First the discovery well was the “Ugnu No 1” — Ugnu being the shortened name of a nearby river — though it is the discovery well for the Kuparuk reservoir, not the shallower Ugnu.
Compounding the confusion, Kuparuk delineation wells were called “West Sak,” although they were
ARCO Alaska officials told the Alaska Oil and Gas Conservation Commission in 1981 that between 1969 and 1980, ARCO and other companies drilled 25 wildcat and extension wells in an attempt to define the limits of the Kuparuk accumulation.
Jim Posey, who worked on the startup team, talked about that delineation drilling in the 2001 20th anniversary Kuparuk video.
“We wanted to know how far the field extended before we filed the papers with the state, so we had them drill the perimeters of the field, starting with West Sak No. 13, 14 … and going up to West Sak 20,” said Posey, who worked on unitization for the startup team.
Posey said it was a multiple effort: they were trying to find the edge of the field, “at the same time do unitization and get this thing online by 1981, which was the target.”
The names have changed.
Production wells at the field have names beginning with Kuparuk River Unit, followed by the satellite name — Tarn, Tabasco, Meltwater or West Sak, if appropriate — and then by a pad and well number.