The SPE has split the former "Management & Information" technical discipline into two new technical discplines:
- Data Science & Engineering Analytics
The SPE has split the former "Management & Information" technical discipline into two new technical discplines:
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Liu, Huajie (Shandong Key Laboratory of Oilfield Chemistry, Key Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education / School of Petroleum Engineering, China University of Petroleum (East China)) | Huo, Meihua (Shandong Key Laboratory of Oilfield Chemistry, Key Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education / School of Petroleum Engineering, China University of Petroleum (East China)) | Bu, Yuhuan (Shandong Key Laboratory of Oilfield Chemistry, Key Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education / School of Petroleum Engineering, China University of Petroleum (East China)) | Ma, Rui (Shandong Key Laboratory of Oilfield Chemistry, Key Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education / School of Petroleum Engineering, China University of Petroleum (East China))
ABSTRACT Gas hydrate dissociation would damage the cementing quality seriously due to the hydration exothermic of cement slurry. Therefore, the well cement slurry with low hydration exothermic is necessary. The design of well cement slurry with low hydration heat mainly includes three steps. First, high-strength metakaolin-based hollow-core microspheres (HMHM) were prepared. Second, phase change materials (PCM) was applied for encapsulating HMHM to form energy storage microsphere (ESM). Finally, the hydration heat of well cement with different dosage of ESM were tested, and the strength, rheological property, sedimentation stability and other basic properties were also evaluated. INTRODUCTION Hydrate reservoirs with high pressure and low temperature are distributed in offshore deep-water areas (Ravi, 1999; Armstrong, 2002). In the process of deep-water cementing, the temperature around the wellbore increases due to the heat release of cement slurry hydration, which destroys the stability of natural gas hydrate (Wang, 2019). The decomposition of natural gas hydrate will seriously damage the cementing quality (Xu, 2005). Paraffin is a phase change materials, which can effectively reduce the hydration heat release of cement, but paraffin can not be directly added to cement. Therefore, HMHM were introduced as new energy storage microspheres to carry PCM to avoid its directcontact with the cement slurry. EXPERIMENTAL Materials The hollow microspheres were prepared by inverse suspension polymerization, which regarded metakaolin as raw material and regarded alkali solution as activator. Metakaolin was provided by Yukun Mineral Company, Jiaozuo, China. Sodium hydroxide and sodium silicate were provided by Xilong Science and Technology Co. Ltd. and Guangzhou Julan Chemical Co. Ltd. PCM-30 (variation range of phase transition temperature: 15-40 °C) is a thermally stable and reliable oily hydrocarbon (No degradation occurring below 100 °C and continuous melting and freezing cycle shown), which has high phase transformation latent heat storage capacity (189 J / g). Its latent heat and temperature remain unchanged after multiple endothermic and exothermic processes, and there is no phase separation and corrosivity. Waterborne bisphenol A epoxy resin (ER) and waterborne polyamine epoxy curing agent are produced by Shanghai Hanzhong Coatings Co. Ltd., China. Class G oil well cement (600 mesh) is produced by Sichuan Jiahua Special Cement Co. Ltd. The specific surface area of Class G oil well cement is 332 m / kg, and the density of cement powder is 3.1g/m. Micro silicon (1000 mesh) was provided by Po Ken International Trading Company, Shandong province, China, and floating beads (6000 mesh) from Maanshan Institute of Mining Research, Anhui province, China. Fluid loss additive (polycarboxylic acids) and dispersant (sulfonated aldehydes and ketones) were provided by BO-XING engineering science and technology company of CNPC, Tianjin, China.
