterization studies showed that an alarmingly large number of bacteria in these biofilms are capable of oxidizing manganese and are, thereby, capable of causing biomineralization on the condenser material exposed to seawater. This paper addresses studies on understanding the exact role of the microbes in bringing about oxidation of manganese. The kinetics of manganese oxidation by marine Gram-positive manganese oxidizing bacterium Bacillus spp. that was isolated from the titanium surface was studied in detail. Manganese oxidation in the presence of Bacil-lus cells, by cell free extract (CFE) and heat-treated cell free extract was also studied. The study confirmed that bacteria mediate manganese oxidation and lead to the formation of biogenic oxides of MnO2, eventually leading to biomineralization on titanium surface exposed to seawater.

Jan 1, 2008

By K. Saikiran, A. R. Nalla

Longwall management, regular shield maintenance, and evaluation of ground control problems can be performed using real-time shield monitoring program. Based on real-time shield pressure data, evaluation of intensity and interval of periodic weighting, estimation of time-dependent pressure increase and the effects of geologic anomalies can be obtained. In this study, full-face shield pressure data of over 457 m (1,500 feet) of face advancement is analyzed to evaluate shield response in the presence of surface lineaments, floor undulations, and multiple main roofs. Shield pressure increase due to web cutting is also correlated with setting pressure during periodic weighting and normal time. In addition, time-dependent pressure increase rate on Sundays and holidays is also correlated with time average pressure and the location of previous periodic weighting.

Jan 1, 2000

By R. A. Ixer, R. A. Lord, H. M. Prichard, A. J. Boyce, P. McConville, C. T. Pillinger, I. P. Wright, J. Maynard

Analysis of 62 samples show that the sulphides throughout the igneous stratigraphy have a magmatic signature, with the exception of the uppermost gabbros and the lowermost basal thrust talc-carbonate lithologies. Mean delta-34S values for whole-rock samples from harzburgites, dunite pods in harzburgite, crustal dunites and wehrlites, the main and high-level pyroxenites and gabbros suggest that the primary sulphides derived their sulphur from a magmatic source enriched in 34S. This finding is compatible with the proposed origin of the ophiolite above a subduction zone. Values for pyrite mineralisation in the uppermost part of the gabbros are thought to result from precipitation from a seawater-derived fluid, while isotopically light sulphur in the basal thrust could have been introduced from underlying metasediments. The replacement of pentlandite by heazlewoodite has not led to sulphur fractionation

Jun 19, 1905

By E N. Isaev, L E. Levin

New data on the geology of the Late Jurassic to Holocene sediments cover of the World and associated mineral resources (oil, gas, ferromanganese nodules, ores of massive sulphides and other metals) have been compilled in the Atlas at scale 1:25,000,000 and 1:10,000,000. The work was performed by scientists from four Institutes of Russia (VNIIzarubezhgeologia, VNIIoceangeologia, Vernadsky Institute of Geochemistry and Analytical Chemistry of theRussian Academy of Sciences and Geological Institute of the Russian Academy of Sciences). The Atlas shows variation of thickness and formational composition of the large complexes (Upper Jurassic-Early Cretaceous, Upper Cretaceous Eocene, Oligocene-Neogene, Pliocene-Pleistocene), distribution of oil/gas and ore deposits in each complex, data of deepsea drilling (leg 1-130),  thermo-pressure condition in the sedimentary basins within Circum-Pacific Rim.

Jan 1, 1995

By R. Ordóñez Olivares

This manuscript focuses on the design and development of steels for the railroad industry and methods of testing them. Here are summarized the results of research focusing on alloy development and design, with particular focus on advanced rails and wheels. The high-performance steels are characterized for their mechanical and service characteristics. The relationship between properties and cleanliness is discussed and compared to the regular railroad steel. Some of the tests presented are standard tests that are complemented with the nonstandard test recommended by the Association of American Railroads (AAR) and recommended modifications of this. The paper presents the results of metallurgical analysis, mechanical, and residual stress tests. The laboratory methods include microstructure, residual stresses, tensile, hardness, fracture toughness, and microcleanliness tests.

Jan 1, 2013

By Steve Colburn

The CRITERION Survey Systems utilize both theodolite mounted and hand held reflectorless distance meters. These are eye safe, easy-to-use, and specifically designed to endure the harsh environments characteristic to the mining, quarry and explosives industries. Survey data collected by the systems is digitally stored in a ruggedized data collector and then processed with a specialized, Windows-based, interactive software program which can be run on any standard PC.

