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。     

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。     

高压含气条件下含蜡原油析蜡点测量方法

针对常规方法只能测量地面脱气油的析蜡点,不能测量高压含气条件(油藏条件)下含蜡原油析蜡点的不足,提出了以Arrhenius方程为理论基础,利用高压毛细管黏度计测量高压含气条件下含蜡原油析蜡点的方法。实验结果表明,实验油样地面脱气后析蜡点为63.74℃,油藏条件下析蜡点为59.73℃,含蜡原油地面脱气后更容易析蜡。建议采用油藏条件下的析蜡点作为注水设计参数。     

Non-isothermal crystallization kinetics of waxy crude oil

The crystallization behavior of Shengli waxy crude oil from the sol state to gel state was studied by the microscopic observation and DSC curve. The study shows that as the cooling rate decreases, the number of wax grains becomes smaller, the area is larger and the morphology of wax crystals is more irregular. Moreover, under different cooling rates, wax crystals were homogeneous transient nucleation, but the growth mode of wax crystals was different. When the cooling rate is between 1–4?°C/min, Crystallization Peak 1 wax crystal grows according to the mixed crystal mode of one-dimensional rod crystal and two-dimensional discoid crystal; When the cooling rate is between 6–8?°C/min, Crystallization Peak 1 wax crystal grows according to the mixed crystal mode of two dimensional discoid crystal and three-dimensional spherical crystal; Crystallization Peak 2 wax crystal grows according to the mixed crystal mode of two dimensional discoid crystal and three-dimensional spherical crystal at different cooling rates. Crystallization activation energy of crystallization Peak 1 and Peak 2 are 556.91?kJ/mol and 299.62?kJ/mol, respectively.     

Microbial treatment of waxy crude oil for mitigating wax precipitation and improving liquidity

The wax deposition of crude oil during transportation reduces the inner diameter, blocks the pipeline, and eventually increases the cost of petroleum production. This study reports a paraffin-degrading bacterial strain DG2 isolated from petroleum-contaminated soil. The effect of this strain on the removal of paraffin in crude oil was investigated. DG2, identified as Pseudomonas, produced biosurfactant that reduced the surface tension to 35.7?mN/m^?1 and exhibited high emulsification activity. Results of gas chromatography–mass spectrometry analysis of the waxy crude oil treated by DG2 showed decreased heavy hydrocarbon fractions (C25 and C32). The degradation test revealed that DG2 reduced the wax appearance temperature by 4.16?°C and the viscosity by 23% of the waxy crude oil. These findings indicate that paraffin-degradation strain DG2 may be used for effective paraffin biodegradation.     

Estimation of wax deposition in the oil production units using RBF-ANN strategy

Accurate prediction of the solid deposition is petroleum industry can result in increasing the production efficiency. This can also result in the elimination of a major industrial problem, namely the wax deposition. In this study, application of intelligent methods in prediction of the wax deposition is investigated by developing a radial basis function artificial neural network. Levenberg Marquardt algorithm is also applied to determine the optimum predictions. Results from the proposed model are also compared to Kamari et al. model revealing the better performance of the proposed RBF-ANN. The validity of the proposed model is also investigated using statistical and graphical approaches, illustrating the great capability of the proposed RBF-ANN in accurate prediction of the wax deposition. R-squared and mean squared error values of 0.9975 and 0.029251 are obtained for the proposed model, revealing the validity of the RBF-ANN in estimating the wax deposition.     

Determination of wax content in crude oil

Wax deposition is one of the chronic problems in the petroleum industry. The various crude oils present in the world contain wax contents of up to 32.5%. Paraffin waxes consist of straight chain saturated hydrocarbons with carbons atoms ranging from C18 to C36. Paraffin wax consists mostly with normal paraffin content (80–90%), while, the rest consists of branched paraffins (iso-paraffins) and cycloparaffins. The sources of higher molecular weight waxes in oils have not yet been proven and are under exploration. Waxes may precipitate as the temperature decreases and a solid phase may arise due to their low solubility. For instance, paraffinic waxes can precipitate out when temperature decreases during oil production, transportation through pipelines, and oil storage. The process of solvent dewaxing is used to remove wax from either distillate or residual feedstocks at any stage in the refining process. The solvents used, methyl-ethyl ketone and toluene, can then be separated from dewaxed oil filtrate stream by membrane process and recycled back to be used again in solvent dewaxing process.     

