摘要:
A system for cooling electronic components in the downhole assembly of a drill string through which a drilling fluid flows. The cooling system includes a thermoelectric cooler that conducts heat from the electronic component to a first heat transfer surface of a thermal conductor. The heat received by the first heat transfer surface is transferred within the thermal conductor to a second heat transfer surface that then transfers the heat to a housing. The housing transfers the heat to the drilling fluid flowing over the housing. To ensure good conductive heat transfer between the electronic component, the thermoelectric cooler, the thermal conductor and the housing, and to absorb shock, vibration and differential thermal expansion, these components are supported on a spring mechanism that generates a force that biases the electronic component against the thermoelectric cooler, the thermoelectric cooler against the thermal conductor and the thermal conductor against the housing.
摘要:
An impact dissipation tool for supporting a downhole tool in downhole applications. The tool includes a base and a housing. The tool also includes a carriage located within the housing and coupled to the base, the carriage being movable relative to the housing upon a predetermined impact force. A dissipator disposed inside the housing is collapsible due to the relative movement of the carriage and the housing. The collapse of the dissipator dissipates the impact force transferred to the downhole tool.
摘要:
The tool comprises one or more core-coil assemblies 2 jacketed in an non-magnetic and electrically insulating, tubular outer housing, 10. The housing enables high power transfer efficiency. A structural skeleton 20 extends longitudinally through the tool for axially reinforcement. The core-coil assemblies 2 are encapsulated in epoxy 77 to mechanically rigidify and protect them as well as to isolate the coil windings 51 from the power bus 23 extending longitudinally of the core-coil assemblies through a peripheral busway 60, 61.
摘要:
A well logging apparatus adapted to be moved inside a borehole includes an elongate body, a measuring pad adapted to contact the wall of the borehole, a support device for the pad mounted pivotally on one side of the body, and a counter arm which causes the pad to be applied against the wall of the borehole. The support device includes an arm which carries the weight of the pad and is connected to the pad substantially in the central part thereof.
摘要:
The invention concerns a well logging device with a pad, characterized in that the pad has a nuclear sensor with a gamma ray source and two detectors separated by a space in the longitudinal direction, and a second sensor of different type located in said space, preferably a micro-resistivity sensor with electrodes.
摘要:
A wellbore caliper includes an actuator housing pivotally connected at one end to a well logging instrument housing and an actuator disposed in the housing and operable to extend and retract laterally extensible measuring arms.
摘要:
An impact dissipation tool for supporting a downhole tool in downhole applications. The tool includes a base and a housing. The tool also includes a carriage located within the housing and coupled to the base, the carriage being movable relative to the housing upon a predetermined impact force. A dissipator disposed inside the housing is collapsible due to the relative movement of the carriage and the housing. The collapse of the dissipator dissipates the impact force transferred to the downhole tool.
摘要:
A flexible coupling for well logging instruments includes a housing coupled at one longitudinal end to one end of a second housing. Each of the housings defines a sealed interior chamber. The housings are coupled to enable angular deflection between respective longitudinal axes thereof. A conduit extends between the housings. The conduit is sealingly engaged to each housing such that longitudinal ends of the conduit are substantially positionally fixed with respect to each housing. The conduit is formed from material and has dimensions selected to withstand at least a same hydrostatic pressure as each of the housings. The conduit includes a bending strain distribution feature configured such that at a maximum angular deflection between housings a bending strain in the conduit is at most equal to an elastic limit of the conduit.
摘要:
A conveyance apparatus for conveying at least one logging tool through an earth formation traversed by a horizontal or highly deviated borehole. The conveyance apparatus comprises a pair of arcuate-shaped cams pivotally mounted to a support member, a spring member for biasing the arcuate surface of each cam into contact with the borehole wall, and actuators operatively connected to each cam. A logging tool is attached to the conveyance apparatus. When either actuator is activated in a first direction, the cam connected to the activated actuator is linearly displaced forward and the arcuate surface of the cam slides along the borehole wall. When either actuator is activated in a second direction, the activated actuator pulls the connected cam backwards and the spring member thereby urges the arcuate surface of the cam to lock against the borehole wall. Once the cam is locked, further movement of the actuator propels both the conveyance apparatus and the logging tool forward along the highly deviated or horizontal borehole.
摘要:
An impact dissipation tool for supporting a downhole tool in downhole applications. The tool includes a base and a housing. The tool also includes a carriage located within the housing and coupled to the base, the carriage being movable relative to the housing upon a predetermined impact force. A dissipator disposed inside the housing is collapsible due to the relative movement of the carriage and the housing. The collapse of the dissipator dissipates the impact force transferred to the downhole tool.