Method and device for acquiring gas-water gravitational differentiation behavior in oil reservoir considering oil layer dip angle

Abstract

The invention relates to a method and a device for acquiring a gas-water gravitational differentiation behavior in an oil reservoir considering an oil layer dip angle, and relates to the technical field of oil-gas field development. Comprising the following steps: based on a maximum distance criterion of migration of a gas-water mixed displacement area along an inclined displacement direction by a complete gravitational differentiation distance and a vertical water-drive reservoir thickness criterion after complete gas-water differentiation by a complete differentiation thickness or height; according to the water phase flow, the gas phase flow, the flow of the gas-water mixing area, the total flow, the gas flow-total flow of the injected fluid, the water flow-total flow of the injected fluid, the thickness of the oil reservoir, the water vapor and the gas-water differential velocity, a gravitational differential model of the oil reservoir is obtained; and inputting the basic parameters of the target water-gas alternate injection inclined oil reservoir into the oil reservoir gravitational differentiation model for calculation to obtain a gas-water gravitational differentiation behavior result of the target oil reservoir. According to the acquisition method provided by the invention, efficient prediction of the gravitational differentiation behavior of the oil reservoir developed by alternately injecting water and gas is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development, and in particular to a method and device for obtaining the gas-water gravity segregation behavior in a reservoir considering the oil layer dip angle. Background Technique

[0002] Currently, the Water-Alternating-Gas (WAG) technology, as an important method for improving oil recovery, has been gradually widely applied in the development of complex reservoirs. By alternately injecting water and gas (such as CO2, natural gas, nitrogen, associated gas, etc.), it utilizes the expansion displacement of the gas phase, the mobility control of water, and the gas miscibility effect to expand the swept volume and improve the oil displacement efficiency.

[0003] For example, CN119412003A discloses an offshore gas-water alternating injection system, including a water injection pipeline network, a gas injection pipeline network, an injection pipe, and a connection device. The connection device is provided with an injection port, a water injection port, and a gas injection port communicated with the injection port. Among them, the water injection pipeline network is connected to the water injection port, the gas injection pipeline network is connected to the gas injection port, the top end of the injection pipe is connected to the injection port, and the bottom end extends downward to the target formation. The water injection pipeline network can inject water into the target formation through the gas injection port, the injection port, and the injection pipe, and the gas injection pipeline network can inject gas into the target formation through the gas injection port, the injection port, and the injection pipe. Among them, a pressure relief pipeline is also provided on the gas injection pipeline network. After the gas injection stage is completed and before the water injection stage starts, the system pressure can be released through the pressure relief pipeline to reduce the system pressure to the water injection pressure or lower than the water injection pressure, so that the water can be normally injected. [[ID=[]]

[0004] However, in a tilted reservoir, the gravity segregation effect has a significant impact on the distribution and migration of gas and water phases. The application of traditional WAG technology in this field faces many challenges. In traditional WAG flooding technology, the calculation of the gravity segregation effect is mostly based on the assumption of a homogeneous reservoir, ignoring the reservoir dip angle, heterogeneity, and multiphase flow interaction, resulting in the following deficiencies and problems in the existing technologies and methods:

[0005] (1) Model simplification and insufficient parameter coupling lead to large errors: The influence of reservoir dip angle, permeability anisotropy, and fluid viscosity difference on the segregation distance and segregation thickness is not comprehensively considered, and the prediction deviation is significant, making it difficult to accurately characterize the nonlinear segregation behavior in a tilted reservoir;

[0006] (2) High computational complexity and large simplified solution errors: After considering gravity, the nonlinearity of the model is enhanced. The solution process of complex models has a large amount of calculation, especially the parameters and workload required by numerical simulation methods are even greater, which is time-consuming and inefficient, and it is difficult to meet the need for real-time optimization of injection and production strategies. If the nonlinear terms are simplified, the error will increase.

[0007] Therefore, there is an urgent need for a model and calculation method that can accurately quantify the gas-water gravity segregation behavior in tilted reservoirs to solve the prediction deviation problem caused by the simplification of the model and solution in traditional methods, so as to ensure the optimization efficiency and development benefits of the WAG injection and production scheme for tilted reservoirs. Summary of the Invention

[0008] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for obtaining the gas-water gravity segregation behavior in a reservoir considering the oil layer dip angle, so as to solve the problem that the prediction accuracy is reduced due to the simplification of the model and solution in the existing method, and further unable to ensure the optimization efficiency and development benefits of the WAG injection and production scheme for tilted reservoirs.

[0009] To achieve this purpose, the present invention adopts the following technical solutions:

[0010] In the first aspect, the present invention provides a method for obtaining the gas-water gravity segregation behavior in a reservoir considering the oil layer dip angle, and the obtaining method includes:

[0011] Based on the first criterion and the second criterion, according to the water phase flow rate q w relation, the gas phase flow rate q g relation, the gas-water mixed zone flow rate q m relation, the total flow rate q t relation, the gas fraction flow rate f g -total flow rate q t relation, the water fraction flow rate f w -total flow rate q t relation, the reservoir thickness h relation, the water-gas relation and the gas-water segregation velocity v relation, obtain the reservoir gravity segregation model;

[0012] Input the basic parameters of the target water-gas alternating injection into the tilted reservoir into the reservoir gravity segregation model for calculation to obtain the gas-water gravity segregation behavior result of the target reservoir;

[0013] Among them, the first criterion is that the complete gravity segregation distance L g is the maximum distance criterion for the migration of the gas-water mixed displacement zone along the tilted displacement direction; the second criterion is that the complete segregation thickness H wg or the complete segregation height h wg is the vertical water flooding reservoir thickness criterion after the gas-water complete segregation.

