RU2644361C1 - Method of hydraulic fracturing of a lay in the well - Google Patents

Abstract

FIELD: oil production industry.

SUBSTANCE: invention relates to oil production industry and can be used for hydraulic fracturing. Method for hydraulic fracturing in a well involves perforating channels in the walls of the casing string in the formation interval, lowering of casing string with the packer, landing of the packer above the roof of the perforated productive formation, pumping of the gelled fracturing fluid into the below-packer zone, creating fracturing pressure in the below-packer zone with the formation of a fracture with the subsequent cyclic injection of the gelled liquid with proppant, flushing of a gelled liquid with proppant into the formed fracture, prior to hydraulic fracturing, a test-injection is performed, clamping pressure of rocks is determined, then the fracturing process is cyclically conducted, wherein each cycle of the process consists of five consecutive stages: injection of a gelled liquid of rupture with a viscosity of 400 cps, injection of a gelled liquid with a viscosity of 400 cps with a proppant, flushing of a gelled fracture fluid with a viscosity of 400 cps with a proppant into the fracture crack by injecting a gelled fracture fluid with a viscosity of 40 cPs; stopping pumping for the time of the decline in the supply pressure below the pressure of closing rocks, spouting of spent gelled fluids from the fracture into a vessel through fittings with diameters of 2, 4, 8 mm, at that from the first to the penultimate cycle of the injection and at the 3 stage, the gel liquid with proppant is over-flushed into a crack, and in the last cycle and at the 3 stage, over-flushing of the gelled liquid with proppant into the fracture is performed and the proppant is left the well.

EFFECT: technical result is the simplification of the technology, the increase in the efficiency of the hydraulic fracturing, the increase in the fracture coverage of fractures with increasing their conductivity.

1 cl, 4 dwg

Description

The invention relates to the oil industry and can be used for hydraulic fracturing (hydraulic fracturing).

A known method of hydraulic fracturing in a well (patent RU No. 2564312, IPC E21B 43/267, publ. 09/27/2015, bull. No. 27), including perforation of the walls of the well in the interval of the formation by channels with depth not less than the length of the zone of stress concentration in the rocks from the wellbore wells, lowering the pipe string with the packer so that the lower end of the pipe string is at the level of the formation roof, landing the packer over the roof of the perforated formation, determining the total volume of the gelled fracturing fluid before hydraulic fracturing, injecting the gelled fracturing fluid into the sub-packer zone, creating sub-packer hydraulic fracturing pressure zone and formation of cracks in the formation with their subsequent fixing in the formation by injection of carrier fluid with proppant, holding the well for pressure relief, unpacking and removing the packer from the pipe string from the well.

At the wellhead, a pipe string above the packer at a distance of 10 m is equipped externally with a jet pump. Then the pipe string is lowered into the well and the packer is planted over the roof of the perforated formation. Next, a string of flexible pipes (GT) is lowered into the pipe string so that the lower end of the HT string is located below the end of the pipe string and in the middle of the formation. At the wellhead, the space between the pipe string and the GT string is sealed. The total volume of the gelled fracturing fluid is determined. The total volume of the gelled fracture fluid is divided into two equal parts: the first part is the fracture fluid, the second part is the carrier fluid. A hydraulic column is injected into the sub-packer zone of the first part, the fracture fluid, and the hydraulic fracturing pressure is created in the sub-packer zone with formation of cracks in the formation. Then, cracks in the formation are fixed by injection of the second part of the carrier fluid with proppant, and proppant of smaller and larger fractions is used as proppant. Injection of a carrier fluid with a proppant of a fine fraction of 20/40 mesh and a coarse fraction of 16/40 mesh is carried out simultaneously in a 4: 1 ratio. Moreover, a carrier fluid with a large fraction proppant is pumped through a GT column, and a carrier fluid with a small fraction proppant is pumped through a pipe string with a stepwise increase in the concentration of fine and coarse proppant in a carrier fluid. Withstand pressure relief. Depressurization is made at the wellhead of the space between the pipe string and the GT string. At the wellhead, between the pipe columns and the GT, a sealing ring insert is installed and it is pressed through the pipe string under the action of excessive pressure until the pipe string is hydraulically connected to the jet pump. Produce the development of the reservoir through a jet pump. At the end of the development of the reservoir, the GT column is removed from the pipe string, the packer and the packer with the pipe string are unpacked and removed from the well. The disadvantages of this method are:

- firstly, a complex technology for implementing the method associated with the use of a GT column, as well as with a stepwise increase in the proppant concentration of fine and coarse fractions in the process of fixing a fracture crack;

- secondly, the low efficiency of hydraulic fracturing, due to the fact that they first form a fracture fracture, and then fix it by simultaneous injection of proppants of fine (20/40 mesh) and large (16/40 mesh) fractions in a ratio of 4: 1, which leads to an uneven distribution of proppant in the formation fracture and reduces the throughput of fracturing fractures, restricts the flow of formation fluid into the wellbore;

- thirdly, low coverage of the formation with a hydraulic fracture, since the fracture is opened and fixed by the proppant in only one direction, i.e. in the direction of stress.

A known method of hydraulic fracturing in a well (patent RU No. 2473798, IPC E21B 43/26, publ. 01/27/2013, bull. No. 3), including perforation of the walls of the casing of the well in the interval of the formation by channels with depth not less than the length of the zone of stress concentration in the rocks from the wellbore, lowering the pipe string with the packer, packing the packer over the roof of the perforated reservoir, injecting the fractured gel fluid into the sub-packer zone, creating hydraulic fracturing pressure in the sub-packer zone and pushing the gelled fracturing fluid with proppant into the formed fracture. Before hydraulic fracturing, the pipe string is filled with process fluid and the total volume of the gelled fracturing fluid V _r is determined by calculation, which is divided into two parts, of which 2/3 V _r is the volume of the crosslinked gel, and 1/3 V _r is the linear gel. The hydraulic fracturing process begins with the injection into the well through a string of gelled fracturing fluid pipes — a crosslinked gel with a dynamic viscosity of 150-200 cPa until a fracture fracture forms in the formation. After creating a fracture in the formation, the volume of the crosslinked gel remaining from 2/3 V _{r is} pumped in equal portions in 3-5 cycles with the addition of a proppant fraction of 12-18 mesh with a flow rate of 1.5-2 m ³ / min. Moreover, the proppant is introduced into the crosslinked gel stepwise with increasing concentrations from 200 to 1000 kg / m. Further, without stopping the hydraulic fracturing process, into the well along the pipe string, increasing the flow rate to 2.5-3 m ³ / min, the fracturing fluid is pumped in equal portions in 3-5 cycles - a linear gel with a dynamic viscosity of 30-50 cPa with the addition of proppant fraction 20 -40 mesh with a stepwise increase in concentration from 200 kg / m ³ to 1000 kg / m ³ . After the last portion of the linear gel with proppant is pumped into the pipe string of the well, they are pumped into the formation with process fluid. At the same time, during the delivery process, the flow rate of the process fluid is reduced to 0.5-1 m ³ / min for 1-3 minutes and pumping is resumed again with a flow rate of 2.5-3 m ³ / min until the linear gel with proppant is fully injected into the formation. Then produce exposure for the time required for the drop in injection pressure by 70-80%. Unpack the packer and remove it with the pipe string from the well.

The disadvantages of this method are:

- firstly, the complexity of the technology for implementing the method, associated with an increase in the proppant concentration during crack attachment, with a decrease in the flow rate of the process fluid to 0.5-1 m ³ / min for 1-3 minutes and subsequent resumption of injection with a flow rate of 2.5- 3 m ³ / min until the proppant is fully pushed into the formation;

- secondly, the low efficiency of hydraulic fracturing, due to the fact that they first form a fracture fracture, and then proppant cyclically fasten it, while the final sections of the fractures manage to close by the time they are filled with proppant, resulting in an uneven distribution of proppant in the formation fracture, which reduces the throughput of fracturing fractures and limits the flow of formation fluid into the wellbore;

- thirdly, the low coverage of the formation with hydraulic fractures, since the fracture is opened and fixed by the proppant in only one direction, i.e. in the direction of stress.

