Abstract: A downhole tool (1) is provided for plugging a hole in a wall of a downhole tubular (11). The tool has a tool housing (3) and a sting (7) arranged within the tool housing. The sting is moved in radially outward direction from the tool from a retracted position to an expanded position. A distal end of the sting plugs the hole in the wall of the downhole tubular. A spring blade (5) is arranged on the tool housing and in a trajectory of the sting. The sting (7) can extend from the tool housing through the spring blade (5), when the sting is in expanded position, whereby the distal end of the sting is exposed at the outward facing side of the spring blade. The spring blade is configured to be pressed elastically towards the tool housing by the wall of the downhole tubular pushing against an outward facing surface of the spring blade.

Abstract: A downhole seal is proposed which has a CO2 swellable elastomer which swells when in contact with CO2. The downhole seal can be set by installing a downhole seal comprising a CO2 swellable elastomer in a downhole location within a borehole, and exposing the downhole seal to contact with CO2 after installing, whereby the CO2 causes the downhole seal to swell.

Abstract: A downhole tool, with an elongate tool housing that extends around a central longitudinal tool axis, houses a sting, a press device, and a bending arm. The sting is movable in a radially outward direction. The press device acts on the sting, to force the sting in the radially outward direction upon relative movement of the press device, in longitudinal direction, with respect to the sting whereby the sting may extend outside the tool housing. The sting is mounted on a distal end of the bending arm. At its proximal end the bending arm is longitudinally secured stationary relative to the tool housing. The sting and the distal end of the bending arm are movable in unison in a longitudinal-radial plane from the central longitudinal tool axis. The downhole tool can be used to perforate a wall of a downhole tubular arranged within a borehole in the Earth.

Abstract: A downhole tool, with an elongate tool housing that extends around a central longitudinal tool axis, houses a sting, a press device, and a bending arm. The sting is movable in a radially outward direction. The press device acts on the sting, to force the sting in the radially outward direction upon relative movement of the press device, in longitudinal direction, with respect to the sting whereby the sting may extend outside the tool housing. The sting is mounted on a distal end of the bending arm. At its proximal end the bending arm is longitudinally secured stationary relative to the tool housing. The sting and the distal end of the bending arm are movable in unison in a longitudinal-radial plane from the central longitudinal tool axis. The downhole tool can be used to perforate a wall of a downhole tubular arranged within a borehole in the Earth.

Abstract: A downhole tool (1) is provided for plugging a hole in a wall of a downhole tubular (11). The tool has a tool housing (3) and a sting (7) arranged within the tool housing. The sting is moved in radially outward direction from the tool from a retracted position to an expanded position. A distal end of the sting plugs the hole in the wall of the downhole tubular. A spring blade (5) is arranged on the tool housing and in a trajectory of the sting. The sting (7) can extend from the tool housing through the spring blade (5), when the sting is in expanded position, whereby the distal end of the sting is exposed at the outward facing side of the spring blade. The spring blade is configured to be pressed elastically towards the tool housing by the wall of the downhole tubular pushing against an outward facing surface of the spring blade.

Abstract: A downhole tool, which includes a tool housing having a longitudinal axis, is equipped with a sting for punching a hole in a casing wall and injecting a sealant through the hole. The tube has a fluid channel to establish fluid communication from within the tool housing to an exterior of the tool housing through the fluid channel. A press device acts on the sting to force the sting in a radially outward direction from the tool housing. A check valve is arranged in the fluid channel, which allows fluid communication in a direction from within the tool housing to an exterior of the tool housing and which blocks fluid flow in an opposite direction. In use, the sting can perforate a casing wall and the sealant can be injected into an annular space around the casing.

Abstract: A downhole tool, which includes a tool housing having a longitudinal axis, is equipped with a sting for punching a hole in a casing wall and injecting a sealant through the hole. The tube has a fluid channel to establish fluid communication from within the tool housing to an exterior of the tool housing through the fluid channel. A press device acts on the sting to force the sting in a radially outward direction from the tool housing. A check valve is arranged in the fluid channel, which allows fluid communication in a direction from within the tool housing to an exterior of the tool housing and which blocks fluid flow in an opposite direction. In use, the sting can perforate a casing wall and the sealant can be injected into an annular space around the casing.

Abstract: A downhole seal is proposed which has a CO2 swellable elastomer which swells when in contact with CO2. The downhole seal can be set by installing a downhole seal comprising a CO2 swellable elastomer in a downhole location within a borehole, and exposing the downhole seal to contact with CO2 after said installing, whereby the CO2 causes the downhole seal to swell.

Abstract: A downhole tool, which includes a tool housing having a longitudinal axis, is equipped with a sting for punching a hole in a casing wall and injecting a sealant though said hole. The tube has a fluid channel to establish fluid communication from within the tool housing to an exterior of the tool housing through the fluid channel. A press device acts on the sting to force the sting in a radially outward direction from the tool housing. A check valve is arranged in the fluid channel, which allows fluid communication in a direction from within the tool housing to an exterior of the tool housing and which blocks fluid flow in an opposite direction. In use, the sting can perforate a casing wall and the sealant can be injected into an annular space around the casing.

Abstract: Migration of formation solids in a wellbore is restrained by feeding a slurry, comprising water, a viscosifier, and a concentration of cement clinker particles, into the wellbore, and hydrating the clinker particles in the wellbore. The clinker particles are kept in suspension during the hydrating, and upon completion of the hydrating the hydrated clinker particles form a hardened cement consisting of a permeable structure of interconnected hydrated clinker particles. A layer of degradable lost circulation material (LCM) may be employed to separate the slurry with clinker particles from the formation surrounding the wellbore during hydrating of the clinker particles.

