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By Y. Mitani, H. Ikemi, K. Kitamura, H. Honda

"Instead of carbon capture and geological storage (CCS) that does not rely on structural aquifers, injecting carbon dioxide into sedimentary rock deep underground has been considered. For advection velocity of the fluid is slow, the permeability of sedimentary rock deep underground is low. In order to perform the CCS on the low permeable sedimentary rock, it is necessary to clarify the behavior of long term storage properties of carbon dioxide (CO2).In this study, the permeability and storativity of CO2 injected into low permeable rock has been evaluated. The injection of supercritical CO2 has been conducted on the specimen of Ainoura sandstone (unit weight: 2.39 g/cm3, porosity: 11.9 %) saturated with water by using flow pump method. The experiment has been set up to reproduce the similar condition of deep underground reservoir under 20 MPa confining pressure, 10 MPa pore pressure, 35°C temperature and 3 µl/min CO2 injection rate. In order to prevent an increase in pore pressure, the boundary condition on the outlet side of specimen has been kept a constant pressure.As a result, it has been possible to observe step by step the change of the differential pressure between both ends of specimen. Furthermore, the relative permeability and specific storage of rock under supercritical CO2 injection has been examined by the theoretical analysis of flow pump permeability test incorporating Darcy’s law for two-phase flow. It is observed that CO2 has been transmitted gradually while CO2 stored in the rock. It is also clarified that residual water has existed in specimen after showing the constant differential pressure in the end of the experiment. Using the results of the experiment, 3D core-scale flow-simulation by using TOUGH2 has been conducted due to confirm the flow of fluid and CO2 distribution in the specimen. From the experimental results and analytical solution to them, permeability and storativity are identified, and simulation results support the validity of the experimental results."

Jan 1, 2015

By W. R. McQuarry, M. E. Wilson

"The structural relations of the ore deposits of the Staclacona mine are of considerable interest, for they not only illustrate the effect of a change in competence of the wall-rock, but also the effect of either the convergence together of two faults, or a change in the clip of a fault, or both of these factors, on ore deposition.The mine is in claim M.L. 1818 near the eastern end of Pelletier lake and lies about 2 miles south of the town of Rouyn. The Company was organized in 1926 to explore claims in Rouyn, Dufresnoy, and Beauchastel townships, but attention was directed mainly to those in Rouyn. Underground work began in 1928 with the sinking of the main shaft to a depth of 300 feet. Except for 1930 and 1931, the mine has been in operation continuously since that time. Production, which began in 1936, up to the end of 1946 has amounted to 1,381,422 tons of ore from which gold and silver having a total value of $7,861,860 were recovered. The average grade of the ore milled in 1946 was $6.68.GEOLOGYThe rocks in which the Stadacona ore deposits occur are mainly volcanics of the (Keewatin) Abitibi series intruded here and there by numerous dykes, sills, or masses of diorite. Single dykes of olivine diabase and lamprophyre are also present in the property and are intersected in the mine workings. The volcanic rocks are part of a wide belt of northward dipping lavas and pyroclastic rocks, having a thickness of over 16,000 feet, that extend from the east-west trending belt of Timiskaming sediments on the south northward to the Horne Creek fault and form the south limb of a large syncline. The volcanic rocks within the property consist of numerous, east-west trending, northward dipping flows of andesite and a few flows of rhyolite interbedded with rhyolite ruff and agglomerate. The angle of dip throughout most of the property is 60° to 80°N., but in the main cross-cut on the 850- and 975-foot levels stratification in rhyolite tuff was noted dipping 35°N. The tuff at this point lies above an intrusive mass of diorite and it is probable that the change in dip results from the way in which the tuff and agglomerate have been thrust aside by the intrusive."

Jan 1, 1954

By T. B. Williams

THE British Columbia Coal Control was established in 1946 as a branch of the Department of Lands. Its functions are the administration of the Goal Act, the making of field and laboratory investigations bearing on the delineation and utilization of British Columbia coal deposits, and the dissemination of information concerning them. The Department of Lands in the Province of British Columbia retains and administers many of the Province's resources until such time as they are actively developed under the departments of Agriculture, of Forests, of Mines, etcc. The work of the Control is one of stock taking and appraising. We are picking up where the geological surveys leave off. In an effort to assist in the orderly, scientific development -of our excellent and extensive' ?Coat resources, we are bridging the gap between exploration and geological examination on the -one hand and mining on the other. All coal analyses required in the course of the investigations, together with? those requested by prospectors and others, are carried out in the very modern and efficient laboratories of the Coal, Petroleum, and Natural Gas Control. At its inception, the Coal Control began an investigation of coal seams in the Peace River area, specifically those contiguous to the Pine River valley about one hundred miles west of Dawson Creek. The occurrence of coal in the Peace River canyon, east of Hudson's Hope, bad been known since 1792, but the first record of production is for 1923.