- fourthly, the low conductivity of the fracture fracture, since the spent gelled fluid fracture is filtered into the reservoir, clogging its pores.

The technical objectives of the invention are to simplify the technology for implementing the method, increase the efficiency of hydraulic fracturing, increase the coverage of the formation by fracture fractures and increase the conductivity of fracture fractures.

The stated technical problems are solved by the method of hydraulic fracturing — hydraulic fracturing in the well, including perforating the walls of the casing of the well in the reservoir interval by channels, lowering the string of pipes with a packer, planting the packer above the roof of the perforated reservoir, injecting a gelled fracturing fluid into the sub-packer zone, creating a sub-packer zone hydraulic fracturing pressure with the formation of a fracture fracture followed by cyclic injection of the gelled fluid with proppant, pushing the gelled fluid layer into the formed fracture proppant board.

What is new is that before the hydraulic fracturing process is carried out, a test injection is carried out, the closure pressure of the rocks is determined, then the hydraulic fracturing process is carried out cyclically, and each cycle consists of five successive stages: injection of a gelled fracturing fluid with a viscosity of 400 cps; injection of gelled fracturing fluid with a viscosity of 400 cps with proppant; selling gelled fracturing fluid with a viscosity of 400 cps with proppant into the fracture fracture by injection of gelled fracturing fluid with a viscosity of 40 cps; stopping the injection during the pressure drop of the selling pressure below the closing pressure of the rocks; outflow of spent gelled liquids from the fracture gap into the container through fittings with diameters of 2, 4, 8 mm, and from the first to the penultimate injection cycle at the 3rd stage, the gelled liquid with proppant is resold into the crack, and in the last cycle at the 3rd stage undersupply of gelled proppant fluid into the fracture fracture with proppant left in the wellbore.

In FIG. 1 schematically shows the proposed hydraulic fracturing method.

In FIG. 2, 3 and 4 schematically and sequentially depicted cycles of the implementation of the hydraulic fracturing method.

The proposed method of hydraulic fracturing in a well is as follows.

The hydraulic fracturing method in well 1 (see FIG. 1) includes perforating the walls of the casing of the well 1 with channels 2 in any known manner, for example, as described in patent RU No. 2358100, IPC E21B 43/26, publ. 06/10/2009, in bull. No. 16.

A pipe string 3 is lowered into a well 1 into a hydraulic fracturing zone, for example a tubing string 73 mm in diameter with a packer 4 so that the packer is 10 m above the roof 5 of formation 6 to be framed, and the lower end of the pipe string 3 - 3 m above the roof 5 of layer 6 in order to completely exit proppant from the pipe string 3 during hydraulic fracturing.

Packer 4 of any known construction is planted in well 1. Thus, annulus 7 of well 1 is sealed to protect the walls of the casing 1 from the effects of high pressures arising during hydraulic fracturing.

Previously, before the hydraulic fracturing process, a test injection is carried out to determine the closure pressure of rocks P _c . To conduct a test injection through a pipe string 3, a gelled fracturing fluid (viscosity 400 cPs) is injected without adding proppant while recording pressure values in the process of rock fracturing. Interpretation of the pressure values obtained by recording the pressures during the test injection is carried out, and the closure pressure of the fracture crack is determined, for example, P _c = 21.0 MPa.

Two types of gelled fracturing fluid with viscosities of 40 and 400 cps are prepared by any known method.

Begin the hydraulic fracturing process. In the process of hydraulic fracturing, a gelled fluid with proppant is cyclically injected, and each cycle consists of five successive stages:

Stage 1 - injection of gelled fracturing fluid with a viscosity of 400 cps.

