Investigation of factors affecting on viscosity reduction of sludge from Iranian crude oil storage tanks

Crude oil is a kind of water/oil emulsion, which the oil phase consists of organic molecules with different molecular weights such as alkanes, paraffin, asphaltene, and resins. Due to the change in physicochemical conditions during the production, transportation, storage, and refining, heavier molecules can precipitate from crude oil. Thus, viscous sludge formed at the bottom of storage tanks can cause many problems including reduction of storage capacity of tank, oil contamination, corrosion, repair costs, environmental pollution, etc. The reduction of sludge viscosity can be achieved by reduction of its interfacial tension. In this study, different chemical and physical factors, influencing prepared emulsions（made of sludge, water and surfactant）, such as surfactants, solvents, temperature, pressure, and mixing conditions were investigated. Results showed that non-ionic surfactants（like bitumen emulsifier）, and solvents（such as mixed xylene, AW-400, and AW-402）, injection of additives, applying pressure, and mixing operations had a positive effect on reduction of emulsion viscosity. All experiments were carried out with sludge obtained from crude oil storage tanks at Kharg Island,Iran.

The Features of Acoustic Bathymetry of Sludge in Oil Storage Tanks

The features of acoustic bathymetry of sludge in crude oil tanks are considered. Different parameters of crude oil and sludge which are important for the selection of acoustic parameters such as sound speed, the acoustic impedances of “oil-sludge” boundaries and sound attenuation are analyzed and compared with experimental data. The main sources of errors of sludge volume estimation are discussed.

The Computer Aided Integrated Design and Analysis of Oil Tank in Vehicle

This paper creates 3D solid model and assembly of U RJ 92-6 oil tank and analyses its strength by integrated CAD/CAE/CAM software I-D EAS. Through integrated simulation in computer, design efficiency and quality of oil tank is greatly improved. Adopting integrated CAD/CAE/CAM software to carry out integrated research to equ ipment and products, we will be able to take overall analysis in aspects of 3-D solid modeling, pre-assembly and strength, etc., to realize non-paper designi ng and parallel designing. Problems can be found and settled during designing, w hich will increase designing efficiency and one-time success rate and realize o ptimum designing for products.

Sludge Pollution Control from Crude Oil Tank Cleaning

This study investigated the use of microbial analysis as a bioremediation option for remediating petroleum sludge, which is part of the waste stream generated in the petroleum industry. The aim is to reduce environmental burden caused by the discharge of untreated sludge. Sludge sample was cultured in other to isolate microorganisms for the sludge treatment. The selected strain of the organisms after screening were Aspergillus flavus, Aspergillus niger, Verticillus sp, Penicillum sp, and Microsporium audouinii. Bioreactors (labeled A, B, C, D and O) were designed for the treatment of petroleum sludge. These reactors contain 2.0 × 10-2 m3 of the diluted sludge samples and the isolated organisms for the treatment process. On a weekly basis, the control reactors received 1.5 × 10-3 m3 of fresh and saline water respectively. After 12 weeks of treatment, sludge physicochemical characteristics showed distinct variations. From the result, reactor D was the best in terms of remediating the sludge as compared to other reactors. Friedman non-parametric test was performed to check if the weeks of treatment affected the reduction of the total hydrocarbon content (THC) in the five reactors and also checked for significant differences in the THC after treatments. The drop in the THC of the treated sludge ranged from 56.0% to 67.3%. These results showed the possibility of enhanced biodegradation of petroleum sludge by hydrocarbon utilizing microorganisms (fungi).

Impact of Crude Oil Storage Tank Emissions and Gas Flaring on Air/Rainwater Quality and Weather Conditions in Bonny Industrial Island, Nigeria

