Method and device for determining gas production quantity of water-producing gas well of water-invaded gas reservoir type gas storage

Abstract

The invention discloses a method and device for determining the gas production quantity of a water-producing gas well of a water-invaded gas reservoir type gas storage.The method comprises the steps that an injection-production zone is divided into a plurality of zones, and the gas saturation and the water saturation of each zone are obtained; calculating the relative permeability of the gas phase of each zone according to the relation between the gas phase relative permeability and the water saturation of gas reservoir gas-water standardized relative permeability curve regression; determining a binomial productivity equation of each zone under different formation pressures; determining an inflow dynamic curve according to a binomial productivity equation; determining an outflow dynamic curve according to the wellhead pressure and the well bore structure parameters; and according to the inflow dynamic curve, the outflow dynamic curve and preset constraint conditions, the gas production rates of the water-producing gas well under different formation pressures are determined. According to the method, the gas production quantity of the water-producing gas well can be determined, and the capacity-reaching and yield-reaching rate of multi-cycle injection-production operation of the water-invaded gas reservoir type gas storage is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of natural gas underground storage, and particularly relates to a method and device for determining gas production capacity of a water-intruded gas reservoir type gas storage well. BACKGROUND

[0002] This section is intended to provide background information to facilitate a better understanding of embodiments of the present application described in the claims. The description herein does not constitute admission of prior art.

[0003] The injection-production capacity is a key index in the design and construction operation stage of the gas storage. At present, the node analysis method is mostly used in the calculation of the injection-production capacity of the gas storage. However, for the gas storage reformed from the water-intruded gas reservoir, the influence of water intrusion on the production capacity of the gas well in different zones is different in the high-intensity injection-production process. If the influence of water production on the gas production capacity of the gas well is not considered in the design stage of the gas storage, the injection-production well number is designed to be low, the gas production capacity is not reasonably distributed, and even the multi-cycle operation of the gas storage is low in the capacity and production rate. SUMMARY

[0004] The embodiments of the present application provide a method for determining the gas production capacity of a water-intruded gas reservoir type gas storage well, which is used to determine the gas production capacity of the water-intruded gas well, so as to reasonably design the injection-production operation index of the gas storage and improve the capacity and production rate of the multi-cycle operation of the gas storage. The method comprises the following steps:

[0005] The injection-production zones are divided into multiple zones. The gas saturation and water saturation of each zone are obtained in the multi-cycle injection-production process of the water-intruded gas reservoir type gas storage.

[0006] The gas-water relative permeability curves of multiple cores in the water-intruded gas reservoir type gas storage are obtained. The gas-water relative permeability curves of each core are standardized to obtain the gas-water standardized relative permeability curve of the gas reservoir.

[0007] The regression relationship between the relative permeability of the gas phase and the water saturation is determined according to the gas-water standardized relative permeability curve of the gas reservoir.

[0008] The relative permeability of the gas phase of each zone is calculated according to the regression relationship between the relative permeability of the gas phase and the water saturation and the water saturation of each zone.

[0009] The binomial productivity equation of each zone under different formation pressures is determined according to the relative permeability of the gas phase of each zone and the different formation pressures.

[0010] The inflow dynamic curve from the formation to the bottom of the well is determined according to the binomial productivity equation with the bottom of the well as the node. The outflow dynamic curve from the bottom of the well to the wellhead is determined according to the wellhead pressure and the well structure parameters. The inflow dynamic curve and the outflow dynamic curve represent the relationship curve between the gas production capacity and the bottom hole pressure.

[0011] The gas production rate of the water-invasion gas reservoir type gas storage water production well is determined according to the inflow dynamic curve, the outflow dynamic curve and the preset constraint condition under different formation pressures.

[0012] The embodiment of the present application also provides a device for determining the gas production rate of the water-invasion gas reservoir type gas storage water production well, which is used to determine the gas production rate of the water production well, so as to reasonably design the injection-production operation index of the gas storage and improve the capacity and production rate of the multi-cycle operation of the gas storage.

[0013] The gas saturation and water saturation obtaining module is used to divide the injection-production zone into multiple zones and obtain the gas saturation and water saturation of each zone in the multi-cycle injection-production process of the water-invasion gas reservoir type gas storage.

[0014] The gas-water relative permeability curve obtaining module is used to obtain the gas-water relative permeability curve of the core in the water-invasion gas reservoir type gas storage, and the gas-water relative permeability curve of the core is standardized to obtain the gas-water standardized relative permeability curve of the gas reservoir.

[0015] The regression relationship determining module is used to determine the regression relationship between the relative permeability of the gas phase and the water saturation according to the gas-water standardized relative permeability curve of the gas reservoir.

[0016] The relative permeability of the gas phase calculating module is used to calculate the relative permeability of the gas phase of each zone according to the regression relationship between the relative permeability of the gas phase and the water saturation and the water saturation of each zone.

[0017] The binomial productivity equation determining module is used to determine the binomial productivity equation of each zone under different formation pressures according to the relative permeability of the gas phase of each zone and different formation pressures.

[0018] The inflow dynamic curve determining module is used to determine the inflow dynamic curve from the formation to the bottom hole according to the binomial productivity equation with the bottom hole as a node; the outflow dynamic curve determining module is used to determine the outflow dynamic curve from the bottom hole to the wellhead according to the wellhead pressure and the well structure parameters; the inflow dynamic curve and the outflow dynamic curve represent the relationship curve between the gas production rate and the bottom hole pressure.

