Processing method and device for non-condensate gas assisted SAGD numerical simulation

Abstract

The invention discloses a processing method and device for non-condensate gas assisted SAGD numerical simulation. The method comprises the following steps: acquiring a corresponding diffusion coefficient of non-condensate gas in a gas phase through an experimental test; respectively establishing non-condensate gas phase state model reaction equations corresponding to non-instantaneous dissolution and non-instantaneous degassing; respectively setting corresponding gas-liquid phase permeability of steam and non-condensate gas, and respectively and correspondingly carrying out interpolation calculation according to gas phase composition; according to the obtained diffusion coefficient, the obtained non-condensate gas phase state model reaction formula and the obtained gas-liquid phase permeability, numerical simulation calculation of non-condensate gas assisted SAGD production is carried out. By defining the diffusion coefficient of the non-condensate gas in the gas phase, introducing a phase state model reaction formula of non-instantaneous dissolution and non-instantaneous degassing, and setting different gas-liquid phase permeability for the steam and the non-condensate gas, the numerical simulation result is greatly improved, the oil production is not obviously reduced while the steam amount is greatly reduced by mixed injection of the non-condensate gas, and the method is suitable for large-scale production. And a reference can be better provided for guiding development of optimization design.

Description

Technical Field

[0001] The present invention relates to the technical field of heavy oil or oil sand development, and in particular to a processing method and device for non-condensate gas assisted SAGD numerical simulation. Background Art

[0002] SAGD (Steam-Assisted Gravity Drainage) has achieved tremendous success in developing ultra-heavy oil and oil sands projects. However, the gasoline ratio tends to increase annually in the mid- to late-stage, reducing economic benefits. Therefore, in field practice over the past decade or so, non-condensable gases such as natural gas, CO2, nitrogen, or flue gas have often been mixed with the injected steam (referred to as non-condensable gas-assisted SAGD technology) to reduce steam consumption and gasoline ratio.

[0003] However, when using non-condensable gas to assist SAGD numerical simulation in the existing technology, there are significant differences between the numerical simulation results and experimental tests or field monitoring, mainly manifested in the following aspects: 1) In the numerical simulation, non-condensable gas often accumulates on the lateral boundary of the steam chamber, thereby hindering the lateral expansion of the steam chamber, while the experimental temperature field or field temperature observation wells show that non-condensable gas tends to accumulate at the top of the steam chamber, thereby playing a better role in insulation; 2) In the numerical simulation, the injection of non-condensable gas significantly reduces the steam volume and also significantly reduces the oil production, while on-site observation only observes a significant reduction in steam volume, and the oil production is not significantly affected.

[0004] Some early numerical simulations artificially reduced the initial dissolved gas content (SPE 150539) to mitigate its adverse effects on SAGD production. Existing numerical simulations also attempt to increase gas production by increasing the solubility of non-condensable gases in the aqueous phase (SPE 113234; SPE 148943; SPE 157773), or by reducing the critical gas saturation in the gas phase (SPE 157837), in an attempt to mitigate their adverse effects on oil production, but with limited success. Other numerical simulation methods have proposed incorporating aquathermolysis to approximate gas production (SPE 157837), which only improves gas production to a certain extent but fails to reduce the obstruction of non-condensable gases in the steam chamber and their adverse effects on oil production.

[0005] In summary, most existing numerical simulation methods have the problem that non-condensable gas accumulates at the boundary of the steam chamber rather than at the top, thereby hindering the expansion of the steam chamber and affecting the development optimization design effect. Summary of the Invention

[0006] In view of the above problems, the present invention is proposed to provide a method and apparatus for non-condensable gas assisted SAGD numerical simulation that overcomes the above problems or at least partially solves the above problems.

[0007] Other features and advantages of the present invention will become apparent from the following detailed description, or may be learned in part by practice of the present invention.

[0008] According to a first aspect of an embodiment of the present invention, a method for processing non-condensable gas-assisted SAGD numerical simulation is provided. The method for processing non-condensable gas-assisted SAGD numerical simulation includes:

[0009] S1. Steady-state method based on Stephen diffuser: Through experimental testing, non-condensable gas is mixed into saturated steam at SAGD operating pressure to obtain the diffusion coefficient of non-condensable gas in the gas phase;

[0010] S2. Establish the non-condensable gas phase model reaction equations corresponding to non-instantaneous dissolution and non-instantaneous degassing respectively;

[0011] S3. Set the gas-liquid permeability corresponding to steam and non-condensable gas respectively, and perform interpolation calculations based on the gas phase composition. The gas-liquid permeability corresponding to steam or non-condensable gas is obtained through steady-state or unsteady-state testing. The gas-liquid permeability of mixed steam and non-condensable gas is interpolated using a linear or exponential formula.

[0012] S4. Numerical simulation calculations for non-condensable gas assisted SAGD production are performed based on the obtained diffusion coefficient, non-condensable gas phase model reaction equation, steam, and corresponding gas-liquid permeability of non-condensable gas.

