Quantitative evaluation method and electronic equipment for stable displacement conditions of underground river type gas drive well group

Abstract

The present invention discloses a quantitative evaluation method and electronic equipment for stable displacement conditions of a dark river type gas drive well group. The method includes: establishing a gas drive conceptual model of a dark river reservoir based on mine data; obtaining the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir; and obtaining the stable displacement velocity of the gas drive conceptual model based on the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir. The present invention obtains the stable displacement velocity of the gas drive conceptual model through the gas phase equivalent fluidity and oil phase equivalent fluidity of the dark river reservoir. The calculation is simple, fast and accurate. Through the calculation of the equivalent stable displacement velocity of the dark river type well group, a displacement velocity chart of different reservoir development positions of the double-layer dark river is formed, thereby screening out geological conditions that are conducive to stable displacement of gas drive, providing a basis for selecting a gas drive well group, delaying gas channeling, and further providing theoretical support for the implementation of gravity-assisted nitrogen drive technology.

Description

Technical Field

[0001] The invention belongs to the field of gas injection development of fracture-cavity oil reservoirs, and specifically relates to a quantitative evaluation method for stable displacement conditions of a dark river type gas drive well group and electronic equipment. Background Art

[0002] The fracture-cave system is developed in the fracture-cave carbonate reservoir, and the vertical permeability is high. It is difficult to achieve a balanced oil-gas interface similar to the gas drive of sandstone reservoirs. Gas overburden fingering is easy to occur during gas drive, resulting in premature gas channeling in the oil wells, which limits the gas drive development effect of fracture-cave carbonate reservoirs. The ancient underground river system is mainly runoff dissolution. It is a complex system formed by one or more underground karst pipelines in multiple periods. It is formed by the collapse and burial of the karst system and the overlapping and cutting of the underground waterways. It has a variety of forms and complex structures, resulting in large differences in the gas drive effect of the gas drive well group in the ancient underground river system. How to determine the stable displacement rate during the gas injection process in the underground river reservoir is the basis for guiding efficient gas injection development. Through domestic and foreign patent searches and literature surveys, it is found that there are very few studies on the balanced stable displacement of fracture-cave reservoirs, and there is no research on the equivalent stable displacement rate of underground river reservoirs. A fast and effective method for evaluating stable displacement conditions has not yet been established.

[0003] At present, the main methods for stabilizing displacement rate include reservoir engineering method, indoor experimental method and numerical simulation method.

[0004] Reservoir engineering methods are based on Darcy's law of oil and water phases, and the fluid exchange rate in different permeable layers is derived. Wang Gang, Wang Pengfei, and Ao Wenjun (2016) studied the influence of displacement rate on the oil recovery efficiency of different types of oil layers based on seepage mechanics, based on theoretical analysis, in view of the differences in geological conditions and water drive characteristics of different reservoirs. The results show that for heterogeneous oil layers, there is an optimal displacement rate range. If the displacement rate is too low, the oil in the low permeability layer is not conducive to being driven out. If the displacement rate is too high, invalid water circulation will be formed, which will reduce the utilization rate of water injection and cause the water injection development effect to deteriorate. This method is a theoretical analysis and physical simulation experiment of water injection displacement rate, which has not yet been extended to gas injection displacement rate. The reservoir conditions targeted are also sandstone reservoirs, which are not suitable for fracture-cavity reservoirs and underground river reservoirs.

[0005] Indoor physical simulation experiments are based on the principle of similarity to make physical models and conduct displacement experiments with different displacement rates. Song Zhaojie and Yang Liu (2018) designed and produced fracture models with different openings based on the multi-scale nature of fractures in fracture-cavity reservoirs, conducted visualization experiments of water-driven oil in fractures, and analyzed the effects of different displacement rates on oil displacement. The results showed that in the horizontal displacement process, there is an optimal injection rate that makes the water drive sweep effect optimal. However, due to the large differences in the scale of the reservoir body of fracture-cavity reservoirs, although the principle of similarity is followed in the process of physical model making, it is difficult to make a truly similar model. The gas drive experiment is an intelligent qualitative evaluation, and it is impossible to quantitatively obtain the stable displacement rate of gas drive.

[0006] Numerical simulation method, by establishing profile models of different structural types, analyzes the gas drive front conditions in a three-dimensional model. Mi Honggang, Lei Xiao, et al. (2004) used a combination of long core gas injection gravity stable drive with an inclination angle, a two-dimensional homogeneous profile model of the injection and production well group with an inclination angle, a layered profile model, and a rhythmic profile model, and adopted the method of numerical simulation of the gas injection drive mechanism. The simulation results show that for horizontal displacement, the core length of about 2m is the best, while for the case of inclination and vertical, the longer the core length, the better the gravity stable displacement effect, and a relatively stable downward gas-oil interface can be formed. The accuracy of this method depends on the richness of the data and the depth of understanding of the simulation personnel. There are problems such as the need for a lot of data, long simulation time, and expensive simulation software. It cannot meet the needs of the mine to quickly determine the stable displacement speed to guide the gas injection design.