[0019] The gas production rate determining module is used to determine the gas production rate of the water-invasion gas reservoir type gas storage water production well under different formation pressures according to the inflow dynamic curve, the outflow dynamic curve and the preset constraint condition.

[0020] The embodiment of the present application also provides a computer device, which comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, and the processor implements the above-mentioned method for determining the gas production rate of the water-invasion gas reservoir type gas storage water production well when executing the computer program.

[0021] The embodiment of the present application also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the method for determining the gas production of a water-intruded gas reservoir type gas storage water production well.

[0022] The embodiment of the present application also provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to realize the method for determining the gas production of a water-intruded gas reservoir type gas storage water production well.

[0023] In the embodiment of the present application, the injection-production zone is divided into multiple zones, the gas saturation and the water saturation of each zone are obtained in the multi-cycle injection-production process of the water-intruded gas reservoir type gas storage, the gas-water relative permeability curves of multiple cores in the water-intruded gas reservoir type gas storage are obtained, the gas-water relative permeability curves of each core are standardized to obtain the gas-water standardized relative permeability curve of the gas reservoir, the regression relationship between the relative permeability of the gas phase and the water saturation is determined according to the gas-water standardized relative permeability curve of the gas reservoir, the relative permeability of the gas phase of each zone is calculated according to the regression relationship between the relative permeability of the gas phase and the water saturation and the water saturation of each zone, the binomial productivity equation of each zone under different formation pressures is determined according to the relative permeability of the gas phase of each zone and the different formation pressures, the inflow performance curve from the formation to the bottom hole is determined according to the binomial productivity equation with the bottom hole as a node, the outflow performance curve from the bottom hole to the wellhead is determined according to the wellhead pressure and the well structure parameters, the inflow performance curve and the outflow performance curve represent the relationship curve between the gas production and the bottom hole pressure, and the gas production of the water production well is determined according to the inflow performance curve, the outflow performance curve and the preset constraint condition. In the above process, the embodiment of the present application considers the influence of water intrusion on the gas production of different zones in the multi-cycle injection-production process of the water-intruded gas reservoir type gas storage, the gas production of the water production well under different formation pressures is determined through the inflow performance curve, the outflow performance curve and the preset constraint condition, so that the injection-production operation index of the gas storage is reasonably designed, and the capacity and production rate of the multi-cycle operation of the water-intruded gas reservoir type gas storage are improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings. In the drawings:

[0025] Figure 1 It is a flow chart of the method for determining the gas production of a water-intruded gas reservoir type gas storage water production well in the embodiment of the present application.

[0026] Figure 2 Figure of gas-water relative permeability curve of core in the embodiment of the present application;

[0027] Figure 3 Figure of gas-water normalized relative permeability curve of gas reservoir in the embodiment of the present application;

[0028] Figure 4 Figure of gas production analysis under different formation pressures in the embodiment of the present application;

[0029] Figure 5 Figure of the device for determining gas production of water-producing gas well of water-intruded gas reservoir type gas storage in the embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiment of the present application more clear and explicit, the embodiment of the present application is further described in detail below in combination with the drawings. Herein, the schematic embodiment of the present application and the description thereof are used to explain the present application, but not as a limitation to the present application.

[0031] Figure 1 Figure of the method for determining gas production of water-producing gas well of water-intruded gas reservoir type gas storage in the embodiment of the present application, the method comprising:

[0032] Step 101, divide the injection-production zone into multiple zones, and obtain the gas saturation and water saturation of each zone in the multi-cycle injection-production process of the water-intruded gas reservoir type gas storage;

[0033] Step 102, obtain the gas-water relative permeability curve of multiple cores in the water-intruded gas reservoir type gas storage, and perform normalized processing on the gas-water relative permeability curve of each core to obtain the gas-water normalized relative permeability curve of the gas reservoir;

[0034] Step 103, determine the regression relationship between the relative permeability of gas phase and the water saturation according to the gas-water normalized relative permeability curve of the gas reservoir;

[0035] Step 104, calculate the relative permeability of gas phase of each zone according to the regression relationship between the relative permeability of gas phase and the water saturation, and the water saturation of each zone;

[0036] Step 105, determine the binomial productivity equation of each zone under different formation pressures according to the relative permeability of gas phase of each zone and the different formation pressures;

[0037] Step 106, taking the well bottom as a node, determining the inflow performance curve from the formation to the well bottom according to the binomial productivity equation; determining the outflow performance curve from the well bottom to the well head according to the well head pressure and the well structure parameters; the inflow performance curve and the outflow performance curve represent the relationship curve between the gas production and the well bottom pressure;

[0038] Step 107, determining the gas production of the water-producing gas well under different formation pressures according to the inflow performance curve, the outflow performance curve, and in combination with the preset constraint condition.

[0039] The following will specifically explain each step.

[0040] In step 101, the injection-production zone is divided into multiple zones, and the gas saturation and the water saturation of each zone are obtained respectively in the multi-cycle injection-production process of the water-intruded gas reservoir type gas storage.

