南梁油田含蜡原油蜡沉积影响因素分析  

Analysis on Factors Influencing Wax Deposition of Wax-bearing Crude Oil in Nanliang Oilfield

作　　者：张鑫鑫 吕祥鸿[1] 李佳维[2] 邓菁玉 李宁 刘艳明 ZHANG Xin-xin;LYU Xiang-hong;LI Jia-wei;DENG Jing-yu;LI Ning;LIU Yan-ming(School of Material Science and Engineering,Xi’an Shiyou University,Xi’an Shaanxi 710065,China;No.2 Oil Production Plant,PetroChina Changqing Oilfield Company,Qingyang Gansu 745100,China)

机构地区：[1]西安石油大学材料科学与工程学院,陕西西安710065 [2]中国石油长庆油田分公司第二采油厂,甘肃庆阳745100

出　　处：《当代化工》2023年第10期2345-2351,共7页Contemporary Chemical Industry

基　　金：国家自然科学基金青年科学基金项目,W/B4C纳米多层涂层的界面结构和强韧化机理研究(项目编号:51902254)。

摘　　要：在含蜡原油的开采和集输过程中,蜡沉积可导致油井产量降低、管道输送能力减弱等问题,严重影响油田运营的安全性和经济性,而明确原油蜡沉积特性及影响因素是制定清防蜡措施的关键。以南梁油田为研究对象,利用自制冷指实验和环道实验装置,研究了油壁温差、沉积时间、油管表面状态对原油蜡沉积的影响规律,并结合分子动力学模拟探讨了不同蜡分子与裸钢(α-Fe)、FeCO_(3)腐蚀膜及聚四氟乙烯(PTFE)防蜡涂层之间的作用机理。结果表明:在相同油温(60℃)下,随着油壁温度从20℃升高到40℃,结蜡速率从198.84 g·m^(-2)·h^(-1)降低至5.33g·m^(-2)·h^(-1);随着沉积时间延长,结蜡速率降低;随着油管表面粗糙度增加,蜡沉积速率升高,含FeCO_(3)腐蚀膜表面更易结蜡,而防蜡涂层油管的蜡沉积速率仅为裸油管的一半,防蜡率为52.92%。分子动力学模拟结果表明,蜡分子在油管不同表面的吸附倾向由大到小顺序为:FeCO_(3)、α-Fe、PTFE;有支链或碳数较高的蜡分子更易吸附于油管表面。总之,油管表面粗糙度及其附着物与蜡分子的吸附特性共同决定不同油管表面状态下的蜡沉积特性。In the extraction and gathering process of waxy crude oil,wax deposition can reduce the oil well production and pipeline transportation capacity,which seriously affects the safety and economy of the oilfield operation.It is very important to clarify the wax deposition characteristics and influencing factors for the development of wax removal and control.In this paper,Nanliang waxy crude oil was regarded as the research object,the influence of the difference of oil/wall temperature,deposition time and the surface condition of the tube on wax deposition was studied by using the homemade cold-finger and ring channel experiment.Moreover,the interaction mechanism between wax molecules and bare steel(α-Fe),FeCO_(3)corrosion film and polytetrafluoroethylene(PTFE)anti-wax coating was investigated by molecular dynamics simulation.Under the same oil temperature about 60,the wax deposition℃rate increased from 5.33 g·m^(-2)·h^(-1)to 198.84 g·m^(-2)·h^(-1)as the tube wall temperature decreased from 40℃to 20℃.With the increase of the deposition time,the amount of wax deposition increased,but the wax deposition rate decreased.As the surface roughness of the tube increased,the wax deposition rate increased.The tube covered with the FeCO_(3)corrosion film showed the highest wax deposition rate.The wax deposition rate of the anti-wax coated tubing was only half that of the bare tubing,and the wax prevention rate reached 52.92%.Additionally,the molecular dynamics simulation results showed that the adsorption tendency of wax molecules on different tubing surfaces was FeCO_(3)>α-Fe>PTFE,and wax molecules with branched chains or higher carbon number were more easily adsorbed on the tubing surface.In conclusion,both the surface roughness of tubing and the adsorption characteristics of wax molecules on its attachment determine the wax deposition characteristics under different tubing surface conditions.

关 键 词：含蜡原油 蜡沉积 结蜡影响因素 分子动力学模拟 

分 类 号：TE358.2[石油与天然气工程—油气田开发工程]