Abstract: A downhole tool, for removing sections of metal tubing, said downhole tool comprising at least one conductive element being arranged to corrode a section of metal tubing using an electrolytic process, said conductive element being made of electric conductive material, an apparatus to establish a connection to the metal tubing, and a source of electrical power.

Abstract: A method of plugging a well extending into a formation to facilitate temporary or permanent abandonment of the well. The method comprises conveying a plug placement and verification tool (PPVT) through the well, to a plug formation location, the PPVT comprising a stinger for delivering a plugging material into the well, an expandable packer disposed at one end of the stinger and a pressure sensor disposed below the expandable packer, and operating the expandable packer to form a seal in the well above the pressure sensor. The method further comprises delivering a plugging material from the stinger into a region of the well above the expandable packer, thereby forming a plug in the well, and thereafter creating a pressure change above the plug and verifying the integrity of the plug using the pressure sensor.

Abstract: A method of plugging a well extending into a formation to facilitate temporary or permanent abandonment of the well. The method comprises conveying a plug placement and verification tool (PPVT) through the well, to a plug formation location, the PPVT comprising a stinger for delivering a plugging material into the well, an expandable packer disposed at one end of the stinger and a pressure sensor disposed below the expandable packer, and operating the expandable packer to form a seal in the well above the pressure sensor. The method further comprises delivering a plugging material from the stinger into a region of the well above the expandable packer, thereby forming a plug in the well, and thereafter creating a pressure change above the plug and verifying the integrity of the plug using the pressure sensor.

Abstract: A method of plugging a well extending into a formation to facilitate temporary or permanent abandonment of the well. The method includes conveying a plug placement and verification tool (PPVT) through the well, to a plug formation location, the PPVT including a stinger for delivering a plugging material into the well, an expandable packer disposed at one end of the stinger and a pressure sensor disposed below the expandable packer, and operating the expandable packer to form a seal in the well above the pressure sensor. The method further includes delivering a plugging material from the stinger into a region of the well above the expandable packer, thereby forming a plug in the well, and thereafter creating a pressure change above the plug and verifying the integrity of the plug using the pressure sensor.

Abstract: A method of plugging a well in a plug and abandonment procedure includes providing a tubing in a wellbore, in a location for a well plug, the tubing is provided with an internal cable section placed inside of the tubing, and forming a plug in the well in said location for the well plug across the width of the tubing and a surrounding wellbore annulus to create a permanent barrier without pulling the tubing from the wellbore. The step of forming the plug includes substantially removing the internal cable section inside the tubing and forming a fluid-tight seal in the tubing where the internal cable section has been removed, for separating, on either side of the seal, first and second fluid volumes of the tubing.

Abstract: A method of sealing a well comprises creating one or more openings in a tubing installed in a wellbore, in a location for a well seal; using a wireline to locate a stinger in that location; setting the stinger in that location; and forming a seal in the well in that location, by injecting sealant through said stinger.

Abstract: There is provided a method for removing iron-containing casing from a well bore comprising providing a cathode in said well bore, wherein said cathode is connected to the negative pole of a power source; connecting said iron-containing casing to the positive pole of said power source; injecting an electrolyte into said well bore, wherein said electrolyte contacts said iron-containing casing and said cathode; applying a current so that the iron in said iron-containing casing is oxidised to iron cations; allowing said iron cations to dissolve in said electrolyte; and removing said electrolyte from said well bore. Also provided are a system for removing iron-containing casing from a well bore, a method for monitoring the removal of an iron-containing casing from a well bore and a method for plugging and abandoning a well.

Abstract: A method of plugging a well extending into a formation to facilitate temporary or permanent abandonment of the well. The method comprises conveying in one trip, a plug assembly and one or more explosive charges through the well together with a structure for providing wet sealant. The plug assembly comprises a foundation plug for supporting the wet sealant. The plug assembly is set beneath a plug formation location, prior to providing the wet sealant. The method also comprises providing the wet sealant to the plug formation location via the structure, so as to submerge the one or more explosive charges in the wet sealant, and then detonating the one or more explosive charges in the wet sealant at the plug formation location to cut through a tubular or tubulars of the well and into the formation.

Abstract: A method of plugging a well extending into a formation to facilitate temporary or permanent abandonment of the well. The method includes conveying a plug placement and verification tool (PPVT) through the well, to a plug formation location, the PPVT including a stinger for delivering a plugging material into the well, an expandable packer disposed at one end of the stinger and a pressure sensor disposed below the expandable packer, and operating the expandable packer to form a seal in the well above the pressure sensor. The method further includes delivering a plugging material from the stinger into a region of the well above the expandable packer, thereby forming a plug in the well, and thereafter creating a pressure change above the plug and verifying the integrity of the plug using the pressure sensor.

