A method of conditioning a well bore featuring an annulus (50) between a bore-lining tubing (20) and a surrounding bore wall (110) comprises pumping conditioning fluid through an inner tubing (10) located within the bore-lining tubing (20) and into a portion of the well bore containing the bore-lining tubing to affect the temperature of the portion of the well bore containing the bore-lining tubing. The annulus (50) between the bore-lining tubing (20) and the surrounding bore wall (110) is at least partially filled with settable material (54). The affected temperature of the portion of the well bore containing the bore-lining tubing influences the setting of the settable material. For example, heating the bore may accelerate setting of the material, while cooling the bore may retard setting of the material.

Sealing a well above a barrier or plug, comprising the steps of lowering a first tool on a slickline (21), comprising a plurality of cartridges (26), these cartridges including a plurality of cartridges containing a thermite material at least a first thermite initiator cartridge (70) which includes an activation receiver (73) deploying these cartridges above the barrier or plug transmitting a first wireless signal to first thermite initiator cartridge (70) such that the first thermite initiator cartridge causes a thermite reaction at the said set of the cartridges (26) containing a thermite material.

A method of retaining material in a bore comprises running a tool comprising a retainer member and a fusible part into a bore with the retainer member in a retracted configuration. The tool is positioned at a desired location in the bore and the fusible part is heated to reconfigure the retainer member to an extended configuration in which the retainer member engages the bore wall.

A device for treating a bottom-hole formation of a wellbore comprises a firing head and seal block assembly at a proximal end thereof and a bullnose assembly at a distal end thereof. A carrier tube extends between the firing head and seal block assembly and the bullnose assembly. The carrier tube contains a combustible chemical composition which generates hydrochloric acid gas or hydrofluoric acid gas or a combination thereof when combusted. A dispersion tube extends from the carrier tube. The dispersion tube has a lateral opening. The lateral opening may be a slot or an aperture. There is a charge wire electrically connecting the firing head and sealing block assembly to the combustible chemical composition.

The present invention provides a method of sealing a region of a sand screen of an Open Hole Gravel Pack without the need to perforate the sand screen and a tool for use in such. The tool being a eutectic/bismuth based alloy well plugging/sealing tool (1) having a tubular heater body (2) with an internal cavity (4) capable of receiving a chemical heat source (105). The tool is provided with a quantity of eutectic/bismuth based alloy (3) around an outer surface of the heater body (2) such that it can be heated by the chemical heat source (105). In addition the tool (1) has an insulating sleeve (7) provided around an outer surface of the alloy (3), wherein the sleeve (7) is configured to provide a focused egress for the alloy (3) as it is melted by the chemical heat source (105).

A well cleanup process involves removing an impermeable filter cake from a formation face with thermochemical and chelating agents to allow formation fluids to flow from a reservoir to a wellbore. The method may be used with oil and water-based drilling fluids with varied weighting agents, e.g., bentonite, calcium carbonate, or barite. Such thermochemical agents may involve two salts, e.g., NO.sub.2.sup.− and NH.sub.4.sup.+, which, when mixed together, can generate pressure and heat, in addition to hot H.sub.2O and/or N.sub.2. For example, the thermochemical agents may comprise Na.sup.+, K.sup.+, Li.sup.+, Cs.sup.+, Mg.sup.2+, Ca.sup.2+, and/or Ba.sup.2+ with NO.sub.2.sup.− and NH.sub.4.sup.+ with F.sup.−, Cl.sup.−, Br.sup.−, I.sup.−, CO.sub.3.sup.2−, NO.sub.3.sup.−, ClO.sub.4.sup.−, and/or .sup.−OH. The thermochemical agents in combination with a chelator such as EDTA can removed the filter cake after 6 hours with a removal efficiency of 89 wt % for the barite filter cake in water based drilling fluid, exploiting the generation of a pressure pulse and heat which may disturb the filter cake and/or enhance barite dissolution and polymer degradation.

A well cleanup process involves removing an impermeable filter cake from a formation face with thermochemical and chelating agents to allow formation fluids to flow from a reservoir to a wellbore. The method may be used with oil and water-based drilling fluids with varied weighting agents, e.g., bentonite, calcium carbonate, or barite. Such thermochemical agents may involve two salts, e.g., NO.sub.2.sup.− and NH.sub.4.sup.+, which, when mixed together, can generate pressure and heat, in addition to hot H.sub.2O and/or N.sub.2. For example, the thermochemical agents may comprise Na.sup.+, K.sup.+, Li.sup.+, Cs.sup.+, Mg.sup.2+, Ca.sup.2+, and/or Ba.sup.2+ with NO.sub.2.sup.− and NH.sub.4.sup.+ with F.sup.−, Cl.sup.−, Br.sup.−, I.sup.−, CO.sub.3.sup.2−, NO.sub.3.sup.−, CiO.sub.4.sup.−, and/or .sup.−OH. The thermochemical agents in combination with a chelator such as EDTA can removed the filter cake after 6 hours with a removal efficiency of 89 wt % for the barite filter cake in water based drilling fluid, exploiting the generation of a pressure pulse and heat which may disturb the filter cake and/or enhance barite dissolution and polymer degradation.

A method for the removal of well bore damage, the method including performing an acid cleaning of one or more of a coiled tubing and the well bore using a hydrochloric acid mixture of 7 to 15 wt % hydrochloric acid and displacing the hydrochloric acid mixture with a first fresh water stream. After acid cleaning, a composition comprising at least 10 wt % acetic acid into the wellbore is injected into the wellbore. After injecting acetic acid, gel jetting of the well is performed with a gel mixture, and the gel mixture is subsequently displaced with a second fresh water stream. After gel jetting, an organic solvent mixture is injected into the well bore and allowing the organic solvent mixture to soak for 2 to 6 hours. Finally, a thermochemical mixture is injected into the well bore, thereby increasing temperature and pressure and cleaning build up from the well bore.

This disclosure describes a device and method of sealing perforations on a well casing inside a subterranean well. The device comprises a generally cylindrical sleeve having an open top and a closed bottom; a heater located inside the sleeve, the heater comprising a thermite mixture; an ignition mechanism that ignites the thermite mixture upon actuation; and a string connected to the heater ignition and detachably engages the sleeve. The method comprises lowering a body of meltable plugging material into the well casing near the perforations; lowering the plugging device into the well casing immediately on top of the body of meltable plugging material; melting the meltable plugging material by igniting the thermite thereby transferring heat to the body of meltable plugging material; forcing the molten plugging material into the perforations by pushing the plugging tool further downhole; cooling the plugging tool and the plugging material until the plugging material solidifies; disengaging the tubing string from the sleeve and retrieving the tubing string with the heater; and removing the sleeve and bismuth remaining in the well casing, but not in the perforations.

A method of sand consolidation is provided. The method includes injecting a consolidating fluid into a subterranean sand formation via a wellbore to saturate a portion of the subterranean sand formation in a target region surrounding the wellbore and displace a formation fluid present in the subterranean sand formation. Herein, the consolidating fluid comprises bitumen dissolved in an aromatic solvent. The method further includes injecting a composition comprising one or more heat-generating chemicals into the subterranean sand formation such that the portion of the subterranean sand formation in the target region is heated to a target temperature of at least 150° C. The method further includes injecting a gas comprising oxygen into the subterranean sand formation for a period sufficient to oxidize the bitumen in the target region into a residue present on sand grains to bind the sand grains together into a consolidated permeable matrix. A volume fraction of the residue in the consolidated permeable matrix in the target region is about 5-30%.