Study On Twin-lift Solution For Decommissioning Of Topside Of Jacket Platform

The north sea were explored earlier.In recent years,a large number of offshore oil and gas platforms have gradually reached their ending of service life,and the number of jacket platforms facing decommisioning is large.Because the environment of this sea area is relatively complicated and the marine environment is harsh,the water depth in some sea areas cannot meet the construction conditions of large-scale equipment.In addition,the traditional decommisioning method has high cost,long engineering period in the sea area.So it has higher requirements for shortening the engineering period.Therefore,the overall removal of the topside has become a priority option.The method of removing the topside of the offshore platform by the twin-lift method can make better use of the maneuverability of the double barge and flexibly adjust the engineering scheme according to the sea area.It is an ideal method for decommisioning.In this paper,the wave environment conditions close to the actual sea conditions are used to calculate the hydrodynamic coupling of the two barges.The differences in hydrodynamic performance caused by variables such as the direction of waves and the load conditions of the barge are studied from the frequency and time domain methods.By comparing with the results of the DP experiment,under relatively ideal sea conditions,combined with the wave close to the actual sea environment,the change in the hydrodynamic coupling performance of the barge and the amplitude analysis of the motion response are performed.In terms of force analysis,the DMU was improved.By comparing experimental data with numerical calculation data,it was concluded that the force was within a reasonable range.Finally,some guiding opinions were provided for the rationality of the actual construction.