Fracture height control method for transforming thin oil and gas reservoir by using foam floating particles

Abstract

The invention relates to the technical field of hydraulic fracturing reservoir transformation, in particular to a fracture height control method for thin-layer oil and gas reservoir transformation through foam floating particles. The invention discloses a fracture height control method for transforming a thin oil and gas reservoir by using foam floating particles. The method comprises the following steps: selecting the particle size of the foam floating particles according to reservoir rock mechanical parameters; selecting the types of foam floating particles according to the properties of the fracturing fluid; each foam floating particle is composed of an inner foam particle and an outer covering film; calculating the total amount of foam floating particles according to the crack size; and selecting a construction pumping program according to the reservoir type. According to the method, the phenomenon that the fracture height is out of control due to the fact that the shielding capacity of an interlayer is insufficient when a thin oil and gas reservoir is fractured in the past is solved, the fracture height can be effectively controlled in the thin layer, meanwhile, a certain supporting effect is achieved, full transformation of the reservoir is achieved, and therefore the oil and gas yield is greatly increased.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic fracturing reservoir transformation, and in particular to a fracture height control method for transforming a thin oil and gas reservoir by utilizing foam floating particles. Background Art

[0002] With the reduction and depletion of conventional oil and gas resources, unconventional oil and gas resources such as coalbed methane and tight oil and gas have gradually become the main battlefield for oil and gas development in my country. The economic development of unconventional oil and gas resources must rely on hydraulic fracturing technology, which uses a ground high-pressure pump group to pump fracturing fluid and proppant into the reservoir to form one or more high-conductivity fractures with a certain geometric size, increasing the seepage channel and storage space of oil and gas. Improving the fracturing effect and expanding the reservoir transformation volume are of great significance to increasing the oil and gas production of a single well.

[0003] However, in the actual fracturing process, we often encounter situations such as small oil and gas layers, thin interlayers, or reservoir-interlayer rock mechanical properties that are not obviously different. The barrier layer has insufficient shielding capacity, which makes it difficult to control the height of the hydraulic fracture and penetrate the layer. The reservoir cannot be fully transformed, affecting the fracturing effect. Sometimes, when the aquifer is close to the reservoir, it will cause inter-formation fluid crossflow, and the water content of a single well is too high, reducing economic benefits. How to design fracturing methods and control the height of the fracture is currently a key issue restricting the improvement of single well recovery. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides a fracture height control method for transforming thin oil and gas reservoirs by using foam floating particles.

[0005] The technical solution of the present invention is: A fracture height control method for thin oil and gas reservoir reconstruction using foam floating particles is as follows: Select the size of foam floating particles according to reservoir rock mechanics parameters; The type of foam floating particles is selected according to the properties of the fracturing fluid; the foam floating particles are composed of internal foam particles and external coatings; Calculate the total amount of foam floating particles according to the crack size; the calculation formula is: Q=Q 1 +Q 2 = H×L×W×[α+η / (1-η)]×n×(γ+1) Where: Q is the total amount of foam floating particles, m 3 ;Q 1 The particle size is d 1 Amount of foam floating particles, m 3 ;Q 2 The particle size is d 2 Amount of foam floating particles, m3 , d 2 >d 1 ; H is the designed support joint height, m; L is the designed support joint length, m; W is the designed support joint width, m; α is the percentage of the volume of foam floating particles filling the cracks to the total volume of the cracks, 10%~30%; η is the degree of closed cracks, %; n is the number of fracturing stages, dimensionless; γ is the loss rate of foam floating particles, %; Select the construction pumping procedure according to the reservoir type.

