Production allocation method for gas well of condensate gas reservoir type gas storage

Abstract

The invention belongs to the technical field of oil and gas exploitation methods, and particularly relates to a production allocation method for a gas well of a condensate gas reservoir type gas storage. The production allocation method for the gas well of the condensate gas reservoir type gas storage comprises the following steps that the radius range Rb of condensate oil separated out by well periphery reservoir chromatography of a single well under different production allocation gas rates Q is determined; determining a relational expression of reservoir pressure p and Q of the condensate gas reservoir type gas storage single well in the Rb range; calculating the total amount Qo of condensate oil separated by reservoir chromatography around the single well; determining a relational expression between the gas condensate production quantity Qo'and Q of the single well; according to the method, the gas preparation and production rate Qe is obtained through the fact that the Qo is equal to the Qo ', the separated condensate oil is completely displaced out of the stratum by the high-speed gas flow, the influence of the condensate oil is avoided, and therefore the purposes that the gas preparation and production rate is increased, and the peak regulation capacity of the gas storage is improved are achieved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction methods, specifically to a production allocation method for gas wells in condensate gas reservoirs. Background Technology

[0002] Underground gas storage facilities bear the crucial responsibility of peak shaving and supply assurance during winter. During peak shaving, these facilities require high-volume throughput operation, making efficient operation under such conditions paramount. Currently, the production allocation method for condensate gas reservoirs typically follows traditional methods. However, because condensate oil precipitates when the pressure of condensate gas is below the dew point pressure, obstructing gas flow channels and reducing the well's production capacity, production allocation for condensate gas reservoirs must ensure the formation pressure remains above the dew point pressure. However, significant pressure drops occur near the wellbore during condensate gas well production, and these drops increase with the production volume. To ensure the formation pressure does not fall below the dew point pressure, traditional condensate gas reservoir production allocation requires limiting the production volume. This contradicts the high-volume throughput operation mode of gas storage facilities, making traditional condensate gas reservoir production allocation methods unsuitable for condensate gas reservoirs.

[0003] Chinese invention patent CN113250749A, published on August 13, 2021, discloses a simulation method and system for condensate gas reservoirs. This method calculates the water intrusion rate of the condensate gas reservoir based on the mass balance equation, and then combines the phase characteristics of condensate oil and gas and the relative permeability curves of gas and water to conduct a full life-cycle numerical simulation of the condensate gas reservoir, determining parameters such as the reservoir capacity and working gas volume. While the method provides calculation methods for parameters such as the reservoir capacity and working gas volume, it does not explain the allocation of gas well production.

[0004] In actual gas production, high-speed gas flow has a certain displacement effect on condensate oil. If all the precipitated condensate oil is displaced from the formation, the impact of condensate oil can be avoided, thereby increasing the gas production volume and improving the peak-shaving capacity of the gas storage facility. Currently, there is no mature production allocation method for gas wells in condensate gas reservoirs. In view of this situation, a method for rational production allocation of gas wells in condensate gas reservoirs is needed to guide the production allocation of condensate gas reservoirs and ensure the efficient operation of the gas storage facility. Summary of the Invention

[0005] This invention provides a production allocation method for gas wells in condensate gas reservoirs, solving the problem of low gas production volume in traditional condensate gas reservoir production allocation methods.

[0006] To solve the above-mentioned technical problems, the technical solution of the production allocation method for condensate gas reservoir-type gas storage wells of the present invention is as follows:

[0007] A production allocation method for gas wells in a condensate gas reservoir includes the following steps:

[0008] 1) Based on the nonlinear radial steady-flow formula for gas, determine the radius range R of condensate oil precipitation in the reservoir around the well of a single well in a condensate gas reservoir type under different gas production rates Q. b ;

[0009] 2) Based on the two-phase steady-state flow formula for oil and gas, determine the R value of a single well in a condensate gas reservoir. b The relationship between reservoir pressure p and Q within the specified range;

[0010] 3) Based on the experimentally obtained functional relationship between the condensate oil precipitation amount f(p,o) and the reservoir pressure p, the total amount of condensate oil precipitated around the wellbore of a single well, Q, is then calculated. o :

[0011]

[0012] Among them, R w Where is the wellbore radius, h is the reservoir thickness, φ is the effective porosity of the reservoir rock, and r is the distance from any point in the wellbore to the central axis of the wellbore.

