RU2749686C1 - Device for connecting flanges during well repair - Google Patents

Abstract

FIELD: mining industry.

SUBSTANCE: invention relates to the field of mining, in particular to the oil and gas industry, and can be used in the repair of wells in order to seal the wellhead with the help of flange connections of wellhead equipment. A device for connecting the flanges during well repair is proposed, which contains the support and wellhead flanges tightened together through the combined holes, and an O-ring installed between the flanges in grooves with conical surfaces. In this case, the support and wellhead flanges are tightened together by 4 to 12 retainers. Moreover, each retainer consists of a rod equipped with a thread from the bottom, an eccentric handle pivotally fixed to the upper end of the rod, a support washer and an adjustment nut placed below the support washer and screwed onto the thread of the rod. In the initial position, the locking rods are installed in the combined holes of the support and wellhead flanges, and the adjusting nuts are screwed into the threads of the rods. In this case, the adjusting nuts interact with the lower end of the support flange with their upper ends, and the lower ends of the eccentric handles interact through the support washers with the upper end of the wellhead flange. In the working position, to tighten the support and wellhead flanges together by means of combined holes, the eccentric locking handles are rotated sequentially to the stop of the side ends of the eccentric handles through the support washer into the upper end of the wellhead flange with limited movement of the rods up and sealing the O-ring in the grooves with the conical surfaces of the support and wellhead flanges.

EFFECT: invention can be used in the repair of wells in order to seal the wellhead with the help of flange connections of wellhead equipment. Provided is also an increase in the tightness of the flange connection.

1 cl, 7 dwg

Description

The invention relates to the field of mining, in particular to the oil and gas industry, and can be used when repairing wells in order to seal the wellhead using flange connections of wellhead equipment.

Known flange connections of equipment according to GOST 28919-91 "Types and basic dimensions", containing sealing metal rings in the grooves of the flanges, while the flanges are pulled together by a stud connection.

Also known is the flange connection of parts (patent RU No. 2150041, publ. 05/27/2000), including two flanges tightened together by pins and a sealing element made of a metal ring with two end grooves - grooves for elastic, for example polyurethane, gaskets installed in the chamber formed by circular grooves of a trapezoidal profile on the flanges connected to each other, and the sealing element with its end sections is located in the grooves of the flanges in such a way that half of the end sections, including an elastic gasket protruding from the ring and a part of the ring in the area of the groove, corresponds to their shape, the other half the end sections are made with a gap, and its middle part, connected to the end sections, has a rectangular profile.

The disadvantages of both analogs of the device are:

- low tightness of the flange connection at the wellhead during well workover,

due to uneven tightening of the sealing ring between the wellhead and support flanges due to the fact that the tightening of the stud nuts is performed alternately with different torques;

- the duration of the assembly of the flange connection of the wellhead equipment during well workover, due to the need to seal the wellhead practically after each technological operation (flushing, perforation, etc.), i.e. fix and fasten the wellhead and support flanges with each other using 12 studs and 24 nuts;

- Difficulty in maintenance due to the need to use two wrenches to tighten the studs when attaching the device.

The closest in technical essence and the achieved result is the flange connection of the wellhead equipment, containing the wellhead and support flanges tightened together through the aligned holes, the sealing ring installed between the flanges in grooves with tapered surfaces (patent RU No. 2170807, publ. 20.07.2001). The sealing ring is made of an elastic material with an allowance for deformation, taking into account the presence of an additional ring, and the wellhead and support flanges are pulled together by studs, while the additional ring is made of metal, connected to an elastic material sealing ring and has concentric conical symmetric ribs located on its inner part for centering the grooves in contact with their tapered surfaces, while the outer part of the additional ring is made flat for support outside the grooves of the end surfaces of the flanges and serves as a closing dimensional link in the connection elements.

The disadvantages of the device are:

- low tightness of the flange connection at the wellhead during well workover,

due to uneven tightening of the sealing ring between the wellhead and support flanges due to the fact that the tightening of the stud nuts is carried out alternately with different torques, therefore, to ensure tightness, it is necessary to tighten the loose stud nuts;

- the duration of the assembly of the flange connection of the wellhead equipment during well workover, due to the need to seal the wellhead practically after each technological operation (flushing, perforation, etc.), i.e. fix and fasten the wellhead and support flanges with each other using 12 studs and 24 nuts;

- Difficulty in maintenance due to the need to use two wrenches to tighten the studs when attaching the device.

