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By M. Felsenthal

Engineers are frequently faced with the problem of having to predict oil recovery from a solution gas drive reservoir in the early life of a field. This is often the time when actual laboratory or field-derived gas-oil permeability (kg/k0) data are not yet available. Although excellent collections of k0/k0 data for various types of rocks may be found in the literature,1,2,3 a need exists for a more detailed correlation of k0/k0 data with core properties such as porosity, permeability, clay content or pore-size distribution. It is the purpose of this article to present this type of correlation for sandstone material. The correlation is based on laboratory tests performed on over 300 core samples from 19 reservoirs in the United States and Canada. EXPERIMENTAL Cores were analyzed by routine procedures, using samples of conventional size (7/8-in. diameter, 7/8-in long) cut parallel to the bedding planes. Air permeability was measured at 1.67 atm mean pressure in a Hassler-type apparatus. Porosity was determined with the aid of a Ruska bulk volume meter and a Boyle's Law rock volume meter, An evaporation method' was used to evaluate irreducible water saturations. Core samples were saturated with 25,000 ppm NaCl brine. The brine was reduced to the irreducible saturation, and the remainder of the pore space was filled with kerosene. This was followed by multiphase flow tests using the so-called "dispersed feed" technique.5 n this technique, gas and oil (kerosene and kerosene-saturated air) were dispersed with the aid of a porous Alun-durn feed head, the face of which contained a waffle-shaped system of Lucite-lined grooves. Oil entered the back side of the feed head and emerged at the raised areas of the front face. Gas was introduced directly into the system of grooves at the front face. The gas-oil mixture then entered the test core which was kept in capillary contact with the feed head. Permeabilities were determined from rate and pressure measurements and saturations from weights. All determinations were performed at equilibrium or steady-state conditions. Pore-size distributions were determined on selected samples by a mercury injection technique.6 GENERAL CORRELATIVE TRENDS When examining data from a given reservoir, it was noted that k0/k0 vs saturation curves became generally less steep as specific air permeability increased, a development that has a favorable effect on oil displacement efficiency by solution gas drive. This trend has also been reported by others in the literature.' An effect of porosity on k0/k0 data was also noted. This effect was not generally discernible in a study of relative permeability data for a given reservoir but became apparent when data for sandstone reservoirs of similar lithology but differing average porosity were compared. For instance, in a comparison of argillaceous and/or calcareous sandstones from 11 reservoirs ranging in average porosities from 14 to 28 per cent, a definite trend was noted, indicating that for a given permeability k0/k0 curves became less favorable (i.e., steeper) as porosity increased. A similar trend was observed for a group of comparatively clean sandstones from five reservoirs ranging in average porosities from 15 to 21 per cent. For a given permeability and porosity, comparatively clean sandstones gave more favorable k0/k0 curves than argillaceous and/or calcareous sandstone or chert reservoirs. The laboratory studies also showed that least favorable k0/k0 curves were exhibited by shaly sandstone, conglomerate, and sandstone containing carbon inclusions. Table 1 lists the various source reservoirs classified by lithology types. To facilitate a correlation of k0/k0 data with core characteristcis, it was found expedient to work with

By Turcotte. Yves-Laurent

Notre conférencier, Monsieur Yves L. Turcotte, Vice-président et Directeur général chez Promaintech Novaxa est diplômé en génie industriel de l?Université du Québec à Trois-Rivières et détient une maîtrise en gestion de projets de l?Université du Québec à Montréal. Il est une véritable sommité canadienne dans le domaine de l?amélioration de la performance des organisations. Provenant d'entreprises manufacturières et de services, il possède plus de 20 ans d?expérience en tant que développeur de technologies, conseiller et formateur auprès d?entreprises. Il a à son actif la réalisation de mandats dans plus de 400 entreprises. Il est reconnu pour sa grande capacité d?analyse et pour trouver des solutions novatrices et profitables aux problèmes des organisations les plus complexes. Aujourd'hui, il dirige Promaintech Novaxa, une division de DMR, qui a célébré son dixième anniversaire en 2006. Cette organisation ayant des places d?affaires dans la région de Montréal, Québec et Vancouver compte plus de 50 professionnels et a une carte de visite dans 16 pays. Les axes d?intervention sont le Management, la Productivité, la Fiabilité, l?Innovation et l?Amélioration Continue.

