Subsea flowline blockage remediation using external heating device

A method, comprising:

• a) disposing an external heating assembly, usable to heat a subsea flowline to remediate a blockage in the subsea flowline, proximate the subsea flowline, the external heating assembly comprising:
• i) a first end;
• ii) a second end disposed distally from the first end;
• iii) a predetermined set of heaters adapted to be disposed proximate and externally to, and longitudinally along, an exposed exterior surface of the subsea flowline between the first end and the second end, the predetermined set of heaters comprising a predetermined set of heating cables;
• iv) a heat conductive layer disposed between the first end and the second end and adapted to be disposed about the exposed portion of the exterior surface of the subsea flowline and about a predetermined portion of the predetermined set of heaters so as to not preclude access to the exposed portion of the exterior surface of the subsea flowline by the predetermined set of heaters, the heat conductive layer configured to uniformly distribute heat over the exterior of the subsea flowline;
• v) an insulating layer disposed about the heat conductive layer between the first end and the second end and configured to be disposed away from the heat conductive layer and away from the subsea flowline, the insulating layer adapted to shield the subsea flowline, the predetermined set of heaters, and the heat conductive layer from ambient seawater temperature, the insulating layer comprising an insulating blanket comprising an insulating material which can withstand a predetermined set of hydrostatic forces;
• vi) an anchor comprising a first clamp disposed at the first end and a second clamp disposed at the second end, the first clamp and the second clamp adapted to provide a clamping force sufficient to secure the external heating assembly to the subsea flowline;
• and
• vii) a strength member terminated at the first clamp and the second clamp, the strength member adapted to provide structural strength for lifting the external heating assembly;
• and
• b) providing electrical power to the predetermined set of heating cables sufficient to energize the predetermined set of heaters and cause the predetermined set of heaters to provide heat sufficient to remediate the blockage in the subsea flowline.