RU2534118C1 - Water influx interval shutoff device in open hole of horizontally-branched well - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: water influx interval shutoff device in an open hole of horizontally-branched well comprises a tubing string with packers run in hole. From below the tubing string by a hydraulic disconnecting switch is connected to a double-packer assembly consisting of two swellable packers interconnected by an inter-packer tube, which length exceed length of water influx in the well, at the lower end of the double-packer assembly there is a perforated tube which is in its initial position is covered hermetically by a bushing from inside and fixed by a shear pin, at that at the lower tube end there is a hydraulic whipstock that ensures ingress into an open hole of the horizontally-branched well, at that in the operating position the bushing moves downwards in a limited way under action of the gating element run in at the tubing string from the wellhead until it thrusts into the butt end of the hydraulic whipstock with opening of perforated holes of the tune and fixation in the tube below its perforated holes.

EFFECT: device allows increased operational reliability due to simplified design and sealing quality of the water influx interval in process of the well operation in result of use of water- and oil-swellable packers depending on type of the liquid in the interval wherein they are set, and shutoff of water influx intervals in an open hole of the horizontally-branched well, reduced costs for installation and maintenance in process of the well operation as the device is run in to the well separately from production equipment.

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Description

The invention relates to the oil and gas industry and may find application when disabling water flow in the open trunk of a multilateral horizontal well.

A device for isolating formations in a well is known (patent RU No. 2071545, IPC ЕВВ 33/12, published in Bull. No. 1 dated 01/10/1997), including upper and lower packers interconnected by pipes, each of which has a housing with radial channel, a casing, forming an annular cavity with the outer surface of the housing, an annular cone and slips placed outside the housing with the possibility of interaction with each other, and check valves, the device is equipped with a sleeve mounted above the upper packer and connected to the housing by an adapter, which dinen with an annular cone of the upper packer, a sleeve and stepped bushings, the smaller steps of which are oriented in opposite directions, large steps are placed in the annular cavities, and check valves and packer sealing elements are installed in the stepped bushings placed between the shells and the ring cones, while the sub is connected with clutch shear screws and is made with the possibility of axial movement relative to the clutch until it stops against the annular cone of the upper packer.

The disadvantages of this device are:

- firstly, the complexity of the design associated with a large number of nodes and parts;

- secondly, the lack of reliability associated with the complex principle of operation, and the nodes of the device are interdependent and operate in a specific, dependent on each other sequence;

- thirdly, the impossibility of isolation in the open trunks of a multilateral horizontal well.

The closest in technical essence and the achieved result is a device for shutting off formation water inflow in wells with horizontal bottom hole (utility model patent RU No. 30158, IPC ЕВВ 33/12, published in Bull. No. 17 dated 06/20/2003), including inflatable packers launched on the tubing string, while one of the ends of the tubing is plugged to provide simultaneous packing of the wellbore, and the other is connected to production equipment, and the tubing is made in tubing s opposite the productive strata, while in the tubing opposite the inflatable packers are made, additional holes, which are provided with straight valves and pressure relief mechanism for each of the inflatable packer. Check valves are installed in the channels of the tubing, and a deep pump is installed inside the tubing, the tubing is additionally equipped with centralizers, which are located in close proximity to the inflatable packers.

The disadvantages of the device are:

- firstly, the complexity of the design associated with a large number of nodes and parts (direct and check valves, centralizers);

- secondly, the high cost of installation (dismantling) and maintenance of the device during operation, since the operational equipment is included in the device to shut off the inflow of produced water, therefore, in case of breakdown, for example, jamming of the plunger of the deep pump, it is necessary to remove the entire device from the well;

- thirdly, the inability to turn off the intervals of water inflow in the open trunk of a multilateral horizontal well;

- fourthly, the low quality of sealing (shutdown) of the water inflow interval using inflatable packers in an open wellbore, as well as the complex technology of landing inflatable packers;

- fifthly, insufficient reliability due to possible failures in the operation of direct and non-return valves.

The technical objectives of the proposal are to increase the reliability of the device and the quality of the sealing of the interval of water inflow in the open wellbore with the ability to disable the interval of water inflow in the open well of a multilateral horizontal well, simplifying the design of the device, as well as reducing the cost of its maintenance.

The stated technical problems are solved by a device for disabling the interval of water inflow in the open trunk of a multilateral horizontal well containing a string of tubing with packers that is lowered into the well.