Jan 1, 1951

By R. R. Rogers

Introduction The subject of cathodic protection is not new. In 1824 Sir Humphry Davy, in publishing the results of his investigations for the British navy, pointed out that copper could be protected from sea-water corrosion by connecting it electrically with zinc or iron. Since that time much work has been clone in this field, particularly in the protection of metals from the action of sea water, neutral brines, and treated and untreated waters. Special mention should be made of the successful protection of underground pipe-lines which formerly were badly corroded by the water in the ground. So far, magnesium alloy and zinc anodes have been the most popular. However, fairly recent work has indicated that aluminium anodes will give good service under certain conditions. The principle of cathodic protection has been applied extensively in coating steel articles with zinc and in cladding aluminium alloy sheet with pure aluminium. A valuable discussion of the fundamentals and applications of cathodic protection recently was presented in the Corrosion Handbook. A useful list of references was included in the article.

Jan 1, 1949

By P. Reyes

The Codelco Chile El Teniente Division Caletones Smelter has an objective to smelt 1,250,000 tonnes per year of copper concentrate. This is a great challenge for the smelter facilities and particularly for the acid plants. The analysis ensuring that there are no obstacles to achieve the production capacity was of great importance. Therefore a series of activities were undertaken as well as studies dedicated to reach the target. This paper presents work focused on a fluid dynamic study, translated in an operation methodology of integrated handling of the smelting and converting gases with the objective to optimize the gas flow and S02 concentration. The optimization should be done employing the current installations, equipment and instrumentation and/or minor modifications. In the first part of the work the condition of the instrumentation involved in the gas handling was checked, improvements determined and the corresponding corrective actions were carried out. The proposed operation method consists of operation of the Cleaning Gas Plant 2 (TC' s gases) and operation of Gas Cleaning Plant 1 (the remaining gas plus the gases from CPS). The implementation of the operation method involves the modification of the valve of the gas into the duct to plant 1 from On to Off to modulate flow. After modification a three days test was carried out. To evaluate the tests, a "Sulphur Capture" indicator was used. During the test the behaviour of the effluent treatment plants was closely examined. No problems or unusual operating conditions were observed. The reduced flow of gas to Gas Cleaning Plant No. 1 permitted the start up of the 2nd test day treating most of the gas received by Gas Cleaning Plant No. 2. The operation was carried out with the limitation not to increase the effluent pond level, which was maintained constant.

Jan 1, 2007

By P. L. Wright

"This is a brief history of the development of the mining project, with a description of the proven geology. The paper describes how the experiences gained progressively demanded change in the mine design. The equipment used is described, together with methods of working. Interesting facts have been proved regarding gas emissions and roof. supi;iort. The. working cycles evolved are completely flexible m operation and lend themselves to maximum utilization of the most productive units. The two underground mines are compared, showing the variance in conditions already experienced. Programs currently in operation to improve standards and production are: the training of miners, maintenance men and officials; experiments in floor consolidation and continuing roof support trials; and the effect of comparative stability of working crews on the performance of the operation."

Jan 1, 1973

By T. G. Joseph

ABSTRACT: The Canadian oil sands provide some of the harshest mining conditions in the world. Asoperations demand ever bigger tools, the toll on large mobile mining equipment is high, with structural life often half of that expected. Soft ground conditions predominantly lead to fatigue failure scenarios, poor stability, and inconsistent payload evaluations. These challenges are not solely a concern for Canadian oil sands mines; there are far-reaching implications for surface mining equipment in any poor ground-operating environment. This paper focuses on the basics of payload evaluation, motion response, and a simple estimate of structural life for haulers.