[0006] The selection rule of the foam floating particle size is: If the ratio of the minimum horizontal principal stress of the interlayer to the reservoir is 0.68-1.22, the ratio of the friction coefficient of the interlayer to the reservoir is 0.29-1.43, and the ratio of the tensile strength of the interlayer to the reservoir is 0.17-5.1, low-viscosity fracturing fluid and medium-viscosity fracturing fluid are used for fracturing construction; for low-viscosity fracturing fluid, the particle size d is selected. 1 The foam floating particles are 420μm~212μm; for medium viscosity fracturing fluid, the particle size d 2 Foam floating particles of 590μm~297μm; If the ratio of the minimum horizontal principal stress of the interlayer to the reservoir is 1.22-1.46, the ratio of the friction coefficient of the interlayer to the reservoir is 1.43-1.85, and the ratio of the tensile strength of the interlayer to the reservoir is 5.1-11.3, medium-viscosity fracturing fluid and high-viscosity fracturing fluid are used for fracturing construction; for medium-viscosity fracturing fluid, the particle size d is selected. 1 The foam floating particles are 178μm~150μm; for high viscosity fracturing fluid, the particle size d 2 The foam floating particles are 420μm~212μm.

[0007] The selection rules of the foam floating particle types are: (1) For low-viscosity fracturing fluid, the foam floating particles are polyamide foam floating particles with a density of 0.16 g / cm 3 ~0.51g / cm 3 The internal foam particles of the polyamide foam floating particles are polyamide foam particles with a density of 0.05g / cm 3 ~0.25g / cm 3 , particle size is 120μm-560μm, operating temperature range is 40℃~150℃, compressive strength is 1MPa~2MPa; (2) For medium viscosity fracturing fluid, the foam floating particles are selected from silica gel foam floating particles, with a density of 0.33g / cm 3 ~0.74g / cm 3 The internal foam particles of the silica gel foam floating particles are silica gel foam particles with a density of 0.12g / cm3 ~0.45g / cm 3 , particle size is 120μm-560μm, operating temperature range is 50℃~250℃, compressive strength is 1MPa~2MPa; (3) For high-viscosity fracturing fluid, polytetrafluoroethylene foam floating particles are selected as foam floating particles, with a density of 0.57g / cm 3 ~0.95g / cm 3 The internal foam particles of the polytetrafluoroethylene foam floating particles are polytetrafluoroethylene foam particles with a density of 0.3g / cm 3 ~0.65g / cm 3 , particle size is 120μm-560μm, operating temperature range is 200℃~260℃, compressive strength is 2MPa~4MPa; The external coating is phenolic epoxy resin, and its density is 1.18g / cm 3 ~1.25g / cm 3 The operating temperature range is 10℃~180℃, and the compressive strength is 100MPa~250MPa.

[0008] The preparation method of the foam floating particles is: The internal foam particles are completely immersed in the liquid external coating and mixed evenly, and individual internal foam particles are taken out and separated, and the individual internal foam particles are evenly wrapped by the external coating; then, they are heated and cured and allowed to stand to finally obtain foam floating particles.

[0009] 1. If the reservoir is a tight sandstone reservoir and the sand-carrying fluid is non-viscous fracturing, the specific construction pumping procedure is as follows: (1-1) Viscosity is ν 1 Add 20% Q 1 ~100%Q 1 The particle size is d 1 The foam floating particles are discharged at a volume of 1m 3 / min~8m 3 / min into the wellbore; (1-2) Viscosity is ν 1 Add 50% Q 1 ~80%Q 1 The particle size is d 1 The foam floating particles are discharged at a volume of 2m 3 / min~10m 3 / min into the wellbore; or 2 Add Q to the sand-carrying fluid 2 The particle size is d 2 The foam floating particles are discharged at a volume of 2m 3 / min~15m 3 / min into the wellbore; (1-3) With a displacement of 1m 3 / min~12m 3 The displacement fluid is injected at a rate of / min to complete the controlled fracture high pressure fracturing construction.

[0010] 2. If the reservoir is a tight sandstone reservoir and the sand-carrying fluid is viscous fracturing, the specific construction pumping procedure is as follows: (2-1) Viscosity ν 1 Add 20% Q 1 ~100%Q 1 The particle size is d 1 The foam floating particles are discharged at a volume of 1m 3 / min~8m 3 / min into the wellbore; (2-2) Viscosity is ν 1 Add 50% Q 1 ~80%Q 1 The particle size is d 1 The foam floating particles are discharged at a volume of 2m 3 / min~10m 3 / min into the wellbore; (2-3) Viscosity is ν 2 Add Q to the sand-carrying fluid 2 The particle size is d 2 The foam floating particles are discharged at a volume of 2m 3 / min~15m 3 / min into the wellbore; (2-4) With a displacement of 1m 3 / min~12m 3 Inject displacement fluid at a rate of / min to complete the controlled fracture high-pressure fracturing operation; Among them, viscosity ν 1 ≤Viscosityν 2 .

