环空注氮气稠油热采井筒中的干度变化

Dryness Changes of Wellbore in Viscous Crude Oil Production with Nitrogen Injection

蒸汽干度是影响注汽开采稠油工艺的主要参数,本文运用传热学、热力学及流体力学等学科知识,提出一种蒸汽干度的计算方法。首先分析了注汽井筒的传热过程,并在考虑压力变化的前提下建立了数学模型,计算得出井筒热损失量,最后确定井筒中任意处的蒸汽干度。以海底蒸汽井为例,分析井中干度随深度的变化情况,为热采注汽系统的现场工艺设计提供参考。

In the process of steam injection,the steam flows along the wellbore.The heat transfer process includes heat conduction,heat convection and radiation.With the knowledge of the heat transfer,fluid mechanics and thermodynamics,this paper analyzes the heat transfer process of wellbore,establishes the mathematical model of heat transfer with consideration of the borehole stress changes and calculates the heat loss of wellbore.Then dryness changes at each point of wellbore can be calculated.It studies the dryness＇ changes with variations of depth in the undersea steam well to provide reference for the on-site technologic design of steam injection system.