RU2784260C1 - Connector for a flexible pipe with the bottom-hole equipment - Google Patents

Abstract

FIELD: petroleum industry.

SUBSTANCE: invention relates to apparatus for work with flexible metal pipes when drilling a horizontal section of the wellbore of petroleum and gas boreholes. Connector for a flexible pipe with the bottom-hole equipment comprises a body with an internal thread in the lower part for the connection to the bottom-hole equipment. The middle part of the body has annular grooves for sealing rings on the inner surface thereof. An internal conical surface is made in the upper part of the body, with the base of the cone facing up. A spider is placed in the inner conical surface of the body, made in the form of slips located in the gap between the inner conical surface of the upper part of the body and the outer wall of the flexible metal pipe. A rigid metal branch pipe is installed inside the flexible metal pipe. The spider is made in the form of a dovetail joint. Grooves are made on the inner conical surface of the body, wherein the slips are installed configured for limited movement within the grooves. Herewith, the angle of the conical surface of the body to the central axis thereof is 15 °. The inner surface of the slips is made corrugated and quenched. A pressure ring interacting with the upper ends of the slips is secured on the upper end of the body. The pressure ring is equipped with through holes, and threaded holes are made on the upper end of the body for attaching the pressure ring to the upper end of the body with the bolts installed in the through holes of the pressure ring.

EFFECT: structural simplification of the apparatus, higher fixation security of the connection: flexible pipe – connector - bottom-hole equipment, and eliminated restrictions in the passage of the apparatus along the diameter of the wellbore, simplified assembly and disassembly of the apparatus.

1 cl, 3 dwg

Description

The invention relates to devices for working with flexible metal pipes during overhaul, drilling a horizontal section of an oil well.

A device is known for working with a flexible pipe, preferably when drilling oil wells (patent RU No. 2153058, IPC E21B 19/22, publ. 07/20/2000), containing a rotating coil mounted on a shaft with a tubular central part adapted for winding and winding a sponge pipe , which is connected to the pumping device for supplying liquid into the coiled pipe through the first swivel device located at one end of the shaft, and the hydraulic conduit entering inside the flexible pipe downstream than the first swivel device and connected to at least one hydraulic line through the second hinge device located at the second end of the shaft, the device additionally contains at least one electrical cable entering the inside of the flexible pipe downstream than the first hinge device and connected to the electrical conduit through the third hinge device located at the second end of the shaft .

Design flaws:

- firstly, a high probability of an emergency in the process of drilling a horizontal section of the wellbore, since when pressing a flexible thin-walled metal pipe with a wedge grip with sharp ridges, the latter will inevitably deform at the junction with the downhole tool, with possible subsequent breakage of the downhole tool;

- secondly, the low reliability of the connection of this device with the downhole tool and the possibility of deformation at the junction. In addition, the connection is unstable to vibration during drilling due to the lack of a locking device;

- thirdly, the complexity of assembly-disassembly, due to the lack of a dismantling device, which does not ensure complete release of the flexible pipe from the wedge grip. In addition, deformation at the junction of the coiled tubing with the downhole tool leads to a decrease in the diameter of the coiled tubing, which causes an increase in hydraulic losses and, as a result, an increase in the absolute pressure on the mud pumps.

The closest in technical essence and the achieved result is a device for connecting a flexible metal pipe with downhole equipment, containing a body with an internal thread in the lower part for connection with downhole equipment, the middle part of the body on the inner surface has annular grooves for sealing rings, in the upper part of the body the inner conical surface is made with the base of the cone up, and in the inner conical surface of the body there is a wedge grip made in the form of wedge dies located in the gap between the inner conical surface of the upper part of the body and the outer wall of the flexible metal pipe, and a rigid metal pipe is installed inside the flexible metal pipe (patent RU No. 2196216, IPC E21B 17/03, published on January 10, 2003). Also, the device contains a pressure nut and a locking device that prevents unscrewing during drilling, and the upper part of the pressure nut is made truncated-conical with radial grooves forming ribs having transverse holes for the handle for screwing-breaking the threaded connection, and the radial grooves have annular grooves, under which there are dismantling holes of the wedge grip, made in the form of wedge dies, located in the gap between the inner conical surface of the upper part of the body and the outer wall of the flexible metal pipe.