[0013] 4) Determine the condensate oil production rate Q of a single well in a condensate gas reservoir based on the two-phase steady-state flow formula for oil and gas. o The relationship between Q and Q;

[0014] 5) Using Q o =Q o The corresponding gas production volume Q at that time e Determine the gas production volume of the gas wells in the condensate gas reservoir type gas storage facility during actual gas production.

[0015] This invention improves upon existing technology and provides a production allocation method for gas wells in condensate gas reservoirs. This method involves adjusting the condensate oil production rate Q of a single well in a condensate gas reservoir. o 'Equals the total amount of condensate oil precipitated from the reservoir around a single well, Q' o The gas production volume at a given time is the actual gas production volume of the gas well in the condensate gas reservoir. This ensures that the precipitated condensate oil is completely displaced from the formation by the high-speed gas flow, and avoids the influence of condensate oil. This achieves the purpose of increasing the gas production volume and improving the peak-shaving capacity of the gas reservoir. If the total amount of condensate oil precipitated from the reservoir around the gas well is higher than the amount of condensate oil produced, the gas well's production capacity will decrease due to the influence of the precipitated condensate oil. If the total amount of condensate oil precipitated from the reservoir around the gas well is lower than the amount of condensate oil produced, the peak-shaving capacity of the gas reservoir cannot be fully utilized, thus reducing economic benefits.

[0016] To further increase the radius range R of condensate oil precipitation in the wellbore reservoir bThe accuracy of the variation with the gas production rate Q is preferably determined by the radius R of the condensate oil precipitated from the wellbore reservoir in step 1). b The calculation method is as follows:

[0017]

[0018] Where, p e To supply pressure to a single well; p b For dew point pressure; μ g Z is the viscosity of condensate gas; Z is the condensate gas deviation coefficient; T is the formation temperature; Z sc T is the gas deviation coefficient under standard conditions. sc p represents the gas temperature under standard conditions. sc ρ is the gas pressure under standard conditions. sc ρ is the density of produced condensate under standard conditions; k is the effective permeability of the reservoir; h is the reservoir thickness; α is the geometric characteristic parameter of the pore structure affecting inertial resistance; Q is the gas production rate per well; R e Provide the radius for a single well.

[0019] To further improve in R b The accuracy of the reservoir pressure p within the range of varying gas production Q is preferably such that, in step 2), the single well of the condensate gas reservoir type gas storage facility is within R... b The relationship between reservoir pressure p and Q within the specified range is as follows:

[0020]

[0021] Where, k g This represents the condensate gas permeability.

[0022] To further increase the condensate oil production Q of a single well o The accuracy of the change in gas production Q is preferably related to the condensate oil production Q of a single well in a condensate gas reservoir in step 4). o The relationship between 'Q' and 'Q' is as follows:

[0023]

[0024] Where, k ro B represents the relative permeability of condensate oil. o The volume factor of condensate oil is μ. o This refers to the viscosity of the condensate oil.

[0025] To further improve the accuracy of reservoir pressure p calculation, preferably, the condensate gas permeability k g First, determine k under any pressure. rg / k ro Relationship:

[0026]

[0027] Then, by combining the relationship curves between the relative permeability of the condensate gas phase and the oil phase and the oil saturation, the permeability of the condensate gas phase and the oil phase can be determined:

[0028]

[0029] Where GOR is the gas-to-oil ratio produced by the gas well; k rg k represents the relative permeability of the condensate gas. ro k represents the relative permeability of condensate oil. o This represents the permeability of condensate oil. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the production method of the condensate gas reservoir gas storage well of the present invention;

[0031] Figure 2 R in Embodiment 1 of the present invention b R e R w Location relationship diagram;

[0032] Figure 3 This is a graph showing the relationship between the viscosity of the condensate gas and the pressure in Example 1 of the present invention.

[0033] Figure 4 This is a graph showing the relationship between the condensate gas deviation coefficient and pressure in Example 1 of the present invention;

[0034] Figure 5 This is a graph showing the relationship between viscosity and pressure of the condensate oil in Example 1 of the present invention.

[0035] Figure 6 This is a graph showing the relationship between the volume coefficient of condensate oil and pressure in Example 1 of the present invention.

