Calculation of the contribution of single-zone production by ultraviolet spectrum technique： A case study in well QHD32-6-3 field

Based on the established mathematic model and graphic interpretation, a new method, which is used to calculate the contribution of single-zone production in a commingled producing well by the ultraviolet spectrum technique, has been established. The standard plate was drawn using the extinction coefficient E of sample oils formulated artificially as y-axis and the wavelength as x-axis. The curve resulting from the UV analysis of sample oils in the commingled well was inserted into the standard plate and compared. The proportion of each single zone in the commingled producing well was identical with the proportion of the curve which is closest to the curve of sample oils formulated artificially. In the well QHD32-6-3 field, taking well A22 for example and using this method, the production contribution of a single zone was calculated. The result showed that the Nm4 zone is a major "contributor", the proportion of the Nm4 zone is 70%, and that of the Nm1 zone is 30%. The ultraviolet spectrum technique provided a new reservoir geochemical technique of monitoring production contribution, especially for biodegraded heavy oil, but it has some limitation, just depending on the GC fingerprint technique.     

Potential effect of sedimentary iron-phosphorus accumulation on frequent algal bloom in the Pearl River Estuary

Based on laboratory culture of harmful alga on iron and phosphorus uptake, and the study of accu-mulation of iron-phosphorus in cores and release of iron and phosphorus from surficial sediments collected in the Pearl River Estuary, the reasons of the high frequency of phytoplankton bloom therein are discussed. The results show that Fe starvation can make algal growth rate slow down and the peak of cell number decrease. Fe and P contents in algal cell bear a significant correlation and the molar ratio of P:Fe is ~356:1, suggesting that algal uptake of Fe and P is synergistic. Total Fe and total P in sediments are positively correlated and Fe-P is the main species of inorganic sedimentary P. Through continuous leaching with agitation, 34.26%―80.21% of exchangeable P and 4.04%―22.52% of ex-changeable Fe are released from surficial sediments, implying that the accumulation of Fe-P in sedi-ments is available for providing nutrients (P and essential Fe) for the demand of phytoplankton bloom. These factors might be responsible for a higher frequency of red tides than other marine regions.     

Impacts of recent El Niño Modoki on dry/wet conditions in the Pacific rim during boreal summer

Present work uses 1979–2005 monthly observational data to study the impacts of El Niño Modoki on dry/wet conditions in the Pacific rim during boreal summer. The El Niño Modoki phenomenon is characterized by the anomalously warm central equatorial Pacific flanked by anomalously cool regions in both west and east. Such zonal SST gradients result in anomalous two-cell Walker Circulation over the tropical Pacific, with a wet region in the central Pacific. There are two mid-tropospheric wave trains passing over the extratropical and subtropical North Pacific. They contain a positive phase of a Pacific-Japan pattern in the northwestern Pacific, and a positive phase of a summertime Pacific-North American pattern in the northeastern Pacific/North America region. The western North Pacific summer monsoon is enhanced, while the East Asian summer monsoon is weakened. In the South Pacific, there is a basin-wide low in the mid-latitude with enhanced Australian high and the eastern South Pacific subtropical high. Such an atmospheric circulation pattern favors a dry rim surrounding the wet central tropical Pacific. The El Niño Modoki and its climate impacts are very different from those of El Niño. Possible geographical regions for dry/wet conditions influenced by El Niño Modoki and El Niño are compared. The two phenomena also have very different temporal features. El Niño Modoki has a large decadal background while El Niño is predominated by interannual variability. Mixing-up the two different phenomena may increase the difficulty in understanding their mechanisms, climate impacts, and uncertainty in their predictions.     

Use of incremental analysis updates in 4D-Var data assimilation

The four-dimensional variational(4D-Var) data assimilation systems used in most operational and research centers use initial condition increments as control variables and adjust initial increments to find optimal analysis solutions. This approach may sometimes create discontinuities in analysis fields and produce undesirable spin ups and spin downs. This study explores using incremental analysis updates(IAU) in 4D-Var to reduce the analysis discontinuities. IAU-based 4D-Var has almost the same mathematical formula as conventional 4D-Var if the initial condition increments are replaced with time-integrated increments as control variables.The IAU technique was implemented in the NASA/GSFC 4D-Var prototype and compared against a control run without IAU. The results showed that the initial precipitation spikes were removed and that other discontinuities were also reduced,especially for the analysis of surface temperature.     

Trend Analysis of Hydro-Climatic Variables in Lake Baikal Basin

Water Resources - This study used the Innovative trend analysis method, Mann-Kendall, and Sen’s slope estimator test to investigate the mean annual precipitation, annual mean air temperature,...     

北京西山南部构造及新构造运动与区域岩溶地貌形成、演化

北京西山不仅以地质构造现象丰富、典型著称,而且发育了十分壮观的似峰丛岩溶地貌和石花洞等大型旅游洞穴。本文研究表明:地质构造和新构造运动是造成区域不同岩溶地貌单元差异的两个重要控制因素。地质构造控制了岩溶发育的宏观选择性作用;新构造运动特点决定了岩溶发育具阶段性和继承性,是该区一些特殊岩溶形态形成、发育的主要动因。      

北京西山地区岩溶地质旅游路线设置

北京西山地区岩溶形态类型典型,景观独特,发展岩溶地质旅游具有得天独厚的优势,根据其岩溶发育的特点和类型及地理位置、交通情况,可设置５条各具特色的岩溶地质旅游路线。      

天津蓟县中上元古界岩溶裂隙介质发育特征及其渗透性研究

本文以大量的裂隙测量、统计资料论述了裂隙几何参数(?)产状、隙宽和隙间距等在于同层位和区域上的变化规律。探讨了构造应力场、岩性、层厚诸因素的影响作用。并运用渗透张量理论对研究区岩溶裂隙的各向异性渗透性和非均质性逆行了研究,获得一些新认识,对查明岩溶水分布、运移规律有一定指导意久。      

桂林-阳朔一带峰林石山的形成类型及其岩性控制

<正> 匈牙利学者B.Bulla于1954年提出了关于岩石地貌学的概念,并对它作过如下描述:阐明岩石结构及其变化对地貌形态演化所产生的影响,这就是岩石地貌学的任务。不过B.Bulla及以后的许多作者都只提供一些主要类型岩石的地貌特征。我国曾昭璇教授早在五十年代就注意到这个问题,并于1960年发表了“岩石地形学”专著,对三大类岩石进行了地形描述。