【作者】 赵军；

【导师】 韩洪升； 马英利；

【作者基本信息】 大庆石油学院 ， 石油与天然气工程， 2008， 硕士

【摘要】 我国原油80%以上为含蜡原油,其流变性及管输工艺一直是我国油气储运界科学研究的主题之一。常温下含蜡原油流动性较差,传统上主要采用加热输送工艺,但是该工艺存在输量范围较窄、输送能耗大、设备投资和管理费用高以及管道运行安全隐患等问题。加剂处理可以改变原油中固态烃的结晶形态,使其不易形成空间网络结构,达到降凝、降粘,改善原油低温流变性的目的,从而实现降低管输能耗、提高安全性的目的。但是,在长距离管输过程中,受高速剪切、重复加热等多种因素影响,加剂原油流动性会变差;此外,热油管道存在停输再启动的问题,停输造成的温降使原油在凝点附近析出蜡晶,形成具有一定强度的胶凝状网络结构,而呈现复杂的触变性。因此,为紧密配合我国石油工业“十一五规划”提出的节能降耗发展目标及辽河油田油气勘探开发形势与主攻目标,立题开展“辽河高凝油流变性及加降凝剂管输方案研究”,不仅可以为辽河原油的管输方案设计提供基本的实验参考数据,而且对指导含蜡原油的生产实践具有重要的理论和现实意义。本文基于原油流变学、非牛顿流体力学、石油化学、结晶学、原油管输工艺学等理论,以辽河原油为研究对象,结合原油物性及实验影响因素分析,制定出实验研究的评价指标及实验方案;从连续介质力学宏观分析的角度,利用HAAKE RS600高端旋转流变仪开展了大量的室内实验,并运用微观研究方法,测定了油样的流变曲线和粘温曲线,建立了流变方程和粘温方程;通过对触变性机理和触变性流体特征的研究,首次对辽河原油测定出滞回环曲线、结构破坏与恢复粘时曲线、剪切应力裂降过程曲线,并在理论研究和实验结果的基础之上,建立了能定量描述含蜡原油剪切应力裂降过程的新型三参数触变模式τ=τ_∞e^b/（t+c）,该模型具有精度高、参数少、实验简便且适用性强的特点;通过对含蜡原油流变性的影响因素理论研究,开展了加剂条件优选及BEM-5P降凝剂室内评价实验,进一步揭示了降凝剂对辽河原油作用机理,在此基础之上,提出了辽河原油管输的可行性方案。更多还原

【Abstract】 Over 80% of the crude in China is waxy crude, of which the rheological behaviour and the corresponding pipelinepipeline technology are being the subjects in domestic researches on oil & gas storage and transportation for a long time. Being of poor fluidity at the normal temperature, heating transporting technique is commonly adopted. This technique, however, is of deficiencies in throughput, energy dissipation, facility cost, management expenses as well as safty etc. Adding depressant into the crude can effectively solve these problems, as the wax crystal morphology of soilid hydrocarbon is changed from the priginal spatial network structure to low the pour point and the viscosity and further improve the rheological behaviour at lower temperature. However, with the effects of high-speed shearing and repeated heating during long-distance pipe conveying, the rheological behaviour is redegraded. In addition, since the waxes condensate near the pour point as the temperature dorp caused by the shutdown and a gelling netted texture is formed, the crude is of complex thixotrophy. According to the energy saving and consumption reduction that initiated in the 11th Five-year Plan for Oil Industry as well as the Oil-Gas exploration and development of Huabei Oilfield, the researches in this paper is not only can offer basic datum for the optimization of pipeline transport design, but also of great theoretical and practical significance for waxy crude production.Based on the theories of rheology, Non-Newtonian Fluid Mechanics, petroleum chemistry, crystallography and pipeline technology etc. and sampling Huabei crudes, experimental indexes and programmes are drew out, integrating the oil properties and parameter analysis; in terms of the macro analysis of continuum mechanics, substantial experiments are conducted with HAAKE RS600 rotational rheometer and the rheological equation as well as the viscosity-temperature equation are further developed with tested rhrogramme and viscosity-temperature curve, respectively. Beased on the researches on thixotropic mechanism and thixotropy fluid property, hysteresis loop curve, structure failure and viscosity build-up curve as well as shear stress decrement curve for one type oil are first present in this paper. According to the theoretical researches and testing results, a novel thixotropy equation withτ=τ_∞e^b/（t+c） pattern, which is of hi-accuracy, few parameter and simplicity, is developed. Considering the influence of various parameters on rheological behaviour, depressant adding condition is optimized and experimental evaluation on BEM-5P is conducted, which further unrip its mechanism on the Huabei crude. A corresponding viable pipe transportion programmel is also recommended.更多还原