[0036] Figure 7 This is a graph showing the relationship between the relative permeability of the gas phase / oil phase and the oil saturation in Example 1 of the present invention.

[0037] Figure 8 The amount of condensate oil q in Example 1 of the present invention o A schematic diagram of the width of the integral ring;

[0038] Figure 9 This is a graph showing the relationship between condensate oil precipitation and reservoir pressure in Example 1 of the present invention.

[0039] Figure 10 Q in Embodiment 1 of the present invention o ' / Q o The curve showing the relationship between the production volume Q and the gas output. Detailed Implementation

[0040] The technical concept of the production allocation method for condensate gas reservoir-type gas storage wells of the present invention is as follows:

[0041] A production allocation method for gas wells in a condensate gas reservoir includes the following steps:

[0042] 1) Based on the nonlinear radial steady-flow formula for gas, determine the radius range R of condensate oil precipitation in the reservoir around the well of a single well in a condensate gas reservoir type under different gas production rates Q. b ;

[0043] 2) Based on the two-phase steady-state flow formula for oil and gas, determine the R value of a single well in a condensate gas reservoir. b The relationship between reservoir pressure p and Q within the specified range;

[0044] 3) Based on the experimentally obtained functional relationship between the condensate oil precipitation amount f(p,o) and the reservoir pressure p, the total amount of condensate oil precipitated around the wellbore of a single well, Q, is then calculated. o :

[0045]

[0046] Among them, R w Where is the wellbore radius, h is the reservoir thickness, φ is the effective porosity of the reservoir rock, and r is the distance from any point in the wellbore to the central axis of the wellbore.

[0047] 4) Determine the condensate oil production rate Q of a single well in a condensate gas reservoir based on the two-phase steady-state flow formula for oil and gas. o The relationship between Q and Q;

[0048] 5) Using Q o =Q o The corresponding gas production volume Q at that time e Determine the gas production volume of the gas wells in the condensate gas reservoir type gas storage facility during actual gas production.

[0049] When using traditional condensate gas reservoir well production allocation methods for extraction, in order to ensure that the formation pressure is above the dew point pressure and to prevent condensate gas from precipitating condensate oil when the pressure is below the dew point pressure, thereby occupying the gas seepage channel and reducing the gas production capacity of the gas well, the production volume needs to be limited during production allocation. This results in a low production volume, which in turn affects peak shaving and supply guarantee during winter.

[0050] This invention improves the condensate oil production rate Q of a single well in a condensate gas reservoir. o 'Equals the total amount of condensate oil precipitated from the reservoir around a single well, Q' oThe gas production volume at a given time is the actual gas production volume of a gas well in a condensate gas reservoir. This ensures that the precipitated condensate oil is completely displaced from the formation by the high-speed gas flow, avoiding the influence of condensate oil and thus achieving the goal of increasing the gas production volume and improving the peak-shaving capacity of the gas reservoir. If the total amount of condensate oil precipitated from the reservoir around the gas well is higher than the amount of condensate oil produced, the gas well's production capacity will decrease due to the influence of the precipitated condensate oil. If the total amount of condensate oil precipitated from the reservoir around the gas well is lower than the amount of condensate oil produced, since a larger gas production volume results in a larger peak-shaving capacity (i.e., the gas reservoir's production capacity), the amount of condensate oil precipitated is positively correlated with the gas production volume. If the total amount of condensate oil precipitated from the reservoir around the gas well is lower than the amount of condensate oil produced, it indicates that there is still room for further increase in the gas production volume, and the peak-shaving capacity of the gas reservoir can be even greater. In other words, the gas production volume can be further increased at this time, and the peak-shaving capacity of the gas reservoir cannot be fully utilized, thus reducing economic benefits.

