潜孔锤跟管钻进套管断裂分析及结构改进

Failure Analysis and Structure Improvement of DTH Drilling with Casing

摘要:

潜孔锤跟管钻进技术是解决复杂地层钻进的一种有效手段，但在实际应用中存在套管断裂失效等问题。对套管受力进行有限元分析表明，由于套管退刀槽自身尺寸和位置的关系，导致疲劳破坏。针对这一问题，提出加长管靴长度，以减弱冲击载荷对套管的影响。对比改进前后的有限元计算结果，套管退刀槽处应力、应变明显下降，受力状况得到改善。现场试验结果表明，改进方案切实有效。

Abstract:

DTH drilling with casing is an effective means to deal with drilling in complex strata. However, the case is usually broken in practical application. Based on the finite element analysis, it is the relation between size and position of case tool escape that causes the case fatigue damage. To solve this problem, pipe shoe was lengthened in order to weaken the impact on case. Compared to the original design, stress and strain of the improved case were dramatically declined with force status greatly improved. The results of field test indicate that the improving scheme is practical and effective.