Advanced Materials Research Vol. 772

Abstract: Storage and transportation of natural gas with NGH method is a kind of novel technology developing rapidly at domestic and overseas currently. The stability and dissociation characteristic of hydrate at different temperature and pressure is a significant basis on its application and development. The existence of anomalous self-preservation effect indicates that gas hydrates have favorable stability in special low temperature range, and it provides theoretical and experimental basis for storage and transportation of natural gas with NGH method. The paper reviews study history and research development of hydrate self-preservation effect, and points out challenges for developing storage and transportation technology of natural gas with NGH.

Abstract: The stress-dependent permeability of ultra-low permeability rocks has a significant impact on the seepage. A number of experimental studies on the variation of permeability with stress change in low permeability reservoir have been done, but few are involved in ultra-low permeability cores. In this study, first, we fabricated the shear-stress microfracture cores and then the stress sensitive experiments were conducted. Second, a fracture deformation model was introduced in order to depict the stress sensitivity features of fracture media theoretically. Finally, a comparison of the theoretical curves with the experimental data had been done. The results show that the fabricated microfracture cores can be used in the permeability stress sensitive experiments. The permeability stress sensitive hysteresis of the microfracture cores is not obvious and the recovery degree of stress sensitive hysteresis is high in the unloading cycle for the grains were compacted in the process of shearing. The theoretical curves have the desired behavior which is consistent with the experimental data well. It indicates that the method of fabricating microfractures can similarly reveal the stress sensitivity features of the real microfracture ultralow permeability reservoir. This study do great benefit to reveal the stress sensitivity features of ultra-low permeability reservoir.

Abstract: As the sucker-rod pump placement depth increases, the load at the polished rod rises as well. Meanwhile, high load at the polished rod limits further increase of pump placement depth. This paper mainly analyses polished rod load on pumping system units and describes several methods to reduce beam pump load that are used in deep wells. On the basis of theoretical analyzing of three load reducing technologies such as application of compound fiberglass sucker rods, linear electric motors and rod load reducer, it was determined that using compound fiberglass rods in real practical cases shows obviously higher efficiency than other two. linear electric motors technology has advantages of being used in deep wells as well. Moreover rod load reducer shows good performance in deep wells, but because it does not possess energy conservation characteristic it may be uneconomic and less effective during production.

Abstract: Permeability cannot be directly predicted from porosity by using a single function in tight sandstones reservoirs due to the extreme heterogeneity. The hydraulic flow unit (HFU) approach and classification scale method (CSM) are available in permeability prediction, while they are all significant time-consuming. In this paper, based on the analysis of the proposed data sets of lab NMR experimental measurements by Xiao et al. (2012; 2013), the applicability of the classical SDR (Schlumberger Doll Research) and Timur-Coates models, which are used to estimate permeability from NMR logging is analyzed. A field example shows that the Timur-Coates model is valuable in tight sandstone permeability estimation once the involved input parameter of irreducible water saturation (S_wi) can be accurately calculated without acquiring T_2cutoff. While the SDR model is not available because the effects of hydrocarbon to NMR spectra cannot be removed.

Abstract: The storage tank plays a more and more important role in economic construction and the development. It always stores inflammable, explosive medium. The consequences are very serious, when the earthquake disaster occurs. In this paper, we build models of model tank and 20,000 m³ tanks with the finite element method, and analyze their seismic response between the former structure and the isolatied structure. We wish that the research can provide fundamental data for the similar studies.

Abstract: In this paper, the method and effect of logging curves wavelet transform in high-resolution sequence division are discussed, taking the middle oil sequence stratigraphic of DU-432 oil well in north-Songliao basin as an example. Using Wavelet Transform to GR logging curves, the relationship between logging curve signals and depth is transformed to the relationship between the depth and the scale domain, so that the wavelet curves in different scale are obtained. Then the relationship between the periodic oscillation characteristics of the wavelet curves under the best optimal scale factor and the sequence. Comparing the Sequence Stratigraphic Division by wavelet transform with the manual division, Results show that the Division by Sequence Stratigraphic wavelet transform is more objective and more effective and the Division provides a new way to high-resolution sequence stratigraphy.

Abstract: According to the Zhonghang construction project characteristics in Huidong county of Guangdong, the possible effects of pollution occurred in the development project construction period and the operation period have been respectively elaborated here. The dust occurred on construction period, waste water pollution of the operation period, and the adverse effects schemehis have been analyzed in the paper. Some concrete measurements for Zhonghang in satisfy human living project been put out.

Abstract: Thermal comfort problems experienced in buildings in warm humid climates has been a major concern for designers in the environmental design specialty especially in Nigeria and other developing countries. This paper through controlled experiments studies the effect of window shading on indoor comfort levels of buildings exposed to warm humid climates. Experimental model buildings with shaded and non-shaded windows were constructed for this purpose. Comfort data were obtained from the buildings and meteorological stations including comfort parametric ranges. The data were analyzed with statistical tools involving the central tendency and dispersion. Hypotheses were tested. Results showed that window shading has significant effect on the comfort level of buildings and consequently energy usage.

Abstract: In this paper, a Impulsive predator-prey system with Beddington-DeAngelis functional response is studied. By applying the comparison theorem of impulsive, sufficient conditions for the permanence of the system are obtained.

Abstract: Through the paleontology, lithology combination data,For Weihe basin Gushi hollow Tertiary the Zhangjiapo group unified hierarchical total divided into seven sections. According to coring, logging data to study the rock types and sedimentary structure,Summed up the logging of various sedimentary microfacies facies, clear in the study area is a shallow lake - a deeper lake - deep lake - deeper lake - shallow lake cyclic sedimentation.For single well facies analysis of typical wells in the region, the establishment of even well profile, determine the small layer of sedimentary facies the planar distribution concluded sedimentary facies model.