低渗透油藏空气驱氧化特征及驱油效果评价
Oxidation Characteristics and Oil Displacement Effect Evaluation of Air Flooding in Low Permeability Reservoirs
骆晨 1刘慧卿 1柏宗宪 2王转转 3王亮亮 4张雅倩1
作者信息
- 1. 中国石油大学(北京),北京 102249
- 2. 中国石油冀东油田分公司,河北 唐山 063004
- 3. 中国石油青海油田分公司,甘肃 敦煌 736202
- 4. 中国石油大学(华东),山东 青岛 266580
- 折叠
摘要
针对低渗透油藏高压注空气开发过程中原油氧化机理不明确和增油潜力预测难的问题,开展低温氧化实验和长岩心注空气驱物理模拟实验,分析不同油藏条件下氧化反应前后油气组分变化差异,揭示原油低温氧化反应特征和规律,探究低渗透油藏水驱转注空气驱开发潜力,评价注空气驱驱油效果.研究表明:随着氧化温度的升高,耗氧量增加,氧化后油样轻质组分减少,中质和重质组分增加;含水饱和度过高使原油氧化的热效应降低;原油氧化敏感性因素从大到小依次为压力、温度、含水饱和度.空气驱具有较好的驱油效果,驱油效率可达41.20％,但注气压力过高易导致气窜;水驱至经济极限后转空气驱可以提高驱油效率,但空气驱阶段驱油效率增长幅度较小,最终驱油效率为50.92％.在实际开发过程中,应采用减氧空气驱并优化注气参数,控制窜流通道形成,提高采收率.研究结果可为低渗透油藏空气驱开发提供基础理论依据和技术支持.
Abstract
In the process of high-pressure air injection development in low-permeability reservoirs,the mechanism of crude oil oxidation is unclear,and there is difficulty in predicting enhanced oil recovery potential.In order to solve these problems,low-temperature oxidation experiments and physical simulation experiments of air injection in long core were conducted to analyze the differences in oil and gas composition before and after oxidation reactions under different reservoir conditions,reveal the characteristics and laws of crude oil low-temperature oxidation,inves-tigate the development transition potential from water flooding to air flooding in low-permeability reservoirs,and e-valuate the oil displacement effect of air injection.The results show that with the increase in oxidation temperature,the oxygen consumption of crude oil rises;while after the oxidation,the light components of the oil sample decrease and the medium and heavy components increase.Excessive water saturation reduces the heat effect of crude oil oxi-dation.The sensitivity factors of crude oil oxidation in terms of sensibility from large to small are pressure,tempera-ture,and water saturation.So,air flooding has a better oil displacement effect,with an oil displacement efficiency of up to 41.20％.However,excessively high gas injection pressure can cause gas channeling.After reaching the eco-nomic limit by water flooding,development mode switched to air flooding can improve oil displacement efficiency,but the increment of oil displacement efficiency during the air flooding is relatively small,with an ultimate oil dis-placement efficiency of 50.92％.Therefore,in actual development process,oxygen-reduced air flooding should be a-dopted,and gas injection parameters should be optimized so as to control gas channeling and enhance oil recovery rate.The research results can provide a theoretical basis and technical support for the development of low-permea-bility reservoir by air flooding.
关键词
低渗透/氧化/组分/空气驱/驱油效率Key words
low-permeability/oxidation/composition/air flooding/oil displacement efficiency引用本文复制引用
基金项目
国家自然科学基金企业创新发展联合基金(U20B6003)
中国石油大学(华东)研究生创新基金(23CX04050A)
出版年
2024
国家科技期刊平台
NSTL
万方数据