稠油热采条件下沥青质沉积热模拟实验研究及影响因素分析——以辽河油田曙一区杜84块兴隆台油层稠油油藏为例

该文以辽河油田曙一区杜84块兴隆台油层超稠油油藏为例,进行了12次热模拟实验.结果分析表明,引起地层伤害最本质的因素是沥青质沉积.沥青质在孔隙中的沉积现象非常普遍,主要呈星点状、薄膜状、斑块状甚至网状等.沥青质沉积对孔渗的伤害程度随温度的增高呈增大的趋势,而随压力增大的变化在小于11. MPa时呈增大的趋势,在大于11. MPa时则呈减小的趋势.其对孔隙度的伤害程度不及对渗透率的那么明显,后者的伤害率平均在80%以上,属强度伤害,而前者的伤害率只有1.3%～6.5%.影响沥青质沉积的因素主要是稠油的组成、温度、压力以及溶剂等. 

THERMAL SIMULATION TESTING STUDY AND INFLUENCE FACTOR ANALYSIS OF ASPHALTENE PRECIPITATION IN THE CONDITION OF VISCOUS OIL THERMAL RECOVERY-a case study of viscous oil pools in the Xinglongtai oil reservoirs of Du-84 block, Shuguang-1 district, Liaohe oil

Twelve times of the thermal simulation experiment were done with samples from viscous oil pools in the Xinglongtai oil reservoirs of Du 84 block, Shuguang 1 district, Liaohe oilfield. The results of the experiment indicated that the essential factor resulting in formation damage was asphaltene precipitation. The phenomenon that asphaltene precipitated in pores was very prevalent. The aggregated asphaltene took the shapes of star spots, films, patches or even networks. The damage degree of asphaltene precipitation to porosity and permeability increased with temperature . It increased with pressure when the pressure was less than 11.5MPa, but decreased with pressure when the pressure was more than 11.5MPa. The average damage rate of permeability was above 80%. It belonged to strong damage. The damage rate of porosity was only 1.3%-6.5%. The major affecting factors of asphaltene precipitation were the component of viscous oil, temperature, pressure and solvent.