Stage 2 - injection of gelled fracturing fluid with a viscosity of 400 cps with proppant.

Stage 3 - selling gelled fracture fluid with a viscosity of 400 cps with the addition of proppant to the fracture by injection of gelated fracture fluid with a viscosity of 40 cps.

Stage 4 - stopping the injection for the duration of the drop in the selling pressure below the rock closing pressure, i.e. technological pause for the pressure drop in the pipe string from the pressure of the push to the pressure below the pressure of the closure of rocks. This stage is necessary for the pressure to drop below the closure pressure of the rocks P _s , determined according to the test injection data, as well as for the preliminary fixation of the proppant in the fracture fracture.

The efficiency of hydraulic fracturing is increased, since proppant does not cyclically fill one crack, while, on the contrary, the crack is fixed in one stage and the proppant is pre-fixed in the fracture by performing a technological pause to drop the pressure in the pipe string from the pressure of the pump to the pressure below Closing pressure of rocks.

Stage 5 - the discharge of spent gelled liquids from a fracture gap into a container through fittings with diameters of 2, 4, 8 mm.

This stage in the process of implementing the proposed method is necessary for reinforcing proppant in the fracture and cleaning the bottom-hole formation zone (BHP) from the remnants of the gelled fluid, which allows to increase the conductivity of the formed fracture cracks and to prevent clogging of the pores of the formation with spent gelled fracture fluids. Thus, the maximum cleansing of the fracture fixed by the proppant occurs from the spent gelled fracture fluids, moreover, after the formation of each crack (after each cycle).

From the first to the penultimate cycle of the hydraulic fracturing process, at the 3rd stage, the gelled fluid with proppant is resold to the fracture, and in the last cycle at the 3rd stage, the gelled gel with proppant is under-sold into the fracture, leaving proppant in the wellbore.

Selling gelled liquid with proppant to the crack allows, after the first cycle of crack formation and its fixing with proppant, to redistribute stresses in the bottomhole zone of radius R in order to change the azimuthal propagation of the newly formed fracture cracks.

The proposed hydraulic fracturing method is implemented in several cycles, the meaning of which is that after the first cycle is completed, stresses are redistributed in the bottomhole zone and the cracks formed and fixed during subsequent cycles change the propagation azimuth, which allows to increase the coverage of the formation by fracture fractures.

For example, hydraulic fracturing is performed in three cycles.

The first cycle of hydraulic fracturing (see Fig. 1 and 2).

Stage 1 Open the valve 8 and using a pump unit 9 from the tank 10, the gelled fracturing fluid with a viscosity of 400 cPs is injected into the formation 6 through the pipe string 3 through the perforation channels 2, for example, at a rate of 1.2 m ³ / min until the formation rock is broken 6 and the formation of cracks 11 ', as evidenced by a drop in injection pressure and an increase in injectivity of the formation 6.

For example, when the pressure reached 25 MPa due to the formation of a crack 11 ', the injection pressure of the crosslinked gel dropped by 20-25%, i.e. up to 20 MPa, while the injectivity of the formation 6 increased by 25-30%, for example, from 1.2 to 1.6 m ³ / min, and during the formation of a crack 11 'a gel-like fracturing fluid with viscosity was injected into the pipe string 3 of well 1 400 cps in the volume V _cg1 = 4.0 m ³ .

2 stage. They make an injection through a column of pipes 3 of a gelled fracturing fluid with a viscosity of 400 cps with a proppant of 12 ', for example, a fraction of 20/40 mesh with a concentration of ρ = 600 kg / m ³ . To do this, with the open valve 8 using the pump unit 9, the gelled fracturing fluid is injected with a viscosity of 400 cPs from the tank 10 with proppant weighing m = V _cr1 ⋅ρ = 4.0 m ³ ⋅ 600 kg / m ³ = 2400 kg = 2.4 t from tank 13.

