底水油层水平井产液剖面均衡性评价

胜利油田开采底水特征高含水油层的水平井数量多,其中油层向水平井非均衡供液现象普遍。为评价此类水平井产液剖面均衡性,量化其生产动态改善潜力,定义了产液剖面基尼系数GN,并结合现场案例介绍其计算方法,随后统计胜利油田60口样本井,分析GN对见水时间tRL和底水突破前累积产油量QRL的影响,最后据此对GN分级。计算和分析结果表明:GN可以整体表征实际非均衡产液剖面偏离理想均衡产液剖面的程度,通常取值0~1之间,数值越大,均衡性越差;划分GN0.1为产液剖面不均衡,其样本井数54口,占比90%,以理想均衡产液状态为基准,tRL和QRL分别至少有100%和69.5%的提升潜力。     

Surflan and oryzalin impair reproduction in the teleost medaka (Oryzias latipes)

We conducted studies to determine if the xenoestrogens Surflan and its active ingredient oryzalin, affect indices of reproductive fitness in medaka (Oryzias latipes). Oryzalin (0.5, 0.25mg/l) or Surflan (2.0 microl/l) and oryzalin (0.5mg/l) significantly increased the mean number of non-fertilized eggs produced by treated females paired with untreated males, or by untreated females paired with treated males. Oryzalin (1.0, 0.5, 0.25mg/l) and Surflan (3.8, 2.0, 1.0 microl/l) significantly affected the time to hatch of eggs from treated females paired with untreated males, and from untreated females paired with treated males. Surflan (3.8, 2.0, 1.0 microl/l) induced intersex lesions in 80-100% of males. Oryzalin-exposed males exhibited a significant increase in the incidence of necrotic spermatids and necrotic spermatogonia, while oryzalin-exposed females had significantly fewer immature oocytes and an increase in the occurrence of hyperplastic ovaries. Our results indicate that Surflan and oryzalin affect both reproduction and gonadal histology in male and female medaka.     

The use of the marine biotic index AMBI in the assessment of the ecological status of the Obidos lagoon (Portugal)

This study reports the longitudinal distribution of sediment properties, including inorganic and organic contaminants, and the structure of the benthic community in Obidos lagoon, a coastal system permanently connected to the sea and with negligible freshwater sources. Sediments from the upper to central lagoon consist of fine particles (91%) and from the lower lagoon of sands (94%). Chemical composition is strongly correlated to the percentage of fine particles. Contamination is relatively low in those sediments suggesting the effect of diffuse sources. The increase in organic matter content from down- to upstream areas was associated with the dominance of opportunistic species, while sensitive and indifferent species to organic enrichment were mainly associated to the clean sandy downstream area. The marine biotic index (AMBI) was suitable for the discrimination of the biological and environmental gradients in the Obidos lagoon and was highly related with the gradient of organic matter content in this system.     

Ecological quality assessment of small estuaries from the Portuguese coast based on fish assemblages indices

The importance of establishing the ecological quality of estuarine systems has been widely acknowledged and led to the development of several fish community-based multimetric indices. Nevertheless, a question rose about the accuracy of these tools when natural disturbance is acting upon the organization of the systems’ communities. Four multimetric indices were used to examine their ability to differentiate the ecological status of five small estuarine systems (southern Portugal), and also to test if they reflected the level of anthropogenic pressures. Fish assemblages from Mira, Odeceixe and Aljezur (in the Southwest coast), Gilão and Bensafrim (in the South coast) estuaries were sampled seasonally for one year, and anthropogenic sources of pressure were identified and quantified. We found that although the applied indices provided information on ecological condition differentiation among systems, they are unable to explain different classes of ecological status in systems with equivalent pressure levels.     

Introduction to hydromechanical well tests in fractured rock aquifers

This article introduces hydromechanical well tests as a viable field method for characterizing fractured rock aquifers. These tests involve measuring and analyzing small displacements along with pressure transients. Recent developments in equipment and analyses have simplified hydromechanical well tests, and this article describes initial field results and interpretations during slug and constant-rate pumping tests conducted at a site underlain by fractured biotite gneiss in South Carolina. The field data are characterized by displacements of 0.3 μm to more than 10 μm during head changes up to 10 m. Displacements are a hysteretic function of hydraulic head in the wellbore, with displacements late in a well test always exceeding those at similar wellbore pressures early in the test. Displacement measurements show that hydraulic aperture changes during well tests, and both scaling analyses and field data suggest that T changed by a few percent per meter of drawdown during slug and pumping tests at our field site. Preliminary analyses suggest that displacement data can be used to improve estimates of storativity and to reduce nonuniqueness during hydraulic well tests involving single wells.     

基于地基GNSS观测数据的贵州高原地区水汽层析精度分析

利用精密单点定位(PPP)技术处理贵州地基GNSS观测数据,获得高精度天顶对流层延迟(ZTD),进而开展水汽反演获得大气可降水量(PWV)产品。基于斜路径可降水量(SWV),使用自适应联合代数重构算法进行三维水汽层析,空间分辨率优于30 km×30 km,时间分辨率为5 min。以无线电探空数据为参考评估ZTD和PWV精度,其RMS分别为3.55 mm和1.03 mm。以ERA5再分析资料为参考评估三维层析精度,无暴雨发生时,三维层析相对误差不超过10%,偏差最大值为1.03 g/m³。以无线电探空数据为参考评估三维层析精度,层析结果与无线电探空数据的相关系数在0.97以上,具有较好的一致性。贵阳站和威宁站的平均RMS分别优于0.5 g/m³和1.2 g/m³。