阅读说明：本技术 一种基于气水交替驱油的井距设计方法、装置及设备 (Well spacing design method, device and equipment based on gas-water alternating oil displacement ) 是由 第五鹏祥 赵乐坤 刘同敬 侯刚刚 赵文越 刘睿 周建 倪娟 卢政佚 韩富强 史恒 于 2021-08-04 设计创作，主要内容包括：本说明书实施例提供一种基于气水交替驱油的井距设计方法、装置及设备。所述方法包括：获取驱替生产参数；所述驱替生产参数用于表示对应于气驱过程和/或水驱过程的参数；利用所述驱替生产参数计算校正系数；所述校正系数用于表示基于驱替效果对驱替生产参数进行校正的参数；基于所述校正系数计算采收率；所述采收率用于描述驱替生产过程的开发效果；根据采收率确定对应于目标储层的经济优化井距；所述经济优化井距用于表示生产收益最大化时对应的井距；基于所述经济优化井距和储层参数确定目标井距。上述方法确定符合实际需要的井距,从而同时保证了经济收益和施工难度,提高了开采效率,对基于气水交替驱的油藏的开发做出了重要的指导。(The embodiment of the specification provides a well spacing design method, a device and equipment based on gas-water alternating oil displacement. The method comprises the following steps: acquiring displacement production parameters; the displacement production parameter is used for representing a parameter corresponding to a gas flooding process and/or a water flooding process; calculating a correction coefficient by using the displacement production parameter; the correction coefficient is used for representing a parameter for correcting the displacement production parameter based on the displacement effect; calculating a recovery factor based on the correction factor; the recovery factor is used for describing the development effect of the displacement production process; determining an economically optimized well spacing corresponding to the target reservoir based on the recovery factor; the economic optimization well spacing is used for representing the corresponding well spacing when the production yield is maximized; a target well spacing is determined based on the economically optimized well spacing and the reservoir parameters. The method determines the well spacing meeting the actual requirement, thereby simultaneously ensuring the economic benefit and the construction difficulty, improving the exploitation efficiency and providing important guidance for the development of the oil reservoir based on the gas-water alternative flooding.)

1. A well spacing design method based on gas-water alternating oil displacement is characterized by comprising the following steps of:

acquiring displacement production parameters; the displacement production parameter is used for representing a parameter corresponding to a gas flooding process and/or a water flooding process;

calculating a correction coefficient by using the displacement production parameter; the correction coefficient is used for representing a parameter for correcting the displacement production parameter based on the displacement effect;

calculating a recovery factor based on the correction factor; the recovery factor is used for describing the development effect of the displacement production process;

determining an economically optimized well spacing corresponding to the target reservoir based on the recovery factor; the economic optimization well spacing is used for representing the corresponding well spacing when the production yield is maximized;

a target well spacing is determined based on the economically optimized well spacing and the reservoir parameters.

2. The method of claim 1, wherein the correction coefficients include a gas injection amount correction coefficient and a fluidity ratio correction coefficient; the calculating of the correction coefficient by using the displacement production parameter comprises the following steps:

using formula V_i＝ai²+ bi + c calculating the gas injection correction factor, where V_iThe correction coefficient is the gas injection quantity, i is the mass ratio of the injected gas in the slug, and a, b and c are characterization function coefficients;

using formulasCalculating a fluidity ratio correction factor, wherein C_iAs fluidity ratio correction factor, m_CO2Mass fraction of injected gas m in the process of gas-water alternating injection_waterThe mass fraction of the injected water in the process of alternately injecting the gas and the water.

3. The method of claim 2, wherein said calculating a recovery factor based on said correction factor comprises:

using formulasCalculated recovery ratio of formula (II) E_RFor recovery of oil, V_kIs a vertical anisotropic coefficient, k is permeability, C_iIs a fluidity ratio correction coefficient, M is a fluidity ratio, n is a well pattern density,wherein P is the formation pressure, P_MMPTo minimum miscible pressure, E_PV＝0.3872(V_i×PV)³-1.2521(V_i×PV)²+1.763V_iX PV +0.0136, wherein V_iPV is the ratio of injected volume to total pore volume for gas injection correction factor.

4. The method of claim 1, wherein determining an economically optimized well spacing corresponding to a target reservoir from a recovery factor comprises:

using formulasCalculating the density of the well pattern, wherein P is the selling price of the crude oil, C is the measure cost of the crude oil, N is the geological reserve, E_RFor recovery, n is the well pattern density, M is the total investment of a single well, and A is the oil-bearing area;

determining an economically optimized well spacing corresponding to a target reservoir from the pattern density.