3 stage. A gelled fracturing fluid with a viscosity of 400 cPs was added with the addition of proppant 12 'to the fracture of the fracture 11' with a view to securing it. For reselling at this stage, the volume of the gelled fracturing fluid is taken equal to the volume of the pipe string 3 increased by 2 m ³ , for example, V _n1 = 3.5 m ³ +2 m ³ = 5.5 m ³ , i.e. 2 m ^{3 of} gelled liquid is used for reselling.

Thus, with the open valve 8 from the tank 14 using the pump unit 9, they are pumped through a pipe string 3 of a gelled fracturing fluid with a viscosity of 40 cPs, for example, at a pressure of P _p = 30.0 MPa in a volume of V _p1 = 5.5 m ³ and they resell the gelled liquid with proppant 12 'from the pipe string 3 through the channels 2 of the well 1 into the crack 11' so that the PPP in the radius R (see Fig. 1), for example 2 m, remains open (not fixed by the proppant 12 ').

The reselling of the gelled liquid with proppant 12 'to the crack 11' allows, after the first cycle of formation of the crack 11 'and fixing it with the proppant 12', to redistribute the stresses in the BCP 6 with radius R in order to change the azimuthal propagation of the newly formed fracture cracks 11 '' and 11 '' '.

4 stage. Stop pumping (turn off the pump unit 9 and close the valve 8). They withstand a technological pause for the time of the drop in the pressure of the push P _p = 30.0 MPa below the closure pressure of the rocks P _c = 21 MPa, determined according to the test injection, for example, for 10 minutes

This stage is necessary for the pressure of the selling to drop below the pressure of the closure of rocks and the preliminary fixing of the proppant in the fracture 11 '.

5 stage. Spilling the spent gelled fracturing liquids from the fracture 11 'through the fittings 15 with diameters of 2, 4, 8 mm. For this, at a pressure lower than the closing pressure of the crack 11 '(P _c = 21 MPa), for example, at a pressure of 20 MPa, open the valve 16 (with the valve closed 8) and discharge the spent gelled fracturing liquids from the crack 11' through the pipe string 3 through the open the valve 16, the fittings 15 in the tank 17 to reduce the pressure to atmospheric. The spout time corresponds to the time required for the pressure to drop to atmospheric pressure, for example, for 5 minutes.

The second cycle of hydraulic fracturing (see Fig. 1 and 3).

Stage 1 Open the valve 8 and using the pump unit 9 from the tank 10 make an injection of the gelled fracturing fluid, which is used as a crosslinked gel with a viscosity of 400 cPs, into the formation 6 along the pipe string 3 through perforation channels 2, for example, with a flow rate of 1.2 m ³ / min before reaching the rock break in the formation 6 and the formation of an 11 '' crack (see Figs. 1 and 2), as evidenced by a drop in injection pressure and an increase in the injectivity of the formation 6. For example, when a pressure of 27 MPa was reached due to the formation of an 11 '' crack, crosslinked gel injection pressure n and 20-25%, i.e. up to 21 MPa, while the injectivity of formation 6 increased by 25-30%, for example, from 1.2 to 1.6 m ³ / min, and during the formation of an 11 '' crack a gelled fracturing fluid was pumped into the pipe string 3 of well 1 viscosity 400 cps in a volume of V _sg2 = 4.5 m ³ .

2 stage. They make an injection through a column of pipes 3 of a gelled fracturing fluid with a viscosity of 400 cPs with a 12 '' proppant, for example, a 20/40 mesh fraction with a concentration of ρ = 600 kg / m ³ . To do this, a valve opening 8 through the pump set 9 produce download gelled fluid viscosity 400 cps gap from the container 10 with a proppant mass m = V _a2 ⋅ρ = 4,5 m ³ ⋅600 kg / m ³ = 2700 kg = 2.7 t. from tank 13.

3 stage. A gelled fracture fluid with a viscosity of 400 cPs was added with the addition of 12 "proppant to the 11" fracture fracture in order to fix it. For reselling at this stage, the volume of the gelled fracturing fluid is taken equal to the volume of the pipe string 3 increased by 2 m ³ , for example, V _p1 = 3.5 m ³ +2 m ³ = 5.5 m ³ .

