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By J. G. Kim, B. G. Chae, D. S. Cheon, E. S. Park

The underground structures such as high-level radioactive waste disposal thermal energy storage should be designed and constructed considering thermal-mechanical characterization because of long term and/or cyclic thermal stress. High temperature changes in these structures can extend the existing cracks and generate new cracks in surrounding rock mass. In case of long term and/or cyclic thermal stress conditions, it is possible to lose the function of structures caused by the significant cracks and fracture growth in the rock mass. In this study, the critical thermal crack temperature of the granite, limestone and thermal Kaiser effect were evaluated. Experiments were carried out with the heating speed of 1.5?/min. To avoid thermal shock and target temperatures were set at 150? and 250?. In order to verify the thermal Kaiser effect, the samples were heated by 150 ? after 2-3 repetition to 250?. The generation and growth of cracks were observed through an acoustic emission measuring system. The variation of the physical rock properties was measured before and after thermal experiments. After compared with the thermal experiments using PFC2D, numerical simulations were carried out at higher temperatures (400?). The experiments showed that the initial thermal crack temperature of granite and limestone is about 35?, 32? and the critical thermal crack temperature were about 69? , and 49? , respectively. The experiments confirmed the thermal Kaiser effect of experimented granite and limestone due to thermal cyclic loading. From the numerical analysis, the critical crack temperature showed the same tendency as the thermal experiments. The P and S wave velocity of the sample after the experiment were reduced. Therefore, when heat is applied in long-term and repetitive conditions, these cracks may affect the function and stability of the underground structure. Therefore, further studies of thermal stress effects should be performed.

Jan 1, 2015

By Tom Gaines, G. S. Brant, J. G. Debanne

"AbstractThe Bonnie Glen oil field, one of Canada's largest, lies about fifty miles southwest of Edmonton, Alberta. One hundred and thirty-eight wells have been completed in this field since its discovery in January, 1952. Five different procedures have been used in completing the producing wells.The reservoir is an Upper Devonian biohermal reef with good porosity and uniformly high permeability. The top of the reef is quite flat but the flanks slope at angles approaching 20 degrees from the horizontal. The reservoir has a gas cap with a maximum thickness of 400 feet, an oil column of 300 feet, and a :porcus aquifer of over 300 feet. The reservoir pressure is now 2,400 pounds per square inch gauge at datum ( -4100 M.S.L.).Because of the high permeability and the high •pressure, lost circulation and resultant blowouts are a particular hazard in drilling at Bonnie :Glen field. To reduce the dangers of blowouts, it is general practice to run casing to the top of the reef. If the reef is encountered 'high' it was usual practice to run a liner and perforate for completion. Wells penetrating the •reef below the gas/oil interface were either completed in open hole or through casing perforated opposite the oil pay, with the former method more frequently used. Eight wells were completed by the Humble-Otis permanent-type completion, and recently five high wells were completed open hole with the gas •cap exposed. This latter completion, 'tubing submergence', has proved highly satisfactory thus far.The open-hole type of completion is cheaper than the liner perforation method and results in better well performance. More experimentation and data are needed before the tubing submergence method can be recommended unqualifiedly. but all evidence thus far favours its use in reef reservoirs."

Jan 1, 1955

By Afshin Sadri, Wai Lai Ying, Brycklin Wilson, Zoe Coull

"Although there have been great steps forward to integrate corrosion engineering into operations, there is still an underlying tendency for maintenance tasks to be performed in a reactive manner. This is especially true when strategies focus on lagging indicators such as visual inspections, RCA (root-cause analysis), and FMECA (failure mode, effects and criticality analysis). This trend to “reactive maintenance” can be avoided by utilizing more inspection and monitoring methods to identify leading indicators of failures. Prevention is generally less costly than repairs; moreover, when paired with appropriate monitoring techniques, intervention of corrosion protection can be more effectively timed and based on more accurate data. Hatch asset reliability studies show nearly 80% of defects are introduced through operations and maintenance. Therefore, proactive corrosion management can provide the necessary feedback to optimize operations and maintenance strategies preventing costly corrosion losses. Understanding corrosion risks gives a clear picture of the benefits of a proactive approach to asset performance. Monitoring techniques (Non-Destructive Testing, field testing, sampling, etc.) by nature are a more effective means of improving maintenance efforts and preventing corrosion losses than other methods (RCA, FMECA). This paper will outline the importance of proactive corrosion management and demonstrate its benefits through industry examples.INTRODUCTION Over the past few decades, with the growth of technology and awareness of sustainable development many studies have shown the benefits of a proactive approach to maintenance strategies. However, in practice there is still an underlying tendency for maintenance tasks to be performed in a “reactive manner”. This is especially true when strategies focus on lagging indicators such as visual inspections, RCA (root-cause analysis), and FMECA (failure mode, effects and criticality analysis). This trend to “reactive maintenance” can be avoided by utilizing more inspection and monitoring methods to identify defects and leading indicators to failures."

