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By J. H. Faulk

An examination is made of the various factors influencing drilling rate and drill bit life in various diameter holes. It is concluded that drill bits in the size range 4% to 6 1/4 in. can be used to attain substantially the some daily drilling progress as conventional size bits in soft rock drilling operations. An examination of the most important factors influencing "hazard of losing the hole" in the different hole size results in the conclusion that the smaller hole sizes can probably be drilled at reasonably low risk. However, this risk will be somewhat greater in the smaller diameter holes, requiring that special drilling and mud engineering practices be used to make small diameter holes practicable in soft rock drilling operations. An engineering analysia is made of the power and hydraulic requirements of several drill string-hole combinations to test the feasibility of drilling .small diameter holes in soft rock areas. Large econormies in rig power requirements appear possible by drilling .smaller .size holes in these operations. INTRODUCTION The industry now is re-examining the utility of small diameter holes in the light of substantial technical advances made in recent years. Faced with increasing cost of finding reserves and with proration after developing them, the industry must either develop methods of economizing or receive a lower rate of return on investments. Small diameter holes appear to involve an attractive method of economizing. Our objective is to determine if this is technically possible in soft rock operations. Soft rock, as used in this report, refers to those formations of a "drill-ability" corresponding to that of all Gulf Coast formations shallower than and frequently including much of the Eocene rock system. An important phase of technology which we shall examine is relative drilling rate and bit footage which may be obtained with various size bits. Rig operating efficiency, particularly as influenced by hazard, is also discussed in detail. The technical conclusions resulting from these examinations are used to develop sample drill string design and rig horsepower requirements for drilling holes as smaH as 4 3/4 in. and larger. The principal criterion used for the drill string design is that approximately the same daily drilling progress would be possible in all size holes in soft rock operations. This facilitates a comparison of rig size required for drilling the hole sizes in the range between 4 3/4 and 8 3/4 in. BROAD PROBLEM OF DRILLING RATE AND BIT FOOTAGE The three factors controlling daily drilling progress are: (1) drilling rate of bit while on bottom turning, (2) bit footage, and (3) rig operating efficiency. Let us look now at the first two of these factors. Drilling technology has progressed to the point that a semi-quantitative analysis of the effect of various operating variables upon these factors can be made. Those factors which apparently limit both drilling rate and bit footage for bits now in use are: (1) bit design, (2) weight on bit, (3) hydraulic cleaning capacity for bit cutting surfaces and hole bottom, and (4) rotary speed. (We neglect the effect of mud and formation properties because these factors arc the same for the various size bits.

Jan 1, 1957

By Feng Yongxuan

Anchored sheep pile is normally used in deep excavations, many of which only require stability in accordance with Terzaghi theory. In this paper, based on the experience, new lateral earth pressure method is adopted taking account into interaction among soil, anchors and sheet piles so that a group for the project under very difficult conditions and very severe requirments, especially, for the displacements are determined according to that mentioned above. During and after construction, displacements monitoring were carried out for about four months, which was proved that there was a little difference between calculation and practice.

Jan 1, 1991

By M. T. Abasov

The work suggests an approach to the problem of optimally planning the drilling and development of gas fields. The approach is based on systems analysis and allows a joint optimal choice of the total number of wells in the field, their spacing in the reservoir, the diameter of production tubing, drilling dynamics, the number and spacing of drilling platforms and well pattern schemes for each plat- form as well. The optimal solution satisfies the set of technical- economical requirements and provides a minimum value of discounted total expenditures (capital costs plus operating costs). A mathematical model of the problem is presented. This work represents an extension of the authors&apos; previous investigations that formulated and solved problems of optimal drilling of oil and gas deposits by directional wells [1] and problems of optimal control of the number of active wells in multi-reservoir oil and gas fields [2], [3]. For construction of the mathematical model we choose a range (Nmin, Nmax) of possible values of the total number of wells, N, which should be drilled in the deposit. Here Nmin, Nmax are minimum and maximum numbers of wells correspondingly, that should be drilled into the reservoir. N[€](Nmin = N1, ... N[o], ..., Nm = Nmax). For simplicity a one-reservoir gas field is considered. It is assumed that: (a) wells are spaced in the reservoir uniformly, (b) there is a certain algorithm providing a uniform spacing of the given number N[o] ([0]=l, . . . , m) of wells in the reservoir, (c) the diameters of the production tubing for all the wells are the same. The relation Qz (x), i.e. the dependence of the cumulative output of gas from the cumulative "well-years" of operations is constructed for each diameter dZ from the given range of diameters d1< ...< dr.