[0041] In the embodiment, in the multi-cycle injection-production process of the water-intruded gas reservoir type gas storage, the water intrusion has different influences on the gas production of the water-producing gas well in different zones (including the pre-storage pure gas zone, the gas-drive pure gas zone, and the gas-water transition zone). After the zone division, the gas saturation and the water saturation that tend to be stable after multiple cycles in the three zones are obtained through the core seepage experiment.

[0042] In the embodiment, the core is first pretreated, and the pretreatment process is as follows:

[0043] S1: The core is first dried and weighed, saturated with water, and then weighed again to calculate the mass of water and the pore volume.

[0044] S2: A high-pressure pump (with a minimum pressure of about 10 MPa) is used to inject water into the core until the water volume driven out of the outlet end of the core reaches 20 times the pore volume. At this time, it is considered that the core is completely saturated with water, and the pressure at both ends of the core holder, the gas flow rate in the pump, and the displacement time are recorded.

[0045] S3: Another displacement pump is used to inject gas into the core to drive water, and the displacement pressure is basically the same as the inlet end pressure recorded in the previous step. Until the bound water state, that is, the outlet end flow of the core is less than 0.1 ml / h, the pressure at both ends of the core holder, the flow rate of the pump, and the displacement time are recorded.

[0046] Then, on the basis of the above pretreatment, the simulation experiment process of the pre-storage pure gas zone, the gas-drive pure gas zone, and the gas-water transition zone is as follows:

[0047] a. Multi-cycle injection-production process of the pre-storage pure gas zone

[0048] On the basis of S3, first inject gas into the core by using a high-pressure pump to simulate the gas injection process, stop when the inlet pressure of the core reaches the designed upper limit pressure, record the displacement flow rate, displacement time, and the pressure at both ends of the core, then start pressure balance after stopping injection, record the pressure at both ends of the core after balance.

[0049] b. Multi-cycle injection-production operation process of gas-drive pure gas zone

[0050] Repeat step S2, and the core is 100% saturated with water.

[0051] Inject gas into the core to displace water by using another displacement pump, the displacement pressure is consistent with the inlet pressure of the core during water injection, stop until the outlet end discontinuously produces water, at this time, it is considered that there is still a part of movable water in the core, and the water saturation is higher than the irreducible water saturation.

[0052] Inject gas into the core by using a high-pressure pump to simulate the gas injection process, stop when the inlet pressure of the core reaches the designed upper limit pressure, record the displacement flow rate, displacement time, and the pressure at both ends of the core, then start pressure balance after stopping injection, record the pressure at both ends of the core after balance.

[0053] Reduce the pressure of the high-pressure pump to simulate the gas production process, stop when the inlet pressure of the core reaches the designed lower limit pressure, record the displacement flow rate, displacement time, and the pressure at both ends of the core, then start pressure recovery, and record the pressure at both ends of the core after balance.

[0054] Repeat the process for 6 cycles, that is, the gas saturation of the core after 6 cycles of gas-drive pure gas zone operation tends to be stable.

[0055] c. Multi-cycle injection-production operation process of gas-water transition zone

[0056] Repeat step S2, and the core is 100% saturated with water.

[0057] Inject gas into the core to displace water by using another displacement pump, the displacement pressure is consistent with the inlet pressure of the core during water injection, stop until the outlet end discontinuously produces water, at this time, it is considered that there is still a part of movable water in the core, and the water saturation is higher than the irreducible water saturation.

[0058] Inject gas into the core by using a high-pressure pump to simulate the gas injection process, stop when the inlet pressure of the core reaches the designed upper limit pressure, record the displacement flow rate, displacement time, and the pressure at both ends of the core, then start pressure balance after stopping injection, record the pressure at both ends of the core after balance.

[0059] The pressure of the high-pressure pump is reduced to simulate the gas production process, and the process is stopped when the pressure at the inlet end of the core reaches the designed lower limit pressure, the displacement flow rate, time, and pressure at both ends of the core are recorded, and then the pressure recovery is started, and the pressure at both ends of the core after balancing is recorded.

[0060] At this time, one injection-production cycle simulation is completed, and then step S2 is repeated, the core is 100% saturated with water, and gas displacement is performed to the outlet end until continuous water production is achieved, and then the injection-production simulation of the next cycle is started, and the injection-production is repeated for 6 cycles, so that the gas saturation of the core after 6 cycles in the gas-water transition zone is obtained.

[0061] In steps 102 to 103, the gas-water relative permeability curves of multiple cores in the water-invasion gas reservoir type gas storage are obtained, the gas-water relative permeability curves of each core are standardized to obtain the gas-water standardized relative permeability curve of the gas reservoir, and the regression relationship between the relative permeability of the gas phase and the water saturation is determined according to the gas-water standardized relative permeability curve of the gas reservoir.

[0062] In specific embodiments, cores of representative reservoir types of the water-invasion gas reservoir type gas storage are selected, the gas-water relative permeability curves of each core are obtained through core displacement experiments, the gas-water relative permeability curves of each core are normalized to obtain the core gas-water standardized relative permeability curve of the gas reservoir, and the regression relationship between the relative permeability of the gas phase and the water saturation is obtained according to the core gas-water standardized relative permeability curve. As shown in Figure 2 6 plug cores of different types of reservoirs of a carbonate rock water gas reservoir are selected, core displacement experiments are carried out according to the unsteady method in “GB / T 28912-2012 Determination of Relative Permeability of Two-Phase Fluids in Rocks”, and the gas-water relative permeability curves of the cores are obtained after the experiments. The gas-water relative permeability curves of the above 6 cores are normalized to obtain the gas-water standardized relative permeability curve of the gas reservoir as shown in Figure 3 According to Figure 3 The characteristic parameters of the gas-water standardized relative permeability curve can be obtained, as shown in Table 1 below.