[0007] Therefore, there is a particular need for a method that can accurately and quickly evaluate the stable displacement conditions of the dark river reservoir in the fracture-vuggy oil reservoir and screen the geological conditions that are conducive to achieving stable displacement. Summary of the invention

[0008] The purpose of the present invention is to provide a calculation method for quickly and accurately evaluating the stable displacement speed of a gas drive well group in a dark river type fracture-cave oil reservoir and further determining the stable displacement conditions.

[0009] The present invention provides a method for quantitatively evaluating stable displacement conditions of a dark river type gas drive well group, comprising: establishing a gas drive conceptual model of a dark river reservoir based on mine data; obtaining the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir; and obtaining the stable displacement velocity of the gas drive conceptual model based on the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir.

[0010] Optionally, the gas drive conceptual model of the underground river reservoir includes a first underground river reservoir, a second underground river reservoir and a third underground river reservoir, wherein the depths of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir are successively increased, and obtaining the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the underground river reservoir includes: establishing the gas phase flow rate and oil phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, respectively; according to the flow continuity principle, based on the expression of the gas phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, obtaining The gas phase outflow pressure of a dark river reservoir is obtained based on the expression of the oil phase flow rate of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir; the gas phase flow rate of the gas drive conceptual model of the dark river reservoir is obtained based on the gas phase outflow pressure of the first dark river reservoir; the oil phase flow rate of the gas drive conceptual model of the dark river reservoir is obtained based on the oil phase outflow pressure of the first dark river reservoir; the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir are obtained based on the gas phase flow rate and oil phase flow rate of the gas drive conceptual model of the dark river reservoir, respectively.

[0011] Optionally, the expressions for the gas phase flow rates of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir are:

[0012]

[0013]

[0014]

[0015] The expressions of the oil phase flow rates of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir are:

[0016]

[0017]

[0018]

[0019] Among them, u 1g is the gas phase velocity of the first underground river reservoir, λ 1g is the gas phase mobility of the first dark river reservoir, P1 is the injection pressure of the injection well, P1' is the gas phase outflow pressure of the first dark river reservoir, p1" is the oil phase outflow pressure of the first dark river reservoir, h1 is the thickness of the first dark river reservoir, u 2g is the gas phase velocity of the second underground river reservoir, λ 2gis the gas phase mobility of the second dark river reservoir, P2' is the outflow pressure of the second dark river reservoir, h2 is the thickness of the second dark river reservoir, P2 is the outflow pressure of the production well, u 3g is the gas phase velocity of the third underground river reservoir, λ 3g is the gas phase mobility of the third dark river reservoir, h3 is the thickness of the third dark river reservoir; u 1o is the oil phase flow rate of the first underground river reservoir, λ 1o is the oil phase mobility of the first underground river reservoir, u 2o is the oil phase flow rate of the second dark river reservoir, λ 2o is the oil phase mobility of the second dark river reservoir, u 3o is the oil phase flow rate of the third dark river reservoir, λ 3o is the oil phase mobility of the third dark river reservoir, and h3 is the thickness of the third dark river reservoir.

[0020] Optionally, the gas phase outflow pressure of the first underground river reservoir is obtained based on the expression of the gas phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, and the oil phase outflow pressure of the first underground river reservoir is obtained based on the expression of the oil phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, including: according to the principle of flow continuity, based on the expression of the gas phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, a group of gas phase equations are obtained: the gas phase outflow pressure of the first underground river reservoir is obtained by solving the group of gas phase equations; according to the principle of flow continuity, based on the expression of the oil phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, a group of oil phase equations are obtained: the oil phase outflow pressure of the first underground river reservoir is obtained by solving the group of oil phase equations.

[0021] Optionally, the gas outflow pressure of the first dark river reservoir is obtained by the following formula:

[0022]

[0023] The oil outflow pressure of the first dark river reservoir is obtained by the following formula:

[0024]

[0025] Among them, p1' is the gas phase outflow pressure of the first underground river reservoir, p1" is the oil phase outflow pressure of the first underground river reservoir, A1 is the flow cross-sectional area of ​​the first underground river reservoir, A2 is the flow cross-sectional area of ​​the second underground river reservoir, and A3 is the flow cross-sectional area of ​​the third underground river reservoir.

[0026] Optionally, the gas phase flow rate of the gas drive conceptual model of the dark river reservoir is:

[0027]

[0028] The oil phase flow rate of the gas drive conceptual model of the dark river reservoir is:

[0029]

[0030] Among them, q g is the gas phase flow rate of the gas drive conceptual model of the underground river reservoir, q o It is the oil phase flow rate of the gas drive conceptual model of the dark river reservoir.

[0031] Optionally, the gas phase equivalent mobility of the gas drive conceptual model of the dark river reservoir is obtained by the following formula:

[0032]

[0033] The oil phase equivalent mobility of the gas drive conceptual model of the dark river reservoir is obtained by the following formula:

[0034]

[0035] Among them, A Z is the equivalent cross-sectional area of ​​the gas drive conceptual model of the underground river reservoir, and H is the vertical thickness from the original oil and gas interface to the bottom of the production well, that is, the height difference of the production layer.

