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91.
四川盆地南部中—上寒武统储层成岩作用 总被引:1,自引:0,他引:1
四川盆地南部中—上寒武统(洗象池群)储层为一套碳酸盐岩局限台地沉积,其岩性为粗粉晶—细晶白云岩、砾屑白云岩、砂屑白云岩、鲕粒白云岩等。成岩作用主要有压实作用、胶结作用、白云石化作用、岩溶作用、破裂作用等,白云石化作用和岩溶作用是形成优质储层的关键。白云石化的机理为混合水白云石化。岩溶作用具有多期性,包括沉积期岩溶、风化期岩溶、埋藏期古岩溶和褶皱期古岩溶等,以风化期岩溶为主。压实作用和胶结作用破坏了大量的原生孔隙和次生孔隙。压实作用主要发生在浅埋藏期,它与埋藏期胶结一同作用使孔隙度由原来的15%左右骤降至2%~3%左右。随着后来的岩溶作用和破裂作用等,部分储层的孔隙度又扩大到4%~5%左右,以晶间孔和晶间溶孔为主要储集空间类型。 相似文献
92.
93.
随着地形高差增大、地貌单元多变、近地表模型复杂,目前被广泛应用的初至折射静校正的精度已无法满足精细勘探的要求。初至层析静校正技术,由给定的初始模型进行正演,用射线追踪方法得到初始模型的初至波,利用该初至波和实际拾取的初至波进行比较,计算地表模型的修正量,反复迭代求得准确的地表模型。山西省国阳新能股份有限公司二矿390水平九采扩区地表标高940~1100m,地貌单元复杂,在对该区资料处理时,利用初至层析折射静校正,经9次迭代计算后,真实地刻划出近地表模型。在二种静校正技术对比中,初至折射静校正不但近地表模型精度低于层析折射静校正,而且其叠加剖面精细程度也远低于层析静校正,如在初至折射静校正叠加剖面同相轴上呈现的凹凸形态,在层析静校正叠加剖面并无显示,且后者剖面的信噪比也比前者明显提高。 相似文献
94.
An iterative inverse method, the sequential self-calibration method, is developed for mapping spatial distribution of a hydraulic
conductivity field by conditioning on nonreactive tracer breakthrough curves. A streamline-based, semi-analytical simulator
is adopted to simulate solute transport in a heterogeneous aquifer. The simulation is used as the forward modeling step. In
this study, the hydraulic conductivity is assumed to be a deterministic or random variable. Within the framework of the streamline-based
simulator, the efficient semi-analytical method is used to calculate sensitivity coefficients of the solute concentration
with respect to the hydraulic conductivity variation. The calculated sensitivities account for spatial correlations between
the solute concentration and parameters. The performance of the inverse method is assessed by two synthetic tracer tests conducted
in an aquifer with a distinct spatial pattern of heterogeneity. The study results indicate that the developed iterative inverse
method is able to identify and reproduce the large-scale heterogeneity pattern of the aquifer given appropriate observation
wells in these synthetic cases. 相似文献
95.
Based on four UK Schmidt Telescope (UKST) IIIa-j direct plates which had been digitized by the Automated Plate Measuring System (APM), a detailed identification of the disk galaxies in the Virgo cluster has been carried out. The certain and possible member galaxies are mainly selected from the updated Catalogue of 2096 Galaxies in the Virgo Cluster Area (VCC). The area of this identification covers a 85 square degree region centered on this cluster. As a result, we compiled a new catalogue of 340 certain and possible member disk galaxies, including 85 lenticulars (SO), 136 spirals (S) and 119 irregulars (Irr), where the APM-measured values of the position angle (P.A.) and diameters of 299 disk galaxies are provided. For at least 149 galaxies, the values of the P.A. and diameters are published for the first time.Comparison between the APM-measured P.A. and diameters of galaxies and those given by the Uppsala General Catalog of Galaxies (UGC) demonstrates the reliability of our data. The statistical properties and completeness of this database are also discussed. Compared with the UGC-given P.A. and diameters which were determined by eyes, our data has no selection effect owing to the instrument measurements. Within our searching region, this might be the largest and relatively complete photometric database published so far for investigating the spatial orientation of the spin vectors of galaxies in the Virgo cluster. 相似文献
96.
