Methods for preserving zonal isolation within a subterranean formation

A method for effecting at least partial interference of a fluid passage extending between a subterranean formation and a casing disposed within an open-hole or cased-hole completed wellbore penetrating the subterranean formation, comprising:

• deploying a tool within the wellbore after zonal isolation material disposed between the casing and the subterranean formation has set;
• in response to detecting of the fluid passage, radially expanding the tool to effect an operative displacement of a section of the casing to a displaced position, wherein, upon the section of the casing becoming displaced, the zonal isolation material becomes disposed opposite to the subterranean formation and effects at least partial interference of the fluid passage extending between the casing and the subterranean formation;
• and
• effecting opposition to an elastic contraction of the displaced casing section for mitigating reversion of the displaced casing section towards its original position prior to the operative displacement,
• wherein the tool remains within the section of the casing to maintain the opposition to the elastic contraction of the displaced casing section.

A method for effecting at least partial interference of a fluid passage extending between a casing and a subterranean formation, wherein the casing is disposed within a wellbore that is penetrating a subterranean formation, and wherein cement is disposed between the casing and the subterranean formation, comprising:

• deploying a tool including a split ring within the wellbore;
• expanding the split ring against a casing section to effect an operative displacement of the casing section to a displaced position, wherein, upon the casing section becoming displaced to the displaced position, the cement becomes disposed opposite to a subterranean formation portion that is relatively impermeable and effects the at least partial interference of the fluid passage;
• and
• effecting retention of the casing section in the displaced position, or in substantially the displaced position, with the expanded split ring.

A method for effecting at least partial interference of a fluid passage extending between a subterranean formation and a casing disposed within an open-hole or cased-hole completed wellbore penetrating the subterranean formation, comprising:

• after cement disposed between the casing and the subterranean formation has set, deploying within the wellbore a tool including a sleeve and a mandrel, wherein the sleeve is configured to be radially expanded in response to relative movement between the mandrel and the sleeve along their respective tapered surfaces;
• and
• in response to detecting of the fluid passage, actuating relative movement between the mandrel and the sleeve along their respective tapered surfaces such that the sleeve is radially expanded and the radially expanded sleeve is pressed against the casing section such that an operative displacement of the casing section is effected, wherein, upon the casing section becoming displaced to the displaced position, the cement becomes disposed between the casing and the subterranean formation and effects at least partial interference of the fluid passage,
• wherein the tool remains within the section of the casing to maintain the operative displacement of the casing section to the displaced position.

A method for occluding a gap between a casing of an open-hole or cased-hole completed wellbore and a formation, the method comprising:

• after zonal isolation material disposed between the casing and the formation has set, identifying the presence of the gap between the casing's external surface and the formation;
• deploying an expansion tool within the casing;
• and
• radially expanding the expansion tool to apply an outward force against the casing with the expansion tool, thereby expanding and operatively displacing the casing radially outwards to a displaced position, wherein, upon the casing becoming displaced, the zonal isolation material between the casing and the formation becomes disposed opposite to the formation and effects occlusion of the gap,
• wherein the expansion tool remains within the section of the casing to maintain the operative and radially outward displacement of the casing section to the displaced position.

A method for restoring zonal isolation in a cased and cemented portion of a thermally operated and open-hole or cased-hole completed well in a formation, wherein zonal isolation material is disposed between the casing and the formation, the method comprising:

• detecting the presence of a gap extending between the casing and the formation after the zonal isolation material has set;
• deploying an expansion tool within a section of the casing;
• and
• radially expanding the expansion tool to effect an operative and radially outward displacement of the casing section to a displaced position, wherein, upon the casing section being displaced, the zonal isolation material becomes disposed opposite to the formation and effects occlusion of the gap,
• wherein the expansion tool remains within the section of the casing to maintain the operative and radially outward displacement of the casing section to the displaced position.