Lu, Jun (School of Energy Resources, China University of Geosciences, China-Beijing) | Wang, Yun (School of Geophysics and Information Technology, China-Beijing) | Shi, Ying (School of Energy Resources, China University of Geosciences, China-Beijing) | Yang, Zhen (School of Energy Resources, China University of Geosciences, China-Beijing)
ABSTRACT A three-dimensional (3D) three-component (3C) seismic exploration was conducted in the Huainan coalfield of North China. Because of the stress in different directions, the coal measure strata exhibit orthotropic anisotropy. Accordingly, the influence of VTI and HTI should be taken into account in the seismic data processing. In this paper, several key vector processing techniques which can retain the vector fidelity of valid seismic signals are discussed and illustrated. Presentation Date: Tuesday, October 16, 2018 Start Time: 1:50:00 PM Location: Poster Station 17 Presentation Type: Poster
Kulatilake, P. H. S. W. (University of Arizona) | Shreedharan, S. (University of Arizona) | Huang, G. (University of Arizona) | Cai, S. (University of Science and Technology) | Song, H. (University of Science and Technology)
Abstract: An underground iron mine in China has been used as a case-study to research the subsidence due to ore extraction and backfilling during open stoping operations. A 3-D discontinuum numerical model was built to scale incorporating geologic complexities including faults and interfaces between different lithologies, and the stoping and backfilling sequence adopted from the mine plans. The stoping was carried out in two vertically stacked horizontal layers, with a total of 16 stopes. Large displacements of up to 50 cm were observed along the roof of the stopes, and a maximum surface subsidence of 22.5 cm was observed at the surface. Backfilling was found to eliminate subsequent deformation and subsidence from occurring. The extraction of the upper orebody was found to influence deformations in the lower orebody. Finally, a subsidence profile was constructed to show the subsidence at all locations along the length of the surface and region of influence on the surface. Introduction Surface subsidence is a significant problem affecting infrastructure, settlements and forests over underground workings. In this paper, a discussion on ore extraction, backfilling operations and the consequential surface subsidence is presented considering the case study of the Luohe mine in China. Luohe is an underground pyrite holding of the Magang Steel Company in the Anhui province of China. The 250 m thick orebody lies at a depth of 400 m (Magang, 2012a), under a significant number of surface infrastructure (Fig. 1) which need to be protected from any adverse consequences of mining the iron deposits. To limit the subsidence, the mine has adopted backfilling operations post extraction in all stopes. In this paper, a section of the unmined orebody is considered and analyses have been performed to predict the amount of subsidence that the region is likely to undergo due to the extraction methodology being currently adopted in the mine. Because this study has attempted in incorporating the effect of in-situ stresses in the region, fault network, rock mass mechanical properties, interface features and backfilling operations on the subsidence, the discrete element method has been selected to carry out the analyses.
Yang, Ke (Anhui University of Science and Technology, Chongqing University, Huainan Mining Industry Group Co., LTD) | Xie, Guangxiang (Anhui University of Science and Technology)
A BSTRACT: In order to investigate into mechanical characteristics of rock surrounding entry with using bolt support system technology to control rock stability in large dip coal seams (LDCS) whose obliquity are from 25° to 45°, self-design rotatable experimental frame of similar material simulation was used to build the 30° model of solid-side entry based on analyzing geological and technological conditions in Huainan coal mines. Excavating and mining induced stress development, deformation characteristics, and breakage modes of rock surrounding gateway in LDCS have been synthetically analyzed. Results show that, influenced by large dip, asymmetrical characteristic of stress redistribution and deformation is to be serious and strata behaviors, such as roof falling and breaking, high-rib heaving and caving, floor heaving, and low-rib collapsing etc., are to be shrewd. All above utmost extent lead it is more difficultly to implement bolt support to control gateway rock stability in LDCSs mining. The high-rib and roof of entry in solid coal are the key sections to control in bolt support implementing. Effecting and Acting mechanism by large dip on mechanical characteristics of surrounding rock and bolt support system are opened. And it is also very important to improve support material, optimize support parameters, and enhance excavating management. 1. INTRODUCTION Coal seam obliquity increasing results in asymmetrical structure of extracting roadway and adds it is difficult to control rock stability while bolt support system is implemented, which limits safely and high-efficiently mining LDCS whose obliquity is from 25° to 45°.Simulation material physical experiment has been an important method and usually used to investigate into deformation, failure, and extracting-induced & mining-induced stress redistribution of rock. Also, the method has been applied to study mechanical characteristics of rock surrounding roadway with bolt support system and played active roles in mining engineering [1-10].