[0014] The obtaining method provided by the present invention realizes the efficient prediction of the gas-water gravity segregation behavior in the reservoir developed by water-gas alternating injection on the basis of considering the oil layer dip angle of the reservoir, and solves the problems of low calculation accuracy, long time consumption and low efficiency in the current situation of considering the oil layer dip angle.

[0015] As a preferred technical solution of the present invention, the water phase flow rate qw The relationship includes:

[0016]

[0017] In the formula, λ w is the relative mobility of the aqueous phase in the water displacement zone; k is the horizontal permeability of the reservoir, mD; W is the width of the reservoir, m; h w is the vertical water flooding reservoir thickness, m; p is the pressure, Pa; x is the distance from any point on the displacement path to the injection well, m; ρ w is the density of water, g / cm 3 ; g is the acceleration due to gravity, m / s 2 ; α is the reservoir dip angle.

[0018] As a preferred technical solution of the present invention, the gas flow rate q g The relationship includes:

[0019]

[0020] In the formula, λ g is the relative mobility of the gas phase in the gas displacement zone; h g is the vertical gas flooding reservoir thickness, m; ρ g is the density of the gas phase, g / cm 3 .

[0021] As a preferred technical solution of the present invention, the gas-water mixture zone flow rate q m The relationship includes:

[0022]

[0023] In the formula, λ tm is the total relative mobility in the mixed displacement zone; h m is the vertical reservoir thickness in the gas-water mixed displacement zone, m; ρ m is the density in the gas-water mixed displacement zone, g / cm 3 .

[0024] As a preferred technical solution of the present invention, the total flow rate q t The relationship includes:

[0025] q t = q g + q m + q w .

[0026] Preferably, the gas fraction flow rate f g - total flow rate q t The relationship includes:

[0027] f g q t= q g + f g q m 。

[0028] Preferably, the moisture flow rate f of the injected fluid w - total flow rate q t The relationship includes:

[0029] f w q t = q w + f w q m 。

[0030] Preferably, the relationship of the reservoir thickness h includes:

[0031] h = h g + h m + h w 。

[0032] Preferably, the water-gas relationship includes:

[0033] (q w + q g )f w f g = vWx.

[0034] Preferably, the relationship of the gas-water differentiation velocity v includes:<{}

[0035] v = Δρgk v λ wm λ gm / λ tm cosα

[0036] In the formula, Δρ is the density difference between water and gas phase, g / cm 3 ; k v is the vertical permeability of the reservoir, mD; λ wm is the relative water phase mobility in the mixed displacement zone; λ gm is the relative gas phase mobility in the mixed displacement zone.

[0037] As a preferred technical solution of the present invention, the reservoir gravity differentiation model includes:

[0038]

[0039] In the formula, β2 = 2 - G2M gw h - 2M gw WGR; M gw is the gas-water mobility ratio; is the injected water-gas ratio.

[0040] Preferably, the basic parameters include: reservoir dip angle α, reservoir horizontal permeability k, reservoir vertical permeability k v , reservoir width W, reservoir thickness h, total flow rate q t , injection water-gas ratio WGR, water-gas relative permeability curve, water-phase relative mobility λ in the water displacement zone w , water-phase relative mobility λ in the mixed displacement zone wm , gas-phase relative mobility λ in the mixed displacement zone gm , total relative mobility λ in the mixed displacement zone tm , density of water ρ w , density of gas phase ρ g and density difference Δρ between water and gas phase.

[0041] As a preferred technical solution of the present invention, in the calculation, if the distance x of any point on the displacement path from the injection well is less than the complete gravity segregation distance L g , then the vertical water displacement reservoir thickness h w and vertical gas displacement reservoir thickness h g on any point of the displacement path are solved by using the Gaussian elimination method and numerical method. If the distance x of any point on the displacement path from the injection well is greater than or equal to the complete gravity segregation distance L g , then according to the reservoir gravity segregation model, the vertical water displacement reservoir thickness h w at any point on the displacement path is the complete segregation thickness h wg , and the vertical gas displacement reservoir thickness h g is the reservoir thickness h - complete segregation thickness h wg .

[0042] Preferably, the results of the gas-water gravity segregation behavior of the target reservoir include: data results and / or curve results.

[0043] Preferably, the data results include: complete gravity segregation distance L g , complete segregation thickness H wg or complete segregation height h wg , and the vertical water displacement reservoir thickness h w and vertical gas displacement reservoir thickness h g at any point on the displacement path.

[0044] The curve results include: gas-water gravity segregation map.