Feb 1, 2008

By Meghan M. Murphy, Derek Penrice

The Downtown Rail Extension (DTX) is principal element of the planned second phase of the Transbay Joint Powers Authority’s (TJPA) Transbay Program. When complete, this regionally critical project will connect Caltrain’s regional rail system and the California High-Speed Rail Authority’s statewide system to the Salesforce Transit Center in downtown San Francisco via a 1.3-mile tunnel. Studied since the 1970s, the DTX has now received environmental clearance, and key stakeholders are aligned on the project’s configuration and its expedited delivery. This paper describes efforts to optimize the DTX configuration and develop an informed project delivery strategy that incorporates construction industry feedback on project phasing, contract packaging, and procurement methods that accomplish the project’s budget goals.

Jun 13, 2021

By Morgan Walker

Intermittent injection of gas in gas-lift pumping is a variation of the common practice in that the gas is delivered to the well for a short period, called the "on time," followed by a period during which none is admitted, called the "off time," instead of being admitted continuously at a constant rate or by intermittent flowing in which it is occasionally delivered to the well in just sufficient quantity to flow off the accumulated head of fluid. The term "gas" is used throughout this discussion but it should be remembered that in so far as the operation is concerned either air or natural gas may be used. The equipment at the well is the same as commonly used in gas-lift installations and gas may be admitted to either the tubing or the casing. It seldom occurs that all the wells on a lease can be pumped economically by intermittent injection from one header. Wells that have flow characteristics which permit their being handled together have their intake lines grouped at a central compressor station. Well groups may consist of two or more wells. The total volume of gas delivered by each group of compressors goes to one well at a time through a quick opening valve, each well connected to the header receiving its charge of gas in turn. Special cases may require a deviation from this arrangement. The distribution of the gas to the different wells is effected by an automatic timing device which operates quick-opening valves on the intake lines. The timing mechanism may be actuated by electricity, liquid or gas pressure, The essential factor in the operation of the timing mechanism is that as one intake valve is closed another must be opened. Water-operated Timing Device Timing devices operate the intake valves either directly, or indirectly by pilot valves. Of the former type one that is operated by water and has given satisfactory service is shown in Fig. 1 and can be made on the lease. The horizontal cylinder is a piece of 10-in. casing about 7 ft. long, closed at each end and free to oscillate about a fulcrum at the center.

Jan 1, 1929

By A. Noël, R. Lapierre, M. Provencher

"Modem aluminum smelters are facing significant operating cost pressure. Key methods used by smelters to manage this pressure are automation and production-information systems to optimize processes, manage quality, anticipate problems and reduce operating costs. In 2002, Aluminerie Alouette Inc. began its Phase II Expansion project, and retained the joint venture of SNC-Lavalin and Hatch (SLH) as its engineering, procurement and construction management (EPCM) team. Alouette had the distinction of being one of the most efficient aluminum smelters in the world. Alouette already understood the importance of systems integration in project delivery. For Phase II, key objectives were identified to ensure ""a state of the art"" integrated architecture that would support Alouette's production goals to integrate the existing facilities with the expansion, to form a single efficient facility and meet project schedule and budget targets. Achieving those objectives within the context of a large project often creates major challenges due to the nature of the traditional EPCM delivery model, which relies on several vendors and third-party-systems integrators. In this case, an integrated Alouette-SLH team was made responsible for all aspects of the systems integration, taking over the task from most suppliers. The integrated team was responsible for delivering an automation system and plant-wide-production IT system for the new facilities while accommodating migration for the existing systems. Through the use of rigorous methodology and advanced state of the art technology, the IT and automation strategy led to significant value creation and is recognized today as one of the key factors of the project's success. The primary results were: fast and efficient start-up of facilities, due to quality programming and implementation; a plant able to operate as a single entity; automation and IT systems delivered before time and under budget; standard programming methods implemented throughout the plant; and reduced and simplified maintenance."

Jan 1, 2006

By George K. Burke

Jet grouting was first introduced into North America in the late 1970's, soon after the conception of the system in Japan. However, it was not until the mid-1980's that the technique began to gain acceptance through the renewed interest and efforts of specialist U.S. geotechnical contractors. Since this time, innovations by both American users and other users worldwide have further advanced the technology, with a corresponding increase in the range of practical applications. This paper discusses the evolution of jet grouting in North America, from simple single-fluid methods to more complex triple-fluid methods, to the energy-intensive double-fluid and SuperJet methods. Case histories, illustrating a variety of jet grouting methods and applications, are cited to support the newest United States applications.

