A method for recovering super-heavy oil

Abstract

The application provides a super-thick oil recovery method, which comprises the following steps: collecting basic information of a research block, judging a fracture type; calculating a reservoir fracture pressure, forming steam injection parameter limits; establishing a numerical simulation model, calculating an injection fluid swept range, correcting porosity and permeability in the swept range; correcting a relative permeability curve in a steam swept area, optimizing design of a vertical well, a horizontal well parameter and a well arrangement mode; optimizing calculation of super-fracture pressure huff and puff parameters; optimizing calculation of a steam assisted gravity drainage technology opportunity and steam assisted gravity drainage technology injection-production parameters; performing super-fracture pressure huff and puff to steam assisted gravity drainage technology development effect prediction, and determining a recovery ratio of the research block. The recovery ratio of the super-thick oil reservoir is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of oilfield development technology, and in particular to a method for recovering extra-heavy oil. Background Technology

[0002] Heavy oil resources are abundant, accounting for over 70% of the world's total oil reserves, and have enormous development potential. Steam-assisted gravity drainage (SAD) technology for vertical and horizontal wells is an important heavy oil extraction technology: vertical wells are arranged on both sides of a horizontal well, with the perforations in the vertical well slightly higher than those in the horizontal well. Steam is injected into the vertical well, while production occurs in the horizontal well. By establishing thermal connectivity between the vertical and horizontal wells, a drainage channel is formed, allowing crude oil to be extracted from the horizontal well. In the initial development stage, the reservoir needs to be preheated, and a steam chamber needs to be constructed to establish thermal connectivity; this stage is crucial for the success of SAD technology.

[0003] Steam injection preheating can reduce reservoir pressure, improve steam efficiency, provide a certain production capacity, and reduce preheating costs, making it the main preheating method in the development of steam-assisted drainage technology. Extra-heavy oil reservoirs have high crude oil viscosity (>50000 mPa·s), making viscosity reduction difficult. Conventional steam injection provides limited heat, and the steam wave radius is small, making it impossible to achieve overall reservoir preheating in a short time. This makes the formation of drainage channels difficult, and the development process faces two main problems: First, the steam heating range is limited; the conventional steam injection heating radius is only about 20 meters. Due to viscosity, the drainage radius is further reduced, making efficient development impossible with conventional steam injection. Second, the effective period is short; due to limited steam injection volume and high heat loss, the development cycle of conventional injection is only 2 to 3 months. Frequent turnover increases operating costs and heat loss during operation. Therefore, it is necessary to improve the preheating method, expand the preheating radius, improve the preheating effect, shorten the preheating time, reduce the input-output ratio, and improve the development effect. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide a method for recovering extra-heavy oil that overcomes or at least partially solves the above problems.

[0005] According to one aspect of the present invention, a method for recovering extra-heavy oil is provided, the method comprising:

[0006] Step S1: Collect basic data on the research block and determine the type of crack;

[0007] Step S2: Calculate the reservoir fracture pressure and establish steam injection parameter limits;

[0008] Step S3: Establish a numerical simulation model, calculate the swept range of the injected fluid, and correct the porosity and permeability within the swept range;

[0009] Step S4: Correct the relative permeability curve within the vapor-saturated area and optimize the design parameters and well placement of vertical and horizontal wells;

[0010] Step S5: Optimize the calculation of over-rupture pressure throughput parameters;

[0011] Step S6: Optimize the timing of switching to steam-assisted gravity drainage technology and the injection and production parameters of steam-assisted gravity drainage technology;

[0012] Step S7: Predict the development effect of the super-fracture pressure huff and puff to steam-assisted gravity drainage technology and determine the recovery rate of the study block.

[0013] Optionally, step S1: collecting basic data on the research block and determining the crack type specifically includes:

[0014] The basic data collected for the research blocks include the burial depth, sand thickness, effective thickness, reservoir physical parameters, rock physical properties, fluid properties, temperature, pressure, oil saturation, relative permeability, viscosity-temperature relationship, reservoir type, and development dynamic parameters of the research blocks.

[0015] By comparing triaxial stresses, the type of crack can be determined by:

[0016] When the vertical stress is less than the horizontal stress, a horizontal crack forms.

[0017] σ H >σ Z (1)

[0018] Where, σ H For horizontal stress; σ Z Stress is in the vertical direction;

[0019] When the vertical stress is greater than the horizontal stress, a vertical crack is formed:

[0020] σ H <σ Z (2).