[0011] 3. If the reservoir is a carbonate reservoir, the specific construction pumping procedure is as follows: (3-1) Add 20% Q to the preacid 1 ~40%Q 1 The particle size is d 1 The foam floating particles are discharged at a volume of 1m 3 / min~5m 3 / min into the wellbore; (3-2) Viscosity is ν 1 Add 40% Q 1~70%Q 1 The particle size is d 1 The foam floating particles are discharged at a volume of 1m 3 / min~8m 3 / min into the wellbore; (3-3) Viscosity is ν 2 Add Q to the sand-carrying fluid 2 The particle size is d 2 The foam floating particles are discharged at a volume of 2m 3 / min~12m 3 / min into the wellbore; (3-4) With a displacement of 1m 3 / min~10m 3 The displacement fluid is injected at a rate of / min to complete the controlled fracture high pressure fracturing construction.

[0012] 4. If the reservoir is a coal rock reservoir, the specific construction pumping procedure is as follows: (4-1) The viscosity is ν 1 Add 20% Q 1 ~50%Q 1 The particle size is d 1 The foam floating particles are discharged at a volume of 1m 3 / min~6m 3 / min into the wellbore; (4-2) Viscosity is ν 2 Add 10% Q 1 ~20%Q 1 The particle size is d 1 The foam floating particles are discharged at a volume of 3m 3 / min~15m 3 / min into the wellbore; (4-3) Viscosity is ν 2 Add 20% Q 2 ~40%Q 2 The particle size is d 2 The foam floating particles are discharged at a volume of 2m 3 / min~10m 3 / min into the wellbore; (4-4) Repeat steps (4-2) and (4-3) 3 to 5 times; (4-5) With a displacement of 1m 3 / min~8m 3 The displacement fluid is injected at a rate of / min to complete the controlled fracture high pressure fracturing construction.

[0013] The technical effects of the present invention are: (1) The present invention solves the problem of uncontrolled fracture height caused by insufficient barrier shielding capacity during fracturing of thin oil and gas reservoirs in the past. It can effectively control the fracture height within the thin layer and play a certain supporting role, thereby achieving full transformation of the reservoir and significantly increasing oil and gas production. (2) The foam floating particles proposed in the present invention can be applied to unconventional oil and gas reservoirs with various barrier types and different reservoir thicknesses, and have a wide range of applications; (3) The foam floating particles proposed in the present invention are cheap, easy to obtain, have low production costs, are chemically stable, and will not react with fracturing fluid and reservoir fluid. The type of foam floating particles can be selected according to the properties of the fracturing fluid, without affecting the selection of fracturing fluid and proppant materials during fracturing construction design. DETAILED DESCRIPTION

[0014] Specific experimental case 1--Dense sandstone in a block of Yichuan The effective thickness of the reservoir is 2.5m; the ratios of the mechanical parameters of the interlayer and the reservoir rock are: the ratio of the minimum horizontal principal stress is 0.96, the ratio of the friction coefficient is 0.57, and the ratio of the tensile strength is 3.9; the geometric dimensions of the fracturing cracks in the reservoir are: the designed support joint height H is 2.5m, the designed support joint length L is 260m, and the designed support joint width W is 7.5mm.

[0015] A fracture height control method for thin oil and gas reservoir reconstruction using foam floating particles is as follows.

