Abstract: A tracer release method for monitoring fluid flow in a well utilizes a deformable container having a liquid tracer material which container has an outlet which debouches into the neck portion of a venturi in a well conduit. The container has a wall which is at least partly exposed to the fluid pressure at the relatively wide in- or outlet of the venturi, so that an amount of tracer is injected continuously or discontinuously into the well effluents which is proportional to the pressure difference p across the venturi, which pressure difference p is indicative of the fluid density &rgr; and squared fluid velocity &ugr;.

Abstract: A method of drilling a borehole into a subsurface earth formation is-provided, the method including using a tubular drill string which includes at its lower end a bottom hole assembly comprising a drill bit, a drill steering system, and a surveying system, wherein the drill string includes a passageway for an auxiliary tool from a first position interior of the drill string above the bottom hole assembly to a second position wherein at least part of the auxiliary tool is exterior of the drill string below the bottom hole assembly, which passageway can be selectively closed, and which method also includes drilling so as to progress the drill string into the earth formation, until a tool operating condition is met; opening the passageway; passing an auxiliary tool from the first position through the passageway to the second position, and operating the auxiliary tool at the second position.

Abstract: A logging system for use in a wellbore formed in an earth formation is disclosed. The system comprises a tubular conduit (9) extending from surface into the wellbore and containing a body of wellbore fluid, a logging tool string (12) capable of passing from a position within the conduit to a position outside the conduit at a lower end part thereof and capable of being suspended by the conduit in said position outside the conduit, and a pressure pulse device (18) arranged within the conduit in a manner that the pressure pulse device is in data communication with the logging tool. The pressure pulse device is capable of generating pressure pulses in the body of wellbore fluid, said pressure pulses representing data communicated by the logging tool string to the pressure pulse device during logging of earth formation by the logging tool string.

Abstract: A system is provided for drilling and logging of a wellbore formed in an earth formation. The system comprises a drill string provided with an external recess extending in longitudinal direction of the drill string, a fluid passage for flow of drilling fluid from an upper end of the drill string to a lower end thereof, and a port providing fluid communication between the fluid passage and the recess. The system further comprises a logging tool string capable of passing through the fluid passage and from the fluid passage via the port into the recess, and a removable closure element adapted to selectively close the port.

Abstract: A method for determining a dimension in a motor is described. By applying Fourier analysis, a sequence of terms is obtained. Since the fifth harmonic is the most undesirable term, the minimization of the fifth harmonic term will make resultant waveform closer to sine wave. Based upon the above, a determination of an angle &dgr; (22) is described, wherein the fifth harmonic term of the sequence of terms is minimized. An electronic motor having a rotor (26) and a set of slot on said rotor surface (36) having a set of magnets (46) with a width &dgr; (22) along the circumference (30) of said rotor surface (36) is described. The width &dgr; (22) is determined by a method that includes applying Fourier analysis thereby a sequence of terms is obtained. Since the fifth harmonic is the most undesirable term, the minimization of the fifth harmonic term will make resultant waveform closer to sine wave.

Abstract: A tracer release method for monitoring fluid flow in a well utilizes a deformable container comprising a liquid tracer material which container has an outlet which debouches into the neck portion of a venturi in a well conduit. The container has a wall which is at least partly exposed to the fluid pressure at the relatively wide in- or outlet of the venturi, so that an amount of tracer is injected continuously or discontinuously into the well effluents which is proportional to the pressure difference p across the venturi, which pressure difference p is indicative of the fluid density &rgr; and squared fluid velocity &ugr;.

Abstract: A logging system for use in a borehole formed in an earth formation, comprising a tubular element to be installed in the borehole, and a logging member including a conduit having an inlet opening and being movable in radial direction of the tubular element between a retracted position in which the logging member is substantially arranged within the tubular element and an extended position in which the logging member extends beyond the tubular element so that said inlet opening is in fluid communication with the earth formation when the tubular element is installed in the borehole, the logging system further comprising an activating device for moving the logging member between the retracted position and the extended position thereof.

Abstract: A system is provided for drilling and logging of a wellbore formed in an earth formation. The system comprises a drill string provided with an external recess extending in longitudinal direction of the drill string, a fluid passage for flow of drilling fluid from an upper end of the drill string to a lower end thereof, and a port providing fluid communication between the fluid passage and the recess. The system further comprises a logging tool string capable of passing through the fluid passage and from the fluid passage via the port into the recess, and a removable closure element adapted to selectively close the port.

Abstract: A system for drilling and logging of a wellbore formed in an earth formation is provided. The system comprises a logging tool string and a drill string having a longitudinal channel for circulation of drilling fluid, the drill string including a port providing fluid communication between the channel and the exterior of the drill string, the channel and the port being arranged to allow the logging tool string to pass through the channel and from the channel through the port to a position exterior of the drill string. The system further comprises a removable closure element adapted to selectively close the port, wherein the logging tool string may be selectively connected to the closure element.

Abstract: A logging assembly for application in a wellbore formed in an earth formation is provided. The assembly comprises a casing suitable to be lowered through the wellbore and to be arranged in a selected part thereof, and a NMR logging device comprising magnetising means for inducing a magnetic field into a selected zone of the earth formation, antenna means for transmitting radio-frequency (RF) signals into the selected zone and for receiving response RF signals from the selected zone, and data collecting means for collecting data representing the response RF signals, which data collecting means is removably arranged in the interior of the casing. The means for inducing the magnetic field includes a magnetised section of the casing.

Abstract: The invention relates to a method of operating a logging tool in a wellbore, the wellbore formed in an earth formation, which wellbore is to be provided with a wellbore component, the method including the steps of: arranging the logging tool in a selected relationship relative to the component so that the logging tool is guided by the component through the wellbore during lowering of the component into the wellbore; lowering the component with the logging tool in the selected relationship, through the wellbore to the section of the wellbore; operating the logging tool so as to provide logging data of the earth formation surrounding the wellbore; and transferring the logging data to surface.