Research On 3LPE Anticorrosion Technology Of Oil And Gas Pipeline

In recent years,with the development of oil and gas resources,3LPE corrosive technology has been widely used in buried pipelines.However,in the process of service,the failure of anticorrosive coating and the perforation of pipelines even cause oil and gas leakage and explosion,causing great economic losses and safety accidents.The reason is related to the performance of 3LPE corrosive raw materials,anticorrosive process or other reasons.In this paper,the corrosion process of 3LPE was studied,and the effects of coating speed,surface treatment of steel pipe,coating heating temperature and winding process on the corrosion performance and mechanical properties of the corrosion layer were studied by Differential Scanning Calorimetry analysis,cathodic stripping,polyethylene stretching and hot water immersion test.The results showed that: Firstly,With the increase of the coating speed,the cathodic stripping ability of the coating decreases.Combined with the change of epoxy powder,it can be seen that the reason for the increase of the stripping distance is the reduction of the curing degree of epoxy powder.Only when the coating linear speed does not exceed 1.85 m/min,the epoxy powder be fully cured.Secondly,the wettability of epoxy powder directly affects the performance of the overall anticorrosive coating.Its wettability has certain requirements for the surface anchorage depth of the steel pipe.When the anchorage depth is 65 ~75 ?m,the coating has a good ability to resist hot water immersion.When the anchorage depth is too low,it will cause a sharp decline in the cathodic stripping ability of the coating.If the anchorage depth is too high,it will increase the cost of corrosion protection.Therefore,it is advisable to control the anchorage depth at 65 ~75 ?m.Thirdly,different heating temperature affects the epoxy powder at the bottom of the infiltration ability,within a certain range,the heating temperature of 230 ? can make Cathodic disbonding resistance of coating to get better.Fourthly,four layer winding technology has great economic value,the polyethylene axial and circumferential tensile strength of the deviation,although the above five layer winding axial and circumferential tensile strength of the deviation,but lower than the standard requirements,therefore,in combination with economic value and the mechanical properties of polyethylene layer,when 3LPE anticorrosive,can use four layer winding technology reduce the processing cost.