RU2616647C1 - Kelly sealant on wellhead with perception of reactive torque from turbodrill rotation - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to equipment for wellhead sealing during drilling by turbine method. The device comprises a housing with an upper base and a lower flange. The through axial passage of the housing has an insert. The insert comrpises a sealing unit consisting of a clamp, a support, and a sealing cup between them, all are joined by studs and nuts. The insert consists of two halves with diametrical slot, which are pivotally joined to each other, and in the closed position are fixed with the latch. The clamp, the support and the cup have a central square hole. The insert fixing assembly in the housing is designed as movable slides with a screw drive arranged in upper radial holes in the base. The insert fixing assembly (to avoid rotation in the housing) is implemented in the form of two support shoulders arranged on the conical clamping surface and interacting with the sliders. The upper base of the housing is designed as a flange with holes for studs and with the circular groove for the sealing ring.

EFFECT: invention provides improved reliability, safety and ease of use, decreased complexity and time-consumption, as well as increased operational capabilities.

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Description

The invention relates to equipment for sealing a wellhead during turbine drilling.

A wellhead sealing device is known (RF patent No. 2272123, IPC ЕВВ 33/03, publ. March 20, 2006), containing:

- a housing with a Central through-channel conical shape for the passage of pipes containing upper and lower flanges,

- plug-in sealant, consisting of two halves with a diametrical connector and containing the upper and lower disks connected by screw connection to the compression nut, between which there is a sealing element having a through longitudinal hole,

- the fixation unit of the plug-in sealant in the housing, made in the form of movable cylinders with a screw drive, located in the radial holes of the upper flange of the housing.

A disadvantage of the known device is the limited operational capabilities that do not allow it to be used when conducting drilling operations using a turbodrill. This is due to the fact that the turbine method of drilling involves the use of a square leading pipe held by the rotor to receive the reactive moment from the turbodrill through the drill pipe string, and the known device, which is intended only for sealing cylindrical pipes with a cable, does not provide for holding the leading pipe from rotation nor sealing its square section at the wellhead.

Known sealant wellhead and an insert for perceiving the reactive moment of the lead pipe and transmitting it to the base of the wellhead with simultaneous sealing of the wellhead (PM RF No. 68053, IPC EV 33/03, publ. 10.11.2007), containing:

- a sealant body, with an upper base and a lower flange, in which a through axial channel for passing pipes is made, the middle section of the through axial channel having the shape of a round truncated cone, expanding upwards,

- an insert containing a hollow body, the lower part of which interacts with the conical section of the through axial channel of the housing of the sealant, and the upper part is located above the upper base and is equipped with a clamping nut, and a step is made in the cylindrical bore of the cavity of the upper part of the insert body,

- while the lower part of the insert body on the outside has the shape of a round truncated cone, expanding upwards, and is equipped with an elastic ring seal,

- and in the cavity of the upper part of the insert body on the ledge, a sealing block is installed, consisting of two halves with a diametrical connector and including a cylindrical support connected by means of couplers with nuts and a clamp interacting with the clamping nut,

- between the support and the clamp is located a sealing cuff made in the form of a cylinder, while in the clamp, support and sealing cuff an axial square hole is made,

- the unit for fixing the sealing block from turning in the insert body is made in the form of protrusions located on the lower end of the support and interacting with mating grooves made in a ledge in the cavity in the upper part of the insert body,

- insert fixation unit in the sealant housing is made in the form of movable sliders with manual screw drives located in radial holes of the upper base and interacting with an annular groove made on the outer surface of the upper part of the insert housing.

A disadvantage of the known device is the complexity and the risk of its installation and preparation for operation, involving the following operations:

- before starting drilling operations and during their implementation after each drilling cycle, it is necessary to dismantle the insert from the through axial channel of the sealant body to install a slider with a drill pipe suspended on it, with which the lead pipe should be screwed, due to the location of the insert body above the upper base;

- disassembling the insert before starting work to install it on the lead pipe;

- installing the insert body with the lower part in the conical section of the through axial channel of the sealant body;

- pre-screwing the clamping nut onto the top of the insert body;

- the input of the lead pipe suspended on the hook block at first into the passage hole of the clamping nut, and then the insert body;

- screwing the clamping nut from the upper part of the insert body, lifting and holding the clamping nut in a raised position;

- assembly and installation around the lead pipe of the halves of the sealing block, including the support, the sealing collar, the clamp and the couplers connecting them to the nuts;

- installation of the halves of the sealing block in the cavity of the upper part of the insert body with the alignment of the projections of the support with the reciprocal grooves of the ledge;

- final make-up of the clamping nut with the upper part of the insert body before interacting with the clamp.

