【摘要】 水下采油树作为水下生产系统的重要组成部分，安装于水下油气井口的顶部，能够实现水下井口与水下管汇等装备的连接。国内水下采油树常用的下放安装方法有钢丝缆绳安装法和钻杆安装法。由于海洋风浪流载荷复杂多变以及钢丝缆绳和钻杆强度低等因素，水下采油树的下放深度受到限制，下放安装过程难以把控。为此，基于波流联合作用理论，通过OrcaFlex软件建立了水下采油树模拟仿真模型，围绕海洋石油708工程船与海洋石油981深水半潜式钻井平台（简称海洋石油981），针对钢丝缆绳安装法和钻杆安装法，考虑安装船的吊机能力、半潜式平台的顶驱能力、钢丝缆绳和钻杆的强度等因素，研究了不同海况下水下采油树的极限下放深度。同时，针对不同下放深度，分析了2种下放安装方案中采油树的运动响应机理，得到了采油树入水、穿越飞溅区、进入深水区域全过程的运动响应情况。研究结果显示：当作业水深超过1 000 m时，钢丝缆绳安装法的稳定性较低，超过1 500 m时不能满足下放要求；水下采油树钻杆安装法的作业能力较强，安装水深可超3 000 m，更加适用于重型水下装备的安装。研究结果可为我国南海海域水下油气开发的海试安装提供指导。更多还原

【Abstract】 Subsea Christmas tree is an integral component of subsea production system. It is installed at the top of subsea wellhead and connects the subsea wellhead to subsea manifold. In China, the wireline method and the drillpipe method are commonly used to lower and install subsea Christmas trees. Due to the complex and variable wind, wave, and current loads in the sea, as well as the low strength of wirelines and drillpipes, the lowering depth of subsea Christmas tree is limited, and the lowering and installation process is difficult to control. Based on the theory of wave-current interaction, a simulation model of subsea Christmas tree was established using the OrcaFlex software. For the Offshore Oil 708 engineering vessel and the Offshore Oil 981 deepwater semisubmersible drilling platform, based on the wireline and drillpipe methods, the maximum lowering depth of subsea Christmas tree under different sea conditions was studied with consideration to the crane capacity of the installation vessel, the top drive capacity of the semi-submersible platform, and the strength of wireline and drillpipe. Moreover, the motion response mechanism of the subsea Christmas tree in two lowering and installation schemes was analyzed for different lowering depths, and the motion responses of the subsea Christmas tree in the whole process from contacting the water to passing through the splash zone and finally to entering the deep water area were obtained. The results show that the wireline method operates with low stability when the water depth exceeds 1,000 m and fails to meet the lowering requirements when the water depth exceeds 1,500 m. In contrast, the drillpipe method has a stronger operational capability to enable the subsea Christmas tree to be installed at water depths exceeding 3,000 m, making it more suitable for the installation of heavy subsea equipment. The research results provide a guidance for the sea trial installations in subsea oil and gas development in the South China Sea.更多还原