Application research of hydraulic internal cutter and centralizer in down-hole accident treatment for offshore drilling

Abstract:

During the CPT static borehole testing operations conducted by the Ocean Geological Survey No.17 drilling vessel in the offshore area， long-term retention of drill pipes in the borehole caused borehole wall instability and collapse， resulting in issues such as pipe sticking and pipe burial during tripping out. Based on the equipment and technical methods employed in this engineering case study， this paper conducts an applied research on the combined application of centralizer and hydraulic internal cutter， provides a detailed exposition of the internal structure and operating principle， as well as practical experience gained in handling borehole-related incidents， which can serve as valuable references for addressing similar accidents.