5. The method of claim 1, wherein determining a target well spacing based on the economically optimized well spacing and reservoir parameters comprises:

obtaining a well spacing design chart according to the economic optimization well spacing; the well spacing design plate is used for describing the change condition of the economic optimization well spacing under different stratum thicknesses and different permeabilities;

determining a target well spacing in the well spacing design plate based on the reservoir parameters.

6. The method of claim 5, wherein the well spacing design plate further comprises an annual fluid production rate profile; the annual liquid production speed curve is used for representing the change situation of the liquid production speed along with the thickness of the stratum under the conditions of different permeability;

the liquid extraction speed in the liquid extraction speed curve is obtained through the following modes: using formulasCalculating the fluid-collecting speed, wherein V_aThe annual fluid production speed under unit pressure difference, k is permeability, L is injection-production well spacing, phi is porosity, mu is crude oil viscosity, r is_wIs the radius of the wellbore, S_oIs the original oil saturation.

7. The method of claim 6, wherein determining a target well spacing in the well spacing design plate based on the reservoir parameters comprises:

using formulasCalculating a target well spacing, wherein L_{Reasonable and reasonable}At a target well spacing, Δ Q₁Is the initial annual fluid production rate, Δ Q, per unit pressure difference₂Is the expected annual fluid production rate, L, per unit pressure difference_{Optimization of}The well spacing is optimized for economy.

8. The method of claim 5, wherein the well spacing design plate further comprises an economic threshold well spacing; the economic limit well spacing is used for limiting the minimum value of the well spacing; the economic limit well spacing is obtained by the following method:

using the formula (P-C) XNXE_RCalculating economic limit well spacing of (M x A x n-G x PV ═ 0), wherein P is crude oil pinPrice, C crude oil measure cost, N geological reserve, E_RFor recovery, M is the total investment per well, A is the oil bearing area, n is the well pattern density, G is the displacement gas price, and PV is the ratio of the injection volume to the total pore volume.

9. The utility model provides a well spacing design device based on gas-water displacement of reservoir oil in turn which characterized in that includes:

the displacement production parameter acquisition module is used for acquiring displacement production parameters; the displacement production parameter is used for representing a parameter corresponding to a gas flooding process and/or a water flooding process;

the correction coefficient calculation module is used for calculating a correction coefficient by using the displacement production parameter; the correction coefficient is used for representing a parameter for correcting the displacement production parameter based on the displacement effect;

the recovery factor evaluation model building module is used for calculating the recovery factor based on the correction coefficient; the recovery factor is used for describing the development effect of the displacement production process;

the economic optimization well spacing determination module is used for determining economic optimization well spacing corresponding to the target reservoir according to the recovery ratio; the economic optimization well spacing is used for representing the corresponding well spacing when the production yield is maximized;

and the target well spacing determination module is used for determining the target well spacing based on the economic optimization well spacing and the reservoir parameters.

10. A well spacing design device based on gas-water alternating oil displacement comprises a memory and a processor;

the memory to store computer program instructions;

the processor to execute the computer program instructions to implement the steps of: acquiring displacement production parameters; the displacement production parameter is used for representing a parameter corresponding to a gas flooding process and/or a water flooding process; calculating a correction coefficient by using the displacement production parameter; the correction coefficient is used for representing a parameter for correcting the displacement production parameter based on the displacement effect; calculating a recovery factor based on the correction factor; the recovery factor is used for describing the development effect of the displacement production process; determining an economically optimized well spacing corresponding to the target reservoir based on the recovery factor; the economic optimization well spacing is used for representing the corresponding well spacing when the production yield is maximized; a target well spacing is determined based on the economically optimized well spacing and the reservoir parameters.

Technical Field

The embodiment of the specification relates to the technical field of stratum exploration and development, in particular to a well spacing design method, device and equipment based on gas-water alternating oil displacement.

Background

The hypotonic-compact oil reservoir occupies an important proportion in oil and gas resources in China, and plays an increasingly important role in the stable and continuous development of the petroleum industry in China. However, the low-permeability and compact oil reservoir has the problems of low permeability, weak seepage capability, fast reduction of stratum energy, high difficulty in supplementing stratum energy, fast reduction of productivity and the like, and the exploitation based on the traditional mode seriously restricts the development effect of the oil reservoir. And CO₂The product has effects of improving oil-water fluidity ratio, dissolving expansion, reducing oil-water interfacial tension, and improving needleThe recovery efficiency of the low-permeability and compact oil reservoir is obviously improved.

