水平井注蒸汽传热和传质分析

利用质量守恒、动量守恒和能量守恒的原理.推导了水平井注蒸汽过程中.水平井段内汽液两相变质量流的数学模型,并用数值解的方法计算了水平段内蒸汽质量传递和热量传递的规律.结果表明,在注汽参数一定的情况下.水平井段各处吸入蒸汽数量和热量并不相等.蒸汽压力沿井筒变化不大.但干度变化较大.一定完井条件和油藏条件下.随注汽参数的改变。会有三种情形发生:(1)蒸汽只能达到水平井的上半部而不能到达井底;(2)蒸汽刚好到达水平井的井底;(3)蒸汽到达井底后仍有剩余.为了充分利用水蒸汽.因此.必须保证蒸汽注入参数、井结构和油层的互相协调.提出了通过布孔来实现水平井均匀吸汽的建议.并提出了布孔设计方法.

ANALYSIS ON MASS AND HEAT TRANSFER IN HORIZONTAL WELLBORE OF STEAM INJECTION WELL

Based on mass, momentum and energy balances a mathematical model was developed to simulate the flow of wet steam in a horizontal wellbore. The steam flow rate. steam quality and pressure along the horizontal wellbore are calculated. It is found that the change of pressure is small, and the quality changed greatly. At given steam injection parameters and wellbore constructions, following three cases may occure: (1) The injecting pressure is greater than that of the steam rate demands, the steam goes into the reservoir and can not arrive the bottom hole: (2) The injecting pressure is just sufficient to make the steam go into the well bottom: (3) The pressure is lower than that of flow rate required. Part of steam is remained at well bottom. For increasing the recovery of heavy oil with injected steam in a horizontal well, the injecting parameters must match the well construction and reservoir conditions.