RU185859U1 - DEVICE FOR CARRYING OUT A MULTI-STAGE HYDRAULIC GROUND RIG (MHF) FOR ONE LIFT-LIFTING OPERATION - Google Patents

Abstract

The utility model relates to the field of the oil and gas industry, in particular to devices for oil production, and can be used for multi-stage hydraulic fracturing (hydraulic fracturing) in a production well. The technical result, the achievement of which the present utility model is directed, is to reduce the time spent on performing multi-stage hydraulic fracturing (MHF) in multilayer wells, and to increase the efficiency of impact on individual reservoirs by perforating the intervals of the proposed stages of MHF and MHF itself in one tripping operation using piercing perforation. A device for conducting multistage hydraulic fracturing consists of a tubing string, on which a top selective packer with a through hole, a lower selective packer with a through hole, a pressure shut-off valve, a piercing device perforating the casing in intervals are mounted the planned hydraulic fracturing, and between the upper and lower packers in the tubing string there is a frac port, under which the perforated nozzle of the tubing string is located.

Description

The utility model relates to the field of the oil and gas industry, in particular to devices for oil production, and can be used for multi-stage hydraulic fracturing (hydraulic fracturing) in a production well.

A device is known for sequential perforation of several intervals in one round trip operation (utility model patent No. RU 134211 of 08/08/2013), containing at least lower, middle and upper heads firing (horizontal) mounted sequentially on the tubing and at least lower, middle and upper packers, with each of the packers located above the corresponding HS, and the lower and upper packers are capable of simultaneous packing with an effort less than the packing effort of the middle packer. In general terms, the principle of operation of the claimed device is based on the fact that after perforation of interval No. 1, fluid flow enters the tubing and stops after installing packers No. 1 and No. 3; after perforation of interval No. 2, fluid flow enters the tubing and stops after installing packer No. 2; after perforation of interval No. 3, fluid inflow enters the tubing. When all three packers are transferred to the transport position, fluids arrive from all three intervals. The above makes it possible to reduce the number of STRs.

The disadvantages of the known device are:

- the use of cumulative perforators that require recharging and, as a result, removing the device from the well;

- the device is intended only for perforation of several intervals for one descent, however, it is not intended for the implementation of multi-stage hydraulic fracturing (hydraulic fracturing) in one descent and lift operation;

- the need to use at least three perforators, which complicates the design and maintenance of the device.

Also known is a method and device for remote intervention using logical valve control (patent for the invention No. RU 2358090, from 29.07.2003). The system contains two or more valves, each of which is adapted to independently act in a given pressure range. Two or more valves are capable of independently performing a series of sequential events by one or more downhole tools based on pressure during application of fluid pressure to two or more valves. Provides the ability to reuse remote access in a single descent of the bottom of the casing string. In FIG. 1 shows a simplified assembly system with a downhole tool that uses a logic valve for remote intervention. The borehole 1 has a casing 2, which is fixed in an appropriate place by cement 3. Between the borehole 1 and the underground formation 4 by means of perforations 6, hydraulic communication is provided through the casing and cement. The borehole assembly 5 is deployed by deploying means, such as a spirally coiled tubing 7 extending into the bore 1. A coiled tubing 7 provides a supply to the logic valve 10 to remotely interfere with the fluid flow and pressure. The flushing and circulating flow is supplied from the flushing tool 24, which may be an auxiliary component of the logic valve 10 for remote intervention. An inflatable packer 8 is connected below the valve 10. Between the filters 13 and 14 through the mandrel 79, a stable flow of fluid is ensured. A fluid may pass between the filters 13 and 14 in any direction. Below the wedges 25, a perforation system 9 for selective shooting is connected. The borehole assembly 5 may be deployed using suitable means, including connected piping, traction devices, or a cable, not limited to a spiral tubing. The annular space 11 is the space between the casing 2 and the node 5 of the borehole, as well as between the casing 2 and the deployment tool 7. To excite in multiple zones in one descent, an example of a possible sequence of events provided by a borehole unit 5 may include the following: 1) the descent packer passes to a predetermined depth when the fluid circulates through a spiral-wound pipeline; 2) perforation; 3) moving the bottom equipment of the casing below the perforations; 4) installation of wedges; 5) leaching of debris from the installation site of the packer; 6) inflating the packer; 7) equalization of pressure on the packer during inflation; 8) overlapping the pressure equalization path after inflating the packer; 9) the implementation of the excitation program; 10) opening the leveling hole before blowing off the packer; 11) leaching of any residual material after excitation from the location of the packer; 12) blowing off the packer; 13) release of wedges; 14) the circulation of the fluid through a spiral coiled pipeline during the movement of the packer.