When the traditional gas-drive oil extraction mode is used for oil extraction, the problems of early breakthrough of injected gas, low displacement efficiency and the like occur. When the gas-water alternative injection mode is adopted for exploitation, the advantages of improving the microcosmic oil displacement efficiency by gas drive and improving the macroscopic sweep efficiency by water drive are complementary, so that a synergistic effect is generated. In the gas-driven slug stage, residual oil which cannot be reached by water drive and residual oil which exists on the surface of the rock in a film form are used, so that the microcosmic oil displacement efficiency is improved. In the stage of water-driving slug, injected water blocks a gas channeling channel formed by previous gas injection, and the fingering phenomenon of gas is effectively weakened, so that the water-driving macroscopic sweep efficiency is improved.

When the exploitation is carried out in a gas-water alternative injection displacement mode, the restriction of technical and economic factors on the development cost of the oil field needs to be considered, the corresponding relation between geological parameters and well spacing needs to be considered, and the reasonable well spacing in the actual exploitation process is further comprehensively designed. Therefore, a method for designing well spacing by comprehensively considering economic factors and geological conditions in the process of gas-water alternating oil displacement is needed at present.

Disclosure of Invention

An object of an embodiment of the present specification is to provide a well spacing design method, device and equipment based on gas-water alternating flooding, so as to solve the problem of how to optimize the well spacing design in gas-water alternating flooding production to improve the production effect.

In order to solve the technical problem, an embodiment of the present specification provides a well spacing design method based on gas-water alternating flooding, including: acquiring displacement production parameters; the displacement production parameter is used for representing a parameter corresponding to a gas flooding process and/or a water flooding process; calculating a correction coefficient by using the displacement production parameter; the correction coefficient is used for representing a parameter for correcting the displacement production parameter based on the displacement effect; calculating a recovery factor based on the correction factor; the recovery factor is used for describing the development effect of the displacement production process; determining an economically optimized well spacing corresponding to the target reservoir based on the recovery factor; the economic optimization well spacing is used for representing the corresponding well spacing when the production yield is maximized; a target well spacing is determined based on the economically optimized well spacing and the reservoir parameters.

The embodiment of the present specification further provides a well spacing design device based on gas-water alternating flooding, including: the displacement production parameter acquisition module is used for acquiring displacement production parameters; the displacement production parameter is used for representing a parameter corresponding to a gas flooding process and/or a water flooding process; the correction coefficient calculation module is used for calculating a correction coefficient by using the displacement production parameter; the correction coefficient is used for representing a parameter for correcting the displacement production parameter based on the displacement effect; the recovery factor evaluation model building module is used for calculating the recovery factor based on the correction coefficient; the recovery factor is used for describing the development effect of the displacement production process; the economic optimization well spacing determination module is used for determining economic optimization well spacing corresponding to the target reservoir according to the recovery ratio; the economic optimization well spacing is used for representing the corresponding well spacing when the production yield is maximized; and the target well spacing determination module is used for determining the target well spacing based on the economic optimization well spacing and the reservoir parameters.

The embodiment of the specification also provides well spacing design equipment based on gas-water alternating oil displacement, which comprises a memory and a processor; the memory to store computer program instructions; the processor to execute the computer program instructions to implement the steps of: acquiring displacement production parameters; the displacement production parameter is used for representing a parameter corresponding to a gas flooding process and/or a water flooding process; calculating a correction coefficient by using the displacement production parameter; the correction coefficient is used for representing a parameter for correcting the displacement production parameter based on the displacement effect; calculating a recovery factor based on the correction factor; the recovery factor is used for describing the development effect of the displacement production process; determining an economically optimized well spacing corresponding to the target reservoir based on the recovery factor; the economic optimization well spacing is used for representing the corresponding well spacing when the production yield is maximized; a target well spacing is determined based on the economically optimized well spacing and the reservoir parameters.

