热采水平井多点注汽工具设计与试验研究

Design and Experimental Research of Muitipoint Steam Injection Tool Used in Horizontal Well Thermal Recovery

多点注汽是改善稠油热采井吸汽剖面、提高采收率的有效工艺,蒸汽限流分配器是实现该工艺的关键工具。以热采水平井吸汽能力模型为基础,综合考虑油藏物性、井筒汽液两相流压降的影响,设计蒸汽限流分配器,实现沿水平井筒蒸汽注入量的调配。通过水平井注汽地面模拟试验,验证蒸汽限流分配器的有效性,并研究注入参数的影响。结果表明:调配蒸汽限流分配器的通流面积后,试验单元流量分布的均匀性得到明显改善,不均匀系数最大降幅为93.8%;随着泵排量的增大,流量分布不均匀系数先减小后增大;蒸汽限流分配器与封隔器的优化组合是实现水平井多点注汽工艺的有效方法。

It is effective to improve steam entry profile of thermal production well and recovery ra- tio through applying muitipoint steam injection technology. While the muitipoint steam injection tools is the key technique. Muitipoint steam injection assorted tool-vapourstream-limiting distrib- utor are designed to allocate injection rate of steam along horizontal wellbore,which is based on the steam injection model for horizontal well in heavy oil reservoir with thermal recovery. This tool also takes the physical property of reservoir and the effects caused by the pressure drop of vapour-liquid in the wellbore into consideration. The effectiveness of vapourstream-limiting dis- tributor has been verified through the overground simulation test of steam injection for horizontal well. The effects of injection parameters are also studied during the simulation test. The results indicates that the homogeneity of the profile of flowrate for test units will be improved signifi- cantly after allocating the flow area of the vapourstream-limiting distributor. To be more specific, the maximum decrease of the nonuniformity coefficient will be 93.80/oo. The nonuniformity coeffi- cient decreases and then increases, with increasing pump capacity. The optimum combination of vapourstream limiting distributor and packer is an effective method to realize multipoint steam in-jection technology.