[0045] In a second aspect, the present invention provides an acquisition device for considering the gas-water gravity segregation behavior in a reservoir with an oil layer dip angle. The acquisition device includes: one of an acquisition module unit, an electronic device or a medium;

[0046] The acquisition module unit includes: a reservoir gravity segregation model acquisition module and / or a reservoir gravity segregation model module, a basic parameter acquisition module, and a calculation module;

[0047] The reservoir gravity segregation model acquisition module is configured to, based on a first criterion and a second criterion, according to the water phase flow rate q w relationship formula, the gas phase flow rate q g relationship formula, the gas-water mixing zone flow rate q m relationship formula, the total flow rate q t relationship formula, the gas fraction flow rate f g - total flow rate q t relationship formula, the water fraction flow rate f w - total flow rate q t relationship formula, the reservoir thickness h relationship formula, the water-gas relationship formula, and the gas-water segregation velocity v relationship formula, to acquire a reservoir gravity segregation model, where the first criterion is that the complete gravity segregation distance L g is the maximum distance criterion for the gas-water mixed displacement zone to migrate along the inclined displacement direction; the second criterion is that the complete segregation thickness H wg or the complete segregation height h wg is the vertical water drive reservoir thickness criterion after complete gas-water segregation;

[0048] The reservoir gravity segregation model module is configured to save the reservoir gravity segregation model;

[0049] The basic parameter acquisition module is configured to acquire the basic parameters of the target water-gas alternating injection inclined reservoir;

[0050] The calculation module is configured to input the basic parameters of the target water-gas alternating injection inclined reservoir into the reservoir gravity segregation model for calculation, to obtain the gas-water gravity segregation behavior result of the target reservoir;

[0051] The electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the acquisition method for considering the gas-water gravity segregation behavior in a reservoir with an oil layer dip angle according to the first aspect;

[0052] The computer-executable instructions are stored in the medium, and when the computer-executable instructions are executed by a processor, the acquisition method for considering the gas-water gravity segregation behavior in a reservoir with an oil layer dip angle according to the first aspect is implemented.

[0053] As a preferred technical solution of the present invention, the reservoir gravity segregation model includes:

[0054]

[0055] In the formula, β2 = 2 - G2M gw h - 2M gw WGR; M gw is the gas - water mobility ratio; is the injected water - gas ratio.

[0056] As a preferred technical solution of the present invention, the basic parameters include: reservoir dip angle α, reservoir horizontal permeability k, reservoir vertical permeability k v , reservoir width W, reservoir thickness h, total flow rate q t , injected water - gas ratio WGR, water - gas relative permeability curve, water - phase relative mobility λ w in the water - displacement area, water - phase relative mobility λ wm in the mixed - displacement area, gas - phase relative mobility λ gm in the mixed - displacement area, total relative mobility λ tm , density of water ρ w , density of gas phase ρ g and density difference Δρ between water and gas phase.

[0057] Preferably, in the calculation module, if the distance x of any point on the displacement path from the injection well is less than the complete gravity segregation distance L g , then the vertical water - displacement reservoir thickness h w and the vertical gas - displacement reservoir thickness h g at any point on the displacement path are solved by using the Gaussian elimination method and numerical method. Otherwise, the vertical water - displacement reservoir thickness h w and the vertical gas - displacement reservoir thickness h g at any point on the displacement path are obtained according to the reservoir gravity segregation model.

[0058] Preferably, the results of the gas - water gravity segregation behavior of the target reservoir include: data results and / or curve results.

[0059] Preferably, the data results include: complete gravity segregation distance, complete segregation thickness H wg or complete segregation height h wg , and the vertical water - displacement reservoir thickness h w and the vertical gas - displacement reservoir thickness h g at any point on the displacement path.

[0060] Preferably, the curve results include: gas - water gravity segregation map.

[0061] Compared with the prior - art solutions, the present invention has the following beneficial effects:

[0062] The present invention proposes a gravity segregation model and calculation method for water alternating gas (WAG) development of reservoirs, which realizes the accurate quantification of the gas-water gravity segregation behavior in inclined reservoirs using the WAG development method, and can obtain the complete gravity segregation distance and the complete segregation thickness or height. It solves the problems of low calculation accuracy, long time consumption, and low efficiency when considering the reservoir dip angle. The new model and calculation method have greatly improved both in predicting accuracy and efficiency in quantitatively depicting the gas-water gravity segregation behavior, providing a solid theoretical support for the real-time injection-production optimization of oilfields developed by WAG. Brief Description of the Drawings

[0063] Figure 1 It is a flowchart of the method for obtaining the gas-water gravity segregation behavior in a reservoir considering the oil layer dip angle provided by an embodiment of the present invention;

[0064] Figure 2 It is a schematic diagram of the physical model of WAG development in an inclined reservoir provided by an embodiment of the present invention;

[0065] Figure 3 It is a schematic diagram of the device for obtaining the gas-water gravity segregation behavior in a reservoir considering the oil layer dip angle provided by an embodiment of the present invention;

[0066] Figure 4 It is a schematic diagram of the electronic device provided by an embodiment of the present invention;

[0067] Figure 5 It is a flowchart of the method for obtaining the gas-water gravity segregation behavior in a reservoir considering the oil layer dip angle provided by Embodiment 1 of the present invention;

[0068] Figure 6 It is the relative permeability curve of water and gas of the oilfield used in Embodiment 1 of the present invention;

[0069] Figure 7 It is the gas-water gravity segregation map of the oilfield obtained in Embodiment 1 of the present invention when using the water alternating gas injection method.

