Abstract: For the sealing performances of three premium connections with -15°, -5° and right-angle shoulders separately, simulation calculations are conducted under the conditions of making-up, making-up+tensile loading, and making-up+compressive loading.The analysis of the simulation calculations reveals the facts as follows.Under the making-up condition, any change of the shoulder angle remarkably affects the sealing performance of sealing surface of the premium connection, but only slightly affects the shoulder's auxiliary sealing performance.Under the making-up+tensile loading condition, any change of the shoulder angle just slightly affects the contact stress at the sealing surface of the connection, whereas the shoulder's auxiliary sealing performance fails along with disengagement and opening between the pipe end and the shoulder.And under the making-up+compressive loading condition, the 15° shoulder connection shows the best sealing performance on the sealing surface, and likely, the compressive loading produces little effect on the shoulder's auxiliary sealing surface.