A method and arrangement for well completion and intervention operations where a workover riser 4 projecting from a wellhead 6 and up to a vessel 2 is used, and where the upper portion of the workover riser 4 is designed to be displaced from an upper position to a lowered position favorable for rigging work, where at least the upper displaceable portion of the workover riser 4 essentially follows the heave motion of the vessel 2, whereupon the upper displaceable portion of the workover riser 4 is again raised to its upper position, the workover riser 4 being equipped with a telescoping connection 1.