低渗透气田水平井钻井(完井)液技术

HORIZONTAL WELL DRILLING AND COMPLETION FLUIDS TECHNOLOGY IN LOW PERMEABILITY GAS FIELD

针对低渗透气田平井钻井过程中的井壁稳定、钻头泥包、及保护储层技术难题,室内研发了用于斜井段的双钾盐聚合物钻井液体系和用于长水平段配合裸眼完井工艺特点的无粘土低伤害暂堵钻井(完井)液体系,并在长北气田20余口分支水平井成功应用。结果表明,斜井段易塌层平均井径扩大率低于20%,244mm技术套管均安全顺利下达窗口,这种尺寸套管及其下深在长庆油田尚属首次。水平段安全顺利钻过2245m水平段分支,裸眼完井并直接气举投产,获得无阻流量超过200×104m3/D的单井高产,创造了长庆气田新纪录,保护储层效果明显。

In order to solve such technical challenges in horizontal well drilling of low permeability gas field as borehole wall sta bility,bit balling and reservoir protection,double potassium polymer drilling fluid has been developed which is mainly used in the deviated intervals,and clay free low damage temporary plugging drilling and completion fluids have been developed as well which are used in long horizontal intervals and open hole completion wells.It has heen successfully used in more than 20 multilateral horizontal wells in Changbei gas field.The results indicated that the average hole enlargement rate is lower than 20% in deviated internal of easy collapse formation,244mm technical casing can be safely and successfully run down and set on the pre-aet position,which is the first time for such size casing to run in such depth in Changqing oil field.The horizontal interval has been sucessfully drilled through 2245m horizontal lateral,with open hole completion and gas lift production,each well with open-flow capacity of more than 200 104m3/d,which sets a new record in Changqing gas field,with significant effect in reservoir protection.