With the valve open 8 from the tank 14, using a pump unit 9, 40 cPs viscosity gel rupture fluid is injected through the pipe string 3, for example, at a pressure of P _p = 30.0 MPa in a volume of V _p2 = 5.5 m ³ and re-selling gelled liquid with a proppant 12 '' from the pipe string 3 through the channels 2 of the well 1 into the fracture 11 '' so that the PPP in the radius R, for example 2 m, remains open (not fixed by the proppant 12 '').

The reselling of the gelled fluid with proppant 12 ″ into the crack 11 ″ allows, after the first cycle of formation of the crack 11 ″ and fixing it with the proppant 12 ″, to redistribute the stresses in the BCP 6 of radius R in order to change the azimuthal propagation of the newly formed 11 ″ fracture cracks.

4 stage. Stop pumping (turn off the pump unit 9 and close the valve 8). They withstand a technological pause for the time of the drop in the pressure of the push P _p = 30.0 MPa below the closure pressure of the rocks P _c = 21 MPa, determined according to the test injection, for example, for 10 minutes

This stage is necessary for the pressure to drop below the closure pressure of the rocks and the preliminary fixation of the proppant in the 11 '' fracture.

5 stage. Spilled spent gelled fracturing liquids from an 11 '' fracture crack through fittings 15 with diameters of 2, 4, and 8 mm. To do this, at a pressure below the crack closure pressure of 11 '' (P _c = 21 MPa), for example, at a pressure of 20 MPa, open the valve 16 (with the valve closed 8) and discharge the spent gelled fracturing fluids (viscosity 40 and 400 cPs) from the crack 11 '' along the pipe string 3 through an open gate valve 16, fittings 15 into a container 17 until the pressure drops to atmospheric pressure. The spout time corresponds to the time required for the pressure to drop to atmospheric pressure, for example, for 5 minutes.

The third cycle of hydraulic fracturing (see Fig. 1 and 4).

Stage 1 Open the valve 8 and using a pump unit 9 from the tank 10, the gelled fracturing fluid with a viscosity of 400 cPs is injected into the formation 6 through the pipe string 3 through the perforation channels 2, for example, at a rate of 1.2 m ³ / min until the formation rock is broken 6 and formation of an 11 "″ crack (see Figs. 1 and 2), as evidenced by a drop in injection pressure and an increase in injectivity of formation 6. For example, when a pressure of 29 MPa was reached due to the formation of an 11 ″ ″ crack, the injection pressure of the crosslinked gel dropped by 20 -25%, i.e. up to 23 MPa, while the injectivity of formation 6 increased by 25-30%, for example, from 1.2 to 1.6 m ³ / min, and during the formation of a 11 '' crack in the pipe string 3 of well 1, a gel-like liquid was pumped a fracture with a viscosity of 400 cps in a volume of M _cg3 = 5.0 m ³ .

2 stage. They make an injection through a column of pipes 3 of a gelled fracturing fluid with a viscosity of 400 cPs with a 12 '' proppant, for example, a 20/40 mesh fraction with a concentration of ρ = 600 kg / m ³ . To do this, with the open valve 8 using the pump unit 9, the gelled fracturing fluid is injected with a viscosity of 400 cPs from the tank 10 with proppant weighing m = V _sg3 ⋅ρ = 5.0 m ³ ⋅600 kg / m ³ = 3000 kg = 3.0 t from tank 13.

3 stage. A gelled fracturing fluid with a viscosity of 400 cPs was added with the addition of proppant 12 ″ ″ into the 11 ″ ″ fracture fracture in order to fix it. For the implementation of undersupply at this stage, the volume of the gelled fracturing fluid is taken equal to the volume of the pipe string 3, i.e. V _p3 = 3.5 m ³ , with the aim of leaving in the well under the pipe string 3 proppant "glass".

