Usefulness of Steel or Rubber Drillpipe Protectors

Abstract

Rubber or steel drillpipe protectors are lateral supports placed on drillpipe between tool joints. Everyone knows that drillpipe protectors prevent drillpipe wear. An important fact not known is that drillpipe protectors will allow permissible hole curvatures (dogleg severity) greater than usual. The additional hole curvature allowed with the protectors is a result of their ability to reduce drillpipe fatigue and wear with no increase in casing wear. Conversely, for the same drilling conditions, drillpipe protectors can significantly increase drillpipe life. Range 3 drillpipe (45 ft (13.7) long) has the advantage of faster handling because less time is spent on connections and possibly also on round trips. Because it has the disadvantage of increased drillpipe wear and fatigue, very little Range 3 drillpipe is used today. With drillpipe protectors, the advantage of Range 3 drillpipe can be retained, without this disadvantage. Greater permissible hole curvature (dogleg severity) when drillpipe protectors are used (on either Range 2 or Range 3 drillpipe) may permit carrying heavier bit weights. The result should be faster drilling and reduced drilling cost.