On July 6, 2009, the world first commercial single compressed natural gas (CNG) fueled ship, M.V. NP Jenjosh, which is first one of 12 contracted vessels built in Dajiang and Hongyu shipyards located in Wuhu city of Anhui Province, P.R. China and classed to China Classification Society (CCS), is delivered to the owner, Jenjosh Group based in Thailand. This paper will make some technical discussions during the class plans review of the subject vessels, including: hull technical practices, machinery & electrical technical practices and also make some discussions on the designing the similar CNG fueled ships and developing the international gas fueled (IGF) ship code in future. In the final, this paper has made conclusions and looked forward to the future practice of the CNG fueled ship.
On July 6, 2009, the world's first commercial single compressed natural gas (CNG) fueled ship, M.V. NP Jenjosh—the first of 12 contracted vessels built in Dajiang and Hongyu shipyards located in Wuhu city of Anhui Province, P.R. China and classed to China Classification Society (CCS)—was delivered to the owner, Jenjosh Group based in Thailand. This paper contains some technical discussions that took place during the class plan review of the subject vessels, including: hull technical practices, machinery, and electrical technical practices, and also discusses designing the similar CNG fueled ships and developing the international gas-fueled (IGF) ship code in future. Finally, this paper draws conclusions and looks forward to the future practice of the CNG fueled ship.
Yang, Ke (Key Laboratory of Coal Mine Safety and Efficiently Caving of Ministry of Education, Anhui University of Science and Technology, Key Laboratory of Integrated Coal Exploitation and Gas Extraction, Anhui University of Science and Technology)
ABSTRACT: A key issue in deep underground mining is to understand and master the evolving patterns of mining-induced stress, and to control and utilize the action of rock pressure, especially for designing safe and economic coal pillar widths. Different coal pillar widths result in differences in deformation, stress and movement of rocks surrounding the gateway and strongly influence the stability and maintenance of the gateway. Based on numerical simulation, the characteristics of deformation, stress and movement of rocks surrounding gateway and the stability of gateway was synthetically investigated. The results show that the stress distribution and deformation characteristics of surrounding rock vary with different pillar widths during caving. Stress distribution in the coal pillars and changes with different pillar widths. The allowable deformation and stability of the opening are based on the stress distribution and developing a critical stress-width relationship. 1. INTRODUCTION Based on the 3-D stress fields of working face and surrounding rocks, the changing of coal pillar width results in not only the mechanic state of coal pillar changing but also the mechanic field of coal entity besides of pillar changing. The changing laws certainly will influence the stability of gateway [1~13]. FLAC3D is widely applied in simulating and computing geological materials and rock-soil engineering with nonlinear, bigdeformation and instability mechanic actions, especially in plastic flow after yield and gradual breaking and falling[5,6]. So the surrounding rocks fracturing and stress fields of gateway are simulated and analyzed with FLAC3D in different wide pillars and surrounding rocks stability of gateway influenced different coal pillar widths is discussed. 2. GEOLOGICAL AND MINING TECHNICAL CONDITIONS OF WORKING FACE The length on the strike is 1674m and to the dip is 231.8m, the ground level is +20.4~+25.8m and the face level is -588~-662m of the No. 1151 (3) fully mechanized top-coal caving (FMTC) mining face in Xieqiao Mine. The coal seam texture is steady, the average thickness of coal seam is 5.4m, the average obliquity is 13°, the ratio of caving height and top coal height is 1:1~1.08. The conditions of seam roof and floor are: main roof is powder and thin sandstone, thickness is 6.2m; immediate roof is slob or arenaceous slob and C13-2, thickness is 3.26m; immediate floor is slob, thickness is 1.5m; main floor is powder sandstone, thickness is 2.8m. 3. SIMULATION MODEL In order to estimating rocks breaking, reflecting remains strength gradually reducing during deforming and gob rock-debris perdurable bulk contractility and strain induration, the Mohr-coulomb yield criterion(Eq. (1)), strain-intenerate model and bulk-induration are respectively applied. According to the geological conditions, the model's length, width and height are 500m, 600m and 314.17m and the model has 95332 3-D cells and 112739 crunodes (Fig. 1). Sides and floor of model are limited horizontal moving and vertical moving, and top of model are applied vertical load to simulating overlay rocks weight (sz=-12.56MPa). The breaking and stress of surrounding rocks are simulated with 3m, 5m, 7m, 10m, 15m and 20m widths.