[0013] In some embodiments of the present invention, in step S2, establishing a non-instantaneous dissolved non-condensable gas phase model reaction equation includes:

[0014] In the dissolution process of non-condensable gas into bubbles, it is defined as Also define the dissolution rate Where A1 is the first reaction frequency factor, E a1 is the first activation energy, RT is room temperature, the first reaction frequency factor A1 is 1.64E+7, the first activation energy E a1 It is 4736.5J / mole.

[0015] In some embodiments of the present invention, in step S2, establishing a non-instantaneous degassing non-condensable gas phase model reaction equation includes:

[0016] In the degassing process of non-condensable gas, bubbles coalesce into free gas as the temperature and pressure change, which is defined as Also define the dissolution rate Where A2 is the second reaction frequency factor, E a2 is the second activation energy, RT is room temperature, the second reaction frequency factor A2 is 1.0E-3 to 5.0E-3, and the second activation energy E a2 is 0.

[0017] In some embodiments of the present invention, in step S3, the linear interpolation relationship calculated by linear interpolation is:

[0018] K rg =K rs (1-y)+yK rn

[0019] Where K rg is the gas phase permeability of mixed steam and non-condensable gas, K rs is the gas phase permeability corresponding to steam, K rn is the gas phase permeability corresponding to the non-condensable gas, and y is the mole fraction of the non-condensable gas in the gas phase.

[0020] In some embodiments of the present invention, in step S3, the exponential interpolation relationship calculated by exponential interpolation is:

[0021] K rg =K rs (1-x)+yK m

[0022]

[0023] x=a n

[0024] Where K rg K is the gas phase permeability of mixed steam and non-condensable gas; rs is the gas phase permeability corresponding to steam, K rn is the gas phase permeability corresponding to the non-condensable gas; y is the mole fraction of the non-condensable gas in the gas phase; n is the index.

[0025] According to a second aspect of an embodiment of the present invention, a processing device for non-condensable gas-assisted SAGD numerical simulation is provided, wherein the processing device for non-condensable gas-assisted SAGD numerical simulation comprises:

[0026] The diffusion coefficient acquisition module is used to obtain the diffusion coefficient of non-condensable gas in the gas phase by injecting non-condensable gas into saturated steam at the SAGD operating pressure through experimental testing based on the steady-state method of the Stephen diffuser.

[0027] A phase model acquisition module is used to establish non-condensable gas phase model reaction equations corresponding to non-instantaneous dissolution and non-instantaneous degassing;

[0028] The rock-fluid module is used to set the gas-liquid permeability corresponding to steam and non-condensable gas respectively, and perform interpolation calculations based on the gas phase composition. The gas-liquid permeability corresponding to steam or non-condensable gas is obtained through steady-state or unsteady-state testing, while the gas-liquid permeability of mixed steam and non-condensable gas is interpolated using linear or exponential methods.

[0029] The simulation application module is used for numerical simulation calculation of non-condensable gas assisted SAGD production based on the obtained diffusion coefficient, non-condensable gas phase model reaction equation, steam and corresponding gas-liquid permeability of non-condensable gas.

[0030] In some embodiments of the present invention, the phase model acquisition module establishes a non-instantaneous dissolved non-condensable gas phase model reaction formula comprising:

[0031] In the dissolution process of non-condensable gas into bubbles, it is defined as Also define the dissolution rate Where A1 is the first reaction frequency factor, E a1 is the first activation energy, RT is room temperature, the first reaction frequency factor A1 is 1.64E+7, the first activation energy E a1 It is 4736.5J / mole.

[0032] In some embodiments of the present invention, the phase model acquisition module establishes a non-instantaneous degassing non-condensable gas phase model reaction formula comprising:

[0033] In the degassing process of non-condensable gas, bubbles coalesce into free gas as the temperature and pressure change, which is defined as Also define the dissolution rate Where A2 is the second reaction frequency factor, E a2 is the second activation energy, RT is room temperature, the second reaction frequency factor A2 is 1.0E-3 to 5.0E-3, and the second activation energy E a2 is 0.

[0034] In some embodiments of the present invention, the linear interpolation relationship calculated by the rock-fluid module through linear interpolation is:

[0035] K rg =K rs (1-y)+yK rn

[0036] Where K rg is the gas phase permeability of mixed steam and non-condensable gas, K rs is the gas phase permeability corresponding to steam, K rn is the gas phase permeability corresponding to the non-condensable gas, and y is the mole fraction of the non-condensable gas in the gas phase.

[0037] In some embodiments of the present invention, the exponential interpolation relationship calculated by the rock-fluid module through exponential interpolation is:

[0038] K rg =K rs (1-x)+yK m

[0039]

[0040] x=a n

[0041] Where K rg K is the gas phase permeability of mixed steam and non-condensable gas; rs is the gas phase permeability corresponding to steam, K rn is the gas phase permeability corresponding to the non-condensable gas; y is the mole fraction of the non-condensable gas in the gas phase; n is the index.