Jan 1, 2017

By V. G. Papangelakis, G. A. Moldoveanu

The use of anhydrite (AH) seed, control of acidity levels and ageing were assessed as means to promote the conversion of freshly produced metastable gypsum generated in-situ to the less soluble anhydrite phase and force deposition of calcium sulphate on seed as opposed to on equipment as scale, while achieving lower terminal aqueous calcium concentration as well. It was found that moderate sulphuric acid levels (0.25M) and ageing in the presence of AH seed accelerated the gypsum-AH conversion, achieving 100% transformation of the metastable gypsum generated in situ to the more stable, less soluble AH in 6-7 days, while lower/nil acidity did not promote more than 30% AH conversion for 10 days, even in the presence of AH seed. These findings indicate that anhydrite seeding, ageing and incomplete neutralization are beneficial for scale control as well as achieving lower calcium levels, thus rendering the resulting solution more amenable for recycling.

Jan 1, 2015

By Y. Kashiwaya, J. Yagi, P. R. Austin

The problems of global environment and resources have become important issues in recent years, and the iron and steelmaking industry is requested to decrease energy consumption and carbon dioxide emission. The improvement of efficiency of ironmaking system is one of the countermeasures for these problems because more than a half of total energy input to the integrated steelwork is input to the ironmaking system. Various approaches to improve the blast furnace process have been made. The authors examined their performances through mathematical simulations of blast furnace operation, and confirmed the improvement of blast furnace efficiency under some operating conditions. The ironmaking system consists of various processes, and the materials and the energy are transported among these processes. Thus it is necessary to evaluate the efficiency of the novel operation of blast furnace based on the ironmaking system. In this study, the balances of material and energy on ironmaking system that consists of blast furnace, coke oven, sintering and hot stove processes were analyzed. The operation status of each process in the system was adjusted according to the results of the operation simulation of the blast furnace under novel operating conditions. The analysis clarified the effect of the blast furnace operation on the energy balance and CO2 emission of the ironmaking system.

Jan 1, 2015

By M. Proulx

"RÉSUMÉ Le diagramme ternaire Al2O3-Sr-Y est un nouvel outil servant à l’exploration de gisements de sulfures massifs volcanogènes (SMV) archéens. Le diagramme permet de discriminer entre les roches volcaniques à minéralisations à zinc dominant (domaine Zn+) et celles à minéralisations à cuivre dominant (domaine Cu+), ainsi que les roches volcaniques ayant subi une chloritisation hydrothermale pouvant aboutir à la formation de chloritites associées aux cheminées d’altération (domaine Cl+). Ces trois domaines délimitent des zones d’influence géochimique ou d’empreintes hydrothermales résiduelles ou fossiles produites par les cellules de convection hydrothermales générées par des magmas. Le diagramme permet aux sociétés d’exploration de déterminer de façon peu coûteuse la fertilité potentielle des roches volcaniques archéennes en ayant recours à leurs bases de données et aux résultats de leurs analyses de terrain, sans aucune manipulation des données. Le diagramme ne s’applique pas aux SMV aurifères.ABSTRACT The tertiary diagram Al2O3-Sr-Y is a new tool to explore Archean volcanogenic massive sulphide (VMS) deposits. The diagram can be used to discriminate between the volcanic rocks where zinc is the dominant mineralization (Zn+ domain) and the rocks where copper is the dominant mineralization (Cu+ domain), as well as the volcanic rocks that were subjected to hydrothermal chloritization that could have led to the formation of chloritites associated with alteration chimneys (Cl+ domain). These three domains define the zones of geochemical influence, or residual or fossil hydrothermal footprints produced by hydrothermal convection cells generated by magmas. Exploration companies can apply the diagram to determine, at low cost, the potential fertility of the Archean volcanic rocks by using their databases and the results of their field analyses, without any data manipulation. The diagram does not apply to gold-bearing VMS deposits."

