Effects of high pressure argon treatments on the quality of fresh-cut apples at cold storage

High pressure (HP) argon (Ar) processing that makes argon and water molecules form clathrate hydrates to restrict intracellular water activity and enzymatic reactions. This can be used in the preservation of fruits and vegetables. Effects of HP (150 MPa) Ar treatments on preserving fresh-cut apples were investigated at 4 °C for two weeks. Respiration rate and ethylene production of fresh-cut apples treated by the HP (150 MPa) Ar for 10 min were lower apparently in comparison with those untreated and treated by flushing with Ar and the HP air for 10 min. The HP Ar treatment delayed browning and microbial growth of fresh-cut apples at cold storage, because the populations of both mesophiles and psychrotrophs did not exceed 6.0 log cfu/g, and those for molds and yeasts were less than 3.0 log cfu/g after two weeks storage. HP Ar treatment did not affect the content of titrated acidity and soluble solids, and significantly reduced the total phenolics decrease in fresh-cut apples (p < 0.05). Dipping into chemical solution, such as 0.5% ascorbic acid (AA), 0.5% citric acid (CA) and 0.5% calcium chloride (CC) for 5 min could reduce the changes in the color and firmness of apple wedges during HP operation, and the combined HP Ar with dipping treatment remained good sensory attributes of fresh-cut apples for 12 days at 4 °C. These results indicated the HP Ar treatment could be an effective method for improving the quality of fresh-cut apples at cold storage conditions.     

APJL-3低度交联体系的研究与应用

AP型疏水缔合聚合物与普通部分水解聚两烯酰胺比较，具有更好的增粘和抗温抗盐能力。应用AP型聚合物研制的APJL-3低度交联体系比HPAM交联体系抗温、抗盐和抗剪切性能明显增强，驱油效率提高，现场试验也获得了理想的增油效果，显示了良好的应用前景。介绍了APJL-3低度交联体系配方的优选，评价了体系的抗温、抗盐和抗剪切性能，并在室内模拟了调驱效果。     

高压往复泵性能计算机测试系统的开发与应用

介绍了一种高压往复泵性能计算机测试系统,并对系统的硬件组成为设计选择依据以及软件的设计思想、工作流程、主要功能和使用情况作了详细介绍。     

Characterization of Gas Hydrates by Modulated Differential Scanning Calorimetry

Abstract

Modulated Differential Scanning Calorimetry (MDSC) has been applied to the study of methane, ethane, and propane hydrates at different hydrate and ice concentrations. The reversing thermodynamical component of the MDSC curves, makes it possible to characterize such hydrates.

Methane and ethane hydrates show the melting-decomposition peak at a temperatures higher than the ice contained in the sample, while propane hydrate melts and decomposes at a lower temperature than the ice present in the sample. The hydrate peaks tend to disappear if the hydrate is stored at atmospheric pressure. Guest size and cavity occupation fix the heat of dissociation and stability of the hydrates, as confirmed by parallel tests on tetrahydrofurane hydrates.     

置换减压法开发天然气水合物工艺及数值模拟

天然气水合物是能源领域尚未开发的领域之一,有巨大的潜力来满足未来的能源需求,降压、热刺激、碳交换和抑制剂注入是其生产过程中涉及的四种开采方法。文章提出了采用双水平井降压 ＋二氧化碳置换法开采天然气水合物,应用油藏模拟器 ＣＭＧ对矿藏条件下水合物进行数值模拟分析,模拟了多组分、多相流体和热流在地下的流动和传输,以及甲烷饱和度和温度分布,估算了水合物解离产气量和出砂量。模拟结果表明,随着开采的进行,甲烷饱和度降低,顶部的水合物优先开始分解,二氧化碳置换区域地层温度提高 ２～５℃,温度升高促进甲烷持续解离,形成了一个连续交换和生产的循环过程;同时随着甲烷产量的增加,生产井出砂量也随之增加。采用双水平井开采技术,扩大了水合物储层的波及面积,有效增加了产气量,达到商业开采价值规模。研究结果为科学评价天然气水合物开采技术的可行性、经济性提供了理论依据。     