The technical objectives of the invention are to improve the tightness of the flange connection at the wellhead during well workover, to reduce the duration of the assembly of the flange connection of the wellhead equipment and to simplify the maintenance of the device in operation.

The set technical problems are solved by a device for connecting flanges during well workover, which contains support and wellhead flanges tightened together through aligned holes, a sealing ring installed between the flanges in grooves with tapered surfaces.

What is new is that the support and wellhead flanges are pulled together by clamps, the number of clamps is from 4 to 12, and each clamp consists of a rod equipped with a thread from the bottom, an eccentric handle hinged to the upper end of the rod, a support washer and an adjusting nut located below a support washer and screwed onto the stem thread, while in the initial position the retainer rods are installed in the combined holes of the support and wellhead flanges, and the adjusting nuts are screwed into the threads of the rods, while the adjusting nuts with their upper ends interact with the lower end of the support flange, and the lower ends of the eccentric handles interact through support washers with the upper end of the wellhead flange, while in the working position to tighten the support and wellhead flanges together by means of aligned holes, the eccentric handles of the latches are sequentially turned until the lateral ends of the eccentric handles stop through the support washers into the upper end of the wellhead flange with limited upward movement of the rods and sealing of the O-ring in the grooves with tapered surfaces of the support and wellhead flanges.

FIG. 1 schematically shows a device for connecting flanges during well workover.

FIG. 2 schematically shows an enlarged view A of the device for connecting flanges during well workover in the initial position.

FIG. 3 schematically shows view B of the device for connecting flanges during well workover in the initial position.

FIG. 4 schematically shows an enlarged view A of a device for connecting flanges during well workover in working position.

FIG. 5 schematically shows view B of a device for connecting flanges during well workover in working position.

FIG. 6 is a schematic view B of a device for connecting flanges during well workover.

FIG. 7 schematically shows a view C of a device for connecting flanges during well workover.

The device for connecting flanges during well workover contains tightened between each other through the aligned holes support 1 (see Fig. 1-5, 7) and wellhead 2 (see Fig. 1-6) flanges installed between the flanges in grooves with tapered surfaces ring 3 (see Figs. 1-2, 4).

Support 1 and wellhead 2 flanges are pulled together through holes 4 (see Fig. 1-2, 4) by clamps 5 (see Fig. 2-6), and the number of clamps from 4 to 12 is determined empirically in order to ensure the tightness of the flange connections depending on the hydraulic pressure perceived by the flange connection. The number of retainers is not more than the number of combined holes of the support 1 and wellhead 2 flanges, but not less than four in order to uniformly cover the perimeter of the support 1 (see Figs. 1 and 4) and wellhead 2 flanges and ensure the tightness of the sealing ring 3 at minimum pressure, for example 3.0 MPa. It has been experimentally established that the maximum number of aligned holes of the support 1 and wellhead 2 flanges is 12, at the maximum pressure perceived by the flange connection, for example 35.0 MPa. Let's take the number of aligned holes of the reference 1 and wellhead 2 flanges equal to 8: 4 ¹ ; 4 ² ; 4 ³ ; 4 ⁴ ; 4 ⁵ ; 4 ⁶ ; 4 ⁷ ; 4 ⁸ .

The outer diameters (D _f ) of the support 1 and wellhead 2 flanges are equal to each other and, for example, are equal to D _f = 300 mm. Since the number of aligned flange holes is 8, the central angle is α between aligned holes 4 ¹ ; 4 ² ; 4 ³ ; 4 ⁴ ; 4 ⁵ ; 4 ⁶ ; 4 ⁷ ; 4 ⁸ support 1 and wellhead 2 flanges is equal to: α = 360 ° / 8 = 45 °.