Jan 1, 1997

By Clarke E. Schuetze

This project had as its objective the experimental investigation of water capsule production utilizing the Southwest Research Institute's submerged nozzle encapsulation apparatus (U.S. Patent 3,389,194). Initial efforts on this project involved nozzle configuration and shell formulation optimization. The shell formulation developed on a prior program was modified during the course of the project to obtain the best balance of capsule breakage resistance and water retention. Subsequent effort centered on determining operating conditions which would produce the best quality capsules for each candidate shell formulation as determined by laboratory tests. Some preliminary work was done to increase the production capacity of the encapsulation equipment. The program was extended with major emphasis concerned with scale-up studies of capsule production capacity and the treatment of problems associated with grouting cartridge fabrication. During the course of the program, water-containing capsules were produced which have good long-term water retention, block resistance and adequate strength. Using a single-nozzle design, a production capacity of 15.9kg (35 pounds) per hour was demonstrated to give acceptable capsules based on initial results.

Jan 1, 1978

By Foster Fraas

One of the lithium minerals most widespread in the earth's surface is spodumene (Li20-A1203-4Si02), a lithium aluminium silicate. For some time, deposits of this mineral were known to exist in the Black Hills of South Dakota, but it was only quite recently that Hess4/ pointed out the great magnitude of the low-grade deposits in forth Carolina. The theoretical lithia (Li20) content of spodumene is 9.04 percent. The only other minerals with such high lithia content are the phosphates, but these occur only in pockets and are not in extensive deposits5/. Actually, however, the lithia content in spodumene is never found to be this high, being nearly always below 7 percent for the pure mineral, and part of the lithia is apparently replaced by other alkalies.

Jan 1, 1937

By Rory Cameron, Chuck Edwards

"Stringent environmental performance criteria and regulations, and the desire to minimize water use have made membrane-based treatment and separation processes an attractive option. This has lead to many advances in all aspects of the technology. Membrane separation processes have found application in sea water desalination, brackish water treatment, decontamination of ground water, and wastewater treatment. Development of membranes with better resistance to harsh feed conditions has created new opportunities for the broader application of membrane separation technologies to mineral processing streams. There are examples in mineral processing operations, including treatment of acidic drainage, pre-concentration of pregnant leaching solution in heap leaching operations, separation of acids and metals from waste streams and intermediate process streams, as well as gold and cyanide recovery from a heap leaching operation. This paper provides a brief overview of membrane technology principles, followed by a discussion of current membrane technology applications relevant to the mining and mineral processing industry. The paper further explores the potential for the application of membrane separation as an integrated component in mineral processing operations.INTRODUCTION Increased regulatory pressures, emphasis on water conservation, and scarcity of water in arid regions have resulted in substantial changes in industrial practices in recent years. As a result, many industries have become more open to adopting innovative technologies such as membrane separation. The mining industry, which is typically very conservative, has adopted membrane separation as an effective end-of-pipe solution for effluent and acidic drainage (AD) treatment; however, its use as an integrated component in plant operations has progressed more slowly. With increasingly stringent environmental regulations coupled with the desire for low- and zero-discharge operations, the use of membrane separation technology for achieving acceptable environmental performance may be unavoidable in the future. The relatively small footprint requirement, versatility, and modular construction of membrane separation units facilitate their introduction into existing processes with a suitable feed stream. Membrane separation is not a stand-alone process that provides the ultimate solution to water and wastewater treatment; however, it can often be economically added to conventional waste treatment plants to increase throughput and/or decrease contaminant output (Mortazavi, 2008). Although membrane separation technology has become an established separation technique that is widely used in drinking water production and other industries, it is still considered an emerging technology within the mining and mineral processing industry. This technology offers many potential benefits such as clean water recovery from wastewater, significant reduction of volume requiring conventional treatment, decreased usage of reagents, and acid recovery, all of which lead to increased treatment efficiencies and lower reagent consumption. This could translate to smaller and more efficient plants with lower capital and operating costs and lower environmental impacts. Plant expansion may be facilitated by incorporating a membrane separation unit operation in order to utilize existing treatment systems at higher throughputs."

Jan 1, 2012

By Claude Cunningham

Ths oonoept of precise. eooursts timing with Elsotronic Delay Detonators (EDD’s) was first ssriously sddresssd in ths mid 80’s end much wss made of the cheapness end profusion of digital wstohes in terms of the likelihood of EDD’s also being cheap and essyto produce. Ten years Iater. with every major explosives group end many elsotronios groups having instituted projects to capitalize on the promise of these devices, production devices are still to come into asneral use.