2.2Mt/a蜡油加氢装置第一周期运行分析

介绍中国石油化工股份有限公司洛阳分公司2.2 Mt/a蜡油加氢装置第一周期运行情况。该装置采用抚顺石油化工研究院研制的新型FF-18(Ni-Mo/γ-Al2O3)催化剂,保护剂为FZC-100,FZC-102B,FZC-103,FZC-204。在装置处理量235～275 t/h下,反应器床层径向温差最大2.1℃,最小0.2℃,说明径向温度分布均匀、温差小、催化剂装填均匀、床层内的沟流效应很小。在反应器入口温度365℃,系统压力10.72 MPa下,催化剂在使用周期末期,反应器入口温度只比初期设计温度高8℃,而负荷率在104%情况下,平均脱硫率在80%以上,精制蜡油平均硫质量分数为0.138%,低于产品指标值(小于0.16%),说明新型催化剂FF-18相对活性仍然较高,稳定性较好。     

差示扫描量热法在原油蜡含量测定中的应用

我国原油含蜡量较高,蜡含量的测定为原油管道优化运行提供相关数据,保障原油管道安全运行。本文简单比较了三种原油蜡含量测定方法,重点对差示扫描量热法进行了详细阐述。利用差示扫描量热仪DSC822e进行比对试验,对差示扫描量热法在原油蜡含量测定中的准确性和重复性进行了验证,证明了差示扫描量热法在实际应用中的可靠性。     

高含蜡原油生产中析蜡和熔蜡规律实验研究

运用激光测试高压原油析蜡点的最新方法,对井筒中原油的析蜡规律和地层中原油的熔蜡规律进行了研究。研究结果表明：含气原油比脱气原油的析蜡点温度低;井筒中压力高于泡点压力时,原油析蜡点随压力下降而下降;压力低于泡点压力时,原油析蜡点随压力下降而升高;地层条件下熔蜡温度比析蜡温度高。     

Prediction the variation range of wax deposition with temperature of crude oil in a flow loop

Wax deposition under different temperature conditions was investigated in a flow loop, using a local crude oil with a wax content of 22.5%. The results revealed that the wax deposition increases with increasing coolant temperature. However, the amount of deposit increased initially with increasing oil temperature and then decreased. Based on these results, the corresponding temperature ranges were divided into three ranges: hot flow, sensitive precipitation of wax crystal, and cold flow. Based on diffusion mass, a method and steps for determining the temperature dependence of wax deposition were proposed.     

Nano-composite pour point depressants in improving the rheology of waxy crude oil

This article mainly describes the advantages of nano-pour point depressants on the low-temperature fluidity of crude oil compared with traditional pour point depressants. The common nano-pour point depressants are mainly divided blend type and polymerization type. It can effectively improve wax crystal structure and strength, thereby improving the low-temperature fluidity of crude oil. Nano-particles have better application prospects in improving rheological properties of waxy crude oil.     

Evaluation of the inhibitor selection on wax deposition for Malaysian crude oil

Wax precipitates from crude oil when a fluid is cooled down below its wax appearance temperature (WAT). This particularly happens during the transportation of crude oil in the pipeline system. In this study, chemical inhibitors were chosen to prevent and reduce wax formation using seven different types of inhibitors, which are poly (ethylene-co-vinyl acetate) (EVA), poly (maleic anhydride-alt-1-octadecene) (MA), diethanolamine (DEA), cocamide diethanolamine (C–DEA), toluene, acetone, and cyclohexane. The total waxes deposited from the cold finger test are subjected to the type of inhibitor, rotation speed of impeller, and inhibitor concentration. EVA is suggested as the most effective inhibitor based on the amount of wax deposit weight and the value of viscosity. Therefore, this result might be useful for further research work related to wax deposition in the area of crude oil production.     

