Abstract: A method of sealing a subsurface bore comprises: locating a volume of thermite in the bore; locating a volume of alloy in the bore with the thermite; initiating reaction of the thermite to heat the alloy; and bringing the alloy to above the melting point of the alloy whereby the alloy flows and occludes the bore. The thermite may retain its initial form during or following reaction or may partially fluidise. The thermite may react to provide a platform that at least partially occludes the bore. The alloy may flow over a surface of the thermite.

Abstract: A downhole tool comprises a heater including a container enclosing a volume of compacted thermite. A volume of flowable alloy is provided above the heater. A fusible bulkhead may be provided between the heater and the alloy and provides for direct conduction of heat from the heater to the alloy. A housing containing the alloy may be separated from the heater by heating a fusible socket that anchors an end of a tensioned support member. The thermite may define an internal volume adapted to receive alloy. The heater may be activated to melt the alloy and the alloy may then solidify to form a bore-sealing plug.

Abstract: A downhole method comprises expanding a patch member. The patch member may be employed in a method of sealing a wall of a bore. The sealing method may comprise: providing the patch member with a sealing material on an exterior surface; running the patch member into the bore in a smaller diameter first configuration; heating the sealing material to render the sealing material flowable; reconfiguring the patch member to a larger diameter second configuration; and hardening the sealing material to provide a seal between the exterior surface of the patch member and an inner surface of the bore.

Abstract: A method of sealing a subsurface bore comprises: locating a volume of thermite in the bore; locating a volume of alloy in the bore with the thermite; initiating reaction of the thermite to heat the alloy; and bringing the alloy to above the melting point of the alloy whereby the alloy flows and occludes the bore. The thermite may retain its initial form during or following reaction or may partially fluidise. The thermite may react to provide a platform that at least partially occludes the bore. The alloy may flow over a surface of the thermite.

Abstract: Methods and apparatus for forming platforms and flow control features in underground wells is described, using modified thermite reactions to form a ceramic plug in place. The reactive package is engineered to expand laterally, filling the well, and may be used to form a ceramic bridge plug, porous ceramic screen sections, or mitigate lost circulation of drilling fluids. These objectives are achieved through the design of the reactive package and through use of carefully chosen reaction additives that control the molten product rheology, solidification temperature, and pore generations and sustainment.

Abstract: Methods and apparatus for forming platforms and flow control features in underground wells is described, using modified thermite reactions to form a ceramic plug in place. The reactive package is engineered to expand laterally, filling the well, and may be used to form a ceramic bridge plug, porous ceramic screen sections, or mitigate lost circulation of drilling fluids. These objectives are achieved through the design of the reactive package and through use of carefully chosen reaction additives that control the molten product rheology, solidification temperature, and pore generations and sustainment.

Abstract: A platform is formed in a well below a target plug zone by lowering a thermite reaction charge into the well and igniting it, whereby the products of the reaction are allowed to cool and expand to form a platform or support in the well. A main thermite reaction charge is placed above the platform and ignited to form a main sealing plug for the well. In some embodiments an upper plug is formed by igniting an upper thermite reaction charge above the main thermite reaction charge. The upper plug confines the products of ignition of the main thermite reaction charge.

Abstract: A platform is formed in a well below a target plug zone by lowering a thermite reaction charge into the well and igniting it, whereby the products of the reaction are allowed to cool and expand to form a platform or support in the well. A main thermite reaction charge is placed above the platform and ignited to form a main sealing plug for the well. In some embodiments an upper plug is formed by igniting an upper thermite reaction charge above the main thermite reaction charge. The upper plug confines the products of ignition of the main thermite reaction charge.

Abstract: Wells are sealed by means of thermite reaction charges inserted into the wells. The reaction charge can be diluted by addition of metal oxides, silica, or the like control reaction pressure, peak temperature, reaction rate, and expansion characteristics of the resulting thermite plug. The use of dilution of the thermite reactants can take the form of a thermite charge with specific layers, including relatively high and low reaction temperature layers. The ignition source can be oriented to achieve directional control on the product expansion including radial or axial expansion. The charge can be loaded with a large mass to compress the resulting thermite plug into the borehole wall and reduce its porosity during the reaction process. A further variation involves continuous feed of the thermite reactants to the reaction zone. Various combinations and permutations of the above inventive concepts are described.

