Abstract: A method for providing a permanent barrier in a well includes lowering a first, particulate constituent of a pyrotechnic mixture to a desired location in the well, wherein the first constituent is a metal oxide. The method further includes waiting a first predetermined period of time to allow the first, particulate constituent to settle as sediment at the desired location, lowering a second constituent of the pyrotechnic mixture to the desired location in the well, wherein the second constituent is a metal, and igniting the pyrotechnic mixture to start a heat generating exothermic reduction-oxidation process.

Abstract: A method creates and verifies a thermite-based downhole well barrier in a well. The method includes lowering a heat generating mixture to a desired location in the well; and igniting the heat generating mixture, thereby starting a heat generating process. The method further includes measuring a parameter (P(t)) representative of fluid pressure and/or fluid flow at an upper location of the well as a function of time, at least from time of ignition of the heat generating mixture. The method further includes identifying a first peak area of the measured parameter (P(t)); and determining that the integrity of the well barrier is intact by comparing the first peak area with a first peak area of an expected parameter (E(t)).

Abstract: The present invention relates to a downhole pressure equalizer comprising an elongated housing comprising a piston compartment having a first end provided in fluid communication with an outside of the elongated housing and a second end provided in fluid communication with a process chamber of a well tool. A piston device provided in the position compartment comprises an outer piston section slidingly and sealingly engaged with the piston compartment; and an inner piston section slidingly and sealingly engaged within the through bore of the outer piston section.

Abstract: The present invention relates to a well tool system for forming a permanent barrier in a well, the system comprising: a well tool device comprising a pyrotechnic mixture and an ignition device provided within or adjacent to the pyrotechnic mixture; a tool string connected above the well tool device; and a replenishment string connected between the well tool device and tool string. The replenishment string comprises pyrotechnic mixture. The elevating device is configured to control the movement of the replenishment string towards a heat generating process started by means of the ignition device.

Abstract: This invention relates to a thermite reaction charge comprising bismuth oxide and aluminium adapted to react with a reaction rate giving a reaction time of 8 to 15 seconds for a thermite reaction charge of 30 to 100 kg from initialisation of the thermite reaction charge to at least 90% of the thermite reaction charge is reacted, a method for forming a three-phased rock-to-rock barrier by applying the thermite reaction charge and a well barrier formed thereof.

Abstract: A method for providing a permanent barrier in a well includes lowering a first, particulate constituent of a pyrotechnic mixture to a desired location in the well, wherein the first constituent is a metal oxide. The method further includes waiting a first predetermined period of time to allow the first, particulate constituent to settle as sediment at the desired location, lowering a second constituent of the pyrotechnic mixture to the desired location in the well, wherein the second constituent is a metal, and igniting the pyrotechnic mixture to start a heat generating exothermic reduction-oxidation process.

Abstract: A method for providing a permanent barrier in a well includes lowering a first, particulate constituent of a pyrotechnic mixture to a desired location in the well, wherein the first constituent is a metal oxide. The method further includes waiting a first predetermined period of time to allow the first, particulate constituent to settle as sediment at the desired location, lowering a second constituent of the pyrotechnic mixture to the desired location in the well, wherein the second constituent is a metal, and igniting the pyrotechnic mixture to start a heat generating exothermic reduction-oxidation process.

Abstract: The present invention relates to a downhole pressure equalizer comprising an elongated housing comprising a piston compartment having a first end provided in fluid communication with an outside of the elongated housing and a second end provided in fluid communication with a process chamber of a well tool. A piston device provided in the position compartment comprises an outer piston section slidingly and sealingly engaged with the piston compartment; and an inner piston section slidingly and sealingly engaged within the through bore of the outer piston section.

Abstract: The present invention relates to a method for providing a permanent barrier in a well. Step a) comprises lowering a first, particulate constituent of a pyrotechnic mixture to a desired location in the well; wherein the first constituent is a metal oxide. Step b) comprises waiting a first predetermined period of time to allow the first, particulate constituent to settle as sediment at the desired location. Step c) comprises lowering a second constituent of the pyrotechnic mixture to the desired location in the well; wherein the second constituent is a metal. Step d) comprises igniting the pyrotechnic mixture to start a heat generating exothermic reduction-oxidation process.