Jan 1, 2011

By G. R. Guillet

Salt is restricted to five major beds in south western Ontario, totalling as much as 200 m in thickness. These beds are located at depths ranging from 270 m to 750 m below the surface, fringing Lake Huron and the Detroit River from Windsor to Kincardine, and extending inland as far as London. Manitoulin Island, the Bruce Peninsula and the north part of the Niagara Escarpment form the northeastern rim of the Michigan Basin, a major structural depression in which the salt was deposited 400 million years ago when much of North America was covered by the Silurian sea. Salt is mined underground at Windsor and Goderich; it is also brought to surface as brine through deep wells at Windsor, Samia and Goderich. Artificially- created caverns in salt beds are extensively used for storage of liquid hydrocarbons at Windsor and Samia.

Jan 1, 1984

By M. E. Wilson

"The property of McWatters Gold Mines, Limited, is in the east-central part of Rouyn township and about 6 miles east-southeast of the town of Rouyn. It includes 35 claims, the group of 5, staked originally, and 30 claims acquired in later years. The Rouyn-Val d'Or road and the Noranda Senneterre branch of the Canadian National railway both pass within a few hundred feet of the mine.The group of claims in which the mine occurs was first staked in 1922, but gold was not discovered until August 1932 when a schistose zone including veins of quartz carrying considerable free gold was laid bare in a stripped area in the northeastern part of claim R.11604. Diamond drilling undertaken in 1932, and continued into 1933, shouwd that the gold extended for at least 1,000 feet along the strike. A 3-compartment shaft was sunk to 418 feet in 1933. A mill having a capacity of 50 tons a day was constructed in 1934, and enlarged to 150 tons in 1935. Production began in 1934 and continued without interruption to June 1944. Except for a few diamond drill holes, there have been no operations on the property since that time. The maximum depth of the mine workings is 1,50) feet. A total of 368,013 tons of ore having a value of $3,946,752 and an average grade of $11.04 was mined during the years of operation.GEOLOGYThe ore mined from the property occurred within the south limb of an eastward plunging syncline of volcanics and sediments cut off on the north by the Cadillac-Bouzan Lake fault. Because the rock formations within the syncline have been severed from those outside with which they were originally continuous, their correlation is based almost wholly on lithological similarity. They include an irregular middle zone of conglomerate and greywacke underlain by north and south bands of andesite agglomerate and andesite tuff, in which lenticular bands of pillowed andesite are included."

Jan 1, 1954

By S. Balideh

A good understanding of the behavior of broken rock helps to make more informed decisions regarding slope stability and waste dump issues in mines. The cohesion coefficient of rock has little influence on the strength of broken rock; therefore, a criterion based on friction and cohesion of intact materials does not provide an accurate analysis for the strength of broken rock. This paper illustrates the effective strength of broken rock through a brief literature review about failure of intact rock and rock masses. The complete stress- strain curve and some important points of residual strength of rock are summarized in this paper.

Jun 1, 2012

By D. Virely, M. Gasc-Barbier, J. Guittard

"The valleys of the Dordogne and the Vézère (France) have been inhabited since prehistoric times, as evidenced by the famous site of Lascaux. A few miles away, the village of La Roque-Gageac is also a very popular tourist destination (about 1.5 million tourists per year): The village is sandwiched between a massive limestone cliff and the Dordogne river. The collapse of a cave roof high above the village in January 2010 led us to characterize instability together for the cave and the whole cliff and propose a adapted instrumentation to monitor the fracture openings in the rock mass that are linked to climatic variations. Measurements have been going on and been recorded for nearly 4 years. They point out the role of thermal stress fatigue in the breakdown of the rock mass. In this paper we describe the site under study, the instrumentation and its main results. INTRODUCTIONThe phenomenon of thermal fatigue has been very little studied as far as rocks are concerned, whereas it is rather well characterized for other types of materials: Elsevier published a journal dedicated to fatigue (International Journal of fatigue). In the case of rocks, thermal phenomena and their impacts on mechanical behavior have been analyzed from a micro-structural point of view, and it is now well-known that an increase in temperature causes a dilatation of crystals (Arnould et al., 2004; Berest & Weber, 1998). This dilatation may lead to the development of inter-granular traction and compression stresses, and if those stresses are greater than fracture strength, inter-granular and intra-granular cracks may take place. On the other hand, the fatigue phenomenon (cyclic repetition of a temperature variation which is less extreme than the one that may lead to this inter-granular or intra-granular fracture) is a phenomenon which has not been much studied.The principal studies on thermal fatigue on rocks come mainly from the field of geomorphology, particularly in connection with the analysis of the evolutions of past climate that can explain the present shapes of those landforms: those studies remained essentially qualitative and not quantitative. Le Ber & Oter Duthoit (1987) proposed a thermal and thermodynamic approach to analyse the disaggregation of rock masses. This analysis is dedicated to the study of paleoclimates and was implemented to better understand the formation of slope deposits in order to propose transfer models permitting the reconstruction of the climactic conditions contemporary to their appearance. Since deterioration in the cliff only appears after several cycles, it means that it is a gradual and irreversible deterioration which leads to an increase of the « disorder ». Seen from a macroscopic system point of view, this irreversible evolution is quantified by the internal creation of entropy."

