| 摘要 |
A method is described for the thermal insulation of a well fitted with a casing and into which a tubing is introduced, this method consisting in arranging in the annular space enclosed between the said tubing and the said casing a pregelled fluid exhibiting a flow threshold which is sufficient to oppose convection movements. More particularly, a grease is employed, made up of a mineral or synthetic oil and of a thickener which may be a sodium or lithium soap, a complex calcium, aluminium, sodium or lithium soap, a polyurea, alumina, talc, a silica gel, a clay, attapulgite, a carbon black, graphite, lime, calcium carbonate or fly ash. The method can be applied in the case of temperatures of between the ambient and more than 300 DEG C.
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