Jan 1, 1977

By G. B. Harris, A. R. Laplante

Fine tungsten was used to mimic gold and fine and coarse silica and magnetite to mimic gangue. The optimum flow rate of fluidisation water varied from 1.7 l/min for fine silica to 5.6 l/min for coarse magnetite. Overloading at optimum flow rate was then investigated. With fine silica gangue no overload occurred under any of the conditions studied, and there was very little overload with fine magnetite. Coarse silica caused appreciable overload, but only after a significant bed of tungsten had been formed; with fine magnetite gangue the onset of overloading occurred earlier. Finally, with coarse magnetite severe overloading occurred almost immediately. Overloading was modelled using a first-order kinetic rate constant for erosion of the concentrate bed and a critical mass of constant above which it takes place. The results clearly demonstrate the importance of removing oversize to maximise recovery, particularly with a high-density gangue

Jun 18, 1905

By C. P. Parsons

During the past year considerable interest has been shown in cementing operations for shutting off bottom water, whipstocking, etc. A number of plug-back methods have been used, with various adaptations for special conditions, but those described in this paper are representative of the methods now in use. Conditioning the Well Various preliminary operations for improving the results from plug-back operations have been evolved. In one method, a nitroglycerin shot is discharged at the upper portion of the formation to be plugged off, the purpose being to make a wide place in the hole in order to give the cement a more secure anchor against thrust pressure of the water against the bottom of the cement plug after the well is again put on production. Another is intended to attain a similar result by under-reaming a wide place in the hole by means of a rotary wall scraper. In one well in which this device was used there was a water sand at the bottom of the well immediately below the cap rock above which the oil sand occurred. Before the plugging back operation, the water sand was underreamed in an attempt to get a square shoulder on the underside of the cap rock, in order to prevent the water from breaking in over the top of the cement plug after the well should be put on production, and also to get a more secure anchor for the cement plug against the thrust pressure of the water against it. As an aid in calculating the amount of cement required to fill a given amount of hole to be plugged back, a device has been developed for measuring and recording the irregularities and cavities in open holes, called an "open-hole recording caliper." If consists of a steel shell, 5 in. in diameter, which encloses a recording mechanism that receives impressions from four movable arms that make sliding contact with the wall of the hole. The arms operate a ratchet, which raises and lowers a recording stylus against a chart. Each arm registers its own radius. The device is run into a well on a steel measuring line. While the device is being lowered, the arms are folded inside the shell; they are

Jan 1, 1936

By T. R. Ellis

The vast majority of valuations produced for mineral properties using the net present value method provide an estimate of investment value or use value. Such an estimate can be a long way from the price that the property would actually sell for if placed on the market. Indicators from the market need to be used to validate or modify the net present value calculation if market value is being appraised. The comparable sales and replacement cost methods used in the appraisal of urban buildings generally fail when used in the appraisal of mineral properties. Other methods of sales analysis are introduced. Guidelines for what a minerals appraisal report should contain are presented.

Jan 1, 2002

By Daniel H. McClain

A unique partnership between the Colorado Mine Safety and Training Program (CMSTP), the Colorado Rock Products Association (CRPA) and the Higher Education and Advanced Technology (HEAT)Center resulted in a video CD-ROM training program for new miners entering the aggregate industry. Cooperation from everyone involved, including the U.S. Mine Safety and Health Administration (MSHA),made this the product against which other training materials in the mining industry will be measured in the 21stcentury. This product’s versatility and wide application make it a tool that is as critical to a mine’s success as any earthmoving machine. The state and federal grant money involved allows this product to be affordable to small operators and independent contractors. The quality of this two CD-ROM set rivals any commercially made CD-ROM training.

Jan 1, 2003

To provide a flexible, low-maintenance, low-cost continuous mine air monitoring system as an alternative to conventional fixed-point, electronic monitoring systems. Background Continuous monitoring of mine air is highly desirable (and often required) not only to improve miner safety, but also to increase mine productivity. Continuous air monitoring systems can provide earl" warning of developing fires, excessive methane accumulation, reduced oxygen levels, and other developing problems in remote, inaccessible or sealed areas, and in active workings. Fixed-point, electronic systems require one Sensor for every gas to be measured at every defined monitoring location. As the number of monitoring locations increases, so does the cost, along with increases in the time required for routine maintenance and calibration of the sensor System cost also increases when monitoring locations are identified for mine areas requiring permissible electrical equipment.

Jan 1, 1988

By A. R. Przybylek

A fluid bed dryer has been designed for a nonconventional application to upgrade the value of fine anthracite culm and silt recovered from culm banks and anthracite tailings pond beds. This material can be seen as large spoil piles scattered throughout the anthracite coal regions of Eastern Pennsylvania. Engineering of the system commenced in December of 1986 and at this writing start-up is scheduled for late October or early November of 1987. This paper will focus on generalities concerned With system design and operation, and qualify the differences from conventional fluid bed coal drying systems.