This study investigated the effects of gaseous emissions from crude storage tank and gas flaring on air and rainwater quality in Bonny Industrial Island. Ambient air quality parameters, rainwater and weather parameters were collected at 60 m, 80 m, 100 m, 200 m and control plot for 4 weeks at the Bonny. Rainwater parameters were investigated using standard laboratory tests. Data analyses were done using Analysis of variance, pairwise t-test and Pearson’s correlation statistical tools. Results show that emission rates, volatile organic compound (VOC) noise and flare temperature decreased with increasing distance from flare points and crude oil storage tanks. Findings further revealed the emission rates varied significantly with distance away from the gas flaring point (F = 6.196;p = 0.004). The mean concentration of pollutants between gas flare site and crude oil storage tank showed that CO (0.02 ± 0.001 - 0.002 ±0.001), SPM (0.011 ± 0.001 - 0.01 ± 0.001), VOC (0.005 ± 0.001 - 0.01 ± 0.001) and NO2 (0.04 ± 0.001 - 0.005 ± 0.000) had significant variations (p > 0.05) with CO, O3 and NO2 having higher concentrations at the gas flare site while SPM, and VOC were higher around the crude oil storage tank site. Wind turbulence was higher around the gas flaring point (4.93 TKE) than the crude oil storage tank (4.55 TKE). Similarly, there was significant variation in the sun radiation, precipitation, and wind speed caused by gas flaring (1582.25 w/m2, 436.25 mm, 0.53 m/s) and crude oil storage tank (1536.25 w/m2, 3.91.41 mm, 0.51 m/s). There were also significant variations in flared temperature (F = 22.144;p = 0.001);NO2 (F = 8.250;p = 0.001), CO (F = 6.000;p = 0.004) and VOC (F = 5.574;p = 0.006) with distance from the gas flaring point. The variation in the rainwater parameters with distance from the gas flaring indicated significant variations in pH (F = 5.594;p = 0.006). The study showed that the concentration of VOC and particulates were high in the supposedly control area which is perceived to be safe for human habitation. Significant variations exist in emission rate (p = 0.015), flare temperature (p = 0.001), NO2 (p = 0.003), VOC (p = 0.001), noise (p = 0.041), hydrogen carbonate (p = 0.037) and chromium (p = 0.032) between the gas flaring and crude oil storage tank. Regular monitoring is advocated to mitigate the harmful effects of the pollutants.

DYNAMIC MODEL FOR OIL SLICK DISPERSION INTO A WATER COLUMN- A WINDDRIVEN WAVETANK EXPERIMENT

A dynamic experiment for oil dispersion into a water column was performed with a 21 m long, 0.5 m wide, and 1 m high wind-driven wave tank. At wind velocity between 6-12 m/s and with the oil slide kept constant (about 1 um), the rate of the oil content increase in the water column could be approximated from the difference between the dispersion rate (R) of the oil slick and the coagulation rate (R’) of the dispersed oil slick. Assuming the coagulation rate is directly proportional to the concentration of the water dispersed oil slick (i. e. R’ =KC),, the integral form of the dynamic model can be expressed as C=R*[1-exp(-K*t)]/K and parameters R and K can be regressed with a computer. The relative deviation of model results from the experimental data was mainly less than 10%. The oil slick dispersion rate (R) had exponential relationship with the wind velocity (V), and can be fitted with a formula R=A*(U+1)B.The fitted constant of the coagulation rate, K(0.8-3.0* 10-3 min-1) did not have significant

Analysis of Thermal Transfer of Reinforced Concrete Submarine Oil Tanks

-The temperature distributions obtained by different methods of analysis for solving thermal transfer of reinforced concrete (R. C.) submarine oil tanks (RCSOT), including flat wall method, cylinder wall method and finite element method, are compared with the experimental data of thermal transfer of RCSOT. The precision and scope of applicability of different methods are discussed. The principle for selecting analysis method for solving thermal transfer of RCSOT is given. The analytical and experimental temperature distributions show that the wall of RCSOT should consist of double walls and empty space between them should be filled with sand or other heat insulation materials to reduce the temperature difference of the wall and to prevent concrete from cracking.

A method for coastal oil tank detection in polarimetric SAR images based on recognition of T-shaped harbor

To automatically detect oil tanks in polarimetric synthetic aperture radar（SAR） images, a coastal oil tank detection method is proposed based on recognition of T-shaped harbor. First of all, the T-shaped harbor is detected to locate the region of interest（ROI） of oil tanks. Then all suspicious targets in the ROI are extracted by the segmentation of strong scattering targets and the classifier of H/α. The template targets are selected from the suspicious targets by the combination of a proposed circular degree parameter and the similarity parameter（SP） of the polarimetric coherency matrix. Finally, oil tanks are detected according to the statistics of the similarity parameter between each suspicious target and template targets in ROI. Polarimetric SAR data acquired by RADARSAT-2 over Berkeley and Singapore areas are used for testing. Experiment results show that most of the targets are correctly detected and the overall detection rate is close to 80%.The false rate is effectively reduced by the proposed algorithm compared with the method without T-shaped harbor recognition.

