151 resultados para Petroleum reserves


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The Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences has a long history in the R&D of catalysts and catalytic processes for petroleum and natural gas conversions in China. In this paper, results and features of some commercialized petrochemical catalysts and processes as well as newly developed processes for natural gas conversion in the pilot-plant stage are described. (C) 1999 Elsevier Science B.V. All rights reserved.

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Suction bucket foundations are widely used in the offshore platform for the exploitation of the offshore petroleum and natural gas resources. During winter seasons, ice sheets formed in Bohai Bay will impose strong impact and result in strong vibration on the platform. This paper describes a dynamic loading device developed on the geotechnical centrifuge and its application in modeling suction bucket foundation under the equivalent ice-induced vibration loadings. Some experimental results are presented. It is shown that when the loading amplitude is over a critical value, the sand at the upper part around the bucket softens or even liquefies. The excess pore pressure decreases from the upper part to the lower part of the sand foundation in vertical direction while decreases from near to far away from the bucket's side wall in the horizontal direction. Large settlements of the bucket and the sand around the bucket occur under the horizontal dynamic loading. The dynamic responses of the bucket with smaller size are heavier.

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同井是油气在建过程中的重要工程,一般分下套管和注水泥两个过程.本文结合作者近年来的研究,着重阐述了钻井液、前置液、水泥浆在环形空间中流动的流体力学问题,包括:高温高压下的水泥浆流变性、偏心环形空间中浆液的流动特性、钻井液-前置液和前置液-水泥浆界面的稳定性等,介绍了国内外学者对这些问题的研究进展,提出了今后应深入研究的问题.

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非牛顿流体;;本构方程;;流变测量;;流动稳定性;;收缩流动;;聚合物加工;;石油工业;;生物流体力学

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以发烟硫酸为磺化剂进行磺化反应,制备了石油磺酸盐.通过对原料性质、反应时间、反应温度对产品性能影响的考察,筛选出最佳的实验原料及制备的工艺条件.研究表明,磺化反应条件选取温度为40℃、反应时间为60min时,可以得到性能优良的石油磺酸盐产品.以海洋混合减一线油、辽河减四线油为原料制得的石油磺酸盐产品,提纯后具有较好的表面张力和界面性质.

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制作含水率与采出程度关系理论曲线常采用相渗曲线法和流管法两种方法.在采用相渗曲线法制作理论曲线时,采用统计回归分析相对渗透率与含水率的关系,导致在低含水饱和度时期含水率偏高,在高含水饱和度时期含水率偏低的问题,解决的方法是直接使用实验数据点计算.将体积波及系数取常数往往会得出"中低含水期开发效果较差,高含水期开发效果较好"的通用结论,解决的方法是分析体积波及系数与井网系统、流度比、渗透率变异系数的关系,建立统计关系式.

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Layered steam injection, widely used in Liaohe Oilfield at Present, is an effective recovery technique to heavy oil reserves. Which makes the steam front-peak push forward uniformly, the amount of steam injection be assigned rationally, and the effect of injection steam be obtained as expected. To maintain a fixed ratio of layered steam injection and solve the problem of nonadjustable hole diameter with the change of layer pressure in the existing injectors, a new method is proposed in this paper to design layered steam injectors based on the dynamic balance theory. According to gas-liquid two-phase flow theory and beat transfer theory, the energy equation and the heat conduction equation in boreholes are developed. By analyzing the energy equilibrium of water-steam passing through the injector hole, we find an expression to describe the relation between the cross-sectional area of injector hole and the layer pressure. With this expression, we provide a new set of calculation methods and write the corresponding computer program to design and calculate the main parameters of a steam injector. The actual measurement data show that the theoretically calculated results are accurate, the software runs reliably, and they provide the design of self-adjustable layered steam injectors with the theoretical foundation.

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Layered steam injection, widely used in Liaohe Oilfield at present, is an effective recovery technique to heavy oil reserves. Which makes the steam front-peak push forward uniformly, the amount of steam injection be assigned rationally, and the effect of injection steam be obtained as expected. To maintain a fixed ratio of layered steam injection and solve the problem of nonadjustable hole diameter with the change of layer pressure in the existing injectors, a new method is proposed in this paper to design layered steam injectors based on the dynamic balance theory According to gas-liquid two-phase flow theory and heat transfer theory, the energy equation and the heat conduction equation in boreholes are developed. By analyzing the energy equilibrium of water-steam passing through the injector hole, we find an expression to describe the relation between the cross-sectional area of injector hole and the layer pressure. With this expression, we provide a new set of calculation methods and write the corresponding computer program to design and calculate the main parameters of a steam injector. The actual measurement data show that the theoretically calculated results are accurate, the software runs reliably, and they provide the design of self-adjustable layered steam injectors with the theoretical foundation.