[0021] Optionally, in step S2, the parameters for calculating the minimum steam injection temperature, minimum steam injection rate, minimum steam injection dryness, and minimum steam injection quantity during the super-fracture pressure steam injection process are used to ensure that the steam injection pressure is slightly higher than the rock fracture pressure.

[0022] The fracture pressure of the reservoir rock is calculated using the formula for calculating reservoir fracture pressure.

[0023] P rb =0.0223Hα+(1.03-α)P i (3)

[0024] Among them, P rb For the rupture pressure gradient; Pi α represents the pressure gradient of the overlying strata; H represents the medium depth of the reservoir; α is a constant used to calculate the fracture pressure, typically 0.38–0.50.

[0025] Using the energy conservation method, the steam injection pressure is calculated as follows:

[0026]

[0027]

[0028]

[0029]

[0030] Among them, P inj For steam injection pressure difference; i s For mass steam injection rate; ν lm Specific volume of saturated steam; J o For production well oil production index; I s Formation vapor absorption factor; B o μ is the crude oil volume coefficient. o Where is the viscosity of the crude oil in the formation; h is the thickness of the oil layer; K is the rock permeability; K ro R is the relative permeability of the oil phase; A is the effective area of ​​the well pattern; r w Where S is the oil well radius; S is the skin factor; E hs For oil reservoir thermal efficiency; Formation pressure; P s This refers to the steam injection pressure at the bottom of the well.

[0031] Optionally, step S3: establishing a numerical simulation model, calculating the swept range of the injected fluid, and correcting the porosity and permeability within the swept range specifically includes:

[0032] The collected data is used for numerical modeling in numerical simulation software;

[0033] Calculate the vapor sweep radius, correct for porosity and permeability within the sweep radius, and simulate the effect of reservoir plastic deformation;

[0034] By modifying the Marx-Langenheim model, the volume and radius of the injected steam wave were calculated, simulating the effect of super-rupture pressure steam injection on the wave radius.

[0035] The equation for calculating the heating volume of a vertical well is as follows:

[0036]

[0037] Among them, V v For vertical well intake and exhaust heating volume; i s H represents the rate of steam injection.m t is the enthalpy of water vapor; t is the steam injection time; M is the enthalpy of water vapor. R T represents the heat capacity of the reservoir. h T represents the average temperature of the vapor-saturated area. i E represents reservoir temperature. hs For heating efficiency.

[0038] The equation for calculating the heating radius of a vertical well is:

[0039]

[0040] Where, r V ξ is the vertical well injection heating radius; h is the fracture steam injection correction factor; t The thickness is the reservoir layer.

[0041] The equation for calculating the heating volume of a horizontal well is as follows:

[0042]

[0043] in, V is the volume of water pumped into and out of the horizontal well for heating. hU This refers to the heating volume without considering heat loss from the top and bottom cap layers.

[0044]

[0045] The equation for calculating the heating radius of a horizontal well is:

[0046]

[0047] Where, r h The heating radius for horizontal well throughput.

[0048] Optionally, step S4: correcting the relative permeability curve within the vapor-sweeped area and optimizing the design parameters and well placement of vertical and horizontal wells specifically includes:

[0049] The relative permeability curves within the vapor-sweeped area are corrected, including the relative permeability of the water phase, oil phase, and gas phase.

[0050]

[0051] Among them, S ew S represents the saturation level of movable water. w S represents the water phase saturation. wc S represents the bound water saturation. orw Residual oil saturation;

[0052]

[0053] Among them, S elS represents the saturation level of the movable fluid. o S represents oil phase saturation. lc S represents the residual saturation of the liquid phase. gc This represents the residual saturation of the gas phase.

[0054] k rw =k rw (S ew (15)

[0055] Where, k rw The relative permeability of the aqueous phase;

[0056] k rg =k rg (S el (16)

[0057] Where, k rg This refers to the relative permeability of the gas phase.

[0058]

[0059] Where, k ro The relative permeability of the oil phase; k rocw k represents the relative permeability of the oil phase under bound water conditions. row k represents the relative permeability of the oil phase at a certain water saturation level. rog The relative permeability of the oil phase at a certain gas saturation level.

[0060] Optionally, step S5: optimizing the calculation of the super-rupture pressure throughput parameters specifically includes:

[0061] Numerical simulation methods were used to optimize the calculation of parameters such as steam injection temperature, steam injection rate, steam injection dryness, steam injection volume, well shut-in time, and fluid production rate during the over-rupture pressure injection process.