The disadvantages of the known technical solutions are:

- the use of a cumulative punch, requiring recharging and, as a result, removing the device from the well;

- the complexity of the design, a high probability of damage.

Also known is a downhole tool for conducting hydraulic fracturing using sandblasting perforation in one round trip. However, when perforating the casing using a sandblasting punch, the casing is opened by supplying a mixture of liquid and abrasive material (quartz sand) under high pressure, in this regard, there is a limit on the number of perforation intervals, since the abrasive material erodes the hydraulic nozzle. In addition, it is necessary after each hydro-sandblasting perforation to flush the well from sand before hydraulic fracturing, which increases the time to complete the work.

The closest technical solution, selected as a prototype, is a method of hydraulic fracturing and devices for its implementation (patent for invention No. RU 2618545, 02/26/2016), including perforation in the interval of the formation of the well, oriented in the direction of the main maximum stress, descent tubing strings (tubing) with a packer into the well, packer landing, hydraulic fracturing by pumping hydraulic fracturing fluid along the tubing string with a packer through the perforation interval into the reservoir with the image the formation and subsequent fastening of the fracture in the formation by cyclic alternating injection of the carrier fluid with the proppant along the tubing string, pressure relief from the well, depressurization of the packer and extraction of the tubing string with the packer from the well, characterized in that the hydromechanical perforator on the tubing string, perform pairs of perforations along the perimeter of the well from the bottom to the top of the formation with an offset of 30 ° when each pair of perforations is performed After perforation, the tubing string with a perforator is removed from the well, gelled oil is used as a fracturing fluid, the total volume of gelled oil is determined, the gelled oil is pumped through the tubing string into the formation interval with the formation of a fracture fracture.

The disadvantage of the prototype is the need for perforation of each interval of the wellbore and hydraulic fracturing for several tripping operations, which complicates the process of fracturing and increase the time for it.

The objective of the claimed utility model is to eliminate the above disadvantages.

The technical result, the achievement of which the present utility model is aimed, is to reduce the time spent on performing multi-stage hydraulic fracturing (MHF) in multilayer wells and increase the efficiency of impact on individual layers by perforating the intervals of the proposed stages of MHF and MHF itself in one run -lifting operation using piercing perforation.

To achieve the technical result, a device is proposed for conducting multi-stage hydraulic fracturing, consisting of a tubing string, on which top selective packer with a through hole, a lower selective packer with a through hole, a pressure shut-off valve, a piercing device are mounted perforating the casing string in the intervals of the planned hydraulic fracturing, and the frac port (hole for hydraulic fracturing fluid injection), under which the perforated nozzle of the tubing string is located.

The essence of the utility model is illustrated in the drawing.

The figure 2 presents a device for conducting a multi-stage hydraulic fracturing, where:

1 - column tubing;

2 - top selective packer;

3 - tail port;

4 - perforated pipe;

5 - lower selective packer;

6 - pressure shut-off valve;

7 - piercing device.

A device for conducting multi-stage hydraulic fracturing includes a tubing string 1, an upper selective packer 2 with a through hole, a hydraulic fluid injection hole (frac port) 3, a perforated nozzle 4 of the tubing string 1, and a lower selective packer 5 s a bore, a pressure shut-off valve 6, a piercing device 7.

The device operates as follows. A device for conducting multi-stage hydraulic fracturing (Fig. 2) is lowered into the well with several productive formations, the piercing device (7) is adjusted to the lower fracturing interval, fluid is pumped through the tubing string, which comes from the frac port (3), activates the top (2) and bottom (5) selective packers. Increasing the pressure in the tubing string at the mouth, the pressure in the interpacker space increases, then the liquid, passing through the holes of the perforated nozzle (4), enters the passageway of the lower selective packer (5), then through the passageways of the pressure shut-off valve (6), into the piercing device (7). The piercing device may be a housing with a piston with a punch inserted into it; under the action of pressure, the fluid through the passageways in the piercing device (7) activates a piston with a punch that perforates the casing. In the next step, depressurizing the pressure in the tubing string (1) at the mouth, the upper (2) and lower (5) selective packers are brought into the transport position, the layout is lowered so that the interpacker space is located opposite the perforated hydraulic fracturing interval. Gradually increasing the pressure in the tubing string (1), the upper (2) and lower (5) selective packers are activated, at the moment when the pressure reaches the value of P ₁ (where P ₁ is the response pressure of the pressure shut-off valve), in the pressure shut-off valve (6 ) there is a overlap of the fluid passageways so that a pressure exceeding the value of P _{1 is} not transmitted to the piercing device (7). After the pressure shut-off valve (6) is activated, the hydraulic fracturing (pumping of fluid and proppant) in this interval is carried out. After the end of the hydraulic fracturing stage, the pressure in the tubing string is relieved, the packers (2.5) go into transport position, and the assembly is re-fitted to the next higher hydraulic fracturing interval.

