影响加氢柴油介电精制效率的因素

根据介电力学原理,在自行设计的介电动力学精制工艺实验台架装置中,研究了影响加氢柴油中的超细固体微粒去除效率的因素。运用油液中固体颗粒物的显微镜计数法,测定了不同条件下加氢柴油中的固体微粒,比对ISO液压传动油液中固体颗粒污染等级代号,确定了精制后加氢柴油的固体微粒等级。研究结果发现,在介电陶瓷的介电常数ε＜12 000的范围内,介电精制效率随介电常数的升高而升高,但当ε＞12 000后精制效率降低;加氢柴油中颗粒物的去除率随分离电压的增大呈先增加后降低的变化趋势,在分离电压为4 000V时介电精制效果最好;在 ε=12000、分离电压为4 000V、流量为36.4mL/min时,加氢柴油中颗粒物的去除率最大,为99.33%,精制后加氢柴油的固体微粒等级达到2级。     

石化企业低压变频器电压暂降耐受能力分析与测试

变频器是电力电子设备,抵御电压暂降能力弱,多次因“晃电”影响装置运行。研究了变频器能量平衡关系,推导了在三相短路下,变频器暂降持续时间。利用持续时间方程,分析影响变频器免疫的关键因素。搭建变频器实验平台,实测不同暂降深度、不同负荷率下,变频器暂降免疫能力。变频器暂降拐点与负载率相关,负载越重耐受暂降时间越短。变频器暂降深度与频率相关,频率越低耐受电压暂降能力越强。依据测试结论,分析不同暂降免疫手段的适用范围。外加电源适合关键工艺,改变控制策略适合非核心工艺。分析得到的结论可为石化变频器暂降治理提供参考。     

电泳法清除钻屑微粒的初步研究

鉴于目前尚无清除泥浆中3μm以下钻屑微粒的方法,根据泥浆中泥页岩微粒带负电的特征,研究了清除钻屑微粒的新方法——电泳法。研究结果表明,电泳法可以清除花浆中40μm以下的岩屑颗粒,对于3μm以下的微粒具有独特的清除效果;影响电泳法清除岩屑微粒的主要因素是电压、极距和时间,控制这些因素,能有效地稳定和改善泥浆的流变性能。此外,电泳法还可清除部分非带电固体微粒。因此,用电泳法可消除泥浆增粘的内在因素,减少降粘剂和用水量,不污染环境,提高钻井速度,具有广阔的应用前景。     

介电实验测量与饱和度模型建立及应用

低孔隙度低渗透率储层的孔隙结构比较复杂,当地层水矿化度未知时,难以利用电阻率区分流体性质。介电测井仪器可以测量地层的介电常数,利用含不同流体的地层介电常数之间的差异可以较好地区分地层的含流体性质。基于介电实验以及介电频散分析,建立与ADT阵列介电测井仪器测量频率匹配的2种饱和度解释模型——仿Archie公式和体积模型,应用于近平衡钻井的A井ADT测井资料处理,通过与岩心实验测量及核磁共振束缚水饱和度对等处理结果的对比分析,证实了所建立饱和度模型及实验参数的可靠性。     

根据多频介电测量获得地层特征参数

为了区别淡水和石油，上世纪70年代研究成功介电测井，单独使用各种电阻率测井来区别淡水和石油是困难的。在环境条件下，水的介电常数至少比石油或岩石基质介电常数高一个数量级，因此地层有效介电常数测量值对地层水含量是灵敏的。和地层总孔隙度结合直接地确定含水饱和度是可能做到的，因此避免了使用阿尔奇公式和电阻率测量结果时涉及需要用胶结指数和饱和度指数带来的困难。介电测井解释需要建立各种介电特征和岩石组成成分间关系。在1GHz频率条件下（Seleznev等人，2004年）经验性复杂折射指数模型展示出良好的可行性。在用盐水饱和的不含粘土岩石中低频情况下介电常数不仅强烈地受盐水体积含量影响，而且也受岩石结构的强烈影响。这种依赖关系限制了简单经验关系的适用范围，并且要求开发一种能够适当描逆结构非常不同的岩石，例如碳酸盐岩的介电弥散及电导率弥散的综合弥散模型。 近似地世界上石油的一半是采于灰石储集层和白云岩储层（Dickey，1979年）。碳酸盐岩油藏含有世界地下石油剩余储量的60％以上。巨型碳酸盐岩油田，特别是中东的油田？预计21世纪在世界石油产量中处于支配地位。结构参数，例如阿尔奇公式胶结指数变化大的碳酸盐岩地层的介电测井解释，容易应用结构弥散模型。本文中，我们采用这样的模型，以致于以多频测量结果能计算岩石结构影响并且和实验数据相匹配。我们也推荐了解释方法，它能提供冲洗带电阻率、含水饱和度及阿尔奇公式胶结指数。     

