Application Of The Vertical Tension Anode System In The Cathodic Protection Of Jacket Platform

Jacket platform plays an important role in offshore oil and gas,and it's cathodic protection method is mostly sacrificial anode.During the construction of the jacket,the sacrificial anodes are welded.As the sacrificial anode has a certain design life,as time goes,the sacrificial anode will gradually be consumed out,leaving the jacket platform in a non-cathodic protection state.If the jacket platform can continue to produce oil and gas production,it must install new corrosion protection equipment.The installation of an impressed current cathodic protection system is a relatively good choice because of low cost and easy installation.The ICCP system has a variety of forms,and the tensile anode system has become the choice of many cathodic protection for over-age service ue to its reliable structural design,uniform protection,relatively low construction difficulty and cost.Based on the study of the tension anode system,the install position of the tension anode system is designed based on the demand of the actual jacket platform in the South China Sea.The protection potential of the four arrangement schemes is calculated by the numerical simulation of the cathodic protection of the boundary element method In order to solve the problem of motion safety of tension anode string in complicated sea conditions,tension,anchorage and limit scheme are designed,and the tensioning force,fatigue life,structural strength are checkded by calculation and analysis.Through the innovation of the general installation method,an accurate installation method for the large tonnage anchor is put forward.Firstly,this paper introduces the current cathodic protection method and cathodic protection design technology,introduces the principle of anti-corrosion to the cathodic protection of impressed current,and compares several typical ICCP systems.Then,the actual requirements of the South China Sea L-jacket platform are analyzed,and the layout scheme is designed to apply the tension string anode to the cathodic protection of the jacket platform.Through the use of the advanced numerical simulation software,the accurate position,release current are optimized,the protection potential is calculated.The calculated results are in accordance with the requirements of DNV RP B401 for the protection potential.Afterwards,in order to ensure the safety of the tension anode system in the harsh conditions of the South China Sea,the dynamic analysis,fatigue analysis,strength checking and so on are calculated and the tensioned anchor limit device is designed and calculated to ensure the safety.Finally,through the research and optimization of the traditional installation scheme,the scheme of installing the anode system of L-pipe rack is designed.By installing the electric hoist crane at the bottom of the jacket,the large-tonnage anchor weight can be transported to the inner space.Through precise positioning the anchor is decentralized and is precisely positioned.