According to the technical scheme provided by the embodiment of the specification, after the parameters in the displacement generation process are obtained, the displacement production parameters are used for calculating the correction coefficient so as to correct the displacement production process. The correction factor can then be used to calculate the recovery factor to determine the corresponding development effect and to determine an economically optimal well spacing to determine the size of the well spacing to be set when the production yield is maximized. Finally, the actual well spacing is adjusted by combining the related parameters of the reservoir, and the final target well spacing can be obtained. By the method, the well spacing meeting the actual requirement can be determined by combining the geological parameters and the economic benefit in the actual production, so that the economic benefit and the construction difficulty are ensured, the mining efficiency is improved, and important guidance is provided for the oil reservoir development based on gas-water alternative flooding.

Drawings

In order to more clearly illustrate the embodiments of the present specification or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the specification, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a flow chart of a well spacing design method based on gas-water alternating flooding in an embodiment of the present disclosure;

FIG. 2A is a schematic diagram of a well spacing design plate according to an embodiment of the present disclosure;

FIG. 2B is a schematic diagram of a well spacing design plate according to an embodiment of the present disclosure;

FIG. 2C is a schematic view of a well spacing design plate according to an embodiment of the present disclosure;

FIG. 2D is a schematic diagram of a well spacing design plate in accordance with an embodiment of the present disclosure;

FIG. 3A is a schematic diagram of a well spacing design plate according to an embodiment of the present disclosure;

FIG. 3B is a schematic diagram of a well spacing design plate according to an embodiment of the present disclosure;

FIG. 3C is a schematic view of a well spacing design plate according to an embodiment of the present disclosure;

FIG. 3D is a schematic diagram of a well spacing design plate in accordance with an embodiment of the present disclosure;

FIG. 4A is a schematic diagram of a well spacing design plate according to an embodiment of the present disclosure;

FIG. 4B is a schematic diagram of a well spacing design plate according to an embodiment of the present disclosure;

FIG. 4C is a schematic view of a well spacing design plate according to an embodiment of the present disclosure;

FIG. 4D is a schematic diagram of a well spacing design plate in accordance with an embodiment of the present disclosure;

FIG. 5 is a schematic diagram illustrating a scenario for determining a target well spacing in an embodiment of the present disclosure;

FIG. 6 is a block diagram of a well spacing design apparatus based on gas-water alternating flooding in an embodiment of the present disclosure;

fig. 7 is a structural diagram of a well spacing design device based on gas-water alternating flooding in an embodiment of the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are only a part of the embodiments of the present disclosure, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present specification without any creative effort shall fall within the protection scope of the present specification.

In order to solve the technical problem, an embodiment of the specification provides a well spacing design method based on gas-water alternating oil displacement. The execution main body of the well spacing design method based on gas-water alternating oil displacement is well spacing design equipment based on gas-water alternating oil displacement, and the well spacing design equipment based on gas-water alternating oil displacement comprises but is not limited to a server, an industrial personal computer, a PC machine and the like. As shown in fig. 1, the well spacing design method based on gas-water alternating flooding specifically may include the following steps.

S110: acquiring displacement production parameters; the displacement production parameters are used to represent parameters corresponding to a gas flooding process and/or a water flooding process.

The displacement production parameter may be a parameter indicative of a parameter corresponding to a gas flooding process and/or a water flooding process. Certain production parameters are usually corresponded in the gas drive and water drive processes, and the parameters can be used for describing construction parameters actively adopted by a constructor and can also be used for representing the change situation of corresponding geological parameters of the stratum based on the gas drive and/or water drive processes.

In some embodiments, the displacement production parameter may be at least one of a mass ratio of injected gas in the slug, a mass fraction of injected gas and injected water during the alternating gas-water injection, to more effectively enable calculation of the correction factor in subsequent steps. In practical applications, the displacement production parameters may not be limited to the above examples, and are not described herein again.

It should be noted that, based on the requirements of the actual application, the gas used in the gas flooding process may preferably be CO₂So as to ensure the effect obtained in the gas drive process.

S120: calculating a correction coefficient by using the displacement production parameter; the correction coefficient is used for representing a parameter for correcting the displacement production parameter based on the displacement effect.

After the displacement production parameters are acquired, the displacement production parameters may be utilized to calculate correction coefficients. The correction coefficient is used for correcting the displacement production parameter based on the displacement effect. In actual production, geological parameters and parameters corresponding to the production process are different to a certain extent, so that the parameters used in the actual production process need to be corrected by using a correction coefficient, and the subsequent well spacing calculation process enables the calculation result to meet relevant conditions of actual utilization.