[0036] Optionally, obtaining the stable displacement velocity of the gas drive conceptual model based on the gas phase equivalent fluidity and the oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir comprises: obtaining the initial displacement velocity of the gas drive conceptual model based on the gas phase equivalent fluidity and the oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir according to the principle of statics;

[0037] A boundary condition is added to the initial displacement velocity of the gas drive conceptual model to obtain a stable displacement velocity of the gas drive conceptual model.

[0038] Optionally, the stable displacement rate of the gas drive conceptual model is obtained by the following formula:

[0039]

[0040] Among them, u c is the stable displacement velocity of the gas drive conceptual model, h og is the original oil-gas interface depth, Δρ is the density difference between the gas phase and the oil phase, and g is the gravitational acceleration.

[0041] The present invention also provides an electronic device, comprising: a memory storing executable instructions; a processor, the processor running the executable instructions in the memory to implement the above-mentioned quantitative evaluation method for stable displacement conditions of the dark river type gas drive well group.

[0042] The beneficial effects of the present invention are as follows: the quantitative evaluation method for stable displacement conditions of underground river type gas drive well groups of the present invention obtains the stable displacement velocity of the gas drive conceptual model through the gas phase equivalent fluidity and oil phase equivalent fluidity of the underground river reservoir body. The calculation is simple, fast and accurate. Through the calculation of the equivalent stable displacement velocity of the underground river type well group, a displacement velocity chart of different reservoir development positions of the double-layer underground river is formed, thereby screening out geological conditions that are conducive to stable gas drive displacement, providing a basis for selecting gas drive well groups, delaying gas channeling, and further providing theoretical support for the implementation of gravity-assisted nitrogen drive technology.

[0043] The present invention has other features and advantages, which will be apparent from or will be described in detail in the accompanying drawings and the following specific embodiments incorporated herein, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0045] Figure 1 A flow chart of a method for quantitatively evaluating stable displacement conditions of a dark river type gas drive well group according to an embodiment of the present invention is shown.

[0046] Figure 2 It is a typical double-layer underground river karst system.

[0047] Figure 3 A single underground river gas drive conceptual model of a method for quantitatively evaluating stable displacement conditions of an underground river type gas drive well group according to an embodiment of the present invention is shown.

[0048] Figure 4 A schematic diagram of the formation of a dark river gas cone is shown in a method for quantitatively evaluating stable displacement conditions of a dark river type gas drive well group according to an embodiment of the present invention.

[0049] Figure 5 The deep distribution pattern of the river reservoir of a method for quantitatively evaluating the stable displacement conditions of a dark river type gas drive well group according to an embodiment of the present invention is shown.

[0050] Figure 6 The shallow distribution pattern of the river reservoir of a method for quantitatively evaluating the stable displacement conditions of a dark river type gas drive well group according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0051] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0052] The present invention provides a method for quantitatively evaluating stable displacement conditions of a dark river type gas drive well group, comprising: establishing a gas drive conceptual model of a dark river reservoir based on mine data; obtaining the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir; and obtaining the stable displacement velocity of the gas drive conceptual model based on the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir.

[0053] Specifically, we collected static and dynamic data of the mine, determined the displacement speed of injected gas in production wells, and determined the target blocks for the method application. According to the mine data, we established a gas drive conceptual model for the dark river reservoir. We obtained the gas phase equivalent mobility and oil phase equivalent mobility of the gas drive conceptual model for the dark river reservoir, and further obtained the stable displacement speed of the gas drive conceptual model based on the gas phase equivalent mobility and oil phase equivalent mobility.

[0054] Static data of the mine include: oil phase viscosity, gas phase viscosity, underground density of injected gas, underground density of crude oil, thickness of original oil-gas interface, thickness of deep underground river reservoir, thickness of shallow underground river reservoir, and vertical sweep height of gas phase;

[0055] Mine dynamic data include: injection-production pressure difference, gas phase fluidity, and oil phase fluidity.

[0056] According to an exemplary implementation, a quantitative evaluation method for stable displacement conditions of a dark river type gas drive well group obtains the stable displacement velocity of a gas drive conceptual model through the gas phase equivalent fluidity and oil phase equivalent fluidity of the dark river reservoir. The calculation is simple, fast and accurate. By calculating the equivalent stable displacement velocity of a dark river type well group, a map of displacement velocities at different development positions of double-layer dark river reservoirs is formed, thereby screening out geological conditions that are conducive to stable gas drive, providing a basis for selecting a gas drive well group, delaying gas channeling, and further providing theoretical support for the implementation of gravity-assisted nitrogen drive technology.

