Floating Production Storage Offloading (FPSO) Vessels are widely used in offshore oil and gas industry. In offshore Atlantic Canada, mooring piles driven in the seabed, in water depths ranging from 80 to 200 m, are used to moor these FPSOs. These mooring piles are subjected to oblique pull forces. In this paper, a 3D finite element method has been used to study the behaviour of steel pipe piles in saturated sand under mooring forces. The main objective of the present study is to check the validity of the available theoretical models in the literature. It has been found that most of the previous theoretical models should be modified to consider the prototype behaviour.