Jan 1, 1994

By Mel Febesh

Working in New York City has become the graveyard of many Foundation Contractors. Varying subsurface conditions require Foundation Contractors to be aware of the conditions at each particular site and have the knowledge and equipment to successfully complete the project. Looking back, we can see that many of the methods and much of the equipment that were commonly used in the past have been replaced with newer methods and equipment, but sometimes the old methods prove to be the most reliable. This paper will describe examples of varying conditions and construction methods in sites that are close to each other. It will also show different construction problems that are encountered when working adjacent to existing subway structures, when excavating below the foundations of adjacent structures and when ground water is encountered.

Jan 1, 2000

By Don Kay

A two year study into the effects of coal mining induced subsidence on cliff lines was undertaken by the Department of Mineral Resources with the support of a grant under the National Energy Research, Development and Demonstration Program. A new monitoring technique, using an Electronic Distance Meter and acrylic reflectors attached to the cliffs, provided safety for the surveyors and extensive and accurate three dimensional displacement data on the movement of the cliffs as they were being undermined. The study report included many graphs showing the measured vertical and horizontal displacements, differential subsidence, tilts and strains and included analysis of these movements with various parameters, such as, seam thickness, depth of cover and distances between the reflectors, longwall face and the edge of the chain pillar. Some of these graphs are presented in this paper and could be used, with caution, to predict subsidence movements around other cliff lines, after allowing for differences in geology and mining layout. A mechanism is suggested as an explanation for the observed high horizontal movements around the cliff lines. Sixteen percent of the overall lengths of cliffs that were undermined during the monitoring study fell and the contributions of various factors that appeared to influence the cliff falls are discussed. It is concluded that no single factor dominated as the major cause of the cliff falls and, often, many factors combined to cause cliff face instability.

Jan 1, 1992

By Willard L. Hunter

The smelting of tin slags was undertaken at the Bureau of Mines Albany Metallurgy Research Center (AMRC) to produce crude columbium-tantalum ferro-alloy as a unit operation in the production of pure columbium and tantalum oxides or chlorides. Columbium and tantalum-rich alloy was prepared during short unrelated campaigns over a total period of 12 years. Tin slags from Malaya and the Congo (Geomines) were smelted. These slags were reduced by carbon in a small, single-phase, steel-making furnace} a larger three-phase, steelmaking furnace, and a three-phase, submerged-arc furnace, In all cases depleted slags were fluid and easily tapped from the furnace. However, unless diluted by iron additions, the metal product was a viscous, high-melting, heterogeneous mixture that could be removed from the furnace only by hand rabbling.

Jan 1, 1966

By Douglas B. Silver

Traditional cycle theory would postulate that if you have a supply shortage relative to demand, the price will increase because buyers will incrementally increase the price they are willing to pay to ensure that their needs are fulfilled. As prices rise, more supply will be brought on and will eventually exceed demand. This supply excess will cause the price to decline as producers have to lower their prices to sell their goods. What is interesting is that cycles are simply volatility over time. Without the time factor, volatility simply goes up and down. When we add the time element, a cycle is created. This cycle can be big or small. In mining?s case, we are talking about a Super Cycle ? a big cycle. But a Su-per Cycle can be formed in two ways. It can form by either increasing the wavelength or the volatility. If these two elements are combined, a Super Cycle is formed. It is bigger than the normal cycle in terms of time duration and extent of volatility. A recent study (Fig. 1) conducted by Cuddington and Jarrett showed an interesting proof of Super Cycles and suggests that these cycles last between 15 and 30 years. So, what causes a Su-per Cycle? Is it a convergence of unrelated events or a consequence of related events? In a global community everything is related. Equilibrium theory would also take the position that a Super Cycle is a consequence of events.

Jan 1, 2008

By S. Dessureault, Z. Gavelan

As globalization continues, sustainability and social responsibility has become essential in foreign mining investment. However this global trend and the increasing acceptability toward the globalization process, viability and sustainability are not always achieved. Viability and sustainability of mineral projects is dependant on the social and political environment of the region where the mining venture is located and is based on the interaction between the mining entrepreneurs, national-local government representatives, communities, grass-roots groups and independent civil organizations. These are the organizations, which play the acting roles on the viability of mining projects and are the main source of socio-political risks for the project. Throughout the decision-making process to invest in a mineral project, socio-political risks are quantified using a set of measurable variables. Nevertheless, these risk measures should be dependent on specific industries. Two mineral projects, even in the same mining district, may have significantly different political risk profiles based on their own socio-political variables. This paper describes a methodology that takes into account local social and political variables in defining a project-specific’s political risk profile. This contrasts with more typical political risk measures that focus on the country’s overall risk profile. Mining operations must operate on a local scale necessitating the development measure that considers more local variables.