Jan 1, 2015

By S. C. Cohen, A. F. Mikkelsen

"This paper describes the improvements made to the operation of a liquid phase, 300°C, heat transfer system in the paste plant of an aluminum smelter. These improvements were achieved by replacing the original heat transfer fluid, a synthetic aromatic, with a new technology, petroleum-based product. This new fluid, Calflo HTF, provided better thermal stability, with lower toxicity, and improved plant working conditions.The procedures for fluid selection, changeout and performance monitoring are described along with a summary of control analysis over the last three years."

Jan 1, 1993

Sustainable Development SAFETY ?Safety is the most important element of sustainability. ?One bad experience or incident can mar a company?s reputation for a long, long time. ?News travels faster than ever ?Internet, blogs, texting, peer-to-peer communication, etc. and unfortunately sometimes the information is not always accurate. ?Rarely do we hear in the news about the mining companies or projects that are done safely ?we always hear about the exceptions. ?Safety is just like TQI / TQM ?the process of improving can never stop.

May 1, 2010

By K. Horikawa, S. Kitahata, H. Kobayashi

"It has been clarified that the Al-5%Mg alloys containing 200 mass ppm of sodium showed grain boundary (GB) fracture, even when tested at room temperature, as well as at high temperatures (~500°C). SEM/EDX study revealed that the GB fracture was associated with the segregation of sodium on grain boundaries of the Al-Mg base alloys. Differential scanning calorimetry (DSC) revealed that the GB fracture at room temperature of Al-Mg alloys was caused by sodium segregation in the solid state. It was also shown that the tendency of the GB fracture strongly depended on the heat treatment; the alloys after the solution heat treatment showed severe GB fracture compared with the alloys after the homogenizing treatment. Moreover, it was shown that the GB fracture at room temperature by sodium segregation was suppressed by the addition of bismuth or indium. The suppression of the GB fracture by the additional elements was believed to be the scavenging effects by forming the sodium bearing compounds in grains.INTRODUCTIONIt is widely known that Al-Mg base alloys containing high amount of magnesium(~5 mass%)show better workability at room temperature, while that the alloys show grain boundary (GB) embrittlement at higher temperatures ranging from 200 to 500°C, depending on grain size(Otsuka, 1984), sodium impurity level(Ransley, 1959, Okada, 1997, Horikawa, 2001)and testing strain rate(Yamada, 2012). In the case of coarse-grained Al-5%Mg alloys (~300 ?m), 2 mass ppm of sodium causes severe GB fracture around 300°C, however, the Al-5%Mg-2ppm alloy does not show GB fracture at room temperature. It has also been shown that the GB embrittlement caused by 2ppm of sodium was suppressed by the additional elements, such as bismuth (Talbot, 1995), antimony (Ueda, 1997) and indium (Horikawa, 2012). Basedon these facts, we have concluded that the GB embrittlement at higher temperatures of Al-Mg alloys is attributed to the synergy effects of GB segregation of atomic sodium and GB sliding. For the GB embrittlement mechanism of Al-Mg alloys, involvement of low melting point metallic phases has been pointed out (Lynch, 2002),since the GB embrittlement appeared only at high temperatures. Up to date, the effects of high amount of sodium addition more than 2 ppm on GB fracture were not fully investigated in Al-Mg alloys. In the present study, the effect of 100 ppm ordered sodium impurity on GB fracture of Al-5%Mg alloys was examined, together with the effect of another additional elements."

Jan 1, 2017

By J. Stumper

The control of the distribution and movement of liquid water is crucial for increased reliability and durability of PEM fuel cells: whereas the proton exchange membrane requires a minimum amount of liquid water for optimum operation, water excess in the GDL will impede reactant gas access to the catalyst layer thereby reducing performance. In order to understand the relationships between water management on one hand and fuel cell performance and durability on the other, Ballard has been developing a number of minimally invasive techniques that can throw light on the role of liquid water for both cell performance and durability. This paper introduces a novel measurement method that can provide information about the amount and distribution of liquid water under operation. It is shown how the MEA Resistance and Electrode Diffusivity (MRED) method can be used to determine i) the amount of liquid water in the fuel cell, ii) the pure ohmic cell resistance and iii) the O2 -diffusivity of the cathode. Furthermore, through a combination of the MRED method with current mapping it is possible to determine spatially resolved MEA resistance profiles.

