Method and device for carrying out interventions in wells where high temperatures prevail
AssigneeInstitut Francais du Petrole
InventorChristian Wittrisch
Life of this patent
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Abstract
A well tool such as a measuring sonde is arranged in a protective housing and introduced into a well at the end of a tubing. A retractable latching device fastens the tool to the housing and to an electrical transmission cable. The tubing is connected with a pumping assembly capable of circulating up to the housing a cooling fluid at a temperature lower than the temperature prevailing in the well and the tool is operated by moving the tool out of the housing and by bringing the tool regularly back into the housing, which is permanently cooled by the fluid.
Claims10
A method for carrying out interventions with a well tool in zones of a deflect well where high temperatures likely to damage the tool prevail, wherein the tool is set in a protective housing adapted to contain the tool totally, the housing being immovably attached to the end of a tubing;
- the tool is linked to the protective housing by means of a support frame fitted with a first plug and with first retractable means for anchoring the support frame to the housing;
- an electrical transmission cable fitted at the end thereof with a second plug complementary of the first plug and adapted to be plugged into the first plug in a delayed way in a wet medium in order to connect the tool in the well with a surface installation and with a second retractable means for fixing the second plug to said support frame, and the upper end of the tubing is connected with a pumping system capable of delivering into the housing a cooling fluid at a temperature lower than the temperature prevailing in the well in the zone of intervention of the tool;
- the method, in order to make the tool work in well zones where high temperature is likely to damage the tool prevail further comprising:
- linking the tool to the surface installation by said cable, bringing the tool into the housing thereof cooled by said fluid, as far as the end of the intervention zone which is furthest from the surface, and
- progressively withdrawing the tubing and carrying out interventions with the tool by removing the tool from the housing and by periodically driving the tool back into the cooled housing in order to lower the temperature of the tool.
A device for carrying out interventions with a well tool in zones of a deflect well where high temperatures likely to destroy the tool prevail, which comprises a tubing, a protective housing fastened to the end of the tubing and adapted to contain the tool totally, a support frame for the tool fitted with the first retractable means for anchoring the support frame to the housing and with a first plug, an electrical transmission cable fitted with a second plug adapted to be plugged and locked into the first plug in a delayed way in a wet medium in order to connect the tool with a surface installation, thermal insulation means associated with the tubing to limit the heat exchanger between the inside and outside of said tubing and the upper end of the tubing being connected with a pumping system capable of delivering into the housing a cooling fluid at a temperature lower than the temperature prevailing in the well in the zone of intervention of the tool.
Dependencies are inferred from the claim text.