[0016] Step 1: Select low-viscosity and medium-viscosity fracturing fluids for fracturing according to the ratio of the rock mechanical parameters of the interlayer and the reservoir; for low-viscosity fracturing fluids, select the particle size d 1 The foam floating particles are 420μm~212μm (40 / 70 mesh); for medium viscosity fracturing fluid, the particle size d 2 The foam floating particles are 590μm~297μm (30 / 50 mesh); among them, the viscosity of low-viscosity fracturing fluid is between 5mPa∙s~50 mPa∙s; the viscosity of medium-viscosity fracturing fluid is between 50mPa∙s~150 mPa∙s.

[0017] Step 2: For low-viscosity fracturing fluid, select polyamide foam floating particles; for medium-viscosity fracturing fluid, select silicone foam floating particles.

[0018] Step 3: Preparation of foam floating particles: Polyamide foam particles (density 0.15 g / cm 3 , particle size 182μm-390μm) and silica foam particles (density 0.3g / cm 3, particle size 267μm-560μm) are completely immersed in the liquid external coating (phenolic epoxy resin) and mixed evenly, and the single internal foam particles are taken out and separated, and the single internal foam particles are evenly wrapped by the phenolic epoxy resin; then put into a 150℃ oven, heat and cure for 40 minutes, take out and stand for 80 minutes after curing, and obtain foam floating particles; then use a sieve to sort out foam floating particles of different particle sizes; the density of the prepared polyamide foam floating particles is 0.34g / cm 3 , silica gel foam floating particle density 0.56g / cm 3 .

[0019] Step 4: Calculate the total amount of foam floating particles according to the crack size; The number of fracturing stages n is 1, the loss rate of foam floating particles γ is 15%, the percentage of the volume of foam floating particles filling the cracks to the total volume of the cracks α is 20%, and the degree of closed cracks η is 8%. 1 The amount of foam floating particles Q 1 60%Q, particle size d 2 The amount of foam floating particles Q 2 is 40%Q, calculated according to the formula: particle size d 1 Polyamide foam floating particles Q of 420μm~212μm (40 / 70 mesh) 1 0.965m 3 , particle size d 2 590μm~297μm (30 / 50 mesh) silica foam floating particles Q 2 0.644m 3 .

[0020] Step 5: Select the construction pumping procedure according to the reservoir type; Since a block in Yichuan is dense sandstone and uses sand-carrying fluid viscous fracturing, the specific construction pumping procedure is as follows: (1) Add 0.2895 mPa∙s to the pre-liquid with a viscosity of 15 mPa∙s 3 The particle size is 420μm~212μm (40 / 70 mesh) polyamide foam floating particles, with a displacement of 3.5m 3 / min into the wellbore; (2) Add 0.6755 m3 of 3 The particle size is 420μm~212μm (40 / 70 mesh) polyamide foam floating particles, with a displacement of 6.5m 3 / min into the wellbore; (3) Add 0.644 m3 of 3The particle size is 590μm~297μm (30 / 50 mesh) of silica gel foam floating particles, with a displacement of 8m 3 / min into the wellbore; (4) With a displacement of 5m 3 The displacement fluid is injected at a rate of / min to complete the controlled fracture high pressure fracturing construction.

[0021] After the construction was completed, the actual support joint height of the crack was monitored and the actual support joint height was 2.87m, which was only 14.8% higher than the designed support joint height H.

[0022] Specific experimental case 2--carbonate reservoir in a block of Yan'an gas field The effective thickness of the reservoir is 3.8m, and the ratios of the mechanical parameters of the interlayer and the reservoir rock are: the ratio of the minimum horizontal principal stress is 1.31, the ratio of the friction coefficient is 1.55, and the ratio of the tensile strength is 5.6; the geometric dimensions of the fracturing cracks in the reservoir are: the designed support joint height is 3.8m, the designed support joint length is 270m, and the designed support joint width is 7mm.

[0023] A fracture height control method for thin oil and gas reservoir reconstruction using foam floating particles is as follows.

