Advanced Materials Research Vols. 734-737

Abstract: Considering variation of bearing capacity of foundation caused by crushing of coral sands, the variation of wind resistance reliability of foundation in coral sands was studied. Based on the use of exponential decay model of bearing capacity of foundation, the reliability index of foundation at different time was calculated. Calculation shows that in the mid-term of foundations life in coral sands, attention should be paid to the assessment of wind resistance reliability of foundation, and it is necessary to track the variation of wind resistance performance of foundation in time. After a long time of operation, assessment must be applied to the wind resistance reliability of foundation combining with inspection.

Abstract: Through the hydrous pyrolysis experiments of coal-measure source rocks in Taiyuan formation in Ordos Basin with different mediums from 250 °C to 550 °C, with a stepwise heating stage of 50 °C, the characteristics of gas and liquid products are discussed systematically in this paper. The results show that the change rule of hydrocarbon productivity of coal with temperature is similar to mudstone. Total hydrocarbon productivity and gas hydrocarbon productivity increase with temperature rise. Liquid hydrocarbon productivity increases with temperature rise first and then decreases. The peak yield of oil of coal appears at the heating temperature 350 °C, mudstone at 375 °C. The peak yield of mudstone lags behind. The non-hydrocarbon gas productivity increases with temperature rise. The non-hydrocarbon gases are carbon dioxide, nitrogen gas and oxygen mainly. The productivity of carbon dioxide is significantly higher than other non-hydrocarbon gas productivities. The main hydrocarbon gas is methane. The productivity of methane increases when temperature rises. And the productivity increases obviously after 400 °C.

Abstract: 3D GIS is a useful modeling tool, which can greatly improve the efficiency and accuracy of the geological modeling, meet the requirements of modeling in complicated geological area. A typical 3D geological model is composed of one or a plurality of stratum, structure, fault etc. In this paper, we divide geological body into blocks, determinate each levels block boundary, build single block model, couple them up in 3D space. Combining with variation characteristics of 3D geological body, by manual interpretation or second derivative method, we get their distribution characteristics of fault unconfirmed by drilling. Through 3D GIS visualization and space analysis, we can not only be facilitate to manage drilling data and visualize underground geological body, but also analyze fault characteristics from a real angle, confirm their boundary, get ore body distribution characteristics, and provide credible digital model for ore grade analysis.

Abstract: In coalfield geological exploration, in the face of complexity and levity of geological bodies, the reservoir geological modeling technique a new and high technique grown up in recent years, plays an important role on exploration and development of CBM. Reservoir modeling would be finished through 3 stages: reservoir structure modeling, precipitation facies modeling, reservoir properties modeling. A 3D geological model may carry out the meticulous description of coal reservoir , and quantitatively characterize the inhomogeneities of reservoir. In addition, geological modeling is of great importance to engineering design and construction as well as information management, analysis and decision making.

Abstract: Luziyuan Pb-Zn-Fe polymetallic ore deposit is a large-size ore deposit. Its ore minerals were systematically studied on thin section and polished section microscope observation for the first time in this paper. The results show that the main metal sulfides include sphalerite, galena, chalcopyrite and pyrite. According to the geological features,mineral characteristics and penetration relationship of minerals,the metallogenic can be divided into four stages: primary sedimentary stage, sedimentary metamorphism stage, hydrothermal stage and oxidation stage. The deposit is a superimposed deposit associated with magma and hydrothermal caused by buried rock bodies during Yanshannian.

Abstract: The lead-zinc ore in Luziyuan, Zhenkang Town, Yunnan Province is a large lead-zinc polymetallic deposit discovered in recent years. The ore body mainly occurs in the stratum of Shahechang Group of Upper Cambrian. Controlled by NE trending faults and its flanking associated structures, it features equal interval and lateral trending distribution in the spatial domain. The development and mineralization of wall-rock alteration experienced two stages, low medium temperature stage and medium-high temperature stage. Metallogenic materials are mainly from the ore-bearing stratum and deep concealed rock mass. Through the study of such geological features as lithology of ore-bearing stratum, structure of ore-controlling Faults, wall-rock alteration, and ore fabrics, the author believes that the formation of the deposit is closely related to the multi stages of tectonic movements and magmatic hydrothermal activities. It is a sedimentary-reworked type, and skarn-type lead-zinc-iron polymetallic deposit and it is of multiple mineralization stages and varieties of mineral sources.

Abstract: Copper consumption is the largest and the most important metal mineral resources during the process of industrialization, urbanization. This paper analyzes the reserves distribution of the global copper resources, global copper resource investment and development zone, and global mining copper demand increment and its capacity increment trend, showing that, (1) over the next 20 years the global iron and aluminum resource supply relatively loose, copper resources supply pressure is bigger; (2) Global copper resources are relatively scarce, the distribution, Chile, Peru and Australia among the three countries accounted for 53% of global reserves; (3) Along with the growth of the asean and India resource requirements, Africa, southeast Asia and central Asia will become the important resource of supply. (4) Since the 20th century, along with the global demand for resources at the center of transfer to North America, Asia Pacific (Europe), Europe, North America, South America, Australia and southeast Asia, in turn, become the important resource of supply

Abstract: A rapid method for 3D physical properties inversion based on separation and continuation of potential field are introduced in this paper. The inversion technique characterized by faster computing speed, it does not need to divide the underground field sources region into many rectangular blocks in one time and does not need to solve linear algebraic equations as well. So, this technique can overcome the requirement of large computer memory, unstable solution and computation time bottleneck which hinders the application of 3D inversion to practice. The method is used to apparent magnetic susceptibility inversion of magnetic anomaly in a iron mine area, the inversion results show that the method has good accuracy, and the advantages of strong stability and a high computation speed, and is suitable for 3D inversion of magnetic data in large area.

Abstract: It’s a great challenge in identifying gas bearing formation from conventional logs in tight gas sandstones due to the low resistivity contrast caused by high irreducible water saturation. Based on the difference of the principles of three kinds of porosity logs (density, neutron and acoustic logs), three porosities difference method, three porosities ratio method, correlation of neutron and density logs and the overlap method of water-filled porosity and total porosity are introduced to identify tight gas bearing reservoirs. In gas bearing formations, the difference of three porosities is higher than 0.0, the ratio of three porosities is higher than 1.0, the correlation between density and neutron logs is negative, and the water filled porosities are lower than total porosities. On the contrary, in water saturated formations, the difference of three porosities is lower than 0.0, the ratio of three porosities is lower than 1.0, the correlation between density and neutron logs is positive, and the water filled porosities are overlapped with total porosities. Considering the complexity of in-suit formation, when the proposed identification criterion are mainly meet, the pore fluid should be determined, field examples show that the proposed techniques are applicable in tight gas formation identification.