Abstract: A method of sealing a well comprises creating one or more openings in a tubing installed in a wellbore, in a location for a well seal; using a wireline to locate a stinger in that location; setting the stinger in that location; and forming a seal in the well in that location, by injecting sealant through said stinger.

Abstract: A method of plugging a well in a plug and abandonment procedure includes providing a tubing in a wellbore, in a location for a well plug, the tubing is provided with an internal cable section placed inside of the tubing, and forming a plug in the well in said location for the well plug across the width of the tubing and a surrounding wellbore annulus to create a permanent barrier without pulling the tubing from the wellbore. The step of forming the plug includes substantially removing the internal cable section inside the tubing and forming a fluid-tight seal in the tubing where the internal cable section has been removed, for separating, on either side of the seal, first and second fluid volumes of the tubing.

Abstract: A method of plugging a well includes providing a tubing in a wellbore, wherein in a location for a well plug, the tubing is provided with an internal cable section placed inside of the tubing and/or an external cable section placed outside of the tubing, the external cable section including a fluid-tight cable suitable for forming a sealing part of the well plug, and forming a plug in the well in the location for the well plug without pulling the tubing from the wellbore.

Abstract: A method of sealing a well comprises creating one or more openings in a tubing installed in a wellbore, in a location for a well seal; using a wireline to locate a stinger in that location; setting the stinger in that location; and forming a seal in the well in that location, by injecting sealant through said stinger.

Abstract: A method of plugging a well extending into a formation to facilitate temporary or permanent abandonment of the well. The method comprises conveying in one trip, a plug assembly and one or more explosive charges through the well together with a structure for providing wet sealant. The plug assembly comprises a foundation plug for supporting the wet sealant. The plug assembly is set beneath a plug formation location, prior to providing the wet sealant. The method also comprises providing the wet sealant to the plug formation location via the structure, so as to submerge the one or more explosive charges in the wet sealant, and then detonating the one or more explosive charges in the wet sealant at the plug formation location to cut through a tubular or tubulars of the well and into the formation.

Abstract: A method of centralizing a tubing in a wellbore includes providing one or more expandable elements between the tubing and a surrounding casing located in a wellbore and expanding the expandable elements against the casing so as to cause the tubing to become centered within the casing. Alternatively, one or more portions of a tubing are expanded against a surrounding casing located in a wellbore so as to cause the tubing to become centered within the casing.

Abstract: There is provided a method for removing iron-containing casing from a well bore comprising providing a cathode in said well bore, wherein said cathode is connected to the negative pole of a power source; connecting said iron-containing casing to the positive pole of said power source; injecting an electrolyte into said well bore, wherein said electrolyte contacts said iron-containing casing and said cathode; applying a current so that the iron in said iron-containing casing is oxidised to iron cations; allowing said iron cations to dissolve in said electrolyte; and removing said electrolyte from said well bore. Also provided are a system for removing iron-containing casing from a well bore, a method for monitoring the removal of an iron-containing casing from a well bore and a method for plugging and abandoning a well.

Abstract: A method and apparatus for determining multiphase flow characteristics inside production equipment containing at least two fluids. A pulse of heat from a heat source adjacent to the production equipment is provided, and a thermal response to the pulse is measured at each of a plurality of temperature sensors located adjacent to the production equipment. The thermal response measurement includes a time constant obtained from a measured decline in the temperature after the pulse of heat has been provided. The measured thermal responses are used to determine parameters of a fluid contained in the production equipment in proximity to each of the temperature sensors. The determined fluid parameters are in turn used to determine multiphase flow characteristics.

Abstract: A method of centralising tubing (10) in a wellbore comprises either providing one or more expandable elements (14) between a tubing and a surrounding casing (12) located in a wellbore and expanding the expandable elements against the casing so as to cause the tubing to centre within the casing; or expanding one or more portions (20) of a tubing against a surrounding casing located in a wellbore so as to cause the tubing to centre within the casing.

Abstract: A method of sealing a well comprises creating one or more openings in a tubing installed in a wellbore, in a location for a well seal; using a wireline to locate a stinger in that location; setting the stinger in that location; and forming a seal in the well in that location, by injecting sealant through said stinger.

Abstract: A method of plugging a well includes providing a tubing in a wellbore, wherein in a location for a well plug, the tubing is provided with an internal cable section placed inside of the tubing and/or an external cable section placed outside of the tubing, the external cable section including a fluid-tight cable suitable for forming a sealing part of the well plug, and forming a plug in the well in the location for the well plug without pulling the tubing from the wellbore.