[0070] In the figure: 100 - reservoir gravity segregation model acquisition module, 200 - reservoir gravity segregation model module, 300 - basic parameter acquisition module, 400 - calculation module;

[0071] 10 - electronic device, 11 - processor, 12 - ROM, 13 - RAM, 14 - bus, 15 - I / O interface, 16 - input unit, 17 - output unit, 18 - storage unit, 19 - communication unit.

[0072] The present invention will be further described in detail below. However, the following examples are only simple examples of the present invention and do not represent or limit the scope of the protection of the present invention. The scope of protection of the present invention shall be subject to the claims. Detailed Embodiments

[0073] To better illustrate the present invention and facilitate understanding of its technical solution, typical but non-limiting embodiments of the present invention are as follows:

[0074] This embodiment provides a method for obtaining the gas-water gravity segregation behavior in a reservoir considering the oil layer dip angle, and the process is as Figure 1 shown below:

[0075] Based on the first criterion and the second criterion, according to the water phase flow rate q w relationship, the gas phase flow rate q g relationship, the gas-water mixed zone flow rate q m relationship, the total flow rate q t relationship, the gas fraction flow rate f of the injected fluid g -total flow rate q t relationship, the water fraction flow rate f of the injected fluid w -total flow rate q t relationship, the reservoir thickness h relationship, the water-gas relationship, and the gas-water segregation velocity v relationship, to obtain a reservoir gravity segregation model;

[0076] Input the basic parameters of the target water-gas alternating injection into the inclined reservoir into the reservoir gravity segregation model for calculation to obtain the gas-water gravity segregation behavior result of the target reservoir.

[0077] Among them, the first criterion is that the complete gravity segregation distance L g is the maximum distance criterion for the migration of the gas-water mixed displacement zone along the inclined displacement direction; the second criterion is that the complete segregation thickness H wg or the complete segregation height h wg is the vertical water flooding reservoir thickness criterion after complete gas-water segregation.

[0078] In the present invention, a reservoir considering the oil layer dip angle means that the reservoir is inclined and has a certain inclination angle, such as Figure 2 shown in the figure, where α in the figure is the reservoir dip angle.

[0079] Among them, the water phase flow rate q w relationship includes:

[0080]

[0081] In the formula, λ w is the relative mobility of the water phase in the water displacement zone; k is the horizontal permeability of the reservoir, mD; W is the width of the reservoir, m; h w is the vertical water flooding reservoir thickness, m; p is the pressure, Pa; x is the distance from any point on the displacement path to the injection well, m; ρ w is the density of water, g / cm 3 ; g is the acceleration of gravity, m / s 2 , and α is the reservoir dip angle.

[0082] Among them, the gas phase flow rate q g The relationships include:

[0083]

[0084] Where λ g is the relative fluidity of gas phase in the gas displacement zone; h g is the vertical gas drive reservoir thickness, m; ρ g is the density of the gas phase, g / cm 3 .

[0085] Among them, the flow rate q in the gas-water mixing zone is m The relationships include:

[0086]

[0087] Where λ tm is the total relative mobility in the mixed displacement zone; h m is the vertical reservoir thickness in the gas-water mixed displacement zone, m; ρ m is the density of the gas-water mixed displacement zone, g / cm 3 .

[0088] Among them, the total flow q t The relationships include:

[0089] q t =q g +q m +q w ;

[0090] Among them, the gas flow rate f of the injected fluid g -Total flow q t The relationships include:

[0091] f g q t =q g +f g q m ;

[0092] Wherein, the water flow rate f of the injected fluid is w -Total flow q t The relationships include:

[0093] f w q t =q w +f w q m ;

[0094] The relationship between the reservoir thickness h includes:

[0095] h=h g +h m +h w ;

[0096] The water-gas relationship includes:

[0097] (q w +q g )f w f g =vWx;

[0098] The relationship between the gas-water separation rate v includes:

[0099] v=Δρgk v λ wm λ gm / λ tm cosα

[0100] Where Δρ is the density difference between water and gas phase, g / cm 3 ;k v is the vertical permeability of the reservoir, mD; λ wm is the relative fluidity of water phase in the mixed displacement zone; gm is the relative fluidity of the gas phase in the mixed displacement zone.

[0101] By solving the above relationship equations simultaneously, the reservoir gravity differentiation model can be obtained.

[0102] Wherein, the reservoir gravity differentiation model includes:

[0103]

[0104] Where, β2=2-G2M gw h-2M gw WGR; M gw is the gas-water mobility ratio; is the injected water-gas ratio.

[0105] The basic parameters include: reservoir inclination angle α, reservoir horizontal permeability k, reservoir vertical permeability k v , reservoir width W, reservoir thickness h, total flow q t , injected water-gas ratio WGR, water-gas relative permeability curve, water phase relative fluidity λ in the water displacement zone w , relative fluidity of water phase in mixed displacement zone λ wm , gas phase relative fluidity λ in the mixed displacement zone gm , the total relative mobility λ in the mixed displacement zone tm , water density ρ w , gas phase density ρ gand the density difference Δρ between the water and gas phases.

[0106] Among them, in the above calculation, if the distance x from any point on the displacement path to the injection well is less than the complete gravitational segregation distance L g , then the vertical water drive reservoir thickness h w and the vertical gas drive reservoir thickness h g at any point on the displacement path are solved by using the Gaussian elimination method and the numerical method. If the distance x from any point on the displacement path to the injection well is greater than or equal to the complete gravitational segregation distance L g , then the vertical water drive reservoir thickness h w at any point on the displacement path is the complete segregation thickness H wg , and the vertical gas drive reservoir thickness h g is the reservoir thickness h - the complete segregation thickness H wg .