Jan 1, 2015

By R. M. T. Raja Ismail

Shipping and stevedoring industry is going to witness a massive increase in the amount of containers to be handled while land constraints become more critical. Offshore transfer operations hence offer a preferable solution to deal with the surge in cargos rather than to expand the port outwards. Recently, there has been increasing research interests on offshore crane automation. Suspended cargos in a ship-mounted crane system are caused to swing due to the vibratory motion of the ship induced by ocean waves, which can lead to collision between cargos and deck. Therefore, it is vital for offshore crane systems to satisfy rigorous requirements in terms of safety and efficiency. This paper presents the modelling and control development for offshore boom crane systems. A second-order sliding mode control law is proposed for trajectory tracking and sway suppression control, making use of its capability of actuator chattering alleviation while achieving high tracking performance and preserving strong robustness. The asymptotic stability of the closed-loop system is guaranteed in the Lyapunov sense. Simulation results indicate that the proposed controller can significantly reduce the effect of disturbances coming from gusty waves and other dynamic loadings.

Aug 1, 2013

By R. A. L. Drew, F. Jalilian, M. Jahazi

Joining of superalloy Inconel 61 7 with a foil interlayer using transient liquid phase bonding (TLP) technique was studied. Inconel 617 is a solid solution, Ni - Cr - Co- Mo alloy with an exceptional composition of high temperature strength, oxidation, carburization resistance and thermal stability. In this investigation, two bonding temperatures, 1065°C and 1150°C, and two interlayer thicknesses with joining times varying from 5 minutes to 24 hours were employed. Experiments were carried out using nickel base interlayer (A WS BNi-3) with boron as the melting point depressant (MPD) element. Joints were characterized using optical microscopy, SEM, FEG-SEM, EBSD, XRD and microhardness. The results indicated that the rate of elimination of the liquid phase with increasing the bonding temperature, holding time and decreasing the thickness of the interlayer increased. The main precipitates in the diffusion layer had platelike and blocky morphologies for both bonding temperatures and all holding times.

Jan 1, 2006

By Kevin Azocar, Jim Hazzard

"Slope stability analysis is performed most commonly using limit equilibrium calculations or numerical models assuming a two-dimensional slice through an infinitely long slope surface. In areas such as open pit mining, where most slope surfaces are not planar, the importance of curvature becomes important due to the economic gains associated with creating a steeper slope. With advances in computing capabilities within the last decade, three-dimensional slope analysis can be performed within reasonable time frames. Some work has been done on the potential importance of curvature on slope stability, mainly assuming homogenous materials with a circular shear-failure mechanism. However, many open pit mines are excavated in jointed rock mass where a completely different set of failure mechanisms can be seen. Depending on the geometry and radius of the pit, the curved geometry may influence the factor of safety and failure behaviour compared to a two-dimensional slice.A series of numerical analyses were performed to investigate the effect of curvature on jointed rock slope stability compared to an equivalent two-dimensional slope analysis. By using discrete element method models, the influence of joint planes and interaction between distinct blocks can be seen. With a three-dimensional model, the effect of curvature can be combined with multiple joint sets at any orientation, which cannot be seen in a single slice. Numerous three-dimensional models are created, along with an equivalent unit-thick slice. The effect of curvature on a variety of different types of failure mechanisms is observed, and graphical relationships are created to quantify the difference between the three-dimensional factor of safety and the two-dimensional factor of safety based on the degree of curvature."