[0057] As an optional scheme, the gas drive conceptual model of the underground river reservoir includes the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, wherein the depths of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir increase successively, and obtaining the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the underground river reservoir includes: establishing the gas phase flow rate and oil phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir respectively; according to the flow continuity principle, based on the expression of the gas phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, obtaining the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the underground river reservoir The gas phase outflow pressure of the underground river reservoir is obtained based on the expression of the oil phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir. The gas phase flow rate of the gas drive conceptual model of the underground river reservoir is obtained based on the gas phase outflow pressure of the first underground river reservoir. The oil phase flow rate of the gas drive conceptual model of the underground river reservoir is obtained based on the oil phase outflow pressure of the first underground river reservoir. The gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the underground river reservoir are obtained based on the gas phase flow rate and oil phase flow rate of the gas drive conceptual model of the underground river reservoir, respectively.

[0058] Specifically, according to the depth, the gas drive conceptual model of the underground river reservoir includes the first underground river reservoir, the second underground river reservoir and the third underground river reservoir with increasing depths. The gas phase outflow pressure is obtained by the gas phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, and the gas phase flow rate is obtained according to the gas phase outflow pressure. According to the expression of the gas phase flow rate, the gas phase equivalent fluidity is obtained by solving; the oil phase outflow pressure is obtained by the oil phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, and the oil phase flow rate is obtained according to the oil phase outflow pressure. According to the expression of the oil phase flow rate, the oil phase equivalent fluidity is obtained by solving.

[0059] As an optional solution, the expressions for the gas phase flow rates of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir are:

[0060]

[0061]

[0062]

[0063] The expressions of oil phase flow rate of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir are:

[0064]

[0065]

[0066]

[0067] Among them, u 1g is the gas phase velocity of the first underground river reservoir, λ 1g is the gas phase mobility of the first dark river reservoir, P1 is the injection pressure of the injection well, P1' is the gas phase outflow pressure of the first dark river reservoir, p1" is the oil phase outflow pressure of the first dark river reservoir, h1 is the thickness of the first dark river reservoir, u 2g is the gas phase velocity of the second underground river reservoir, λ 2g is the gas phase mobility of the second dark river reservoir, P2' is the outflow pressure of the second dark river reservoir, h2 is the thickness of the second dark river reservoir, P2 is the outflow pressure of the production well, u 3g is the gas phase velocity of the third underground river reservoir, λ 3g is the gas phase mobility of the third dark river reservoir, h3 is the thickness of the third dark river reservoir; u 1o is the oil phase flow rate of the first underground river reservoir, λ 1o is the oil phase mobility of the first underground river reservoir, u 2o is the oil phase flow rate of the second dark river reservoir, λ 2o is the oil phase mobility of the second dark river reservoir, u 3o is the oil phase flow rate of the third dark river reservoir, λ 3o is the oil phase mobility of the third dark river reservoir, and h3 is the thickness of the third dark river reservoir.

[0068] Specifically, from the motion equation of seepage flow, we know that:

[0069] The gas phase velocity in the shallow underground river reservoir 1 is

[0070]

[0071] In the formula, u 1g ——gas phase velocity in reservoir body 1;

[0072] K1——reservoir 1 permeability;

[0073] μ g ——Nitrogen viscosity;

[0074] λ 1g ——Gas phase mobility in reservoir body 1;

[0075] h1——thickness of reservoir body 1;

[0076] P1 - injection pressure of injection well;

[0077] P1'——gas outflow pressure in reservoir 1;

[0078] Integrating formula (1) yields:

[0079]

[0080] After sorting:

[0081]

[0082] Similarly, the gas phase flow rate in reservoir 2 and reservoir 3 can be expressed as

[0083]

[0084]

[0085] Similarly, the oil phase flow rate in reservoir 1, reservoir 2 and reservoir 3 can be expressed as

[0086]

[0087]

[0088]

[0089] As an optional scheme, based on the expression of the gas phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, the gas phase outflow pressure of the first underground river reservoir is obtained, and based on the expression of the oil phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, the oil phase outflow pressure of the first underground river reservoir is obtained, including: according to the principle of flow continuity, based on the expression of the gas phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, a group of gas phase equations are obtained: the group of gas phase equations are solved to obtain the gas phase outflow pressure of the first underground river reservoir; according to the principle of flow continuity, based on the expression of the oil phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, a group of oil phase equations are obtained: the group of oil phase equations are solved to obtain the oil phase outflow pressure of the first underground river reservoir.

[0090] Specifically, by combining equations (3), (4), and (5), based on the flow continuity principle, the gas phase equation group is obtained:

[0091]

[0092]

[0093] Based on the flow continuity principle, the oil phase equation group is obtained:

[0094]

[0095]

[0096] As an optional solution, the gas outflow pressure of the first dark river reservoir is obtained by the following formula:

[0097]

[0098] The oil outflow pressure of the first dark river reservoir is obtained by the following formula:

[0099]

[0100] Among them, p1' is the gas phase outflow pressure of the first underground river reservoir, p1" is the oil phase outflow pressure of the first underground river reservoir, A1 is the flow cross-sectional area of ​​the first underground river reservoir, A2 is the flow cross-sectional area of ​​the second underground river reservoir, and A3 is the flow cross-sectional area of ​​the third underground river reservoir.

