Green hydropower: a new assessment procedure for river management

Hydropower is the most important renewable electricity source worldwide. It shows clear advantages for the global CO₂ balance but creates serious ecological impacts on a local scale. As a consequence, concern for the conservation of natural river ecosystems is growing within society and more people are willing to pay extra for so‐called ‘green electricity’. The definition of ‘green’, however, is not straightforward and customers cannot directly examine the quality of electricity products. Therefore, credible certification of high ecological standards is essential for successful green electricity marketing. In this paper we introduce a new assessment procedure for evaluating environmentally compatible hydropower production. This so‐called ‘Green Hydro’ concept was developed in the context of a multidisciplinary case study on a 400 MW hydropower scheme in the Southern Alps of Switzerland. The concept guarantees both general standards for different schemes operating in different types of watersheds and flexibility for local particularities. We developed an environmental management matrix that considers basic criteria and eco‐investments and covers five environmental areas of concern (i.e. hydrological character, connectivity, morphology, landscape, and biological communities). The ecological perspective is complemented by five management domains (i.e. instream flow regimes, hydropeaking, reservoir and bedload management, and power plant structures). Applying assessment and modelling tools for the Green Hydro procedure showed that dynamic habitat models allowed quantification of the effects of different instream flow regulations at morphologically distinct sites. In this case, morphological restoration could be more beneficial than increasing the minimum flow. The first experience with the Green Hydro certification is encouraging. So far, 13 facilities have successfully passed the certification procedure. They produce a total of 186 GWh green electricity per year, which is sufficient for the supply of almost 40 000 households in Switzerland. Copyright © 2004 John Wiley & Sons, Ltd.     

安塞油田补偿成藏现象探讨

安塞油田三叠系延长组长6油层发育的区域，很少有长2、长3油层组叠加发育，而长6油层发育较差的区域，似乎是为了补偿而广泛发育诸如长2、长3乃至侏罗系油层。通过对安塞油田中生界三叠系延长组沉积特征、烃原岩发育及分布、油气运移、圈闭条件及类型进行综合研究，认为补偿成藏现象与鄂尔多斯盆地安塞油田油气运移规律和长4＋5盖层发育状况有重要关系，而长4＋5盖层发育程度是补偿成藏现象发生关键因素。补偿成藏现象对安袈油田油气勘探与开发具有重要的指导意义。     

Ability of organic and inorganic bedding materials to promote growth of environmental bacteria

The major objective of this study was to contrast the ability of 4 commonly utilized bedding materials to promote growth of environmental bacteria under controlled conditions. A second objective was to describe the relationship between bacterial growth and specific biochemical or nutritional properties of these bedding materials. Unused samples of clean sand (CS; n = 20), recycled sand (RS; n = 21), digested manure solids (DS; n = 15), and shavings (SH; n = 15) were collected from bedding storage areas on 49 commercial Minnesota and Wisconsin dairy farms. Sterilized bedding samples were inoculated with Klebsiella pneumoniae and Enterococcus faecium then incubated, in triplicate, for 72 h at 37°C. Subsamples were collected after 0, 24, 48, and 72 h of incubation for culture and enumeration of bacteria. Subsamples of bedding were also tested for pH, total C content (%), and total N content (%). If bacterial growth occurred, peak levels were typically achieved within 24 h. Digested manure solids promoted the greatest amounts of growth of K. pneumoniae, followed by RS and then SH, whereas CS promoted the least. There would seem to be a tradeoff in selecting SH as a bedding material, because it supported moderate growth of K. pneumoniae but caused a rapid decline in the numbers of E. faecium. However, RS, CS, and DS each only supported relatively small amounts of growth of E. faecium, so the benefit of SH relative to other bedding materials is limited. High bedding pH may partially explain why some bedding materials supported growth of E. faecium (e.g., DS and RS). Both high bedding pH (e.g., as for DS or RS) and high total C (%) content (e.g., as for DS and SH) may partially explain why some bedding materials supported growth of K. pneumoniae.     

冲砂泡沫流体室内携砂规律研究

为了解冲砂泡沫流体的携砂规律,在自制的试验装置上研究了冲砂时间与砂面高度的关系以及井筒倾角和砂粒直径对携砂率和停留时间的影响。试验结果表明,砂面高度首先快速下降,然后缓慢下降直至趋于平缓;直径小于0.5 mm的砂粒在泡沫中携砂率大于90%,此时井筒倾角对携砂率和停留时间基本没有影响;直径1.0～1.5 mm的砂粒,携砂率随倾角的增大先减小后增大,停留时间随倾角的增大而缩短,倾角在45°～60°时携砂率最小。对于相同的倾角,砂粒直径越大,携砂率越低且停留时间越长。垂直井筒中砂粒以均匀悬浮方式随泡沫流体一起运移;倾斜井筒中砂粒以跳跃方式运移,且明显滑向较低一侧。     

