Transocean Ltd. (NYSE: RIG) said April 1 it will scrap the GSF Aleutian Key and Sedco 707 rigs, which are held for sale.

Scrapping the rigs will entail a non-cash charge of $90 million to $100 million, net of taxes.

The Switzerland-based company said it will scrap 18 floaters in all, and might identify other rigs to be scrapped as it evaluates its fleet’s long-term competitiveness.