低频条件下岩石孔隙水电容特性的蒸发实验研究

从束缚水、自由水的介电特性差异出发,测量相同几何尺寸岩样的电容值反映其介电特性,研究了一种新的岩石孔隙水分布状态分析方法并定量确定束缚水饱和度。采用岩石质量-电性参数自动测量系统实现岩石不同质量和不同频率下电容数据的连续采样。扫频测量的实验结果表明,100×103 Hz是一个比较理想的测量频率,该频率下水的分布状态对岩石电容-含水饱和度曲线的形态影响较大,岩石电容-含水饱和度曲线呈N形分布。将N形曲线上、下拐点作为吸附水、束缚水含量分界线来得到岩石吸附水和束缚水的饱和度。实验结果表明,采用介电实验研究岩石孔隙水分布状态的方法可行,并证明了岩石吸附水、微毛细管水和自由水具有不同的介电特性,且受测量频率和含水饱和度的影响。     

大功率超声波近井处理无机垢堵塞技术

利用自主研制的波场采油动态模拟室内实验装置和人工岩心碳酸钙无机垢堵塞样品,系统研究了超声波解除岩心无机结垢堵塞的整体效果及关键的波场参数、工艺参数和岩心物性参数对解堵效果的影响规律,同时系统分析了超声波解堵的主要动力学机制,在此基础上利用自主研制的新型超大功率超声波矿场施工装置进行了现场试验.研究结果表明,挟能器频率、换能器功率、超声处理时间、岩心初始渗透牢均影响超声波解堵效果.换能器频率、功率增加,解堵效果变好;累计处理时间80～120 min解堵效果最好;岩心初始渗透率越高解堵效果越好.经陕北低渗油藏与大庆油田矿场试验验证,增产增注效果显著,证实了室内实验结果的合理性.图6表2参18     

水驱黏土微粒迁移理论及作用

大部分砂岩油藏中皆含有少量的黏土成分,采用水驱技术会导致黏土微粒迁移。黏土表面电荷、扩散双电层结构、黏土矿物类型、可交换阳离子、矿化度、水膜等皆为导致黏土微粒迁移的重要因素。经过对黏土微粒迁移文献分析可知,黏土微粒只有在黏土微粒浓度大于孔隙壁面的临界微粒滞留浓度时,才会迁移,以此推导论证Bedrikovetsky临界滞留浓度模型。尽管黏土微粒迁移与黏土膨胀的结果都会带来地层伤害,但根据微粒迁移理论分析可知,微粒迁移改善了地层孔隙度和渗透率的非均质性,改变油层润湿性,封堵高渗透层,提高洗油效率,降低含水率。因此,适当控制好黏土微粒迁移量,能提高原油采收率。     

石油物探钻机转速自动调节装置

随着钻井工况和钻机载荷的变化 ,物探钻机发动机的转速波动很大 ,而完全靠人工控制发动机节气门的开度已不能适应发动机转速大幅度频繁波动的要求 ,对此 ,研制了用于石油物探钻机的转速自动调节装置。这种装置利用发动机的点火信号实施发动机转速的自动控制。首先 ,将点火信号通过整形电路变成频率信号 ,然后进行频压变换 ,其电压与转速为线性关系 ,该电压与设定电压 (预期转速 )相比较 ,用比较输出的状态控制伺服电动机的转动自动控制节气门的开度 ,从而实现转速控制。华北油田物探公司两个地震队试用取得了满意的效果     

泥质砂岩中束缚水的介电特性

泥质砂岩“双水模型”只讨论了束缚水和自由水在导电响应上的差异,本文对泥质砂岩介电响应机理进行分析,说明了粘土颗粒表面的束缚水和自由水在介电响应上的差异。另外,在大量实验测量的基础上,计算得到束缚水的复介电常数值,结果表明理论分析和实验测量是一致的。利用上述理论和实验研究结果修正了电磁波测井的解释模型,并将该模型用于实际测井资料解释,求得的冲洗带残余油饱和度(S_(or))和束缚水饱和度(S_(wirr))与取心分析值符合较好。依据上述理论和实验分析提出了电磁波测井资料解释应用的新领域。     

Inhibition of plasticizer migration from packaging to foods during microwave heating by controlling the esterified starch film structure