[0062] Optionally, step S6: optimizing the timing of the steam-assisted gravity drainage technology and the injection and production parameters of the steam-assisted gravity drainage technology specifically includes: using numerical simulation methods to optimize the calculation of the parameters of the steam-assisted drainage technology, mainly including the timing of the steam-assisted drainage technology, steam injection rate, steam injection temperature, steam injection dryness, and production rate.

[0063] Optionally, step S7: predicting the development effect of super-fracture pressure huff and puff to steam-assisted gravity drainage technology and determining the recovery rate of the study block specifically includes: using numerical simulation methods to calculate the temperature distribution, pressure distribution and saturation distribution after the development of super-fracture pressure huff and puff to steam-assisted drainage technology, and determining the cumulative oil production and recovery rate of the study block.

[0064] This invention provides a method for recovering extra-heavy oil. The method includes: collecting basic data of the study block and determining the fracture type; calculating the reservoir fracture pressure and establishing steam injection parameter limits; establishing a numerical simulation model, calculating the swept range of the injected fluid, and correcting the porosity and permeability within the swept range; correcting the relative permeability curve within the steam swept area, and optimizing the design parameters and well layout of vertical and horizontal wells; optimizing the calculation of super-fracture pressure huff and puff parameters; optimizing the calculation of the timing of steam-assisted gravity drainage technology and the injection and production parameters of steam-assisted gravity drainage technology; predicting the development effect of super-fracture pressure huff and puff to steam-assisted gravity drainage technology, and determining the recovery rate of the study block. This method effectively improves the recovery rate of extra-heavy oil reservoirs.

[0065] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0066] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0067] Figure 1 This is a flow chart of the process for enhancing the recovery rate of extra-heavy oil according to the present invention;

[0068] Figure 2 The horizontal crack in Specific Embodiment 1 of the present invention;

[0069] Figure 3 The vertical crack in specific embodiment 2 of the present invention;

[0070] Figure 4 The following are bar charts and line graphs comparing the recovery rates of different steam injection dryness in specific embodiment 1 of the present invention;

[0071] Figure 5 This is a schematic diagram of a 3-vertical-2-well network in a specific embodiment 1 of the present invention;

[0072] Figure 6 This is a schematic diagram of a 6-vertical-1 water well network in a specific embodiment 2 of the present invention. Detailed Implementation

[0073] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0074] The terms "comprising" and "having," and any variations thereof, in the specification, embodiments, claims, and drawings of this invention are intended to cover non-exclusive inclusion, such as including a series of steps or units.

[0075] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0076] like Figure 1 As shown, a method for recovering extra-heavy oil includes:

[0077] Step S1: Collect basic data on the research block and determine the type of crack;

[0078] Step S2: Calculate the reservoir fracture pressure and establish steam injection parameter limits;

[0079] Step S3: Establish a numerical simulation model, calculate the swept range of the injected fluid, and correct the porosity and permeability within the swept range;

[0080] Step S4: Correct the relative permeability curve within the vapor-saturated area and optimize the design parameters and well placement of vertical and horizontal wells;

[0081] Step S5: Optimize the calculation of over-rupture pressure throughput parameters;

[0082] Step S6: Optimize the timing of switching to steam-assisted gravity drainage technology and the injection and production parameters of steam-assisted gravity drainage technology;

[0083] Step S7: Predict the development effect of the super-fracture pressure huff and puff to steam-assisted gravity drainage technology and determine the recovery rate of the study block.

[0084] Example 1

[0085] This invention takes a block in Oilfield A as an example to conduct simulation and prediction of the development of super-fracture pressure huff and puff to steam-assisted drainage technology, including the following steps:

[0086] Step 1: Collect basic data on the research block, including an area of ​​16.3 km². 2 Controlled reserves of 3762.3·10 4The reservoir has a burial depth of 450–610 m, an effective thickness of 5–10 m, a porosity of 20.2%–27%, and a permeability of 152–863 mD. It is dominated by thick conglomerate and sandstone conglomerate layers, which are stable and continuous. The overall structure is a monocline with a northwest-southeast gradient, dissected by internal secondary faults, forming multiple fault blocks. The strata dip angle is 8°–10°, the median grain size is 0.11–0.38 mm, the average is 0.28 mm, the sorting coefficient is 1.31–1.82, the average is 1.48, the crude oil viscosity at 80℃ is 7801–32561 mPa·s, and the crude oil density at 20℃ is 0.9732–0.9876 t / m³. 3 The vertical stress σ Z =0.015MPam is less than the horizontal stress σ H =0.022 MPa, therefore the target reservoir will form horizontal fractures, such as Figure 2 As shown;

[0087] Step 2: The fracture pressure constant α is selected as 0.45. The fracture pressure of the study block is calculated to be 9.385 MPa. Based on the bottom hole pressure calculation, the steam injection rate needs to be above 163.7 t / d to achieve reservoir rock fracture.

