Advanced Materials Research Vols. 807-809

Abstract: Provenance study is the most basic and important work to find out provenance location and quality, to ascertain sediment transporting way, and to confirm depositional system display in addition to sandstone. Shanxi Formation in Lower Permian has a depositional system distribution from North to South in Ordos Basin. The north provenance in Ordos is regarded as the leading factor to the facies, so it is relatively weaker about the south provenance. Now that all about provenance study in southwestern Basin has been a concern of explorationists, which is also the fundamental criterion of next aspect. This thesis analyses the main and subordinate provenances of Southwestern Ordos Basin in Shanxi Period according to sedimentary petrology (composition, heavy mineral assemblage, paleocurrent direction, cathodoluminescence etc.), as well as sandstone thickness, to forecast prospective reservoir.

Abstract: Some research on the wave propagation in random medium with Von Karman correlation has been developed in this paper. It focuses on the seismic record of circular disturbance in random medium with Von Karman autocorrelation function. Six different kinds of random medium become the background of the dielectric object. The study of the impact to the responds of the dielectric objects can be measured by applying the FDTD to random background medium model. The numerical results show that the random media make the most obvious effect when the scale of imhomogeneity is close to the wave length.

Abstract: Northeast China is in geotectonics transition period and forms a complicated sedimentary structure background in Carboniferous-Permian period. Northeast Area mentioned in this paper refers to the north of Xilamulun river-Changchun-Yanji line, where Carboniferous- Permian system spreads widely. Sedimentary facies and lithofacies paleogeography is studied to examine regional sedimentary structure background.

Abstract: This ore from Vietnam contains a lot of slime, disseminated extent of valuable mineral is fine, and the gold grade of raw ore is low; therefore, this ore is hard to concentrate. Through the study can be found that qualified indices are not able to be obtained through single gravity separation or single flotation. Based on the analysis of test data, and taking the nature of the ore into account, proposed a united process of gravity separation and flotation. The test results show that the process has achieved qualified results.

Abstract: Central Yunnan lead-zinc polymetallic province in Sichuan-Yunnan-Guizhou metallogenic province has 50 large, medium and small acale of pb-zn deposits. Through contrast research, ore-bearing rock is developed from Kunyang group of Early Proterozoic to Triassic carbonate, ore body, which is characterized by low temperature and low salinity, is obviously controlled by faults, and is accompanied by a strong dolomitization and calciization. Possiblly, metallogenic epoch is Mesozonic. The ore-forming material mainly comes from strata itself, lesser from magmatic rocks. Underground thermal water is the main mineralized hydrothermal water.

Abstract: The Lishui sag located at Southwest of the East China Sea Shelf Basin. It had undergone the four stages of syn-rift processes in Late Cretaceous to Paleocene: initial rift stage, main rift stage, stable rift stage and decline stage. The tectonic evolution has control effect on the development of sequence stratigraphy and the sediments distribution. Three second-order sequences, five third-order sequences and twelve system tracts are distinguished. Different sedimentary facies recognized in the Lishui sag.

Abstract: Shale gas reservoir characterizes source bed being its bearing reservoir, no gaswater interface, low porosity and low permeability. So the exploration and production procedure of shale gas is much different from traditional gas. How to detect the gas content of the shale formation is the key problem to exploit the shale gas. An algorithm to calculate seismic signal spectrum indicated the decay of high frequency is proposed. This algorithm adopt matching pursuit spectrum decomposing method to do high accuracy time frequency analysis on seismic data under the condition that the nonhomogeneity size of geologic body is not much larger than the wavelength of seismic wave and the seismic data is processed with high resolution amplitude maintained method. Do geostatistic analysis on energy ratio of the objective interval which gets from the frequency spectrum of the interval. Then the distribution character of shale gas in the shale reservoir can be got. This technique is an effective geophysical method to identify and evaluate the shale gas reservoir. It can provide critical parameters to explore and develop shale gas. Gas content detection gets effective result by using this technique in Block PengShui of Sichuan Basin.

Abstract: Dissolution plays a dominant controlling role on reservoir properties in delta sandstone of the Permian He 8 Formation, Sulige gasfield. Dissolution forms intergranular dissolved pore and intragranular dissolved pore. Areas with high percentages of dissolved pores occur along delta-plain distributary channel and delta-front underwater distributary channel deposits. Due to dissolution, the porosity increased to 10-17% with permeability as high as 10md. Wells drilled through He 8 sandstones have high daily gas production of 4~6×10⁴m³/d.

Abstract: The research of structural-deformed coal is important in coalbed methane exploitation. Compared with those of undeformed coals, the geophysical logging characteristics of structural-deformed coals show lower amplitude value of deep lateral log (LLD) and density log (RHOB) and higher amplitude value of acoustic log (AC). In the southern Shizhuang Block, the structural-deformed coal is commonly developed, with the thickness ranging from 0.6 to 1.1 m. The thickness of structural-deformed coals accounts for 11.5-18.5% of the total coal thickness. In general, the structural-deformed coals are more developed in the west than those in the east of the study area.

Abstract: Orefield structures of Fankou lead-zinc deposit in Guangdong province is complex and have been argued about for years. On the basis of the theory and method of the geomechanics, the mechanics features of structural planes of the structures of Fankou lead-zinc orefield have been identified. Its indicated that its structure is divided into three types of systems, that is, the northwest trending structural belt which origin from the Caledonian stage to the Hercynian stage, the Lambda-type structure which origin from the Indo-Chinese stage to the Yanshan stage and the eastweat trending structural belt which origin the Himalayan stage. The lambda-type structure made of major fault of F₂₀₃ of strike northwest and branch fault of F₃, F₄ of strike northnortheast is identified as the structural system of mineralization.