SU1696677A1 - Heat-insulated drill pipe string - Google Patents

Abstract

The invention relates to the oil industry is intended for the extraction of high-viscous oil by thermal methods for steam injection wells. The goal is to increase operational reliability by improving the thermal insulation of the joints of the pipe sections in the column. For this, the end of the pipe section, opposite the end with the threaded section on the outer surface, is designed as a socket with a threaded section on the inner surface of the pipe section for engagement with the threaded section on the outer surface of the other end of the adjacent pipe section. The length of the outer pipe of the socket is longer than the length of the inner pipe of the socket and forms a gap with the latter. The magnitude of the difference between the indicated bell lengths and the gap size is equal to the distance between the outer and inner tubes of the column section. The flange forming the thrust surface at the socket part of the section is located at the base of the socket between the sections of the inner tube of the main section and the socket part. Install the section with the socket end on the elevator, then install the seal. Thereafter, the sections are joined together by screwing the threads and lowering the column into the well. The coolant is fed into the internal cavity of the heat-insulated column. 1 hp ff, 3 ill.

Description

The invention relates to the oil industry, in particular to the extraction of high-viscous oil by thermal methods for steam injection wells, and can be used in the isolation of pipelines for the transport of coolants.

The purpose of the invention is to increase reliability in operation by improving the thermal insulation of the joints of the pipe sections in the column.

Fig. 1 shows a thermally insulated column (pipe section junction assembly), section; in fig. 2 - pipe section of thermally insulated column, section; in fig. 3 shows the node I in FIG. one.

The heat-insulated column consists of pipe sections 1 connected by an assembly 2 with adjacent sections 3. Each section contains coaxially arranged outer 4 and inner 5 pipes forming an annular sealed space of width h for accommodating the heat insulating material 6. Pipes 4 and 5 are connected at the ends of the flanges 7 and 8. One of the pipes forming the section is pre-stressed. One of the pipe ends of the section is designed as a bell, containing

Yu

oh oh

Vj

The outer 9 and inner 10 pipe sections, the length of the outer pipe 9 of the socket is longer than the length h of the inner pipe 10 of the socket and is located from the latter at a distance h equal to the distance between the outer and inner pipes 4 and 5 of the column section. The difference in the lengths of the pipes 9 and 10 of the bell is equal to the distance h between the outer 4 and inner 5 pipes. At the same time, in the base of the bell, the outer pipe forms an inner gap 11. The joint of the pipe sections has a serrated section 12 on the outer surface of the pipe section from one of its ends and a threaded section 13 on the inner surface. The joint assembly also contains a seal 14 located between the stop surfaces formed by the end flange 8, connecting the outer and inner pipes of the sections from the thread 12 side, and the end flange 15 located at the base of the cross section between the inner pipe sections of the main section and the socket part. The flanges 8 and 15 have a liner in the form of crackers 16 and 17 (Fig. 3) from a material with a thermal conductivity lower than the thermal conductivity of the pipe material.

The manufacture of a heat-insulated column is carried out by assembling between them separate sections including an outer 4 and an inner 2 pipe.

The manufacture of individual sections is carried out as follows.

First, flanges 15 and 8 are made separately (Fig. 3). In this case, both halves of flanges with annular grooves 18 and 19 are positioned so that their longitudinal axes coincide, and the ends are in the same plane. Thereafter, wedge crumbs 15 and 16 are pressed into the resulting wedge grooves, forming a fixed connection. To prevent the crackers 16 and 17 from falling out, the edges of the annular counter-grooves 18 and 19 are rolled. Then welded contact welding flat ring holder 20, while the welding seams 21 and 22 must be continuous and tight.

Next, the shaped - bell-shaped ends 9 and 10 of the outer 4 and inner 5 pipes are formed by their landing or welding the corresponding flanges, welding the flange 8 with the outer pipe 4 by welding, and the flange 15 with the inner pipe 5. Then smooth them to a metallic shine, for example, with sand blasting the installation, the inner surfaces of the outer pipe 4 and the outer surface of the inner pipe 5, after which a layer of primary insulation is applied to the pipe 5, for example multi-layer fiberglass. Then, placing the inner pipe 5 in the outer pipe 4, the bell ends are interconnected, for example, by welding 23. After that, the inner pipe 5

is heated to a certain temperature in order to relieve the stress that arises during operation during the transportation of the heat transfer fluid, after lengthening the inner tube 5, its end (from the side

The 0 straight pipe section is connected to the same end of the outer pipe 4 by welding 24. After assembling the section, the space between the pipes 5 and 4 is additionally insulated by evacuating

5 to improve the quality of the insulation. Vacuuming is performed by any of the known methods.

Then cut the threads 12 and 13, respectively, at the site of the pipe 4 and at the site

0 of the socket part 10 and prepare a place for the seal 14 (FIG. 1), for which the end faces of the flanges 8 and 15 are pierced.

Insulated column works as follows.

5 When assembling a thermally insulated column, sections 1 and 3 (Fig. 1) are interconnected by screwing the flanges 8 and 15 into the mechanical seal 14 until they stop, first installing section 1 with the bell end on the elevator, then installing seal 14, after which sections 1 and 3 are connected to one another by screwing threads 12 and 13 and lower the string into the well. The coolant is served in the internal

5 cavity insulated columns.

Claims (2)

Technical and economic efficiency consists in increasing the heat insulating properties of the thermally insulated pipe string, mainly at the joining points 0 or the double sections between them. Claim 1. Thermally insulated column including pipe sections containing coaxially arranged and forming 5 hermetic annular space, on,. barrel and inner tubes, one of which is prestressed, heat insulating material placed in the annular space between the outer ones 0 and internal pipes, a pipe section assembly with a threaded section on the outer surface of the pipe section of one of its ends and a seal located between the stop surfaces formed by the end flange connecting the external and internal pipes at the end of the section with the external threaded section, and flange at the other end of the pipe section, which is, in order to increase operational reliability by improving the thermal insulation of the joints of the pipe sections into the column, the end of the pipe section opposite to the end with the threaded section on the outer surface, is made in the form of a socket with the threaded section on the inner surface of the pipe section to interact with the threaded section on the outer surface of the other end of the adjacent pipe section, the outer the bell tube is longer than the inner tube length of the bell and forms a gap with the latter, and the difference value of the indicated bell lengths 0 and the gap is equal to the distance between the outer and inner tubes of the column sections, with the flange forming the thrust surface in the socket part of the section located at the base of the socket between the inner tube sections of the main section and the socket part. 2. A column according to claim 1, characterized in that the flanges have liners in the form of crackers from a material with a thermal conductivity lower than the thermal conductivity of the pipe material. / / / VA / 5 21 15 P 23 8 1 S  7 L L Have 1 figs