摘要: |
为分析注汽井油套环空充氮气和伴注氮气的隔热效果对注蒸汽的影响,根据热量传递原理和流体流动理论, 建立了井筒中伴注氮气辅助注蒸汽热采工艺中蒸汽、氮气沿并筒流动与传热的数学模型,计算了蒸汽、氮气沿井筒 的温度分布和压力分布,对比了环空充氮气和空气、充氮气和伴注氮气的隔热效果。结果表明:充氮气和充空气隔 热方式对隔热效果的影响不大;充低压隔热气体可获得较好的隔热效果;伴注氮气比充氮气隔热效果好,且随着环 空伴注氮气流量的增大,油管内蒸汽压力升高,蒸汽的热损失增大,大部分热量被氮气吸收后带入地层,而实际散失 到地层的热损失逐渐减小。 |
关键词: 热采方法 注蒸汽 氮气 环空 流动与换热 井筒 |
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基金项目:山东省自然科学基金项目(Y98A11014) |
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Flow and heat exchange laws in thermal recovery wellbore by steam injection assisting with nitrogen gas |
LI Zhao-min1,YANG Jian-ping1,LIN Ri-yi2
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(1. College of Petroleum Engineering in China University of Petroleum,Dongying 257061, Shandong Province, China;2. College of Transport & Storage and Civil Engineering in China University of Petroleum, Dongying 257061,Shandong Province, China)
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Abstract: |
In order to analyze the effect of the heat insulation methods of charged or injected nitrogen gas in the annular of steam injection wells on steam injection,the flow and heat transfer mathematical models of the steam and nitrogen flowing along the wellbore were established on the basis of heat transfer principle and flow theory. The temperature and the pressure distribution of the fluids were calculated. Annular heat insulation effects of charged nitrogen gas and air, and charged or injected nitrogen gas were contrasted. The results show that the insulation effect of charged nitrogen gas or air in annular is negligible ,the insulation method of charging with low pressure gas is well,the insulation effect of injected nitrogen gas is better than that of charged nitrogen gas. When the injecting nitrogen gas volume increases, the steam pressure will ascend, heat loss of steam will increase which is absorbed by the nitrogen gas and injected into the formation, and the actual heat loss will decrease. |
Key words: thermal process steam injection nitrogen gas annular flow and |