Each retainer 5 ¹ ; 5 ² ; 5 ³ ; 5 ⁴ ; 5 ⁵ ; 5 ⁶ ; 5 ⁷ ; 5 ^8, respectively, consists of a rod 6 ¹ ; 6 ² ; 6 ³ ; 6 ⁴ ; 6 ⁵ ; 6 ⁶ ; 6 ⁷ ; 6 ⁸ (see Fig. 2-5, 7), equipped with a bottom thread 7 ¹ ; 7 ² ; 7 ³ ; 7 ⁴ ; 7 ⁵ ; 7 ⁶ ; 7 ⁷ ; 7 ⁸ , eccentric handle 8 ¹ ; 8 ² ; 8 ³ ; 8 ⁴ ; 8 ⁵ ; 8 ⁶ ; 8 ⁷ ; 8 ⁸ (see Fig. 2-6) pivotally, for example, using a pin 9 (see Fig. 2-5), fixed to the upper end of the rod 6 ¹ ; 6 ² ; 6 ³ ; 6 ⁴ ; 6 ⁵ ; 6 ⁶ ; 6 ⁷ ; 6 ⁸ , support washer 10 ¹ ; 10 ² ; 10 ³ ; 10 ⁴ ; 10 ⁵ ; 10 ⁶ ; 10 ⁷ ; 10 ⁸ (see Fig. 2-6) and an adjusting nut 11 ¹ ; 11 ² ; 11 ³ ; 11 ⁴ ; 11 ⁵ ; 11 ⁶ ; 11 ⁷ ; 11 ⁸ (see Figs. 2-5, 7).

Adjusting nut 11 ¹ ; 11 ² ; 11 ³ ; 11 ⁴ ; 11 ⁵ ; 11 ⁶ ; 11 ⁷ ; 11 ^{8 is} located below the corresponding support washer 10 ¹ ; 10 ² ; 10 ³ ; 10 ⁴ ; 10 ⁵ ; 10 ⁶ ; 10 ⁷ ; 10 ⁸ . Adjusting nut 11 ¹ ; 11 ² ; 11 ³ ; 11 ⁴ ; 11 ⁵ ; 11 ⁶ ; 11 ⁷ ; 11 ^{8 is} screwed into the corresponding thread 7 ¹ ; 7 ² ; 7 ³ ; 7 ⁴ ; 7 ⁵ ; 7 ⁶ ; 7 ⁷ ; 7 ⁸ stem 6 ¹ ; 6 ² ; 6 ³ ; 6 ⁴ ; 6 ⁵ ; 6 ⁶ ; 6 ⁷ ; 6 ⁸ .

In the initial position, the rods are 6 ¹ ; 6 ² ; 6 ³ ; 6 ⁴ ; 6 ⁵ ; 6 ⁶ ; 6 ⁷ ; 6 ⁸ clips 5 ¹ ; 5 ² ; 5 ³ ; 5 ⁴ ; 5 ⁵ ; 5 ⁶ ; 5 ⁷ ; 5 ⁸ installed in aligned holes 4 ¹ ; 4 ² ; 4 ³ ; 4 ⁴ ; 4 ⁵ ; 4 ⁶ ; 4 ⁷ ; 4 ⁸ support 1 and wellhead 2 flanges, and adjusting nuts 11 ¹ ; 11 ² ; 11 ³ ; 11 ⁴ ; 11 ⁵ ; 11 ⁶ ; 11 ⁷ ; 11 ⁸ screwed into threads 7 ¹ ; 7 ² ; 7 ³ ; 7 ⁴ ; 7 ⁵ ; 7 ⁶ ; 7 ⁷ ; 7 ⁸ corresponding rods 6 ¹ ; 6 ² ; 6 ³ ; 6 ⁴ ; 6 ⁵ ; 6 ⁶ ; 6 ⁷ ; 6 ⁸ .