Design flaws:

- firstly, the complexity of the design, due to the large number of units and parts (pressure nut with ribs having transverse holes for the handle for screwing and unscrewing the threaded connection; radial grooves with annular grooves, as well as a locking device that prevents spontaneous unscrewing of the pressure nut in the well );

- secondly, low reliability of fixing the connection: boom pipe - connector - downhole equipment. In the process of screwing onto the pressure nut body, all wedge dies are assembled (knocked down) in one part of the inner conical surface, which does not allow to securely grip the flexible metal pipe;

- thirdly, the restriction of the passage of the device along the diameter of the wellbore, which occurs due to the increased outer dimensions of the device, because the pressure nut is screwed onto the body of the device from the outside;

- fourthly, the complexity of assembly and disassembly, associated with the need to use a chain wrench to screw the pressure nut onto the housing, followed by fixing the stopper in order to prevent the thread from turning off.

The technical objectives of the invention are to simplify the design of the device, increase the reliability of fixing the connection: flexible pipe - connector - downhole equipment, as well as the exclusion of restrictions on the passage of the device along the diameter of the wellbore, simplifying the assembly and disassembly of the device.

Technical problems are solved by a flexible pipe connector with downhole equipment, containing a body with an internal thread in the lower part for connection with downhole equipment, the middle part of the body on the inner surface has annular grooves for sealing rings, in the upper part of the body an inner conical surface is made with the base of the cone up, and a wedge grip is placed in the inner conical surface of the body, made in the form of wedge dies located in the gap between the inner conical surface of the upper part of the body and the outer wall of the flexible metal pipe, and a rigid metal pipe is installed inside the flexible metal pipe.

What is new is that the wedge grip is made in the form of a dovetail connection, while grooves are made on the inner conical surface of the body, wedge dies are installed in the grooves with the possibility of limited movement within the grooves, while the angle of the conical surface of the body to the central axis of the body is 15°, while the inner surface of the wedge dies is corrugated and hardened, and a pressure ring is fixed to the upper end of the body, interacting with the upper ends of the wedge dies, and the pressure ring is equipped with through holes, and threaded holes are made on the upper end of the body for attaching the pressure ring to the upper end of the housing with bolts installed in the through holes of the pressure ring.

In FIG. 1 is a schematic representation of a coiled tubing connector with downhole equipment.

In FIG. 2 shows the section A-A of the coiled tubing connector with downhole equipment.

In FIG. 3 shows a B-B section of a coiled tubing connector with downhole equipment.

The connector contains a housing 1 (see Fig. 1, 2) with an internal thread 2 (see Fig. 1) in the lower part for connection with downhole equipment (not shown in Fig. 1-3). Any known equipment can be used as downhole equipment, for example, a blind packer, i.e. plug bridge (manufacturing and service company "Yugson-Service" Russian Federation, Tyumen.) with a hydraulic fit, designed to isolate the water inflow zone in the well during the repair of wells.

The middle part of the body 1 (see Fig. 1) on the inner surface has annular grooves 3 under the sealing rings 4. In the upper part of the body 1, an inner conical surface 5 (see Fig. 1, 2) is made with the base of the cone up.

In the inner conical surface of the body 1 there is a wedge grip 6 made in the form of a dovetail connection, while on the inner conical surface 5 of the body 1 grooves 7 are made (see Fig. 1, 2), which are connected to the inner conical surface 5 of the body 1 rigidly, for example by welding.

In the grooves 7 (see Fig. 1 and 2) installed wedge dies 8, having the possibility of limited movement within the grooves 7.

The angle of the inner conical surface 5 of the body 1 to the central axis of the device is 15° (see Fig. 1), while the wedge dies 8 (see Fig. 1, 2) have a corrugated hardened inner surface 9. A pressure plate is installed on the upper end of the body 1 ring 10 (see Figs. 1 and 3), interacting with the upper ends of the wedge dies 8. The pressure ring 10 is equipped with through holes 11 (for example, in the amount of four pieces), and threaded holes 12 are made on the upper end of the body 1 (see Fig. 1) (in the amount of four pieces) for fastening the pressure ring 10 to the upper end of the housing 1 with bolts 13 (see Fig. 1, 3) (in the amount of four pieces) installed in the through holes 11 of the pressure ring 10.

It has been experimentally established that the angle of the conical surface 5 of the body 1 to the central axis of the device, equal to 15°, provides the maximum gripping force of the flexible metal pipe 14 (see Fig. 1, 2, 3) in the course of work, which increases the reliability of the device.

Inside the flexible metal pipe 14, a rigid metal pipe 15 is installed (see Fig. 1, 2), which prevents its deformation.

Coiled tubing connector with downhole equipment works as follows.

A coil with a wound flexible metal pipe 14 is installed on the transport device, for example, with a diameter of 60.3 mm, a length of 2300 m, and a wall thickness of 4.0 mm.

