致密油藏CO_(2)驱沥青质沉积评价方法研究进展

Research Progress on Evaluation Methods of Asphaltene Deposition in CO_(2) Flooding in Tight Reservoirs

随着我国致密油气资源的不断开发,注气开采已经成为各油田主要的开发方式,而油藏压力、地层温度、原油组分以及储层性质的不断改变,原油胶体体系容易失去平衡,原油中的沥青质分子不断絮凝沉积,堆积在储层岩石的孔隙中堵塞孔喉,导致致密油气开采困难。从评价沥青质沉积量的角度出发,综述CO_(2)驱过程中沥青质沉积的评价方法:驱替实验法、微观可视化实验法、滴定扩散法、在线过滤法、光学法、黏度法及电导率法,对比分析现有评价方法的优缺点,阐述沥青质沉积评价方法的发展趋势。

With the continuous development of tight oil and gas resources in China,gas injection has become the main development mode of each oil field.However,due to constant changes in reservoir pressure,formation temperature,crude oil composition and reservoir properties,the colloid system of crude oil is easy to lose balance.The asphaltene molecules in crude oil are continuously flocculated and deposited in the pores of reservoir rocks,blocking the pores and throats,resulting the difficulty of tight oil and gas exploitation.From the point of view of evaluating the amount of asphaltene deposition,the evaluation methods of asphaltene deposition in CO_(2) flooding are reviewed,including displacement experiment method,microscopic visualization experiment method,titration diffusion method,on-line filtration method,optical method,viscosity method and conductivity method.The advantages and disadvantages of existing evaluation methods are compared and analyzed,and the development trend of asphaltene deposition evaluation methods is expounded.