任京线正反输运行长期不清管条件下的结蜡规律

针对任京输油管道正反输运行长期不清管的情况,通过比较现有结蜡模型的优缺点．建立了适用于大庆冀东混合原油的结蜡模型;考虑结蜡过程的周期性和时效性,研究了任京线的结蜡规律;利用两次任京线改线工程的现场实测结蜡厚度进行了验证,实测值与预测值的最大相对误差为15．8％;分析了任京线管壁蜡沉积物的基本物性和结构强度。研究成果为任京线安全清管提供了理论依据。     

油井结蜡点位置预测及结蜡规律讨论

油井热洗是油井清防蜡的有效措施之一,油井的结蜡规律和井筒结蜡点是油井热洗过程中工艺参数优化设计的重要依据,然而,不同油藏埋藏深度、产液量、含水率的采油井,均具有不同的结蜡规律及井筒结蜡点。因此,若要取得较好的清蜡效果,必须明确油井结蜡点的位置及其结蜡规律。本文根据能量守恒定律及传热学原理,分别建立了油井正常生产过程中温度场分布的数学模型,结合原油析蜡温度,对油井结蜡点位置进行了预判,并对其分布规律进行了分析讨论,进而为油井洗井工艺参数优化提供一定的理论依据。     

华北某区块井筒结蜡原因分析及结蜡程度预测

针对华北某区块油井井筒下部尾管及泵口处结蜡严重的现象,采用多种材料表征手段对结蜡原油和蜡沉积物进行分析,探究该区块井筒的结蜡原因,选取单井日产液量、原油黏度、原油含水量等因素作为影响蜡沉积的自变量,结蜡程度作为因变量,采用布谷鸟算法（CS）优化支持向量机（SVM）对数据进行回归,预测不同油井的结蜡程度。结果表明,该区块原油为高含蜡原油,且原油中重组分较多,沥青质和机械杂质高于其余区块,可作为析蜡中心加速蜡晶析出;从井口到井底,蜡沉积物的相关物性呈纵向分布特征,蜡沉积物中的长直链烷烃越多,平均分子量越大,熔蜡点越高,导致清防蜡困难;通过结蜡程度预测,CS-SVM模型可准确预测结蜡程度,平均相对误差小于5%。研究结果可为类似区块油井清防蜡措施的制定提供实际参考。     

大庆原油蜡沉积规律研究

在理论分析及室内试验的基础上,系统研究了油温、流速、管壁处温度梯度等参数对大庆原油蜡沉积的影响.在原油与管壁温差相同时,不同温度段蜡沉积速率并不相同,存在蜡沉积高峰区.在壁温相同时,随油温升高,蜡沉积速率逐渐增加.在油温、壁温相同的条件下,随流速增加,蜡沉积速率下降.建立了大庆原油蜡沉积模型,并利用该模型预测了铁岭-秦皇岛输油管线不同季节、不同时间沿线蜡沉积分布.铁-秦线冬季存在蜡沉积高峰区;春、秋季出站时蜡沉积最严重,下一站进站时蜡沉积最轻;夏季蜡沉积速率更小,且沿线变化不大.     

某油田区块油井井筒结蜡机理及蜡沉积规律研究

针对某油田区块井筒底部结蜡严重的问题,以原油和沉积物为研究对象,采用流变性测试、族组分分析、红外光谱分析、溶蜡点测试、动力学模型预测等手段,研究了该区块油井的蜡沉积规律与机理.结果表明,该区块油井原油中高碳分子、重质组分含量较高;井筒沉积物以长链直链烷烃为主,异构烷烃较少;原油中机械杂质含量较高,为蜡晶分子的析出提供了...     

大庆原油管输结蜡规律与清管周期的确定

在确定不同流态区管壁处剪切应力、蜡晶溶解度系数、径向温度梯度及管道沿线温降分布的基础上,回归建立了适用于描述大庆油田某两联合站间输油管道蜡沉积的结蜡模型。根据差压法原理,建立了研究原油管输结蜡过程室内模拟试验装置,并覆盖该输油管道的典型工况条件开展了管输原油结蜡模拟试验。相对偏差分析表明,结蜡模型预测结果与试验值的适配性良好。进而在预测运行时间对该输油管道结蜡影响的基础上,结合结蜡层厚度对管道轴向温降及压降的作用,确定了年季节最高与最低土壤温度期的清管作业周期分别为4个月和3个月。     

原油性质对油井结蜡程度的影响

主要就原油的性质对结蜡程度的影响,以及采油井的结蜡规律进行了研究。通过实验得出结论如下:对于不同的油井,原油的含蜡量越高,在相同油井深度处结蜡蜡样的含蜡量也越高,油井结蜡越严重;对于同一口油井,随着油井深度的增加,结蜡蜡样的蜡含量、蜡样相对密度和凝点也相应增加;油井深部结蜡严重,越靠近井口结蜡越轻。     

基于原油及蜡样实验的油井井筒结蜡规律综合分析

高含蜡原油生产时,油井井筒结蜡的影响因素很多也很复杂,仅通过对油样结蜡实验分析或者井筒结蜡厚度的理论分析进行结蜡规律研究比较片面,现场井筒蜡样实验分析及不同气油比压力下结蜡规律实验是必要的补充。以安塞油田高平2井区长10油层原油及蜡样为研究对象,通过黏温曲线测定析蜡温度、原油全组分实验分析、蜡样全组分实验分析、不同气油比和压力条件下实验分析、不同产液量和含水率的理论计算分析等多种手段,全面综合地研究和认识其结蜡规律,为制定清防蜡措施提供了更详实的依据。     

