Advanced Materials Research Vols. 962-965

Abstract: The Mo mineralization of the Kayizi deposit occurs in the edge of a granodiorite intrusion, and consists of two mineral belts, in which the biggest ore body is 400 m long and 140 m wide. The ore is dominated by disseminated and spot-like molybdenite, with its grade of 0.04%~1.53%, and some up to 10%~15%. The country rock alteration displays distinctive porphyry deposit alteration assemblages, including K-feldspathisation, pyrite-sericitization, and propylition. The petrochemical of the Mo-bearing granodiorites suggests the petrogenesis associated with subduction. The Re-Os model ages of 254.4±1.9 Ma, 257.0±3.4 Ma, and 258.5±2.0 Ma, yielded from three molybdenites, support that the mineralization occurred in the late Permian, whilst the deposit was tectonically in the late Paleozoic rift basin. Therefore, we considered in this paper that the Kayizi porphyry Mo deposit may have been formed as a result of the paleo Tethys subduction to the Tarim plate.

Abstract: Based on large scale geological mapping, geological-section, tectonic and geochemical studies on the carbonate-hosted Pb-Zn deposits in NE Yunnan, the metallogenic geological conditions are discussed, and the ore-prospecting indicators are summarized. The Pb-Zn deposits have many common features, which are mainly controlled by the thrust fault-fold structures and lithological conditions. The ore-forming mechanism of them is similar to the MVT Pb-Zn deposit. The combination of thrust fault-fold structures and altered carbonate rocks with geochemical anomalies are good indicators for prospecting.

Abstract: Xu 30 block is located in the southwest of Yushulin oil field, Putaohua reservoir is the main reservoir. Based on the analysis of the core information and well logging facies elements, and combining with the sedimentary characteristics of the study area, this paper discusses the types of sedimentary microfacies of Xu 30 block in Yushulin oil field in order to guide the future oil and gas exploration and development. The results show that the target layer in the study area having obvious characteristics of underwater distributary channel is delta front facies, and it can be divided into underwater distributary channel, seat body, sheet sand, the inner front sheet sand and the external delta front sedimentary microfacies. Further analysis of sedimentary characteristics, this paper establishes logging microfacies models and draws out 9 time units sedimentary microfacies in plane distribution diagrams. This study can offer not only an important geologic evidence for Putaohua reservoir at Xu 30 block, but also a basement for the distribution law of oil, water and the remaining oil.

Abstract: Daqing Oilfield has entered the high water cut development period, inter-plane layers, the inner layer of contradiction, multi-well, multi-layer high water, the remaining oil is highly fragmented. To mitigate the production decline, the need for sophisticated test stratified water injection technology, give full play to the advantages of each technology, and effective control of the natural decline rate and an average annual rate of increase water effectively tap the potential of residual oil. Use coring technology, rock pyrolysis technique, interpretation and evaluation method for logging flooded layer chromatography and saturated hydrocarbon fluorescence microscopy imaging technology created by the impact of a small reservoir heterogeneity can be intuitive, accurate evaluation of the remaining oil, applied sidewall coring data injection wells can profile, low oil shutoff and potential aquifer fracturing provide a strong basis.

Abstract: The southern and eastern Tibetan Plateau is very rich in the Geothermal resource, especailly in Yangbajain. To study the Geothermal in Yangbajain, a wide band magnetotelluric sounding profile, which belongs to the project “the process of the magnetotelluric sounding data in the Tibetan Plateau”, was finished in 2013. The line is from Zhanang to Yangbajain. The line is more than 200KM long and has 36 stations, and it crosses the Indus-Yarlung Zangbo Suture Zone (IYZSZ). The result shows that a large scale highly conductive body exists between the area of Zhanang and Yangbajain, which reaches more than 15KM in depth. It is proved that the highly conductive body suggests that partial melt and/or aqueous fluids are widespread within the Tibetan crust. Generally speaking, the existence of the large highly conductive body has a close relation with the underground thermal state. So we infer that the existence of a huge scale highly conductive body under Yangbajain means the active underground thermal movement which leads to the rich geothermal in Yangbajain.

