利用临界粘壁温度指导高含水油田不加热集输现场试验

随着油田进入高含水开发后期，采出液含水率不断升高，凝固点、黏度随之降低。经现场实验，高含水油井可实现低于原油凝固点集输，凝固点已经不适宜作为指导集输温度的唯一条件。为了在安全生产的前提下最大限度地降低集油温度，通过室内试验明确某油田原油粘壁特性，并根据所得的结果指导现场开展不加热集输试验，取得了试验区掺水量下降90%以上、回压控制在0.8 MPa内的效果。试验结果表明，可以利用临界粘壁温度指导高含水油田采油井不加热集输，为油田低能耗生产提供了依据。     

海安油田高凝原油流变性试验研究

海安油田为高含蜡、高凝点原油。为解决原油集输问题,进行了原油析蜡试验、比热容试验、黏度试验和破乳试验。根据试验结果,结合集输工艺论证,确定海安油田采用热输工艺进行管线输送原油,解决了海安油田高凝油集输问题。     

不同特性油田的油气集输工艺技术

对于灰岩油田（如任丘油田），根据油井产量高和油温高以及含水率上升快的特点，初期采用疏井网、大管线和单管集输流程；随着井网加密和第三系砂岩油田的开发，单井产量降低，对油气集输系统逐步调整为单井→计量站→集中处理站的两级布站流程；当原油含水达到70％～90％时，为减轻集输和处理系统的负荷，则又采取不加热输送、磁处理脱水、高效破乳剂、多功能合一设备、集输处理站集中供热等技术。对于严寒地区油田（如阿尔善油田），则采用以水力活塞泵采油的双管集输流程，它以净化油为动力液，升温至80～85℃，高压输至计配站和井口，经井下动力液泵采出原油并和动力液混输至计配站计量后输至大站处理。该流程运行8年，经受了-40℃严寒的考验。对于沙漠油田（如鄯善、温米和丘陵油田），则采用井口→选井站→联合站的一级半布站流程；较远区块采用井口→选井站→中心计量站→联合站的两级布站流程。处理工艺采用中压多级分离稳压工艺和合一设备。对于小断块低渗透油田，则根据具体条件，采用单管不加热密闭集输流程或双管回掺流程或三管伴热流程或双管环形伴热流程或单管电伴热保温流程。     

高凝油集输及其处理工艺研究

沈阳油田高凝油集输采用二级布站，充分利用地层能量，提高油井回压．实现油气密闭混输的办法。油气集辅半径l～3．5km，井口回压1．0～1．2MPa。集输混程主要有：原油凝固点大于45℃的油井．大部分采用水力活塞泵采油集输，其动力液来自本区块自产的高凝油；闭式热水循环集输工艺，其循环介质采用热污水，闭式循环自成体系，介质入井压力低，这种流程既可提高污水利用率，又可节能，对低产的边远井可随时掺水输送；投球输送工艺．适用常温运行，当原油凝固点为28～36℃，气油叱大干40m^3／t时，可采用此集输流程，但流程较复杂。油气处理工艺，沈阳油田采用一级油．气、水三相分离与加热，二级热化学脱水。高凝油稳定工艺，采用微正压闪蒸工艺，原油稳定深度控制在C5组分拔出量不超过稳定前原油中C6组分总量的5％；天然气处理采用二甘醇吸收脱水工艺．可进一步提高天然气干度；轻烃回收装置采用氨为冷冻剂，配以膨胀机和分离机，能回收100％轻质油和50%的液化气。     

大庆油田南一区掺低温水集输流程

老油田开发进入高含水开采期，油井产液量、含水率大幅度增加，油井出油温度不断升高，由于降粘剂、防蜡剂的采用，防腐保温技术的进步，集输温度普遍提高。为了降低原油集输过程中的能耗，结合大庆油田南一区原油物性，地理条件和生产现状，开展了掺低温水原油集输工艺试验，取得显著的节能效果。着重介绍该区原油掺水保温流程概况，掺水温度的优选，掺低温水工艺取得的试验成果和效益。     

北小湖高凝原油油田集输方案初探

根据北小湖油田地处边远、含油面积小、原油高凝性等特点,以开发建设的经济性和工程技术的适用性为基础,阐述了井口加热密闭集输、伴热保温密闭集输和井口掺热水保温集输3种不同集输方案,提出了三塘湖盆地分散小区块油田建设建议.     