[0024] Step 1: Select medium-viscosity and high-viscosity fracturing fluids for fracturing according to the ratio of the mechanical parameters of the interlayer and the reservoir rock; for medium-viscosity fracturing fluids, select the particle size d 1 The foam floating particles are 178μm~150μm (80 / 100 mesh). For high viscosity fracturing fluid, the particle size d 2 The foam floating particles are 420μm~212μm (40 / 70 mesh); among them, the viscosity of medium-viscosity fracturing fluid is between 50mPa∙s~150 mPa∙s, and the viscosity of high-viscosity fracturing fluid is between 150mPa∙s~300 mPa∙s.

[0025] Step 2: For medium viscosity fracturing fluid, select silica gel foam floating particles; for high viscosity fracturing fluid, select polytetrafluoroethylene foam floating particles.

[0026] Step 3: Preparation of foam floating particles: Silica gel foam particles (density 0.3g / cm 3 , particle size 148μm-120μm) and polytetrafluoroethylene foam particles (density 0.49g / cm 3, particle size 182μm-390μm) is completely immersed in the liquid external coating (phenolic epoxy resin) and mixed evenly, and the individual internal foam particles are taken out and separated. The individual internal foam particles are evenly wrapped by the phenolic epoxy resin; then put them in a 170℃ oven and heat and cure for 30 minutes. After curing, take them out and let them stand for 90 minutes to obtain foam floating particles; then use a sieve to sort out foam floating particles of different particle sizes. The density of the prepared silica foam floating particles is 0.58g / cm 3 The floating particle density of polytetrafluoroethylene foam is 0.8g / cm 3 .

[0027] Step 4: Calculate the total amount of foam floating particles according to the crack size; The number of fracturing stages n is 1, the loss rate of foam floating particles γ is 20%, the percentage of the volume of foam floating particles filling the cracks to the total volume of the cracks α is 28%, and the degree of closed cracks η is 12%. 1 The amount of foam floating particles Q 1 The particle size is 65% Q and d 2 The amount of foam floating particles Q 2 is 35%Q, calculated according to the formula: particle size d 1 The amount of silica gel foam floating particles Q is 178μm~150μm (80 / 100 mesh) 1 2.33m 3 , particle size d 2 The amount of polytetrafluoroethylene foam floating particles Q is 420μm~212μm (40 / 70 mesh) 2 1.26m 3 .

[0028] Step 5: Select the construction pumping procedure according to the reservoir type; Due to the carbonate reservoir in a block of Yan'an gas field, the construction pumping procedure is as follows: (1) Add 0.932m 3 The particle size is 178μm~150μm (80 / 100 mesh) silica gel foam floating particles, with a displacement of 1.5m 3 / min into the wellbore; (2) Add 1.398 mPa∙s to the pre-liquid with a viscosity of 80 mPa∙s 3 The particle size is 178μm~150μm (80 / 100 mesh) silica gel foam floating particles, with a displacement of 2.5m 3 / min into the wellbore; (3) Add 1.26 mPa∙s to the sand-carrying fluid with a viscosity of 160 mPa∙s. 3The particle size is 420μm~212μm (40 / 70 mesh) of polytetrafluoroethylene foam floating particles, with a displacement of 3.5m 3 / min into the wellbore; (4) With a displacement of 2m 3 The displacement fluid is injected at a rate of / min to complete the controlled fracture high-pressure fracturing construction.

[0029] After the construction was completed, the actual support joint height of the crack was monitored and the actual support joint height was 4.2m, which was only 10.5% higher than the designed support joint height H.

Claims

1. A method for controlling fracture height by using foam floating particles to transform thin oil and gas reservoirs, characterized in that: Here’s how: Select the size of foam floating particles according to reservoir rock mechanics parameters; The type of foam floating particles is selected according to the properties of the fracturing fluid; the foam floating particles are composed of internal foam particles and external coatings; Calculate the total amount of foam floating particles according to the crack size; the calculation formula is: Q=Q1+Q2= H×L×W×[α+η / (1-η)]×n×(γ+1) Where: Q is the total amount of foam floating particles, m 3 ; Q1 is the amount of foam floating particles with a particle size of d1, m 3 ; Q2 is the amount of foam floating particles with a particle size of d2, m 3 , d2>d1; H is the design support joint height, m; L is the designed support joint length, m; W is the designed support joint width, m; α is the percentage of the volume of foam floating particles filling the crack to the total volume of the crack, 10%~30%; η is the degree of closed cracks, %; n is the number of fracturing stages, dimensionless; γ is the loss rate of foam floating particles, %; Select the construction pumping procedure according to the reservoir type.