Jan 1, 2002

By P R. L Browne

Study of geothermal systems in the Taupo Volcanic Zone (TVZ) has significantly advanced our understanding of the processes of epithermal mineralisation. The three main lessons learnt are: 1. knowledge of their chemical anatomy; 2. precious metal transport and deposition; and 3. hydrothermal alteration zoning. These are described in the context of ore formation and exploration.

Jan 1, 1997

By E. B. Kester

A study of the composition of the corresponding fractions of a primary and a high- temperature tar was undertaken to throw light on the net results of the pyrolysis of the primary products of coal decomposition in high-temperature coking practice, with reference both to total quantities of the chemically similar constituents and to their distribution throughout the boiling range. No exactly parallel investigations are on record. The distribution of substances in high-temperature tars, however, is fairly well understood. Such tars are more or less similar, for they consist of the more stable phenols, aromatic and olefinic compounds resulting from the pyrolytic decomposition of a wide variety of primary tar constituents. For example, from a typical distillation curve for high-temperature tar phenols4 it may be seen that the greatest portion of the phenols distills between 180° and 220° C., a fairly narrow range.

Jan 1, 1932

By Siqing Liu

A low-grade cassiterite-magnetite ore from Sichuan province, China, is finely disseminated, assaying 0.39% Sn and 23.20% Fe, respectively. Mineralogy studies show that the fine-sized cassiterite is mainly disseminated in iron minerals and gangue. Moreover, the embedded size of cassiterite is very fine and must be ground to -0.01 mm to achieve a degree of liberation of about 90%. Therefore, fine grinding needs to be conducted to get a high quality tin concentrate and a great loss of tin cannot be avoided when treating the ore by gravity concentration. Based on the above facts, a two-stage separation, with a low intensity magnetic separator and a shaking table, was selected to test the ore. Compared with other similar plants, a relatively good separation has been achieved. Three acceptable products for smelters were obtained as following: iron concentrate assaying 61.69% Fe with a recovery of 75.09%, tin concentrate assaying 27.21% Sn with a recovery of 56.97% and a sulfur concentrate assaying 40.86% S with a recovery of 32.03%, respectively.

Jan 1, 2011

By G. J. Joy

Although rates of pneumoconiosis in coal miners have declined substantially in the United States since the passage of the Federal Coal Mine Health and Safety Act of 1969, new cases continue to occur, including cases of rapidly progressive disease. In contrast, Australia's underground coal mining industry has reported few new cases of pneumoconiosis for more than 20 years. Mortality from coal workers' pneumoconiosis in official health statistics and the prevalence of pneumoconiosis among miners screened in X-ray surveillance programs are also lower in Australia. The U.S. National Institute for Occupational Safety and Health (NIOSH) was requested by both industry and labor stakeholders to examine this issue, with the ultimate aim of reducing the rate of pneumoconiosis among U.S. coal miners. A number of factors, including coal dust exposure, silica exposure and coal rank were examined as potential contributors to the above noted differences. Comparison of coal rank data from each country did not illuminate the issue. Air sample data from the coal mining industries in both countries show that coal dust levels in Australian mines are somewhat higher than those reported in similar U.S. mines; however, quartz exposure for Australian miners is lower than for many U.S. miners. If quartz is contributing to the greater number of cases of pneumoconiosis in the United States, more effective dust control measures, as well as an independent exposure standard for respirable quartz in coal mining, should be implemented to reduce this potentially disabling condition.

Jan 1, 2012

By G. Adderley, A. Wetherelt

The problems of poor drilling in underground operations have been highlighted on many occasions. Incorrect collaring and poor angular deviation can all lead to an increased block size, dilution, over-break adding to both cost and time, while in a tunnelling operation sidewall damage and a poor percentage pull from a blasted round has similar consequences. This paper sets out to further investigate the ability of the laser scanner method of obtaining drill hole deviations and collaring errors at the face as described by Wetherelt and Williams (2006). Tests were carried out to compare measured inter-hole burdens from this method in comparison to that obtained using a total station survey. To investigate the ability of these methods to accurately determine drilling errors, a field test was carried out through an analysis of a series of pre-drilled blast holes of known inclination and direction. A time-motion study was also conducted for a varied number of holes to assess the usability of each method. In line with current research into blast vibration being undertaken at the Camborne School of Mines, 6 cut blasts were carried out to establish the effect of poor drilling on a blasts success to see whether an increased burden at the toe of a hole had an influence on vibration.