[0101] Specifically, the gas phase outflow pressure in the reservoir 1 is solved based on the gas phase equation group:

[0102]

[0103] The oil phase outflow pressure in reservoir 1 is solved based on the oil phase equation group:

[0104]

[0105] As an alternative, the gas flow rate of the conceptual model of gas drive of the dark river reservoir is:

[0106]

[0107] The oil phase flow rate of the gas drive conceptual model of the dark river reservoir is:

[0108]

[0109] Among them, q g is the gas phase flow rate of the gas drive conceptual model of the dark river reservoir, q o This is the oil phase flow rate of the conceptual model of gas drive in the dark river reservoir.

[0110] Specifically, based on the continuity equation, the gas phase flow rate can be expressed as:

[0111]

[0112] The oil phase flow rate can be expressed as:

[0113]

[0114] As an alternative, the gas phase equivalent mobility of the gas drive conceptual model of the dark river reservoir is obtained by the following formula:

[0115]

[0116] The oil phase equivalent mobility of the gas drive conceptual model of the dark river reservoir is obtained by the following formula:

[0117]

[0118] Among them, A Z is the equivalent cross-sectional area of ​​the gas drive conceptual model of the dark river reservoir, and H is the vertical thickness from the original oil and gas interface to the bottom of the production well, that is, the height difference of the production layer.

[0119] Specifically, according to the continuity equation, formula (9) is changed to solve λ using p1' Zg ,Right now

[0120]

[0121] Substitute the expression of p1', that is, formula (8), into the above formula and express λ as the known quantity Zg ,

[0122]

[0123] Similarly, use p1" to solve λ Zo ,

[0124]

[0125] Substitute the expression of p1" into the above formula and express λ as the known quantity Zo

[0126]

[0127] in, definition

[0128] ξ——plane equivalent coefficient of gas drive sweep range.

[0129] As an optional scheme, based on the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir, obtaining the stable displacement velocity of the gas drive conceptual model includes: according to the principle of statics, based on the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir, obtaining the initial displacement velocity of the gas drive conceptual model; adding boundary conditions to the initial displacement velocity of the gas drive conceptual model to obtain the stable displacement velocity of the gas drive conceptual model.

[0130] Specifically, stable displacement refers to a state in which the oil-gas interface is stable when the oil-phase displacement rate and the gas-phase displacement rate are equal.

[0131] Gas displacement speed:

[0132]

[0133]

[0134] Among them, u zg is the gas phase velocity of the gas flooding conceptual model of the underground river reservoir, λ zg is the gas phase equivalent mobility of the gas drive conceptual model of the underground river reservoir, u zo is the oil phase velocity of the gas flooding conceptual model of dark river reservoirs, λ zo It is the oil phase equivalent mobility of the gas drive conceptual model of dark river reservoir.

[0135] Select two points AB on the conceptual model of gas drive of dark river reservoir, the pressure of oil and gas front interface is equal, and the pressure of points AB is equal. Ignoring the difference of capillary force, according to the principle of statics, we have p A =p B ,Right now:

[0136] p zo -ρ zo gz1=p zg -ρ zo gz2-ρ zg g(z1-z2) (14)

[0137] After sorting, the oil and gas pressure difference is:

[0138] p zo -p zg =ρ zo gz1-ρ zo gz2-ρ zg g(z1-z2)=ΔρgΔz (15)

[0139] When u zg =u zo When the displacement is stable:

[0140]

[0141]

[0142] Further solve to obtain the initial displacement velocity:

[0143]

[0144] Among them, h og ——Depth of original oil and gas interface.

[0145] As an alternative, the stable displacement rate of the gas drive conceptual model is obtained by the following formula:

[0146]

[0147] Among them, u c is the stable displacement velocity of the gas drive conceptual model, h ogis the original oil-gas interface depth, Δρ is the density difference between the gas phase and the oil phase, and g is the gravitational acceleration.

[0148] Specifically, the boundary conditions are solved at the initial displacement velocity to obtain the stable displacement velocity of the equivalent model:

[0149]

[0150] The present invention also provides an electronic device, which includes: a memory storing executable instructions; a processor running the executable instructions in the memory to implement the above-mentioned quantitative evaluation method for stable displacement conditions of the underground river type gas drive well group.

[0151] Embodiment 1

[0152] Figure 1 A flow chart of a method for quantitatively evaluating stable displacement conditions of a dark river type gas drive well group according to an embodiment of the present invention is shown. Figure 2 It is a typical double-layer underground river karst system. Figure 3 A single underground river gas drive conceptual model of a method for quantitatively evaluating stable displacement conditions of an underground river type gas drive well group according to an embodiment of the present invention is shown. Figure 4 A schematic diagram of the formation of a dark river gas cone is shown in a method for quantitatively evaluating stable displacement conditions of a dark river type gas drive well group according to an embodiment of the present invention. Figure 5 The deep distribution pattern of the river reservoir of a method for quantitatively evaluating the stable displacement conditions of a dark river type gas drive well group according to an embodiment of the present invention is shown. Figure 6 The shallow distribution pattern of the river reservoir of a method for quantitatively evaluating the stable displacement conditions of a dark river type gas drive well group according to an embodiment of the present invention is shown.

