蒸汽-氮气混合驱井筒沿程参数计算模型  

A CALCULATION MODEL FOR WELLBORE HEAT LOSS CONSIDERING NITROGEN-STEAM INJECTION

作　　者：刘刚 

机构地区：[1]中石化江汉油田分公司第四石油机械厂,湖北荆州434023

出　　处：《新疆石油天然气》2017年第4期68-73,共6页Xinjiang Oil & Gas

基　　金：国家科技"十二五"重大专项(2011 ZX 05010-002)

摘　　要：氮气辅助蒸汽驱开采稠油油藏能够有效提高蒸汽的热能利用率,但由于氮气的存在导致常规计算蒸汽驱井筒沿程热损失和压降模型已经不再适用。针对氮气与蒸汽在井筒中的二元两相流动,在充分考虑井筒传热和流动理论的基础上,建立了氮气-蒸汽混注过程中井筒沿程热损失和压降的计算模型,得到了氮气-蒸汽混注过程中井筒沿程参数的变化,并分析了井口氮气注入流量和井口蒸汽干度对井底总压力、蒸气分压和干度等相关参数的影响。计算结果表明:随着注入井深的增加,氮气-蒸汽混合物总压力和蒸汽分压增加,混合物温度升高,累积热损失增大。井口氮气注入流量的增加能够减小蒸汽分压,提高井底蒸汽干度,从而减小井筒累积热损失。说明氮气能够有效提高注入蒸汽的热能利用率,该模型能够准确计算氮气参与下的蒸汽热损失。Nitrogen foam-assisted steam flooding for heavy oil reservoir can effectively improve the steam utiliza-tion. However, due to the existence of nitrogen, the conventional calculation model for wellbore heat loss andpressure drop is not suitable. Based on the theory of two phase flow of nitrogen-steam and wellbore heat transfer,the calculation model of the wellbore heat loss and pressure drop along the process of the mixture injection of ni-trogen and steam is established. The variation of the on-way parameters in the process of nitrogen-steam injec-tion is obtained. The effects of the nitrogen flow rate and steam quality at well head on the related parameters ofwell bottom were discussed. The results showed that as the mixture was injected into wellbore, the mixture pres-sure, steam partial pressure and the mixture temperature increased, so that cumulative heat loss increased. In-creasing nitrogen flow rate at well head was helpful to decrease the steam partial pressure, improve the steamquality and decrease the shaft heat loss. The nitrogen has good heat insulation effect, and can effectively improvethe utilization rate of the heat energy.

关 键 词：氮气-蒸汽混注 压降 蒸汽分压 井筒热损失 井底参数 

分 类 号：TE357.4[石油与天然气工程—油气田开发工程]