RU1788195C - Method of sealing of connections of pipes in borehole - Google Patents

Description

against mating surfaces and indication of the moment of molten metal - solder,

The closest technical solution to the proposed one is the technology of sealing the pipe joint in the well, including applying a sealing coating to the mating surfaces of the pipes, lowering the pipe in the well and cementing the lower pipe section, lowering the upper pipe section into the well, injecting cement to fix the upper and lower sections , then the upper section is planted on the conical part of the lower section - the prototype.

A disadvantage of the known method is that it does not provide at the junction of the section in the event of internal excessive pressures, as a result of which the casing is radially moved to break (disconnect) the docking assembly.

The purpose of the invention is to increase the tightness and strength of the pipe joint in the well.

This goal is achieved by the fact that according to the method of sealing pipe joints in a well, comprising applying a sealing coating to the mating surfaces of the pipes, lowering the pipe into the well and cementing the lower pipe section, lowering the upper pipe section into the well, injecting cement to fix the upper pipe section and subsequent combination of mating surfaces of the upper and lower sections. Soft metal is used as a sealing coating. Before the pipes are lowered into the well, on the inside of the pipes, an indicator in the form of magnetic inserts is installed under the mating surfaces by connecting them to the pipes with the soft metal of the sealing coating, and after the mating surfaces are combined, the position of the magnetic inserts is controlled and the pipes are heated at the joint the positions of the indicators (moreover, the heating is stopped after receiving a signal to disconnect the magnetic inserts).

The drawing schematically shows the implementation of the method of sealing the nodes of technological equipment for casing - docking nodes.

The following convoys are accepted in the drawing; - beginnings: 1 - well, 2 - upper casing string section, 3 - mating surface of the upper casing string section, 4 - lower casing string section, 5 - mating surface of the lower casing

casing string, 6 - soft metal coating (solder), 7 - cable, 8 - heater, 9 - sensor for indicators, 10 - indicators, 11 - ground equipment

. (heater power supply, visual indicators, indicators, depth gauge, winch).

The method is carried out as follows.

О Preliminarily, a soft metal coating is applied to the mating surfaces of the docking unit (for example, tin, lead, etc.), and on the inner surface of the casing pipes, above and below the mating

5 surfaces, magnetic indicators (pieces of a magnet) are soldered with the same metal. The lower section of the casing strings is lowered and cemented in the usual manner. After lowering the upper casing section

0 columns and cement mortar pumping into the boarded up space, the sections are docked and the upper section of the casing string is unloaded. Heater 8 with sensors 5 is lowered inside the casing on cable 7. Heater 8 is installed along the length of the cable 7 and the indicators for monitoring the passage of indicators 10, opposite the mating surfaces 3, 5 of the casing. Heats up.

0 As a result of temperature increase, the metal located on the mating surfaces and on the mounting of indicators 10 melts, since the upper section of the casing strings during work on

5, when joining the sections, it is unloaded, then the molten metal, interacting with parts of the mating surfaces, fills all the smallest gaps, and after the cessation of heating forms a monolithic connection

0 mating surfaces for high bond strength. At the same time, when the pipe section is heated, indicator magnets previously soldered to the pipe body are soldered and fall down, which

5 is fixed to the surface as indicated by the monitoring devices. The absence of indications of the magnetic label of the indicator indicates that the metal coating of the mating surfaces is molten, after which the heating is stopped.

PRI me R (implementation of the method). Before the sectional casing string is lowered into the well, low-melting metal, for example POS 10, POSSU 4-6 or similar, having a melting point of 250-300 ° С, 1-2 mm thick . On the inner surface of the casing.

below and above the mating planes, solder with constant solder constant mzgnit indicators. Then. they lower it into the well and cement in the usual way the lower section of the casing with the lower mating surface mounted on its head and an indicator magnet. After waiting for the cement hardening (RAM) of the lower section and preparation of the wellbore, the upper section of the casing strings having the mating surface with the indicator magnet in the lower part is lowered. Cement solution is injected into the annulus and the upper and lower sections of the casing are joined. Unload the upper section by 10-15 tons and fix it in this position at the wellhead. Then, a heater with sensors is lowered into the casing using a wireline cable. Along the length of the logging cable lowered into the borehole and the readings of the indicators for monitoring indicators in the pipe string, a heater is installed opposite the mating surfaces of the docking unit. The passage or installation of sensors opposite the indicators is fixed at the wellhead using visual control devices. Power is supplied to the heater and the portion of the mating surfaces of the casing strings is heated to a temperature above the melting point of the low-melting metal coating. Under the influence of the weight of the upper section of the casing pipes there is a movement - compression of the mating surfaces in the medium of molten metal. In this case, the liquid interlayer provides continuous filling of microcracks, the mating surfaces of the docking unit. When heating a section of the string, the indicators are sealed off from the inner wall of the casing and fall (settle down) to the bottom of the well. The moment of soldering of the magnets is recorded by visual observation instruments installed at the wellhead. The absence of magnetic marks indicates that the metal-solder is completely melted, after which the heating of the docking unit is stopped. During cooling and

crystallization of the liquid interlayer forms a metallic bond of the mating surfaces, resulting in a monolithic and high-strength connection of the docking station. Then, the heater with sensors is removed from the well and further construction work is carried out.

Using the proposed method of sealing the connecting units allows to increase the strength of the casing string due to the formation of metal bonds between the interfaced surfaces., To provide the required tightness under any conditions of complex loading, to exclude the possibility of disconnecting the connecting unit under the influence of internal overpressures, to reduce the time and materials to carry out work to eliminate leakage of the column, which in turn will increase the commercial speed of building the benefits of skazin.

Claims (1)

SUMMARY OF THE INVENTION A method for sealing pipe joints in a well, comprising applying a sealing coating to the mating surfaces of the pipes, lowering the pipe section into the well and cementing the lower pipe section, injecting the upper pipe section into the well, injecting cement to fix the upper pipe section and then combining the mating surfaces of the upper and lower sections, characterized in that, in order to increase the tightness and strength of the pipe joint in the well, soft metal is used as a sealing coating; Before the pipes are lowered into the well, on the inside of the pipes, indicators in the form of magnetic inserts are installed under the mating surfaces by connecting them to the pipes with the soft metal of the sealing coating, and after combining the mating surfaces, the position of the magnetic inserts is controlled and the pipes are heated at the joint and the location of the indicators, and the heating is stopped after receiving a signal to disconnect the magnetic inserts.