抽油机井化学防蜡方式优化

原油中所含的石蜡,它能够形成大晶块蜡,是造成蜡沉积而导致油井堵塞的主要原因。目前国内油田大多采用化学药剂清、防蜡技术,热力清蜡等技术。清防蜡作为油井日常维护的重要工作耗费了大量的人力物力。化学药剂清、防蜡作为油井最主要的清防蜡措施,对于油井的清防蜡效果起着至关重要的作用。因此,优化油井加药方式、提高化学清防蜡的措施效果,对于油井的正常生产将起着积极的指导意义。     

加蓬A油田原油物性研究及防蜡剂评价

 测定了加蓬A油田6口油井油样的蜡含量、倾点、黏度、析蜡点和屈服值等指标.通过测定这些影响原油流变性的关键指标,得出,加蓬A油田的原油为高含蜡、高倾点原油,蜡组分中高碳重质组分权重很大;蜡含量高达34.04%以上,平均倾点为28℃,平均析蜡点为47.5℃,平均屈服值为159.11Pa.防蜡剂FLO-1在加量为100×10^-4时,对TST-B09H井油样的防蜡率可以达到91.86％,对于NZOB-Z05H井油样可以达到81.47%.这为加蓬原油的开采、运输、加工等提供了有效的基础数据,也为油井现场清防蜡工作,特别是对化学清防蜡剂的筛选提供直接的理论支持.     

轻质油蜡样分析和固体防蜡剂的研制

针对我国西部部分油田油井结蜡而存在的生产实际问题,现场采集了油井的结蜡样品,运用X射线粉末衍射、红外光谱和扫描电镜等对采集蜡样进行了分析研究,得出蜡样中含有芳烃、正构烷烃和沥青质等相对大的颗粒物质。根据蜡样的特点,在室内对固体防蜡剂的主剂和助剂等进行了优选和复配,最终研制出了适用于轻质油油井防蜡用的固体防蜡剂。运用自制的实验装置对该固体防蜡剂在原油中的各种性能进行了室内研究,得出该固体防蜡剂的溶解速度分别为1.094mg/L?min-1（50℃）、2.112mg/L?min-1（55℃）、4.925mg/L?min-1（60℃）时,防蜡效果较好,当其达到一定浓度时,防蜡率超过50%。并通过评价结果分析研究了防蜡剂产生效果的机理,同时得出了在油田现场实际施工时要注意井深情况的结论。     

油基清蜡剂性能研究

为了研制出溶蜡性能好、密度高的油基清蜡剂 ,在考察了 2 3种溶剂后发现 ,单一的油基溶剂都难以达到清蜡剂的要求。但研究发现 ,所收集的高密度的重溶剂油和低密度的轻质油在溶蜡性能方面具有协同效应。以体积分数为 0 .6的轻质油和体积分数为 0 .4的重溶剂油 2 # 组成的油基清蜡剂 ,其密度达 0 .97g/cm3 ,溶蜡速率达 0 .0 37g/min ,材料成本低于 2 80 0元 /t。制备这种油基清蜡剂的乳状液时可选择氢氧化钠部分中和油酸作乳化剂。当乳化剂的质量分数为 0 0 1时 ,所配成的乳状液的稳定时间可达 2 4h。     

微生物清防蜡技术研究及应用

利用从大庆含蜡原油中分离、纯化得到的微生物清防蜡菌种和高产表活剂菌种,经鉴定清防蜡菌种和高产表活剂菌种均为芽孢杆菌属.以菌种对固体石蜡的降解率为指标,按照不同的比例将清防蜡菌种和高产表活剂菌种混合接种.当清防蜡菌种与高产表活剂菌种的复配比例是5∶3时,培养7d后,清蜡率达到59%,防蜡率达到57.4%,原油粘度降粘率为44.7%,原油凝固点降低了3.4℃,培养液表面张力降低46.5%.采用微生物清防蜡技术对大庆外围榆树林油田的3口井进行现场试验,井12-36日产油增长41.2%,洗井周期由40d延长至149d,减少洗井次数4次;井13-39日产油增长33.3%,洗井周期由45d延长至158d,减少洗井次数5次;井14-43日产油增长37.5%,洗井周期由30d延长至122d,减少洗井次数5次.     

