| 摘要 |
A method of lowering a structure 10, e.g. a pipe, through water and installing that structure 10 at a subsea location comprises the structure 10 carrying a denser than water ballast material 26, such as sea salt, which can be dry or wet in its ballasting state. Upon being lowered with the aid of the ballast material 26, the structure 10 is anchored at the subsea location. Water is then introduced to dissolve, suspend or dilute the ballast material 26 and it is evacuated or dispersed from the structure 10 in a liquid or fluidised form. For example, a solution or suspension of the ballast material 26 may be entrained in a flushing flow of water through and from the internal space of a pipe or other hollow structure. The internal space is then available to perform another, primary function in subsea operation of the structure, for example as a flowline to convey oil or gas. The flushing flow of water may be controlled and driven via valves 30 and pumps 32. A sensor can be used to determine the composition of fluid emanating from the structure 10. |