Abstract: Large loop source TEM method has played an important role in minerals and engineering exploration. But there is a strong border effect when one explains by central loop later-time apparent resistivity. In this paper, a method was used to calculate all-time apparent resistivity by magnetic dipoles composing loop. For 1D forward data, all-time apparent resistivity was computed and compared with later-time apparent resistivity. Conclusions have been drawn that all-time apparent resistivity has no border effect on homogeneous ground model; but for complex layered model, all-time apparent resistivity border effect is reflected in vicinity of false extreme point of apparent resistivity curve, and is much weaker than later-time apparent resistivity border effect. The conclusions are conducive to a correct understanding of using all-time apparent resistivity to eliminate border effect and guide correct interpretation of measurement data.

Abstract: On the basis of the relevant identification theory of pseudo-random code signal, the signals of CSAMT are divided into three parts according to the frequency of the signal. The signals which are susceptible to 50Hz interference signal and its harmonic components should be set by pseudo-random code way. Others are set by single square waveform way. The Control and signal generation software of the transmitter system is built on the advanced virtual instrument platform, LabVIEW. The hardware of the transmitter system is mainly composed of host computer, data acquisition card, high-speed optocoupler, IGBT driver module and four IGBT switches. The data acquisition card generate PWM signals, the high-speed optocoupler isolates low-voltage part and high-voltage part. IGBT drive module and four IGBT switches constitute high-voltage part. Entire transmitter system is suitable for different environments and research tasks, the transmit frequency are adjustable, and the pseudo-random code signal has strong capability to suppress the interference signals. The control software on host computer is simple and clear. There is good prospect for the use.

Abstract: Based on the self-made triaxial servo-controlled seepage equipment for thermo-hydro-mechanical coupling of coal containing gas, the experimental study on the thickness effect of composite coal and rock containing gas was carried out with the length of composite coal and rocks, confining pressure and gas pressure fixed, meanwhile change the thickness of sandstones and coal. The results show that the strain-stress curve of composite coal and rock containing gas has great identity with the typical strain-stress curve of coal or rock. The thickness effect does exist in the composite coal and rock, different thickness ratios between sandstone on top and coal have different effect on the peak strength of composite coal and rocks. When the ratio of sandstone on top to coal is close to 1.1, the extremum of the peak strength will appear more easily in the condition of the same coal thickness. The strength of composite coal and rocks will fall if the ratio is higher or lower than the ratio of thickness correspondence of the extremum, moreover, the speed of decrease is higher when the sandstone is thinner than the coal. The peak strength of composite coal and rocks varies between the strength of coal and the sandstone. The elasticity modulus of the rock-coal-rock body varies between the coal and sandstone, moreover, an extremum appears more easily when the ratio of sandstone on top to coal is close to 1.1. The poisson's ratios of composite coal and rocks are lower than sandstone, higher than coals. The results have a reference value in the support of half coal crag tunnel and the mechanical features of the composite coal and rocks containing gas.

Abstract: In order to correctly rapidly predict the location of the sources of mine water influx, cluster analysis of the chemical characteristics of water is an effective adjunct way. To contrast hydrochemcial indexes of Mine inflow point and the points of water sampling and draw the A.M.Piper’s three line diagram and observe the area where they are, the location of the sources of mine water influx can be distinguished by analyzing the Similarity of the hydrochemcial indexes of Mine inflow point and the points of water sampling. The results show that the result of predicting the location of the sources of mine water influx through the above method shows high accuracy and has great reference value.

Abstract: It was very important to obtain the failure height of overlying strata to ensure safety mining under water body and protect surface and underground water resources. Aimed at the failure of overlying strata of 6204 full-mechanized mining in Ordos, the paper proposed a new detection method of the failure height of overlying strata, and verified the accuracy and practicability of this detection method by comparing with the traditional borehole TV observations.