摘要
委内瑞拉MPE3区块油藏重油黏度高、油层厚度极大且非均质性严重,为降低热采方法的成本和碳排放量,使用自制的重油降黏剂和人造岩心进行了重油冷采新技术室内研究,考察了凝胶调剖和降黏剂对岩心驱油效果的影响。结果表明,研制的涂层降黏剂在多孔介质中可剥离重油,产生造粒降黏提高采收率的效果。通过凝胶调剖处理可与降黏剂驱替重油产生协同效应,既扩大降黏剂波及效率可接触新的重油,又有利于重油的造粒降黏。随岩心渗透率增大,泄油后的地层越易形成高渗透水窜通道。采用聚合物凝胶处理或者气体-降黏剂交替注入进行调剖,可以较大幅度地提高重油的采收率。在气液交注吞吐冷采过程中,注入的气液既增加地层能量,又可搅动地层流体,有利于涂层降黏剂与稠油混合形成低黏乳状液,便于吐出。气液交注吞吐冷采过程的采收率增量可达16.10%OOIP。
The reservoir of MPE3 block in Venezuela had heavy oil with high viscosity and oil layer with widely thickness and heterogeneities. In order to decrease the cost of thermal recovery and carbon emission, a novel cold production technology for heavy oil was studied in lab with homemade viscosity reducers and artificial cores under the reservoir condition of MPE3 block. The effect of profile control with gel treatment and viscosity reducer on oil displacement efficiency in the core was investigated. The results showed that the heavy oil in porous media could be split and then coated with the viscosity reducer to produce a phenomenon of granulating and viscosity reducing, which led to a higher oil recovery increment. If the core was treated with profile control before the viscosity reducer displacement, synergetic effect would happen both to increase sweeping efficiency of viscosity reducer to contact some more heavy oil and to boost the result of granulating and viscosity reducing. The higher the permeability of porous media, the easier the water channel passages were formed in drainage formation. The method of profile control including polymer gel treatment or alternative injection of N2 which applied together with the viscosity reducer displacement could enhance heavy oil recovery greatly. On the other hand, in the cold huff and puff process with gas liquid alternating injection, either stratum energy increased or formation fluid was stirred with gas-liquid, which made the viscosity reducer and heavy oil blend and formed emulsion with low viscosity easily. The oil recovery increment in the cold huff and puff process with gas liquid alternating injection could reach 16.10% OOIP.
出处
《油田化学》
CAS
CSCD
北大核心
2017年第3期491-496,518,共7页
Oilfield Chemistry
关键词
重油
降黏剂
造粒降黏
调剖
凝胶
提高采收率
heavy oil
viscosity reducer
granulating and viscosity reduction
profile control
gel
enhanced oil recovery
