Advanced Materials Research Vols. 361-363

Abstract: Expanded graphite (EG) was prepared by microwave irradiation at 1000 w for 60 s. It is a novel adsorbent for Pb (Ⅱ) adsorption. This paper aims to investigate the effect of the adsorption of EG. The adsorption behavior of Pb (Ⅱ) from aqueous solution onto EG was investigated with variety of parameters such as pH, adsorbents dosage, initial Pb (Ⅱ) concentration, contact time and temperature. On conditions that the pH=6.04,the dosage of adsorbent was 0.075g, the concentration of Pb(Ⅱ) was 100mg/L and the temperature was 15°C, the maximum removal rate could reach at 86.55% .The results showed that the EG was an efficient and novel adsorbent for the removal of lead from aqueous solution. The microstructures of the resultant expanded graphite were observed by scanning electron micrographs.

Abstract: Many factors may affect array induction log, including skin effect. In this paper, according to relative formula deduced, a correction method of skin effect based on multi-frequency measurement signals is proposed using only the real component. This paper gives apparent conductivities that are from first order derivative correction and second order derivative correction by Chebyshev polynomial fitting method. Compared with measured data calculation, it showed that the correction results from the method above were in good agreement with the data from Express software.

Abstract: In the case of Fourth Member of Quantou Formation (K₁q⁴) in Well X5-16 of Fuyu Oilfield, it integrates the theory of reservoir architecture and methodology for flow-unit analysis to characterize the architectural units and their permeable features in reservoirs. As the research found, point bars are very developed in low-sinuosity meandering distributary channels. Therefore, parameter modeling for reservoirs, confined by reservoir architecture is firstly constructed from empirical formulas and integrating the data from closely-spaced wells in dense pattern area. At this basis, clustering analysis with optimized reservoir parameters help demarcate the classification of flow units and further the Kriging interpolation method is introduced for interwell flow unit prediction. Besides, the study also illustrates the relationship between the lateral accretion and the flow unit. Finally, the research achievements were confirmed by successfully matching the production data, so as to predict how the remaining oil distributes, or to adjust the development plan, as well as enhance the oil recovery.

Abstract: With the help of the transmission line measure method of formation resistivity through casing, we have presented a calculated approach of potential distribution on the metal casing and in the fluid inside casing, realized the calculation of the resistivity logging response(RLR)of formation, and made inspection for two measure methods of formation resistivity. The numerical computing results show that the fluid in casing hardly has influence on the RLR of formation, but, when there are different kinds of fluids in casing, the interface of fluids has an obvious logging response for RLTA, and the response range of fluid interface is about the length of tool electrode spacing. The calculating examples also show that the measure and computation methods of formation resistivity for logging response have a larger effect when inside casing with fluid.

Abstract: Mechanisms of overpressure generation is key issue for fluid dynamics and hydrocarbon accumulation in sedimentary basin exploration. The contribution of aquathermal pressuring to overpressure generation is always focus problem. The equation of liquid state would describe internal relations of temperature, pressure and volume of pore fluid in thermodynamic system. The contribution ratio of overpressure generation by auqathermal pressuring and undercompaction based on equation of liquid state would obtain quantitative assessment of these two geological processes leading to generation of overpressure. The contribution ratio was expressed by function of formation porosity and temperature. The mechanism of overpressure generation of well ST36-1-1 was studied by this method, which developed overpressure in Qiongdongnan basin of northern South China Sea, research shows that contribution of overpressure generation from auqathermal pressuring is treble of undercompaction, and with increasing of formation porosity, contribution of auqathermal pressuring would increases gradually comparing with undercompaction

