The present invention relates to an abandonment plug for plug and abandonment of a well, said abandonment plug comprising a first end part being closable or closed, a second end part being tubular and having a groove in an inner face, an expandable metal sleeve arranged between the end parts, the end parts being more rigid than the expandable metal sleeve, and an unit releasably connected to the second tubular end part, the unit comprising at least one radially projectable fastening element, a unit sleeve, and a piston movable in the unit sleeve for, in a first position, forcing the radially projectable fastening element and, in a second position, being offset in relation to the radially projectable fastening element, allowing the radially projectable fastening element to move radially inwards. Furthermore, the present invention relates to a plug and abandonment system comprising the abandonment plug according to the present invention.

A non-metallic tubular defines a central flow passage. Actuable rollers are actuable between an extended position and a retracted position. The actuable rollers are pivotally attached to the non-metallic tubular. The actuable rollers centralize the non-metallic tubular when in the extended position. The actuable rollers extend between the non-metallic tubular to an inner surface of the wellbore when in the extended position. A connector is attached to an uphole end of the non-metallic tubular. The connector is configured to attach to a downhole end of a work string.

In described examples, there are systems and methods for deployment in proximity to an abandoned well. The systems and methods may allow use of data collected from an abandoned well, in which a sensor is positioned in the open hole section, or a well having a discontinuous metallic well structure. In some examples, there is described a communication system that is configured to be deployed in an abandoned well having a discontinuous metallic well structure that may be severed below a ground region.

A method of plugging a hydrocarbon well includes deploying a downhole tool to remove at least a portion of a casing at a section of well to be plugged. Then a plugging material is put downhole onto a blocking device to fill an area to be plugged. An exothermic fluid is added, wherein activation of the exothermic material liquefies the plugging material. Allowing the plugging material and the exothermic fluid to solidify form a cast-in-place plug that fills the section of well to be plugged.

A frac plug system for use in a wellbore, including a frac plug; and a plug member configured to set the frac plug in the wellbore and to control a flow of fluid through the frac plug once the frac plug is set in the wellbore. A method of controlling a flow of fluid within a wellbore, including conveying a frac plug system in the wellbore, the frac plug system including a frac plug and a plug member; setting the frac plug in the wellbore using the plug member; and control the flow of fluid through the frac plug using the plug member once the frac plug is set in the wellbore.

A plug for plugging wells, and in particular oil and gas wells, is provided. The plug has a plug body formed from an outer metal tube of a reduced thickness. The plug also has reinforcement means, attached to an inner surface of the outer tube, that give the plug a cross-sectional structural strength that is at least equivalent to that of a thicker metal tube. The plug has a central heater receiving void located along the axis of the plug to enable a plug deployment heater to be received therein. Also provided is a plug assembly with a variable cross-sectional area in a plane perpendicular to the plane in which the assembly is deployed during the plugging of underground conduits.

A method of sealing an annulus between first and second bore-lining tubulars comprises providing a first bore-lining tubular having a first volume of alloy thereon and running the first bore-lining tubular into a bore provided with a second bore-lining tubular. The alloy is fluidised and then allowed to solidify in an annulus between the bore-lining tubulars and bond the tubulars together. The alloy may be fluidised in the presence of flux.

A method of plugging a hydrocarbon well includes deploying a downhole tool to remove at least a portion of a casing at a section of well to be plugged. Then a plugging material is put downhole onto a blocking device to fill an area to be plugged. An exothermic fluid is added, wherein activation of the exothermic material liquefies the plugging material. Allowing the plugging material and the exothermic fluid to solidify form a cast-in-place plug that fills the section of well to be plugged.

The present invention provides an actuation member for traveling down a borehole of a casing to engage with one or more geometrical profile locations provided inside the casing, and a system for controllably exposing selected locations along the wellbore to a pressurized fluid. The actuation member comprises a generally cylindrical hollow body extending between an uphole end and a downhole end, and a plug seat configured to receive a plug for blocking the borehole. The actuation member has two edge portions separate and movable relative to one another to facilitate resilient deformation of the hollow body, wherein the deformation causes a reduction of cross-sectional area of the hollow body. An outer surface of the hollow body comprises one or more protrusions and/or grooves configured to matingly engage with the one or more geometric profile locations in the casing.

A power generator system includes one or more heat transfer members configured to contact: a heat source in a hazardous waste repository of a directional drillhole that stores nuclear waste in one or more nuclear waste canisters, and a heat sink in the hazardous waste repository; and one or more thermoelectric generators thermally coupled to the one or more heat transfer members and configured to generate electric power based on a temperature difference between the heat source and the heat sink.