Plasticizer migration from packaging films to foods can raise health concerns especially when foods are heated in microwaves with their packaging. To inhibit the plasticizer migration, starch-based films were prepared by controlling the micro-structure of esterified starch films with various degrees of substitution (DS), and diethyl phthalate (DEP) was added. The DEP migration after microwave heating, and the interaction between the plasticizer and starch molecules, and the aggregation structure of starch films at nanometer scales were investigated. The data showed that the esterified starch film with the DS of 1.81 had the lowest amount of DEP migration compared with other films (DS 1.17, 1.42, 2.27, and 2.61). The starch films with higher DS showed increased X-ray scattering intensity with a B-type starch scattering pattern. The high DS enhanced the order and compactness in both crystalline and amorphous regions of the film, and increased the distance between crystalline regions. In addition to the change in its aggregation structure, the increase of DS weakened intermolecular interaction between starch molecules, but increased the interaction between DEP and starch–ester molecules. Our approach offered a balance of structural integrity and intermolecular interaction. Plasticizer migration was successfully reduced by controlling the DS of esterified starch film with a strong interaction between DEP and starch–ester molecules, better organized crystalline structure, and more compact and better ordered micro-region aggregation structures with suitable distance between them.     

Presence of indicator bacteria,Salmonella and diarrheagenic Escherichia coli pathotypes on mung bean sprouts from public markets in Pachuca,Mexico

Coliform bacteria (CB), fecal coliforms (FC), Escherichia coli, diarrheagenic E. coli pathotypes (DEP) and Salmonella frequencies were determined for mung bean (Vigna radiata) sprouts. One hundred sprout samples were collected from markets in Pachuca, Hidalgo state, Mexico. Of these samples, 100% were positive for CB, 98% for FC, 95% for E. coli, 10% for DEP and 5% for Salmonella. Identified DEP included enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC) and Shiga toxin-producing E. coli (STEC). The ETEC and EIEC were each isolated from 2% of samples, and the STEC from 6% of samples. No E. coli O157:H7 were detected in any STEC-positive samples. Positive correlations were observed between FC and E. coli and between E. coli and DEP. A negative correlation occurred between CB and DEP, and between CB and Salmonella. Neither FC nor E. coli correlated with Salmonella presence in the sprout samples. This is the first report of ETEC, EIEC and STEC isolated from sprouts in Mexico and the first report of Salmonella isolation from mung bean in Mexico. Mung bean sprouts are very probably an important factor contributing to the endemicity of ETEC, EIEC and STEC and Salmonella-related gastroenteritis in Mexico.     

Studies on effect of incorporation of BDNPF/A on burning rates of RDX/AP/AI filled CMDB propellants

Abstract

This paper reports the effect of replacement of non -energetic plasticizer diethyl phthalate (DEP) by nitroplasticizer [1:1 mixture of bis (2,2 dinitro propyl) formal (BDNPF) and bis (2,2 dinitro propyl) acetal (BDNPA)] on burning rates and Isp of nitramine (RDX) / ammonium perchlorate (AP) based composite modified double base (CMDB) propellants. Addition of BDNPF/A led to overall 9–46% increase in burning rates, as well as gain in Isp to the order of 5–10 s in both the systems. Inclusion of copper chromite (C.C.) led to further improvement in burning rates. A typical aluminized (17.5%)- ecofriendly RDX (12.5%)-CMDB formulation gave burning rates of the order of 8–22 mm/s in the pressure range of 2.9–10.8 MPa with Isp (theoretical) of 264 s. Aluminized AP-CMDB propellant with low pressure combustion limit of 1.9 MPa and burning rates of 15–31 mm/s was also realized during this work. Superior oxygen balance and heat of formation of BDNPF/A compared to DEP appear to play contributory role in this regard. Heat feed back from intensified combustion near the deflagrating propellant surface may be facilitating the decomposition of condensed phase. This is clearly brought out from estimated activation energy values for BDNPF/A plasticized RDX propellants.     

无机硅改性羧甲基淀粉钠降滤失剂的研制及其性能

在合成羧甲基淀粉钠(SCMS)的过程中引入水溶性硅酸钠对其进行改性,合成了硅改性的SCMS降滤失剂(Si-SCMS)。XRD和FTIR表征结果显示,产物中有Si—H基团生成,表明无机硅酸钠参与反应生成了有机硅化合物;经TG-DTA分析发现,Si-SCMS降滤失剂的热分解温度为220℃。将Si-SCMS配入钻井液,试样在150℃热滚后的失水量仅为15.2mL,与SCMS降滤失剂相比,抗温性能显著提高;且Si-SCMS降滤失剂的降滤失性能也得到提高。同时探讨了Si-SCMS降滤失剂抗温性能提高的原因,认为无机硅酸钠的引入抑制了SCMS分子的降解,同时改性后Si—H基团的生成使得高聚物分子链的刚性增强,从而导致其抗温性能提高。     

