Analysis Of Casing Rupture With Finite Element

Rupture is the most dangerous form of casing failure, in many cases it would cause great economic losses in crude oil industry. Casing rupture affected by many factors is a very complex process, such as the casing itself, the material, working environment, stress state, geological factors, the casing dimensions, and defects, etc. So, the rupture is usually affected by several factors.The mechanism of casing damage and affecting factors were described in this article. The bottom-cement ring-tube model was built by parasolid modeling of ADINA to simulate the crack propagation process of cement sheath, and by changing the pipe material, diameter, wall thickness, radius to thickness ratio to analyze the failure process of the casing. The following conclusions were qotten:The yield strength of the materials that the casing used play a critical role in the stress of the casing. The greater the yield strength of the casing, the greater force the casing can withstand. Using the same kinds of materials of the casing by the formation of the shear relative displacement, in the case of the same diameter, the greater the casing wall thickness, the greater external load the casing can withstand. The same as in the material, wall thickness under the same conditions, the greater the diameter the less the ability to resist stress. Using the same materials, casing, the smaller the radius to thickness ratio,the greater the casing can withstand.Model is based on finite element software ADINA as a platform to an oil well Jinzhou field as an example, and analyse the casing rupture factors that caused by different materials and size were analyzed. It is useful for reducing the number of sets of damage in crude oil industury.