[0088] Step 3: The effective reservoir thickness is set at 8m, the steam injection rate is 8000 kg / h, the enthalpy of injected steam is 429 kcal / kg, and the reservoir heat capacity is 544 kcal / (m³). 3 With an initial formation temperature of 30℃ and a fracture steam injection correction factor of 1.23, the calculated steam injection heating radius for vertical wells is 28.15m and for horizontal wells is 24.93m. A numerical reservoir was established using numerical simulation software, and the reservoir porosity and permeability within the injected fluid-affected area were corrected to obtain a simulated reservoir considering reservoir plastic deformation.

[0089] Step 4: Utilize numerical simulation methods, such as... Figure 5 As shown, the well network consists of 3 vertical wells and 2 horizontal wells, with the vertical wells located in the middle of the horizontal wells. The optimized design has a horizontal well length of 200 meters, and the vertical wells are located at 1 / 4, 1 / 2 and 3 / 4 of the length of the horizontal wells, respectively. The horizontal distance between the vertical wells and the horizontal wells is 35 meters, and the vertical height difference is 3 meters.

[0090] Step 5: Optimize the calculation of over-fracture pressure injection parameters using numerical simulation. Five wells adopt integrated injection, with a steam injection ratio of 2:1 between horizontal and vertical wells. The cycle steam injection volume for horizontal wells is 3000t, and for vertical wells it is 1500t. The steam injection rate for horizontal wells is 300t / d, and for vertical wells it is 150t / d. The bottom hole steam dryness should be above 0.7. The expected oil production for the first cycle of steam injection is 2176t, with an oil-steam ratio of 0.39 and a recovery rate of 2.27%.

[0091] Step 6: Optimize the parameters of the steam-assisted oil draining technology, such as... Figure 4 As shown, the timing of switching to steam-assisted oil drainage technology is three cycles. Effective thermal communication is achieved between vertical and horizontal wells. During the steam-assisted oil drainage technology stage, the steam injection dryness is maintained above 0.7. The initial stage is the process of forming a steam chamber in the injection well, with a small production-injection ratio (<1). The transition stage is the process of establishing pressure balance between injection and production wells, with a large production-injection ratio (>1.4). The stable stage is characterized by stable development, with a daily steam injection rate of 57.6 t / d (28.8 t / d per well), a daily liquid production of approximately 74.9 t / d (37.4 t / d per well), and a production-injection ratio of approximately 1.3.

[0092] Step 7: Predict the development effect of super-fracture pressure huff and puff to steam-assisted drainage technology in the study block. Three cycles of super-fracture pressure huff and puff resulted in a recovery rate of 6.36%. Five years of steam-assisted drainage technology development resulted in a recovery rate of 14.5%. The final recovery rate of the study block was 20.84%, with a cumulative oil-steam ratio of 0.19.

[0093] Example 2

[0094] This invention takes a block in Oilfield B as an example to conduct simulation and prediction of the development of super-fracture pressure huff and puff to steam-assisted drainage technology, including the following steps:

[0095] Step 1: Collect basic data on the research block, including an area of ​​13.1 km². 2 Controlled reserves of 2762.3·10 4 The reservoir has a burial depth of 890–900 m, an effective thickness of 8–12 m, a porosity of 19.8%–24%, and a permeability of 1032–2561 mD. It is stable, well-continuous, and generally exhibits a monocline structure with a southwest-high and northeast-low gradient. The strata dip angle is 2°–3°, the median grain size is 0.13–0.28 mm, the average is 0.21 mm, the sorting coefficient is 1.34–1.77, the average is 1.44, and the crude oil viscosity at 80℃ is 6841–26588 mPa·s, with a vertical stress σ... Z =0.027 MPaam is less than the horizontal stress σ H =0.023 MPa, the target reservoir will form vertical fractures, such as Figure 3 As shown;

[0096] Step 2: The fracture pressure constant α is selected as 0.45. The fracture pressure of the study block is calculated to be 13.05 MPa. Based on the bottom hole pressure calculation, the steam injection rate needs to be above 358.8 t / d to achieve reservoir rock fracture.

