考虑沥青质沉积的储层压力场数值模拟  

Numerical Simulation of Reservoir Pressure Considering Asphaltene Deposition

作　　者：崔传智[1] 刘力军 武改红 李荣涛 高丽[2] 

机构地区：[1]中国石油大学(华东)石油工程学院,青岛266580 [2]中国石油辽河油田公司勘探开发研究院,盘锦124010

出　　处：《科学技术与工程》2017年第35期40-45,共6页Science Technology and Engineering

基　　金：国家重大科技专项(2016ZX05011-002)资助

摘　　要：油藏开发过程中,随着储层压力的下降和轻质组分的采出,原油中的胶质、沥青质等重质成分逐渐析出并沉积在岩石孔隙表面,造成渗流通道的堵塞,导致开发效果变差。本文根据相平衡理论和修正的Flory-Huggins溶解理论,建立了沥青质组分的最大溶解度模型,结合毛管束模型,推导了沥青质沉积对孔喉半径的影响公式,建立了单井渗流模型,并对模型进行了求解;与常规模型相比,该模型考虑了沥青质沉积造成的绝对渗透率损伤,压力场的波动导致沥青质的析出,而沥青质的析出又会反作用于压力场,影响开发效果。研究结果表明,随着储层压力降低,沥青质的溶解度先减小后增大,在饱和压力处取得最低值,为减少沥青质析出对开发效果的影响,应尽量使地层压力保持在饱和压力附近;沥青质沉积主要发生在生产井附近,随着到生产井距离的增大,沥青质沉积量逐渐减小,对储层渗透率、孔隙度的影响也逐渐变弱;压力场求解结果表明,当考虑沥青质沉积时,生产井附近渗流阻力增大,地层压力衰减加快。During oilfield development,the reservoir pressure drops continuously and the light component are produced earlier,which induce that the asphaltene in crude oil precipitate and deposit on the rock pore surface.The asphaltene deposition may cause the decrease of reservoir porosity and permeability,then result in the decline of production capacity. In this work,based on the phase equilibrium theory and Flory-Huggins dissolution theory,the dissolution model of asphaltene is built and the seepage model considering the variation of porosity and permeability is established. The calculation results show that the solubility of asphaltene reaches the minimum at the bubble pressure. To reduce the damage of asphaltene deposition,the formation pressure should be maintained at near bubble pressure. Simulated production for one year,the results show that the pressure drop funnel steep obviously when considering the asphaltene deposition,which is caused by the increase of seepage resistance.

关 键 词：沥青质沉积 相平衡 Flory-Huggins溶解理论 流固耦合 数值模拟 

分 类 号：TE345[石油与天然气工程—油气田开发工程]