Jan 1, 2005

By J. E. Tupper

"This paper will discuss strategies for the introduction of computer technology in the mine environment. More specifically, it will focus on issues such as: (a) make or buy; (b) programmer less mines; and (c) support from corporate groups.The paper relates these strategies to systems for mine operations. These will be illustrated by considering the implementation of some phases of these systems at Teck Corporation.IntroductionThis presentation addresses some of the major considerations in a strategy for mine computerization and then relates these considerations to the computerization cycle and Teck Corporation.Strategy is defined as a conceptual framework or plan to accomplish a goal. For purposes of this paper, the goals can be more simply defined for operational purposes as either increasing revenue or decreasing costs.The strategy will allow us the framework for measuring tactical decisions such as computer and software acquisitions.The Mine Life CycleTo start with, let us look at the mine life cycle from a computer systems point of view:-Exploration-Property Development-Feasibility-Construction-OperationFrom a systems point of view, the exploration cycle is oriented to geophysical and geochemical computing. Property development starts with drilling and building the geological data base. The feasibility cycle includes all stages of evaluating the decision to proceed with mine development: ore reserve calculations; mine planning; and financial projections. Construction includes project management and project accounting systems. Systems required for operation are those needed by personnel at the mine site."

Jan 1, 1982

By N. Fukatsu

The recent development of galvanic cell-type hydrogen sensor for molten copper was outlined. The principle of the sensing mechanism, the fundamental structure of the sensor, and its performance as a process control device are discussed based on experimental work undertaken by the authors. Besides sensors based on usual perovskite-type proton conducting oxide, those using magnesium-doped alpha alumina, which was recently known as a proton conductor, were investigated and the results at the laboratory scale are reported. Considering the excellent sensitivity at high temperature and the stability to the disturbance from the attendant oxygen activity, magnesium-doped alpha alumina was regarded to be a superior material for the sensors used for such purposes.

Jan 1, 2007

By O. A. Ojo, N. Esmaeili

"The effects of brazing and use of composite powder mixture as interlayer material on hot corrosion resistance of brazed IN738 superalloy were studied. Brazing was observed to result in significant reduction in the hot corrosion resistance of the superalloy. However, application of composite powder mixture, which consists of additive superalloy powder, enhanced the hot corrosion resistance of brazed samples. It is also found that although the use of composite powder mixture increased hot corrosion resistance of brazed alloy, if the additive powder completely melts, which is possible during brazing, it can significantly reduce the hot corrosion resistance of the brazed joint. Elemental micro-segregation during solidification of the joint with completely melted powder mixture produces chromium depleted zones and consequently reduces hot corrosion resistance, since a uniform distribution and adequate chromium concentration is necessary to combat hot corrosion. This has not been previously reported in the literature and it is crucial to the use of composite powder mixture for enhancing the properties of brazed superalloys.INTRODUCTION Superalloys have been developed in response to the increasing demand for materials with higher resistance to corrosion and creep and also with higher mechanical strength at higher temperatures (Smith, 1981). Ni-base superalloys are predominantly used in manufacturing hot sections of gas turbine engine components. This is due to their high strength and corrosion resistance in extremely high temperature service environments which is typical for hot sections of gas turbine engines (Miglietti, 2009). The continuous demand for higher efficiency and output has resulted in the use of higher operating temperatures and gas pressure in modern gas turbine engines (Jahnke & Demny, 1983). Consequently, this has caused thermal and mechanical stresses which result in severe degradation and damage of gas turbine engine components due to creep, fatigue and hot corrosion (Zhang, Feng, & He, 2006). The decision to replace or repair damaged parts depends on the overall repair cost and expected life of the repaired components (Jahnke & Demny, 1983). However, in most cases, it is more cost effective to repair damaged parts rather than use a full replacement."