北小湖高凝原油田集输方案初探

根据北小湖油田地处边远、含油面积小、原油高凝性等特点,以开发建设的经济性和工程技术的适用性为基础,阐述了井口加热密闭集输、伴热保温密闭集输和井口掺热水保温集输3种不同集输方案,提出了三塘湖盆地分散小区块油田建设建议。     

电加热集输管道时控周期及能耗的研究

电加热集输控制方式有温控电伴热与时控电伴热两种，目前现场采用温控电伴热——点控温的方法，通过温控器限定温度传感器处的最高温度和最低温度，从而控制电热带的加热时间和停止加热时间。此方法缺点是在温度控制器失灵时，可能造成电加热带停止加热或一直保持加热状态，造成管线阻塞或油温过高，电能损耗过大。针对这种集输状况，将电加热集输控制方式改为时控电伴热，通过确定时控周期，控制管道的加热状态。相对于点控温，时控温不但施工简便，而且节约了能耗，同时矿场试验也证明，时控电伴热具有显著的经济效益和良好的应用前景。     

油田站外单管集油辅助工艺对比

为了解决部分油井无法单管输送的问题,采用PIPESIM模拟软件对不同含水率、不同集输半径和不同产液量油井的集输管线进行计算分析,同时结合各油田单管集输设计经验,得出中质原油站外系统单管集油工艺改造的技术界限,而对于达不到技术界限的油井,可以通过辅助措施实现单管集油,通过对比电磁加热器、空气源热泵、管道内置电伴热、井口气电加热器、油井保温隔热油管、地热、太阳能光热技术及井口加药等单管辅助措施的原理及工艺特点,最终确定在不同工况条件下的辅助单管集输措施,为油田站外单管集输工艺选择和优化提供了理论依据。     

关于原油集输改用油田采出污水伴热的讨论

从技术和经济两方面讨论了原油集输清水伴热改用油田采出污水伴热的可行性，指出原油集输系统改用油田采出污水伴热不仅可行，而且经济效益显著，技术可靠。     

LOW TEMPERATURE FLOW CHARACTERISTICS OF SOME WAXY CRUDE OILS IN RELATION TO THEIR COMPOSITION : PART II EFFECT OF WAX COMPOSITION AND CONCENTRATION ON THE DEW AXED CRUDE OILS WITH / WITHOUT ADDITIVES

ABSTRACT

In this part of the work the effect of wax concentrations on the rheologica! properties of the dewaxed Duliajan (Assam) and Lingaia crude oils have been studied. The dewaxing of the crude oil was done by removing n-paraffins from the crude oil by urea adduction. The urea adducted n-paraffins concentrate-the wax- was characterized by its carbon number distribution. The urea non adducted oil portion - the denormalized crude oil (DNO)- was characterized for its pour point. The wax in different concentration was then added in the DNO and the change in the rheological properties like pour point, yield stress and plastic viscosity were studied using a Haake Rota Viscometer. The effect of carbon number distribution, i.e. the composition of the wax, on these rheological properties was also investigated. Four different commercial pour point depressanl additives have been used to study their effects on the pour point, yield stress and plastic viscosity of the reconstituted (wax mixed DNO) crude oils.

From this study it has been found that wax concentration and its composition are primarily responsible for the variation in the pour point of the DNO, and the DNO composition has a small effect. However, as seen in the Part I of this paper, the response of the pour point depressant additive in effecting the change in the pour point is primarily governed by the composition of the DNO. The additives have shown better response in the DNO having more aromatic concentrate, as has been found in the case of Duliajan (Assam) DNO.     

