高凝油油藏微观剩余油分布影响因素分析——以大民屯凹陷S84-A12块为例

高凝油藏剩余油分布状态决定了油藏的开发调整方式,但前人针对剩余油动态变化影响分析较少。由于油品的特殊性,含蜡量及开采驱替方式均会对储层孔隙结构进行改造从而影响微观剩余油的分布。基于此,利用高精度电子计算机断层扫描(computed tomography,CT)技术建立数字岩心模型,恢复微观孔隙结构,实验分析得出微观剩余油动态变化主要受含蜡量及驱替程度影响。随温度降低蜡滴析出加快,含蜡量增加从而分割孔隙中剩余油。驱替倍数提高,储层孔喉连通性提高,剩余油分布样式由块状、网络状向孤滴状变化。

Analysis of influence factors of micro remaining oil distribution of high pour point oil reservoir

The distribution of remaining oil in high pour point reservoir determines the development adjustment mode of the reservoir, but researches on the factors that influence the dynamic change of remaining oil are absent. Because of the particularity of oil properties, wax content and production displacement methods will modify the pore structure of reservoirs and affect the distribution of micro remaining oil. In this condition, a digital core model is established by using high precision CT scanning technology to restore micro-pore structure. The experimental analysis shows that the dynamic change of micro-residual oil is mainly affected by wax content and displacement degree. With the decrease of temperature, the precipitation of wax droplets speeds up the increase of wax content and divides the remaining oil in the pore. With the increase of displacement multiple, the connectivity of reservoir pore roar is improved and the distribution pattern of remaining oil varies from block, network to solitary drop.