Offshore drilling contractor Transocean is raising $550m via a senior secured note offering, with net proceeds to be used to partially finance for drillship Deepwater Poseidon.

Transocean took delivery of the drillship from South Korea’s DSME last year and immediately sent it out on a 10-year contract with Shell in the Gulf of Mexico.

The offering is expected to close February 1, with net proceeds estimated at $538m.