The operation of introducing the lead pipe suspended on the hook block into the bore of the insert body with the clamping nut, due to the insignificant difference in the diameter of its hole with the diameter of the lower sub of the lead pipe, requires manual holding and centering of the lead pipe in order to maintain alignment of its longitudinal axis with the center of the bore of the insert body, which is laborious and unsafe for maintenance personnel when swinging the lead pipe with swivel and hook block from wind load, resulting in increased risk of injury s operation known dock. In addition, the implementation of the complex of these operations requires a significant investment of time, and the performance of such operations as holding the insert body and the clamping nut on the lead pipe while installing the halves of the sealing block in the cavity of the upper part of the insert body with the alignment of the projections of the support with the reciprocal grooves of the step and subsequent screwing clamping nut requires additional staff.

Another disadvantage of the known sealant is the inoperability of its reconfiguration for the next cycle of drilling operations. This is due to the fact that for the next sealing cycle, the insert must be moved along the lead pipe to its original position above the lower sub, and this cannot be done quickly manually, since the sealing sleeve on the lead pipe is clamped between the support and the clamp. Therefore, to move the insert of the known device along the lead pipe, it is first necessary to loosen the screed of the sealing collar of the sealing block until a gap appears between the sealing surfaces. But since the square surfaces of the lead pipe cannot be smooth, because they will inevitably have scuffs and scratches with a high height of roughness peaks due to interaction with the dies of the key or rotor, the working surfaces of the sealing collar, even if there is a gap, will inevitably be subject to wear due to scoring and scratches of the lead pipe when moving the insert along the lead pipe, which will result accelerated wear of the sealing collar, its inoperability and the need for replacement. To completely eliminate wear on the working surfaces of the sealing collar when moving along the lead pipe, the insert must be disassembled to remove the sealing block, but this will significantly increase the downtime of the drilling process, which, in turn, can lead to an accident, as a stationary drill string suspended on slider wedges can be caught in the well during idle time in order to carry out these operations.

The disadvantages of the known sealant also include the low reliability of the performance of operational functions due to the fact that the transmission of torque from the insert body to the sealant body is carried out only due to friction forces. This is due to the design of the sealant, in which the groove for the access of the sliders in the insert body is made annular, as a result of which the force of fixing the insert body against rotation relative to the case of the sealant will be determined only by the friction force arising from the interaction of the surfaces of the sliders and the annular groove, which may not be sufficient for reliable fixation from turning the insert body in the sealant body.

In addition, the known sealant has limited operational capabilities due to the fact that it is impossible to install additional sealing equipment on the upper base of the sealant case, since the upper base is solid, has no holes for studs and grooves for the sealing ring, and also because the upper part of the housing the insert is located above the surface of the upper base of the sealant housing and its outer dimensions both in diameter and in height may not allow becoming any additional sealing equipment having the orifice diameter smaller than the outer diameter of the upper part of the insert body. The inability to install such additional sealing equipment at the beginning of oil and gas development due to leakage of the mouth can lead to an open fountain, the elimination of which will require significant costs.

The combination of these circumstances reduces the convenience, reliability and safety, increases the complexity and time costs during operation, and also limits the operational capabilities of the well-known sealant wellhead.

The objective of the invention is to provide a technical solution for the sealing of the lead pipe at the wellhead, devoid of the above disadvantages.

The technical result of solving this problem is to increase the reliability, safety and ease of operation, expanding operational capabilities, as well as reducing the complexity and time costs when using a wellhead sealant.

To ensure this result, the known lead pipe sealant at the wellhead with the perception of the reactive moment from the rotation of the turbodrill, containing:

- a housing with an upper base and a lower flange in which a through axial channel for passing pipes is made, the lower portion of which under the upper base has the shape of a round truncated cone, expanding upwards,

- an insert installed in the through axial channel of the housing in the form of a sealing block consisting of two halves with a diametrical connector and containing a clamp, a support and a sealing collar located between them, connected by means of studs and nuts,

- moreover, in the clamp, support and sealing cuff, a central square hole is made, and the outer surface of the cuff is conical and interacts with the conical surface of the through axial channel of the housing,

- node fixing the insert in the housing, made in the form of movable sliders with a screw drive, located in the radial holes of the upper base and interacting with the insert without the possibility of its axial movement,

- node fixing the insert from rotation in the housing.