[0063] Table 1 Characteristic parameters of the gas-water standardized relative permeability curve

[0064] S wi (%)]] K rg (S wi )]]> S gr (%)]] K rw (S gr )]]> K rx (S wx )]]> 31.2 1 4.02 0.6798 0.16

[0065] Correspondingly, the regression relationship between the relative permeability of the gas phase and the water saturation is:

[0066] K rg = 0.00018S w 2 -0.04038S w + 2.16054.

[0067] Full-diameter long cores representing reservoir types are selected to simulate multi-cycle injection-production operation processes in different zones to obtain gas saturation of different zones after 6 cycles, as shown in Table 2.

[0068] Table 2 Simulation data of core multi-cycle injection-production operation

[0069]

[0070] From Table 2, it can be seen that the gas saturation of the pure gas zone after 6 injection-production cycles is 70.5%, the gas saturation of the gas-drive pure gas zone after 6 injection-production cycles is 46.7%, and the gas saturation of the gas-water transition zone after 6 injection-production cycles is 33.5%.

[0071] Based on the above regression relationship between gas phase relative permeability and water saturation, the gas phase relative permeability corresponding to the gas saturation of different zones after 6 cycles is calculated, which is 1, 0.5196 and 0.2713, respectively.

[0072] In step 104, the relative permeability of the gas phase is calculated according to the regression relationship between the relative permeability of the gas phase and the water saturation, and the water saturation of each zone.

[0073] In an embodiment, the regression relationship between the relative permeability of the gas phase and the water saturation satisfies the following mathematical relationship:

[0074] K rg =aS w 2 +bS w +c;

[0075] Wherein, K rg is the relative permeability of the gas phase, S w is the water saturation, and a, b and c are binomial regression coefficients.

[0076] In step 105, the binomial deliverability equation of each zone under different formation pressures is determined according to the relative permeability of the gas phase of each zone and different formation pressures.

[0077] In an embodiment, the binomial deliverability equation of each zone under different formation pressures is determined according to the relative permeability of the gas phase of each zone and different formation pressures, including:

[0078] The coefficients of the binomial deliverability equation are calculated according to the relative permeability of the gas phase of each zone and different formation pressures;

[0079] The binomial deliverability equation of each zone under different formation pressures is determined according to the coefficients of the binomial deliverability equation.

[0080] In one embodiment, the coefficients of the binomial productivity equation are calculated based on the relative permeability of the gas phase in each zone and different formation pressures, including:

[0081] Calculate the coefficients of the binomial capacity equation using the following formula:

[0082]

[0083]

[0084] Where A1 and B1 are the formation pressures p, respectively. r1 Under different binomial capacity equation coefficients, A n B n For formation pressure p rn Under different binomial productivity equation coefficients, μ g1 For formation pressure p r1 The gas viscosity at Z1 is the formation pressure p. r1 The natural gas deviation coefficient, μ gn , is the formation pressure p rn The gas viscosity at Z n For formation pressure p rn Natural gas deviation coefficient, K rg1 For formation pressure p r1 The relative permeability of the gas phase under the given conditions, K rgn For formation pressure p rn The relative permeability of the gas phase below.

[0085] In a specific embodiment, the binomial productivity equation for a gas well is:

[0086]

[0087] in,

[0088]

[0089]

[0090] K g =K·K rg

[0091] Where, p r Formation pressure, MPa; p wf q is the bottom hole flowing pressure, MPa; g For the gas production at the wellhead, 10 4 m 3 / d; A is the coefficient of the binomial capacity equation, [MPa 2 / (mPa·s)] / (10 4 m 3d); B is the binomial deliverability equation coefficient, [MPa 2 / (mPa·s)] / (10 4 m 3 / d) 2 ; μ g is the gas viscosity, mPa·s; Z is the natural gas deviation factor; T is the formation temperature, K is the reservoir effective permeability, mD; h is the reservoir effective thickness, m; r e is the gas well gas supply radius, m; r w is the wellbore radius, m; S is the skin factor; D is the non-Darcy flow coefficient, (10 4 m 3 / d) -1 ; K g is the gas phase permeability, mD; K rg is the gas phase relative permeability, mD.

[0092] The binomial deliverability equation coefficients of the set water production gas well under formation pressures p r1 and p rn are A1, B1 and A n , B n respectively, the gas viscosity and the natural gas deviation factor are μ g1 , Z1 and μ gn , Z n respectively, and the gas phase relative permeability is K rg1 and K rgn respectively. Among them, the binomial deliverability equation coefficients A1 and B1, the gas viscosity and the natural gas deviation factor μ g1 , Z1 and μ gn , Z n , and the gas phase relative permeability K rg1 and K rgn can be calculated by actual measurement and conventional experiment, and based on this, the formula for calculating the binomial deliverability equation coefficients A rn and B n under different formation pressures p n in the three zones can be derived.

