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 subsurface wellbore wiper deployment system includes a plug having an elongated body with an exterior surface; one or more exposed wipers extending away from the exterior surface; and one or more hidden wipers secured to the exterior surface and positioned underneath a removable sleeve; and a landing collar having a landing seat extending into an interior of the landing collar; the removable sleeve is to engage with the landing seat upon deployment of the plug; and the landing collar removes the removable sleeve to expose the one or more hidden wipers.

A pressure control device for sealing a conduit comprises a seal element comprising an elastomer, the seal element defining a seal element external surface portion, the seal element external surface portion defining an external perimeter. The external perimeter is adapted to increase as an environmental temperature increases, such that, in use, an increase in the environmental temperature can move the seal element external surface portion into engagement with the conduit or, once engaged with the conduit or if already engaged with the conduit, can create an improved seal with the conduit.

A pressure control device for sealing a conduit comprises a seal element comprising an elastomer, the seal element defining a seal element external surface portion, the seal element external surface portion defining an external perimeter. The external perimeter is adapted to increase as an environmental temperature increases, such that, in use, an increase in the environmental temperature can move the seal element external surface portion into engagement with the conduit or, once engaged with the conduit or if already engaged with the conduit, can create an improved seal with the conduit.

A sand removal system configured to remove sand from a casing installed within a producing wellbore. The system utilizes a bottom hole assembly comprising a check valve sub and at least one sand removal tool. A swab cup installed within a vertical section the casing is used to create a pressure differential around the bottom hole assembly, causing fluid and sand to flow at a high velocity into the sand removal tool. The sand is caused to flow upstream where is later removed from the wellbore.

A sand removal system configured to remove sand from a casing installed within a producing wellbore. The system utilizes a bottom hole assembly comprising a check valve sub and at least one sand removal tool. A swab cup installed within a vertical section the casing is used to create a pressure differential around the bottom hole assembly, causing fluid and sand to flow at a high velocity into the sand removal tool. The sand is caused to flow upstream where is later removed from the wellbore.

An assist device for propelling a tool through a conduit, the assist device including an upstream housing having a first port; a downstream housing movably attached to the upstream housing and the downstream housing having a second port; and a swab element attached to the downstream housing. The first port is closed when there is no gap between the upstream housing and the downstream housing, and the first port is open when there is a gap between the upstream housing and the downstream housing.

An assist device for propelling a tool through a conduit, the assist device including an upstream housing having a first port; a downstream housing movably attached to the upstream housing and the downstream housing having a second port; and a swab element attached to the downstream housing. The first port is closed when there is no gap between the upstream housing and the downstream housing, and the first port is open when there is a gap between the upstream housing and the downstream housing.

A casing string is augmented with one or more variable flow resistance devices or vibrating tools to facilitate advancement of the casing and distribution of the cement in the annulus once the casing is properly positioned. Vibrating tools in the form of plugs can be pumped down and landed inside the casing string. The method includes vibrating the casing string while advancing the casing down the wellbore or while the cement is pumped into the annulus, or both. After the cementing operation is completed, the devices may be drilled out or retrieved with fishing tools to reopen the casing string for further operations. One or more wipers may be provided on the plugs, but the section housing the flow path may be free of wipers to allow the size and flow capacity of the flow path to be optimized.

A casing string is augmented with one or more variable flow resistance devices or vibrating tools to facilitate advancement of the casing and distribution of the cement in the annulus once the casing is properly positioned. Vibrating tools in the form of plugs can be pumped down and landed inside the casing string. The method includes vibrating the casing string while advancing the casing down the wellbore or while the cement is pumped into the annulus, or both. After the cementing operation is completed, the devices may be drilled out or retrieved with fishing tools to reopen the casing string for further operations. One or more wipers may be provided on the plugs, but the section housing the flow path may be free of wipers to allow the size and flow capacity of the flow path to be optimized.