During drilling the third hole section in the Xin 1 Well, fracture zones were penetrated together with wellbore caving and severe sloughing, which caused pipe sticking and thus twice sidetrack.

• 新1井三开钻进时由于钻遇破碎带地层,井壁坍塌、掉块非常严重,造成卡钻事故并因此导致两次侧钻。