Abstract: A system and method of monitoring a tubular structure is provided. The method includes: a) sensing one or more parameters relating to the tubular structure at spaced apart positions along the length of the tubular structure using a sensor module array having a plurality of sensor modules disposed in a cable attached to the tubular structure, the plurality of sensor modules producing communication signals representative of the sensed parameter at each position along the length of the tubular structure; and b) using a control unit to communicate with the sensor modules in the array, including receiving communication signals representative of the sensed parameter at each position along the length of the tubular structure, and processing the communications signals to produce information relating to the sensed parameter at the positions along the length of the tubular structure.

Abstract: A downhole instrument system for permitting continued operation a downhole instrument after one or more failure modes is provided. The downhole instrument system includes an electrical power supply in electrical communication with the downhole instrument via an electrical power connection comprising one or more lengths of electrical cable and one or more electrical cable terminations; a load monitor configured to monitor a load on the electrical power supply, wherein the monitored load is dependent on one or more failure modes related to the electrical power connection; and a power controller configured to control the electrical power supplied to the downhole instrument based on the monitored load.

Abstract: A well bore instrument system is provided. The well bore instrument system includes a cable for conveying control signals and data signals; sensors positioned along the cable; and a controller operable to send control signals to the sensors and receive sensor data signals from the sensors via the cable. The controller is configured to transmit the control signals to the sensors at a control signal bit rate, wherein a sensor of the sensors is configured to receive the control signals and transmit sensor data signals to the controller at a sensor data bit rate, and wherein the sensor data bit rate is greater than the control signal bit rate.

Abstract: A well bore fluid sensor is provided that includes an inner plate, a plurality of outer plates, first and second cable fixtures, and an electronics module. The inner plate defines a sensor interior cavity. The outer plates include a first outer plate and a second outer plate. The electronics module includes a resonant circuit and a power supply and is in signal communication with the inner plate and at least one of the first and second cable fixtures. The inner plate, the first and second outer plates, and the first and second cable fixtures are coupled together to form a unitary structure. The inner plate is electrically insulated from the first and second outer plates, the first and second cable fixtures. The first and second outer plates are electrically insulated from one another. The inner plate is capacitively coupled to the first and second outer plates.

Abstract: A connector is described, including a housing including an internal volume, a port in the housing for receiving a conduit and providing access to the internal volume, a sealing arrangement for sealing the internal volume in the housing and a seal integrity test system including a sensor coupled to the housing. The seal integrity test system is configured to provide a measurement based on the pressure inside the internal volume of the housing to establish the integrity of the sealing arrangement.

Abstract: A gauge system and method for monitoring well pressure at temperatures in excess of 300° C. used in permanent monitoring of oil and gas wellbores. The gauge system includes an analog output transducer and a long cable which is an extruded mineral insulated multi-core cable with a seam welded corrosion resistant metal outer sheath. The transducer is enclosed in a pressure tight corrosion resistant housing and the housing is pressure sealed to the metal outer sheath. The method includes applying signal conditioning and processing to the measurements to compensate for characteristics of the transducer, the cable and the environment and thereby provide continuous monitoring of the wellbore.

Abstract: A fluid sensor cable assembly and method uses one or more conductive bodies extending along an elongated core body for conducting a heating current to heat the cable assembly. The one or more conductive bodies also are configured to conduct an interrogation signal and to conduct reflections of the interrogation signal. One or more optical fibers extend along the length of the core body and include temperature sensitive elements at different locations along the length of the core body. The temperature sensitive elements measure heat flux out of the cable assembly at the different locations subsequent to heating the cable assembly and communicate the heat flux to a computer acquisition system.

Abstract: A fluid measurement system and method for determining component mixtures flowing in a conduit such as an oil well. The system includes a sensor wire for location in a well bore; a signal generator for injecting a high frequency signal along the wire; a data acquisition unit to record first reflected signals received from the wire; a system criteria unit to maintain a data set relevant to the system, and a processor unit operable to act upon the first reflected signals and the data set to establish an output indicative of component fluid within the well bore from which the mixture of fluids flowing within the well bore can be determined. An iterative process can be used with waveguide and probabilistic models.

Abstract: A data communications system and method for transmitting data over a string between a surface location and a sub-surface location in a well bore in which a load varying device at the sub-surface varies the mechanical load on the string to be indicative of the data and a load measuring apparatus at surface monitors the mechanical load on the string and decodes the data. Data transmission is described from a pump assembly through a sucker rod string. Embodiments of load varying devices using electrical generators, friction rollers and hydraulic and pneumatic brakes are also described.

Abstract: A system and method for transmitting data over a three phase power system between a surface and a sub-surface location. A first power supply providing a first AC power signal and a second power supply providing a second AC power signal are at the surface. A first powered module and a second powered module which provides a data communications signal are at the sub-surface. A cable connection is provided between the surface and the sub-surface to transmit the power and data communication signals. The data communications signal provides an indication of power applied to the second powered module and a power signal is varied in response to the applied power. The invention finds specific application monitoring down hole equipment such as an electrical submersible pump in a wellbore.

