RU2566520C1 - Method for restoring service properties of tubing string by linering - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method for restoring service properties of tubing string by linering is suggested with included radiation control of the tubing string, cleanout of outer and inner surface of tubing from deposits and impurities, introduction of thin-wall corrosion-resistant electrically welded liner pipe into tubing string channel with adhesive sealant applied preliminary to outer surface of the liner pipe, joint deformation of the tubing string and liner pipe by drifting, cutting of the lined ends of the tubing string, threading at tube ends, screwing of sleeves, hydraulic testing of tubes and control with instruments. At that operations of accuracy increase are performed for inner channel of the tubing string by changing inner diameter of tubes and their sorting into two-three groups by diameters as well as calibration of inner channel of the tubing string by passing deformation bend former of the preset size through it.

EFFECT: reduced consumption of material resources and improved efficiency due to increased accuracy of the tubing string inner diameter.

Description

The present invention relates to the field of restoration of service properties of metal products (products from ferrous metals) that have completely exhausted service properties at the first stage of their operation, namely, the technique and technology for restoration of service properties of used tubing pipes (tubing used). Tubing pipes (tubing) are mainly used as a means of extracting (producing) oil or natural gas from oil and gas fields to the surface of the earth to field pipelines. Recoverable products (a mixture of oil, produced water, natural or associated gas, etc.) contain corrosive elements - hydrogen sulfide, carbon dioxide, components of biological corrosion, etc. Under the influence of mechanical stresses and corrosion processes, tubing wears out and in case of wear of the pipe wall thickness more than 25-30% of the nominal value of the wall of the new pipe pipes are decommissioned and must be repaired.

The closest solution to the claimed method, which was adopted as a prototype and which reflects the prior art in the field of repair and restoration of service properties of tubing used, is a method of repair of tubing, the technology of which is described in Patent No. 2338053 of 02/08/2007 The indicated tubing repair technology includes the following main technological operations: radiation control of the tubing, cleaning of the outer and inner surfaces of the pipes from deposits and contaminants, the introduction of thin-walled corrosion-resistant with a straight welded pipe-liner into the tubing channel, with pre-applied adhesive-sealant on the outer surface of the liner, joint deformation of the tubing and the liner by distribution, trimming the ends of the lined tubing, threading at the ends of the pipes, tightening the couplings, hydraulic pipe testing, visual and instrument control.

Reconstructed tubing possesses improved operational properties (corrosion resistance, operational reliability, etc.) compared to new pipes, which is confirmed by the operation of lined tubing for 5 years in the oil fields of OAO Tatneft in production and injection wells and in the high pressure pipeline water into the injection well.

Disclosure of invention

The disadvantage of the tubing lining technology described in the prototype is the lack of controllability of the lining process, which is expressed in the uncontrolled extension of the liner in the process of joint deformation of the tubing and the liner distribution. Uncontrolled extension of the liner is inevitable due to insufficient initial accuracy of the inner diameters of the tubing, expressed by the range of variation in the values of the inner diameters ΔD. When the liner is distributed together with tubing having a range of variation in ΔD values, the liners of the same size are subjected to different degrees of deformation, which leads to their different elongation.

New tubing is manufactured according to generally recognized standards (GOST R 52203-2004, the standards of the American Petroleum Institute API-5CT, etc.), which establish the quality and size of pipes. Manufactured tubing must comply with the technical requirements of these standards. Due to certain technological conditions for the manufacture of new pipes, the standards provide for tolerances from the nominal dimensions of both the outer and inner diameters and the wall thickness of the pipes.

Studies of the quality of new and used tubing, performed by the authors of the invention, the following is established.

Example 1. 850 pipes with nominal dimensions of 73 × 5.5 mm were selected from the tubing maintenance fund and their outer diameters and wall thicknesses were measured. As a result of measurements of these parameters, it was found that the outer diameters of the pipes vary from 72.2 mm to 73.8 mm, and wall thicknesses from 4.8 mm to 5.8 mm, which fully meets the requirements of the standards. The inner diameter of the pipes varies over a wider range, since its deviations are affected by the actual deviations, both in the outer diameter of the pipes and in the wall thickness. The minimum and maximum deviations of the inner diameter of the pipes are expressed by the formulas:

Dвн max = Dнар max-2Smin,

Dвн min = Dнар min-2Smax,

where Dвн max, Dвн min - maximum and minimum internal diameters of pipes;

Dнар max, Днар min - maximum and minimum outer diameters of pipes,

Smax, Smin - maximum and minimum pipe wall thicknesses.

The actual dimensions of the inner diameters of the studied tubing vary from 60.4 mm to 64.2 mm. The range of variation in the values of the inner diameters ΔD of the pipes is 3.8 mm, which also meets the standards for the manufacture of tubing.

According to the conditions of unhindered introduction of the liner into the tubing channel up to 10 m long, it is required that the liner outer diameter be 3-4 mm less than the minimum value of the tubing internal diameter, taking into account the tolerances. For the case under consideration, the outer diameter of the liner should not exceed 57 mm. Therefore, the gaps between the outer diameter of the liner and the inner diameter of the tubing are: minimum - 60.6-57 = 3.4 mm, and maximum - 64.2-57 = 7.2 mm. Actual clearances between pipes varying within the indicated limits are not known in advance. This complicates the management of the processes of joint deformation of liners and tubing, the selection of tools (mandrels) for joint deformation of pipes (distribution) so that the final clearance between the pipes (after distribution) is in the range from 0.0 mm to 0.2 mm ( on the side), which follows from the conditions for bonding tubing and liners. The issues of choosing the optimal size (length) of the liner also remain uncertain for the following reasons.