[0093] A well is selected to carry out a reasonable gas production amount example calculation. The gas production binomial deliverability equation of the well under a formation pressure of 37 MPa is:

[0094]

[0095] Considering the influence of water invasion on gas phase permeability and the influence of formation pressure change on fluid properties, the binomial deliverability equation coefficients A and B values of different zones of the gas storage under different formation pressures are calculated, as shown in Table 3 below.

[0096] Table 3 Binomial deliverability equation coefficients of different zones under different formation pressures

[0097]

[0098] In step 106, the inflow performance curve from the formation to the well bottom is determined according to the binomial deliverability equation with the well bottom as a node; the outflow performance curve from the well bottom to the well head is determined according to the well head pressure and the well structure parameters; the inflow performance curve and the outflow performance curve represent the relationship curve between the gas production and the well bottom pressure.

[0099] In an embodiment, the outflow performance curve from the well bottom to the well head is determined according to the well head pressure and the well structure parameters, comprising:

[0100] obtaining the well structure parameters;

[0101] calculating the well bottom pressure corresponding to different gas productions of the water-producing gas well by using the Hagedorn-Brown method according to the well head pressure and the well structure parameters;

[0102] determining the outflow performance curve from the well bottom to the well head according to the different gas productions of the water-producing gas well and the corresponding well bottom pressures.

[0103] In a specific embodiment, the gas production corresponding to the intersection point of the inflow performance curve and the outflow performance curve is taken as the coordinated production under different formation pressures, and the reasonable gas production of the water-producing gas well is determined comprehensively in combination with the constraint conditions.

[0104] The constraint conditions include the critical liquid-carrying flow rate and the critical erosion flow rate, the reasonable gas production should be greater than the critical liquid-carrying flow rate and less than or equal to the minimum value of the coordinated production and the critical erosion flow rate, so the comprehensive determination of the reasonable gas production of the water-producing gas well in combination with the constraint conditions means that the reasonable gas production is controlled to be greater than the critical liquid-carrying flow rate and less than or equal to the minimum value of the coordinated production and the critical erosion flow rate, i.e. the reasonable gas production is the range value including the maximum gas production and the minimum gas production. In addition, if the determined gas production exceeds the aforementioned range, it indicates that the gas well cannot be produced normally under the formation pressure.

[0105] The calculation method of the critical erosion flow rate is

[0106]

[0107] wherein q e is the critical erosion flow rate, 10 4 m 3 / d; C is the critical erosion coefficient, which is related to the material, hardness, elastic modulus, impact angle, etc.; p is the oil pressure, MPa; d is the inner diameter of the oil pipe, m; γ g is the relative density of the gas; Z is the deviation factor of the natural gas; T is the temperature, K.

[0108] Critical liquid-carrying flow rate q cr The Turner formula is calculated by using the ellipsoidal droplet model, and the specific calculation formula is as follows:

[0109]

[0110] Wherein,

[0111]

[0112] Wherein, v cr is the critical liquid-carrying flow rate, m / s; A t is the cross-sectional area of the oil pipe, m 2 ; q cr is the critical liquid-carrying flow rate, 10 4 m 3 / d; p is the oil pressure, MPa; p l is the liquid density, kg / m 3 ; p g is the natural gas density, kg / m 3 ; and s is the gas-liquid interfacial tension, N / m.

[0113] In specific embodiments, the node analysis method is used, the binomial productivity equation of the water-gas well is modified based on the binomial productivity equation coefficients under different zones and different formation pressures, and then the wellbore outflow model is established according to the wellhead pressure and the well structure parameters, and the inflow dynamic curve between the bottom hole flowing pressure and the gas production and the outflow dynamic curve between the bottom hole flowing pressure and the gas production are calculated and drawn. Under the condition of the wellhead pressure of 10 MPa and the Φ114.3 mm (δ6.88 mm) oil pipe, the reasonable gas production under different formation pressures of the gas drive pure gas zone (the shaded part) is shown in the analysis diagram as shown in Figure 4 The critical erosion flow rate and the critical liquid-carrying flow rate under the wellhead pressure are calculated as 138.37×10 4 m 3 / d and 8.31×10 4 m 3 / d, respectively, and the reasonable gas production of the gas well considering the erosion effect is shown in Table 4 as follows.

[0114] Table 4 Calculation results of the maximum reasonable gas production under different formation pressures of a certain gas well (gas drive pure gas zone)

[0115]

[0116]

[0117] Under the condition of the wellhead pressure of 10 MPa and the Φ114.3 mm (δ6.88 mm) oil pipe, the comparison of the maximum reasonable gas production of the gas well under different zones and different formation pressures is shown in Table 5 as follows.

[0118] Table 5 Comparison of Calculation of Maximum Reasonable Gas Production in Different Zones of a Gas Well (10) 4 m 3 / d)

[0119] Formation pressure (MPa) S g = 70.5% S g = 46.7% S g = 33.5%]] 38 138.37 138.37 138.37 34 138.37 138.37 136.84 30 138.37 138.37 121.54 26 138.37 133.34 104.11 22 133.51 107.58 83.81

[0120] Table 5 shows that when the formation pressure is high, the reasonable gas production of this well is controlled by the tubing erosion flow rate. As the formation pressure decreases and the water saturation increases, the maximum reasonable gas production of the gas well decreases further. When the formation pressure is 22 MPa, compared to not considering water production, the maximum reasonable gas production of the gas well in the gas-water transition zone can be reduced by up to 37.22%. This paper effectively improves the accuracy of the results by illustrating the impact of water intrusion on the reasonable gas production of water-producing gas wells in different zones during multi-cycle injection and production operations in water-intruded gas reservoirs. This embodiment of the invention has important guiding significance for the allocation of injection and production capacity and the deployment of well locations and types in gas reservoirs converted from water-bearing reservoirs.