Adjusting nuts 11 ¹ ; 11 ² ; 11 ³ ; 11 ⁴ ; 11 ⁵ ; 11 ⁶ ; 11 ⁷ ; 11 ⁸ upper ends interact with the lower end of the support flange 1, and the lower ends 12 ¹ ; 12 ² ; 12 ³ ; 12 ⁴ ; 12 ⁵ ; 12 ⁶ ; 12 ⁷ ; 12 ⁸ (see Fig. 2-3) of the corresponding eccentric handles 8 ¹ ; 8 ² ; 8 ³ ; 8 ⁴ ; 8 ⁵ ; 8 ⁶ ; 8 ⁷ ; 8 ⁸ interact through support washers 10 ¹ ; 10 ² ; 10 ³ ; 10 ⁴ ; 10 ⁵ ; 10 ⁶ ; 10 ⁷ ; 10 ⁸ with the upper end of the wellhead flange 2.

In the working position for tightening the support 1 and wellhead 2 flanges together by means of aligned holes 4 ¹ ; 4 ² ; 4 ³ ; 4 ⁴ ; 4 ⁵ ; 4 ⁶ ; 4 ⁷ ; 4 ⁸ sequentially turn the eccentric handles 8 ¹ ; 8 ² ; 8 ³ ; 8 ⁴ ; 8 ⁵ ; 8 ⁶ ; 8 ⁷ ; 8 ⁸ clips 5 ¹ ; 5 ² ; 5 ³ ; 5 ⁴ ; 5 ⁵ ; 5 ⁶ ; 5 ⁷ ; 5 ⁸ up to the stop of the side ends 13 ¹ ; 13 ² ; 13 ³ ; 13 ⁴ ; 13 ⁵ ; 13 ⁶ ; 13 ⁷ ; 13 ⁸ (see Fig. 4-5) of the corresponding eccentric handles 8 ¹ ; 8 ² ; 8 ³ ; 8 ⁴ ; 8 ⁵ ; 8 ⁶ ; 8 ⁷ ; 8 ⁸ through the support washer into the upper end of the wellhead flange 2 with limited movement of the rods 6 ¹ ; 6 ² ; 6 ³ ; 6 ⁴ ; 6 ⁵ ; 6 ⁶ ; 6 ⁷ ; 6 ⁸ upwards and sealing the sealing ring 3 in the grooves with tapered surfaces of the support 1 and wellhead 2 flanges.

When the device operates, the following equality is fulfilled:

where a_one - but₂ = c - b = ∆,

a ₁ - the gap between the support 1 and the wellhead 2 flanges (see Fig. 2 and 3) in the initial position, mm; a ₂ - the gap between the support 1 and the wellhead 2 flanges (see Fig. 4 and 5) in the working position, mm;

c - distance from the central axis of each of the eccentric handle 8 ¹ ; 8 ² ; 8 ³ ; 8 ⁴ ; 8 ⁵ ; 8 ⁶ ; 8 ⁷ ; 8 ⁸ to their side end 13 (see Fig. 5), mm;

b is the distance from the central axis of each of the eccentric handle 8 ¹ ; 8 ² ; 8 ³ ; 8 ⁴ ; 8 ⁵ ; 8 ⁶ ; 8 ⁷ ; 8 ⁸ to their lower end 12 (see Fig. 3), mm;

∆ is the difference by the amount of which the stocks move up 6 ¹ ; 6 ² ; 6 ³ ; 6 ⁴ ; 6 ⁵ ; 6 ⁶ ; 6 ⁷ ; 6 ⁸ , mm or the support 1 and wellhead 2 flanges are pulled together, mm.

For example, let's take c = 18 mm, b = 13 mm, and ₁ = 15 mm; a ₂ = 10 mm.

Then ∆ = 18 mm - 13mm = 15 mm - 10 mm = 5 mm.

The device works as follows.

In the groove (in Figs. 1, 2 and 4 it is shown conditionally) with the tapered surface of the support flange 1 (see Fig. 1, 2, 4) an O-ring 3 is installed. Then the wellhead flange 2 is installed on top of the O-ring 3 with a groove with a tapered surface ...

By rotation of the wellhead flange 2 relative to the support flange 1, 8 holes 4 ¹ are aligned with each other, as indicated above; 4 ² ; 4 ³ ; 4 ⁴ ; 4 ⁵ ; 4 ⁶ ; 4 ⁷ ; 4 ⁸ support 1 and wellhead 2 flanges.

