大牛地水平井速度管排液工艺研究与应用

Research and Application of Velocity String Drainage Technology in Horizontal Wells of Daniudi

受井身结构影响,大牛地气田水平井泡排成功率低,排液难度大,而更换小油管需压井作业,返排周期长且漏失量大,严重限制了气井产能。针对大牛地气田水平井特点和排水采气难点,研制了速度管柱作业悬挂密封装置,实现了预先放置卡瓦,减少了操作流程,解决了带压情况下速度管的悬挂、密封和剪断问题。同时确定了悬挂密封装置主要技术参数,并优选出CT70型38.1 mm速度管作为生产管柱。现场应用结果表明,速度管无需压井,施工周期短,施工成功率高,排水采气效果明显,为大牛地气田水平井排水采气工艺提供了一种新技术。

Due to the effect of wellbore structure, there is a low success rate for foam scrubbing in horizontal wells of Daniudi Gasfield. It is difficult to discharge fluid. Replac, ement of small tubing requires killing operation. The flowback cycle is long and the leakage is large. As a result, the formation is polluted remarkably and the production capacity is restricted severely. In light of the feature of horizontal wells in Daniudi Gasfield as well as the difficuhy in water drainage and gas recovery, the hanging sealing device for velocity string operation was developed. The prestaging of slips was achieved. The operating procedures were reduced. The hanging, sealing and shearing problems of velocity string under pressure were solved. Meanwhile, the main technological parameters for hanging sealing device were determined. The CT70 Ф38.1 mm velocity string was optimized as the production string. The field application shows that the velocity string requires no well killing. The operation period is short. The operation success rate is high. And the effect of water drainage and gas recovepy is obvious.