[0107] Among them, the gas-water gravitational segregation behavior results of the target reservoir include: data results and / or curve results.

[0108] Among them, the data results include: the complete gravitational segregation distance L g , the complete segregation thickness H wg or the complete segregation height h wg , and the vertical water drive reservoir thickness h w and the vertical gas drive reservoir thickness h g at any point on the displacement path.

[0109] In the present invention, the specific combinations of the data results include: the complete gravitational segregation distance L g , the complete segregation thickness H wg , and the vertical water drive reservoir thickness h w and the vertical gas drive reservoir thickness h g at any point on the displacement path; or, the complete gravitational segregation distance L g , the complete segregation height h wg , and the vertical water drive reservoir thickness h w and the vertical gas drive reservoir thickness h g at any point on the displacement path.

[0110] The curve results include: the gas-water gravitational segregation map.

[0111] In the present invention, the gas-water gravitational segregation map of the gas-water gravitational segregation behavior results of the target reservoir is drawn based on the relevant data in the data results.

[0112] Furthermore, this embodiment provides an acquisition device for the gas-water gravitational segregation behavior in a reservoir considering the oil layer dip angle. The acquisition device includes: one of an acquisition module unit, an electronic device, or a medium.

[0113] The acquisition module unit includes: a reservoir gravity segregation model acquisition module and / or a reservoir gravity segregation model module, a basic parameter acquisition module, and a calculation module, as Figure 3 shown.

[0114] The reservoir gravity segregation model acquisition module is used to obtain a reservoir gravity segregation model based on a first criterion and a second criterion, according to the water-phase flow rate q w relationship, the gas-phase flow rate q g relationship, the gas-water mixed zone flow rate q m relationship, the total flow rate q t relationship, the gas fraction flow rate f g -total flow rate q t relationship, the water fraction flow rate f w -total flow rate q t relationship, the reservoir thickness h relationship, the water-gas relationship, and the gas-water segregation velocity v relationship, where the first criterion is the complete gravity segregation distance L g is the maximum distance criterion for the gas-water mixed displacement zone to migrate along the inclined displacement direction; the second criterion is the complete segregation thickness H wg or the complete segregation height h wg is the vertical water drive reservoir thickness criterion after complete gas-water segregation;

[0115] The reservoir gravity segregation model module is used to save the reservoir gravity segregation model;

[0116] The basic parameter acquisition module is used to obtain the basic parameters of the target water-gas alternating injection inclined reservoir;

[0117] The calculation module is used to input the basic parameters of the target water-gas alternating injection inclined reservoir into the reservoir gravity segregation model for calculation, and obtain the gas-water gravity segregation behavior result of the target reservoir.

[0118] Among them, the reservoir gravity segregation model in the reservoir gravity segregation model acquisition module or the reservoir gravity segregation model module includes:

[0119]

[0120] In the formula, β2 = 2 - G2M gw h - 2M gw WGR; M gw is the gas-water mobility ratio; is the injected water-gas ratio.

[0121] Among them, the basic parameters to be obtained by the basic parameter acquisition module include: reservoir dip angle α, reservoir horizontal permeability k, reservoir vertical permeability k v , reservoir width W, reservoir thickness h, total flow rate q t , injection water-gas ratio WGR, water-gas relative permeability curve, water phase relative mobility λ in the water displacement zone w , water phase relative mobility λ in the miscible displacement zone wm , gas phase relative mobility λ in the miscible displacement zone gm , total relative mobility λ in the miscible displacement zone tm , density of water ρ w , density of gas phase ρ g and density difference Δρ between water and gas phase;

[0122] Among them, in the above calculation, if the distance x from any point on the displacement path to the injection well is < complete gravity segregation distance L g , then the vertical water displacement reservoir thickness h w and vertical gas displacement reservoir thickness h g on any point of the displacement path are solved by using Gaussian elimination method and numerical method. If the distance x from any point on the displacement path to the injection well is ≥ complete gravity segregation distance L g , then according to the reservoir gravity segregation model, the vertical water displacement reservoir thickness h w on any point of the displacement path is the complete segregation thickness h wg , and the vertical gas displacement reservoir thickness h g is the reservoir thickness h - complete segregation thickness h wg .

[0123] Among them, the results of gas-water gravity segregation behavior of the target reservoir shown in the calculation module include: data results and / or curve results; data results include: complete gravity segregation distance L g , complete segregation thickness H wg or complete segregation height h wg , and the vertical water displacement reservoir thickness h w and vertical gas displacement reservoir thickness h g on any point of the displacement path; curve results include: gas-water gravity segregation map.

[0124] Regarding the device in the above embodiment, the specific manners in which each module performs operations have been described in detail in the embodiment related to the method, and will not be elaborated here.

[0125] Further, this embodiment provides an electronic device, which is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are only examples and are not intended to limit the implementation of the invention described and / or claimed herein.

[0126] As Figure 4 shown, the electronic device 10 includes at least one processor 11, and a memory communicatively connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc. The memory stores a computer program executable by the at least one processor. The processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. The I / O interface 15 is also connected to the bus 14.