Consider an example of using the claimed device as an example of two stage hydraulic fracturing. Well X of field M., planned hydraulic fracturing intervals of 3032 m - 3035 m, 3042 m - 3050 m. We make a descent device for multi-stage hydraulic fracturing by geophysical methods to the lower hydraulic fracturing interval (3042-3050 m), so that the piercing hammer is in given interval. Next, with minimal pressure, we pump liquid into the tubing string (1), the liquid passing through the upper selective packer (2) enters the frac port (3), and from there the liquid enters the annular interpacker space thereby activating the upper (2) and lower (5) selective packers, as soon as the packers are activated, the liquid through the perforated pipe (4) enters the pressure shut-off valve (6), and then passes to the piercing device (7). The pressure at the wellhead is increased to P = 200 Atm, at this pressure, the perforating device (7) is triggered and the punches make holes in the casing of the well in the planned interval. The next step is to relieve pressure in the tubing string, after which the selective packers (2), (5) and the piercing device (7) go into the transport position, lower the device by 2 m, so that the perforation interval of 3042-3050 m is in the interpacker space. Further, gradually increasing the pressure at the wellhead in the tubing string, the packers (2), (5) are activated, when the pressure increases to a value of P ₁ = 220 Atm, the pressure shut-off valve (6) is activated, and then the pressure is increased to P = P _{frac reservoir} - approximately 500 Atm; the planned volume of the hydraulic fracturing mixture is injected into a given interval. After pumping the entire planned volume of the hydraulic fracturing mixture, the pressure on the wellhead is relieved, the selective packers (2), (5) and the shut-off valve (6) go into transport position, the entire tubing string is raised to the second hydraulic fracturing interval (3032 m - 3035 m) by 18 m., so that the piercing device was at a depth of 3034 m. After which, increasing the pressure of the liquid in the tubing string, the upper (2) and lower (5) selective packers are activated, the liquid through the frac port (3) enters the perforated pipe (4), from there liquid passing through the shut-off valve pressure (6), enters the piercing device (7). When the pressure reaches P = 200 Atm, the casing is perforated. After that, the pressure at the wellhead is relieved, transferring the packers (2), (5) and the piercing device (7) to the transport mode, lowering the tubing string by 4 m, so that the perforation interval is in the interpacker space. Then, gradually increasing the pressure in the tubing string, the upper (2) and lower (5) selective packers are activated, cutting off this perforated interval (3032 m - 3035 m) from the entire wellbore, at the moment when the pressure reaches P ₁ = 220 Atm, the shut-off valve is triggered pressure (6), which prevents the transmission of pressure to the piercing device (7). Then the pressure is increased to P = P of the _{hydraulic fracturing} - about 500 Atm, hydraulic fracturing is performed (3032-3035 m.) With the injection of the planned volume of the hydraulic fracturing mixture, after injection of the entire volume, the pressure on the well is relieved, transferring selective packers (2), (5 ) and the pressure shut-off valve (6) to the transport position, remove the device from the well. The planned two-stage hydraulic fracturing in the well. X performed in one round trip.

The analysis of patent and scientific and technical literature did not reveal technical solutions with a similar set of essential features, which allows us to conclude that the criterion of "novelty" of the claimed utility model is met.

Claims (1)

A device for conducting a multi-stage hydraulic fracturing, consisting of a tubing string, on which an upper selective packer with a through hole is mounted, a lower selective packer with a through hole, characterized in that a shut-off valve is mounted under the lower selective packer on the tubing string pressure and a piercing device that perforates the casing in the intervals of the planned hydraulic fracturing, and a frac port is installed between the upper and lower packers in the tubing string, under which th nozzle is a perforated tubing string.

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