In some embodiments, the correction factor includes a gas injection amount correction factor and a fluidity ratio correction factor. The gas injection amount correction coefficient is used for correcting relevant parameters in the gas flooding process, and the fluidity ratio correction coefficient is used for correcting relevant parameters in the water flooding process.

Based on the above embodiment, the gas injection amount correction coefficient may utilize the formula V_i＝ai²+ bi + c calculation, where V_iThe correction coefficient of the gas injection amount is obtained, i is the mass ratio of the injected gas in the slug, and a, b and c are characterization functionsA numerical coefficient.

Accordingly, the fluidity ratio correction coefficient may use a formulaCalculation of in the formula C_iAs fluidity ratio correction factor, m_CO2Mass fraction of injected gas m in the process of gas-water alternating injection_waterThe mass fraction of the injected water in the process of alternately injecting the gas and the water.

In some embodiments, after simulating "virtual development" using the reservoir value, the value of the characterization function coefficient in the above formula corresponding to the gas injection amount correction coefficient may be solved, and specifically, a ═ 0.1636, b ═ 1.3036, and c ═ 2.4636. Accordingly, V can be directly utilized_i＝-0.1636×i²-1.3036 xi +2.4636 in place of the above formula, to accomplish the calculation of the correction coefficient of the gas injection amount. In practical applications, the value of the characterization function coefficient may be adjusted based on specific situations, and is not limited to the specific example, which is not described herein again.

S130: calculating a recovery factor based on the correction factor; the recovery factor is used to describe the development effect of the displacement production process.

After the correction factor is calculated, a calculation of the recovery factor may be performed based on the correction factor. The recovery factor represents the proportion of the quantity of the produced crude oil to the quantity of the crude oil stored in the reservoir, and the improvement of the recovery factor can increase the quantity of the crude oil obtained by collection, thereby being beneficial to the effective implementation of the exploitation activity.

For calculating the recovery factor, a recovery factor evaluation model may be constructed in advance, and the correction factor may be introduced into the recovery factor evaluation model to obtain the finally applicable recovery factor. The recovery ratio evaluation model is a corresponding recovery ratio condition obtained by calculation according to various geological parameters.

Specifically, CO is known₂The characterization function of the theoretical model for improving the recovery ratio evaluation in the flooding mode isIn the formula, E_RFor recovery, f; v_kIs a vertical anisotropic coefficient, f; k is permeability, mD; m is fluidity ratio, f; n is the well pattern density, opening/km²；Wherein P is the formation pressure, MPa; p_MMPIs the minimum miscible pressure, MPa; e_PV＝0.3872×(PV)³-1.2521×(PV)²+1.763 × PV +0.0136, where PV is the ratio of the injected volume to the total pore volume, f.

After the correction coefficient is obtained based on the process in step S120, the correction coefficient may be integrated into the characterization function of the theoretical model for oil recovery ratio evaluation, and the adjusted characterization function of the theoretical model for oil recovery ratio evaluation is obtained as

Based on the example description in step S120, a specific formula of the gas injection correction coefficient can be substituted to obtain a complete form of a specific theoretical model function for oil recovery evaluation

Therefore, based on the above-mentioned theoretical model function for oil recovery ratio evaluation, the formula may be used to calculate the oil recovery ratioCalculated recovery ratio of formula (II) E_RFor recovery of oil, V_kIs a vertical anisotropic coefficient, k is permeability, C_iIs a fluidity ratio correction coefficient, M is a fluidity ratio, n is a well pattern density,wherein P is the formation pressure, P_MMPTo minimum miscible pressure, E_PV＝0.3872(V_i×PV)³-1.2521(V_i×PV)²+1.763V_iX PV +0.0136, wherein V_iPV is the ratio of injected volume to total pore volume for gas injection correction factor.

S140: determining an economically optimized well spacing corresponding to the target reservoir based on the recovery factor; the economic optimization well spacing is used for representing the corresponding well spacing when the production yield is maximized.

In practical application, the larger the recovery ratio is, the higher the investment cost for exploitation is, and the pursuit of high recovery ratio can reduce the benefit in the exploitation process, thereby affecting the healthy and sustainable development of the industry. Therefore, based on the obtained recovery ratio, the well spacing in the work area needs to be considered at the same time, and a reasonable well pattern density needs to be set so as to realize the balance of the recovery ratio and the economic benefit.

The economically optimized well spacing may be the well spacing that corresponds when production revenue maximization is considered. Specifically, by combining the design theory of reasonable well pattern density and limit well pattern density, a corresponding model can be established for calculating an economic optimization well spacing calculation model under gas-water alternate flooding.