Qinyong, Ma (Department of Civil Engineering, Anhui University of Science and Technology) | Meifeng, Cai (School of Civil and Environmental Engineering, University of Science and Technology of Beijing) | Shisheng, Hu (Department of Mechanics and Engineering, University of Science and Technology of china) | Baisheng, Chen (Department of Mechanics and Engineering, University of Science and Technology of china)
ABSTRACT The Split Hopkinson Pressure Bar tests of frozen clay are carried through at −5°C, −7°C, −10°C, −12°C, 15°C, −17°C and −20°C at four different strain rates of 300/s, 600/s, 1050/s and 1450/s. The experimental analyses show that flow stress of dynamic stress-strain curves increases with increasing strain rates at the same temperature, but when the strain rates goes up to a certain value, flow stress decreases with increasing strain rates. The different dynamic stress-strain curves of the same strain rate at different temperatures are converged. The higher the strain rate is, the more obviously the curves are converged. Test results indicate that the dynamic stress-strain curves oscillate obviously. And the oscillation becomes more obvious with the decreasing temperature and rising strain rate. 1 EXPERIMENTAL PRINCIPLE The high-pressure air pushes bullet with a certain speed to impact the input bar, and the input bar creates a stress wave in the input bar. When the stress wave reached the specimen, it reflects many times between the input bar-specimen interface and the output bar-specimen interface. Stress of specimen increases rapidly and tends to be uniform. During the test, the two bars are always at elastic state. So the average stress, average strain and strain rate can be obtained respectively through the waveform recorded by strain gauges, which were pasted on the two bars. Then the relationships among stress, strain and strain rate of frozen soil can be obtained. Where, σ I (t), σ R (t), σ T (t)—amplitude of incident wave, reflection wave and transmitted wave; A, A0 —cross section of the specimen and the elastic bar; ρ —density of the elastic bar; c p —the propagation speed of elastic wave in the bar; L m —the length of specimen. Figure 1. Schematic of the SHPB (_ 37 mm) system used for frozen clay test. 2 EXPERIMENTAL METHOD The device for impact compression experiment is split Hopkinson pressure bar of _ 37 mm(figure 1). The wave impedance of frozen soil is very low. The pressure bar is made of aluminum, and the lengths of impact bars are 800mm and 400 mm, respectively. The samples were got from a certain shaft in Anhui Province. The dry density is 1710 kg/m3, and water content is 21.42%. The specimens are 33.5mmin diameter and 18.2mmin thickness (figure 2). Data of input waves and output waves is obtained by measuring technique of strain gauge.