ACCORDING TO THE INVENTION

- the upper base of the body is made in the form of a flange with holes for the studs and with an annular groove for the o-ring,

- diametrically detachable halves of the insert are pivotally interconnected, and in the closed state are connected by a latch,

- the upper part of the insert in the form of a clip is located below the upper surface of the base and interacts with the sliders with a conical surface made on the upper end of the clip,

- while interacting with the clamp the end face of the sliders has the shape of a mating conical surface,

- and the unit for fixing the insert from turning in the housing is made in the form of two diametrically opposite supporting protrusions located on the conical surface of the clip and interacting with the sliders.

The invention is illustrated by drawings:

- in FIG. 1 shows the inventive sealant in operating position;

- in FIG. 2 is a view A in FIG. one;

- in FIG. 3 is a plan view of an open insert disassembled from a lead pipe;

- in FIG. 4 is a section BB in FIG. one;

- in FIG. 5 is a cross-section BB in FIG. one.

The inventive sealant comprises a housing 1 (Fig. 1), in which a through axial channel 2 is made, the lower portion 3 of which has the shape of a round truncated cone expanding upward, the upper base 4, the lower flange 5 for attachment to the wellhead, insert 6, fixation unit 7 insert 6 in the housing 1, made in the form of sliders 8 with a tapered surface 9 and screw drives 10 with control handles 11 located in the radial holes 12 of the upper base 4, and the fixing unit 13 of the insert 6 from turning in the housing 1. The upper base 4 ( Fig. 2) for mustache The installation of additional sealing equipment is made in the form of a flange with holes 14 for studs (not shown) and with an annular groove 15 for a sealing ring (not shown).

The insert 6 (Fig. 1) includes a sealing block, consisting of a clamp 16 with a conical surface 17, a support 18 and located between the clamp 16 and the support 18 of the sealing collar 19 with a conical surface 20, and made of two halves with lines of connectors 21, 22, 23. The line of the connector 22 of the cuff 19 to increase the tightness is made in the form of protrusions and mating depressions. The clamp 16 is located below the upper surface of the base 4 and interacts with the sliders 8.

The fixing unit 13 of the insert 6 from turning in the housing 1 is made in the form of two diametrically opposite supporting projections 24 located on the conical surface 17 of the clamp 16, interacting with the sliders 8.

The connection of the clamp 16, the sealing collar 19 and the support 18 is carried out by the studs 25 and the nuts 26. In this case (Fig. 2), the central square hole 27 is made in the clamp 16, the cuff 19 and the support 18. The split halves of the clamp 16, and therefore the sealing collar 19 and supports 18 are pivotally interconnected by means of axes 28. To fix the detachable halves of the insert 6 in the closed state on the lead pipe 29, the clip 16 is provided with a latch 30 (Fig. 3).

The sliders 8 in the front part interacting with the clamp 16 have a rectangular shape 31 in cross section (Fig. 4), and in the rear part they have a cylindrical shape 32 (Fig. 5). Accordingly, the holes 33 securing the sliders 8 from the rotation have a reciprocal rectangular shape 34 in the front and a cylindrical shape 35 in the rear.

The inventive device operates as follows.

The housing 1 of the sealant (Fig. 1) is mounted and fixed on the wellhead flange (not shown), after which the lead pipe 29 is lowered into the through axial channel 2 with the drill string assembly attached to it, including drill pipes, a turbodrill and a rock cutting tool (not shown) .

If it is necessary to seal the mouth, the insert 6 is preliminarily mounted on the lead pipe 29, for which the latch 30 is squeezed out, the detachable halves of the insert 6 are parted (Fig. 3) and brought around the lead pipe 29 until the latch 30 works to fix the insert 6 on the lead pipe 29 (Fig. . 2).

Compared with the prototype, this operation of the inventive sealant is less time-consuming, since for installation it is only necessary to cover the lead pipe 29 with the detachable halves of insert 6 and fix the latch 30, it is safer since installing insert 6 on the lead pipe 29 does not require manual holding and centering of the lead pipe 29 to comply with the alignment of its longitudinal axis with the center of the square hole 27 of insert 6 or less, which reduces the downtime of the drilling process.

After that, the insert 6 mounted on the lead pipe 29 (Fig. 1) is installed in the through axial channel 2 by lowering the lead pipe 29 until the sealing collar 19 contacts the conical section 3 of the through axial channel 2 and fixed in the housing 1 by rotation of the handles 11. When installing the insert 6 visually control the location of the support protrusions 24 relative to the sliders 8, ensuring the rotation of the support protrusions 24 relative to the direction of movement of the sliders 8 with the aim of guaranteed contact of the conical surfaces 9 of the sliders 8 with the conical the rests 17 of the clamp 16. When fixing the insert 6 in the housing 1, the screw drives 10 move the sliders 8, which, interacting with the conical surfaces 9 with the conical surfaces 17 of the clamp 16, move the insert 6 down, recessing the sealing collar 19 in the conical section 3 of the through axial channel 2 s simultaneously compressing the sealing sleeve 19 of the outer square surface of the lead pipe 29, providing reliable sealing of the wellhead. In this case, the fixation of the sliders 8 from the rotation in the holes 33 (Figs. 4 and 5) is ensured by the rectangular cross-sectional shape 31 of the sliders 8 and the similar cross-sectional shape 34 of the holes 33.

