Systems for removing blockages in subsea flowlines and equipment

Disclosed are various to blockage remediation systems for removing blockages, e.g., hydrate plugs, debris plugs, etc., from subsea flowlines and subsea equipment. In one illustrative embodiment, the system includes, among other things, an ROV (102) deployed into a body of water from a surface vessel (10) and a blockage remediation skid (104) that is operatively coupled to the ROV (102), wherein the skid (104) includes at least a skid fluid inlet (108A) and a skid fluid outlet (106A). The system also includes a returns downline (106) and a pressurized lift-gas supply downline (108) that extends into the body of from the vessel (10). The returns downline (106) is operatively coupled to the skid fluid outlet (106A), while the pressurized lift-gas supply downline (108) is adapted to be operatively and directly coupled to the blockage remediation skid (104) or operatively and directly coupled to the returns downline (106). The system also includes a remediation flow line (110) that is operatively coupled to the skid fluid inlet (110A) and a flowline (16) or an item of subsea equipment (12, 15 or 17).