中国石油与壳牌公司长北合作区块天然气地面集输工艺

长庆油田长北合作区是中国石油与英国壳牌公司在中国陆上规模最大的合作开发项目,其地面集输工艺的设计充分吸收了国内外的成熟做法,并依照壳牌公司的《设计和工程实施规范》（DEP）标准,形成了独特的开发模式。为此,详细介绍了长北合作区地面集输系统的构成和工艺流程,并与国内部分典型气田的集输工艺进行了对比,从布站模式、天然气处理工艺、变压运行工艺、气液混输工艺、井口湿气计量工艺、内防腐工艺、分段清管工艺、清管球集中回收工艺和天然气水合物抑制工艺等方面对长北合作区地面集输工艺进行了分析说明,结合生产运行情况,总结出了长北合作区地面集输工艺的特点--“井丛集气、开工加热、中压集输、气液混输、井口计量、移动分离、定期测试、仪表保护、智能清管、一级布站、枝状管网、低温分离、集中增压”。     

羧甲基纤维素-g-2-丙烯酰胺基-2-甲基丙磺酸高吸水树脂的吸水与保水性能

以羧甲基纤维素(CMC)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为原料、过硫酸铵为引发剂、N,N′-亚甲基双丙烯酰胺为交联剂,采用微波辐射法制备了耐盐性高吸水性树脂CMC-g-PAMPS。考察了无机盐溶液的浓度、金属离子价态、溶液pH和单体总含量等因素对CMC-g-PAMPS树脂吸水倍率的影响,并对其吸水速率和保水性能进行了研究。实验结果表明,吸水倍率随无机盐溶液浓度的增加而减小;在不同价态金属离子盐溶液中,吸水倍率大小的顺序为:NaCl>CaCl2>AlCl3;在相同价态的金属阳离子盐溶液中,CMC-g-PAMPS树脂的吸水能力接近;CMC-g-PAMPS树脂在pH=4～8内能保持较高吸水倍率。     

氯离子选择电极法测定原油中的总氯含量

建立了原油中无机氯及总氯含量的检测方法。利用氯离子选择性电极法,辅以高剪切乳化分散法和氧弹燃烧法分别测定原油中的无机氯及总氯含量。结果表明：氯离子选择性电极法测定氯离子的线性拟合公式为E=-17.11+54.37lgC,相关系数R为0.9999,线性范围为6.9×10-6 ~ 1.0 mol/L,实测检测下限为6.9×10-6 mol/L,能够达到油田采出原油中无机氯及总氯含量的检测要求。无机氯提取到水相中的提取条件为80 ℃条件下,100 mg/L的NaOH溶液与原油的提取比为1 000倍,11 000 r/min高剪切分散4 min。原油氧弹燃烧将其中的有机氯离子化的条件为充氧压力2.5 MPa 条件下燃烧,气体用0.5 mol/L的Na2CO3溶液吸收30 min。实验结果表明,无机氯及总氯的标加回收率为94%~102%,满足油田生产中原油无机氯、有机氯和总氯的快速准确检测。     

Performance of laboratories in speciation analysis in seafood – Case of methylmercury and inorganic arsenic

The international measurement evaluation program (IMEP) has together with the European Reference Laboratory for Heavy Metals in Feed and Food (EU-RL-HM) carried out two interlaboratory comparisons (ILC) in 2010 on the measurement of trace metals, as well as methylmercury and inorganic arsenic in seafood. In IMEP-109 only EU National Reference Laboratories (NRL) took part, while IMEP-30 was open to all laboratories. In this article only methylmercury and inorganic arsenic analysis will be discussed, as these appear generally to be more problematic measurands. They are also particularly interesting to legislators, as no maximum limits have been set yet for them in European legislation. The aim of the two ILCs was to produce more information to help tackling this issue. The results of the two exercises were pooled together, evaluated, and compared with former ILC projects for methylmercury and inorganic arsenic analysis. Results for inorganic arsenic were spread, but not method dependant. The measurand seems to be difficult to analyse in this matrix and possible method issues were identified. Methylmercury results were satisfactory, but not many laboratories perform this type of analysis because it is generally believed that specific instrumentation is needed. As an answer to this presumption, alternatives are suggested.     

长岭断陷无机成因天然气的判别与分布特征

通过对松辽盆地长岭断陷烷烃气和CO2碳同位素资料的分析,认为该地区存在无机成因天然气。烃类气体中具有重碳同位素异常(δ13 C1>-30‰)和负碳同位素系序(δ13 C1>δ13 C2>δ13 C3>δ13 C4)的同位素分布特征,CO2碳同位素分布在-4.63‰～-16.7‰,部分天然气表现出无机成因烃类气体的特点。3 He/4 He值为0.88Ra,指示有幔源氦的存在,说明该区天然气可能是壳幔混源。长岭断陷天然气藏中不仅无机成因烷烃气由北向南逐渐减少,且幔源CO2也表现出从西北向东南含量明显减少,与区域构造、断裂走向和火山岩密切相关等与无机成因烷烃气相似的分布特征。