TELEMETRY DOWNHOLE TOOL Russian patent published in 2009 - IPC E21B47/12 G01D5/12 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to directional drilling equipment for oil and gas wells and is designed to transmit signals in the drilling process from the electronic unit of the downhole tool to ground equipment. Telemetry downhole tool includes an encased generator, a fastening device to secure same, and an enclosed electronic unit mounted on the upper and lower cross members in the electric separator so that there is an annular gap formed to let drilling mud pass inside, including electrically connected radiator and chassis with inclinometer sensors and electronics installed thereon. A distance insert made of low-conductivity material or metal is installed through a hole between the chassis and radiator with a hole axis running along conductors electrically connecting the radiator connector and chassis connector. The electronic unit housing consists of top and bottom halves with a heat-insulating layer between separate parts of the housing. There is at least one elastic ring between the distance insert and the inside of the electronic unit housing to prevent air convection between the radiator and chassis. The distance insert hole can be closed with elastic plugs and filled with thermally non-conductive material. There is also a heat insulator installed between the distance insert and radiator. The radiator is made of material that has higher temperature expansion than the material used for the top half of the electronic unit housing. The outer side face of the top half is grooved to augment the surface removing heat from the radiator.

EFFECT: heat-protected electronic components within downhole equipment, improved heat removal from the radiator, enhanced reliability of the downhole equipment and accuracy of azimuthal angle measurement.

7 cl, 4 dwg