Method for controlling buckling in deepwater pipeline with inclined sleepers

A method for controlling buckling in subsea pipelines, comprising the steps of:

• providing a subsea pipeline on a seafloor, the subsea pipeline having an initial as-laid position;
• identifying a plurality of spaced-apart sections of the subsea pipeline suitable for controlled lateral buckling;
• installing a set of inclined sleepers at each spaced-apart section in an orientation that is perpendicular to the initial as-laid position, each of the inclined sleepers in the set of inclined sleepers installed in a spaced-apart relationship;
• wherein the set of inclined sleepers has at least three inclined sleepers comprising an upstream inclined sleeper, a central inclined sleeper, and a downstream inclined sleeper, and a length of each inclined sleeper is selected to accommodate a projected lateral deformation relative to the initial as-laid position;
• wherein the length of the central inclined sleeper is longer than the length of the upstream and downstream inclined sleepers, corresponding to a shape of the projected lateral deformation relative to the initial as-laid position;
• whereby any buckling caused by thermal expansion of the subsea pipeline is distributed to two or more of the spaced-apart sections, causing the two or more spaced-apart sections to deflect laterally along the inclined sleepers, outwardly from the initial as-laid position.