SU998732A1 - Method of heat insulation of pumping string in well - Google Patents

Description

The invention relates to methods for increasing the efficiency of thermal insulation during the injection of heat transfer fluids and can be used in thermal methods for the extraction of oil to protect casing strings and the surrounding cement stone and rock against high temperature.

There is a method of creating thermal insulation, which involves injecting aqueous solutions of inorganic salts, sodium silicate, vermiculite, and others into the shell annulus, and subsequently evaporating water to form a heat insulation layer in the form of a U film on the injection column. .

The disadvantage of the method lies in the high heat and energy costs. evaporation of the carrier fluid, in the duration of the evaporation process, as well as in the uneven distribution of the heat insulating layer due to the uneven evaporation of water from the solution.

The closest to the technical essence of the invention is a method of creating thermal insulation of an injection string in a well, including pumping a tubular column of water into the annular space of a tubular column through the mouth of the well and removing water from the mixture. Blowing from below with gas 1.2 3 However, the known method is not sufficiently effective due to incomplete removal of water from the aqueous suspension of basalt fiber pumped into the annular space and insufficient compaction of the heat insulating material.

The purpose of the invention is to improve the thermal insulation efficiency of casing casing.

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This goal is achieved by the fact that according to the method of creating thermal insulation of the injection string in the well, including pumping, into the annular space of the tubular column, an aqueous suspension of basalt fiber and removing water from the mixture by blowing gas from the bottom, basalt fiber is granulated by feeding coolant through the tube column

25 purging the aqueous suspension of alto fiber b with gas.

The drawing shows schematically the injection well for carrying out the method of creating its thermal

Claims (2)

30 isolation. The method for creating thermal insulation of the injection string in the well is as follows. After mixing in the cement mixing units of the calculated volume of basalt fiber and water, the resulting suspension through the wellhead 1 through the discharge column 2 and through the drying valve 3 is injected into the annular space 4 of the tubular tower. To center the injection. COLUMNS 2 with respect to the casing 5, the centralizers 6 are installed at equal intervals on the first one. After filling the annular space 4 with the suspension above the packer 7, fluid is removed from the annular space 4 either by filtering or blowing air at high pressure from the compressor. With visual inspection of the almost complete removal of fluid at the wellhead, the well should be considered prepared for technological evaporation of the remaining moisture. The holes of the valve-drier 3 under the differential pressure are closed, and a coolant with a boiling point of the fluid is injected into the well, depending on the depth. In the process of technological evaporation, the formation of a vapor phase occurs, which tends to break through the layer of thermal insulating material to the surface. The process of bubbling begins, in which the fine particles of thermal insulation material under the action of the upward flow rotate randomly in contact with each other both in the transverse and in the diametrical direction, turning into small, indefinite granules. As the moisture evaporates from the suspension, the granules precipitate, accumulate and condense in the annular space 4, and fill it up to the mouth. With the full release of wet steam from the annulus should be considered well prepared to work. The technical and economic efficiency of the method consists in reducing the material costs for the creation of a thermally insulated tubular column. DETAILED DESCRIPTION OF THE INVENTION A method for insulating an injection string in a well, including pumping an aqueous suspension of basalt fiber into the annular space of a tubular column and removing water from the mixture by blowing it from the bottom, which is characterized by the fact that basalt fiber is granulated by feeding through the tubular column coolant, after purging the aqueous suspension of basalt fiber with gas. Sources of information taken into account in the examination 1. US patent 3,664,425, cl. 166-303, 1972. 2.AEVOR certificate of the USSR № 3218780/03, cl. E 21 V 36/00, 1980 (prototype).