非均相海水速溶粘弹驱油体系设计及研究

Design and research of heterogeneous seawater instant viscoelastic oil displacement system

本研究针对高盐、高矿化度海上油田,开展非均相海水速溶粘弹驱油体系设计及性能优化。研发的海水速溶聚合物ZJHP通过分子改性,赋予聚合物微嵌段结构,在海水中30min内快速溶解,粘度保留率达到85%以上;研发的粘弹颗粒驱油剂ZJWQ通过多官能团引发、控制交联度,形成三维网络与高分子支化链共存结构,ZJWQ初始粒径200μm,吸水膨胀,在海水中分散透明无沉淀,具有深部液流转向、扩大波及体积作用。非均相海水速溶粘弹驱油体系能够发挥速溶聚合物与粘弹颗粒的协同作用,由海水速溶聚合物ZJHP与粘弹性颗粒驱油剂ZJWQ按照0.15%的浓度百分比等体积复配(0.15%ZJHP+0.15%ZJWQ)形成,岩心驱油效率评价提高采收率27.74%,高于单一ZJWQ、ZJHP驱油效率。海上油田应用实例表明,驱油体系增油降水效果明显。

The purpose of this research is to design and optimize performance for the heterogeneous seawater instant viscoelastic oil displacement system,focusing on the offshore oil fields with high salinity and high salinity.The developed seawater instant polymer ZJHP,through molecular modification and giving the polymer a microblock structure,dissolves quickly in seawater within 30 minutes with a viscosity retention rate reaches over 85%;the developed viscoelastic particle oil-displacing agent ZJWQ,by triggering multifunctional groups and controlling the degree of cross-linking,forms a coexisting structure of three-dimensional network and polymer branched chains.ZJWQ has an initial particle size of 200um that swells with water and is transparently dispersed in seawater without precipitation.It has the effect of deep liquid flow diversion and expansion of sweeping volume.The heterogeneous seawater instant viscoelastic oil displacement system can exert the synergistic effect of the instant polymer and viscoelastic particles,formed by seawater instant polymer ZJHP and the viscoelastic particle oil displacement agent ZJWQ compounded in equal volume at a concentration of 0.15%(0.15%).ZJHP+0.15%ZJWQ),and the core displacement efficiency evaluation improves the recovery rate by 27.74%,which is higher than the single ZJWQ and ZJHP displacement efficiency.Application examples in offshore oilfields show that the oil displacement system has an obvious effect of increasing oil and precipitation.