With the valve open 8 from the tank 14, using the pump unit 9, 40 gps of the gelled fracturing fluid is injected through the pipe string 3 with a viscosity of 40 cPs, for example, at a pressure of P _p = 30.0 MPa in a volume of V _p3 = 3.5 m ³ and undersupply gelled fluid with a proppant 12 ’’ from the pipe string 3 through the channels 2 of the well 1 into the 11 ″ трещ fracture, while the proppant 12 ″ ’remains in the wellbore 1 below the lower end of the pipe string 3 (not shown in Fig. 1) .

4 stage. Download stop, i.e. turn off the pumping unit 9 (see Figs. 1 and 4) and close the valve 8. Maintain a technological pause for the time of the decrease in the squeezing pressure P _p = 30.0 MPa below the closure pressure of the rocks P _c = 21 MPa, determined according to the test injection for example for 10 minutes

This stage is necessary for the pressure to drop below the closure pressure of the rocks and the preliminary fixation of the proppant in the 11 '' fracture.

5 stage. Spilled spent gelled fracturing liquids from an 11 '' 'fracture fracture through fittings 15 with diameters of 2, 4, and 8 mm.

For this, at a pressure below the crack closure pressure of 11 '' (P _s = 21 MPa), for example, at a pressure of 20 MPa, open the valve 16 (with the valve closed 8) and discharge the spent gelled fracturing fluids (viscosity 40 and 400 cPs) from cracks 11 '''along the pipe string 3 through an open valve 16, fittings 15 into a container 17 until the pressure drops to atmospheric pressure. The spout time corresponds to the time required for the pressure to drop to atmospheric pressure, for example, for 5 minutes.

Next, unpack packer 4, i.e. the annular space 7 of well 1 is depressurized. Pipe string 3 with packer 4 is removed from well 1. The hydraulic fracturing process is completed. The remaining proppant in the wellbore is removed during further flushing or development of the well 1.

The proposed method is simple to implement, since it does not require an increase in proppant concentration in the process of hydraulic fracturing, and a decrease and increase in the flow rate of the gelled fracturing fluid during the injection and delivery.

The proposed hydraulic fracturing method is implemented in several cycles, the meaning of which is that after the first and subsequent cycles are completed, stress redistribution occurs in the bottomhole formation zone, which leads to a change in the azimuth of the propagation of cracks with their subsequent consolidation, which allows to increase the coverage of the formation by fracture fractures.

The proposed method of hydraulic fracturing in the well allows:

- simplify the implementation of the method;

- increase the efficiency of hydraulic fracturing;

- increase the coverage of the formation by fracture cracks;

- increase the conductivity of the fracture rupture.

Claims (1)

The method of hydraulic fracturing - hydraulic fracturing in a well, including perforating the walls of the casing of the well in the reservoir interval by channels, lowering the string of pipes with a packer, landing the packer over the roof of the perforated reservoir, injecting fractured gel fluid into the sub-packer zone, creating hydraulic fracturing pressure in the sub-packer zone to form rupture cracks followed by cyclic injection of the gelled liquid with proppant, pushing the gelled liquid layer with proppant into the formed crack, characterized in that before the hydraulic fracturing process, a test injection is carried out, the closure pressure of the rocks is determined, then the hydraulic fracturing process is carried out cyclically, and each cycle consists of five successive stages: injection of the gelled fracturing fluid with a viscosity of 400 cPs; injection of gelled fracturing fluid with a viscosity of 400 cps with proppant; selling gelled fracturing fluid with a viscosity of 400 cps with proppant into the fracture fracture by injection of gelled fracturing fluid with a viscosity of 40 cps; stopping the injection during the pressure drop of the selling pressure below the closing pressure of the rocks; outflow of spent gelled liquids from the fracture gap into the container through fittings with diameters of 2, 4, 8 mm, and from the first to the penultimate injection cycle at the 3rd stage, the gelled liquid with proppant is resold into the crack, and in the last cycle at the 3rd stage undersupply of gelled proppant fluid into the fracture fracture with proppant left in the wellbore.

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