An example system includes a moveable platform having an uphole end and a downhole end. The platform includes a drive arrangement for moving the platform in one or more directions along an interior wall of a casing string in a wellbore. The platform includes scraping arrangement for removing debris from the interior wall of the casing string. The platform includes a debris catching arrangement downhole of the scraping arrangement for collecting some or all of the debris removed. The platform may include a coating arrangement to deliver and apply a substance to at least a part of the wall of the casing string. The coating arrangement may include a reservoir holding one or more liquid substances and a valve to regulate flow of the one or more liquid substances. The liquid substance may include epoxy resin.

A first expandable tubular is longitudinally extendable from a housing. The first expandable tubular is expandable to a diameter equal to an internal surface of a wellbore. A first expander is configured to expand the expandable tubular. A second expandable tubular is longitudinally extendable from the housing. The second expandable tubular is configured to expand to a diameter equal to an internal surface of the wellbore. The second expandable tubular is downhole of the first expandable tubular. A second expander is configured to expand the second expandable tubular. The second expander is downhole of the first expander. A sensor is downhole of the second expander. The sensor is configured to detect a presence of a wellbore obstruction proximal to the tool.

A cement wiper plug for deployment in casing with an inner radius has a central axis, a leading end, and a trailing end opposite the leading end. The wiper plug includes an elongate body. In addition, the wiper plug includes a first plurality of axially adjacent annular fins mounted to the body. Each fin extends radially outward from the body and each fin extends circumferentially about the body. The first plurality of fins includes a first fin and a second fin axially adjacent the first fin. The second fin is axially positioned between the first fin and the trailing end. The first fin and the second fin are configured to contact each other in the casing. The second fin is configured to bias the first fin radially outward and axially forward toward the leading end.

A cement wiper plug for deployment in casing with an inner radius has a central axis, a leading end, and a trailing end opposite the leading end. The wiper plug includes an elongate body. In addition, the wiper plug includes a first plurality of axially adjacent annular fins mounted to the body. Each fin extends radially outward from the body and each fin extends circumferentially about the body. The first plurality of fins includes a first fin and a second fin axially adjacent the first fin. The second fin is axially positioned between the first fin and the trailing end. The first fin and the second fin are configured to contact each other in the casing. The second fin is configured to bias the first fin radially outward and axially forward toward the leading end.

A procedure and apparatus for cementing and cleaning a reservoir liner 3 comprises installing a reservoir liner using a drill string 4 which extends only as far as the distal end of a cased part 2 of the well, then, using the drill string, displacing cement into the reservoir liner using completion fluid whereby, when the cement is in place in the annulus around the reservoir liner, the reservoir liner is already clean and filled with completion fluid. A ball valve 6 at the top of the reservoir liner 3 is then closed before the cased part 2 of the wellbore is cleaned, to avoid debris entering the reservoir liner.

A procedure and apparatus for cementing and cleaning a reservoir liner 3 comprises installing a reservoir liner using a drill string 4 which extends only as far as the distal end of a cased part 2 of the well, then, using the drill string, displacing cement into the reservoir liner using completion fluid whereby, when the cement is in place in the annulus around the reservoir liner, the reservoir liner is already clean and filled with completion fluid. A ball valve 6 at the top of the reservoir liner 3 is then closed before the cased part 2 of the wellbore is cleaned, to avoid debris entering the reservoir liner.

The invention relates to a collecting device for collecting debris of deposits while said deposits are being removed from a wellbore wall or an equipment arranged in a wellbore of a subterranean formation in order to improve the recovery of formation fluids and/or gases, said collecting device being configured for being attached to a cleaning device, said cleaning device being configured for removing deposits from a wellbore wall or an equipment arranged in a wellbore. The collecting device comprises a deflector, configured for deflecting falling debris of deposits while said deposits are being removed from said wellbore wall or said equipment, and a debris storing module, connected to said deflector for collecting and storing debris deflected by said deflector.

The invention relates to an electrical discharge generating device for cleaning an equipment arranged in a wellbore of a subterranean formation in order to improve the recovery of formation fluids and/or gases, said electrical discharge generating device comprising a discharge unit for generating at least one electrical discharge that propagates at least one shock wave for cleaning from said equipment, wherein said electrical discharge generating device further comprises a retaining module configured for retaining a volume of liquid in order to immerse the discharge unit.

The invention relates to an electrical discharge generating device for cleaning an equipment arranged in a wellbore of a subterranean formation in order to improve the recovery of formation fluids and/or gases, said electrical discharge generating device comprising a discharge unit for generating at least one electrical discharge that propagates at least one shock wave for cleaning from said equipment, wherein said electrical discharge generating device further comprises a retaining module configured for retaining a volume of liquid in order to immerse the discharge unit.

A procedure and apparatus for cementing and cleaning a reservoir liner 3 comprises installing a reservoir liner using a drill string 4 which extends only as far as the distal end of a cased part 2 of the well, then, using the drill string, displacing cement into the reservoir liner using completion fluid whereby, when the cement is in place in the annulus around the reservoir liner, the reservoir liner is already clean and filled with completion fluid. A ball valve 6 at the top of the reservoir liner 3 is then closed before the cased part 2 of the wellbore is cleaned, to avoid debris entering the reservoir liner.