[0153] Combination Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown in the figure, the quantitative evaluation method for the stable displacement conditions of the dark river type gas drive well group includes:

[0154] Step 1: Based on the mine data, establish a gas drive conceptual model for the dark river reservoir;

[0155] Step 2: Obtain the gas phase equivalent mobility and oil phase equivalent mobility of the gas drive conceptual model of the dark river reservoir;

[0156] The gas drive conceptual model of the underground river reservoir includes the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, wherein the depths of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir increase successively, and obtaining the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the underground river reservoir includes: establishing the gas phase flow rate and oil phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir respectively; according to the flow continuity principle, based on the expression of the gas phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, obtaining the gas phase equivalent fluidity of the first underground river reservoir The gas phase outflow pressure of the reservoir is obtained based on the expression of the oil phase flow rate of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir to obtain the oil phase outflow pressure of the first dark river reservoir; the gas phase flow rate of the gas drive conceptual model of the dark river reservoir is obtained based on the gas phase outflow pressure of the first dark river reservoir; the oil phase flow rate of the gas drive conceptual model of the dark river reservoir is obtained based on the oil phase outflow pressure of the first dark river reservoir; the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir are obtained based on the gas phase flow rate and oil phase flow rate of the gas drive conceptual model of the dark river reservoir, respectively.

[0157] Among them, the expressions of gas phase flow rate of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir are:

[0158]

[0159]

[0160]

[0161] The expressions of oil phase flow rate of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir are:

[0162]

[0163]

[0164]

[0165] Among them, u 1g is the gas phase velocity of the first underground river reservoir, λ 1g is the gas phase mobility of the first dark river reservoir, P1 is the injection pressure of the injection well, P1' is the gas phase outflow pressure of the first dark river reservoir, p1" is the oil phase outflow pressure of the first dark river reservoir, h1 is the thickness of the first dark river reservoir, u 2g is the gas phase velocity of the second underground river reservoir, λ 2g is the gas phase mobility of the second dark river reservoir, P2' is the outflow pressure of the second dark river reservoir, h2 is the thickness of the second dark river reservoir, P2 is the outflow pressure of the production well, u3g is the gas phase velocity of the third underground river reservoir, λ 3g is the gas phase mobility of the third dark river reservoir, h3 is the thickness of the third dark river reservoir; u 1o is the oil phase flow rate of the first underground river reservoir, λ 1o is the oil phase mobility of the first underground river reservoir, u 2o is the oil phase flow rate of the second dark river reservoir, λ 2o is the oil phase mobility of the second dark river reservoir, u 3o is the oil phase flow rate of the third dark river reservoir, λ 3o is the oil phase mobility of the third dark river reservoir, and h3 is the thickness of the third dark river reservoir.

[0166] Among them, based on the expression of the gas phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, the gas phase outflow pressure of the first underground river reservoir is obtained, and based on the expression of the oil phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, the oil phase outflow pressure of the first underground river reservoir is obtained, which includes: according to the principle of flow continuity, based on the expression of the gas phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, a group of gas phase equations are obtained: the group of gas phase equations are solved to obtain the gas phase outflow pressure of the first underground river reservoir; according to the principle of flow continuity, based on the expression of the oil phase flow rate of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir, a group of oil phase equations are obtained: the group of oil phase equations are solved to obtain the oil phase outflow pressure of the first underground river reservoir.

[0167] The gas outflow pressure of the first underground river reservoir is obtained by the following formula:

[0168]

[0169] The oil outflow pressure of the first dark river reservoir is obtained by the following formula:

[0170]

[0171] Among them, p1' is the gas phase outflow pressure of the first underground river reservoir, p1" is the oil phase outflow pressure of the first underground river reservoir, A1 is the flow cross-sectional area of ​​the first underground river reservoir, A2 is the flow cross-sectional area of ​​the second underground river reservoir, and A3 is the flow cross-sectional area of ​​the third underground river reservoir.

[0172] Among them, the gas phase flow rate of the gas drive conceptual model of the dark river reservoir is:

[0173]

[0174] The oil phase flow rate of the gas drive conceptual model of the dark river reservoir is:

[0175]

[0176] Among them, q g is the gas phase flow rate of the gas drive conceptual model of the dark river reservoir, q o This is the oil phase flow rate of the conceptual model of gas drive in the dark river reservoir.

[0177] Among them, the gas phase equivalent mobility of the gas drive conceptual model of the dark river reservoir is obtained by the following formula:

[0178]

[0179] The oil phase equivalent mobility of the gas drive conceptual model of the dark river reservoir is obtained by the following formula:

[0180]

[0181] Among them, A Z is the equivalent cross-sectional area of ​​the gas drive conceptual model of the dark river reservoir, and H is the vertical thickness from the original oil and gas interface to the bottom of the production well, that is, the height difference of the production layer.

[0182] Step 3: Based on the gas phase equivalent mobility and oil phase equivalent mobility of the gas drive conceptual model of the dark river reservoir, the stable displacement velocity of the gas drive conceptual model is obtained.