Further, the retainers 5 ¹ are inserted in turn; 5 ² ; 5 ³ ; 5 ⁴ ; 5 ⁵ ; 5 ⁶ ; 5 ⁷ ; 5 ⁸ (see Fig. 1 - 6) in the corresponding aligned holes 4 ¹ ; 4 ² ; 4 ³ ; 4 ⁴ ; 4 ⁵ ; 4 ⁶ ; 4 ⁷ ; 4 ⁸ support 1 and wellhead 2 flanges.

Next, the device is brought to its original position. To do this, screw in the adjusting nuts 11 ^{1 one by one} ; 11 ² ; 11 ³ ; 11 ⁴ ; 11 ⁵ ; 11 ⁶ ; 11 ⁷ ; 11 ⁸ (see Fig. 2 and 3) on the threads 7 ¹ ; 7 ² ; 7 ³ ; 7 ⁴ ; 7 ⁵ ; 7 ⁶ ; 7 ⁷ ; 7 ⁸ corresponding rods 6 ¹ ; 6 ² ; 6 ³ ; 6 ⁴ ; 6 ⁵ ; 6 ⁶ ; 6 ⁷ ; 6 ⁸ up to the stop of the upper ends of the nuts 11 ¹ ; 11 ² ; 11 ³ ; 11 ⁴ ; 11 ⁵ ; 11 ⁶ ; 11 ⁷ ; 11 ⁸ into the lower end of the support flange 1, while the lower ends 12 ¹ ; 12 ² ; 12 ³ ; 12 ⁴ ; 12 ⁵ ; 12 ⁶ ; 12 ⁷ ; 12 ⁸ corresponding eccentric handles 8 ¹ ; 8 ² ; 8 ³ ; 8 ⁴ ; 8 ⁵ ; 8 ⁶ , 8 ⁷ ; 8 ⁸ through the corresponding support washers 10 ¹ ; 10 ² ; 10 ³ ; 10 ⁴ ; 10 ⁵ ; 10 ⁶ ; 10 ⁷ ; 10 ⁸ are pressed against the upper end of the wellhead flange 2. Thus, the device is in its original position.

Next, the device is brought into working position. For this, the eccentric handles 8 ^{1 are} alternately turned; 8 ² ; 8 ³ ; 8 ⁴ ; 8 ⁵ ; 8 ⁶ ; 8 ⁷ ; 8 ⁸ (see Fig. 4 and 5) of the corresponding retainers 5 ¹ ; 5 ² ; 5 ³ ; 5 ⁴ ; 5 ⁵ ; 5 ⁶ ; 5 ⁷ ; 5 ⁸ , for example at an angle of 90 °. As a result, each of the rods 6 ¹ ; 6 ² ; 6 ³ ; 6 ⁴ ; 6 ⁵ ; 6 ⁶ ; 6 ⁷ ; 6 ⁸ corresponding clips 5 ¹ ; 5 ² ; 5 ³ ; 5 ⁴ ; 5 ⁵ ; 5 ⁶ ; 5 ⁷ ; 5 ⁸ moves up as indicated above by the value ∆ = c - b = 5 mm, while the support 1 and wellhead 2 flanges are pulled together, compressing the O-ring 3 in the grooves of the support 1 and wellhead 2 flanges (clearance a ₁ = 15 mm ( in the initial position) between the support 1 and the wellhead 2 flange is reduced to a ₂ = 10 mm (in the working position) due to the movement of the rods 6 ¹ ; 6 ² ; 6 ³ ; 6 ⁴ ; 6 ⁵ ; 6 ⁶ ; 6 ⁷ ; 6 ⁸ corresponding latches 5 ¹ ; 5 ² ; 5 ³ ; 5 ⁴ ; 5 ⁵ ; 5 ⁶ ; 5 ⁷ ; 5 ⁸ upwards by 5 mm. Thus, the device takes the working position

Support 1 and wellhead 2 (see Fig. 1) flanges are hermetically connected to each other. Further, a technological operation is carried out to repair the well, for example, the well is flushed. After the completion of the technological operation for the well workover, disassembly is performed in the reverse order.