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对InnoSlab Laser用混合腔的输出光束质量问题从热透镜效应和腔镜的不对准两个方面的影响进行理论分析,并从远场光强分布、远场发散角、光腰半径、光束质量因子M2值和桶中功率曲线等几个角度进行了讨论,特别是离轴非稳腔方向上腔镜倾斜对光束质量的影响,利用M2值和PIB曲线两个参数共同评价非稳腔的光束质量,对目前并无统一标准的非稳腔光束质量评价问题提供了有意义的参考.

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草地在世界各种不同的气候带和土壤类型区均有分布,约占陆地面积的24%。尽管二十世纪中叶以来,人类通过各种措施,使氮素由大气圈进入生物圈的量已经翻了一翻,但是,草地生态系统由于没有得到足够的氮素补充,其生产力至少是季节性地受到氮素的制约。我国草原生态系统的退化与氮素匮乏已经引起了广泛重视。尽管一些研究者的工作已经涉及到氮素循环的一些方面,但是关于草原生态系统的氮素平衡过程的系统研究迄今尚未开展。地下器官中贮藏养分的积累是多年生牧草抵御不良环境条件的物质保障,碳水化合物是我国典型草原植物重要的贮藏营养物质。但是关于我国草原生态系统贮藏养分的研究还相当匮乏。值得一提的是,不合理的人类活动也加剧了草地生态系统氮素的损失,甚至对全球环境和人类健康产生了重要影响。为此,我们在中国科学院内蒙古草原生态系统定位研究站的羊草样地设计了氮素添加试验,采用15N稀释法对典型草原羊草群落的氮素吸收利用、氮素平衡进行了研究,并就氮素添加条件下,植物氮素利用与植物竞争的关系、氮素吸收分配与牧草生物产量与品质的关系进行了探讨。同时采用高效液相色谱对羊草群落植物贮藏碳水化合物的种类与含量进行了测定。 15N稀释法的试验结果表明:我国典型草原羊草群落吸收的氮素平均16.41%来源于肥料,83.59%来源于土壤。氮素添加不仅显著促进了羊草群落地上器官对肥料氮索和土壤氮素的吸收量,而且促进了地下器官对肥料氮素和土壤氮素的吸收量。生物量达到最大时,羊草群落吸收的氮素分配到地下器官中的比例平均为74.85%,分配到地上器官中的比例平均为25.15%。植物吸收的肥料氮素在地上和地下器官之间的分配比例约各占50%。 在我国典型草原羊草群落,植物对肥料氮素的回收率仅为31.61%,氮素添加显著影响羊草群落植物对肥料氮素的回收,随着氮素添加量的提高,地上和地下植物器官对肥料氮素的回收量均显著提高。凋落物的肥料氮素回收率为2.92%,地下凋落物的回收率显著高于地上凋落物。肥料氮素的土壤存留率为36.16%,主要分布在地表至40cm的土层范围内(>95%)。各土层存留的标记肥料氮素量均随着氮素添加量的增加而显著提高。肥料氮素的当季损失率为21.77%-43.38%。风险:收益分析表明,在本试验条件下,添加5.25gN/m2与28gN/m2的处理风险大于收益,添加17.5g/m2的处理风险最低,收益最高,在草原生态系统的管理中可以参考。 为了了解羊草群落植物的竞争能力是否对羊草群落植物的相对多度有影响,我们对不同盖度的10个物种的15N吸收速率、15N分配、植物组织氮素含量、单株生物量、根/冠比、氮素生产力等反映植物竞争能力的指标进行了测定和分析。发现向根系的氮素分配比例、根/冠比、和氮素生产力与植物的相对盖度显著正相关,向地上器官的氮素分配比例、氮素吸收速率与相对盖度呈显著负相关,而植物组织氮素含量、和单株生物量与植物相对盖度无关。 试验前,我们认为氮素吸收速率应该与植物的相对多度显著正相关,但是本试验发现却是显著负相关。这一结果说明,高的氮素吸收速率并不能代表较高的竞争能力,而是稀少植物能够与优势植物共存的一种生理机制。 氮素的吸收与分配显著地影响牧草的生物产量和品质。氮素添加提高了羊草生物量,促进了生物量向地上器官的分配比例,降低了向根系的分配比例,使根/冠比显著降低。氮素添加促进了羊草对氮素的吸收以及向茎叶中的分配比例,降低了向根系的分配比例,提高了羊草各器官的氮素含量和地上器官的蛋白质含量,对根系的蛋白质含量无显著影响。本试验条件下,氮素添加水平为17.5gN/m2时,羊草根、茎、叶生物产量均最高。与17.5gN/m2的处理相比较,添加28gN/m2的处理,羊草的生物产量以及牧草蛋白质含量均无显著差异。初步认为,本实验条件下,17. 5gN/m2是较为适宜的氮素添加量。 地下器官中贮藏养分的积累是多年生牧草抵御不良环境条件的物质保障,碳水化合物是我国典型草原植物重要的贮藏营养。采用高效液相色谱(HPLC)对羊草群落地下器官的贮藏性碳水化合物进行了分析。结果表明,羊草群落地下贮藏碳水化合物种类主要包括甘露糖醇、果聚糖、蔗糖、葡萄糖和果糖。其中甘露糖醇是最主要贮藏碳水化合物,约占60%;其次是果聚糖,约占30%。氮素添加量对羊草群落地下贮藏碳水化合物有显著影响。在0~50 g NH4N03. m-2.yr-1范围内,随着氮素添加量的增加,总糖、果聚糖、甘露糖醇的含量均逐渐升高。氮素添加时期对羊草群落地下贮藏碳水化合物含量亦有显著影响。7月初(雨季)添加氮素比4月份(牧草开始返青)更有利于牧草地下贮藏碳水化合物的积累。 对羊草根茎中的贮藏性碳水化合物的测定结果表明,羊草根茎中的贮藏碳水化合物组分主要包括果聚糖、甘露糖醇、蔗糖、葡萄糖和果糖。其中果聚糖是最主要贮藏碳水化合物,约占60%:其次是甘露糖醇,约占20%。氮素添加量对羊草根茎中的贮藏碳水化合物有显著影响。在0~17.5 g N/m2范围内,随着氮素添加量的增加,总糖、果聚糖、甘露糖醇的含量均逐渐升高。氮素添加时期对羊草根茎中的贮藏碳水化合物的含量亦有显著影响。在7月初添加氮素比4月份添加氮素更有利于贮藏碳水化合物的积累。