The survey for the HEIFE(Atmosphere-Land Surface Processes Experiment at Heihe River Basin,Western China) is given in the paper.The following basic subjects for land-surface processes in arid areas are studied:(1) the general characteristics of the energy budget on ground surface in arid areas;(2) the parameterization of the land surface processes;(3) the interaction between oasis and its desert circumstances,a special phenomenon in arid areas.The analysis shows that the sensible heat flux in the surface energy budget is in the majority,and the latent heat flux may be neglected.The influence of atmospheric stratification stability on the turbulent transfer of energy and substance must be considered in parameterization of land surface processes in arid areas.The "cold island effect" phenomenon in oasis and the "humidity inversion" phenomenon in desert near oasis are the result of the interaction between them.The results would improve the understanding of land surface processes in arid areas. 相似文献
97.
暖切变型江淮梅雨锋结构及其形成和维持机制 总被引:26,自引:6,他引:20
对在1991年7月上旬特别稳定的梅雨形势下持续10天的特大暴雨期作了合成和典型过程研究,并进一步探讨了暖切变型江淮梅雨锋天气系统模型。它在自由大气层表现为结构竖立的相当正压切变线和一种不同于经典地转动量近似的带状准二维运动场。边界层的浅层锋生倾斜环流以及偏于切变线轴以南的Ekman抽吸与自由大气层中基本上由积云对流加热驱动的竖直环流相互依存和耦合,造成持续的大暴雨。这种系统的初生和中断后复苏的机制可能是由斜压性极弱的副热带高空东移的短波扰动在低层“湿度锋”带紧南侧触发导致的一种带状CISK。 相似文献
98.
Summary A model of the polluted arctic troposphere is constructed to estimate the magnitude and seasonal variation of the climate forcing function of arctic haze. Using a pill-box bathtub model for the Arctic and envisioning it to be filled with pollution from industrial sources in Eurasia, we estimate that maximum climate perturbation from arctic contamination occurs in the spring months. The major perturbation to the radiation budget is a lowering of the albedo (heating) of the earth-atmosphere system around the vernal equinox and is due to a trace amount (about 5% by mass) of black carbon associated with the removal-resistant submicron mode of aerosols. The black carbon over the reflecting polar ice/snow introduces a heating of about 1.5 degree per day into the haze layer.With 8 Figures 相似文献
99.
100.
与中上地壳相比,对下地壳组成、结构的认识受限于样品的获取,然而天然火山作用携带的下地壳捕虏体可以为了解下地壳提供关键样品。华北克拉通是世界上最古老的克拉通之一,显生宙以来的火山作用携带有丰富的下地壳捕虏体,为探测华北下地壳组成、结构及其形成过程提供了可能。通过对这些捕虏体定深、定性及定年的综合研究,构建了以信阳,莒南,汉诺坝和女山等典型地区为代表的下地壳组成、结构剖面模型。这些剖面表明,华北克拉通下地壳具有分层的特点,且上老下新,暗示可能与底侵作用有关。其中捕虏体的锆石U- Pb年龄和Hf同位素的研究,揭示了该克拉通下地壳复杂的形成与演化过程:最古老的组成部分可能老至~4. 0 Ga冥古宙,此后经历了3. 80~3. 65 Ga古太古代的再造作用,2. 8~2. 5 Ga 新太古代和2. 3~1. 8 Ga 古元古代的增生与再造共存,同时还经历了显生宙以来包括462~220 Ma,140~90 Ma和47~45 Ma的增生与再造事件。 相似文献