环保型堵水凝胶的实验研究

针对中温油藏,在模拟油藏温度75℃,以相对分子质量400万、800万、1200万、浓度为0.5%～2%自制阴离子型低水解度(<5%)聚丙烯酰胺(PHPAM)配与0.2%～0.8%环保交联剂聚乙烯亚胺(PEI)交联形成环保堵水凝胶。通过对聚合物浓度,交联剂浓度等影响因素的研究,得出聚合物和交联剂加量不宜过多,否则会出现自聚和过度交联的现象。通过对配制水矿化度的影响研究,发现矿化度变大,堵剂成胶时间延长,成胶时间可控。热稳定性实验结果表明,该堵剂具有良好的稳定性,能稳定4个月以上,是一种性能良好的长期堵水剂。     

幂律流体中岩屑颗粒沉降速度实验

钻井过程中,任何井型都需要钻井液有效携带岩屑上返,以保持井眼清洁;但由于岩屑颗粒与钻井液存在密度差,遇到接单根、停钻等工况,岩屑颗粒就会在钻井液中沉降。对于大斜度井和水平井,岩屑沉降后会堆积在造斜和水平井段,形成岩屑床,造成恶性井下安全事故,因此,深入研究岩屑颗粒在钻井液中的沉降规律十分重要。文中首先综述了不同形状、不同粒径的固体颗粒在牛顿流体中的阻力系数和沉降速度计算模型,分析了牛顿流体中固体颗粒雷诺数和阻力系数之间的关系;应用与研究固体颗粒在牛顿流体中沉降的相同方法,并通过室内实验,得到了不同粒径岩屑颗粒在幂律流体中的沉降速度模型、颗粒雷诺数与阻力系数之间的关系模型。     

水驱油田理论含水上升率预测新方法及其应用

含水上升率是水驱油田开发效果评价和指标预侧的关键参数。文中基于甲、乙、丙、丁4种水驱特征曲线,推导出了含水上升率与含水率的理论关系式,并结合相渗曲线关系式,确定了含水上升率表达式的系数。在渤海C日油田的实际应用结果表明：基于甲型水驱特征曲线的理论含水上升率在含水率为50%处达到最大值,特征曲线关于该点对称;基于乙、丙型水驱特征曲线的理论含水上升率曲线,随含水率升高始终呈下降态势;基于丁型水驱特征曲线的理论含水上升率曲线,以中高含水期为转折点,呈先升后降的变化态势。通过将理论曲线与C日油田实际数据进行对比,得出油田适用的水驱特征曲线为丙型水驱特征曲线。由此可见,可以利用含水上升规律进行水驱特征曲线的判别选取。     

LNG接收站在海水低温条件下的ORV节能运行技术

为了保证海水温度不影响LNG接收站开架式气化器(ORV)气化的LNG额定流量,ORV设计文件要求当海水温度低于5.5℃时,不得运行ORV,需改用浸没燃烧式气化器(SCV);但由于SCV运行成本远远高于ORV,因此,如何在海水温度低于5.5℃时仍然能运行ORV便成了研究的重点。在海水低温条件下运行ORV的关键是确定ORV最小海水流量和最大LNG流量。因此,首先以ORV性能曲线为基础,确定其机械限定LNG流量和特定条件下ORV入口海水温度在2.5~5.5℃范围内的固有性能曲线,然后通过实验获得特定条件下入口海水温度在1.0~2.5℃范围内的试验性能曲线,进而分段建立特定条件下入口海水温度、LNG入口压力、最大LNG流量与最小海水流量间的计算模型,并由1st Opt软件采用多元非线性拟合确定模型系数,最后由能量守恒定律求解实际运行中的ORV最小海水流量和最大LNG流量,同时设计出了计算软件。实际运行结果表明该软件计算的最大相对误差仅为0.94%。在中国石油大连液化天然气有限公司LNG接收站的实际应用效果表明:在2012—2013年间,海水低温下ORV节能运行技术为该LNG接收站节约气化成本5 982万元。     

Warm asphalt mixtures produced with addition of CCBit

There is a growing concern with the environmental damage caused by the various types of industrial activities. Because of that, research in paving has sought alternatives to reduce fuel consumption and emissions of greenhouse gases generated by those. The warm mixtures have received increasing attention because they are capable of decreasing the mixture and compaction temperatures of asphalt mixtures. The objective of this study was to evaluate the effect of the incorporation of CCBit from the mechanical characterization of asphalt mixtures. From the results, it was found that the incorporation of CCBit has the advantage of reducing mixing and compaction temperatures without harming their mechanical behavior.     

催化加氢-溶剂抽提联合工艺制备高CA值环保型橡胶填充油

以绥中36—1环烷基原油减二线馏分油为原料,采用催化加氢-溶剂抽提联合工艺制备环保型橡胶填充油。通过催化加氢工艺饱和大部分的多环芳烃,加氢油经一次糠醛抽提除去饱和的链烷烃和环烷烃后再经二次糠醛抽提除去多环芳烃,制备出CA值为18．59％的高芳碳环保型橡胶填充油。结果表明,该联合工艺制备的橡胶填充油与单纯溶剂抽提丁艺所得产品相比具有芳碳含量高、闪点高等优点。将该方法制备的环保型橡胶填充油与国内外典型环保型橡胶填充油对比发现,该产品有良好的应用性能。