[0042] The technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0043] An embodiment of the present invention provides a processing method and device for non-condensable gas assisted SAGD numerical simulation. The processing method for non-condensable gas assisted SAGD numerical simulation of the present invention greatly improves the numerical simulation results by defining the diffusion coefficient of non-condensable gas in the gas phase, introducing the phase model reaction equations of non-instantaneous dissolution and non-instantaneous degassing, and setting different gas-liquid permeabilities for steam and non-condensable gas. It reduces the adhesion concentration of non-condensable gas at the discharge boundary of the entire steam chamber, avoids excessive accumulation of non-condensable gas at the discharge boundary of the steam chamber, thereby reducing the obstruction of non-condensable gas to the expansion of the steam chamber and oil production, and realizes that the mixed injection of non-condensable gas greatly reduces the steam volume without significantly reducing the oil production. It is more consistent with experimental tests and on-site monitoring, and can better provide a reference for guiding development and optimization design.

[0044] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 A schematic flow chart of a processing method for non-condensate gas assisted SAGD numerical simulation provided by an embodiment of the present invention;

[0047] Figure 2 A reference diagram of the gas-liquid relative permeability curve corresponding to steam under different temperature conditions after SAGD history fitting;

[0048] Figure 3 This is a reference diagram of the gas-liquid permeability curve corresponding to methane under different temperature conditions measured based on the non-steady-state method;

[0049] Figure 4 A reference diagram comparing the gas phase diffusion coefficient introduced in the present invention with the traditional method regarding the methane mole fraction in the gas phase, the steam mole fraction in the gas phase, and the steam chamber temperature field;

[0050] Figure 5 A reference diagram of the comparison curves of the gas phase diffusion coefficient, SAGD and traditional methods is introduced for the present invention;

[0051] Figure 6 A reference diagram of the comparison curve of the gas phase diffusion coefficient, SAGD and traditional methods is introduced for the present invention;

[0052] Figure 7 A reference diagram comparing the non-instantaneous dissolution degassing mechanism introduced in the present invention with the traditional method regarding the methane mole fraction in the gas phase, the steam mole fraction in the gas phase, and the temperature field in the steam chamber;

[0053] Figure 8 A reference diagram of the daily oil production comparison curves of the non-instantaneous dissolution degassing mechanism introduced in the present invention and SAGD and traditional methods;

[0054] Figure 9 A reference diagram of the comparison curve of the non-instantaneous dissolution degassing mechanism introduced in the present invention and the daily steam injection of SAGD and the traditional method;

[0055] Figure 10 A reference diagram comparing the methane mole fraction in the gas phase, the steam mole fraction in the gas phase, and the steam chamber temperature field using different gas phase permeation methods introduced in the present invention and the traditional method;

[0056] Figure 11 The present invention introduces a reference diagram of the daily oil production comparison curve of different gas phase permeabilities and SAGD and traditional methods;

[0057] Figure 12 A reference diagram of the daily steam injection comparison curves of different gas phase permeabilities, SAGD, and traditional methods is introduced for the present invention;

[0058] Figure 13 A schematic diagram showing a comparison between the comprehensive simulation of the present invention and the traditional method regarding the methane mole fraction in the gas phase, the steam mole fraction in the gas phase, and the temperature field in the steam chamber;

[0059] Figure 14 A reference diagram for comparing daily oil production curves under the conditions of co-injection of methane by SAGD, conventional methods and the present invention;

[0060] Figure 15A reference diagram of daily steam injection curves for comparison between SAGD, conventional methods, and the present invention under the conditions of mixed methane injection;

[0061] Figure 16 A schematic diagram of the principle structure of a processing device for non-condensable gas assisted SAGD numerical simulation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0062] Exemplary embodiments of the present disclosure will be described below in more detail with reference to the accompanying drawings.

[0063] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments of the present disclosure. These figures are not drawn to scale, and for the purpose of clarity, certain details are exaggerated and certain details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0064] In the context of this disclosure, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element or an intervening layer / element may exist therebetween. Additionally, if a layer / element is "on" another layer / element in one orientation, the layer / element may be "below" the other layer / element when the orientation is reversed. In the context of this disclosure, similar or identical components may be denoted by the same or similar reference numerals.

[0065] In order to better understand the above technical solution, the above technical solution will be described in detail below in combination with specific implementation methods. It should be understood that the embodiments of the present disclosure and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0066] Figure 1 FIG. 1 is a flow chart of a processing method for non-condensate gas assisted SAGD numerical simulation provided by an embodiment of the present invention, such as Figure 1 As shown, the processing method for the non-condensate gas assisted SAGD numerical simulation includes:

[0067] S1. Steady-state method based on Stephen diffuser: Through experimental testing, non-condensable gas is mixed into saturated steam at SAGD operating pressure to obtain the diffusion coefficient of non-condensable gas in the gas phase;

[0068] The diffusion coefficient of the non-condensable gas in the gas phase obtained in step S1 is obtained by injecting the non-condensable gas into saturated steam at the SAGD operating pressure through experimental testing based on the steady-state method of the Stephen diffuser. In the numerical simulation of condensable gas-assisted SAGD, it can better reflect the stronger penetrability of the non-condensable gas, reduce the adhesion concentration of the non-condensable gas at the discharge boundary of the entire steam chamber, and thus reduce the obstruction of the non-condensable gas to the expansion of the steam chamber and oil production.