吉林油田高含蜡稠油油藏有效开发方式研究

C 油田为吉林油田新发现的浅层稠油油田,由于埋藏浅而引起油层低温、低压,油层条件下原油 流动性差,开采过程中储层易受析蜡冷伤害,造成常规开采产能低,甚至无产能,严重影响了油田的正常 生产,制约了该区储量的有效动用。针对这一现状,对该油田重点开展了原油析蜡实验、热采物理模拟实 验、热采数值模拟研究,从理论上明确了提高地层温度、保持地层压力、预防原油析蜡是实现C 油田有效 开发的关键。结合现场蒸汽吞吐、蒸汽驱、火烧油层等多种热采试验的开发效果,明确了主体资源可采用 热水驱开发,局部低温、高含蜡区可采用火烧油层的开发方式。     

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.     

RVHT技术在蜡油加氢装置上的工业应用

介绍了RVHT技术在130万t/a蜡油加氢装置上的工业应用情况。结果表明,专用催化剂硫化效果较好,上硫率为98.1%;该工艺操作过程平稳,产品性质优良,在平均反应温度为347.5℃的缓和工艺条件下,原料油脱硫率达到85%;加氢处理后的蜡油作为催化裂化装置进料,可使各产品中的含硫量大幅度降低,其中汽油含硫量由480μg/g降低至66μg/g。     

影响蜡油加氢处理装置氢耗因素的分析

对中国石油化工股份有限公司洛阳分公司蜡油加氢处理装置影响氢耗的因素进行了分析并提出改进建议。结果表明:蜡油加氢处理装置氢耗随原料油密度、原料油硫含量和反应温度升高而增大。原料油密度在891～908 kg/m3时,化学氢耗为5.15～6.95 kg/t;原料油硫质量分数为0.674%～1.097%时,化学氢耗为4.25～6.28 kg/t;反应温度为299～337℃时,化学氢耗为5.31～5.90 kg/t。为了降低氢耗,热高压分离器温度选择在240～260℃,冷高压分离器操作温度控制在45～55℃,以降低循环氢溶解损失。同时,装置应定期进行闭灯检查以防止装置氢气泄漏。在满足生产的条件下,尽量减少排放废氢气。     

YS-3清防蜡剂的研制

盘古梁油田原油含蜡量高（12%-20%）,部分油井严重结蜡致使热洗频繁。为此研发了以有机溶剂、表面活性剂和高分子聚合物（蜡晶改进剂）、渗透剂、加重剂等组成的油溶性YS-3清防蜡剂。测定结果表明：该清防蜡剂溶蜡速率为2.3 mg/mL.min（50℃）,加剂量为100 mg/L时防蜡率为58.8%,使原油凝点降低5℃,黏度降低19.7%。自2003年9月起,在盘古梁油田结蜡严重、热洗频繁的盘58-27和盘59-25两个井组10口井应用YS-3清防蜡剂,现场加剂量100-120 mg/L,油井平均热洗周期由145天延长到一年以上,清防蜡效果明显。表3参2。     

催化剂LV-23 BC在蜡油催化裂化装置上的工业应用

在100万t/a蜡油催化裂化装置上进行了催化剂LV-23 BC的工业应用试验。结果表明,在原料和主要操作条件基本不变的情况下,产品干气收率下降了0.83个百分点,焦炭收率下降了1.24个百分点,汽油收率下降了3.02个百分点,液化气收率提高了0.85个百分点,柴油收率提高了4.24个百分点,液收提高了2.07个百分点;LV-23 BC中铁、镍等金属含量较低,且对产品柴油、干气、液化气等质量无不良影响。