In particular, can orderAnd solve the above equation. In the formula, NET_v' difference between sales income of produced crude oil in main development period and sum of investment and production cost; p is the selling price of crude oil, ten thousand yuan/t; c is crude oil measure cost, ten thousand yuan/t; n is geological reserve, 10⁴t；E_RFor recovery, f; n is the well pattern density, opening/km²(ii) a M is the total investment of a single well, ten thousand yuan per hole; a is the oil-containing area, km²。

By solving the above equation, the well pattern density n can be calculated, and then the economic optimization well spacing corresponding to the target reservoir is determined according to the well pattern density.

In some embodiments, to define the calculation, an economic limit well spacing may also be calculated. The economic limit well spacing is used to define a minimum value for well spacing taking into account break-even balance.

Specifically, the formula (P-C). times.NxE can be used_RCalculating economic limit well spacing of-MxAxn-GxPV ═ 0Wherein P is the selling price of crude oil, C is the cost of crude oil measure, N is the geological reserve, E_RFor recovery, M is the total investment per well, A is the oil bearing area, n is the well pattern density, G is the displacement gas price, and PV is the ratio of the injection volume to the total pore volume.

After the economic limit well spacing is calculated, the economic limit well spacing can be used for limiting the range of the finally obtained target well spacing so as to adapt to the requirements of actual production development.

In some embodiments, an annual fluid production rate profile may also be obtained. The annual liquid production speed curve is used for representing the change of the liquid production speed with the thickness of the stratum under the corresponding permeability condition.

Specifically, the liquid extraction speed in the liquid extraction speed curve is obtained by the following method: using formulasCalculating the fluid-collecting speed, wherein V_aThe annual fluid production speed under unit pressure difference, k is permeability, L is injection-production well spacing, phi is porosity, mu is crude oil viscosity, r is_wIs the radius of the wellbore, S_oIs the original oil saturation.

It should be noted that the above-mentioned economic optimized well spacing, economic ultimate well spacing and annual fluid production speed curve can respectively calculate the results under different formation permeability conditions, thereby obtaining a plurality of economic optimized well spacing, economic ultimate well spacing or annual fluid production speed curves.

After the economic optimization well spacing is obtained, a well spacing design chart can be constructed based on the economic optimization well spacing, and the well spacing design chart is used for describing the change situation of the economic optimization well spacing under different stratum thicknesses and different permeability. The target well spacing can be determined by combining corresponding geological parameters in practical application in subsequent steps through the well spacing design chart.

Preferably, the well spacing design chart can also comprise economic limit well spacing and annual fluid production speed curves so as to better determine the target well spacing in a subsequent stage.

The well spacing design plate is illustrated with a specific example. Because different gas-water injection ratios and permeability distribution conditions can influence the display effect of the well spacing design plate, the well spacing design plates in different states are introduced respectively.

Fig. 2A, 2B, 2C, and 2D all correspond to different vertical anisotropic coefficients V when WAG is 1:2, i.e., the injected water-to-gas ratio is 1:2_kThe well spacing design plate. Wherein FIG. 2A is at V_kWell spacing design plate under 0 homogeneous formation conditions, FIG. 2B at V_kWell spacing design panel under 0.3 heterogeneous formation conditions, FIG. 2C at V_kWell spacing design panel under 0.5 heterogeneous formation conditions, FIG. 2D at V_kWell spacing design plate under heterogeneous formation conditions of 0.8.

Fig. 3A, 3B, 3C, and 3D all correspond to different vertical anisotropic coefficients V when WAG is 2:1, i.e., the injected water-to-gas ratio is 2:1_kThe well spacing design plate. Wherein FIG. 3A is at V_kWell spacing design plate under 0 homogeneous formation conditions, FIG. 3B at V_kWell spacing design plate under 0.3 heterogeneous formation conditions, FIG. 3C at V_kWell spacing design plate under 0.5 heterogeneous formation conditions, FIG. 3D at V_kWell spacing design plate under heterogeneous formation conditions of 0.8.

Fig. 4A, 4B, 4C, and 4D correspond to different vertical anisotropic coefficients V when WAG is 1:1, i.e., the injected water-to-gas ratio is 1:1_kThe well spacing design plate. Wherein FIG. 4A is at V_kWell spacing design plate under 0 homogeneous formation conditions, fig. 4B at V_kWell spacing design panel under 0.3 heterogeneous formation conditions, FIG. 4C at V_kWell spacing design panel under 0.5 heterogeneous formation conditions, FIG. 4D at V_kWell spacing design plate under heterogeneous formation conditions of 0.8.