[0069] S2. Establishing non-condensable gas phase model reaction formulas corresponding to non-instantaneous dissolution and non-instantaneous degassing respectively; in an embodiment of the present invention, in step S2, establishing the non-condensable gas phase model reaction formula of non-instantaneous dissolution includes:

[0070] In the dissolution process of non-condensable gas into bubbles, it is defined as Also define the dissolution rate Where A1 is the first reaction frequency factor, E a1 is the first activation energy, RT is room temperature, the first reaction frequency factor A1 is 1.64E+7, the first activation energy E a1 It is 4736.5J / mole.

[0071] In an embodiment of the present invention, in step S2, establishing a non-instantaneous degassing non-condensable gas phase model reaction formula includes:

[0072] In the degassing process of non-condensable gas, bubbles coalesce into free gas as the temperature and pressure change, which is defined as Also define the dissolution rate Where A2 is the second reaction frequency factor, E a2 is the second activation energy, RT is room temperature, the second reaction frequency factor A2 is 1.0E-3 to 5.0E-3, and the second activation energy E a2 is 0.

[0073] Step S2 establishes a non-instantaneous dissolution non-condensable gas phase model reaction formula and a non-instantaneous degassing non-condensable gas phase model reaction formula, which is more consistent with the actual situation of dissolution and separation of non-condensable gas in heavy oil, and at the same time reduces the adhesion concentration of non-condensable gas at the entire steam chamber discharge boundary, thereby reducing the obstruction of non-condensable gas to steam chamber expansion and oil production.

[0074] S3. Set the gas-liquid permeability corresponding to steam and non-condensable gas respectively, and perform interpolation calculations based on the gas phase composition. The gas-liquid permeability corresponding to steam or non-condensable gas is obtained through steady-state or unsteady-state testing. The gas-liquid permeability of mixed steam and non-condensable gas is interpolated using a linear or exponential formula.

[0075] In an embodiment of the present invention, in step S3, the gas-liquid permeability corresponding to steam or non-condensable gas can be tested by a steady-state method or a non-steady-state method, and gas-phase permeability tests under different temperature conditions can be performed, and gas-phase permeability under different temperature conditions can be set in the numerical simulation; in other embodiments of the present invention, the residual oil saturation Sor determined by core saturation logging (RST) can also be combined with the residual oil saturation Sor determined by linear, exponential or polynomial relationship to perform extrapolation correction. Step S3, by setting different gas-liquid permeabilities for steam and non-condensable gas, can better reflect the difference in the effects of steam and non-condensable gas on rock fluids (including non-condensable gas fingering, insulation, convective heat transfer and low permeability reservoir production conditions, etc.), which helps to expand the non-condensable gas swept volume and oil displacement efficiency, and increase oil production.

[0076] In an embodiment of the present invention, in step S3, the linear interpolation relationship calculated by linear interpolation is:

[0077] K rg =K rs (1-y)+yK rn

[0078] Where K rg is the gas phase permeability of mixed steam and non-condensable gas, K rs is the gas phase permeability corresponding to steam, K rn is the gas phase permeability corresponding to the non-condensable gas, and y is the mole fraction of the non-condensable gas in the gas phase.

[0079] In an embodiment of the present invention, in step S3, the exponential interpolation relationship calculated by exponential interpolation is:

[0080] K rg =K rs (1-x)+yK m

[0081]

[0082] x=a n

[0083] Where K rg K is the gas phase permeability of mixed steam and non-condensable gas; rs is the gas phase permeability corresponding to steam, K rn is the gas phase permeability corresponding to the non-condensable gas; y is the mole fraction of the non-condensable gas in the gas phase; n is an exponent, and when n=1, it is converted to a linear interpolation.

[0084] S4. Numerical simulation of non-condensable gas assisted SAGD production is performed based on the obtained diffusion coefficient, non-condensable gas phase model reaction equation, steam, and corresponding gas-liquid permeability of non-condensable gas.

[0085] The embodiment of the present invention is based on the conventional traditional numerical simulation method to define the gas-liquid K value (phase equilibrium constant) and liquid-liquid K value (phase equilibrium constant) corresponding to the non-condensable gas, liquid phase properties (density, compressibility, etc.), viscosity-temperature data, injection ratio definition and other parameter settings, and is based on the diffusion coefficient obtained in steps S1-S3, the non-condensable gas phase model reaction equation, steam and the corresponding gas-liquid phase permeability of the non-condensable gas for numerical simulation of non-condensable gas assisted SAGD production, overcoming the problem of the existing numerical simulation method that the non-condensable gas accumulates at the steam chamber discharge boundary, hindering the expansion of the steam chamber and reducing oil production.

