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 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 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 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 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 method of transmitting power and/or data between downhole equipment and a surface through a circuit including an alternating current (AC) powered motor and its associated power cable for powering the downhole equipment is disclosed, where the data is transmitted at frequencies outside the normal operating ranges that are thought acceptable. Associated circuitry and apparatus for performing the method are disclosed.

Abstract: The invention discloses an apparatus and method for securing together longitudinal members for use in a well. A common application of the invention is for securing an electric submersible pumping assembly to a bypass tubing. Embodiments of the invention resist rotation of the members but allow the members a degree of axial movement with respect to each other. Thus differential thermal expansion of the members does not result in tension between the connections. During assembly of the members before deployment in the well, the various components which can make up the members can be moved and aligned axially with respect to each other in order fit together. This simplifies assembly of the various components.

Abstract: The invention discloses an apparatus and method for securing together longitudinal members for use in a well. A common application of the invention is for securing an electric submergible pumping assembly to a bypass tubing. Embodiments of the invention resist rotation of the members but allow the members a degree of axial movement with respect to each other. Thus differential thermal expansion of the members does not result in tension between the connections. During assembly of the members before deployment in the well, the various components which can make up the members can be moved and aligned axially with respect to each other in order fit together. This simplifies assembly of the various components.