油气田开发无人化、少人化已成为发展趋势,特别是边际小型油气田的开发更是如此。海上无人平台油气海管置换方案直接影响海管的安全运行。近年来，在渤海边际油田无人平台海管置换方面做了大量探索,形成正向置换、反向置换和循环置换三大类六种海管置换方案。各方案具有一定的适应条件和应用场合：正向置换和反向置换主要用于气油比不高的衰竭式边际油田开发；循环置换主要用于注水式或大气油比衰竭式边际油气田开发。在实际工程中,应结合油田周围可依托设施情况、无人平台工艺方案、油气物性、海管长度等情况,从操作便利性、经济性和技术成熟度进行综合对比,确定最佳的置换方案。形成的各置换方案保障了海上无人平台油气海管的安全运行，推动了渤海边际油田的有效开发。

At present, there is a tendency to develop oil and gas fields with unmanned and lightly manned operating facilities, especially for small marginal oil and gas fields. The displacement procedure of the oil and gas pipeline for unmanned offshore platform has a direct impact on the operation safety of the pipeline. Bohai oilfield explores with a great deal of schemes and procedures in the displacement of the subsea pipeline for the unmanned platforms. Different displacement methods have been formulated with varying procedures and reliability; and each scheme has its own favourable conditions and application scope. Among them, the cyclic displacement is mainly used in the waterflood development or the depleted marginal field development with high gas-oil ratio (GOR); while the forward displacement and reverse displacement are mainly applied in the depleted marginal field development with low GOR. In practice, the optimal displacement scheme should be determined by comprehensive comparison of operational convenience, economics aspects and technical maturity, incorporating factors such as availability of supporting facilities around the oil field, process scheme of unmanned platform, oil and gas physical properties and the length of subsea pipeline. The formed replacement schemes ensure the operation of unmanned platform oil and gas subsea pipeline safely and promote the effective development of marginal oil fields in the Bohai Bay.