At the lower end, a rigid metal pipe 15 is mounted inside the flexible metal pipe 14. Then, through the lower end of the flexible metal pipe 14, it is first passed into the pressure ring 10.

O-rings 4 are installed in the annular grooves 3 in the middle part of the body 1. Next, a wedge grip 6 is assembled, made in the form of a dovetail connection. To do this, in the grooves 7 (see Fig. 1 and 2) of the inner conical surface 5 of the body 1 is inserted from top to bottom wedge dies 8, for example, in the amount of four pieces (see Fig. 2). Then, the lower end of the flexible metal pipe 14 is inserted into the housing 1 until a tight fit with sealing rings 4.

Next, the pressure ring 10 is lowered to the upper end of the wedge dies 8 (see Fig. 1 and 3). Then the bolts 13 are installed in the through holes 11 of the pressure ring 10. By turning the pressure ring 10 relative to the body 1, the bolts 13 are aligned with the threaded holes 12 of the body 1.

The bolts 13 are screwed into the threaded holes 12 of the body 1. As a result, the lower end of the pressure ring 11 is simultaneously affected by all the upper ends of the wedge dies 8 (in the amount of 4 pieces).

Wedge dies 8 move down within the grooves 7 and rigidly and motionless with their inner corrugated hardened surface 9 fix the flexible metal pipe 14 in the housing 1 of the connector. Next, on the internal thread 2 of the housing 1 screwed, the above bridge plug with a hydraulic fit.

Next, a device with a bridge plug is lowered on a flexible metal pipe 14 into the well in the interval of water inflow isolation.

Then, at the wellhead, a pumping unit, for example, brand TsA-320, is tied with the upper end of the flexible metal pipe 14 and hydraulic pressure is created in the flexible metal pipe 14, for example, 6.0 MPa, while, for example, the shear element is destroyed (in Fig. 1 -3 not shown) of a bridge plug with a hydraulic landing and it is planted in the well and the bridge plug (downhole equipment) is disconnected from the connector. The pump unit is dismantled from the flexible metal pipe 14 (see Fig. 1). Further from the well on the flexible metal pipe 14 the proposed connector is removed.The device is disassembled in the reverse order.

The design of the device is simplified, since the pressure nut with ribs having transverse holes for the handle for screwing-unscrewing the threaded connection is excluded from the design; radial grooves with annular grooves, as well as a locking device for the pressure nut. All this allows to reduce the cost of manufacturing the device without losing the quality of work.

The reliability of fixing the connection increases: flexible pipe - connector - downhole equipment. This is due to the dovetail design, when the wedge dies installed in the grooves move within the corresponding grooves in which they are installed, and therefore the wedge dies do not have the possibility of radial displacement relative to each other as in the prototype.

The restriction of the passage of the device along the diameter of the wellbore, which occurs due to the increased outer dimensions of the device, is excluded, because the pressure nut is excluded from the design, and its role is played by the pressure ring, which has an outer diameter equal to the outer diameter of the device body.

The assembly and disassembly of the device is simplified, since the need is eliminated. using a chain wrench to screw the pressure nut onto the housing, followed by fixing the stopper to prevent the thread from turning off. It is enough to use a hand wrench, for example M10, to wrap four bolts, which also reduces the time of assembly and disassembly. Thus, the device is compact and easy to use in comparison with the prototype.

Coiled tubing connector with downhole equipment allows:

- simplify the design of the device;

- increase the reliability of fixing the connection: boom pipe - connector - downhole equipment;

- exclude restrictions on the passage of the connector along the diameter of the wellbore;

- to simplify the assembly and disassembly of the device.

Claims (1)

Coiled tubing connector with downhole equipment, containing a body with an internal thread in the lower part for connection with downhole equipment, the middle part of the body on the inner surface has annular grooves for sealing rings, in the upper part of the body the inner conical surface is made with the base of the cone up, and in the inner conical On the surface of the housing there is a wedge grip made in the form of wedge dies located in the gap between the inner conical surface of the upper part of the housing and the outer wall of the flexible metal pipe, and a rigid metal pipe is installed inside the flexible metal pipe, characterized in that the wedge grip is made in the form of a joint. dovetail", while grooves are made on the inner conical surface of the body, wedge dies are installed in the grooves with the possibility of limited movement within the grooves, while the angle of the conical surface of the body to the central axis of the body is 15°, At the same time, the inner surface of the wedge dies is corrugated and hardened, and a pressure ring is fixed to the upper end of the body, which interacts with the upper ends of the wedge dies, and the pressure ring is equipped with through holes, and threaded holes are made on the upper end of the body for attaching the pressure ring to the upper end of the body bolts installed in the through holes of the pressure ring.

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