红河油田长8油藏减氧空气驱注气参数综合优化
Comprehensive optimization of gas injection parameters for oxygen-reduced air flooding in Chang 8 reservoir of Honghe oilfield
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摘要: 为探索并研究减氧空气驱提高裂缝–致密油藏采收率的可行性,以增油量、换油率、吨油成本为评价指标,应用双重介质多组分数值模型,综合室内实验、油藏工程等方法和现场实施工艺条件,开展了减氧空气驱注气参数的优化研究。结果表明:注入氧含量为5.00%的减氧空气,产出气氧含量最高为3.95%,安全可控且减缓腐蚀速率,可以达到最佳的经济效益;优化空气/泡沫段塞比为5︰1,可较好地起到延缓气窜及扩大波及体积的作用;优化单井日注气量为1.5×104 Nm3,注气压力为20~25 MPa,总注入气量控制为4 000×104 Nm3。该研究成果在试验井组应用,预测能取得较好的经济效益,为深化减氧空气驱应用研究,提高裂缝型–致密油藏的采收率奠定了技术基础。Abstract: In order to explore and study the feasibility of improving the recovery rate of fractured-tight reservoirs by reducing oxygen air flooding, a dual medium and multi-component numerical simulation model is applied, and the evaluation indexes are oil increment, oil change rate and oil cost per ton, combined with the on-site implementation process conditions. The results show that when the oxygen content of injected gas is 5%, the best economic benefit can be achieved and the highest oxygen content of the produced gas is 3.95%. It is safe, controllable and the corrosion rate is slowed down. To prevent gas channeling, the optimized ratio of air/foam slug should be 5:1, which can delay gas channeling and expand sweep volume. The daily gas injection volume of a single well is optimized to be 1.5×104 Nm3, the gas injection pressure is 20~25 MPa, and the total injection volume is controlled to be 4 000×104 Nm3. The research results in the well group can achieve good economic benefits, which lays a technical foundation for deepening the application of oxygen-reduced air flooding and improving the recovery factor of fractured tight reservoir.