2. The method for controlling fracture height by utilizing foam floating particles to transform thin oil and gas reservoirs according to claim 1, characterized in that: The selection rule of the foam floating particle size is: If the ratio of the minimum horizontal principal stress of the interlayer to the reservoir is 0.68-1.22, the ratio of the friction coefficient of the interlayer to the reservoir is 0.29-1.43, and the ratio of the tensile strength of the interlayer to the reservoir is 0.17-5.1, low-viscosity fracturing fluid and medium-viscosity fracturing fluid are used for fracturing construction; for low-viscosity fracturing fluid, foam floating particles with a particle size d1 of 420μm-212μm are selected; for medium-viscosity fracturing fluid, foam floating particles with a particle size d2 of 590μm-297μm are selected; If the ratio of the minimum horizontal principal stress of the interlayer to the reservoir is 1.22~1.46, the ratio of the friction coefficient of the interlayer to the reservoir is 1.43~1.85, and the ratio of the tensile strength of the interlayer to the reservoir is 5.1~11.3, fracturing construction is carried out with medium-viscosity fracturing fluid and high-viscosity fracturing fluid; for medium-viscosity fracturing fluid, foam floating particles with a particle size d1 of 178μm~150μm are selected; for high-viscosity fracturing fluid, foam floating particles with a particle size d2 of 420μm~212μm are selected.

3. The method for controlling fracture height by utilizing foam floating particles for thin oil and gas reservoir reconstruction according to claim 2, characterized in that: The selection rules of the foam floating particle types are: For low-viscosity fracturing fluid, polyamide foam floating particles are selected as foam floating particles, and their density is 0.16g / cm 3 ~0.51g / cm 3 For medium viscosity fracturing fluid, the foam floating particles are selected as silica gel foam floating particles, with a density of 0.33g / cm 3 ~0.74g / cm 3 For high-viscosity fracturing fluid, the foam floating particles are selected from polytetrafluoroethylene foam floating particles, whose density is 0.57g / cm 3 ~0.95g / cm 3 .

4. The method for controlling fracture height by utilizing foam floating particles to transform thin oil and gas reservoirs according to claim 3, characterized in that: (1) The internal foam particles of polyamide foam floating particles are polyamide foam particles with a density of 0.05g / cm 3 ~0.25g / cm 3 , particle size is 120μm-560μm, operating temperature range is 40℃~150℃, compressive strength is 1MPa~2MPa; (2) The internal foam particles of the silica gel foam floating particles are silica gel foam particles with a density of 0.12g / cm 3 ~0.45g / cm 3 , particle size is 120μm-560μm, operating temperature range is 50℃~250℃, compressive strength is 1MPa~2MPa; (3) The internal foam particles of the polytetrafluoroethylene foam floating particles are polytetrafluoroethylene foam particles with a density of 0.3g / cm 3 ~0.65g / cm 3 , particle size is 120μm-560μm, operating temperature range is 200℃~260℃, and compressive strength is 2MPa~4MPa.

5. The method for controlling fracture height by utilizing foam floating particles for thin oil and gas reservoir reconstruction according to claim 1, characterized in that: The external coating is phenolic epoxy resin, and its density is 1.18g / cm 3 ~1.25g / cm 3 The operating temperature range is 10℃~180℃, and the compressive strength is 100MPa~250MPa.

6. The method for controlling fracture height by utilizing foam floating particles for thin oil and gas reservoir reconstruction according to claim 1, characterized in that: The preparation method of the foam floating particles is: The internal foam particles are completely immersed in the liquid external coating and mixed evenly, and individual internal foam particles are taken out and separated, and the individual internal foam particles are evenly wrapped by the external coating; then, they are heated and cured and allowed to stand to finally obtain foam floating particles.

