【作者】 陶磊；

【导师】 李兆敏；

【作者基本信息】 中国石油大学 ， 油气田开发工程， 2009， 博士

【摘要】 目前胜利油田原油粘度超过10×10⁴mPa·s的超稠油储量5159×10⁴t,占未动用稠油储量的38%,是胜利油田主要的未动用资源之一,粘度大、埋藏深、储层薄的特点是导致这类油藏难以动用的主要原因。胜利油田通过开展油溶性降粘剂、CO₂、蒸汽三元复合吞吐技术在深薄层超稠油开采方面取得了一定的突破。深入研究三元复合吞吐单体及协同作用对超稠油物理化学性质的作用机理,完善三元复合吞吐技术,对更加高效的开发深薄层超稠油油藏具有重要意义。论文从研究胜利油田超稠油性质出发,实验测量了超稠油的密度、粘度、沥青质分子形态,四组分含量及分子量。根据胜利油田超稠油特性研制了超稠油油溶性复合降粘剂。针对降粘率在描述超稠油降粘效果方面的不足提出了新的评价参数-降粘倍率。室内实验表明超稠油油溶性复合降粘剂在低含水和中高含水条件下均能实现降粘,降粘效果随温度和含水升高而增强。推导了CO₂立方型状态方程,与PR和RSK状态方程相比,该方程计算结果稳定,精确度高。通过PVT仪和落球粘度计进行了CO₂对超稠油的溶胀、降粘实验。研究结果表明CO₂能够溶解于超稠油且使其体积膨胀,油包水乳状液含水越高溶解CO₂的能力越弱,溶解CO₂后膨胀能力越差,超稠油溶解CO₂后粘度急剧降低,且原油含水越高CO₂降粘效果越好。降粘剂、CO₂、加热三个元素两两之间的协同作用改善超稠油流变性能实验表明协同效果优于各个元素单独作用的效果。通过高温高压釜反应和回采油样分析研究了三元复合吞吐技术对超稠油化学性质的影响,实验结果表明三元复合吞吐技术能够实现超稠油大分子的解聚,使超稠油饱和分、芳香分含量增加和胶质、沥青质含量减小,使超稠油沥青质分子量明显减小。根据胜利油田郑411超稠油油藏地质特征、多组分流体相态拟合生成的流体组分数据,结合超稠油油溶性复合降粘剂解聚和降低界面张力的作用,建立了三元复合吞吐数值模型。研究了高效降粘剂、CO₂、蒸汽对开发效果的影响,并对三元复合吞吐注入参数进行了优化。三元复合吞吐技术在胜利油田得到成功运用,文中阐述了该技术的应用效果和应用前景。更多还原

【Abstract】 About 5159×10⁴t reserve of ultra-heavy oil with viscosity larger than 10×10⁴ mPa·s hasn’t been developed because of large viscosity, deep and thin layer, which shares 38% of undeveloped heavy oil reserve and is one of the major undeveloped resources, since the ternary combination huff and puff technique composed of oil-soluble viscosity reducer, CO₂, steam is invented and applied successfully in Shengli Oilfield. Research on the mechanism of separate or cooperative effect of oil-soluble, CO₂ and steam to ultra-heavy oil and improving the ternary combination huff and puff technique is quite necessary for developed this kind of reservoir efficiently.The density, viscosity, asphaltene structure, four fractions mass fraction and molecular weight of ultra-heavy oil were systematically researched by laboratory experiment. Oil-soluble combined viscosity reducer for ultra-heavy oil was developed based on the properties of ultra-heavy oil, which is powerful for decreasing viscosity under the conditions of low water cut, high water cut and high temperature. As rate of viscosity reduction has the shortage on describing viscosity reduction ability for ultra-heavy oil, multiplying factor of viscosity reduction was employed. A new equation of state for CO₂ is conducted which is better than PR and RSK equation of state on predicting CO₂ state. CO₂ solubility in ultra- heavy oil or emulsion with different water cut, swelling factor, density, viscosity of ultra-heavy oil dissolved CO₂ was systematically researched by laboratory experiments. The results show that CO₂ can dissolve in, swell ultra-heavy oil and considerably reduce the viscosity of ultra-heavy oil. Water cut has negative effects for CO₂ dissolving in and swelling ultra- heavy oil emulsion, but has positive effects on reducing viscosity. The experiment results show that the cooperation of two of Viscosity reducer, CO₂ and heating is more efficient on improving rheological properties of ultra-heavy oil than single. The ternary combination huff and puff technique has ability on disaggregation of big molecule in ultra-heavy oil, decreasing the rate and the molecular weight of resin and asphaltene, increasing the rate of saturate and aromatic. The simulation model of ternary combination huff and puff was created according the basic geological data, property data of compositions, disaggregation data and IFT reduction data of viscosity reducer. The effect on improving recovery of ultra-heavy oil reservoir and injected parameters of viscosity reducer, CO₂ and steam were studied by the simulation model of ternary combination huff and puff. The ternary combination huff and puff technique was evaluated by production data of ultra-heavy oil reservoirs in Shengli Oilfield which have successfully applied this technique.更多还原