Abstract: A method for sealing cavities in or adjacent to a cured cement sheath (4) surrounding a well casing (3) of an underground wellbore comprises: —providing an expansion device (1) with edged expansion segments (2) that is configured to be moved with the expansion segments (2) in an unexpanded configuration up and down through the well casing (3); —moving the unexpanded expansion device (1) to a selected depth in the well casing (3); and —expanding the edged expansion segments (2) at the selected depth, thereby plastically expanding a selected casing section and pressing the expanded casing section into the surrounding cement sheath thereby sealing the cavities.

Abstract: Migration of formation solids in a wellbore is restrained by feeding a slurry, comprising water, a viscosifier, and a concentration of cement clinker particles, into the wellbore, and hydrating the clinker particles in the wellbore. The clinker particles are kept in suspension during the hydrating, and upon completion of the hydrating the hydrated clinker particles form a hardened cement consisting of a permeable structure of interconnected hydrated clinker particles. A layer of degradable lost circulation material (LCM) may be employed to separate the slurry with clinker particles from the formation surrounding the wellbore during hydrating of the clinker particles.

Abstract: A method for sealing cavities in or adjacent to a cured cement sheath (4) surrounding a well casing (3) of an underground wellbore comprises: —providing an expansion device (1) with edged expansion segments (2) that is configured to be moved with the expansion segments (2) in an unexpanded configuration up and down through the well casing (3); —moving the unexpanded expansion device (1) to a selected depth in the well casing (3); and —expanding the edged expansion segments (2) at the selected depth, thereby plastically expanding a selected casing section and pressing the expanded casing section into the surrounding cement sheath thereby sealing the cavities.

Abstract: Slugs of a cement slurry and of a resin composition are injected into an underground wellbore. The resin composition contains at least a curable resin, a filler, a swelling agent, a curing initiator, and a crosslinking retarding agent. The curing initiator activates the curing in response to temperature. The crosslinking retarding agent delays curing of the resin, to permit pumping the composition into the wellbore. After injection, the cement slurry and resin composition are allowed to cure, to create a stacked cement and cured resin column that provides a zonal isolation seal within the wellbore. The resin composition may suitably be an elastomer-forming composition. The cured resin may be swellable by allowing contact with a wellbore fluid.

Abstract: A velocity string for increasing fluid velocity in a production tubing (1) of a wet natural gas production well is configured downhole by:—inserting components (5) for configuring an annular liner (4) into the production tubing (1); and—clustering the components together in an annular space (9) adjacent to an inner surface of the production tubing (1) to configure the annular liner (4) in a cost effective manner without requiring killing the well with a high density liquid, expensive hoisting and/or other workover equipment and materials required to install conventional corrosion resistant steel velocity strings.

Abstract: The invention concerns a method of applying a coating in a liquid state to wellbore tubing, such as threaded connector parts or casing sections, before running the tubing downhole. The coating only cures while running downhole. The coating is an elastic curable coating composition, comprising a curable elastic thermosetting resin, a curing agent and a water-absorbing expansion agent. During make-up of a connector, the liquid coating composition acts as lubricant. When cured, the coating will swell when contacted with a wellbore fluid to ensure leak-tightness.

Abstract: The invention concerns a method of applying a coating in a liquid state to wellbore tubing, such as threaded connector parts or casing sections, before running the tubing downhole. The coating only cures while running downhole. The coating is an elastic curable coating composition, comprising a curable elastic thermosetting resin, a curing agent and a water-absorbing expansion agent. During make-up of a connector, the liquid coating composition acts as lubricant. When cured, the coating will swell when contacted with a wellbore fluid to ensure leak-tightness.

Abstract: The invention provides a method and system for sealing an annulus enclosing a tubular element in a wellbore. The method comprises the steps of: i) introducing a first drilling fluid in the wellbore; ii) drilling an open hole section of the wellbore using a drilling tool suspended at the end of a tool string; iii) pumping a second drilling fluid comprising particles into the wellbore; iv) filtering the particles out of the second drilling fluid near a downhole end of the tubular element; v) extending the tubular element into the open hole section of the wellbore while directing at least part of the filtered particles to an annulus between the tubular element and a wellbore wall. Steps i) to v) may be repeated as often as required.

Abstract: A method of providing an annular seal around a tubular in a wellbore penetrating a subsurface formation, the method comprising providing a tubular in the wellbore, wherein an annular space (18) is formed around the tubular; providing an annular gravel pack in the annular space; wherein the method further comprises arranging a band (9a, 9b, 9c, 9d) of gel-forming material around the tubular before providing the annular gravel pack, wherein the gel-forming material is swellable in a selected fluid, and wherein the annular seal is formed by contacting the band of gel-forming material with the selected fluid; and a wellbore system comprising a gravel-packed tubular in a wellbore, wherein the tubular is provided with a band of gel-forming material in a layer around the tubular, the band being surrounded by gravel (15), and wherein the gel-forming material is swellable in a selected fluid.

Abstract: A method is disclosed of creating an annular seal around a tubular element for use in a wellbore. The method comprises providing at least one seal layer of a flexible sealing material susceptible to swelling upon contact with a selected fluid, the seal layer having a first edge and a second edge, and helically winding each seal layer around the tubular element so that the first and second edges extend opposite each other along the tubular element and so that the first and second edges seal relative to each other upon swelling of the flexible sealing material. The tubular element is lowered into the wellbore, and the selected fluid is allowed to contact each seal layer so as to induce swelling of the flexible sealing material whereby the first and second edges seal relative to each other.