海上稠油火烧油层物理模拟实验研究

Experimental Study on Physical Simulation of In-situ Combustion in Offshore Heavy Oilfields

为探索海上稠油火烧油层开发的可行性,针对渤海稠油油藏开展了火烧油层物理模拟实验。根据石油沥青组分测定法,分析渤海稠油原油组分;通过热失重与扫描量热同步热分析仪测试活化能等高温氧化反应动力学参数;采用一维燃烧管实验模拟评价燃烧稳定性及驱油效果。研究结果表明,渤海稠油组分特征与国内陆上油田相似;稠油高温氧化活化能为157 kJ/mol,与陆上油田相近;油藏火驱前缘推进稳定,燃烧前缘最高温度773 K左右,出口CO2浓度长期稳定在12%以上,高温氧化燃烧状态良好;火烧驱油效率95.1%,空气油比548m^3/t,驱油效果较好。研究成果为海上稠油油藏火烧油层开发提供技术支持。

This study has conducted a physical simulation experiment on the in-situ combustion of offshore heavy oil in the Bohai heavy oil reservoir region to explore the possibility of further development of the in-situ combustion.It has analyzed the composition of crude oil in the Bohai heavy oil region using the method employed for determining the components of asphalt and crude oil.The kinetic parameters of high-temperature oxidation reactions,such as the activation energy,were evaluated using the thermogravimetric analysis and scanning thermal analyzer.This work has used a one-dimensional combustion tube for the simulation experiment to evaluate the combustion stability and oil displacement efficiency.The results demonstrate that the composition of crude oil in the Bohai heavy oil region is similar to that of the onshore oil fields in China's Mainland.The high-temperature oxidation activation energy of heavy oil is 157 kJ/mol,which is similar to that of the onshore oil fields;the burning front moves forwards steadily,and the highest temperature of the combustion front is estimated at approximately 773 K.The concentration of CO2 at the outlet is estimated over 12%,and the high-temperature oxidation combustion is observed to be good.The oil displacement efficiency is estimated at 95.1%,and the air-oil ratio is 548 m^3/t,It is established that the oil displacement efficiency is fairly satisfactory.