During joint deformation of pipes at the first stage of the process (when pulling the mandrel through the liner channel), its diameter increases until it contacts the inner surface of the tubing, i.e. from 3.4 mm to 7.2 mm. In this case, the liner wall thickness is preserved, and its length decreases inversely with the increase in diameter, i.e. shortened by 600-1200 mm.

At the second stage of pipe distribution, a slight increase in their diameters (up to 0.3 mm) and thinning of the liner wall occur. With a nominal thickness of 1.5 mm, wall thinning by 0.1 mm is 7.5%. The extension of the liner will take exactly the same amount, i.e. by 750 mm (with its nominal length of 10,000 mm).

The technologically caused inevitability of uncontrolled, then shortening, or lengthening of the liner, caused by the inconsistency of the inner diameters of the tubing, makes the lane process difficult to control, which inevitably leads to increased material costs in the form of cut ends of the liners or tubing, as well as a decrease in the productivity of the lane tubing process as a whole.

It is possible to improve the controllability of the tubing lining process, reduce the costs of material resources and increase its productivity if the accuracy of the tubing channels is increased and their deviations between the minimum and maximum values are reduced.

The objective of the claimed technical solution of the invention is to develop a method for improving the accuracy of the inner diameter of the tubing in the initial state - before lane.

The implementation of the invention.

The claimed technical result is achieved by the fact that in the technology of restoration of service properties of tubing by lining, including radiation monitoring of the tubing, cleaning the outer and inner surfaces of the pipes from deposits and contaminants, the introduction of a thin-walled corrosion-resistant electric-welded pipe-liner into the tubing channel, with previously applied glue-sealant on the outer surface of the liner, the joint deformation of the tubing and the liner by hand, trimming the ends of the lined tubing, threading at the ends of the pipes, probably coupling webs, hydraulic pipe testing, visual and instrument control, according to the invention, additional technological operations are introduced, namely: after cleaning the inner surface of the tubing from deposits and contaminants, the following is carried out: the inner diameter of each pipe is measured and the pipes are sorted into two or three lots, and then calibrate the channels of each tubing by pulling through the channels of the pipes of the deforming mandrel with predetermined sizes.

Measuring the inner diameters of pipes and sorting them into three groups ensures a threefold reduction in the range of sizes of internal diameters — from 3.8 mm to 1.3 mm in each group of pipes, and calibration of tubing channels by pulling mandrels with predetermined dimensions through them ensures a decrease in the range of variation in the values of the inner diameters ΔD of the tubing by at least 3 times. This makes it possible to reduce the spread in the values of the degrees of deformation of the liner during joint distribution with tubing and, therefore, the spread in the values of its elongation.

The technical result is achieved, firstly, by measuring the actual dimensions of the channel of each tubing and sorting the pipes into two or three lots, and secondly, by calibrating the tubing channels after sorting by internal diameters (before laning) by pulling through the tubing channels mandrels with predetermined dimensions .

Example 2. The selection of tubing used with an inner diameter of 60.4 mm to 62.3 mm. A mandrel with a diameter of 62.3 mm was pulled through the tubing channels. Measurement of the inner diameters of the tubing after calibration revealed that the maximum inner diameter of the tubing is 62.3 mm and the minimum is 61.7 mm. The total variation in the values of the tubing channel diameters was 0.6 mm instead of 3.8 mm in the initial state of new tubing.

Measuring the diameter of the tubing channels, sorting them by diameters in conjunction with calibrating the tubing channels, reduces the difference in the diameters of the channels between their minimum and maximum values from 3.8 mm (initial value) to 0.6 mm (after sorting the pipes and calibrating the channels), t .e. more than 6 times. Accordingly, the shortening of the liners during their distribution is reduced by the same amount, which improves the controllability of the tubing lining processes and reduces the consumption of the liners in the form of a technologically inevitable trim. The maximum decrease in the length of the liners during their distribution will be about one percent, which is about 100 mm with the initial length of the liner 10,000 mm, which is quite acceptable for industrial technologies.

Based on the foregoing, the technology of lining of tubing must be carried out in the following sequence:

- after radiation control of the tubing, cleaning of the outer and inner surface of the tubing from deposits and contaminants, visual and instrumental quality control of pipes provided by the well-known technology of pipe lining (patent No. 2338053), additional technological operations are carried out - measuring the internal channels of the pipes and sorting them into two or three batches, and then calibrate the internal channels of each tubing, which is achieved by pulling through the channels of the mandrel tubes with specified sizes.

After performing these additional operations, the remaining technological operations are provided for by patent No. 2338053:

- introduction of a thin-walled corrosion-resistant electric-welded pipe-liner into the tubing channel, with previously applied adhesive-sealant on the outer surface of the liner;

- joint deformation of tubing and liner distribution;

- trimming the ends of the lined tubing;

- threading at the ends of the pipes;

- winding couplings;

- hydraulic pipe test;

- visual and instrument control.

Claims (1)

A method of restoring the service properties of tubing by lining, including radiation monitoring of the tubing, cleaning the outer and inner surfaces of the pipes from deposits and contaminants, introducing a thin-walled corrosion-resistant electric-welded pipe-liner into the tubing channel, with pre-applied adhesive sealant on the outer surface of the liner, joint deformation of the tubing and the liner by distribution, trimming the ends of the lined tubing, threading at the ends of the pipes, winding the couplings, hydraulic testing of pipes, visual and instrument control, characterized in that in order to create conditions for the controllability of the lining process, to reduce the costs of lining and to increase the productivity of the process, operations are carried out to increase the accuracy of the inner tubing channel by measuring the inner diameter of the pipes and sorting them into two or three groups by diameter, as well as calibrating the inner channel Tubing by pulling through it a deformation mandrel of a predetermined size.