7. The method for controlling fracture height by utilizing foam floating particles to transform thin oil and gas reservoirs according to claim 3, characterized in that: If the reservoir is a tight sandstone reservoir and the sand-carrying fluid is non-viscous fracturing, the construction pumping procedure is as follows: (1-1) Add 20% Q1~100% Q1 of foam floating particles with a particle size of d1 to the pre-liquid with a viscosity of ν1, and 3 / min~8m 3 / min into the wellbore; (1-2) Add 50% Q1~80% Q1 of foam floating particles with a particle size of d1 to the sand-carrying fluid with a viscosity of ν1, and 3 / min~10m 3 / min into the wellbore; or add Q2 foam floating particles with a particle size of d2 to the sand-carrying fluid with a viscosity of ν2, with a displacement of 2m 3 / min~15m 3 / min into the wellbore; (1-3) With a displacement of 1m 3 / min~12m 3 The displacement fluid is injected at a rate of / min to complete the controlled fracture high pressure fracturing construction.

8. The method for controlling fracture height by using foam floating particles to transform thin oil and gas reservoirs according to claim 7, characterized in that: If the reservoir is a tight sandstone reservoir and the sand-carrying fluid is used for viscous fracturing, the specific construction pumping procedure is as follows: (2-1) Add 20% Q1~100% Q1 of foam floating particles with a particle size of d1 to the pre-liquid with a viscosity of ν1, and 3 / min~8m 3 / min into the wellbore; (2-1) Add 50% Q1~80% Q1 of foam floating particles with a particle size of d1 to the sand-carrying fluid with a viscosity of ν1, and 3 / min~10m 3 / min into the wellbore; (2-3) Add Q2 foam floating particles with a particle size of d2 to the sand-carrying fluid with a viscosity of ν2, with a displacement of 2m 3 / min~15m 3 / min into the wellbore; (2-4) With a displacement of 1m 3 / min~12m 3 Inject displacement fluid at a rate of / min to complete the controlled fracture high-pressure fracturing operation; Among them, viscosity ν1≤viscosity ν2.

9. The method for controlling fracture height by utilizing foam floating particles to transform thin oil and gas reservoirs according to claim 3, characterized in that: If the reservoir is a carbonate reservoir, the specific construction pumping procedure is as follows: (3-1) Add 20%Q1~40%Q1 foam floating particles with a particle size of d1 to the pre-acid, with a displacement of 1m 3 / min~5m 3 / min into the wellbore; (3-2) Add 40% Q1~70% Q1 of foam floating particles with a particle size of d1 to the pre-liquid with a viscosity of ν1, and 3 / min~8m 3 / min into the wellbore; (3-3) Add Q2 foam floating particles with a particle size of d2 to the sand-carrying fluid with a viscosity of ν2, with a displacement of 2m 3 / min~12m 3 / min into the wellbore; (3-4) With a displacement of 1m 3 / min~10m 3 The displacement fluid is injected at a rate of / min to complete the controlled fracture high pressure fracturing construction.

10. The method for controlling fracture height by utilizing foam floating particles to transform thin oil and gas reservoirs according to claim 3, characterized in that: If the reservoir is a coal rock reservoir, the specific construction pumping procedure is as follows: (4-1) Add 20% Q1~50% Q1 of foam floating particles with a particle size of d1 to the pre-liquid with a viscosity of ν1, and 3 / min~6m 3 / min into the wellbore; (4-2) Add 10% Q1~20% Q1 of foam floating particles with a particle size of d1 to the sand-carrying fluid with a viscosity of ν2, and 3 / min~15m 3 / min into the wellbore; (4-3) Add 20% Q2~40% Q2 of foam floating particles with a particle size of d2 to the sand-carrying fluid with a viscosity of ν2, and 3 / min~10m 3 / min into the wellbore; (4-4) Repeat steps (4-2) and (4-3) 3 to 5 times; (4-5) With a displacement of 1m 3 / min~8m 3 The displacement fluid is injected at a rate of / min to complete the controlled fracture high pressure fracturing construction.