[0086] For example, the non-condensable gas methane injected into the model by a single well in an oil sand SAGD block is studied. Based on the CMG software STARS module, the relevant numerical simulation settings are improved, and five components, including water, bitumen, CH4O, CH4, and CH4G, are considered. The specific process is shown in the following reference:

[0087] The diffusion coefficient of methane in steam was determined to be 3E-5 m by the steady-state method based on the Stephan diffusion tube. 2 / s(corresponding to 2.592m 2 / d), the digital model file settings are as follows:

[0088] **The following is the diffusion coefficient setting of methane in the gas phase in the three directions IJK

[0089] *DIFFI_GAS'CH4'*CON 2.592

[0090] *DIFFJ_GAS'CH4'*CON 2.592

[0091] *DIFFK_GAS'CH4'*CON 2.592

[0092] Considering the foam oil mechanism, the phase model reaction equations of non-instantaneous dissolution and non-instantaneous degassing are introduced, and the numerical model file settings are shown as follows:

[0093] **The following is the dissolution process of "non-condensable gas into bubbles": 1CH4 ==> 1CH4O

[0094] STOREAC 0 0 0 1 0

[0096] STOPROD 0 0 1 0 0

[0098] RPHASE 0 0 0 3 0

[0100] RORDER 0 0 0 1 0

[0102] **The following are the reaction frequency factors and activation energy settings related to the reaction rate R1

[0103] FREQFAC 1.64e+7

[0104] EACT 4736.5

[0105] **The following is the degassing process of "small bubbles coalescing into free gas" with changes in temperature and pressure: 1CH4O ==> 1CH4G

[0106] STOREAC 0 0 1 0 0

[0108] STOPROD 0 0 0 0 1

[0110] RPHASE 0 0 2 0 0

[0112] RORDER 0 0 1 0 0

[0114] **The following are the reaction frequency factors and activation energy settings related to the reaction rate R2

[0115] FREQFAC 1.75E-3

[0116] EACT 0

[0117] Steam follows the gas-liquid permeability after SAGD history fitting, see Figure 2 As shown, Figure 2 The reference diagram of the gas-liquid permeability curve of steam under different temperature conditions after SAGD history fitting is shown in Figure 2. The gas-liquid permeability curve of methane is measured by the non-steady-state method. Figure 3 As shown, Figure 3 This is a reference diagram of the gas-liquid permeability curves for methane under different temperature conditions measured based on the non-steady-state method. Steam and non-condensable gas require different gas-liquid permeabilities and are interpolated based on the gas phase composition. The numerical simulation file settings are shown below for reference:

[0118] RPT 1STONE2 WATWET

[0119] *INTCOMP'CH4'*Gas

[0120] KRINTRP 1** Oil-water phase permeability and steam corresponding gas phase permeability

[0121] *DTRAPN 0.0

[0122] SWT

[0123] …

[0124] SLT

[0125] …

[0126] KRINTRP 2** Oil-water phase permeability and gas phase permeability corresponding to methane

[0127] *DTRAPN 1.0

[0128] SWT

[0129] …

[0130] SLT

[0131] …

[0132] Comparing the simulation of SAGD (single steam injection), the traditional simulation method and the different settings of the present invention involving the injection of 2 mol% methane after 5 years of SAGD production, the methane mole fraction in the gas phase, the steam mole fraction in the gas phase and the steam chamber temperature field, the daily oil production and daily steam injection curves are shown as follows: Figures 4 to 15 shown.

[0133] like Figures 4 to 6 As shown, Figure 4 A reference diagram comparing the gas phase diffusion coefficient introduced in the present invention with the traditional method regarding the methane mole fraction in the gas phase, the steam mole fraction in the gas phase, and the steam chamber temperature field is provided. Figure 5 The present invention introduces a reference diagram of the gas phase diffusion coefficient and the daily oil production comparison curve of SAGD and traditional methods. Figure 6 This is a reference diagram of the comparison curve of the daily steam injection of SAGD and traditional methods using the gas phase diffusion coefficient introduced in the present invention. For the mixed non-condensable gas injection technology, compared with the traditional simulation method, after the gas phase diffusion coefficient is introduced in the present invention, the adhesion concentration of non-condensable gas at the discharge boundary of the entire steam chamber is significantly reduced. The mixed natural gas injection causes an average increase of 17% in oil production, while having little effect on the steam injection amount, which only increases by 3%.