[0127] Multiple components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a magnetic disk, an optical disc, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0128] The processor 11 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the acquisition method for considering the gas-water gravity segregation behavior in the oil reservoir with the oil layer dip angle described above.

[0129] In some embodiments, the above-described method for obtaining the gas-water gravity segregation behavior in a reservoir considering the oil layer dip can be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the above-described method for obtaining the gas-water gravity segregation behavior in a reservoir considering the oil layer dip can be performed. Alternatively, in other embodiments, the processor 11 can be configured to perform the above-described method for obtaining the gas-water gravity segregation behavior in a reservoir considering the oil layer dip by any other suitable means (e.g., by means of firmware).

[0130] Various embodiments of the systems and techniques described above in this document can be implemented in digital electronic circuitry, integrated circuit systems, field-programmable gate arrays (FPGA), application specific integrated circuits (ASIC), application specific standard products (ASSP), systems-on-chip (SOC), complex programmable logic devices (CPLD), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special-purpose or general-purpose programmable processor that receives data and instructions from a storage system, at least one input device, and at least one output device, and transmits the data and instructions to the storage system, the at least one input device, and the at least one output device.

[0131] The computer programs for implementing the methods of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, such that the computer programs, when executed by the processor, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The computer programs can be executed entirely on the machine, partially on the machine, as a stand-alone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0132] In the context of the present invention, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, the computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0133] In order to provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0134] The systems and techniques described herein can be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer having a graphical user interface or a web browser through which the user can interact with an implementation of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: local area network (LAN), wide area network (WAN), blockchain network, and the Internet.

[0135] A computing system may include a client and a server. The client and the server are generally far from each other and usually interact via a communication network. The relationship between the client and the server is generated by computer programs running on corresponding computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or a cloud host, which is a host product in the cloud computing service system, and solves the defects of difficult management and weak business scalability existing in traditional physical hosts and VPS services.

[0136] The server provided in this embodiment includes: a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the foregoing method for obtaining the gas-water gravity segregation behavior in a reservoir considering the oil layer dip angle.

[0137] Unless otherwise specifically stated, terms such as processing, computing, calculating, determining, displaying, etc. can refer to the actions and / or processes of one or more processing or computing systems, or similar devices, which operate on and transform data represented as physical (such as electronic) quantities in the registers or memories of the processing system into other data similarly represented as physical quantities in the memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals can be represented using any of a variety of different technologies and methods. For example, the data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0138] Those skilled in the art should also understand that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments of the present invention can be implemented as electronic hardware, computer software, or a combination thereof. To clearly illustrate the interchangeability between hardware and software, the above various illustrative components, blocks, modules, circuits, and steps have been generally described in terms of their functions. Whether such functions are implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system. Skilled technicians can implement the described functions in a flexible manner for each specific application, but such implementation decisions should not be construed as departing from the protection scope of the present invention.

[0139] The steps of the methods or algorithms described in the embodiments of the present invention may be directly embodied as hardware, software modules executed by a processor, or a combination thereof. The software modules may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium well-known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium may also be a component of the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and the storage medium may also exist as discrete components in the user terminal.

[0140] For software implementation, the technologies described in the present invention may be implemented by modules (e.g., procedures, functions, etc.) that execute the functions described in this application. These software codes may be stored in a memory unit and executed by a processor. The memory unit may be implemented inside the processor or outside the processor. In the latter case, it is communicatively coupled to the processor by various means, which are well-known in the art.

[0141] Further, in order to clarify the present invention, actual examples are used for illustration, as follows:

[0142] Embodiment 1

[0143] This embodiment provides a calculation method for gas-water gravity segregation behavior in a reservoir considering the oil layer dip angle. The calculation process is as Figure 5 shown, as follows:

[0144] Select a reservoir developed by water and gas alternating injection, and collect and determine the basic parameters, including respectively representing the oil layer dip angle α, the horizontal permeability k of the reservoir, the vertical permeability k v of the reservoir, the width W of the reservoir, the thickness h of the reservoir, the total flow rate q t of the reservoir, the gas-water relative permeability curve, the water phase relative mobility λ in the water flooding area w of the reservoir, the water phase relative mobility λ in the mixed flooding area wm of the reservoir, the gas phase relative mobility λ in the mixed flooding area gm of the reservoir, the total relative mobility λ in the mixed flooding area tm of the reservoir, the density ρ of water w of the reservoir, the density ρ of the gas phase g of the reservoir, the water flow rate of the injected fluid, i.e., the water cut f w of the reservoir, the gas flow rate of the injected fluid, i.e., the gas content f g of the reservoir, and the acceleration of gravity g.

[0145] Taking a channel-type deepwater turbidite sandstone reservoir developed by overseas water alternating gas injection as an example, the reservoir dip angle α is 2°, and the development method is to inject WAG in the downdip direction and produce oil in the updip direction. The injection-production well spacing is 1000m, the reservoir thickness h is 25m, the reservoir (channel) width W is 1000m, the horizontal permeability k of the reservoir is 1000mD, and the vertical permeability k v is 50mD. The injection fluid velocity, i.e., the total flow rate q t is 6360m 3 / d (underground). The underground density of the injected water is 990kg / m 3 , and the underground density of the injected gas is 300kg / m 3 . The underground viscosity of the injected water is 0.5mPa·s, and the underground viscosity of the injected gas is 0.04mPa·s. The water-gas relative permeability curve is shown in Appendix Figure 6 . Calculate the different water-gas injection ratios WGR (including 0.2, 0.5, 1, 2) respectively.