[0097] Step 3: The effective reservoir thickness is set at 10m, the steam injection rate is 16000 kg / h, the enthalpy of injected steam is 429 kcal / kg, and the reservoir heat capacity is 578 kcal / (m³). 3With an initial formation temperature of 56℃ and a fracture steam injection correction factor of 1.15, the calculated steam injection heating radius for vertical wells is 38.56m and for horizontal wells is 31.77m. A numerical reservoir was established using numerical simulation software, and the reservoir porosity and permeability within the injected fluid-affected area were corrected to obtain a simulated reservoir considering reservoir plastic deformation.

[0098] Step 4: Utilize numerical simulation methods, such as... Figure 6 As shown, there is a well network of 6 vertical wells and 1 horizontal well, with the vertical wells located on both sides of the horizontal well. The horizontal well is 300 meters long in the optimized design. The vertical wells are located at the heel, toe, and middle of the horizontal well, with a horizontal distance of 45 meters from the horizontal well and a vertical height difference of 3 meters.

[0099] Step 5: Optimize the calculation of over-fracture pressure injection parameters using numerical simulation. Seven wells adopt overall injection, with a steam injection ratio of 3:1 between horizontal and vertical wells. The cycle steam injection volume for horizontal wells is 6000t, and for vertical wells it is 2000t. The steam injection rate for horizontal wells is 800t / d, and for vertical wells it is 400t / d. The bottom hole steam dryness should be above 0.7. The expected oil production for the first cycle of steam injection is 8136t, with an oil-steam ratio of 0.45 and a recovery rate of 2.33%.

[0100] Step 6: Optimize the parameters of the steam-assisted drainage technology. The timing for switching to steam-assisted drainage technology is 5 cycles. Effective thermal connection is achieved between vertical and horizontal wells. During the steam-assisted drainage technology stage, the steam injection dryness is maintained above 0.8. In the initial stage, the steam injection well is in the process of forming a steam chamber, and the production-injection ratio is small (<1). In the transition stage, the pressure balance is established between the injection and production wells, and the production-injection ratio is large (>1.4). In the stable stage, the development is stable, with a daily steam injection rate of 216t / d (36t / d per well), a daily liquid production of approximately 241.9t / d (241.9t / d per well), and a production-injection ratio of approximately 1.12.

[0101] Step 7: Predict the development effect of super-fracture pressure huff and puff to steam-assisted drainage technology in the study block. Five cycles of super-fracture pressure huff and puff resulted in an recovery rate of 8.21%. Five years of steam-assisted drainage technology development resulted in an recovery rate of 17.12%. The final recovery rate of the study block was 25.33%, with a cumulative oil-steam ratio of 0.16.

[0102] Beneficial effects: By rationally arranging the well network, well locations, and parameters of vertical and horizontal wells, and optimizing the calculation of huff and puff parameters during the super-fracture pressure huff and puff process and injection and production parameters during the steam-assisted drainage technology process, the recovery rate of the study block can be calculated. This invention can effectively improve the recovery rate of extra-heavy oil reservoirs. The development of steam-assisted drainage technology after super-fracture pressure huff and puff forms a process method for improving the recovery rate of extra-heavy oil.

[0103] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for harvesting extra-heavy oil, characterized in that, The harvesting method includes: Step S1: Collect basic data on the research block and determine the type of crack; Step S2: Calculate the reservoir fracture pressure and establish steam injection parameter limits; Step S2 further includes: calculating the parameters of minimum steam injection temperature, minimum steam injection rate, minimum steam injection dryness and minimum steam injection quantity during the super-fracture pressure steam injection process, in order to ensure that the steam injection pressure is slightly higher than the rock fracture pressure. The fracture pressure of the reservoir rock is calculated using the formula for calculating reservoir fracture pressure. （3） in, The rupture pressure gradient; The pressure gradient of the overlying strata; It is a medium-deep reservoir; This is a constant used to calculate the burst pressure, typically ranging from 0.38 to 0.