Abstract: A three phase power system provided with a data communications system and associated method of data transmission for transmitting data over a three phase power system between a surface and a sub-surface location for an arrangement such as an oil field electrical submersible pump, the data communications system comprising a cabled connection from a surface system to a sub-surface system; a power module coupled to the cabled connection via a tuned circuit tuned to a first frequency, a data signal module coupled to the cabled connection via a tuned circuit tuned to a second frequency, independently of the coupled power module so as to minimize interference between the power signal module and data signal module during operation.

Abstract: A data communications system and associated method of data transmission for transmitting data over a three phase power system between a surface and a sub-surface location for an arrangement such as an oil field electrical submersible pump, on each of the three conductors of a three phase cabled connection with an isolation mechanism operable to isolate any given conductor when a fault associated with that conductor is detected. With the system providing a separate AC signal and data transfer on each conductor isolation can be achieved while enabling continued operation.

Abstract: A fluid sensor cable assembly and method uses one or more conductive bodies extending along an elongated core body for conducting a heating current to heat the cable assembly. The one or more conductive bodies also are configured to conduct an interrogation signal and to conduct reflections of the interrogation signal. One or more optical fibers extend along the length of the core body and include temperature sensitive elements at different locations along the length of the core body. The temperature sensitive elements measure heat flux out of the cable assembly at the different locations subsequent to heating the cable assembly and communicate the heat flux to a computer acquisition system.

Abstract: A fluid measurement system (10, 110, 210) and method of fluid mix determination over a sampling length (25) in a well bore (12). A pulse generator is run in the well bore from which is suspended a cable (24) with two conductors having a length equal to the sampling length. A high frequency pulse is injected along the cable and from the detected response average propagation velocities over the various reflections are used to determine the mixture of fluids. Embodiments are described which improve the determination such as using a cable with sections of alternating impedance, helically wound cable, providing multiple signal generators, incorporating a mathematical model, analyzing the analog signal response, providing a reference cable and incorporating an optical distributed temperature sensor.

Abstract: A fluid measurement system and method for determining distributed measurement of a fluid type and a fluid velocity in a wellbore, pipeline or other conduit in which fluid is moving. Measurement is made by immersing one or more cables having sequential sampling sections in the fluid and monitoring a cooling effect across a cable on the sampling sections and the response to injection of a high frequency pulse each sampling section. A probabilistic model is then used to determine the distributed velocity and fluid types along the conduit.

Abstract: A gauge system and method for monitoring well pressure at temperatures in excess of 300° C. used in permanent monitoring of oil and gas wellbores. The gauge system includes an analogue output transducer and a long cable which is an extruded mineral insulated multi-core cable with a seam welded corrosion resistant metal outer sheath. The transducer is enclosed in a pressure tight corrosion resistant housing and the housing is pressure sealed to the metal outer sheath. The method includes applying signal conditioning and processing to the measurements to compensate for characteristics of the transducer, the cable and the environment and thereby provide continuous monitoring of the wellbore.

Abstract: A data communications system and method for transmitting data over a string between a surface location and a sub-surface location in a well bore in which a load varying device at the sub-surface varies the mechanical load on the string to be indicative of the data and a load measuring apparatus at surface monitors the mechanical load on the string and decodes the data. Data transmission is described from a pump assembly through a sucker rod string. Embodiments of load varying devices using electrical generators, friction rollers and hydraulic and pneumatic brakes are also described.

Abstract: A fluid measurement system and method for determining component mixtures flowing in a conduit such as an oil well. The system includes a sensor wire for location in a well bore; a signal generator for injecting a high frequency signal along the wire; a data acquisition unit to record first reflected signals received from the wire; a system criteria unit to maintain a data set relevant to the system, and a processor unit operable to act upon the first reflected signals and the data set to establish an output indicative of component fluid within the well bore from which the mixture of fluids flowing within the well bore can be determined. An iterative process can be used with waveguide and probabilistic models.

Abstract: A gauge system and method for monitoring well pressure at temperatures in excess of 300° C. used in permanent monitoring of oil and gas wellbores. The gauge system includes an analogue output transducer and a long cable which is an extruded mineral insulated multi-core cable with a seam welded corrosion resistant metal outer sheath. The transducer is enclosed in a pressure tight corrosion resistant housing and the housing is pressure sealed to the metal outer sheath. The method includes applying signal conditioning and processing to the measurements to compensate for characteristics of the transducer, the cable and the environment and thereby provide continuous monitoring of the wellbore.

Abstract: A three phase power system provided with a data communications system and associated method of data transmission for transmitting data over a three phase power system between a surface and a sub-surface location for an arrangement such as an oil field electrical submersible pump, the data communications system comprising a cabled connection from a surface system to a sub-surface system; a power module coupled to the cabled connection via a tuned circuit tuned to a first frequency, a data signal module coupled to the cabled connection via a tuned circuit tuned to a second frequency, independently of the coupled power module so as to minimise interference between the power signal module and data signal module during operation.