季铵盐型阳离子沥青乳化剂的合成及影响因素研究

采用某酚、环氧氯丙烷、三乙胺同时加料的方法合成了季铵盐型阳离子沥青乳化剂，对合成的轧化剂轧化沥青的性能进行了测试。重点研究了溶剂、反应温度、反应时间对该合成反应的影响，并确定了最佳反应条件为甲醇和水的混合溶剂为较适宜的溶剂；最佳的反应温度为70C；反应时间4h为宜。     

季铵盐型阳离子沥青乳化剂的合成及临界胶束浓度测定

采用某酚、环氧氟丙烷、三乙胺同时加料的方法合成了季铵盐型阳离子沥青乳化剂，并对合成产物的紫外光谱、临界胶束浓度及合成乳化剂乳化沥青性能进行了测试。重点介绍了季铵盐型阳离子沥青乳化剂紫外光谱和临界胶束浓度的测定。     

沙漠公路固化材料的研究与应用

本文介绍新型NS系列固化材料的特性及其在塔里木沙漠石油公路筑路工程中的应用。经现场筑路证明，以水淬矿渣与多种添加剂为主要成分的NS固化材料能就地固结沙漠沙，使铺筑后的道路具有较小的干燥收缩、温度收缩和较好的抗冻融耐久性，可采用集中搅拌法或路拌法施工。     

DSC技术在天然气水合物研究中的应用

介绍了DSC技术的基本原理,在天然气水合物热力学研究、动力学研究、水合物抑制剂评价中的应用。DSC技术作为一种热分析方法,它具有试样微量化、不用溶剂、适用范围广、快速简便等优点,为探索天然气水合物的特性提供了又一种有效的技术手段。     

碱渣土工程性能的试验研究

天津经济技术开发区和保税区的发展，需要对大量的低洼地进行回填，为了利用天津碱厂排出的大量工业废料取代价格较高的普通回填用土，自1992年以来对碱渣的性质做了大量研究工作，相继提出以不同材料，按不同配比拌和碱渣形成碱渣土进行低洼地填垫的方案，并对其物理力学指标通过室内和现场试验进行了检测，结果表明碱渣土可以用于低洼地的回填。     

TC6—ZY单液法复合堵水剂的研制及应用

讨论了影响ＴＣ６－ＺＹ单液法复合堵水剂性能的配方因素，对堵剂的性能进行了综合评价，介绍了选井原则，堵剂配方和施工工艺。室内试验和现场应用表明：该堵剂具有可泵性好、固化时间可调、强度高、有效期长、封堵率高，易解堵等优点，主要用于近井地带的非选择性封堵。     

地层测试中不同探针污染驱替效率研究

钻井过程中钻井液和固体碎屑混合而成的泥浆滤液渗透进入地层,对原始地层液体造成了不可避免的污染。取样探针的形状和布局对于在短时间内获取低污染样品有着十分重要的影响。采用合理简化,针对污染侵入和取样2个阶段建立了相关联的一系列模型,对不同类型探针和不同地层条件下的抽取过程用ECLIPSE软件进行数值模拟。通过对各个实例模拟结果的分析比较,为探针的设计和选择提供了依据。采用扩大探针口尺寸、在垂直方向上拉长探针、增加同一组件上的探针口数量和同一地层测试器(MDT)上携带更多探针组件的方式都增加了探针口面积,从而缩短达标作业时间。对于竖向与水平向渗透率比较小的地层环境,在探针口面积相同的情况下,竖直方向尺度较小的探针能更有效率地获得达标样品。     

聚合物驱厚油层分部位测试技术探讨

在三次采油注聚合物试验中，掌握厚油层注聚合物开采动态，获取厚油层各部位压力，含水及产液量变化数据，对分析厚油层注聚合物开采效果至关重要，本分析了厚油层分部测试采用预吊式和环深测试两种方法。为搞好聚合物驱油评价提供了依据。     

