Underbalanced drilling (UBD) with jointed pipe has become routine in the UK sector of the southern North Sea and operators in the Norwegian sector are now introducing the same concept. Typically, the well is kept live during tripping and a rig-assist snubbing unit is employed to handle the drillpipe while pipe-light. Significant surface compressive loading is exerted on the pipe during the snubbing phase. The focus of this paper is two-fold. First we consider buckling of the drillpipe in the snubbing jack and on the drill floor when a static compressive load is applied. Thereafter, we analyze the behavior of ejected tubulars during well entry and exit under live well conditions.

Keywords:
iadc spe 77241, stripper, compression, upstream oil & gas, pipe, downhole intervention, pressure-area force, drill pipe selection, underbalanced drilling, compressive stress
Subjects:
Drillstring Design, Pressure Management, Drilling Equipment, Drill pipe selection, Underbalanced drilling, Well Intervention
Copyright 2002, IADC/SPE Asia Pacific Drilling Technology
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