Jan 1, 2017

By Jacques H. Nantel, James F. Archibald

"Frozen tailings material may be required, in the future, to perform the support functions of underground backfill in mines located in zones of permafrost, notably in the high Arctic. To date, no knowledge of physical support parameters of such materials has been obtained in Canada due to the limited mining activity in permafrost regions. It is therefore judged essential that the important physical and mechanical properties relating to frozen tailings material be assessed.Innovative mining methods will be required to cope with the harsh environmental conditions that exist at mining sites in the Canadian Arctic. A preliminary laboratory study, in the absence of field trials at limited Arctic mining sites, has been completed in which the physical and mechanical properties of several types of representative mill tailings mixtures have been investigated. A variety of tests, to determine frozen slurry and pelletized tailings strength properties, moduli of compression, optimum water contents, deformation characteristics and the like, have been conducted.The results of this study will be used to establish guidelines for the suitability of tailings use in such northern mining environments. IntroductionFrozen tailings material has never been used to backfill underground openings in Canadian mines. At present only one Canadian mine, the Polaris Mine situated on Little Cornwallis Island, is investigating the use of frozen backfill. However, the Canadian North covers a large territory and potentially contains a large number of mineral deposits. The understanding of concepts related to mining activities in sub-zero frozen ground is therefore important.The implications of using frozen tailings as underground backfill material are far reaching both from the point of view of mine stability and disposal of tailings in the arctic regions.The strength of frozen materials (soil, backfill, etc.) may take on different meaning depending on the engineering situation. Both the concepts of rupture and excessive deformation need to be considered.The functions usually required to be performed by the backfill material in underground mines may be summarized asfollows:a) working floors; such as in cut-and-fill stopesb) stope wall support; for cut-and-fill and delayed fill stope~c) self-support when backfill is exposed on one face; during pillar recovery phases.For fill functions such as working floors, the short-term response of the frozen fill is the dominant concern. For the other fill functions, the long-term deformation response of the frozen fill, or creep, is of interest."

Jan 1, 1986

By S. M. Chentouf, M. Jahazi, N. Bombardier, T. Belhadj

The main limiting factor in the commercial expansion of superplastic forming (SPF) of thin sheet aluminum alloys is the extent of cavitation phenomenon that takes place during the processing. The severity of the cavitation process is mainly dependent on the uniformity of deformation (i.e. level of local thinning) during processing. In the present paper, correlations are made between thickness variations in several formed sheets and the characteristics of the cavities observed in the material. The 1.4 mm thick 5083 aluminum alloy sheets were hot pre-formed at around 450°C for 4 min and then air-cooled. Opto-digital and Scanning Electron Microscopy were used to examine the microstructure and analyse the cavities. Also, grain size measurements were carried out for different location in the SPF formed piece. The surface and volume fractions of the cavities were measured with the aid of metallography image processing (MIPTM) on as-polished samples prior to etching. The results are analyzed in terms of the influence of applied strain and microstructure conditions on the propensity to cavitation of the alloy.

Jan 1, 2015

By Zihe Ren, Edouard Asselin, Marcus Tomlinson, Tianbi Zhang, Jing Liu

"Raman spectroscopy is used to quantify the extent of disorder in the carbonaceous matter associated with preg-robbing ores. Previous studies of Goldstrike ores showed that the height and width of the peaks for the “D” (disordered) and “G” (graphite) bands, the so-called “Raman ratio” had a strong correlation to the preg-robbing value (PRV) measured for various ore samples. A brief literature review on Raman spectroscopy as it applies to preg-robbing ores is presented. Further, recent studies, presented here, have shown no correlation between the Raman ratio and the PRV for a wide variety of ores. This suggests that the extent of organic carbon crystal disorder is not the main factor in determining preg-robbing characteristics.INTRODUCTION Preg-robbing may arise from natural carbonaceous materials in the ore. Several mechanisms have been proposed in the past decades including a physical sorption process by the carbonaceous matter, or via the reduction of aurocyanide at the mineral surface (Abotsi & Osseoasare, 1986; Afenya, Osseoasare, & Abotsi, 1983; Tan, Feng, Lukey, & Van Deventer, 2005). Nevertheless, the mechanisms of preg-robbing remain poorly understood. Understanding the nature of the preg-robber is of practical importance for the selection of a suitable treatment process. Fine carbon particles in the ore have been recognized as preg-robbers due to their similarity to the activated carbon used in the carbon in leach (CIL) or carbon in pulp (CIP) processes. Previous research has illustrated that the activated carbon (also referred to as amorphous carbon in some literature) has a much higher absorption ability than pure graphite with high crystallinity (Adams & Burger, 1998). Adams et al (Adams, Swaney, Friedl & Wagner 1996) concluded that carbonaceous matter is largely responsible for the overall preg-robbing capacity of a given ore. However, the mechanism of carbon preg-robbing was still not clear mostly due to the complexity of amorphous carbon and its behavior in different solution matrices, and at different pH and temperature (Adams, 1990, 1993)."