What is new is that from below the tubing string is connected using a hydraulic disconnector to a two-packer arrangement consisting of two swellable packers connected by an interpacker pipe, the length of which exceeds the length of the water inflow interval in the well, a perforated pipe is installed at the lower end of the two-packer assembly, in the original the position is hermetically closed from the inside by a sleeve and fixed by a shear element, while a hydraulic diverter is installed at the lower end of the nozzle, providing the first entry into the open hole of a multilateral horizontal well, and in the working position, the sleeve has the possibility of limited downward movement under the action of a shut-off element that is lowered along the string of tubing from the wellhead until it stops against the end of the hydraulic diverter with opening of the perforated nozzle openings and fixing in the nozzle below its perforated holes.

Figure 1 and 2 shows the proposed device in the process.

A device for disabling the water inflow interval in the open wellbore 1 ', 1''... 1 ^{n of the} horizontal well 1 (Fig. 1) comprises a column running down into the multilateral well 1, consisting, for example, of two open shafts 1' and 1 '' tubing (tubing) 2. For example, a tubing string with a diameter of 73 mm according to GOST 633-80 is used.

The tubing string 2 below is connected using a hydraulic disconnector 3 to a two-packer arrangement consisting of two swellable packers: the top 4 and bottom 5, interconnected by the packer pipe 6. The length L of the packer pipe 6 exceeds the length A of the water inflow interval in the open borehole of a multilateral horizontal well 1 .

As a hydraulic disconnector 3, any device can be used to disconnect the pipe string, for example, a left sub or shear element (not shown in Figs. 1 and 2), which are destroyed when the device is unloaded to the bottom hole 7 (see Fig. 1) of horizontal well 1.

At the lower end of the two-packer arrangement, a pipe 9 perforated by the holes 8 is installed, in the initial position hermetically closed from the inside by the sleeve 10 and fixed by the shear element 11.

At the lower end of the pipe 9, a hydraulic diverter 12 is installed, which ensures that a multi-hole horizontal well 1 enters the open hole 1 'or 1' '.

In the working position, the sleeve 10 has the possibility of limited downward movement against the end 13 of the hydraulic diverter 12 with the opening of the perforated holes 8 of the pipe 9 and fixing the sleeve 10 in the pipe 9 below its perforated holes 8.

The fixing of the sleeve 10 relative to the pipe 9 is carried out, for example, by a split retaining ring (not shown in FIGS. 1 and 2) installed in the inner ring sample of the pipe 9 (see FIG. 1) below the perforated holes 8.

The limited movement of the sleeve 10 relative to the nozzle 9 is carried out under the action of the locking element, lowered along the string of tubing until it fits into the upper end of the sleeve 10, for example, using the squeeze plug 14 (see figure 2), pushed along the tubing string 2 under the action overpressure from above.

As packers 5 and 6, swellable packers, for example, TAM grades, are used.

The hydraulic diverter 12 (figure 1) is equipped with a bottom rod 16 and a nozzle 17 with a hole. The rod 16 of the hydraulic diverter 12 under the action of excess fluid pressure in the pipe string 2 allows the pipe string 2 to enter any of the open shafts 1 'or 1' 'of the multilateral well 1, for example, into the open well 1'. The nozzle 17 with the hole of the rod 16 of the hydraulic diverter 12 provides flushing during tripping operations of the pipe string 2.

As a hydraulic diverter 5, devices widely used by OAO Tatneft for flushing and acid treatments of multilateral wells described in patents RU No. 2318111, IPC ЕВВ 23/00, publ. 02/27/2008, or No. 2318112, IPC Е21В 23/00, publ. 02/27/2008 in Bul. No. 6.

The device operates as follows.

To determine the interval of water inflow into the multilateral horizontal well 1, a geophysical device (not shown in FIGS. 1 and 2) of any known design is lowered, for example, a complex device of a modular type of the brand GDI-7 manufactured by Tatneftegeofizika-Universal LLC (Republic of Tatarstan, Bugulma) intended for conducting hydrodynamic studies in open trunks of multilateral horizontal wells.

With the help of this device, geophysical studies are carried out, for example, thermometry and debitometry (inflow), and the water-cut interval in the open trunks 1 'and 1' 'of a multilateral horizontal well 1 is determined.

For example, it is determined that the interval of water inflow is the interval of 970-1120 m of open shafts 1 'and 1' '(see Fig. 1) of a multilateral horizontal well 1.

To turn off the interval of water inflow 15 (interval 970-1120 m) in the open shafts 1 'and 1' 'of a multilateral horizontal well 1, the proposed device is assembled at the wellhead, as shown in Fig. 1.

