Subsea flowline blockage remediation using external heating device

An external heating assembly usable to heat a subsea flowline subsea to remediate blockages, comprising:

• a. a first end;
• b. a second end disposed distally from the first end;
• c. a predetermined set of heaters adapted to be disposed proximately and externally to, and longitudinally along, an exposed exterior surface of a subsea flowline between the first end and the second end;
• d. a conductive layer disposed between the first end and the second end and adapted to be disposed about the exposed portion of an 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 conductive layer configured to uniformly distribute heat over the exterior of the subsea flowline;
• e. an insulating layer disposed between the first end and the second end about the conductive layer and configured to be disposed the conductive layer away from the subsea flowline, the insulating layer adapted to shield the subsea flowline, the predetermined set of heaters, and the 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;
• f. a first clamp disposed at the first end;
• g. 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
• h. 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.