[0134] like Figures 7 to 9 As shown, Figure 7 A reference diagram comparing the methane mole fraction in the gas phase, the steam mole fraction in the gas phase, and the steam chamber temperature field using the non-instantaneous dissolution degassing mechanism introduced in the present invention and the traditional method is provided. Figure 8 This is a reference diagram of the daily oil production comparison curve of the non-instantaneous dissolution degassing mechanism introduced in the present invention and SAGD and traditional methods. Figure 9 The reference diagram of the daily steam injection comparison curve of the non-instantaneous dissolution and degassing mechanism introduced in the present invention and SAGD and the traditional method shows that, compared with the traditional method considering instantaneous dissolution and degassing, after the foam oil-like mechanism is introduced in the present invention, the adhesion concentration of non-condensable gas at the discharge boundary of the entire steam chamber is significantly reduced, the oil production is increased by 70%, and the steam injection amount is increased by 9%.

[0135] like Figures 10 to 12 As shown, Figure 10 The present invention introduces a reference diagram comparing the methane mole fraction in the gas phase, the steam mole fraction in the gas phase and the steam chamber temperature field with the traditional method. Figure 11 The present invention introduces a reference diagram of the daily oil production comparison curve of different gas phase permeabilities, SAGD, and traditional methods. Figure 12 The present invention introduces a reference schematic diagram of the comparison curve of different gas phase permeabilities with SAGD and traditional methods of daily steam injection. Compared with the traditional method in which both steam and natural gas use UTF history fitting for gas phase permeability, the present invention uses UTF history fitting for gas phase permeability and experimental test for gas-liquid permeability for steam and natural gas, respectively. The oil production increases by 14%, while the steam production increases by only 3%.

[0136] like Figures 13 to 15 As shown, Figure 13 This is a reference diagram comparing the comprehensive simulation of the present invention with the traditional method regarding the methane mole fraction in the gas phase, the steam mole fraction in the gas phase, and the steam chamber temperature field. Figure 14 A reference diagram of the daily oil production curve under the conditions of mixed methane injection is provided to compare SAGD, the traditional method and the present invention. Figure 15 To compare the daily steam injection curve reference diagram under the mixed methane injection conditions simulated by SAGD, traditional methods and the present invention, after comprehensively applying the above-mentioned mechanism description, the present invention shows that compared with the traditional mixed non-condensable gas simulation method, the adhesion concentration of non-condensable gas at the discharge boundary of the entire steam chamber is significantly reduced, the oil production is increased by 98%, and the steam injection amount is increased by 10%; compared with SAGD, the oil production is only reduced by 8% after mixed injection of 2 mol% natural gas, and the steam injection amount is reduced by 69%, achieving a significant reduction in steam injection amount while having little adverse effect on oil production, which is closer to and matches the existing experiments and field observations of analog projects.

[0137] The processing method for non-condensable gas assisted SAGD numerical simulation described in the embodiment of the present invention greatly improves the numerical simulation results by defining the diffusion coefficient of non-condensable gas in the gas phase, introducing the phase model reaction equations of non-instantaneous dissolution and non-instantaneous degassing, and setting different gas-liquid permeabilities for steam and non-condensable gas. It reduces the adhesion concentration of non-condensable gas at the discharge boundary of the entire steam chamber, avoids the accumulation of non-condensable gas at the discharge boundary of the steam chamber, thereby reducing the obstruction of non-condensable gas to the expansion of the steam chamber and oil production, and achieves the mixed injection of non-condensable gas to significantly reduce the steam volume without significantly reducing the oil production. It is more consistent with experimental tests and field monitoring, and can better provide a reference for guiding development and optimization design.

[0138] Based on the above embodiments, the present invention further provides a processing device for non-condensable gas-assisted SAGD numerical simulation, which is applied to the processing method for non-condensable gas-assisted SAGD numerical simulation described in any of the above embodiments. The processing device for non-condensable gas-assisted SAGD numerical simulation includes:

[0139] The diffusion coefficient acquisition module 100 is used to obtain the diffusion coefficient of the non-condensable gas in the gas phase by injecting the non-condensable gas into saturated steam at the SAGD operating pressure through experimental testing based on the steady-state method of the Stephen diffuser;

[0140] Phase model acquisition module 200, for establishing non-condensable gas phase model reaction equations corresponding to non-instantaneous dissolution and non-instantaneous degassing respectively;

[0141] The rock-fluid module 300 is used to set the gas-liquid permeability corresponding to steam and non-condensable gas, and perform interpolation calculations based on the gas phase composition. The gas-liquid permeability corresponding to steam or non-condensable gas is obtained through steady-state or unsteady-state testing. The gas-liquid permeability of mixed steam and non-condensable gas is interpolated using a linear or exponential formula.

[0142] The simulation application module 400 is used for numerical simulation calculation of non-condensable gas assisted SAGD production based on the obtained diffusion coefficient, non-condensable gas phase model reaction equation, steam and corresponding gas-liquid permeability of non-condensable gas.

