A downhole tool for forming a seal in a wellbore includes a housing configured for attachment to a string usable to transport the tool in the wellbore to a target depth; a holding chamber disposed within the housing, the holding chamber configured to receive a combination of a metal, a metal oxide, and a negative thermal expansion material in the holding chamber; an initiator operable to initiate a chemical reaction; a pressure applicator configured to apply pressure to seal material in the holding chamber; and an opening in a surface of the housing through which the seal material is expellable from the holding chamber.

A downhole tool for forming a seal in a wellbore includes a housing configured for attachment to a string usable to transport the tool in the wellbore to a target depth; a holding chamber disposed within the housing, the holding chamber configured to receive a combination of a metal, a metal oxide, and a negative thermal expansion material in the holding chamber; an initiator operable to initiate a chemical reaction; a pressure applicator configured to apply pressure to seal material in the holding chamber; and an opening in a surface of the housing through which the seal material is expellable from the holding chamber.

The present invention is a system for repairing asphalt. The system includes a discrete quantity of an asphalt repair composition located within a container and an induction heater. The composition is a combination of an asphalt binder, aggregate particles, and induction particles. The average diameter of the induction particles ranges from approximately 10% above to approximately 10% below an average diameter of the aggregate particles used in the composition. The induction heater heats the composition within the container by generating a magnetic field that penetrates the container. The magnetic field creates eddy currents in the induction particles. These eddy currents in turn heat the composition. Because the induction particles are distributed throughout the composition, the composition heats rapidly.

The present invention is a system for repairing asphalt. The system includes a discrete quantity of an asphalt repair composition located within a container and an induction heater. The composition is a combination of an asphalt binder, aggregate particles, and induction particles. The average diameter of the induction particles ranges from approximately 10% above to approximately 10% below an average diameter of the aggregate particles used in the composition. The induction heater heats the composition within the container by generating a magnetic field that penetrates the container. The magnetic field creates eddy currents in the induction particles. These eddy currents in turn heat the composition. Because the induction particles are distributed throughout the composition, the composition heats rapidly.

A method of sealing propagating cracks in a sensor-laden cement sheath comprising the steps of monitoring an electrical resistivity of the sensor-laden cement sheath to produce a measured value, wherein the sensor-laden cement sheath comprises a conductive sensor, an on-demand expanding agent, and a cement, activating a heat source when the measured value of the electrical resistivity is greater than an activation threshold, increasing a temperature of the sensor-laden cement sheath with the heat source to an activation temperature, wherein the activation temperature is operable to initiate a reaction between the on-demand expanding agent and water, wherein the activation temperature is greater than a formation temperature, reacting the on-demand expanding agent with water to produce a swelled agent, wherein the swelled agent occupies a greater volume than the on-demand expanding agent, and sealing the propagating cracks in the sensor-laden cement sheath with the swelled agent.

A method of sealing propagating cracks in a sensor-laden cement sheath comprising the steps of monitoring an electrical resistivity of the sensor-laden cement sheath to produce a measured value, wherein the sensor-laden cement sheath comprises a conductive sensor, an on-demand expanding agent, and a cement, activating a heat source when the measured value of the electrical resistivity is greater than an activation threshold, increasing a temperature of the sensor-laden cement sheath with the heat source to an activation temperature, wherein the activation temperature is operable to initiate a reaction between the on-demand expanding agent and water, wherein the activation temperature is greater than a formation temperature, reacting the on-demand expanding agent with water to produce a swelled agent, wherein the swelled agent occupies a greater volume than the on-demand expanding agent, and sealing the propagating cracks in the sensor-laden cement sheath with the swelled agent.

The present invention concerns the field of refining metal melts or slags and provides in particular a reactive material based on calcium aluminate and carbon, its process of preparation and various methods for refining metal melts using the same.

The present invention concerns the field of refining metal melts or slags and provides in particular a reactive material based on calcium aluminate and carbon, its process of preparation and various methods for refining metal melts using the same.

The invention provides novel aerated composite materials made from a carbonatable calcium silicate composition, and formulations and methods of manufacture and use thereof, in particular, the use of novel additive mineral compositions in the form of magnesium, magnesium salts or magnesium oxides, to improve physical chemical properties of low density concrete materials. The low density, aerated material is comprised of calcium carbonate (CaCO.sub.3) and silica (SiO.sub.2), as cured products of carbonatable calcium silicate compositions.

The invention provides novel aerated composite materials made from a carbonatable calcium silicate composition, and formulations and methods of manufacture and use thereof, in particular, the use of novel additive mineral compositions in the form of magnesium, magnesium salts or magnesium oxides, to improve physical chemical properties of low density concrete materials. The low density, aerated material is comprised of calcium carbonate (CaCO.sub.3) and silica (SiO.sub.2), as cured products of carbonatable calcium silicate compositions.