[0121] In step 107, based on the inflow dynamic curve and the outflow dynamic curve, and in conjunction with the preset constraints, the gas production rate of the water-producing gas well under different formation pressures is determined.

[0122] In one embodiment, based on the inflow dynamic curve and the outflow dynamic curve, and in conjunction with preset constraints, the gas production rate of the water-producing gas well under different formation pressures is determined, including:

[0123] The formation pressure is selected multiple times, with different formation pressures selected each time. Under the selected formation pressure, the gas production rate corresponding to the intersection of the inflow dynamic curve and the outflow dynamic curve is determined.

[0124] Based on the gas production volume corresponding to the intersection point and combined with the preset constraints, the reasonable gas production volume of the water-producing gas well under a certain formation pressure is comprehensively determined.

[0125] This invention also provides a device for determining the gas production rate of a water-bearing gas well in a water-bearing gas reservoir, as described in the following embodiments. Since the principle behind this device is similar to the method for determining the gas production rate of a water-bearing gas well in a water-bearing gas reservoir, the implementation of this device can refer to the implementation of the method for determining the gas production rate of a water-bearing gas well in a water-bearing gas reservoir; repeated details will not be elaborated further. Figure 5 The device shown includes:

[0126] The gas saturation and water saturation acquisition module 501 is used to divide the injection and production zone into multiple zones and acquire the gas saturation and water saturation of each zone during the multi-cycle injection and production process of the water-intruded gas reservoir.

[0127] The gas-water relative permeability curve acquisition module 502 is used to acquire the gas-water relative permeability curve of the core in a water-intruded gas reservoir, and to standardize the gas-water relative permeability curve of the core to obtain the gas-water standardized relative permeability curve of the gas reservoir.

[0128] The regression relationship determination module 503 is used to determine the regression relationship between the relative permeability of the gas phase and the water saturation based on the gas-water standardized relative permeability curve of the gas reservoir.

[0129] The relative permeability calculation module 504 for the gas phase is used to calculate the relative permeability of the gas phase in each zone based on the regression relationship between the relative permeability of the gas phase and the water saturation, as well as the water saturation of each zone.

[0130] The binomial productivity equation determination module 505 is used to determine the binomial productivity equation for each zone under different formation pressures based on the relative permeability of the gas phase and different formation pressures in each zone.

[0131] The inflow dynamic curve determination module 5061 is used to determine the inflow dynamic curve from the formation to the bottom of the well based on the binomial production capacity equation, with the bottom of the well as the node; the outflow dynamic curve determination module 5062 is used to determine the outflow dynamic curve from the bottom of the well to the wellhead based on the wellhead pressure and well body structural parameters; the inflow dynamic curve and the outflow dynamic curve represent the relationship curve between the gas production rate and the bottom of the well pressure.

[0132] The gas production volume determination module 507 is used to determine the gas production volume of water-producing gas wells under different formation pressures based on the inflow dynamic curve, the outflow dynamic curve, and preset constraints.

[0133] In one embodiment, the regression relationship between the relative permeability of the gas phase and the water saturation satisfies the following mathematical equation:

[0134] K rg =aS w 2 +bS w +c;

[0135] Among them, K rg S represents the relative permeability of the gas phase. w Let be the water saturation level, and a, b, and c be the binomial regression coefficients.

[0136] In one embodiment, the binomial capacity equation determination module 505 is specifically used for:

[0137] The coefficients of the binomial productivity equation are calculated based on the relative permeability of the gas phase in each zone and the different formation pressures.

[0138] Based on the coefficients of the binomial productivity equation, the binomial productivity equation for each zone under different formation pressures is determined.

[0139] In one embodiment, the binomial capacity equation determination module 505 is specifically used for:

[0140] Calculate the coefficients of the binomial capacity equation using the following formula:

[0141]

[0142]

[0143] Where A1 and B1 are the formation pressures p, respectively. r1 Under different binomial capacity equation coefficients, A n B n For formation pressure p rn Under different binomial productivity equation coefficients, μ g1 For formation pressure p r1 The gas viscosity at Z1 is the formation pressure p. r1 The natural gas deviation coefficient, μ gn , is the formation pressure p rn The gas viscosity at Z n For formation pressure p rn Natural gas deviation coefficient, K rg1 For formation pressure p r1 The relative permeability of the gas phase under the given conditions, K rgn For formation pressure p rn The relative permeability of the gas phase below.

[0144] In one embodiment, the outflow dynamic curve determination module 5052 is specifically used for:

[0145] Obtain wellbore structural parameters;

[0146] Based on wellhead pressure and wellbore structural parameters, the Hagedorn-Brown method was used to calculate the bottom hole pressure of a water-producing gas well under different gas production rates.

[0147] Based on the different gas production rates and corresponding bottom pressures of the water-producing gas wells, the outflow dynamic curve from the bottom of the well to the wellhead is determined.

[0148] In one embodiment, the gas sampling volume determination module 507 is specifically used for:

[0149] The formation pressure is selected multiple times, with different formation pressures selected each time. Under the selected formation pressure, the gas production rate corresponding to the intersection of the inflow dynamic curve and the outflow dynamic curve is determined.