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The Hainan gibbon (Nomascus hainanus) is one of the most endangered primates in the world, confined to mature natural forest in Hainan Island, China. We assessed changes in habitat condition on the island between 1991 and 2008, using vegetation maps generated by remote-sensing images. We defined forest suitable for gibbons based on composition, tree size and canopy cover. During the 17-year period, the area of suitable gibbon forest decreased by 540 km(2) (35%) across the whole island, and by 6.3 km(2) (7%) in the locality of the sole remaining gibbon population at Bawangling National Nature Reserve. The forest patches large enough (>1 km(2)) to support a gibbon group decreased from 754 km(2) to 316 km(2) in total area, and from 92 to 64 in number. Suitable natural forest was mainly replaced by plantations below 760 m, or degraded by logging, grazing and planting of pines above 760 m. Meanwhile, forests in former confirmed gibbon areas became more fragmented: mean area of patches decreased by 53%. We mapped the patches of natural forest in good condition which could potentially support gibbons. We recommend a freeze on further expansion of plantations between core patches at Bawangling, Jiaxi-Houmiling and Yinggeling Nature Reserves in accordance with forest protection regulations; establishment of nature reserves in currently unprotected natural forest patches elsewhere in line with the local government's nature reserve expansion policy; and active natural-forest restoration between remaining fragments at Bawangling. (C) 2010 Elsevier Ltd. All rights reserved.

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Rhus chinensis, a species used in folk medicine by Chinese native people, the anti-HIV-1 activities of the petroleum ether, ethyl acetate, butanol and aqueous extract of Rhus chinensis, named as RC-1, RC-2, RC-3 and RC-4, respectively, was evaluated. The

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Four new compounds, including three secolignans (1-3) and one tetrahydrofuran lignan (4), were isolated from the petroleum ether and EtOAc fractions of Peperomia heyneana. These compounds were accompanied by eight known secolignans, one known tetrahydrofu

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Aim of the study: Previously, we reported that the petroleum ether fraction, RC-1, and EtOAc fraction, RC-2, of the medicinal plant Rhus chinensis showed potent anti-HIV-1 activities. To address anti-HIV-1 constituents of RC-1 and RC-2, 17 compounds were