Jan 1, 2015

By Roger Potvin

Abstract The demand for pure zirconium and titanium metals in Germany increased considerably during the war. Pure zirconium was used in flash bulbs, in vacuum tubes, and in time fuses for bombs, where it has a decided advantage because it gives no gas in burning. Under the form of alloy, it was used with other rare elements for making substitutes for platinum; it was also used as a scavenging agent in high-grade steels. Metallic titanium was mainly used in connection with the manufacturing of special alloys. The authors were sent to Germany by the Department of Reconstruction and have investigated the German process developed for producing these rare metals. They describe the procedure and special equipment used for their commercial production in Germany during the war. General Metallic zirconium and titanium were .produced on a commercial scale in Germany by the thermal reduction, with metallic sodium, of potassium fluozirconate and titanium chloride, respectively, using a mixed potassium and sodium chloride flux. According to the information gathered, the sole German producer of these rare metals in pure form was the Deutsche Gold und Silber Scheideanstalt (commonly called Degussa), at their Werk II, 215 Gutleutstrasse, Frankfurt/Main, which was visited by the authors on September 18th, 1945. As far back as 1934, Degussa was carrying on active research on the manufacture of zirconium, and nearly one ton of the pure metal had been produced before September, 1939. Concurrently, a quite similar process was worked out for the recovery of titanium and it was in commercial operation in the year 1938, during which the production totalled about half a ton (metric). The demand, especially for pure zirconium, increased considerably during the war, attaining a total of about 48 tons during the period October, 1939, to the end of 1944, and reaching a peak of more than 15 tons in 1943. In 1944, the plant was slowed down due to the frequent and disastrous bombing by the Allies, especially in March and September.

Jan 1, 1946

By H. Perez, A. Lavoie, V. Prévost, P. Létourneau, P. Lind

The Home smelter is a custom copper smelter located in Rouyn-Noranda, Quebec. In 2005, the smelter produced 145,000 t of copper containing 807,000 oz of gold, 20,388,000 oz of silver in addition to 515,000 t of sulphuric acid. Recently, a flexible flow sheet has been developed incorporating the intermittent use of the Noranda Continuous Converter allowing for the increasing or decreasing of production based on market conditions, while attaining 90% or greater sulphur fixation regardless of operating mode. For 2006, the smelter is operating in full production mode and production is expected to be approximately 185,000 tm of copper. Mechanical modifications, process changes, metallurgical concepts, minor element treatments, and operational techniques that have allowed the smelter to develop this flexibility are presented. Current efforts to increase the productivity of the converter aisle and anode furnaces as well as improvements being made to address fugitive emissions are also discussed.

Jan 1, 2007

By D. F. Sangster, P. J. Hood, G. A. Gross

"Some results are presented of an integrated geological and geophysical study of Precambrian magnetite-quartz iron-formation in the Kapiko Iron Range north of Nakina, Ontario. Detailed geological and topographical mapping was carried out in conjunction with detailed geophysical investigations such as vertical magnetic field, vertical magnetic gradient, hammer seismic, horizontal-loop electromagnetic and magnetic susceptibility surveys. In addition, oriented drill cores were obtained for magnetic polarization studies.Vertical-force magnetic anomalies within individual rock units showed a strong positive correlation with topographic relief. Moreover, magnetic intensity was found not to be quantitatively proportional to the magnetite content in the rocks, due to the presence of high remanent magnetization of the magnetite. Also, the remanent polarization direction was sub parallel to the plunge of the fold structure and mineral lineation in associated rocks.Vertical magnetic gradient measurements were found to be more accurate in locating buried contacts between magnetite-quartz iron-formation and country rock than the vertical magnetic force data.An in-situ magnetic susceptibility meter was used to measure the magnetite content of iron-formation, and the measurements were subsequently compared with vertical-force magnetic results.The results of the EM survey were inconclusive; some magnetite-rich zones produced anomalies in the out-of-phase component. whereas others did not. The reasons for such inconsistencies are not yet apparent.Longitudinal seismic wave velocities measured parallel to the bedding in magnetite-quartz iron-formation ranged from 10,600 ft/sec. to 14,500 ft/sec. The seismic velocity appears to increase with an increase in deformation of the rocks."