[0150] Based on the gas production volume corresponding to the intersection point and combined with the preset constraints, the gas production volume of the water-producing gas well under a certain formation pressure is comprehensively determined.

[0151] This invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method for determining the gas production of water-producing gas wells in a water-invaded gas reservoir.

[0152] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method for determining the gas production of water-producing wells in a water-invaded gas reservoir.

[0153] This invention also provides a computer program product, which includes a computer program that, when executed by a processor, implements the method for determining the gas production of water-producing gas wells in a water-invaded gas reservoir.

[0154] In this embodiment of the invention, the injection-production zone is divided into multiple zones. During the multi-cycle injection-production process of a water-intruded gas reservoir, the gas saturation and water saturation of each zone are obtained. Gas-water relative permeability curves from multiple core samples are obtained in the water-intruded gas reservoir. The gas-water relative permeability curves of each core sample are standardized to obtain the gas-water standardized relative permeability curve of the gas reservoir. Based on the gas-water standardized relative permeability curve of the gas reservoir, the regression relationship between the relative permeability of the gas phase and the water saturation is determined. Based on the regression relationship between the relative permeability of the gas phase and the water saturation, and the gas-water relative permeability of each zone... The water saturation of the gas phase in each zone is considered, and the relative permeability of the gas phase in each zone is calculated. Based on the relative permeability of the gas phase in each zone and different formation pressures, a binomial production capacity equation is determined for each zone under different formation pressures. Taking the bottom of the well as the node, the inflow dynamic curve from the formation to the bottom of the well is determined according to the binomial production capacity equation. Based on the wellhead pressure and wellbore structural parameters, the outflow dynamic curve from the bottom of the well is determined. The inflow dynamic curve and the outflow dynamic curve represent the relationship between the gas production rate and the bottom of the well pressure. Based on the inflow dynamic curve, the outflow dynamic curve, and preset constraints, the gas production rate of the water-producing gas well is determined. In the above process, this embodiment of the invention considers the impact of water intrusion on the gas production rate of different zones during multi-cycle injection and production operation of water-intrusion gas reservoirs. By using the inflow dynamic curve, the outflow dynamic curve, and preset constraints, the gas production rate of water-producing gas wells under different formation pressures is determined, thereby rationally designing the injection and production operation indicators of the gas reservoir and improving the capacity and production rate of water-intrusion gas reservoirs during multi-cycle operation.

[0155] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0156] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0157] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0158] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0159] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for determining the gas production rate of water-producing gas wells in a water-inundated gas reservoir, characterized in that, include: The injection and production zone is divided into multiple zones. During the multi-cycle injection and production process of the water-intruded gas reservoir, the gas saturation and water saturation of each zone are obtained respectively. In a water-intrusive gas reservoir, the relative permeability curves of gas and water from multiple core samples were obtained. The gas-water relative permeability curves of each core sample were standardized to obtain the standardized relative permeability curves of gas and water in the gas reservoir. Based on the gas-water standardized relative permeability curve of the gas reservoir, the regression relationship between the relative permeability of the gas phase and the water saturation was determined. Based on the regression relationship between the relative permeability of the gas phase and the water saturation, and the water saturation of each zone, the relative permeability of the gas phase in each zone is calculated. Based on the relative permeability of the gas phase in each zone and the different formation pressures, the binomial productivity equations for each zone under different formation pressures are determined. Using the bottom of the well as the node, the inflow dynamic curve from the formation to the bottom of the well is determined according to the binomial production capacity equation; the outflow dynamic curve from the bottom of the well to the wellhead is determined according to the wellhead pressure and well body structural parameters; the inflow dynamic curve and the outflow dynamic curve represent the relationship curve between gas production and bottom of the well pressure. Based on the inflow and outflow dynamic curves, and combined with preset constraints, the gas production rate of the water-producing gas well under different formation pressures is determined.

2. The method as described in claim 1, characterized in that, The regression relationship between the relative permeability of the gas phase and the water saturation satisfies the following mathematical equation: K rg =aS w 2 +bS w +c; Among them, K rg S represents the relative permeability of the gas phase. w Let be the water saturation level, and a, b, and c be the binomial regression coefficients.

3. The method as described in claim 1, characterized in that, Based on the relative permeability of the gas phase in each zone and different formation pressures, the binomial productivity equations for each zone under different formation pressures are determined, including: The coefficients of the binomial productivity equation are calculated based on the relative permeability of the gas phase in each zone and the different formation pressures. Based on the coefficients of the binomial productivity equation, the binomial productivity equation for each zone under different formation pressures is determined.

4. The method as described in claim 3, characterized in that, Based on the relative permeability of the gas phase in each zone and different formation pressures, the coefficients of the binomial productivity equation are calculated, including: Calculate the coefficients of the binomial capacity equation using the following formula: Where A1 and B1 are the formation pressures p, respectively. r1 Under different binomial capacity equation coefficients, A n B n For formation pressure p rn Under different binomial productivity equation coefficients, μ g1 For formation pressure p r1 The gas viscosity at Z1 is the formation pressure p. r1 The natural gas deviation coefficient, μ gn , is the formation pressure p rn The gas viscosity at Z n For formation pressure p rn Natural gas deviation coefficient, K rg1 For formation pressure p r1 The relative permeability of the gas phase under the given conditions, K rgn For formation pressure p rn The relative permeability of the gas phase below.