[0143] In an embodiment of the present invention, the phase model acquisition module 200 establishes a non-instantaneous dissolved non-condensable gas phase model reaction formula including:

[0144] In the dissolution process of non-condensable gas into bubbles, it is defined as Also define the dissolution rate Where A1 is the first reaction frequency factor, E a1 is the first activation energy, RT is room temperature, the first reaction frequency factor A1 is 1.64E+7, the first activation energy E a1 It is 4736.5J / mole.

[0145] In an embodiment of the present invention, the phase model acquisition module 200 establishes a non-instantaneous degassing non-condensable gas phase model reaction formula including:

[0146] In the degassing process of non-condensable gas, bubbles coalesce into free gas as the temperature and pressure change, which is defined as Also define the dissolution rate Where A2 is the second reaction frequency factor, E a2 is the second activation energy, RT is room temperature, the second reaction frequency factor A2 is 1.0E-3 to 5.0E-3, and the second activation energy E a2is 0.

[0147] In an embodiment of the present invention, the linear interpolation relationship calculated by the rock-fluid module 300 through linear interpolation is:

[0148] K rg =K rs (1-y)+yK rn

[0149] Where K rg is the gas phase permeability of mixed steam and non-condensable gas, K rs is the gas phase permeability corresponding to steam, K rn is the gas phase permeability corresponding to the non-condensable gas, and y is the mole fraction of the non-condensable gas in the gas phase.

[0150] In an embodiment of the present invention, the exponential interpolation relationship calculated by the rock-fluid module 300 through exponential interpolation is:

[0151] K rg =K rs (1-x)+yK m

[0152]

[0153] x=a n

[0154] Where K rg K is the gas phase permeability of mixed steam and non-condensable gas; rs is the gas phase permeability corresponding to steam, K rn is the gas phase permeability corresponding to the non-condensable gas; y is the mole fraction of the non-condensable gas in the gas phase; n is an exponent, and when n=1, it is converted to a linear interpolation.

[0155] The processing device for non-condensable gas assisted SAGD numerical simulation described in the embodiment of the present invention can execute the processing method for non-condensable gas assisted SAGD numerical simulation provided in the above embodiment. The processing device for non-condensable gas assisted SAGD numerical simulation has the corresponding functional steps and beneficial effects of the processing method for non-condensable gas assisted SAGD numerical simulation described in the above embodiment. Please refer to the embodiment of the above-mentioned processing method for non-condensable gas assisted SAGD numerical simulation for details. The embodiment of the present invention will not be repeated here.

[0156] An embodiment of the present invention further provides an electronic device, which may include a processor and a memory, wherein the processor and the memory may be connected via a bus or other means. The processor may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a combination of the above chips. The memory, as a non-transient computer-readable storage medium, may be used to store non-transient software programs, non-transient computer executable programs, and modules, such as the program instructions / modules corresponding to the processing method for the non-condensate gas-assisted SAGD numerical simulation in the embodiment of the present invention. The processor executes various functional applications and data processing of the processor by running the non-transient software programs, instructions, and modules stored in the memory, thereby implementing the processing method for the non-condensate gas-assisted SAGD numerical simulation in the above method embodiment.

[0157] The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating system and applications required for at least one function; the data storage area may store data created by the processor, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. The one or more modules are stored in the memory, and when executed by the processor, the execution is as follows: Figure 1 The processing method of the non-condensate gas assisted SAGD numerical simulation in the embodiment shown. Figure 1The corresponding descriptions and effects in the embodiments shown are understood and will not be repeated here. Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the storage medium can be a read-only memory (ROM), a random access memory (RAM), a flash memory (Flash Memory), a hard disk (HDD) or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above-mentioned types of memory.

[0158] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0159] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the claims below, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Accordingly, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of the invention.

[0160] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims.

Claims

1. A method for numerical simulation of non-condensate gas assisted SAGD, characterized in that: The processing method for the non-condensable gas assisted SAGD numerical simulation includes: S1. Steady-state method based on Stephen diffuser: Through experimental testing, non-condensable gas is mixed into saturated steam at SAGD operating pressure to obtain the diffusion coefficient of non-condensable gas in the gas phase; S2. Establish the non-condensable gas phase model reaction equations corresponding to non-instantaneous dissolution and non-instantaneous degassing respectively; S3. Set the gas-liquid permeability corresponding to steam and non-condensable gas respectively, and perform interpolation calculations based on the gas phase composition. The gas-liquid permeability corresponding to steam or non-condensable gas is obtained through steady-state or unsteady-state testing. The gas-liquid permeability of mixed steam and non-condensable gas is interpolated using a linear or exponential formula. S4. Numerical simulation calculations for non-condensable gas assisted SAGD production are performed based on the obtained diffusion coefficient, non-condensable gas phase model reaction equation, steam, and corresponding gas-liquid permeability of non-condensable gas.