Jan 1, 1966

By R. Chen, K. Xia

In deep mining activities, blasting induced compressive stress wave would be reflected as tensile wave at a free surface around the openings, which would facilitate the tensile failure of the deep rock since it is much weaker in tension than in compression. It is thus critical to understand the dynamic tensile failure of rocks subjected to static tension for deep rock engineering applications. A modified split Hopkinson pressure bar (SHPB) system is adopted to load Brazilian disc (BD) samples statically, and then exert dynamic load to the sample through stress wave generated by impact. The pulse shaper technique is used to generate a slowly rising stress wave and thus to facilitate the stress equilibrium of samples during each test. Five groups of Laurentian granite (with tensile strength of 12.8 MPa) BD samples under the pretension stress of 0 MPa, 2 MPa, 4 MPa, 8 MPa, and 10 MPa are tested under different loading rates. The result shows that the dynamic tensile strength of the rock decreases with the increase of pre-tension stress, which is easy to understand because pre-tension stress weakens the rock sample. It is also observed that under the same pre-tension stress, the dynamic tensile strength increases with the loading rate, revealing the so-called rate dependency that is common for engineering materials. Furthermore, it is found that the loading rate sensitivity of the rock increases with the increase of pre-tension stress. A qualitative explanation for this phenomenon is that more microcracks are generated and activated under higher pretension stress, resulting in a more viscous material. Based on the results, an empirical equation is proposed to fit the data and explain the dynamic tensile behaviour of rock under pre-tension stress. A physical model is used to simulate the dependency of the dynamic tensile strength of rock on the pre-tension stress and the loading rate, which is shown to be in good agreement with the experimental results.

Jan 1, 2015

By N. Razavinia

Most mining and metallurgical industries produce relatively large quantities of low grade waste heat which they vent, for the most part, to the environment. To date, little is being done to recover some of this heat and transform it from low grade to a high grade energy form such as electricity. A few decades back this was also true of paper, plastics and metals. Recycling was not a prominent activity. Today, we all know that it is and that recycling is a must for sustainable development. To this end, we feel that we are now at that point in time when the recycling of waste heat to electricity must be given serious consideration. By recycling waste heat one can achieve at least one if not two of the following benefits: 1) reduction in the carbon footprint ? by improving the overall energy efficiency of a process, and 2) production of electricity at an economically viable cost. We have developed a process that captures, concentrates and converts (3 C?s) waste heat to electricity. The process comprises 3 distinct interacting units. The first unit captures and concentrates waste heat using heat pipe technology. The second unit converts some of the concentrated heat to mechanical work which can then be readily converted to electricity. This unit is based on the classical piston/cylinder engine arrangement that is widely used by consumers to power systems with compressed air, for example. The third unit of the process dissipates the heat that the engine cannot convert to high grade energy. It also uses heat pipe technology to achieve this. The combination of the 3 units forms a unique system for recycling waste heat. This paper describes the system and it presents some results that show how the system can be made to be economically viable.

Aug 1, 2013

By Q. Li, X. -L. Lei

Accompanying global energy shortage and high energy prices, shale gas has been the focus of exploration and it has attracted great attention from both academia and industry. The combination of horizontal drilling and hydraulic fracturing enables the extraction of huge quantities of shale gas from impermeable shale formations. During the process of hydraulic fracturing, great amounts of water, sand and chemicals must be injected into the shale formation at a high pressure, which may trigger seismicity. Such events could occur due to the presence of faults or the reactivation of these potential faults. Shale is the main component of source rock in the Sichuan Basin, China, and has the greatest contribution to the natural gas of the basin. In order to investigate the fracturing mechanism of shale in the Sichuan Basin, China, a series of rock fracture tests under triaxial compression were carried out in the laboratory in order to investigate the hydraulic fracturing behavior in relation to the seismicity. Based on the high multichannel waveform recording system, the detailed spatio-temporal distribution of acoustic emission due to micro-cracking was used to examine the deformation and fracture behavior of shale. In addition, the effects of confining pressure on the deformation and fracture in shale under triaxial compression by acoustic emission monitoring and X-ray computed tomography were discussed in the paper. The experimental results indicate that the shale samples demonstrate brittle fracture behavior. The confining pressure has a great effect on the complexity of the fracture planes and the spatial distribution of acoustic emissions, but few contributions to the location of the major hydraulic fracturing plane. The foliation of shale plays a dominant role in the rupture process and the geometry of the major hydraulic fracturing plane. The high confining pressure increases the strength and restrains the deformation of shale during compression process. These results shed some light on the understanding of onset of hydraulic fracture initiation not only for shale gas exploration and production, but also for CO2 geological storage and underground energy storage.

Jan 1, 2015