1. Internationalization strategy: CNOOC, as a state-owned oil enterprise in China, mainly engages in the international market. The adoption of US dollar settlement can better integrate with the international market, improve international competitiveness and further promote the internationalization strategy.

2. Currency stability: Compared with RMB, the US dollar has higher stability in the international monetary system. The use of US dollar settlement can reduce the impact of exchange rate fluctuations on enterprise operations and reduce foreign exchange risks.

3. Trading partners: CNOOC's main trading partners are international oil companies and consumers. These trading partners usually use US dollars for settlement, so CNOOC can better cooperate with trading partners and simplify the transaction process by using US dollars for settlement.

4. Financial management: Using USD to settle accounts can improve the financial management efficiency of CNOOC. Because the US dollar is the universal currency, enterprises can prepare financial statements and manage funds more easily.