2. The method for non-condensate gas assisted SAGD numerical simulation according to claim 1, characterized in that: In step S2, the reaction formula for establishing a non-instantaneous dissolved non-condensable gas phase model includes: In the dissolution process of non-condensable gas into bubbles, it is defined as Also define the dissolution rate Where A1 is the first reaction frequency factor, E a1 is the first activation energy, RT is room temperature, the first reaction frequency factor A1 is 1.64E+7, the first activation energy E a1 It is 4736.5J / mole.

3. The method for non-condensable gas assisted SAGD numerical simulation according to claim 2, characterized in that: In step S2, the reaction equation for establishing a non-instantaneous degassing non-condensable gas phase model includes: In the degassing process of non-condensable gas, bubbles coalesce into free gas as the temperature and pressure change, which is defined as Also define the dissolution rate Where A2 is the second reaction frequency factor, E a2 is the second activation energy, RT is room temperature, the second reaction frequency factor A2 is 1.0E-3 to 5.0E-3, and the second activation energy E a2 is 0.

4. The method for non-condensate gas assisted SAGD numerical simulation according to claim 1, characterized in that: In step S3, the linear interpolation relationship calculated by linear interpolation is: K rg =K rs (1-y)+yK rn Where K rg is the gas phase permeability of mixed steam and non-condensable gas, K rs is the gas phase permeability corresponding to steam, K rn is the gas phase permeability corresponding to the non-condensable gas, and y is the mole fraction of the non-condensable gas in the gas phase.

5. The processing method for non-condensable gas assisted SAGD numerical simulation according to claim 4, characterized in that: In step S3, the exponential interpolation relationship calculated by exponential interpolation is: K rg =K rs (1-x)+yK m x=a n Where K rg K is the gas phase permeability of mixed steam and non-condensable gas; rs is the gas phase permeability corresponding to steam, K rn is the gas phase permeability corresponding to the non-condensable gas; y is the mole fraction of the non-condensable gas in the gas phase; n is the index.

6. A processing device for non-condensate gas assisted SAGD numerical simulation, characterized in that: The processing device for the non-condensable gas assisted SAGD numerical simulation includes: The diffusion coefficient acquisition module is used to obtain the diffusion coefficient of non-condensable gas in the gas phase by injecting non-condensable gas into saturated steam at the SAGD operating pressure through experimental testing based on the steady-state method of the Stephen diffuser. A phase model acquisition module is used to establish non-condensable gas phase model reaction equations corresponding to non-instantaneous dissolution and non-instantaneous degassing; The rock-fluid module is used to set the gas-liquid permeability corresponding to steam and non-condensable gas respectively, and perform interpolation calculations based on the gas phase composition. The gas-liquid permeability corresponding to steam or non-condensable gas is obtained through steady-state or unsteady-state testing, while the gas-liquid permeability of mixed steam and non-condensable gas is interpolated using linear or exponential methods. The simulation application module is used for numerical simulation calculation of non-condensable gas assisted SAGD production based on the obtained diffusion coefficient, non-condensable gas phase model reaction equation, steam and corresponding gas-liquid permeability of non-condensable gas.

7. The processing device for non-condensable gas assisted SAGD numerical simulation according to claim 6, characterized in that: The phase model acquisition module establishes a non-instantaneous dissolved non-condensable gas phase model reaction formula including: In the dissolution process of non-condensable gas into bubbles, it is defined as Also define the dissolution rate Where A1 is the first reaction frequency factor, E a1 is the first activation energy, RT is room temperature, the first reaction frequency factor A1 is 1.64E+7, the first activation energy E a1 It is 4736.5J / mole.

8. The processing device for non-condensable gas assisted SAGD numerical simulation according to claim 7, characterized in that: The phase model acquisition module establishes a non-instantaneous degassing non-condensable gas phase model reaction formula including: In the degassing process of non-condensable gas, bubbles coalesce into free gas as the temperature and pressure change, which is defined as Also define the dissolution rate Where A2 is the second reaction frequency factor, E a2 is the second activation energy, RT is room temperature, the second reaction frequency factor A2 is 1.0E-3 to 5.0E-3, and the second activation energy E a2 is 0.

9. The processing device for non-condensable gas assisted SAGD numerical simulation according to claim 6, characterized in that: The linear interpolation relationship calculated by the rock-fluid module through linear interpolation is: K rg =K rs (1-y)+yK rn Where K rg is the gas phase permeability of mixed steam and non-condensable gas, K rs is the gas phase permeability corresponding to steam, K rn is the gas phase permeability corresponding to the non-condensable gas, and y is the mole fraction of the non-condensable gas in the gas phase.

10. The processing device for non-condensable gas assisted SAGD numerical simulation according to claim 9, characterized in that: The exponential interpolation relationship calculated by the rock-fluid module through exponential interpolation is: K rg =K rs (1-x)+yK m x=a n Where K rg K is the gas phase permeability of mixed steam and non-condensable gas; rs is the gas phase permeability corresponding to steam, K rn is the gas phase permeability corresponding to the non-condensable gas; y is the mole fraction of the non-condensable gas in the gas phase; n is the index.

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