Pick up drill stem test tool.

提起钻柱测试工具。

DST (drill Stem test), a fast test for show of oil and gas while drilling.

即中途测试，是指油井在钻井过程中，对有。

The longer the single drill pipe, the lesser the critical compressive force of drill stem.

钻杆的单根长度越长，钻柱所能承受的临界载荷越小。

Drill stem tests are taken from some Wells almost immediately after drilling and completion operations.

有些井刚钻完并进行完井作业后，就立即采取钻杆测试。

Therefore the nonlinear lateral free vibration of drill stem is investigated by the perturbation method.

分析公式表明， 钻柱横向线性振动仅是钻柱横向非线性振动的一种特殊情况；