Research On Optimization Of Cathodic Protection Potential Of Oil And Gas Pipelines Based On Heuristic Algorithm

With the rapid development of the petrochemical industry,the laying distance of oil and gas pipelines is getting longer and longer,and pipeline corrosion protection is becoming more and more difficult.For long-distance buried oil and gas pipelines,the transmission distance is long and the corrosive environment is complex,which can easily cause soil corrosion.In severe cases,it can cause corrosive perforations,cause oil and gas leakage,and threaten human safety and cause a lot of economic losses.Therefore,we must increase protection.For long-distance pipelines,a protection method combining a protective layer and an external current cathodic protection is often used.For external current cathodic protection,a reasonable anode position needs to be set.Appropriate cathodic protection anode positions can reduce the corrosion rate of the pipeline,but evaluating all anode positions based on actual experience is a time-consuming process.At the same time,in order to detect the cathodic protection effect,we need to monitor the potential distribution along the pipeline in real time.At present,manual inspection is often used to obtain the effective potential,which requires a lot of manpower and material resources,and the effect is not good.In order to solve these problems,based on the principle of electrochemical corrosion and protection,this paper uses external current cathodic protection technology,combined with numerical simulation technology,mainly the boundary element algorithm and heuristic algorithm mainly to improve genetic algorithm and COMSOL 3D modeling technology.The subject is studied as follows:First,the boundary element algorithm is combined with electrostatic field theory,electrochemical theory,Green's formula,radial integration method,etc.to model the cathodic protection system of oil and gas pipelines,and the boundary integral equation of the pipeline is obtained.The cross-section potential changes,and the pipeline unit is used to discrete the pipeline to obtain the set of potential equations at each point.Then,the effects of the number of anodes,the placement of the auxiliary anode,and the soil resistivity on the cathodic protection effect were studied.The results were as follows: the soil environment around the pipeline,the location and method of the burial of the anode will affect the potential distribution on the surface of the pipeline.Therefore,these factors shouldbe considered when designing a cathodic protection system.Secondly,an improved genetic algorithm was used to optimize the location of the anode.Based on the optimization results,the existing boundary element model and COMSOL Multiphysics simulation software were used to 3D model the buried pipeline cathodic protection system to visualize the potential distribution along the buried pipeline.The effects of different anode numbers,anode embedding methods,and stray currents on the potential distribution along the pipeline were studied.The same results were obtained by comparing and analyzing field measured data,and it was concluded that the anode embedding locations optimized by the improved genetic algorithm can On-site engineering construction can provide a theoretical basis.Finally,in order to achieve real-time monitoring of the potential along the pipeline,a distributed potential monitoring system for cathodic protection of long-distance pipelines was invented,real-time monitoring of long-distance transmission of information,and distributed control of the cathodic protection stations by the main control center To achieve better cathodic protection.