During the operation several downhole complications took place, such as collar break, cone break off, drill pipe sticking, lost circulation, caving and eccentrically worn drill pipe.
英
美
- 该井在施工中发生了断钻铤、掉牙轮、卡钻事故和井漏、井壁失稳、钻具偏磨等复杂情况。