[0183] Among them, based on the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir, the stable displacement velocity of the gas drive conceptual model is obtained, which includes: according to the principle of statics, based on the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir, the initial displacement velocity of the gas drive conceptual model is obtained; adding boundary conditions to the initial displacement velocity of the gas drive conceptual model to obtain the stable displacement velocity of the gas drive conceptual model.

[0184] Among them, the stable displacement rate of the gas drive conceptual model is obtained by the following formula:

[0185]

[0186] Among them, u c is the stable displacement velocity of the gas drive conceptual model, h og is the original oil-gas interface depth, Δρ is the density difference between the gas phase and the oil phase, and g is the gravitational acceleration.

[0187] like Figure 2 As shown in Figure 1, the gas drive conceptual model is based on the typical double-layer underground river karst system carefully depicted in geology, from which a single underground river is extracted to establish a gas injection conceptual model, as shown in Figure 1. Figure 3 As shown. Figure 4 Ignoring the difference in capillary force, according to the principle of statics, we have p A =p B .

[0188] Taking the underground river reservoir in Tahe Oilfield as an example, the stable displacement velocity is solved.

[0189] (1) Based on the mine data of the underground river reservoir in Tahe Oilfield, as shown in Table 1.

[0190] Table 1 Example 1 Mine Data

[0191]

[0192]

[0193] A conceptual model of underground river reservoirs was established, and the deep distribution of river reservoirs was analyzed based on the collected mine data, such as Figure 5 As shown, the injection well P1 injects nitrogen, and the production well is P2.

[0194] Based on the geological data of the mine, the gas drive plane equivalent coefficient ξ is 5. According to formulas (10) and (11), the oil phase equivalent mobility and gas phase equivalent mobility are calculated respectively, and the distance hog from the original oil and gas interface to the bottom of the production well is 3m. According to formula (19), the stable displacement rate of nitrogen in the deep layer of the river reservoir is calculated to be 0.22m / d.

[0195] (2) Based on the mine data of the underground river reservoir in Tahe Oilfield, as shown in Table 2.

[0196] Table 2 Example 2 Mine Data

[0197]

[0198]

[0199] The conceptual model of the underground river reservoir was established, and the shallow distribution type of the river reservoir was analyzed based on the collected mine data, such as Figure 6 As shown, the injection well P1 injects nitrogen, and the production well is P2.

[0200] Based on the geological data of the mine, the gas drive plane equivalent coefficient ξ is 5. According to formulas (10) and (11), the oil phase equivalent mobility and gas phase equivalent mobility are calculated respectively, and the distance hog from the original oil and gas interface to the bottom of the production well is 3m. According to formula (19), the stable displacement rate of nitrogen in the shallow layer of the river reservoir is calculated to be 0.05m / d.

[0201] It can be seen from the calculation results of the above two embodiments that the underground river type well group has a long river channel, a deep vertical reservoir, and a high nitrogen stable displacement speed, which is conducive to stable gas drive.

[0202] Embodiment 2

[0203] The present disclosure provides an electronic device, which includes: a memory storing executable instructions; a processor running the executable instructions in the memory to implement the above-mentioned method for quantitatively evaluating stable displacement conditions of a dark river type gas drive well group.

[0204] An electronic device according to an embodiment of the present disclosure includes a memory and a processor.

[0205] The memory is used to store non-temporary computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.

[0206] The processor may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In one embodiment of the present disclosure, the processor is used to run the computer-readable instructions stored in the memory.

[0207] Those skilled in the art should be able to understand that in order to solve the technical problem of how to obtain a good user experience, the present embodiment may also include well-known structures such as a communication bus and an interface, and these well-known structures should also be included in the protection scope of the present disclosure.