LOW TEMPERATURE FLOW CHARACTERISTICS OF SOME WAXY CRUDE OILS IN RELATION TO THEIR COMPOSITION : PART II EFFECT OF WAX COMPOSITION AND CONCENTRATION ON THE DEW AXED CRUDE OILS WITH / WITHOUT ADDITIVES

In this part of the work the effect of wax concentrations on the rheologica! properties of the dewaxed Duliajan (Assam) and Lingaia crude oils have been studied. The dewaxing of the crude oil was done by removing n-paraffins from the crude oil by urea adduction. The urea adducted n-paraffins concentrate-the wax- was characterized by its carbon number distribution. The urea non adducted oil portion - the denormalized crude oil (DNO)- was characterized for its pour point. The wax in different concentration was then added in the DNO and the change in the rheological properties like pour point, yield stress and plastic viscosity were studied using a Haake Rota Viscometer. The effect of carbon number distribution, i.e. the composition of the wax, on these rheological properties was also investigated. Four different commercial pour point depressanl additives have been used to study their effects on the pour point, yield stress and plastic viscosity of the reconstituted (wax mixed DNO) crude oils.

From this study it has been found that wax concentration and its composition are primarily responsible for the variation in the pour point of the DNO, and the DNO composition has a small effect. However, as seen in the Part I of this paper, the response of the pour point depressant additive in effecting the change in the pour point is primarily governed by the composition of the DNO. The additives have shown better response in the DNO having more aromatic concentrate, as has been found in the case of Duliajan (Assam) DNO.     

阴离子聚合物St-OMA的合成和应用

采用阴离子聚合法合成苯乙烯（Styrene）-甲基丙烯酸十八酯（Octadecyl methyl acrylate）的二元共聚物St-OMA,评价了不同聚合条件下的聚合物对苏丹原油的降凝效果。通过偏光显微镜和图片处理软件对加剂前后原油中的蜡晶形态和分布进行微观分析,原油中蜡晶由大量片状、针状形态改变为颗粒状,蜡晶尺寸较小,蜡晶间也密实,分散得更细更匀称。这表明降凝剂的加入确实改变了原油中蜡的结晶形态,使析出的蜡晶尺寸变小变密,从而改善了原油的流动性,降低了原油的凝点。     

聚合物型原油降凝剂的结晶性能研究

摘要: 采用红外光谱仪、核磁共振波谱仪对聚合物的合成特征基团进行了表征，并采用X射线衍射仪对不同型号蜡及降凝剂的结晶性能进行了分析测试，结果表明蜡晶与聚合物的结晶性能密切相关，结晶度不同，蜡晶分散效果不同，对原油降凝性能也就有所区别，当两者结晶性能状态匹配时蜡晶分散效果变好，降凝降粘性能最佳，并通过考察原油体系热性能和低温流动性能进行了证实。     

降凝剂对中哈管输阿拉山口口岸多蜡原油流变性的影响

筛选了适合改善中哈管输阿拉山口口岸含蜡原油流变性的降凝剂,考察了加剂前后全黏温曲线的变化及重复加热、高速剪切对原油黏度和凝点的影响,并考察了静置稳定性。实验结果表明：在60 ℃处理温度下加入50 g/g乙烯-醋酸乙烯酯和丙烯酸接枝共聚物作为降凝剂,可使原油的凝点降低10~20 ℃以上,黏度、反常点、屈服值均有明显降低;重复加热温度低于60 ℃,随温度的降低原油改性效果变差;高速剪切对降凝剂降凝效果的影响与温度有直接关系,在析蜡高峰区温度附近降凝效果恶化严重;降凝剂对原油的静置稳定性表现较好。     

A new experimental investigation on upgrading of waxy crude oils by methacrylate polymers

Several methods have been used to reduce problems caused by wax precipitation during the production and/or transportation of waxy crude oil. Polymers are used to improve pour point and rheological behavior of waxy crude oils. In this work, the influence of the polymer inhibitors such as methacrylate polymers, as wax inhibitor, with different range of molecular weight and alkyl side chain carbons on the rheological behavior and pour point of two Iranian waxy crude oils were evaluated. Two Iranian waxy crude oils were selected on the basis of wax and asphaltene contents. The rheological behavior of these crude oils in absence and in presence of methacrylate polymer was studied. The rheological data cover the temperature range of–1 to 12°C. The results indicated that the performance of methacrylate polymer was dependent on the molecular weight, alkyl side chain carbons and the asphaltene content of crude oil. Methacrylate polymers with longer alkyl side chains than 18 carbons would perform best as wax inhibitors in two cases. Also, for crude oil with low asphaltene, higher molecular weight methacrylate polymer is the best flow improver and lower molecular weight methacrylate polymer showed good efficiency for crude oil with high asphaltene content.     

