OSX won the $263 million contract from SapuraCrest last month, to start construction of the vessel at its Acu shipyard in Rio de Janeiro state.
Seadrill and SapuraCrest agreed each would pay half of the first payment for the vessel through cash advances to the venture, Sapura Navegacao.
SapuraCrest also said it would reimburse Seadrill or its Brazilian subsidiary Seabras Servicos, that advance should the conditions precedent to the deal not be fulfilled by an agreed date.