The set of operations necessary for the installation and preparation for operation of the inventive sealant is less time-consuming and requires significantly less time in comparison with the prototype, since it eliminates the implementation of several operations and does not require the involvement of additional personnel, which also ensures the ease of operation of the inventive sealant.

After inserting insert 6 into the housing 1, the process of drilling a well begins with the supply of drilling fluid under pressure. The lead pipe 29 moves along the sealing collar 19 of the insert 6, the reactive moment from the turbodrill is transmitted to the clamp 16 of the insert 6 and, further, from the support protrusions 24 to the sliders 8 and the housing 1 of the sealant. The transmission of torque from the support projections 24 to the sliders 8 by means of a stop increases the reliability of fixing the insert 6 from rotation.

If gaps occur during drilling, in case of wear of the working surface of the sealing collar 19, rotation of the nuts 26 on the studs 25 provides a more tight crimp of the sealing material of the collar 19 around the surface of the drive pipe 29.

After conducting a drilling cycle with the aim of further building up the drill string, carrying out tripping operations and moving the insert 6 along the lead pipe 29 to its original position above the lower sub, which is necessary for the next sealing cycle, depressurize, rotate the cranks 11 to slide the sliders 8, insert 6 by lifting the lead pipe 29 is removed from the axial channel 2 and removed from the lead pipe 29 by opening the latch 30 (Fig. 3).

Compared with the prototype, this operation of the inventive sealant is less time-consuming, since to remove the insert 6 from the lead pipe 29, it is only necessary to unlock the latch 30, separate and remove the detachable halves of the insert 6 from the lead pipe 29, while there is no need to disassemble the insert 6. In addition, this operation is safer than the prototype, since removing the insert 6 from the lead pipe 29 does not require manual retention of the lead pipe 29, and is shorter, which reduces the downtime of the drilling process and the likelihood of a stationary drill pipe hanging on the wedges in the well slider, which prevents the occurrence of an emergency.

Thanks to the dismantling of the insert 6 from the lead pipe 29, the abrasive effect of the outer square surface of the lead pipe 29 on the square hole 27 of the sealing collar 19 and its abrasive wear are eliminated.

Due to the fact that the upper base 4 of the housing 1 is made in the form of a flange with holes 14 for the studs and with an annular groove 15 for the sealing ring (Fig. 2), and the clamp 16 is located below the upper surface of the base 4 (Fig. 1), it is provided if necessary the ability to install additional sealing equipment, which increases the safety of the inventive sealant and expands its operational capabilities.

Thus, the use of the inventive device provides ease of use, increasing reliability, safety, reducing the complexity and time costs when using, as well as expanding operational capabilities compared to the analogue and prototype.

Claims (12)

The lead pipe sealant at the wellhead with the perception of the reactive moment from the rotation of the turbodrill, containing: - a housing with an upper base and a lower flange in which a through axial channel for passing pipes is made, the lower portion of which under the upper base has the shape of a round truncated cone, expanding upwards, - an insert installed in the through axial channel of the housing in the form of a sealing block consisting of two halves with a diametrical connector and containing a clamp, a support and a sealing collar located between them, connected by means of studs and nuts, - moreover, in the clamp, support and sealing cuff, a central square hole is made, and the outer surface of the cuff is conical and interacts with the conical surface of the through axial channel of the housing, - node fixing the insert in the housing, made in the form of movable sliders with a screw drive, located in the radial holes of the upper base and interacting with the insert without the possibility of its axial movement, - node fixing the insert from rotation in the housing, characterized in that - the upper base of the body is made in the form of a flange with holes for the studs and with an annular groove for the o-ring, - diametrically detachable halves of the insert are pivotally interconnected, and in the closed state are connected by a latch, - the upper part of the insert in the form of a clip is located below the upper surface of the base and interacts with the sliders with a conical surface made on the upper end of the clip, - while interacting with the clamp the end face of the sliders has the shape of a mating conical surface, - and the unit for fixing the insert from turning in the housing is made in the form of two diametrically opposite supporting protrusions located on the conical surface of the clip and interacting with the sliders.

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