The tightness of the connection of the support 1 and wellhead 2 flanges increases with each other during well workover due to the fact that all adjusting nuts 11 ¹ ; 11 ² ; 11 ³ ; 11 ⁴ ; 11 ⁵ ; 11 ⁶ ; 11 ⁷ ; 11 ⁸ (see Fig. 2-5 7) on the threads 7 ¹ ; 7 ² ; 7 ³ ; 7 ⁴ ; 7 ⁵ ; 7 ⁶ ; 7 ⁷ ; 7 ⁸ corresponding rods 6 ¹ ; 6 ² ; 6 ³ ; 6 ⁴ ; 6 ⁵ ; 6 ⁶ ; 6 ⁷ ; 6 ^{8 are} first screwed in alternately and evenly (for example, by 5 turns) and manually up to the stop of the upper ends of the adjusting nuts 11 ¹ ; 11 ² ; 11 ³ ; 11 ⁴ ; 11 ⁵ ; 11 ⁶ ; 11 ⁷ ; 11 ⁸ into the lower end of the support flange 1, and then by alternately turning the eccentric handles 8 ¹ ; 8 ² ; 8 ³ ; 8 ⁴ ; 8 ⁵ ; 8 ⁶ ; 8 ⁷ ; 8 ⁸ (see Fig. 2-6) of the corresponding retainers 5 ¹ ; 5 ² ; 5 ³ ; 5 ⁴ ; 5 ⁵ ; 5 ⁶ ; 5 ⁷ ; 5 ^{8 the} device is sealed, which ensures uniform contraction of the support 1 and wellhead 2 flanges.

Due to the tightening of the support 1 and the wellhead 2 flanges by alternately turning the eccentric handles 8 ¹ ; 8 ² ; 8 ³ ; 8 ⁴ ; 8 ⁵ ; 8 ⁶ ; 8 ⁷ ; 8 ⁸ (see Fig. 4 and 5) of the corresponding retainers 5 ¹ ; 5 ² ; 5 ³ ; 5 ⁴ ; 5 ⁵ ; 5 ⁶ ; 5 ⁷ ; 5 ⁸ , the duration of the assembly of the flange connection of the wellhead equipment is reduced by 3-4 times during the workover of the well for the technological operation (flushing, perforation, etc.), while eliminating the need for screwing and tightening on the studs using two wrenches 24 nuts, as in the prototype.

The presence of eccentric handles 8 ¹ ; 8 ² ; 8 ³ ; 8 ⁴ ; 8 ⁵ ; 8 ⁶ ; 8 ⁷ ; 8 ⁸ corresponding clips 5 ¹ ; 5 ² ; 5 ³ ; 5 ⁴ ; 5 ⁵ ; 5 ⁶ ; 5 ⁷ ; 5 ⁸ eliminates the need to use wrenches to tighten the nuts when tightening the support 1 and wellhead 2 flanges, which simplifies the maintenance of the device in operation. The proposed device for connecting flanges during well workover allows:

- to improve the tightness of the flange connection at the wellhead during well workover;

- reduce the time required to assemble the support flanges at the wellhead;

- to simplify the maintenance of the device in operation.

Claims (1)

A device for connecting flanges during well workover, containing support and wellhead flanges tightened together through aligned holes, an O-ring installed between the flanges in grooves with tapered surfaces, characterized in that the support and wellhead flanges are pulled together by clamps, the number of clamps is from 4 to 12, and each retainer consists of a rod equipped with a bottom thread, an eccentric handle pivotally attached to the upper end of the rod, a support washer and an adjusting nut located below the support washer and screwed onto the stem thread, while in the initial position the retainer rods are installed in the aligned holes the support and wellhead flanges, and the adjusting nuts are screwed into the threads of the rods, while the adjusting nuts with the upper ends interact with the lower end of the support flange, and the lower ends of the eccentric handles interact through the support washers with the upper end of the wellhead flange, while in the working position for tightening the support The eccentric handles of the latches are sequentially rotated between the mouth and wellhead flanges through the aligned holes until the side ends of the eccentric handles stop through the support washer into the upper end of the wellhead flange with limited upward movement of the rods and sealing the sealing ring in the grooves with tapered surfaces of the support and wellhead flanges.

Images