Study On The Stowage And Securing For The Transportation Of Jack-up Drilling Platform By Semi-Submersible Vessel

With the growing of mining intensity for oil and gas resources ashore and decreasing gradually of the oil and gas reserves,ocean petroleum resources has become the focus of attention and hot spots of oil and gas exploration and exploitation.Jack-up drilling platform is one of the most important equipment for offshore oil and gas exploration and exploitation,which occupies the important position in the continental shelf waters of the oil and gas exploration and development due to its good positioning ability and operational stability.But the weight and volume of jack-up drilling platform are large,and the size of appearance is not neat.In waters from port to the operation area or operation areas in the process of conversion,the transport process has always been the focus of attention because of its no self-propelled ability.The main method for jack-up drilling platform's transportation currently is by way of the dry tug,with self-propelled semi-submersible vessel's transportation on behalf.Because of jack-up drilling platform's high center of gravity and heavy weight,using the traditional method of flexible securing has not applied to its securing work.Generally,rigid securing is adopted in this situation,and this paper will base on the way of securing to study the transportation for jack-up drilling platform by semi-submersible.This paper takes it as the research object that the jack-up drilling platform is transported by semi-submersible vessel,which mainly analyzes the feasibility of the jack-up drilling platform transited by semi-submersible vessel from the perspectives of stowage and securing.The stowage mainly considers the factors including stowing condition and stowing way of jack-up drilling platform,stability of the vessel,reducing the stress of jack-up drilling platform,arrangement of cribbing wood on deck and deck's strength and so on.It confirms the reasonable arrangement of cribbing wood by way of linear programming and gives the checking method to check the strength of cribbing wood and local strength of deck.It comes up with the checking way to check whether the securing plan of jack-up drilling platform is effective or not on the basis of in-depth study of mechanics of materials.Meanwhile it makes use of ANSYS finite element method to build model for checking the securing plan of jack-up drilling platform.At last,it proves feasible that checking the validity for securing plan of jack-up drilling platform by formula method via an instance,which will be of great importance and necessity of transportation for jack-up drilling platform by semi-submersible vessel.In this paper,the conclusion can be applied to another similar heavy cargo's transportation by semi-submersible vessel,and it also provides the reference for the semi-submersible vessel company when making stowage and securing plan for jack-up drilling platform's transportation.