溶剂辅助蒸汽驱后期提高稠油采收率研究

A Study on Improving Heavy Oil Recovery by Solvent Assisted Steam Flooding in Late Stage

以辽河油田杜84块兴Ⅵ组超稠油油藏为对象,根据SAGD蒸汽汽腔操作压力,筛选与蒸汽露点温度相近的己烷作为辅助溶剂,进行单管驱替实验。研究了不同温度下,溶剂类型和浓度对稠油的降黏效果,并对比了不同浓度的己烷辅助蒸汽驱与纯蒸汽驱的驱油效率。实验结果分析了溶剂辅助对蒸汽驱后期的油汽比,剩余油饱和度和最终采收率的影响,揭示了蒸汽温度和溶剂浓度对蒸汽驱效率的影响规律。研究结果可为SAGD开发后期提高稠油开采效率、优化现场操作参数提供理论支持。

This paper takes the Xing Ⅵ Group super-heavy oil reservoir in Block Du 84 of Liaohe Oilfield as the research object,and conducts an indoor evaluation study on solvent assist as a replacement technology to improve the efficiency of SAGD production.According to the current operating pressure in the SAGD steam chamber,hexane,which has a temperature similar to the steam dew point,was screened as an auxiliary additive for SAGD.In the laboratory,we first studied the evaluation of the viscosity reduction effect of heavy oil at different temperatures,solvent types and concentrations,and carried out comparison experiments of oil displacement efficiency between hexane-assisted steam flooding and pure steam flooding at different concentrations.Through solvent-assisted analysis of water cut,remaining oil saturation and final recovery improvement degree in the later stage of steam flooding,the influence of steam temperature and solvent concentration on steam flooding efficiency are revealed.The research results in this paper provide theoretical support for using solvents to assist in improving the efficiency of heavy oil recovery and optimizing on-site operating parameters in the later stage of SAGD development.