Optimization Model of Oil-Volume Marking with Tilted Oil Tank

In this paper, the relationship model between the oil volume and the vertically tilting parameter (α), the horizontally tilting parameter (β) and the displayed height of oil (h*) is first constructed with the tilted oil tank. Then, based on the data of the oil output volume at different time of day, an optimization model of oil-volume marking with tilted oil tank is established. Finally, parameters α = 2.2° and β = 3.05° are estimated by using nonlinear least squares method and the marking number of the tank-volume meter is given.

Multiplexing Technique Applied in the Optically Powered Oil-tank Detection System

The method of using multiplexing technique to realize the optically powered multiple detection system is presented. As this system adopted novel time and pulse width multiplexing techniques, reliable separation and error code correcting techniques, it realizes optically powered multiple channel and parameters detection, and successfully applied in the oil tanks for temperature, pressure, liquid level and reserve measurings.

The Research Application of 3D Laser Scanning Technology in the Deformation Detection of Large Cylindrical Oil Tank

In order to ensure the safety in using a large cylindrical storage tank,it is necessary to regularly detect its defonnatioii.The traditional total station method has high accuracy in determining the deformation,however,it has a low measxirement efficiency.Long-term observation means,there are more risks in the petrochemical plant,therefore,this paper proposes the usage of the 3D laser scanner,replacing the traditional total station to determine the defbnnation of a large cylindrical storage tank.The Matlab program,is compiled to calculate the point cloud data,while the tank deformation is analyzed from two different points which are,the local concave convex degree and the ovality degree.It is concluded that,the difference between the data obtained by 3D laser scanning,and total station is within the range of oil tank deformation limit,therefore,3D laser scanner can be used for oil tank deformation detection.

动态热条件下原油罐储维温过程主要影响因素分析

掌握原油罐储维温过程主要影响因素,对原油库实现节能降耗目的起重要作用。在建立动态热条件下含蜡原油罐储维温过程三维理论模型的基础上,提出了加热盘管空间结构、周向效应对罐内对流传热的影响,划分了内、外因素影响区以及过渡区域;采用多元非线性回归的方法,建立不同季节边界位置主控影响因素模型,定量表征了罐边界油温与内、外因素之间的作用机制。结果表明:罐内大涡结构受无加热盘管区域局部湍涡影响,导致大涡结构向无盘管区域发生偏移。罐底低温区域受盘管周向效应影响较大,罐顶边界油品受内外因素影响大,形成最大厚度1.79 m的外界环境影响区;罐壁受保温层影响,只形成了内部维温热流影响区;冬季罐底形成了0.13 m的外界土壤影响区。

形状匹配的铁路油罐车罐口视觉定位方法

为了克服非均匀光照、车型以及摄像机安装位置等因素造成的罐口定位误差,提出了一种基于形状匹配的铁路油罐车罐口视觉定位方法。利用罐口为标准几何形状的特点,使用标准图像提取罐口边缘并进行形状拟合;将得到的轮廓形状作为图像识别模板,在待搜索图像中使用基于轮廓的归一化互相关查找目标;在搜索过程中对形状模板进行缩放,以兼容不同型号车型罐口;利用图像金字塔技术减小计算量,加快匹配速度。结果表明,所提出的方法满足误差要求,能够应用于工业现场。

防止多仓汽车油罐车装错油的技术研究与应用

针对多仓汽车油罐车装油,司机接错进仓油管而装错油事故时有发生,从而导致加油站质量事故,影响企业信誉的问题。借助中石化首座智能油库科研项目的资金,开发了防止汽车油罐车装错油的技术设备。比较详细地介绍了该设备的组成、安装位置与要求、工作原理、改造原发油系统的两种方案及开票系统的修改内容及五个方面的验收要求,经改进完善,先后在笔者所在公司15座油库安装运行,效果良好,值得借鉴推广。

