In the Icewine prospect south of Prudhoe Bay, severe vibrations developed when crossing formation boundaries down towards the coring point. The operator decided to fly in Tomax tools with the aim of improving the situation.
The 4 ¾” OD, 10 inch stroke, X-Series AST paid for its airfare by delivering full core recovery: in mixed rock, it is paramount to avoid vibrations that can crack the laminar column inside the core barrel. If pieces of the core come free, they will most likely jam the barrel. In this case, the AST was kept in the BHA for the remainder of the well, using ordinary BHAs.
”We had 97% recovery with two 90’ barrels and 97% recovery with one 30’ barrel. We believe the AST tool contributed greatly to this success”
Erik Opstad, Operations Manager, Energy 88
The MWD data was able to document how the AST eliminated the previous vibration problems and also improved drilling efficiency (ROP).
The result from the coring was promising and the full recovery improved the accuracy of the resulting analysis.