Jan 1, 2009

By Francisco Sena Leite, Pedro Brito, Gean Frank, PhD Soeiro de Carvalho, Jose, Vinicius Miranda

The consequences of rock blasting with explosives are directly related to the accuracy of drilling and, because they have an effect on fragmentation and ground level, they should be controlled to ensure a problem free production, increase work safety and reduce environment impact. Safety control is one of the most important processes in detonation, since it can compromise the worker security on site and, eventually, neighboring communities. Due to the technology advancements, it is possible to build a hole deviation control device with “of the shelf” parts, and for that reason the authors decided to evaluate the possibility of measuring hole deviation by creating a portable prototype using an electronic sensor capable of measuring the acceleration on objects, that is, to measure the own acceleration of a system, known as "accelerometer" and a micro-controller to handle and treat data. The main idea behind this paper is to validate the power of the Euler method, given the stepping limitations of the sensor and micro controller in order to reproduce of the hole shape. A case study was carried out, comparing the measurements of borehole deviations made by a traditional equipment and the prototype. A mobile application was also created in order to recover and treat and display the data to the user. For validation of the prototype, several holes were measured using the two devices. A residue analysis was used to validate the data obtained. After analyzing and confirming the effectiveness of the new equipment, the normality tests prove a symmetric distribution with null expected residual mean and minimum variance. Consequently, the accuracy of the prototype is evidenced. Thus, the authors aspire to emphasize the potential of using these sensors allied to a traditional numerical method for analysis of hole deviation.

Jan 1, 2019

By William Petruk

Image analysis studies were performed on mill products from pilot-plant and laboratory tests that had been conducted to determine the effect of grinding media on the selective flotation of two zinc-lead-copper ores. It was found that, when the ores had been ground to the same degree of fineness with flint pebbles, ceramic pebbles or ore fragments (autogenous grinding) as with steel balls, there generally was increased sphalerite, chalcopyrite and galena liberation in the flotation feeds, depending on the textures of the minerals. The increased sphalerite liberation fully accounted for the improved zinc recoveries that were obtained when steel balls were replaced by either pebbles or ore fragments. The increased chalcopyrite and galena liberation accounted for part of the changed technical efficiency of concentration, but other factors, probably changes in oxidation and reduction of iron and in consumption of oxygen, also contributed.

Jan 1, 1977

By Zachary Q. Maassen

The purpose of this paper is to highlight the environmental benefits of properly managing slurry waste as it is generated on site. The following projects will be used to illustrate the importance of proper onsite waste management. Project: Jet Grout Backflow Dewatering The goal was to dewater the backflow directly onsite to produce a dry, solid waste and reusable water. The backflow spoil was pumped directly to the dewatering system as it was generated. Utilizing mechanical separation equipment and flocculation polymer the waste volume was reduced by 44%. Due to the site footprint and high volumes, slurry waste removal and onsite processing were the only two feasible options. Onsite dewatering proved to be the environmentally beneficial option as it eliminated the need for slurry waste hauling and disposal. The benefits of utilizing a dewatering system are listed below: Project: Soil Mixing Spoil Recycling for Slurry Wall Construction In this application the spoils generated contain bentonite mud, cement mixture and organic ground soils. The goal of this project was to process the backflow mixture to recover reusable bentonite mud and separate the soil as a dry, stackable waste product. The treatment system replaced the traditional method of vacuum truck extraction and facility disposal. The environmental benefits of properly handling the backflow is a decrease in fresh water usage, bentonite additive reduction, and the reduction of CO2 emissions. The paper will consist of a project scope, technical equipment and process description, environmental impact reduction calculations and lessons learned for each project.

Jan 1, 2018

By L. Barry Phelps

The application of an open-pit Materials Handling Simulator (OPMHS) to analyze mine planning and scheduling problems in large surface mines is discussed. The mine chosen for this application employed a large stripping dragline working in tandem with a shovel-truck haulback system for removing overburden. Large bottom-dump trucks were employed behind a coal loading shovel to transport the exposed coal out of the pit. Specifically, the current operations and the recommendations for short term and long term improvements were simulated on OPMHS. The effects of changing the operating parameters of the equipment on the total system were evaluated. Several alternatives were also studied for the best use of the existing equipment if the current operating parameters could not be improved upon. The results of the application are discussed.

