Subsea control pod deployment and retrieval systems and methods

A system for replacing a first control pod coupled to a subsea BOP stack with a second control pod, the system comprising:

• a lifting device coupled to a surface vessel;
• a control pod exchange device suspended from the lifting device and configured to be raised and lowered subsea by the lifting device, wherein the control pod exchange device comprises:
• a housing;
• a plurality of laterally adjacent bays disposed within the housing, wherein each bay is sized to accommodate the first control pod or the second control pod;
• and
• a control pod transfer assembly moveably disposed in the housing, wherein the control pod transfer assembly is configured to move the first control pod and the second control pod within the housing between at least two of the plurality of laterally adjacent bays;
• a BOP stack connection assembly coupled to the control pod exchange device, wherein the BOP stack connection assembly is configured to couple the control pod exchange device to the BOP stack.

A method for replacing a first control pod of a BOP stack, the method comprising:

• (a) loading a second control pod onto a control pod exchange device;
• (b) lowering the control pod exchange device subsea after (a) with a lifting device mounted to a surface vessel, wherein the control pod exchange device is suspended from the lifting device with a first rope or a pipe string;
• (c) coupling a BOP stack connector to the BOP stack after (b), wherein a second rope has a first end coupled to the control pod exchange device and a second end coupled to the BOP stack connector;
• and
• (d) lowering the first rope or the pipe string to allow the control pod exchange device to be lowered along the second rope, and relative to the first rope or the pipe string, to the BOP stack connector after (c).