5. The method as described in claim 1, characterized in that, Based on wellhead pressure and wellbore structural parameters, determine the outflow dynamic curve from the bottom of the well to the wellhead, including: Obtain wellbore structural parameters; Based on wellhead pressure and wellbore structural parameters, the Hagedorn-Brown method was used to calculate the bottom hole pressure of a water-producing gas well under different gas production rates. Based on the different gas production rates and corresponding bottom pressures of the water-producing gas wells, the outflow dynamic curve from the bottom of the well to the wellhead is determined.

6. The method as described in claim 1, characterized in that, Based on the inflow and outflow dynamic curves, and in conjunction with preset constraints, the gas production rate of the water-producing gas well under different formation pressures is determined, including: The formation pressure is selected multiple times, with different formation pressures selected each time. Under the selected formation pressure, the gas production rate corresponding to the intersection of the inflow dynamic curve and the outflow dynamic curve is determined. Based on the gas production volume corresponding to the intersection point and combined with the preset constraints, the gas production volume of the water-producing gas well under a certain formation pressure is comprehensively determined.

7. A device for determining the gas production rate of a water-bearing gas well in a water-inundated gas reservoir, characterized in that, include: The gas saturation and water saturation acquisition module is used to divide the injection and production zone into multiple zones, and to acquire the gas saturation and water saturation of each zone during the multi-cycle injection and production process of the water-intruded gas reservoir. The gas-water relative permeability curve acquisition module is used to acquire the gas-water relative permeability curves of multiple core samples in a water-intruded gas reservoir. The gas-water relative permeability curves of each core sample are standardized to obtain the gas-water standardized relative permeability curves of the gas reservoir. The regression relationship determination module is used to determine the regression relationship between the relative permeability of the gas phase and the water saturation based on the gas-water standardized relative permeability curve of the gas reservoir. The relative permeability calculation module for the gas phase is used to calculate the relative permeability of the gas phase in each zone based on the regression relationship between the relative permeability of the gas phase and the water saturation, as well as the water saturation of each zone. The binomial productivity equation determination module is used to determine the binomial productivity equation for each zone under different formation pressures based on the relative permeability of the gas phase and different formation pressures in each zone. The inflow dynamic curve determination module is used to determine the inflow dynamic curve from the formation to the bottom of the well based on the binomial production capacity equation, with the bottom of the well as the node; the outflow dynamic curve determination module is used to determine the outflow dynamic curve from the bottom of the well to the wellhead based on the wellhead pressure and well structure parameters; the inflow dynamic curve and the outflow dynamic curve represent the relationship curve between gas production and bottom hole pressure. The gas production volume determination module is used to determine the gas production volume of water-producing gas wells under different formation pressures based on the inflow dynamic curve, the outflow dynamic curve, and preset constraints.

8. The apparatus as claimed in claim 7, characterized in that, The regression relationship between the relative permeability of the gas phase and the water saturation satisfies the following mathematical equation: K rg =aS w 2 +bS w +c; Among them, K rg S represents the relative permeability of the gas phase. w Let be the water saturation level, and a, b, and c be the binomial regression coefficients.

9. The apparatus as claimed in claim 7, characterized in that, The binomial capacity equation determination module is specifically used for: The coefficients of the binomial productivity equation are calculated based on the relative permeability of the gas phase in each zone and the different formation pressures. Based on the coefficients of the binomial productivity equation, the binomial productivity equation for each zone under different formation pressures is determined.

10. The apparatus as claimed in claim 9, characterized in that, The binomial capacity equation determination module is specifically used for: Calculate the coefficients of the binomial capacity equation using the following formula: Where A1 and B1 are the formation pressures p, respectively. r1 Under different binomial capacity equation coefficients, A n B n For formation pressure p rn Under different binomial productivity equation coefficients, μ g1 For formation pressure p r1 The gas viscosity at Z1 is the formation pressure p. r1 The natural gas deviation coefficient, μ gn , is the formation pressure p rn The gas viscosity at Z n For formation pressure p rn Natural gas deviation coefficient, K rg1 For formation pressure p r1 The relative permeability of the gas phase under the given conditions, K rgn For formation pressure p rn The relative permeability of the gas phase below.

11. The apparatus as claimed in claim 7, characterized in that, The outflow dynamic curve determination module is specifically used for: Obtain wellbore structural parameters; Based on wellhead pressure and wellbore structural parameters, the Hagedorn-Brown method was used to calculate the bottom hole pressure of a water-producing gas well under different gas production rates. Based on the different gas production rates and corresponding bottom pressures of the water-producing gas wells, the outflow dynamic curve from the bottom of the well to the wellhead is determined.

12. The apparatus as claimed in claim 7, characterized in that, The gas extraction volume determination module is specifically used for: The formation pressure is selected multiple times, with different formation pressures selected each time. Under the selected formation pressure, the gas production rate corresponding to the intersection of the inflow dynamic curve and the outflow dynamic curve is determined. Based on the gas production volume corresponding to the intersection point and combined with the preset constraints, the gas production volume of the water-producing gas well under a certain formation pressure is comprehensively determined.

13. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 6.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method of any one of claims 1 to 6.

15. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method of any one of claims 1 to 6.

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