Solid Expandable Tubular Technology: The Value of Planned Installation Vs.Contingency

摘要

Narrow pore pressure/fracture gradient windows oftennecessitate additional casing strings to reach deeper objectivedepths. Operators are constrained by the number of strings ofconventional casing that they can run through subsea orsurface wellhead equipment. Planning solid expandabletubulars into the well design allows the operator to runadditional casing strings and drill to deeper objectives.Using a solid expandable tubular system in the uppersections of the well design preserves hole size from the onsetand allows more casing strings to be run without having topush casing points to the frac-gradient limit. Preserving holesize contributes to drilling efficiency, reduces equivalentcirculation density (ECD), and minimizes risk associated withsmall hole size in deeper sections of the wellbore.Another application for solid expandable tubulars is withsurface stack technology. Early surface stack systems weredesigned around a subsea stack blowout preventer (BOP)system placed on top of a 13-3/8 in. Drilling riser. After settingthe 13-3/8 in. Riser, only one or two casing strings could be runthrough the riser, which precluded reaching deeper geologicobjectives.This paper will look at two case histories. The first casehistory compares two deepwater offset wells in MississippiCanyon. One well used expandable casing as a contingency,and the other well incorporated the casing as part of the basedesign. The second case history will evaluate a well wheresolid expandable tubular technology allowed up to threeadditional casing strings to be run in a surface stackapplication. This paper discusses how combining solidexpandable tubular technology with surface stack technologyhas pushed the technical limits of surface stack drilling intodeeper water and deeper formations.