致密砂岩油藏注空气低温氧化机理及组分变化规律研究  

The Study on the Mechanisms of Low Temperature Oxidation and the Law of Fluid Component Variation during Air Injection in Tight Sandstone Reservoirs

作　　者：王涛 董海鹏 Wang Tao;Dong Haipeng(Zichang Oil Production Plant of Yanchang Petroleum(Group)Co.,Ltd.,Shaanxi,716000)

机构地区：[1]延长石油(集团)有限责任公司子长采油厂,陕西716000

出　　处：《当代化工研究》2021年第16期32-34,共3页Modern Chemical Research

基　　金：国家自然科学基金“蒸汽+非凝析气热力泡沫在多孔介质中的运移及滞留机理”部分成果(51104165)。

摘　　要：为有效提高采收率,对延长油田某致密砂岩油藏原油开展注空气低温氧化研究。联合运用静态低温氧化装置及气相色谱等测试手段分析低温氧化反应后气体组成和原油物理化学性质变化规律等。实验结果表明:原油氧化的速度对温度非常敏感,在相对较低的温度与压力下,原油的氧化速度较慢。在较高的温度下,空气对原油的氧化能力较强。当压力一定时,随着温度的升高,原油氧化后空气中的含氧量呈现明显下降,体系中CO_(2)含量的变化与氧气含量呈现明显的相关性,随着温度与压力的增加而逐步增大,CO_(2)增加的百分比小于氧气减少的百分比。随着温度、压力的升高,氧气消耗量快速上升,在相同的温度下,高压体系的耗氧量明显大于低压体系。压力越高,溶解于原油中的氧气越多,而温度越高,原油与氧气的反应速度越快。初期空气中的氧气百分含量高,溶解于原油的氧气量也较高,后期随着氧气的消耗,空气中的氧气百分比下降,溶解于原油的氧气量减少,反应速度逐渐下降。高温下更多的长烃链断裂成了短烃链,CH_(4)随着氧化反应的进行含量不断上升,随着温度、压力的上升,CH_(4)的含量越高。同时利用数值模拟验证了实验的准确性。该研究成果对致密砂岩油藏空气驱具有一定的借鉴意义。In order to effectively improve oil recovery,a study on low temperature oxidation of crude oil was carried out for a tight sandstone reservoir from Yanchang Oilfield.The variations of gas components and oil physicochemical properties were analyzed by means of static low temperature oxidation apparatus and gas-phase chromatography devices.The experimental results showed that the oxidation rate of crude oil was very sensitive to temperature and it was slow under a condition of relatively low temperature and pressure.The oxidation ability of air was very stronger at higher temperatures.When the pressure was constant,the oxygen content in air obviously decreased as the temperature increased after the oxidation reaction.The content of CO_(2) was obviously related to the content of oxygen.The content of CO_(2) gradually rose and the consumption of oxygen sharply enlarged with temperature and pressure increasing,but the reduced percentage of CO_(2) was lower than the incremental percentage of oxygen.At the same temperature,the consumption of oxygen was obviously greater under higher pressure than lower pressure.Greater pressure made more oxygen dissolve into crude oil but higher temperature made faster reaction rate between oxygen and oil.In the initial stage,the percentage of oxygen was higher in air,so more oxygen was dissolved into crude oil.However,in the later stage,the percentage of oxygen decreased resulted in lower dissolution of oxygen and slower reaction rate with crude oil.At high temperature,more hydrocarbons of long chain broke into short chain ones,which led to a higher content of CH_(4).The content of CH_(4) gradually increased with temperature and pressure increasing.These results are very usefully to guide a wide application of air flooding in tight sandstone reservoirs.

关 键 词：注空气 致密砂岩油藏 低温氧化 族组分 气相色谱 

分 类 号：TE341[石油与天然气工程—油气田开发工程]