Dissociation Rate of THF-methane Hydrates

Abstract

A number of papers and research projects suggest that stranded natural gas can be transported in a solid hydrate state at higher temperatures or lower pressures compared to conventional transportation systems (LNG and CNG). The self-preservation effect of methane hydrate can probably be improved by the use of a third component besides CH₄ and water. Tetrahydrofuran (THF) is a promoter that greatly reduces the required formation pressures. In the present work the influence of THF on the decomposition kinetics of mixed THF-CH₄ hydrates was studied to evaluate the THF stabilization effect. The experimental work, carried out with the help of a reaction calorimeter, has revealed that the dissociation rate of mixed THF hydrates is lower (on average by one order of magnitude) than that of simple methane hydrates. Mixed hydrates can also be stored for short periods at temperatures over 0°C. However, the best preservation conditions (among the experimented ones) are realized at ?1°C and 3 MPa. (about 66 days required for complete dissociation).     

油气成藏动力学研究系统概要(上)

广义的油气成藏动力学研究 ,泛指一切有关油气生、排、运、聚的机理性研究。文中所说的油气成藏动力学研究系统 ,是指在某一特定的地质单元内 ,在相应的烃源体和流体输导体系发育的格架下 ,通过对温度、压力 (势 )、应力、含烃流体等各种物理、化学场的综合定量研究 ,在古构造发育的背景上历史再现油气生、排、运、聚乃至成藏全过程的多学科综合研究体系 ,这实际上是含油气系统意义上的一种定量动力学研究体系。油气成藏动力学研究系统由模型研究与模拟研究两部分组成 ,在理论上集成了石油地质学的动力学研究成果 ,整个研究过程是在烃源体和流体输导体系的三维格架上进行的。这个研究系统有强大的计算机工作平台支持 ,模型研究与模拟研究结果的迭代反馈降低了地质解释中的多解性 ,是新一代的石油地质勘探研究工作系统。该系统在珠江口盆地的实际应用 ,表明了这一研究系统的具体应用效果     

乙酸对长石砂岩溶蚀作用的实验模拟

本文描述动态条件下开放体系中的长石砂岩溶蚀模拟实验。实验样品为陕甘宁盆地下石盒子组绿灰色中粒蚀变凝灰质长石砂岩岩心，采用地层水中普遍存在的乙酸配制成反应介质，动态溶蚀实验时间为８１３ｈ。溶蚀后岩样的次生孔隙显著增加，物性明显改善，检测到长石蚀变形成的高岭石和微晶石英。本文探讨了实验样品中矿折溶蚀序列，以及长石矿物溶蚀、次生孔隙、新生矿物的形成机理。     

The Equilibrium Data and Thermodynamic Modeling of Hydrate Formation for CO2 and Mixtures of CO2 and CH4 in the Presence of Methanol

Equilibrium data for the novel formation of hydrates of carbon dioxide and mixtures of carbon dioxide and methane in 20 wt% aqueous methanol solution were measured by the constant-volume method. For CO₂, these data were taken at the temperature and pressure ranges of 264.7–270.7 K and 1,470–3,160 kPa, respectively. For mixtures of carbon dioxide and methane, these data were taken at the temperature and pressure ranges of 262.9–273.7 K and 1,370–5,100 kPa, respectively. The data obtained for CO₂ in 20 wt% aqueous methanol solution were in disagreement with previously published data, but there was good agreement between our data and the predictions of thermodynamic models. The Peng-Robinson equation of state (PR EOS) coupled with the Wong-Sandler (WS) mixing rule was used to obtain the fugacities of the components in the gas and aqueous liquid phases. The PR EOS was then coupled with van der Waals-Platteeuw (vdW-P) hydrate model and applied to predict hydrate-formation conditions in the system containing methanol. The model predictions demonstrated good agreement with the experimental data.     

海洋水合物地层钻井用聚合醇钻井液研究

针对海底天然气水合物地层的独特特性,在充分考虑现有的常用聚合醇钻井液体系的基础上,论述了适合海底天然气水合物地层钻井用含动力学抑制剂的聚合醇钻井液的室内研究情况。结果表明,该体系具有优良的页岩抑制性和水合物抑制性、良好的低温流变性、稳定性和润滑性等特点,能够有效保持井壁稳定,是一种非常适合海底天然气水合物地层钻探的钻井液体系。