Abstract: Wells are sealed by means of thermite reaction charges inserted into the wells. The reaction charge can be diluted by addition of metal oxides, silica, or the like control reaction pressure, peak temperature, reaction rate, and expansion characteristics of the resulting thermite plug. The use of dilution of the thermite reactants can take the form of a thermite charge with specific layers, including relatively high and low reaction temperature layers. The ignition source can be oriented to achieve directional control on the product expansion including radial or axial expansion. The charge can be loaded with a large mass to compress the resulting thermite plug into the borehole wall and reduce its porosity during the reaction process. A further variation involves continuous feed of the thermite reactants to the reaction zone. Various combinations and permutations of the above inventive concepts are described.

Abstract: Wells are sealed by means of thermite reaction charges inserted into the wells. The reaction charge can be diluted by addition of metal oxides, silica, or the like control reaction pressure, peak temperature, reaction rate, and expansion characteristics of the resulting thermite plug. The use of dilution of the thermite reactants can take the form of a thermite charge with specific layers, including relatively high and low reaction temperature layers. The ignition source can be oriented to achieve directional control on the product expansion including radial or axial expansion. The charge can be loaded with a large mass to compress the resulting thermite plug into the borehole wall and reduce its porosity during the reaction process. A further variation involves continuous feed of the thermite reactants to the reaction zone. Various combinations and permutations of the above inventive concepts are described.

Abstract: Wells are sealed by means of thermite reaction charges inserted into the wells. The reaction charge can be diluted by addition of metal oxides, silica, or the like control reaction pressure, peak temperature, reaction rate, and expansion characteristics of the resulting thermite plug. The use of dilution of the thermite reactants can take the form of a thermite charge with specific layers, including relatively high and low reaction temperature layers. The ignition source can be oriented to achieve directional control on the product expansion including radial or axial expansion. The charge can be loaded with a large mass to compress the resulting thermite plug into the borehole wall and reduce its porosity during the reaction process. A further variation involves continuous feed of the thermite reactants to the reaction zone. Various combinations and permutations of the above inventive concepts are described.

Abstract: Wells are sealed by means of thermite reaction charges inserted into the wells. The reaction charge can be diluted by addition of metal oxides, silica, or the like control reaction pressure, peak temperature, reaction rate, and expansion characteristics of the resulting thermite plug. The use of dilution of the thermite reactants can take the form of a thermite charge with specific layers, including relatively high and low reaction temperature layers. The ignition source can be oriented to achieve directional control on the product expansion including radial or axial expansion. The charge can be loaded with a large mass to compress the resulting thermite plug into the borehole wall and reduce its porosity during the reaction process. A further variation involves continuous feed of the thermite reactants to the reaction zone. Various combinations and permutations of the above inventive concepts are described.

Abstract: Wells are sealed by means of thermite reaction charges inserted into the wells. The reaction charge can be diluted by addition of metal oxides, silica, or the like control reaction pressure, peak temperature, reaction rate, and expansion characteristics of the resulting thermite plug. The use of dilution of the thermite reactants can take the form of a thermite charge with specific layers, including relatively high and low reaction temperature layers. The ignition source can be oriented to achieve directional control on the product expansion including radial or axial expansion. The charge can be loaded with a large mass to compress the resulting thermite plug into the borehole wall and reduce its porosity during the reaction process. A further variation involves continuous feed of the thermite reactants to the reaction zone. Various combinations and permutations of the above inventive concepts are described.

Abstract: The present invention is a soil remediation system which uses naturally occurring barometric pressure oscillations to remediate volatile contamination in the vadose zone. By applying a surface seal, a collection plenum and a unidirectional gas relief valve to the soil surface above the contaminant plume, the present invention induces a net upward soil gas velocity in the contaminated soil. The sinusoidal velocity of the soil gas is rectified by the present invention to eliminate or minimize its downward velocity component and allow a normal upward velocity component. The resulting net upward velocity sweeps contaminant vapors from the source, releasing them up to the atmosphere through the gas relief valve in small concentrations. This process is regular and steady, and is accomplished without the use of ground bore holes, off-gas treatment or onsite power.