Abstract: The disclosure relates to a sensor transportation apparatus to convey an elongate sensor assembly through a wellbore. The sensor transportation apparatus comprises at least one engagement structure to connect the sensor transportation apparatus to the sensor assembly, and a pair of wheels arranged to rotate about an axis of rotation substantially perpendicular to a longitudinal axis of the sensor assembly when the transportation apparatus is connected to the sensor assembly, and an orientation structure comprising at least one orientation projection, in a transverse outline of the sensor transportation apparatus a said orientation projection extending between the pair of wheels so that the shortest distance between a centre of mass of the elongate sensor assembly and the wellbore wall is when the pair of wheels are in contact with the wellbore wall.

Abstract: A double-layer coiled tubing double-gradient drilling system, on the basis of conventional drilling equipment, includes a double-layer coiled tubing system, separating fluid, a downhole lifting pump system, throttling control systems and a data monitoring system. Power fluid enters an annular space of the tubing through an adapter, passes through a downhole lifting pump, enters an inner pipe through a bridge channel, and enters the bottom hole through the drill bit. Return fluid enters an annular channel of the tubing through a recovery hole, then enters the inner pipe through the bridge channel and enters the lifting pump, and then enters a solid control system through the adapter and the control systems in sequence. Gradient control of the bottom hole pressure is realized through monitoring of the separating fluid and control of the drilling pump unit and throttling control systems. The problem of narrow safe drilling density window is solved.

Abstract: A method for predicting formation permeability by measuring diffusional tortuosity in several directions by pulse gradient NMR. The method comprises evaluating an anisotropic diffusion coefficient by pulsed gradient NMR, determining diffusional tortuosity from the restricted diffusion data, supplementing the NMR results with resistivity and sonic logging data, measuring anisotropic tortuosity and porosity by resistivity and sonic data and combining all components in a single fitting model. The 11-coefficient model is trained to recognize the true values of permeability by comparing the real oil permeabilities measured. in a library of oil-carrying rock cores with the NMR, resistivity and sonic correlates The fitting coefficients are extracted by minimizing the discrepancy between the laboratory measured permeabilities and the predicted values combining all rapid logging information components with the agreement-maximizing weights.

Abstract: A method for predicting formation permeability by measuring diffusional tortuosity in several directions by pulse gradient NMR. The method comprises evaluating an anisotropic diffusion coefficient by pulsed gradient NMR, determining diffusional tortuosity from the restricted diffusion data, supplementing the NMR results with resistivity and sonic logging data, measuring anisotropic tortuosity and porosity by resistivity and sonic data and combining all components in a single fitting model. The 11-coefficient model is trained to recognize the true values of permeability by comparing the real oil permeabilities measured in a library of oil-carrying rock cores with the NMR, resistivity and sonic correlates. The fitting coefficients are extracted by minimizing the discrepancy between the laboratory measured permeabilities and the predicted values combining all rapid logging information components with the agreement-maximizing weights.

Abstract: A turbine-powered electrical submersible pump (ESP) that has intake and discharge ports. The ESP intakes wellbore fluid from the intake port at an intake pressure, pressurizes the fluid, and discharges the fluid from the discharge port at a discharge pressure higher than the intake pressure. A motor is coupled to and drives the ESP. A turbine generator has a flow passage disposed between turbine intake and discharge ports. The turbine intake port is fluidly coupled to the pump discharge port. The turbine generator generates electric power from the pressurized wellbore fluid flowing through the flow passage and is electrically coupled to the motor and powers the motor with the generated electric power. A rechargeable battery is electrically coupled to the motor and provides power to initially start the motor. The turbine generator is further electrically coupled to the battery and recharges the battery.

Abstract: A downhole buried utility sensing and data transmission system for connection at the lower end of a drill string has sensors capable of detecting the existence of various different types of buried utilities and objects and making calculations as to the radial separation distance between the detected utilities and the drill head and transmitting data between the down hole drill head to the surface. The sensors respond to material properties used to construct the utility lines or the energy fields created by the operation of these lines (pipes and cables) or from the energy associated with transmission of the particular utility service, including sound energy resulting from fluid flow and electromagnetic energy from electric currents.

Abstract: A downhole production well control system is provided for automatically controlling downhole tools in response to sensed selected downhole parameters. The production well having a production tubing string therein with multiple branches, i.e., zones. Communication and transmission of power (i.e. telemetry) over the production tubing string is by way of a combination of a hardwire system in the main borehole and a short hop system at the branches or laterals. Each zone includes a downhole control system and appropriate completion devices for controlling fluid flow. An acoustic or electromagnetic transceiver is associated with each control system for communication and/or transmission of power. An electrical conductor runs from the surface downhole along the production tubing string in the main borehole for communication and/or transmission of power, hardwired systems are well known.