The examples corresponding to the above drawings are only for better describing the well spacing design plate in the embodiments of the present specification, and in practical applications, the well spacing design plate may be adjusted according to the requirements of specific applications, and will not be described herein again.

S150: a target well spacing is determined based on the economically optimized well spacing and the reservoir parameters.

After determining the economically optimized well spacing and the reservoir parameters, the reservoir parameters and the economically optimized well spacing may be combined to determine a target well spacing. Specifically, after exploration is performed on the reservoir, parameters such as the thickness of the stratum, the permeability and the vertical heterogeneous coefficient corresponding to the oil reservoir can be determined. And under the condition that different thicknesses, permeabilities and vertical heterogeneous coefficients of different layers correspond to the economic optimization well spacing, different well spacing parameter values correspond to the economic optimization well spacing, so that the corresponding economic optimization well spacing can be obtained by combining the reservoir layer parameters on the basis of the results obtained by calculation according to different parameters.

For example, assuming that the measured thickness of the reservoir at the place 15 meters, the water-gas ratio during displacement is 1:1, the vertical heterogeneous coefficient is 0.5, and the permeability is 2mD, the value of the curve of the economically optimal well spacing corresponding to 2mD at the place 15m may be determined to be 360m by referring to the well spacing design chart corresponding to fig. 4C.

In some embodiments, the target well spacing may also be calculated in conjunction with the annual fluid production rate per unit of pressure difference when determining the target well spacing. Specifically, the initial annual fluid production rate per unit of differential pressure may be determined in a well spacing design plate based on reservoir parameters. Correspondingly, the expected annual fluid production rate per unit pressure difference can also be preset. Based on the obtained formula, using the formulaCalculating a target well spacing, wherein L_{Reasonable and reasonable}At a target well spacing, Δ Q₁Is the initial annual fluid production rate, Δ Q, per unit pressure difference₂Is the expected annual fluid production rate, L, per unit pressure difference_{Optimization of}The well spacing is optimized for economy.

In the process of determining the target well spacing, the economic limit well spacing can be determined based on a well spacing design chart, the obtained target well spacing is limited by the economic limit well spacing, and the target well spacing is ensured not to be smaller than the economic limit well spacing.

Based on the above description of the embodiments, a specific scenario example is used for further explanation. Assuming that the well spacing design plate for the work area a is shown in fig. 5, the formation thickness of the reservoir in the work area is 20m, the permeability is 1mD, and the vertical heterogeneous coefficient is 0.5. During development, the WAG is 1:1 gas-water alternative injection mode for CO₂And (5) driving. The step of determining a target well spacing based on the corresponding well spacing design plate may be as follows.

Step 1: selecting V according to the practical reservoir heterogeneity and gas-water alternative injection proportion of the work area A_kA 0.5 heterogeneous formation pattern (WAG 1:1) "well spacing design pattern.

Step 2: drawing 1 straight line perpendicular to the thickness of the stratum by 20m on a chart, and finding out the intersection point of a curve with the permeability of 1mD and the straight line from economically optimal well spacing relation curves with different permeabilities. And the numerical value of the well spacing corresponding to the intersection point is the economic optimal well spacing of the work area A. Thus, the economically optimal well spacing L for the work area A_{Optimization of}＝360m。

And step 3: and (3) finding out the intersection point of the curve with the permeability of 1mD and the vertical line drawn in the step (2) from the economic ultimate well spacing relation curves with different permeabilities. And the numerical value of the well spacing corresponding to the intersection point is the economic limit well spacing of the work area A. Thus, the economic limit well L of the work area A_{Extreme limit}＝50m。

And 4, step 4: and (3) finding out the intersection point of the curve with the permeability of 1mD and the perpendicular line made in the step (2) from the annual liquid extraction speed relation curves under the unit pressure difference with different permeabilities. The numerical value of the annual liquid extraction speed under the unit pressure difference corresponding to the intersection point is the initial annual liquid extraction speed under the unit pressure difference of the work area A: delta Q₁＝0.015％/(MPa·a)。