潍北高凝点原油降凝降黏剂的研制

实验室自制的三元共聚物AMV-22与EVA复配,添加SLA-107作助剂,制备适用于胜利油田潍北区块高凝点原油的降凝剂AMVES。实验考察了该降凝剂对原油的降凝降黏效果。DSC热分析结果表明,AMVES加量为1000 mg/L时,可使原油凝点从48℃降低到37℃,析蜡点降低2℃。流变性曲线表明原油的剪切稀释作用随温度升高显著增强,当剪切速率大于100 s^-1后黏度基本不变,降凝剂可以大幅降低启动原油的屈服应力。偏光显微镜图显示原油温度越低,蜡晶网状结构越致密,交联度强,黏度大,流动性差;加AMVES之后原油中蜡晶变为团簇状颗粒,原油的流动性增强。由此可见降凝剂AMVES作用于蜡晶使其三维网状结构破坏,从而有效降低原油凝点和黏度。     

高凝原油降凝剂的制备及其降凝机理研究

 由丙烯酸十八酯、马来酸酐和醋酸乙烯酯三元共聚物的胺解改性物（MAVA）和乙烯-醋酸乙烯酯的共聚物（EVA）为原料,通过复配制备了一种高凝原油降凝剂(PPD),并对其降凝效果和降凝机理进行了研究。结果表明,所制备的高凝原油降凝剂对凝点为43℃的胜利原油具有明显的降凝效果,在加剂量为400?g/g时,原油的凝点降低了11℃;由原油中的沥青质和胶质所形成的聚集体结构是原油的蜡晶成核剂,降凝剂可以同原油中的沥青质和胶质结合形成新的沥青质-降凝剂-胶质聚集体结构,该聚集体结构作为加剂原油的蜡晶成核剂,可以改变蜡的结晶方式,延缓蜡晶的析出速率,大幅地降低了原油的凝点。     

高凝油渗流特性的实验研究

选择２块人造岩心和２块取自于沈北油田的天然岩心，分别在不同条件下饱和地层水，进行了油驱水实验，实验用油具有较高的含蜡量和凝固点；由实验观察可知，温度是决定高凝油渗流特性的决定性因素，当温度高于反常点时，原油呈牛顿流体，粘度在整个渗流过过程不变，反之则呈非牛顿流体，粘度对温度非常敏感，随温度降低，原油粘度升高，油相渗透率和驱油效率降低，在析蜡前后，变化尤为明显；高凝油的渗流特征还受压力梯度的影响，最     

The Effect of Commercial Additives as Pour Point Depressants for Fuel Oils

When the crude oil temperature goes below the pour point value wax crystals will come out of solution and tend to plug lines and filters. Additionally, the wax deposited in tanks decreases the storage capacity. In general, wax deposition can cause problems in production, storage, transportation, and consumption. Pretreatment of the crude oil with flow improver or pour point depressants has received the greatest acceptance due to its simplicity and economy. Four commercial additives were evaluated as pour point depressant for fuel oils. The structures of the commercial additives were confirmed by FTIR spectra. The results indicate that the n-alkanes carbon distributions display an obvious normal distribution in fuel oils. The distributions of high carbon n-alkanes are all broad so that wax crystals not precipitate in fuel oil at low temperatures is good. These commercial additives were tested as pour point depressants for fuel oil. The obtained data revealed that the prepared compounds depress the pour point of the fuel oil successfully. Comparison of structures of wax crystals in untreated and treated fuel oil was also done by photomicrographic analysis.