Jan 1, 1988

By S. C. Tadolini

Roof support systems have evolved from standing posts and timbers to a generation termed ?big nails? where steel bars are inserted into boreholes and anchored with expansion shells and/or resin cartridges. These systems have been effective but are limited to mining height. Additionally, the properties of steel do not resists shear forces or have the flexibility being required in difficult ground conditions. The next generation of roof support systems is coupling the best parts of the ?big nail? and resin grouted cable bolt systems. This paper will present the advanced technical solutions of the next generation of cable systems that includes an indented high-capacity PC-strand used with a variety of fixtures. Case histories of support applications will be presented.

Jan 1, 2012

By R. S. Sandhu, L. E. Baker, W. Y. Shieh

The finite element method of analysis was introduced by Clough.1 Within a short period, it has developed into a powerful solution technique in structural and continuum mechanics. It has been used to solve boundary value problems in two and three-dimensional elasticity.2-5 Anisotropy and heterogeneity of materials were allowed for at the earliest stages. 1,4 Its application has been extended to allow for cracks,5 creep and viscoelasticity, 6,7 incremental construction,6-8 nonlinear elasticity3,9 effect of joints in rock,10 and to materials with different behavior in tension and compression.7 Because of its versatility, the finite element method has found increasing application in the field of rock mechanics. In fact, several of the more significant developments have been motivated by problems in this field. Elasto-plastic material behavior based on the incremental or rate-type theory of plasticity rather than the deformation theory was considered by Reyes and Deere11 A material law based on a generalization 12 of the Mohr-Coulomb criterion was used. In this chapter, the formulation of material laws developed by Reyes and Deere 11 is used. An efficient analysis procedure, incorporating recent developments in finite element analysis, is developed for plane-strain conditions. To demonstrate its effectiveness, the procedure is applied to three cases, one for which an exact solution is available, another for which field observations had been made, and a third one for which a parallel study was made, using an accepted limit-equilibrium method.

Jan 1, 1970

By F. J. Arriagada

A conventional technique used to process auriferous sulfidic concentrates involves a pre-leach oxidative-roast step. The structural characteristics of the calcine have a strong influence on the eventual recovery of gold by cyanidation. Surface analytical techniques such as scanning electron microscopy and BET gas adsorption have been utilized to determine quantitatively the structural morphology of calcined pyrite and arsenopyrite samples in the range of 450 to 750 °C under an oxidizing atmosphere. In the case of. pyrite calcines a highly porous hematite product was found below 500 °C; at higher temperatures, a coarser oxide network , was observed. The surface area of these calcines was found to decrease sharply with increase in temperature. In contrast, the surface area of arsenopyrite calcines was found to follow a bimodal-type behavior with roasting temperature with maxima at 500 and 625 °C. In the case of pyritelarsenopyrite mixtures, the surface area was observed to increase dramatically as the content of pyrite increased. The appearance of pyrrhotite as an intermediate phase in the oxidation reactions is postulated to have important structural implications.

Jan 1, 1984

By H. P. Stüwe

HE recent papers of Aust and Rutter112 have again brought to mind the importance of certain "special" orientation relationships between the lattices of two fcc crystals on the mobility of the grain boundary separating them. No theoretical treatment of this problem has been offered till now. The only principle published so far that has given an indication why certain orientation relationships should be "special" is the counting of "coincidence sites" according to the suggestions by Kronberg and Wilson.3 The "coincidence plots" published by these authors show, for instance, that two fcc lattices rotated by 38 deg around a common (111)-axis have 1/7 of their lattice sites in common. Such an orientation relationship is also characteristic for high boundary mobility. The accuracy of the orientation relationship needed for high mobility is not too rigid. Deviations up to 10 deg from the ideal orientation seem to be tolerable as can be gathered from the experimental data.&apos;j4 The auestion arises, then. how the density of coincidence sites will be affected by a deviatioi from mathematical accuracy. This can be checked by a simple model. Two sieves are prepared, the arrangement of the holes corresponding to lattice sites on a (111)-plane in a fcc crystal. They are placed upon each other, Fig. 1. One is kept fixed, the other is rotated around an axis pushed through one hole in common to both. The light falling through holes of both sieves is then a measure for the density of coincidence sites. If the diameter of the holes is very small, light intensity is contributed only by holes the centers of which coincide "exactly." If the diameter of the holes is rather large, some intensity will be contributed by

Jan 1, 1962

By C. R. Ross

"The purpose of this paper is to review the activities of international organizations concerned with the problem of dust hazards in mines and to indicate the extent of Canadian participation in these activities. The work of the International Labour Office in sponsoring conferences and reports on the appraisal and control of dust hazards and in the development of standard radio-logical classifications is considered in some detail. Also discussed are the role of technical societies, such as the American Conference of Government Industrial Hygienists, in the development of proposed standards for dust exposure and the functions of international committees concerned with particular hazards, such as the U.I.C.C. (Inter-national Union Against Cancer) Committee on Asbestos and Cancer."

