SU947387A1 - Method of extracting metal objects from boreholes - Google Patents

Description

(54) METHOD FOR EXTRACTING METAL PREDAHETS

FROM WELLS

The invention relates to the drilling of wells, and in particular to methods for extracting metal objects of complex shape from wells / filled with liquid.

A known method for extracting metal objects located at the bottom is made by means of magnets.

The disadvantage of this method is the possibility of extracting metallic objects of light weight and free lying on the bottom of a well.

The closest to the proposed technical essence and the achieved result is a method of extracting metal objects from wells, including the descent of the catcher and its connection with the extraction 1 1M subject thermite welding i2j.

The disadvantage of this method lies in the low efficiency in the extraction of objects of complex shape.

The purpose of the invention is to increase the efficiency of work when extracting objects of complex configuration.

This goal is achieved by the fact that before welding the voids in the body

The item to be removed is filled with a plastic plugging composition, for example, clay with magnesite sand.

To work in wells with a diameter of 190-243 mm, 7 to 12 kg of thermite is required. lifting force of the device depending on the surface area of the extracted surface

10 of the metal well ranges from 500 to 2000 kg.

To protect the melted components of the burned thermite mixture from flowing out of the recoverable metal, a plastic Tc1fusion 11 coc-faB is used. Its mass is selected depending on the size of the holes and grooves in the metal, which need to be tamped. For work in wells with a 190-243 mm diameter, this mass is 12-18 kg. The tamponing composition must be plastic to

25 it is easy to penetrate the holes in the metal. It must withstand temperatures up to several minutes before the moment of cristacisation of molten iron and alumina.

Claims (2)

30 Clay, clay with magnesite sand or other similar substances and mixtures can be used for this purpose. The method is carried out as follows. Under the casing of the catcher with a thermite mixture have a plastic plugging composition. The catcher is lowered into the well on the pipes. Upon reaching the bottom, an axial force is transmitted to the plugging composition, which is caught in the holes and pores of the metal. After this, the thermite composition in the catcher is set on fire. The most convenient for this work is aluminum termite, which is sostoit from metallic aluminum in the form of coarse-grained powder or grits, usually with a grain size of about 1 mm, and from iron oxide with approximately the same grain size. Termite burns in 20-30 . To increase the rate of combustion, it can be compressed to a pressure of 30-70 MPa. Termite burns through the reaction 3F ,, 04 8AI lAlj.Oo + 802 kcal 76% 24% 45% 55% When the termite burns, the temperature is about. The ignition of the pressurized termite is produced by powder mite through the igniter composition and the transition composition with a content of 40-60% termite. The igniter composition can consist of 88% BaO, 2 and. 12% magnesium or 68% MnO, 75% aluminum powder, 7.5% aluminum powder and 17% magnesium powder. Molten iron and alumina melt the upper layer of the recoverable metal and the body of the catcher. Gradually, the metal cools, crystallizes. The tamping composition prevents it from leaking outside the zone of contact of the catcher body with the metal. Welding of the catcher case to the metal being extracted occurs. The use of the proposed method in the drilling of wells significantly reduces the amount of expensive work on milling foreign metal, destroying it with torpedoes, and extracting pieces of metal to the surface. The output of mills, torpedoes, and other special polishing tools decreases. Application of the proposed method to eliminate accidents - only 50% of emergency wells have an economic effect of 150-200 thousand. Claim 1: A method for extracting metal objects from wells, including the descent of the catcher and its connection with the extracted object by thermite welding, characterized in that in order to increase the efficiency of work when removing items of complex configuration, before welding, the voids in the body of the extracted object are filled with a plastic plugging compound. 2. Method POP 1, characterized in that clay with magnesite sand is used as a plastic plugging composition. Sources of information taken into account during the examination 1. USSR author's certificate No. 6.36373, cl. E 21 May 31/06, 1977. 2. The patent of Great Britain No. 1446959, cl. In 3 V, pub. 1976 (prototype).