| 摘要 |
<p>There is disclosed improved method and apparatus for installation of deep water subsea pipelines, wherein a pipeline (100) is flooded from one end to drive a pig unit (104) within it along its whole length by the action of hydrostatic pressure acting upon the pig, and without the need for any additional field equipment. A length of pipeline in an initial state contains a gas (102) at a pressure below the ambient hydrostatic pressure, and a pig unit sitting at an end having an entry point (106) for the flood water. The pipeline is flooded between both ends, whereby fluid is admitted progressively by operation of a flood valve (110) into the pipeline to drive the pig unit under the influence of the ambient pressure toward the far end, compressing the gas within the pipeline. An auxiliary chamber (400) is connected to the far end of the pipeline so as to accommodate the gas (102) in its compressed form substantially outside the pipeline itself.</p> |
