A Study Of Jar Mandrel Surface Corrosion Causes And Protective Measures

In recent years, Liaohe oilfield take more drilling way to increase overall oil production due to the oil production of stand-up Wells is reduced. However, Liaohe oilfield is an underground faults, and the geological is the complex compound. In addition, the main types of oil are heavy oil. But the heavy oil buried is deeperin the Liaohe oilfield. So in the process of drilling, the drilling often is caused by underground faults,and the complicated geology in the process of drilling, the accident frequency is increased significantly, in which tool sticking takes up to a half, the jar is the better way to solve such problem.Though the jar is the better way to solve such problem. In harsh environment with mud and corrosive liquid, the mandrel is inclined to corrosion fracture under the conditions of chemical corrosion and overwork. Therefore, jar smooth degree of surface of the spindle directly affects the jar in the use of time, so research of reasons for surface corrosion is urgently needed to find out right anticorrosion measures.The mandrel of jar adopts the material of 38 CrMo. This thesis is to summarize corrosion mechanism by studying the corrosion-resistance of 38 CrMo in muddy corrosive liquid and th e XRD of corrosion morphology and corrosion products. Furthermore, find out the right prote ctive measures from the analysis of corrosion and mechanical performance of 38CrMo+ Plati ng hard chromium plating, 38CrMo+chemical plating Ni-P amorphous plating, 38CrMo+ surf ace nitriding layer.