Abstract: Taking the Q area in Zhunger Basin for example, reservoirs and traps in the subwater fan in WuTonggou Formation can be identified by sequence stratigraphy, the analysis of seismic attributions and the optimization which can also be used to analyze the oil saturation. Therefore, the region of hydrocarbon can be predicted. The oil source rocks are in the middle of Permian System, and the major reservoirs are in the Upper Permian System. The WuTonggou Formation in upper Permian system can be divided into three parts: LST, TST and HST. Sand bodies of LST are the targets of this research. The subwater apron deposited from east to west. The braided channel in the middle fan is the best reservoir. The resolution was improved by the technology of seismic frequency division, and the strata slices of 40HZ seismic data were proved the best. Obviously, the subwater fan deposited from east and the braided channel changed its location continuously. The major flow direction of braided channel changed from the west to the south. It is also illustrated that the northern part of Q area uplifted and the sedimentary center migrated from northwest to southwest. The original sandstone was sealed by mudstone along with the transfer of braided channel. Therefore, the lithologic traps were updip pinch out, which can be generated because of the uplift of northern part. After the optimization of seismic attributes based on GA-BP, results showed that the areas of high oil saturation were in the west and southwest, especially the reservoirs which were in the southwest had the highest oil saturation.

Abstract: Unconventional natural gas because of a huge amount of resources has been received extensive attention in the world. Based on the present technology in China, tight sand gas as one type of unconventional gas, has become the most realistic energy resources, and has reached a certain development scale. Low porosity and permeability of tight sand gas reservoirs are widely distributed in China's major basins, the proved reserves of tight sand gas reservoirs in the proportion of reserves increases significantly year by year. Tight sand gas exploration in unconventional natural gas is most realistic, the concept of tight sand gas, reservoir characteristics, formation mechanism of unconventional tight sand gas, distribution in China are reviewed in the essay, exploration direction and some suggestions are pointed out at the end.

Abstract: This study was aimed at obtaining detailed information about the interaction of NaCl salinity and elevated atmospheric CO₂ concentration in the halophyte S.salsa, which was irrigated with five different salinity levels under ambient and elevated (530 ppm) CO₂. The results show that total soluble sugar concentration was significantly increased by salt-treatments in both leaves and roots, and that the most progressive sugar increments were observed in leaves and roots of S. salsa under the elevated CO₂. The Na+ concentration in the leaves and roots increased with the increased NaCl concentration, the K+ accumulation gradually decreaed by increasing salinity levels in leaves and roots. Proline increased in response to salt stress along with incremental NaCl concentration. The GB concentrations of leaves were significantly raised as NaCl levels increased. Electrolyte leakage increased in the leaves of S. salsa grown under NaCl stress. ψs of leaves and roots decreased as the NaCl concentration increase, and that elevated CO₂ both had markedly greater effects on ψs of leaves and roots. The osmotic adjustment values ascended with elevated CO₂ concentration in both leaves and roots.

Abstract: The mine prospecting has been entered into the key stage of “overcoming depth and finding blind” in our country at present. This article simulates the relationships between temperature, concentration and electrode potential by Nernst equation. And then, the characteristics of electrode trends and the influences to the deep mine resources prospecting using CSAMT are discussed. Finally, trends suppression by inversion correction method is studied combined LOTEM data. The results show that trends are produced in the electrode potential by the change of temperature and concentration. Trend noises display in two manners, relatively linear and nonlinear, and the spectrum of trends mainly focuses on or near the zero frequency. Positive trends lift the resistivity values of deep low resistivity object, and negative trends lower the resistivity values of deep high resistivity object, so the trends lead to wrong explanation results. Finally, the inversion correction method combined with LOTEM data can remove the trends successfully and is very important to the solution of mine crisis in our country.

Abstract: The abutment stress results from the load coming from overlying strata above the influence range of abutment stress and the load which coming from overlying strata above the stress shell passed by the shell. Through the mechanical calculation,this paper analyzed abutment stress distribution and fracture characteristics of coal seam resulted from the load of overlying strata passed by stress shell which exists in surrounding rock of working face, and obtained the laws of abutment stress distribution and fracture in coal seam in combination with numerical simulation and site testing. The characteristics of abutment stress distribution and fracture are related to the geometrical shape of the stress shell, such as height of the stress shell, horizontal distance between top of stress shell and coal wall,and width of stress shell skewback.