Jan 1, 1969

By Byung-Su Kim

The reaction between calcium sulfate and hydrogen is of interest both as a means of regenerating calcium sulfide as a reductant of sulhr dioxide to elemental sulhr and for producing elemental sulhr from gypsum. This reaction was investigated using a thermogravimetric analysis technique in the absence and presence of nickel catalyst. The reaction temperature was varied between 973 and 1153 K, while the hydrogen partial pressures of 12.9 - 86.1 kPa were utilized. At 1073 K and a hydrogen partial pressure of 86.1 kPa, 60 % of the original calcium sulfate in the absence, and 95 % in the presence, of the nickel catalyst was converted to calcium sulfide in one hour.

Jan 1, 1999

By J Charbucinski

Commonwealth Scientific and Industrial Research Organisation (CSIRO), Exploration and Mining, has developed nuclear spectrometric techniques for borehole logging. The paper reviews the latest developments of this technology for the metalliferous mining industries. The SIROLOG logging system developed by CSIRO Exploration and Mining has been commercialised and is available to the mining industry.

Jan 1, 2000

By William D. Siapno

Approximately a century lapsed between the time nodules were discovered and the beginning of commercial exploration in the early 1960&apos;s. A period of rapid development of exploration and mining technology ensued over most of the next two decades. In recent years advancement has been sharply curtailed. This paper discusses the constraints inhibiting nodule mining and some developments that could aid in overcoming certain difficulties. Specifically, the greatest single constraint is economic. With few exceptions mineral markets are badly depressed. Present projections for development of nodules are for the late 1990&apos;s or beyond. However, the U.S. awarded exploration licenses in mid-1984 and more recently boundaries of license areas have been released. These conditions promote cooperation among organizations engaged in deep ocean mining. Survey data, and where appropriate some data products, have been exchanged between various consortia. The present hiatus in at-sea activities provides an excellent opportunity to investigate the best means to proceed. This period of quiescence offers a rare moment to distill the meaningful values of an era of hectic activity to permit more efficient development in the future.

Jan 1, 1985

No. 484.-A mining engineer and geologist of long and varied experience in North and South America is open for an engagement. Exploration and development work preferred. Rare minerals a specialty. No. 485.-Member, mining engineer, technical graduate, married, age 28, exempt, with 9 years experience at gold and silver, copper, lead, and coal mines, 4 years with present employers, is open for engagement as mine superintendent or foreman, or in charge of cyanide plant. Boston or New York interview after Oct. 10. Present position, day foreman at producing gold-silver mine in Montana. References. No. 486.-Member, age 34, married, varied experience in iron, copper, nickel, talc, etc., principally as surveyor, mine and surface geologist, and superintendent of explorations, is open for engagement. Preference, connection with some eastern consulting engineer or firm of engineers. No. 487.-Member, mine superintendent, 18 years&apos; experience in the West and in the Lake Superior districts. Thorough business and technical training. Personal interview, preferably Chicago.

Jan 10, 1918

An iridium oxide coated titanium electrode was tested as anode in copper electrowinning. Initial results confmed that the DSA-type anode was significantly more active for oxygen evolution than traditional lead anodes. However, during longer runs, the anode potential was observed to increase linearly at a rate of 220 mV/year. Scanning elecuon microscopy (SEM) and energy dispersive spectroscopy (EDS) showed that the anode passivation could be attributed to elecuochemical dissolution of the coating. The effect on the anode potential of organic additives (glue and thiourea) and lead in solution was also examined. A preliminary economic evaluation of the anodes is given.

Jan 1, 1992

By Tomoya Kawasaki, Tatsuya Motomura, Yutaka Yasuda

Saganoseki Smelter, one of the largest copper producers in Japan, currently operates a single flash smelting furnace to produce 450,000 tons of new copper annually. The smelter used to employ two flash furnaces, and integrated the two into one in 1996. Since then, various improvements to its facilities and technologies have been made to increase productivity. To upgrade the operation efficiency, "stability" was considered a key issue, and the measures were taken to increase the operation and facility reliability. Currently, the furnace is running at a feed rate of 215 DMT/h, while the furnace utilization has been maintained at 97%. This paper outlines recent improvements that have made to increase furnace productivity and efficiency.

Jan 1, 2014