The device is lowered into a multi-hole horizontal well 1 until the hydraulic diverter 12 is opposite the entrance to the open hole 1 '(Fig. 1), for example, in the range of 1010 m. During the descent of the device, the multi-hole well 1 is flushed through the nozzle 17 with an opening the rod 16 of the hydraulic diverter 12. Flushing the horizontal well 1 during the descent of the device eliminates its blockage by sludge.

Then, from the mouth of a multilateral horizontal well 1, using any known pump, for example, a cementing unit of the CA-320 brand, a process fluid is pumped into the tubing string 2, for example, fresh water with a density of 1000 kg / m ^{3 is used} , and an excess pressure of the fluid is created , which is transmitted through the internal space of the tubing string 2 to the internal space (not shown in FIGS. 1, 2) of the hydraulic diverter 12.

As a result, the stem 16 of the hydraulic diverter 12 is rotated towards the open barrel 1 '. Further, without reducing the overpressure in the tubing string 2, the tubing string 2 is continued to be lowered into the open hole 1 'of the multilateral well 1 to the bottom 7 (for example, in the interval 1140 m) of the open hole 1' of the multilateral well 1. This process operation allows you to determine the exact location (hit) of the tubing string 2 in a given open hole 1 ', since the open shafts 1' and 1 '' of the multilateral well 1 have different values of the faces. In this case, the lower swellable packer 5 is located in the open hole 1 ′ below (to the right) of the inflow interval 15, and the upper swellable packer 4 is in the main trunk of the horizontal well 1 above (to the left) of the inflow interval 15.

The lower swellable packer 5, located in the open hole 1 ′, is oil-swellable, since it is located in the flooded oil-bearing interval, and the upper packer 4, located in the main trunk of a multilateral horizontal well, is water-swellable, since it is located in the flooded interval. Swellable packers 4 and 5 swell and hermetically isolate the interval of water inflow 15 length A.

Swellable packers 4 and 5 are an elastomer of specialized composition that swells due to absorption of fluid in the well and overlaps the annulus in any open or cased trunks. Thus, by installing swellable packers 4 and 5 at the boundaries of the watering of well 1, according to the results of geophysical studies, the irrigated horizontal section of the production interval is turned off (not shown in FIGS. 1 and 2).

From the mouth of a multi-hole horizontal well 1 (see FIG. 2), a squeeze plug 14 is installed in the pipe string 2, which is pushed through the pressure pump created by the pump unit CA-320, for example, fresh water with a density of 1000 kg / m ³ the inner space of the tubing string 2.

The squeeze plug 14 under the action of excess fluid pressure moves along the tubing string 2 and reaches the sleeve 10. When excessive pressure is reached in the tubing string 2, for example 7 MPa, the shear element 11 is destroyed.

Then the squeeze plug 14 moves the sleeve 10 downward relative to the pipe 9 against the end 13 of the hydraulic diverter 12 with the opening of the perforated holes 8 of the pipe and fixing (not shown in Figs. 1 and 2) of the sleeve 10 (see Fig. 1) in the pipe 9 below its perforated holes 8.

Next, the hydraulic disconnector 3 is activated, for example, the tubing string 2 is unloaded to the bottom 7, while the pins (not shown in Figs. 1 and 2) are broken, fixing the two-packer arrangement relative to the tubing string 2 (see Fig. 2), and disconnection tubing string 2 from a two-packer arrangement.

Next, the tubing string 2 is removed from the multi-hole horizontal well 1. Production equipment is lowered into the well 1, for example, an elevator pipe string with a submersible pump.

The proposed device allows to increase reliability in operation by simplifying the design and the quality of the sealing of the water inflow interval during the operation of the well through the use of water and oil swell packers depending on the type of fluid in the interval in which they are installed, and to shut off the intervals of water inflow in the open hole multilateral horizontal wells, while reducing the cost of installation (dismantling) and maintenance during operation of the well, since the device is lowered into kvazhinu separately from the production equipment.

Claims (1)

A device for shutting off the water inflow interval in the open hole of a multilateral well horizontal well containing a tubing string with packers being lowered into the well, characterized in that the tubing string using a hydraulic disconnector is connected to a two-packer arrangement consisting of two swellable packers connected from below an interpacker pipe, the length of which exceeds the length of the water inflow interval in the well, a perforated nozzle is installed at the lower end of the two-packer assembly to, in the initial position, hermetically closed from the inside by a sleeve and fixed by a shear element, while at the lower end of the nozzle a hydraulic diverter is installed, which ensures that a multilateral horizontal well penetrates into the open trunk, and in the working position the sleeve has the possibility of limited downward movement under the action of a locking element that is lowered along the tubing string from the wellhead to the end in the end of the hydraulic diverter with the opening of the perforated nozzle holes and sations in the pipe below its perforated holes.

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