PetroChina, Sinopec, CNOOC and other companies bidding information in which site is generally publicized?

PetroChina Bidding site is Energy One need to register to become at least a second-tier supplier to see the internal general bidding information; if it is a first-class materials need to be a first-class supplier, this also need to bid;

Sinopec Bidding site is Sinopec e-commerce network Enterprises have the appropriate qualifications to register, the annual fee seems to be 3000 it, but also the same must be invited to participate in the bidding;

CNOOC The site to find; also need to register, the annual fee is 10000

The answer is personal experience;