50. Using the energy conservation method, the bottom hole steam injection pressure is calculated as follows: （4） （5） （6） （7） in, This refers to the steam injection pressure difference; For mass steam injection rate; Specific volume of saturated steam; For production well oil production index; It is the formation vapor absorption factor; This is the crude oil volume coefficient; This refers to the viscosity of the formation crude oil. Oil layer thickness; Rock permeability; The relative permeability of the oil phase; The effective area of ​​the well network; The radius of the oil well; It is an epidermal factor; For oil reservoir thermal efficiency; Formation pressure; This refers to the steam injection pressure at the bottom of the well. Step S3: Establish a numerical simulation model, calculate the swept range of the injected fluid, and correct the porosity and permeability of the swept range of the injected fluid; The collected data is used for numerical modeling in numerical simulation software; Calculate the vapor sweep radius, correct for porosity and permeability within the sweep radius, and simulate the effect of reservoir plastic deformation; By modifying the Marx-Langenheim model, the swept volume and radius of the injected fluid were calculated, and the effect of super-rupture pressure steam injection on the swept radius was simulated. The equation for calculating the heating volume of a vertical well is: (8) in, For vertical well intake and exhaust heating volume; For mass steam injection rate; t represents the enthalpy of water vapor; t represents the steam injection time. The heat capacity of the reservoir; The average temperature of the vapor-saturated region; For reservoir temperature; For oil reservoir thermal efficiency; The equation for calculating the heating radius of a vertical well is: (9) in, The heating radius for vertical well intake and exhaust; This is the steam injection correction factor for rupture. The thickness of the reservoir; The equation for calculating the heating volume of a horizontal well is as follows: (10) in, For horizontal well intake and exhaust heating volume; This refers to the heating volume without considering heat loss from the top and bottom cap layers. (11) The equation for calculating the heating radius of a horizontal well is: (12) in, The horizontal well's intake and exhaust heating radius; Step S4: Correct the relative permeability curve within the range of the injected fluid, and optimize the design parameters and well placement of vertical and horizontal wells; The relative permeability curves within the range of the injected fluid are corrected, including the relative permeability of the water phase, the relative permeability of the oil phase, and the relative permeability of the gas phase. (13) in, The saturation level of movable water; This refers to the water phase saturation. To bind water saturation; Residual oil saturation; (14) in, The saturation level of the movable fluid; Oil phase saturation; This refers to the residual saturation of the liquid phase. This refers to the residual saturation of the gas phase. (15) in, The relative permeability of the aqueous phase; (16) in, This refers to the relative permeability of the gas phase. (17) in, This refers to the relative permeability of the oil phase. The relative permeability of the oil phase under bound water conditions; The relative permeability of the oil phase at a certain water saturation level; The relative permeability of the oil phase at a certain gas saturation level; Step S5: Optimize the calculation of over-rupture pressure throughput parameters; Step S6: Optimize the timing of switching to steam-assisted gravity drainage technology and the injection and production parameters of steam-assisted gravity drainage technology; Step S7: Predict the development effect of the super-fracture pressure huff and puff to steam-assisted gravity drainage technology and determine the recovery rate of the study block.

2. The method for recovering extra-heavy oil according to claim 1, characterized in that, Step S1: Collecting basic data of the research block and determining the crack type specifically includes: The basic data collected for the research blocks include the burial depth, sand thickness, effective thickness, reservoir physical parameters, rock physical properties, fluid properties, temperature, pressure, oil saturation, relative permeability, viscosity-temperature relationship, reservoir type, and development dynamic parameters of the research blocks. By comparing triaxial stresses, the type of crack can be determined by: When the vertical stress is less than the horizontal stress, a horizontal crack forms. （1） in, The stress is in the horizontal direction; Stress is in the vertical direction; When the vertical stress is greater than the horizontal stress, a vertical crack is formed: （2）。 3. The method for recovering extra-heavy oil according to claim 1, characterized in that, Step S5: Optimizing the calculation of the super-rupture pressure surge parameters specifically includes: Numerical simulation methods were used to optimize the calculation of parameters such as steam injection temperature, steam injection rate, steam injection dryness, steam injection volume, well shut-in time, and fluid production rate during the over-rupture pressure injection process.

4. The method for recovering extra-heavy oil according to claim 1, characterized in that, Step S6: Optimizing the timing of the steam-assisted gravity drainage technology and the injection and production parameters of the steam-assisted gravity drainage technology specifically includes: using numerical simulation methods to optimize the calculation of the parameters of the steam-assisted gravity drainage technology, mainly including the timing of the steam-assisted gravity drainage technology, steam injection rate, steam injection temperature, steam injection dryness, and liquid production rate.

5. The method for recovering extra-heavy oil according to claim 1, characterized in that, Step S7: Predicting the development effect of the super-fracture pressure huff and puff to steam-assisted gravity drainage technology and determining the recovery rate of the study block specifically includes: using numerical simulation methods to calculate the temperature distribution, pressure distribution and saturation distribution after the development of the super-fracture pressure huff and puff to steam-assisted gravity drainage technology, and determining the cumulative oil production and recovery rate of the study block.

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