复配絮凝处理高浓度含盐原油罐切水的研究

采用不同类型絮凝剂聚合[聚合氯化铝(PAC)、聚合硫酸铁(PFS)和聚丙烯酰胺(PAM)]处理高浓度含盐原油罐切水,探索絮凝剂投量浓度、搅拌速度、p H值和投加时间间隔对絮凝效果的影响。结果表明:复配使用絮凝剂聚合氯化铝与阳离子型聚丙烯酰胺(CPAM)处理高浓度含盐原油罐切水的絮凝效果更佳。絮凝剂的投量浓度、絮凝搅拌速度、p H值和投加间隔时间均影响絮凝的效果,其中絮凝剂的用量影响最大。较为适宜的絮凝条件:p H值为6~11,PAC投量浓度为400 mg/L且混合搅拌速度为200 r/min,CPAM投量浓度为1.0 mg/L且混合搅拌速度为100 r/min,2种絮凝剂的投加间隔为60 min。絮凝对浊度的去除率高达98.7%,固体悬浮物(SS)的去除率高达96.5%,废水中的石油类含量从0.339 mg/L降到0.115 mg/L,废水的氨氮、化学需氧量(COD)以及254 nm波长紫外光下的吸光度(UV_(254))的去除率分别达到55.0%,36.6%和20.4%,最终絮凝出水的总铁含量从41.85 mg/L降到5.42 mg/L。

防回油冲击液压油箱结构改进

液压系统有向集成化、轻量化发展的趋势。液压油箱小型化,会导致油液回油时产生回油冲击,造成油箱内部发生卷气现象,使油液中气体污染物含量增高,影响油液品质,甚至在油箱透气帽处发生油液飞溅现象,影响系统密封性。针对油箱的使用工况,分析仿真模型的适用条件,建立AGV小车油箱的有限元仿真模型,分析初始情况和结构改进后油箱内部的油液运动状态。对AGV小车进行验证性实验,对比数值模拟结果,回油液面状态相近,仿真模型计算效果良好,基于仿真模型得到能够减轻该油箱回油冲击的油箱结构改进方法。

加油站地下油罐清洗存在的问题与对策

在简要介绍了目前加油站地下常用油罐的特点和油罐清洗的基本要求、作业方式和流程的前提下,针对当前加油站地下双层油罐清洗存在的清洗安全性与质量、清洗与危废处理、清洗安全与油气排放监管、油罐清洗标准规范不清晰、管理职责不明确以及清洗安全风险防范不足的问题,提出了相应对策:一是作好清罐工作的建章立制;二是选用适宜的清罐方式;三是加强清罐作业的安全风险识别与防护。

液压油箱回油流场气泡析出的数值仿真与实验验证

液压油箱回油管有置于液面之上和液面之下两种方式,易造成不同程度的气泡析出,从而影响飞机液压系统的性能和可靠性。为此,利用k-ω SST两方程模型针对两种方式进行回油流场气泡析出的数值模拟,仿真研究气泡在油液油箱内的流动与分布规律。结果表明,前者随液面高度的增加气泡越集中聚集,其气体体积分数就越大,且油液上表面的气体体积分数最大可达12.35%,而油箱底部气泡含量最低仅为0.512%;后者气泡聚集分布规律与前者相似,油液上表面的气泡体积分数最大为9.57%,油箱底部气泡含量最低仅为0.056%,相较前者最高和最低体积分数都减少了,且油箱吸油口截面处的气泡体积分数显著减少。最后,实验验证了仿真的正确性,可为油箱新构型的设计提供参考。

大型原油储罐腐蚀原因分析及防护对策研究

通过调查大型原油储罐底板沉积水腐蚀物成分、土壤电阻率等,分析储罐腐蚀原因,提出涂料防腐、阴极保护联合防护对策,采用一种新型阴极保护方法,并对防腐效果进行检验。结果表明,采用新型智能同步恒断电位仪防腐措施的储罐阴极保护效果显著,有效降低了储罐底板腐蚀速率,减少了维护成本。

大型石油储罐主动安全防护技术的应用探析

大型石油储罐浮顶密闭空间属于密封环形油气积聚空间,收发油作业时浮盘升降会积聚大量挥发可燃气体,当浓度超出爆炸极限时,遇到静电、雷击产生的火花就极易引发燃烧或爆炸事故。基于此,通过提出一种混合气体实时监测与惰化技术,在储罐浮顶处安装混合气体探测与保护系统,及时注入氮气类惰性气体降低可燃气体浓度,保障安全生产。通过测试应用,该项技术实用效果较好。