[0146] From the water-gas injection ratio WGR, the injection water cut f w =WGR / (1 + WGR) can be calculated, which are 0.17, 0.33, 0.50, and 0.67 respectively.

[0147] Using the water-gas relative permeability curve and the fractional flow equation, the water saturation S w at different water cuts f w is obtained by back-calculation, which are 0.6815, 0.74, 0.7804, and 0.8168 respectively.

[0148] Furthermore, the relative water phase mobility λ wm in the mixed displacement zone is obtained, which are 214.93, 305.74, 382.39, and 462.20 respectively; the relative gas phase mobility λ gm in the mixed displacement zone is obtained, which are 214.94, 305.74, 382.40, and 462.20 respectively.

[0149] Substituting the above parameters into the formula of the reservoir gravity segregation model, L g can be calculated, which are 355.8m, 468.59m, 541.62m, and 580.39m respectively; h wg is 22.25m. Further solving for h w at any position, h g , and drawing the curves of water and gas in different zones along the injection-production process, as shown in Figure 7 .

[0150] In summary, the present invention realizes the accurate quantification of the gas-water gravity segregation behavior in a tilted reservoir using the WAG development method, and can obtain the complete gravity segregation distance and the complete segregation thickness or height. The new model and calculation method have greatly improved both the prediction accuracy and efficiency in quantitatively characterizing the gas-water gravity segregation behavior, providing a solid theoretical support for the real-time injection-production optimization of oilfields using WAG.

[0151] It is declared that the present invention uses the above embodiments to illustrate the detailed structural features of the present invention, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of the components selected by the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

[0152] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0153] In addition, it should be noted that, in the case of no contradiction, the various specific technical features described in the above specific embodiments can be combined in any suitable manner. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0154] In addition, any combination can be made between various different embodiments of the present invention, as long as it does not violate the idea of the present invention, it should also be regarded as the content disclosed by the present invention.

Claims

1. A method for obtaining the gas-water gravity segregation behavior in a reservoir considering the dip angle of the oil layer, characterized in that, The acquisition method includes: Based on the first criterion and the second criterion, according to the aqueous phase flow rate q w relation, the gas phase flow rate q g relation, the gas-liquid mixing zone flow rate q m relation, the total flow rate q t relation, the gas fraction flow rate f of the injected fluid g - the total flow rate q t relation, the water fraction flow rate f of the injected fluid w - the total flow rate q t relation, the reservoir thickness h relation, the water-gas relation and the gas-liquid differentiation velocity v relation, obtain the reservoir gravity differentiation model; Inputting the basic parameters of the target water-alternating-gas injection into an inclined reservoir into a reservoir gravity segregation model for calculation to obtain the gas-water gravity segregation behavior result of the target reservoir; Among them, the first criterion is the complete gravity differentiation distance L g which is the maximum distance criterion for the migration of the gas-water mixed displacement zone along the inclined displacement direction; the second criterion is the complete differentiation thickness H wg or the complete differentiation height h wg which is the vertical water drive reservoir thickness criterion after the complete differentiation of gas and water.

2. The acquisition method according to claim 1, wherein The aqueous phase flow rate q w The relationship includes: where λ w is the relative mobility of the aqueous phase in the water displacement zone; k is the horizontal permeability of the reservoir, mD; W is the width of the reservoir, m; h w is the vertical water drive reservoir thickness, m; p is the pressure, Pa; x is the distance from any point on the displacement path to the injection well, m; ρ w is the density of water, g / cm 3 ; g is the acceleration due to gravity, m / s 2 ; α is the reservoir dip angle.

3. The acquisition method according to claim 1 or 2, characterized in that, The gas flow rate q g The relationship includes: where λ g is the relative gas mobility in the gas displacement zone; h g is the vertical gas reservoir thickness, m; ρ g is the density of the gas phase, g / cm 3 .

4. The acquisition method according to any one of claims 1 to 3, characterized in that, The flow rate q of the air-water mixing zone m The relational expression includes: where λ tm is the total relative mobility in the mixed displacement zone; h m is the vertical reservoir thickness in the gas-water mixed displacement zone, m; ρ m is the density in the gas-water mixed displacement zone, g / cm 3 .

5. The acquisition method according to any one of claims 1-4, characterized in that The total flow rate q t The relationship includes: q t = q g + q m + q w ; Preferably, the gas flow rate f of the injected fluid g - total flow rate q t The relationship includes: f g q t = q g + f g q m ; Preferably, the moisture flow rate f of the injected fluid w - total flow rate q t The relationship includes: f w q t = q w + f w q m ; Preferably, the relational expression of the reservoir thickness h includes: h = h g + h m + h w ; Preferably, the relational expression of the water and gas includes: (q w +q g )f w f g = vWx; Preferably, the relational expression of the gas-water segregation velocity v includes: v = Δρgk v λ wm λ gm / λ tm cosα where Δρ is the density difference between water and gas phase, g / cm 3 ; k v is the vertical permeability of the reservoir, mD; λ wm is the relative mobility of the aqueous phase in the mixed displacement zone; λ gm is the relative mobility of the gas phase in the mixed displacement zone.

