据ＰｅｔｒｏｌｅｕｍＥｎｇｉｎｅｅｒ报道 ,由于海上钻井的水深度越来越深 ,经营者与承包商面临决定改造旧钻机还是建造新钻机问题。据估计建造一台新钻机需 2 5～ 3 0亿美元 ,但改造一台旧钻机费用仅为 1亿美元。改造目的是提高现有钻机的能力 ,如对第二代钻机进行改造 , According to Petroleum Engineer, operators and contractors are faced with the issue of deciding whether to retrofit old rigs or build new rigs because of the deeper water depth at sea. It is estimated that 25 to 30 billion U.S. dollars will be required to build a new rig, but the cost of retrofitting an old rig will be only 100 million U.S. dollars. The purpose of the transformation is to enhance the capabilities of existing rigs, such as retrofitting of second generation rigs,