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Patent Searching and Data

Document Type and Number:
WIPO Patent Application WO/2014/170361
Kind Code:
The present invention relates to a downhole wireline tool for performing an operation in a well at a depth of up to 15 km downhole, the tool being powered by direct current at a predetermined voltage in a first end by a power supply unit which is configured to provide a specific steady-state voltage selected from a plurality of predetermined voltages, comprising an electrical motor being powered by alternating current, a frequency converter arranged between the first end and the motor, and a voltage peak reduction unit adapted to reduce the steady-state voltage of the selected power supplied to the frequency converter from the power supply, the voltage peak reduction unit comprising a capacitor, wherein the capacitor is a high temperature capacitor having a dielectric comprising a material capable of resisting a temperature above 150°C. Furthermore, the present invention relates to a downhole tool string and to a method of protecting a frequency converter from peaks of voltage in power supplied to the frequency converter in a downhole tool according to the present invention.

HALLUNDBÆK, Jørgen (Haregabsvej 15, Esbønderup Skovhuse, Græsted, DK-3230, DK)
NØRGAARD, Anders Just (Holmevej 38, Virum, DK-2830, DK)
Application Number:
Publication Date:
May 14, 2015
Filing Date:
April 16, 2014
Export Citation:
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WELLTEC A/S (Gydevang 25, Allerød, DK-3450, DK)
International Classes:
E21B43/12; E21B4/04; E21B4/18; H02H9/04
Attorney, Agent or Firm:
HOFFMANN DRAGSTED A/S (Rådhuspladsen 16, København V, DK-1550, DK)
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