6. The acquisition method according to claims 1-5, characterized in that, The reservoir gravity segregation model includes: In the formula, β2 = 2 - G2M gw h - 2M gw WGB; M gw is the gas-water mobility ratio; is the injected water-gas ratio. Preferably, the basic parameters include: reservoir dip angle α, reservoir horizontal permeability k, reservoir vertical permeability k v , reservoir width W, reservoir thickness h, total flow rate q t , injection water-gas ratio WGR, water-gas relative permeability curve, water phase relative mobility λ in the water displacement zone w , water phase relative mobility λ in the mixed displacement zone wm , gas phase relative mobility λ in the mixed displacement zone gm , total relative mobility λ in the mixed displacement zone tm , density ρ of water w , density ρ of the gas phase g and density difference Δρ between water and the gas phase.

7. The acquisition method according to claims 1-6, characterized in that In the calculation, if the distance x from any point on the displacement path to the injection well < L (the complete gravity segregation distance), g then the vertical water drive reservoir thickness h w and the vertical gas drive reservoir thickness h g are solved using the Gaussian elimination method and the numerical method. If the distance x from any point on the displacement path to the injection well ≥ L (the complete gravity segregation distance), g then, based on the reservoir gravity segregation model, the vertical water drive reservoir thickness h w at any point on the displacement path is the complete segregation thickness h wg , and the vertical gas drive reservoir thickness h g is the reservoir thickness h - the complete segregation thickness h wg ; Preferably, the gas-water gravity segregation behavior result of the target reservoir includes: data results and / or curve results; Preferably, the data results include: the complete gravity differentiation distance L g , the complete differentiation thickness H wg or the complete differentiation height h wg , and the vertical water drive reservoir thickness h w and the vertical gas drive reservoir thickness h g ; Preferably, the curve results include: gas-water gravity segregation diagrams.

8. An acquisition device for gas-water gravity segregation behavior in a reservoir considering the dip angle of the oil layer, characterized in that, The acquisition device includes: one of an acquisition module unit, an electronic device, or a medium; The acquisition module unit includes: a reservoir gravity segregation model acquisition module and / or a reservoir gravity segregation model module, a basic parameter acquisition module, and a calculation module; The reservoir gravity segregation model acquisition module is used to obtain a reservoir gravity segregation model based on a first criterion and a second criterion, according to the water phase flow rate q w relationship, the gas phase flow rate q g relationship, the gas-water mixed zone flow rate q m relationship, the total flow rate q t relationship, the gas fraction flow rate f of the injected fluid g - the total flow rate q t relationship, the water fraction flow rate f of the injected fluid w - the total flow rate q t relationship, the reservoir thickness h relationship, the water-gas relationship, and the gas-water segregation velocity v relationship, where the first criterion is that the complete gravity segregation distance L g is the maximum distance criterion for the migration of the gas-water mixed displacement zone along the inclined displacement direction; the second criterion is that the complete segregation thickness H wg or the complete segregation height h wg is the vertical water drive reservoir thickness criterion after complete gas-water segregation; The reservoir gravity segregation model module is used to store the reservoir gravity segregation model; The basic parameter acquisition module is used to acquire the basic parameters of the target water-alternating-gas injection into an inclined reservoir; The calculation module is used to input the basic parameters of the target water-alternating-gas injection into an inclined reservoir into the reservoir gravity segregation model for calculation to obtain the gas-water gravity segregation behavior result of the target reservoir; The electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the acquisition method for considering the gas-water gravity segregation behavior in a reservoir with a reservoir dip angle according to any one of claims 1-7; The medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, the acquisition method for considering the gas-water gravity segregation behavior in a reservoir with a reservoir dip angle according to any one of claims 1-7 is implemented.

9. The acquisition device according to claim 8, wherein The reservoir gravity segregation model includes: Wherein, β2 = 2 - G2M gw h - 2M gw WGR; M gw is the gas - water mobility ratio; is the injected water - gas ratio.

10. The acquisition device according to claim 8, characterized in that, The basic parameters include: reservoir dip angle α, reservoir horizontal permeability k, reservoir vertical permeability k v , reservoir width W, reservoir thickness h, total flow rate q t , injection water-gas ratio WGR, water-gas relative permeability curve, water phase relative mobility λ in the water displacement area w , water phase relative mobility λ in the mixed displacement area wm , gas phase relative mobility λ in the mixed displacement area gm , total relative mobility λ in the mixed displacement area tm , density of water ρ w , density of gas phase ρ g and density difference Δρ between water and gas phase; Preferably, if the distance x from any point on the displacement path to the injection well in the calculation module is < the complete gravity segregation distance L g , then the vertical water drive reservoir thickness h w and the vertical gas drive reservoir thickness h g are solved by using the Gaussian elimination method and the numerical method. Otherwise, the vertical water drive reservoir thickness h w and the vertical gas drive reservoir thickness h g on any point of the displacement path are obtained according to the reservoir gravity segregation model; Preferably, the gas-water gravity segregation behavior result of the target reservoir includes: data results and / or curve results; Preferably, the data results include: the complete gravity differentiation distance L g , the complete differentiation thickness H wg or the complete differentiation height h wg , and the vertical water drive reservoir thickness h w and the vertical gas drive reservoir thickness h g ; Preferably, the curve results include: gas-water gravity segregation diagrams.

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