Jan 1, 1978

By Michael S. Kucker, Stuart Warren, Robert A. Robinson, Michael J. Lehnen, David McAllister

Geotechnical conditions exposed by the phased exploration programs have had a major impact on the selection of excavation and support methods, dewatering requirements, size of openings, vertical alignment, and estimated cost of construction for the Beacon Hill Tunnel and Station section of the “Link” Light Rail. Beacon Hill is comprised of a very complex glacial geology, including numerous slickensided fractures, injected sand dikes, and multiple perched groundwater levels as revealed by a phased boring program and exposed in a test shaft. The Geotechnical Baseline Report (GBR) presents this complex geology along with a “tool box” of alternative additional support systems to accommodate the varying ground conditions during construction of the station excavation. Additional explorations will also be accomplished during construction to further refine the geotechnical interpretations and provide an opportunity to use pro-active ground improvement techniques to optimize the station excavation and support requirements.

Jan 1, 2005

By Karsten Zimmermann

Surface deformation monitoring is required all over the mining industry. For example oil and gas companies need this information to support exploration and production activities and to detect impacts from surface subsidence of existing hydrocarbon fields. Also opencast mines require large area information of subsidence due to dewatering of the overburden. Because of this, a lot of surface deformations measurements with GPS or traditional geodetic measurement techniques have been conduced during the last decades. This paper presents the actual capabilities to analyze GPS data using the state of the art Bernese GPS Software for GPS post processing. A new way of monitoring subsidence is a combination of GPS and satellite InSAR data. Considering this it is hoped that a combined strategy will permit receiving overall more information by integrating high point density of InSAR and accuracy of GPS. DMT is one of the leading actors on GPS services especially for monitoring surface movements from underground activities e.g. mining, water pumping or oil and gas exploitation. The paper will discuss preferences and problems of this approach on results of a current project of DMT.

Jan 1, 2008

By S S. Kanchibotla, I Brunton

Most blast fragmentation models assume the rock mass properties, explosive properties and blast design variables to be constants and uniformly distributed within a blast. However, in reality all these input variables vary within a blast resulting in variation in the resulting fragmentation size distribution. A stochastic modelling approach is introduced in this paper to quantify this variation. This technique takes the input variables as statistical distributions rather than constants and through several thousand iterations, generates a statistical representation of the expected fragmentation resulting from a production blast. A case study of three production blasts from a large open pit mine are presented and the modelled fragmentation æenvelopeÆ shows good agreement with the fragmentation æenvelopeÆ estimated from Split image analysis. The various blast-related parameters influence different parts of the fragmentation distribution, eg rock strength and explosive velocity of detonation have most impact on the fines. The technique is used to identify the parameters that have the greatest influence on various size fractions. Such an analysis will be useful to direct resources to efficiently minimise the variation.

Jan 1, 2001

By K. T. Stafford, N. A. Iverson, V. T. McLemore

Southwestern New Mexico is part of a large belt of Late Cretaceous to Eocene copper porphyry deposits found in Arizona, New Mexico, and Mexico. These deposits are the result of arc magmatism that occurred during the Laramide orogeny. Recently, attention has been brought to other commodities that can be extracted as by- and co-products, many of which are critical minerals. A new compilation of the geochronology of these deposits shows two main pulses of magmatism that produced mineralized deposits and, along with new dates by the author, shines new light on the geologic history of these deposits and the role it plays in critical mineral abundance.

Feb 1, 2024

By Jon K. Ahlness

The Bureau of Mines investigated technologies for testing the integrity of in situ leach mining wells, as required by environmental regulations. To test for leaks, inflatable packers were used to seal the well casing. Laboratory testing determined that the packers could contain a casing pressure up to 50 to 60 psi (345 to 414 kPa) less than the packer inflation pressure. Single-and double-packer configurations were successfully field-tested in 32 wells ranging from 500 to 530 ft (153 to 162 m) in depth. A rigid pipeline and a hoist truck were used to run the packers in and out of the wells for the double-packer tests, which averaged 2-1/4 h each. In an effort to decrease the time of the rigid-pipe double-packer test. a self-contained trailer-mounted test system was designed and built. It utilizes a winch and steel cable to run the packers in and out of the well and high-pressure nylon tubing for packer inflation. This system was successfully field-tested in eight wells averaging 650 ft (198 m) in depth and resulted in a time savings of 13 pct and an operator-hour reduction of 42 pct.

Jan 1, 1985