双弯螺杆降斜时的钻柱强度分析

在浅层水平井钻进过程中,由于油层浅,造斜段相对较短,如果实钻轨迹偏差较大,就没有了纠正的余地。因此在实际的设计或施工中,若造斜率过大,需短程反向安放双弯螺杆钻具降低造斜率。文中以固体力学有限元理论为基础,建立了弯曲井眼中,反向安装双弯螺杆钻具的有限元力学模型,用此模型分析了下部钻具组合的应力场,并对反向安装的双弯螺杆钻具组合的强度进行了评价。现场应用表明,该分析方法的结论是合理的,能够用来指导现场。

Drill Stem Strength Analyzing While Dropping With Double-Bent Screw Drills

During shallow horizontal well drilling, the shallow oil reservoir results a relatively short building up section, and if large deviation occurs in field drilling, there will be little margin for correcting. In case of that large building rate appears in the plan or field drilling, revere connecting of the double-bent screw drill is then proposed to reduce the building rate. Based on the solids dynamics finite element theory, a dynamics model of reverse connecting of the doublebent screw drill in the deviated hole is established. The stress field of bottom hole assembly, and the drill stem strength is analyzed and evaluated using this model. Using of this model proves it to be reasonable and valuable for field drilling.