油基清蜡剂性能研究

为了研制出溶蜡性能好、密度高的油基清蜡剂,在考察了23种溶剂后发现,单一的油基溶剂都难以达到清蜡剂的要求。但研究发现,所收集的高密度的重溶剂油和低密度的轻质油在溶蜡性能方面具有协同效应。以体积分数为0.6的轻质油和体积分数为0.4的重溶剂油2^#组成的油基清蜡剂,其密度达0.97g／cm^3,溶蜡速率达0.037g／min,材料成本低于2800元／t。制备这种油基清蜡剂的乳状液时可选择氢氧化钠部分中和油酸作乳化剂。当乳化剂的质量分数为0．01时,所配成的乳状液的稳定时间可达24h。     

固体药剂清防蜡技术应用

本文简单论述了影响油井结蜡的主要因素和油井清防蜡常用技术,并重点介绍了固体药剂清防蜡技术的原理、结构。本文调查、分析了油井清防蜡现状,筛选出产量较低、井筒液体温度低、原油粘度低、含蜡量高的部分油井在现场进行了固体药剂清防蜡实验。通过具体的实验应用,对效果进行了分析,与常规热洗、井口加药相比较,得出了相关结论。     

剪切和降凝剂作用对含蜡原油流变性的影响

为了研究管输过程中降凝剂及管流的剪切作用对含蜡原油的流变性的影响,在不同剪切速率下对加降粘剂与未加降粘剂的原油进行了对比实验.研究表明,降凝剂作用和剪切作用都能使蜡晶的形状、大小以及结构等发生变化从而影响原油的流变性能,剪切作用和降凝剂作用对含蜡原油的流变性存在交互性影响.油样凝点由加剂前的16℃降低到加剂后的-10℃,降低了26℃;未加剂油样反常点温度为30℃,加剂油样的反常温度为26℃,降低了4℃;加剂前后油样析蜡点的温度基本没有变化;相同温度相同剪切速率下所测两油样粘度值差别比较大,总体上未加剂油样的粘度比加剂油样的粘度低.剪切作用对未加剂油样流变性能的影响明显大于对加剂原油流变性的影响;剪切作用对加剂原油流变性能的影响程度跟剪切速率和剪切温度有很大关系;加剂原油粘度下降幅度随剪切作用的增强而逐渐减小,当剪切作用超过一定范围时,对加剂原油粘度将不再产生影响.     

基于激光法的含气高含蜡原油熔蜡规律

为获得高含蜡原油溶蜡规律,同时进一步探索含气原油溶蜡特征,采用了显微观测法和激光法进行实验。首先通过显微观测法获得了升温过程中蜡晶变化特征;其次采用激光法对脱气原油进行了测试并与显微观测法进行对比联系,验证了激光法的可靠性;最后采用基于Beer-Lambert定律的激光衰减曲线获得了含气原油溶蜡点以及升温过程中蜡含量、平均等积圆平均直径和颗粒宽度系数等参数的变化特征。实验结果表明:脱气原油蜡晶升温溶解过程以凝固点为界可划分为慢速和快速两个溶解阶段;原油溶蜡特征与不同碳数的正链烷烃熔点有着密切联系,质量累积计分数曲线上97%所对应的烷烃熔点接近或高于实测原油溶蜡点,质量累积计分数曲线相近的原油溶蜡点相同;含气原油凝固点比地面条件下脱气原油低约7℃,溶蜡点低约2. 5℃,并且凝固点后含蜡量以平均0. 15%/℃的快速下降,后稳定在0. 076～0. 087%/℃。该研究可以预估和评价不同温度、压力下原油黏度以及清蜡速率,避免保守设计带来的经济损失。     

析蜡不可逆性对低渗高凝油流动性及水驱效果的影响

高凝油析蜡具有不可逆性,对注水开发及油藏后期进一步提高采收率造成影响。系统对比降温和升温模式下高凝油析蜡-溶蜡行为、黏度、流变性、油相渗流能力及水驱效果。结果表明：某高凝油溶蜡点为71.5℃,明显高于其析蜡点的62.3℃,存在不可逆性;温度高于溶蜡点时,降温和升温模式中原油黏度值基本相同,水驱采收率相当;温度介于溶蜡点和析蜡点时,降温模式中原油未析蜡,黏度小,为牛顿流体,无渗流启动压力,水驱采收率较高(超过60%);升温模式中蜡晶未完全溶解,黏度高,为非牛顿流体,存在启动压力,水驱采收率明显降低(小于50%),不可逆性影响显著;对于已受冷伤害的高凝油油藏,注热小幅度提高油藏温度是不够的,必须达到溶蜡点以上,否则水驱效果会明显变差。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with