Abstract: Methods for more reliably cementing and remediating oil and gas wells by plastically expanding the diameter of the wellbore casing at select locations along the wellbore to control fluid flow in the micro-annular leak paths formed in the casing annulus between the casing and cement sheath, or between the casing and wellbore. Such methods do not require pre-placement of casing packers or prediction of potential leak points of the casing annulus. In cementing operations, casing expansion can be performed at strategic locations along the wellbore to eliminate annular leak paths that permit detrimental flow, direct the flow of cement to the desired portions of the wellbore, and prevent the flow of cement to oil producing formations. In instances of inter-zonal communication between subterranean formations, casing expansion can be performed at location(s) between the formations to mitigate or prevent inter-zonal communication via annular leak paths in the casing annulus.

Abstract: A tool is provided for expanding the casing at one or more locations for arresting surface casing vent flow in an abandoned well. A setting tool is run into the bore having an expansion element supported thereon. The setting tool imparts a large axial force to radially expand the expansion element for plastically deforming the casing. A single use, pleated ring crushable expansion element can be actuated and left downhole. The pleated ring tool can be pre-charged with a highly viscous fluid, semi solid for transport, but plastic under load. A multi-use expansion element can be actuated, released, moved and actuated again at successive locations.

Abstract: A tool is provided for expanding the casing at one or more locations for arresting surface casing vent flow in an abandoned well. A setting tool is run into the bore having an expansion element supported thereon. The setting tool imparts a large axial force to radially expand the expansion element for plastically deforming the casing. A single use, pleated ring crushable expansion element can be actuated and left downhole. The pleated ring tool can be pre-charged with a highly viscous fluid, semi solid for transport, but plastic under load. A multi-use expansion element can be actuated, released, moved and actuated again at successive locations.

Abstract: A tool is provided for use in closing and sealing the cased bore of a well to be abandoned. The tool is run into the bore, the tool having a stack of pleated rings slidably mounted on a tubular mandrel. The tool is engaged with the casing and a charge of hot asphaltic sealant is discharged from a conveyed container to flood the stack and tool annulus. The stack is compressed axially to partly flatten and radially expand the rings to frictionally engage the surrounding casing, the rings and sealant sealing the bore. Further, the rings can expand the heated casing for sealing casing/cement interfaces. The sealant solidifies and creates an impermeable mass sealing against surfaces of the mandrel, stack and casing.