Abstract: The present invention relates to a well tool system for forming a permanent barrier in a well, the system comprising: a well tool device comprising a pyrotechnic mixture and an ignition device provided within or adjacent to the pyrotechnic mixture; a tool string connected above the well tool device; and a replenishment string connected between the well tool device and tool string. The replenishment string comprises pyrotechnic mixture. The elevating device is configured to control the movement of the replenishment string towards a heat generating process started by means of the ignition device.

Abstract: This invention relates to a thermite reaction charge comprising bismuth oxide and aluminium adapted to react with a reaction rate giving a reaction time of 8 to 15 seconds for a thermite reaction charge of 30 to 100 kg from initialisation of the thermite reaction charge to at least 90% of the thermite reaction charge is reacted, a method for forming a three-phased rock-to-rock barrier by applying the thermite reaction charge and a well barrier formed thereof.

Abstract: A downhole system includes a drill string having a drilling fluid flow channel and at least one turbine alternator deployed in the flow channel. The turbine alternator is configured to convert flowing drilling fluid to electrical power. A voltage bus is configured to receive electrical power from the turbine alternator and at least one electrical motor is configured to receive electrical power from the voltage bus. An electronic controller is configured to provide active control of the turbine alternator via processing a desired speed of the electrical motor to generate a desired torque current and feeding the desired torque current forward to the turbine alternator. The turbine alternator is responsive to the desired torque current such that it modifies the electrical power provided to the voltage bus in response to the desired torque.

Abstract: A downhole system includes a drill string having a drilling fluid flow channel and at least one turbine alternator deployed in the flow channel. The turbine alternator is configured to convert flowing drilling fluid to electrical power. A voltage bus is configured to receive electrical power from the turbine alternator and at least one electrical motor is configured to receive electrical power from the voltage bus. An electronic controller is configured to provide active control of the turbine alternator via processing a desired speed of the electrical motor to generate a desired torque current and feeding the desired torque current forward to the turbine alternator. The turbine alternator is responsive to the desired torque current such that it modifies the electrical power provided to the voltage bus in response to the desired torque.

Abstract: A downhole system includes a drill string having a drilling fluid flow channel and at least one turbine alternator deployed in the flow channel. The turbine alternator is configured to convert flowing drilling fluid to electrical power. A voltage bus is configured to receive electrical power from the turbine alternator and at least one electrical motor is configured to receive electrical power from the voltage bus. An electronic controller is configured to provide active control of the turbine alternator via processing a desired speed of the electrical motor to generate a desired torque current and feeding the desired torque current forward to the turbine alternator. The turbine alternator is responsive to the desired torque current such that it modifies the electrical power provided to the voltage bus in response to the desired torque.

Abstract: A downhole generator system including a controlled rectifier for receiving electrical power from a generator and outputting rectified electrical power. A control system controls the operation of the controlled rectifier and a chopper circuit connected to the output of the controlled rectifier connects a load selectively across the output of the controlled rectifier to regulate the output of the generator system. The control system controls the chopper circuit and/or the controlled rectifier based at least in part on a feed-back signal representative of an electric current output by the generator system and an electric current passing through the chopper circuit.

Abstract: A downhole system includes a drill string having a drilling fluid flow channel and at least one turbine alternator deployed in the flow channel. The turbine alternator is configured to convert flowing drilling fluid to electrical power. A voltage bus is configured to receive electrical power from the turbine alternator and at least one electrical motor is configured to receive electrical power from the voltage bus. An electronic controller is configured to provide active control of the turbine alternator via processing a desired speed of the electrical motor to generate a desired torque current and feeding the desired torque current forward to the turbine alternator. The turbine alternator is responsive to the desired torque current such that it modifies the electrical power provided to the voltage bus in response to the desired torque.