[0208] For detailed description of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0209] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A quantitative evaluation method for stable displacement conditions of underground river type gas drive well group, characterized in that: include: Based on the mine data, a conceptual model of gas drive of dark river reservoirs was established; Obtaining the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir; Based on the gas phase equivalent mobility and oil phase equivalent mobility of the gas drive conceptual model of the dark river reservoir, a stable displacement velocity of the gas drive conceptual model is obtained; The gas drive conceptual model of the underground river reservoir includes a first underground river reservoir, a second underground river reservoir and a third underground river reservoir, wherein the depths of the first underground river reservoir, the second underground river reservoir and the third underground river reservoir increase in sequence, and the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the underground river reservoir are obtained, including: Establishing expressions for gas phase flow rate and oil phase flow rate of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir respectively; According to the flow continuity principle, based on the expression of the gas phase flow rate of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir, the gas phase outflow pressure of the first dark river reservoir is obtained; based on the expression of the oil phase flow rate of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir, the oil phase outflow pressure of the first dark river reservoir is obtained; Based on the gas phase outflow pressure of the first dark river reservoir, the gas phase flow rate of the gas drive conceptual model of the dark river reservoir is obtained; based on the oil phase outflow pressure of the first dark river reservoir, the oil phase flow rate of the gas drive conceptual model of the dark river reservoir is obtained; Based on the gas phase flow rate and oil phase flow rate of the gas drive conceptual model of the dark river reservoir, respectively, the gas phase equivalent fluidity and the oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir are obtained; Wherein, based on the gas phase equivalent fluidity and oil phase equivalent fluidity of the gas drive conceptual model of the dark river reservoir, obtaining the stable displacement rate of the gas drive conceptual model includes: According to the principle of statics, based on the gas phase equivalent mobility and oil phase equivalent mobility of the gas drive conceptual model of the dark river reservoir, the initial displacement velocity of the gas drive conceptual model is obtained; Adding boundary conditions to the initial displacement velocity of the gas drive conceptual model to obtain a stable displacement velocity of the gas drive conceptual model; The stable displacement rate of the gas drive conceptual model is obtained by the following formula: Among them, u c is the stable displacement velocity of the gas drive conceptual model, h og is the original oil-gas interface depth, Δρ is the density difference between the gas phase and the oil phase, and g is the gravitational acceleration; Among them, the gas phase equivalent mobility of the gas drive conceptual model of the dark river reservoir is obtained by the following formula: The oil phase equivalent mobility of the gas drive conceptual model of the dark river reservoir is obtained by the following formula: Among them, A Z is the equivalent cross-sectional area of ​​the gas drive conceptual model of the underground river reservoir, H is the vertical thickness from the original oil-gas interface to the bottom of the production well, that is, the height difference of the production layer, P1 is the injection pressure of the injection well, P2 is the outflow pressure of the production well, and q g is the gas phase flow rate of the gas drive conceptual model of the underground river reservoir, q o It is the oil phase flow rate of the gas drive conceptual model of the dark river reservoir.

2. The method for quantitatively evaluating stable displacement conditions of a dark river type gas drive well group according to claim 1, characterized in that: The expressions of the gas phase flow rates of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir are: The expressions of the oil phase flow rates of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir are: Among them, u 1g is the gas phase velocity of the first underground river reservoir, λ 1g is the gas phase mobility of the first dark river reservoir, P1' is the gas phase outflow pressure of the first dark river reservoir, p1" is the oil phase outflow pressure of the first dark river reservoir, h1 is the thickness of the first dark river reservoir, u 2g is the gas phase velocity of the second underground river reservoir, λ 2g is the gas phase mobility of the second dark river reservoir, P2' is the outflow pressure of the second dark river reservoir, h2 is the thickness of the second dark river reservoir, u 3g is the gas phase velocity of the third underground river reservoir, λ 3g is the gas phase mobility of the third dark river reservoir, h3 is the thickness of the third dark river reservoir; u 1o is the oil phase flow rate of the first underground river reservoir, λ 1o is the oil phase mobility of the first underground river reservoir, u 2o is the oil phase flow rate of the second dark river reservoir, λ 2o is the oil phase mobility of the second dark river reservoir, u 3o is the oil phase flow rate of the third dark river reservoir, λ 3o is the oil phase mobility of the third dark river reservoir, and h3 is the thickness of the third dark river reservoir.

3. The method for quantitatively evaluating stable displacement conditions of a dark river type gas drive well group according to claim 2, characterized in that: The expression of the gas phase flow rate of the first dark river reservoir, the second dark river reservoir, and the third dark river reservoir is used to obtain the gas phase outflow pressure of the first dark river reservoir; the expression of the oil phase flow rate of the first dark river reservoir, the second dark river reservoir, and the third dark river reservoir is used to obtain the oil phase outflow pressure of the first dark river reservoir, including: According to the flow continuity principle, based on the expressions of the gas phase flow rates of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir, the gas phase equation group is obtained: Solving the gas phase equation group to obtain the gas phase outflow pressure of the first dark river reservoir; According to the flow continuity principle, based on the expressions of the oil phase flow rates of the first dark river reservoir, the second dark river reservoir and the third dark river reservoir, the oil phase equation group is obtained: The oil phase equation group is solved to obtain the oil phase outflow pressure of the first underground river reservoir.

4. The quantitative evaluation method for stable displacement conditions of a dark river type gas drive well group according to claim 3 is characterized in that: The gas outflow pressure of the first dark river reservoir is obtained by the following formula: The oil outflow pressure of the first dark river reservoir is obtained by the following formula: Among them, p1' is the gas phase outflow pressure of the first underground river reservoir, p1" is the oil phase outflow pressure of the first underground river reservoir, A1 is the flow cross-sectional area of ​​the first underground river reservoir, A2 is the flow cross-sectional area of ​​the second underground river reservoir, and A3 is the flow cross-sectional area of ​​the third underground river reservoir.

5. The method for quantitatively evaluating stable displacement conditions of a dark river type gas drive well group according to claim 4, characterized in that: The gas phase flow rate of the gas drive conceptual model of the dark river reservoir is: The oil phase flow rate of the gas drive conceptual model of the dark river reservoir is:

6. An electronic device, characterized in that: The electronic device comprises: A memory storing executable instructions; A processor, wherein the processor runs the executable instructions in the memory to implement the quantitative evaluation method for stable displacement conditions of a dark river type gas drive well group as described in any one of claims 1-5.

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