And 5: according to the initial annual liquid production speed under the unit pressure difference, the influence of fracturing measures is considered, and the expected annual liquid production speed under the unit pressure difference is given as delta Q₂The reasonable well spacing of the working area A is L calculated by using the formula 10 (0.1%/(MPa · a))_{Reasonable and reasonable}＝140m。

Through the introduction of the above embodiment and the scenario example, it can be seen that, in the method, after the parameters in the displacement generation process are acquired, the displacement production parameters are used to calculate the correction coefficient so as to correct the displacement production process. The correction factor can then be used to calculate the recovery factor to determine the corresponding development effect and to determine an economically optimal well spacing to determine the size of the well spacing to be set when the production yield is maximized. Finally, the actual well spacing is adjusted by combining the related parameters of the reservoir, and the final target well spacing can be obtained. By the method, the well spacing meeting the actual requirement can be determined by combining the geological parameters and the economic benefit in the actual production, so that the economic benefit and the construction difficulty are ensured, the mining efficiency is improved, and important guidance is provided for the oil reservoir development based on gas-water alternative flooding.

Based on the well spacing design method based on gas-water alternating oil displacement, the specification also provides an embodiment of a well spacing design device based on gas-water alternating oil displacement. As shown in fig. 6, the well spacing design device based on gas-water alternating flooding specifically comprises the following modules.

A displacement production parameter acquisition module 610 for acquiring displacement production parameters; the displacement production parameters are used to represent parameters corresponding to a gas flooding process and/or a water flooding process.

A correction coefficient calculation module 620, configured to calculate a correction coefficient using the displacement production parameter; the correction coefficient is used for representing a parameter for correcting the displacement production parameter based on the displacement effect.

A recovery factor evaluation model construction module 630 for calculating a recovery factor based on the correction factor; the recovery factor is used to describe the development effect of the displacement production process.

An economic optimization well spacing determination module 640 for determining an economic optimization well spacing corresponding to the target reservoir based on the recovery factor; the economic optimization well spacing is used for representing the corresponding well spacing when the production yield is maximized.

A target well spacing determination module 650 for determining a target well spacing based on the economically optimized well spacing and the reservoir parameters.

According to the well spacing design method based on gas-water alternating oil displacement, the embodiment of the specification further provides a well spacing design device based on gas-water alternating oil displacement. As shown in FIG. 7, the well spacing design equipment based on gas-water alternating flooding comprises a memory and a processor.

In this embodiment, the memory may be implemented in any suitable manner. For example, the memory may be a read-only memory, a mechanical hard disk, a solid state disk, a U disk, or the like. The memory may be used to store computer program instructions.

In this embodiment, the processor may be implemented in any suitable manner. For example, the processor may take the form of, for example, a microprocessor or processor and a computer-readable medium that stores computer-readable program code (e.g., software or firmware) executable by the (micro) processor, logic gates, switches, an Application Specific Integrated Circuit (ASIC), a programmable logic controller, an embedded microcontroller, and so forth. The processor may execute the computer program instructions to perform the steps of: acquiring displacement production parameters; the displacement production parameter is used for representing a parameter corresponding to a gas flooding process and/or a water flooding process; calculating a correction coefficient by using the displacement production parameter; the correction coefficient is used for representing a parameter for correcting the displacement production parameter based on the displacement effect; calculating a recovery factor based on the correction factor; the recovery factor is used for describing the development effect of the displacement production process; determining an economically optimized well spacing corresponding to the target reservoir based on the recovery factor; the economic optimization well spacing is used for representing the corresponding well spacing when the production yield is maximized; a target well spacing is determined based on the economically optimized well spacing and the reservoir parameters.

The systems, devices, modules or units illustrated in the above embodiments may be implemented by a computer chip or an entity, or by a product with certain functions. One typical implementation device is a computer. In particular, the computer may be, for example, a personal computer, a laptop computer, a cellular telephone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

From the above description of the embodiments, it is clear to those skilled in the art that the present specification can be implemented by software plus a necessary general hardware platform. Based on such understanding, the technical solutions of the present specification may be essentially or partially implemented in the form of software products, which may be stored in a storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and include instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments of the present specification.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

The description is operational with numerous general purpose or special purpose computing system environments or configurations. For example: personal computers, server computers, hand-held or portable devices, tablet-type devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like.

This description may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The specification may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.

While the specification has been described with examples, those skilled in the art will appreciate that there are numerous variations and permutations of the specification that do not depart from the spirit of the specification, and it is intended that the appended claims include such variations and modifications that do not depart from the spirit of the specification.