The recent increase in global energy consumption has led to the exploration and production of fossil fuels in deep-waters. The produced oil and gas from these remote locations is conveyed for further processing and consumption using pipelines. However, the integrity of pipeline system of transmission is threatened majorly by mechanical defects such as dent and gouge. In this work, the effect of dent size on the structural integrity of an oil and gas pipeline was studied using computational method. The pipe is modelled using ANSYS software and solved using the finite element capabilities of the software. The pipe is loaded laterally with a pressure load which causes the dent on the pipe and the pipe is fixed at one end and free at the other end to allow for the determination of hoop stress in the pipe. The results for one dent size is further used to solve for various sizes of dent and the corresponding stresses induced in the pipe were determined. The solution shows that after a dent size of 19mm the pipe will fail due to the ultimate tensile strength being exceeded.

Keywords : Mechanical Defects, Dent, Pipelines, Integrity, Failure, Ultimate Tensile Strength.