Jan 1, 2004

By G. L. Oldright

This paper is the fourth of a series of preliminary papers on smelting in the lead blast furnace.4 The objects of this investigation are to determine the conditions obtaining within the blast furnace by direct experimentation and to correlate these conditions with operating factors, furnace behavior, and metallurgical losses. ACKNOWLEDGMENTS The authors wish to express their appreciation to the management of the International Smelting Co. at Tooele, Utah, for their whole-hearted cooperation in this investigation.

Jan 1, 1929

"As mine head grades decline and orebodies become more complex, traditional mineral processing techniques and flowsheets to achieve saleable concentrate become more difficult to design and construct. Mines with lower quality concentrates or concentrates with penalty elements are particular under threat. The economics of these operations are far more susceptible to metal price, concentrate treatment terms and the availability of other, cleaner concentrates. Additional value may be realised for these orebodies through improved recovery by producing a low grade middling concentrate for further processing, in conjunction with a saleable concentrate.The most cost effective way to reduce impurity levels is to do so as early as possible in the mining value chain. Technologies such as fine grinding and fine particle flotation are well established as effective methods for impurity rejection in mineral processing. What is normally overlooked is how a hydrometallurgical process could also be integrated in the overall flowsheet to achieve higher overall recovery at the mill. In the base metals environment, this is mainly because hydrometallurgical processes are associated with production of metal or use of expensive and toxic precipitating agents once the minerals of interest are solubilised. These processes can be very expensive, particularly with rising power costs and poor economies of scale in capital costs associated with low production rates from middling streams.Glencore Technology (GT) has recent experience in the treatment of middling and low grade concentrate streams as well as tailings streams to compliment a concentrator flowsheet in a refractory gold and base metals setting. The value proposition is the isolation of a low grade middlings concentrate from the primary circuit or the tailings stream for upgrading to an intermediate product with an equal or higher grade than the primary concentrate to allow blending for sale. This allows plants to operate on a more favourable part grade-recovery curve while avoiding the expense of metal production. For existing operations this is particularly attractive since it can be added on with no process interruptions.Two case studies are examined showing flowsheets and costings to arrive at the value proposition of the GT low grade treatment flowsheet."

Jan 1, 2017

By S. Narasimha Rao

Significant amounts of lateral load may act on pile foundations supporting structures such as transmission line towers, tall structures, bridge abutments, offshore platforms, quay wails, harbour structures and anchorages for water front structures. There were several theoretical and experimental studies conducted on laterally loaded piles in clays to determine ultimate lateral capacity and deflections under working loads. Under a lateral load, a pile deflects in the direction of load application and the soil in front of the pile offers resistance to this movement. The ultimate lateral resistance of a pile can be estimated considering the statics of the pile for a known distribution of soil resistance with depth. In this paper, considering the contributions from both lateral shear drag and frontal passive earth pressure, a method has been proposed to estimate the ultimate lateral capacity of rigid piles in clays. The lateral shear drag has been estimated in terms of adhesion and shape factor. A few load tests were conducted on model piles subjected to lateral loading and these experimental values are used in verifying the proposed method. The reported results obtained from both model tests and field tests were used in support of the predictions made. In all the cases, there is a good agreement between the predicted and measured capacities.

Jan 1, 1996

By P. J. Closmann

Steam zone growth as a function of time has been calculated for the case of constant rate steam injection into a preheated reservoir. To simplify the calculation a linear temperature profile has been assumed in the cap and base rock at the start of steam injection. The results indicate that at early times augmentation of steam zone growth due to preheating should be greatest. At longer times the steam zone development becomes close to that calculated with no preheating. INTRODUCTION With the increasing application of thermal recovery processes to recover viscous oil, cyclic steam injection has become important in many large-scale projects. In this process, the cycle of steam injection followed by oil production is repeated a number of times. At the beginning of the second and later cycles, steam is injected into a reservoir that has already been heated but that has lost part of its heat both in produced fluids and by conductive heat loss away from the injection zone. In such a case, the temperature level of the injection zone and the temperature distribution of the surrounding rock will affect the growth of the steam zone developed during the subsequent steam injection. Knowledge of the size of steam zone developed is important in determining the amount of oil displaced and the extent of heating in the reservoir. It is also useful to be able to compute the size of the steam zone for cases where thief zones take most of the injected steam. This paper presents a fairly straightforward method of estimating the steam zone developed in a preheated formation, based on certain simplifying assumptions. Some cases of steam injection into a reservoir at its original temperature have already been considered elsewhere.1-3 Because it is difficult or impossible to obtain an accurate representation of the temperature distribution in the reservoir some time after initial heating has taken place, in this work, a linear temperature profile in the cap and base rock is assumed (Figs. 1A and 1B). The linear profile has the advantage of yielding heat flow equations that

Jan 1, 1969