ABSTRACT ABSTRACT: Acoustic wave detection technique has been developed for over 30 years, whereas the study on the relation between acoustic wave speed and the mechanical characteristics of rock is just on its inception. Based on the geographical conditions of the Pansan coal mine of the Huinan coalfield and using analogical simulation experiments and numerical simulation technique, this paper carries out a research on the speed characteristics and their influence factors of the acoustic wave of facies transition rock mass. It is concluded that the stress distribution in the rock mass changes due to the existence of facies transition mass in the rock mass. In general, the upper part of the facies transition mass is stress-bearing area, and the tip parts are stress-concentration area. The existence of the facies transition mass also leads to the new speed distribution of acoustic wave in the model. The speed of the upper part of the facies transition mass is higher than that of the lower part of them. Its interior, however, usually has a low acoustic wave speed. The acoustic wave, after penetrating through the facies transition medium, gets its speed lowered due to the action of the facies transition mass. The study is significant to the acoustic wave detection in underground engineering and the seismic prospecting on the subtle geological structures. INTRODUCTION Acoustic wave detection technique is a new method developed in the last 30 years, which is convenient, fast, reliable, economical and non-damageable. Thus it has been widely applied in fields of geotechnical engineering. Currently it is successfully used to determine the elastic parameters of soil and rock samples, and simple model testing of the rock mass . However, some problems remain unsolved, such as the relations between the acoustic characteristics of the rock and rock mass, and their structures and stress status, as well as the loading and unloading procedures. These problems make it difficult for the acoustic wave detection to solve complicated situations such as the relation between acoustic wave and the mechanical characteristics of the rock. These retard further use of acoustic wave detection technique into the field of geotechnology engineering. The coal measures in the Huainan coalfield were formed in a delta plain. The coal seam #13-1, together with the roof and floor strata, were formed in late Permian Age in a network stream channel deposition system of a delta plain caused by a river with multi-continental sources. The roof rock strata mainly comprises of mudstone, silty mudstone, siltstone and fine sandstone. The horizontal surfaces bear the shapes of ribbons and reticula, while the profiles present the shapes of lenses. The lithologic and petrographic changes occur cyclically in perpendicular directions, and the sediment layers are either thicker, thinner, bifurcated, or pinched out in the horizontal direction.[2-7](Figures 1 and 2). The speed characteristics of the acoustic wave of sedimentary facies transition rock mass are analyzed. Sedimentary facies transition rock mass is commonly existed in the strata and has special characteristics. The drastic decrease of sedimentary sand mass helps to form inconsecutive rock mass.
ABSTRACT ABSTRACT: Being based on sedimentary rocks of coal measures, this paper systematically analyses mechanical properties of sedimentary rocks and their influencing factors such as confining pressure, temperature and the content of water by using triaxial mechanical tests. The mechanical behaviours of different lithological rocks under different confining pressures, temperatures and moistures have been studied. As a result the qualitative and quantitative relationships between the mechanical properties of sedimentary rocks of coal measures and confining pressure, temperature, and moisture are respectively established. It is shown that sedimentary rocks of coal measures are commonly weak, and the strength and stiffness of the rocks reduce rapidly from sandstone to mudstone. The stiffness and strength of different rocks increase with the increase of confining pressures. Behaviour of the strain softening and failure mechanism on different rocks transforms with the increase of confining pressures. Temperatures and moistures mainly influence the mechanical properties of rocks. Under the circumstance of dryness, low moisture and/or low temperature, the rocks demonstrate attributes of brittle and shear fracture after the peak strength. From the stress?strain curves the strain softening characters is obviously shown. With the increases of temperature and/or moisture, the values of the uniaxial compression strength and elastic modulus of the rocks decrease remarkably. In case plastic failure is dominant, however, the properties of strain softening is not so remarkable. INTRODUCTION Coal measures are the system of sedimentary rocks that have an intergrowth relationship based on alike genesis and being contained coal seam. Paleogeographical environment, paleo-tectonic condition, paleoclimate and paleo-plant condition are important controlling factors of the formation of coal measures. The formation of coal-bearing is the result of fillings at the edge of sedimentary basin under the condition of tropical climate, which is mainly composed of terrigenous detrital rocks and coal seam. Sedimentary rocks of coal measures are mainly sandstones, siltstones, sandy mudstones and mudstones. For example, coal measures of Permian period in Huainan coalfield of China were formed from delta plain environment . It contains 33.66% of sandstones, 8.7% of siltstone, 50.38% mudstone and 7.23% of coal seam. Sedimentary rocks of coal measures occur within the shallow crust and their formation and geological environment are distinctly different from magmatic rocks or metamorphic rocks. Because of their relatively weak lithological character, and their complex component and variation within wide limits, coal measures rocks show particular mechanical properties. Hence, when the rock quality and stability of rock slope and mining engineering are evaluated, it is necessary to study the mechanical properties of sedimentary rocks of coal measures and their control factors .