Jan 1, 2017

By James A. Deeks

"Motor failures and equipment bearing failures are responsible for reduced productivity.With the introduction of computers and data acquisition systems, users are now able to monitor, report and trend deteriorating conditions and take corrective action before a critical shutdown occurs.This paper discusses the monitoring and trend analysis of' motors, and motor and equipment bearings. With today's digital electronics technology users are now able to monitor their equipment, detect deteriorating or abnormal conditions quickly, alarm the condition locally and or remotely, and decide if immediate corrective action is necessary or if it can be delayed until the end of a work Shift. All of this can be done long before any damage is done to the equipment.Monitoring Trend AnalysisIt is no longer necessary to compromise in selecting products, since state-of-the-art designs allow the adjustment in such small increments that the users are able to detect minute changes in a system's performance.Monitoring and trending of motors and equipment bearings is now available in economical packages which can be expanded as a system grows. Simply select the information you need, set the parameters, choose the scan time, and decide on the degree of reporting.Buffer storage of short-term monitoring of a number of analogue channels permit the user to view the recent history of motor data such as: motor average load, unbalance, motor current, ground fault, reserve thermal capacity, plus all of the settings of the protective device.A decision can be made to freeze the stored information after the motor stops or after the motor starts. Then the user is able to recall the conditions and diagnose the performance and the cause of the abnormal condition. Typical scan times range from ¼ second to 5 seconds ."

Jan 1, 1992

By X. B. Wang, Z. Q. Guo

Slagging coal gasification process became a highlight of coal chemical industry in China during the last decade. Refractory lining's life of slagging gasifiers is one of the most critical factors for a cost-effective operation. The paper introduces current status of coal gasification in China, lining structure of slagging gasifiers and performance of refractory lining. It also summarizes the major factors impacting on refractory wear in slagging coal gasifiers in four Chinese chemical plants, based on ten years of industrial experience. The utilizability is discussed in terms of cost-effectiveness of high chromia refractories and possibility of the alternatives.

Jan 1, 2004

By Haruka Takeura, Tomoaki Murata, Kazunari Yoshida, Masato Adachi

"Pure magnesium is a material with high functionality, however, the cold drawing of this material is very difficult, that is why, until this day there are no optimal cold drawing conditions. Furthermore, cold drawing of pure magnesium wire shows a problem with internal defects that occurs under certain conditions. In this research, the aim is the suppression of internal defects, and final target is to create the optimal cold drawing conditions for pure magnesium wires. The first step is the investigation of the drawing limit by using 250°Cannealed wire. As a result, reduction of 10% per pass was chosen for stable wire drawing. However, in this case, it was found that internal defects occurred at total reduction of over 45% during drawing. Investigation of intermediate annealing conditions that can suppress internal defects, and influence on internal defect that the die half angle and reduction per pass. As a result, it was found that the drawing condition capable of suppressing internal defects most efficiently was 13% reduction drawing by using under 6°half angle die. Consequently, it’s possible to manufacture a cold fine drawn pure magnesium wire of 100µm, without defects in the center of the wire and hindering its mechanical properties.INTRODUCTIONMagnesium is a light and high functionality material that has high vibration absorbency, heat dissipation, electromagnetic wave-shielding and recycling efficiency (Conruy, 1989). However, proper cold wire drawing conditions haven’t been established, that is why warm or hot processing is commonly used (Oishi, Mori, &Kawabe, 2005). As a result, strength improvement of the wires is not possible, that is why the production of medical tools is disregarded. If it was possible to cold draw magnesium wires, the applications for material products would expand. Further, in wire drawing such difficult processing material, if appropriate processing conditions are not selected, defects will be generated inside the drawn wire."

Jan 1, 2017

By W. D. Freeborn

Slim-hole drilling and completion techniques were first used in the Cynthia area of the Pembina field, Alberta, by the Texaco Exploration Company in the summer of 1957. Prior to that time, eighty-eight wells had been drilled and completed in this area in a conventional manner. Subsequent to the initial four-well evaluation programme, twenty-one additional wells have been drilled using slim-hole techniques. No difficulty was encountered in the drilling and completion of slim-hole wells, or in obtaining production from them. A comparison of drilling and completion economics and practices has been made for slim-hole and conventionally completed wells. Penetration rates for both bit sizes (614 in. and 9 in.) were relatively equal. The shorter life of the smaller bits required the use of 15 per cent more bits per well, but the total trip time to change bits was similar for both hole sizes because of the higher hoisting speeds possible with the lighter drilling strings used in the slim holes and better hole conditions. Completion costs of the slim holes were reduced by 37 per cent as compared to the costs of conventional-type completions. This was made possible through the use of smaller well equipment, the elimination of tubing, and a reduction in rig time for completion operations.

Jan 1, 1958