原油生产与输送中的结蜡问题（综述）

原油生产与输送中石蜡结晶和沉积问题使石油工业造成巨大的经济损失。本文主要是全面系统地描述论述与此问题有关的研究情况。对该问题从基础理论方面加以阐述，并进一步讨论石蜡烃的特性以及溶解性能。正构石蜡烃是造成结蜡的主要固定已有定论。这里，对石蜡结晶机理进行了全面论述。正构石蜡烃以外的化合物，尤其是质和树脂对正构石蜡烃的溶解度有很大影响。在评价原油的蜡含量时，所在地区的气候因素应考虑进去。在大多数适宜条件     

油井结蜡相关因素分析和清防蜡对策

针对江苏油田近年来开发的陈堡油田原油含蜡较高、油井容易蜡卡的现状，分析油井蜡卡原因，提出油井结蜡与原油物性、温度、含水、系统压力、地面设施、热洗加药、管杆工况、作业监督的关系和处理方法，并制定了一套行之有效的清防蜡措施。5年来平均延长检泵周期350d，共计增油6800t，取得了显著的经济效益。     

Transportation technology with pour point depressant and wax deposition in a crude oil pipeline

The authors systematically studied transportation technology with pour point depressant and wax deposition in an industrial crude oil pipeline. Experiment results manifest that beneficiated oil acquires obvious modification effect and the reheating temperature of intermediate heat stations should be above 55°C to avoid effect deterioration. Heating schemes are made with lower heating temperature and wider output range. Moreover, an applicable wax deposition model is established to predict wax deposition distribution along the pipeline under various operating conditions. Wax deposition rate varies severely along the pipeline and it is necessary to consider its non-uniformity in production.     

Experimental study on the regulation of wax deposition

Abstract

Based on the theory of wax deposition dynamics, and the wax deposition rate model of a Tieling–Jinxi insulated crude oil pipeline was established for Daqing–Jilin mixed oil. Based on their physical properties, the sediments removed from the pipeline were mixed into the original oil sample at different proportions. The sediment volume measured by three physical methods in different seasons was compared. The results showed that the error between the value measured by the wax content method and the predicted value by the model was the smallest, which was -5% in winter and -3.9% in summer. Therefore, the wax content method can be used to estimate the sediment in the pipeline and determine the prediction accuracy of the model.     

Study of wax deposition law by cold finger device

Wax deposits in oil pipelines can reduce the effective inner diameter of such pipelines, which may lead to pipeline blockage accidents. In this study, a cold finger experimental device was constructed, and eight groups of experimental scenarios under cold flow conditions were performed in accordance with field conditions. The effects of deposition time and cold and hot bath temperatures on wax deposition were investigated. Results show that when the cold bath temperature remains unchanged, and only the hot bath temperature increases, the deposition quality and rate of mixed waxy crude oil will initially decrease and then increase. During this period, the temperature that corresponds to the maximum deposition mass is the starting point of the wax precipitation peak.     

含蜡原油石蜡沉积模拟方法研究

对从苏丹Unity油田现场取得有代表性的原油样品进行了原油组分分析和析蜡点测试。并针对油田的生产状况,利用与美国德士古石油公司合作建立的自动化高压石蜡沉积循环管道模拟系统,采用冷却实验步骤测试了苏丹原油从高于原油析蜡点温度到较低环境温度范围内在现场流速、油温和环境温度下的石蜡沉积速率,定量研究了流速和油温对石蜡沉积速率的影响,并采用分子扩散和剪切效应的总效应来描述石蜡沉积机理。利用临界蜡张力作为模拟放大因子,采用半经验的石蜡沉积数学模型,预测了Unity油田21井的生产井筒在现场生产条件下的石蜡沉积情况,模拟了不同产量和不同时间的蜡沉积剖面。结果表明,该油井在目前高产条件下,未发生石蜡沉积问题;在低产时,须考虑清蜡和防蜡措施。     

高凝原油管道输送蜡沉积规律实验研究

针对高凝原油在管道输送过程中管壁结蜡等问题，通过室内建立的小型管流结蜡环道实验装置，模拟输油管道运行中某一管段的蜡沉积情况，研究了含蜡原油的蜡沉积速度，考察了蜡的沉积规律受温度的影响。通过计算，确定了实验条件下的结蜡量，并利用差热扫描量热仪从微观角度分析测试了蜡沉积物的特性，进而探讨了结蜡机理和影响管壁结蜡的因素。     

Effect of drag reducer and pour point depressant on the wax deposition of crude oil pipeline

In this paper, the data of wax precipitation before and after the addition of the additives showed that the addition of the drag reducing agent (DRA) and the pour point depressant (PPD) cannot change the wax appearance temperature (WAT) of crude oil. When the dosage of DRA is small, the DRA cannot increase, stop, or slow down the precipitation of wax crystals. The addition of PPDs has no influence on the amount of precipitated wax crystals. From the GPC analysis, the molecular weight of the wax deposit samples in Linpu pipeline is from 500 to 76,800, which indicates that there is no enrichment of DRA in wax deposit samples. The results of IR show that the C?O group was not detected in the wax deposit sample of the Wei Jing pipeline, which indicates that there is no enrichment of the PPDs in wax deposit samples. The results showed that the DRA and PPD have no obvious effect on crude oil pipeline wax deposition.