[0051] It is understood that the physical parameters used in this invention can be obtained through conventional testing, wherein the single-well supply pressure p e The dew point pressure p was obtained through static pressure testing during the well shut-in balancing period. b condensate gas viscosity μ g Condensate gas deviation coefficient Z, condensate oil viscosity μ o The volume factor B of condensate oil o The viscosity μ of the condensate gas at a certain gas temperature and pressure can all be obtained through high-pressure physical property experiments. g Condensate gas deviation coefficient Z, condensate oil viscosity μ o The volume factor B of condensate oil o The relationship between condensate production and reservoir pressure p can be determined separately; the functional relationship f(p,o) between condensate production and reservoir pressure p can also be obtained by fitting experimental data obtained from high-pressure physical property tests; formation temperature T is obtained from well logging data; reservoir effective permeability k and the geometric characteristic parameter α of pore structure affecting inertial resistance are obtained through core experiments; the gas-oil production ratio GOR of the gas well is obtained from the historical production data of the well; wellbore radius R w Measurements showed that the condensate gas deviation coefficient under standard conditions was 1.0; the condensate gas temperature under standard conditions was 293 K; the condensate gas pressure under standard conditions was 0.101 MPa; and the extracted condensate gas density under standard conditions was 0.76 g / m³. 3 .

[0052] The schematic diagram of the formulation method of the present invention is as follows: Figure 1 As shown, the required physical parameters are obtained through the above conventional tests. Using the corresponding physical parameters and the nonlinear radial steady-flow formula for gas, the radius range R of condensate oil precipitation in the reservoir around the well of a single well in a condensate gas reservoir type is determined under different gas production rates Q. b(i.e., the range of condensate oil precipitation in the reservoir), based on the two-phase steady flow formula for oil and gas, determine the range of condensate gas reservoir-type gas storage single wells within R. b The relationship between reservoir pressure p and Q within the range (i.e., wellbore pressure distribution) is used to calculate the total amount of condensate Q precipitated from the reservoir around a single well. o Then, the condensate oil production Q of a single well in a condensate gas reservoir type gas storage facility is determined by the two-phase steady flow formula for oil and gas. o 'Compare and determine the reasonable gas production volume for a single well.'

[0053] The embodiments of the present invention will be further described below with reference to specific examples.

[0054] I. Specific Embodiments of the Production Allocation Method for Condensate Gas Reservoir-Type Gas Wells of the Present Invention

[0055] The production allocation method for gas wells in the condensate gas reservoir type gas storage facility of the present invention is as follows:

[0056] 1) Based on the nonlinear radial steady-flow formula for gas, determine the radius range R of condensate oil precipitation in the reservoir around the well of a single well in a condensate gas reservoir type under different gas production rates Q. b :

[0057]

[0058] Where, p e For single-well supply pressure, MPa; p b Here, ρ is the dew point pressure, MPa; μ is the pressure. g Z is the viscosity of condensate gas, mPa·s; Z is the condensate gas deviation coefficient, dimensionless; T is the formation temperature, K; Z sc T is the gas deviation coefficient under standard conditions, dimensionless; sc The gas temperature under standard conditions is expressed in Kelvin (p). sc ρ represents the gas pressure under standard conditions, in MPa; sc The density of the produced condensate under standard conditions is expressed in kg / m³. 3 k is the effective permeability of the reservoir, mD; h is the reservoir thickness, m; α is the geometric characteristic parameter of the pore structure affecting inertial resistance, dimensionless; Q is the gas production rate per well, m³. 3 / d;R e The radius of the single well supply is in meters (m).

[0059] The radius R of condensate oil precipitation in the well perimeter reservoir b Single well supply radius R e Wellbore radius R w Positional relationships such as Figure 2 As shown, R b R is the maximum distance between the point where condensate oil precipitates from the reservoir around the well and the centerline of the wellbore (i.e., the radius of condensate oil precipitation from the reservoir around the well).e The depth was obtained through unsteady gauging testing; in this embodiment, it was 472m. The single-well supply pressure was p. e The single-well supply pressure p in this embodiment is obtained from the static pressure test during the shut-in balancing period. e 52 MPa; dew point pressure p b The dew point pressure p in this embodiment was obtained from high-pressure property experiments. b The pressure is 38 MPa; the viscosity and deviation coefficient of the condensate gas were obtained from high-pressure physical property experiments and determined by the relationship curves between the viscosity and deviation coefficient of the condensate gas and the pressure. The relationship curves between the viscosity and pressure are shown in the figure below. Figure 3 As shown in the figure, the relationship between the condensate gas deviation coefficient and pressure is as follows: Figure 4 As shown, the viscosity μ of the condensate gas in this formula is... g Pressure taken: 45 MPa (single well supply pressure p) e 52MPa and dew point pressure p b The viscosity of condensate gas under the conditions of 38 MPa (average value) and 121℃ is 0.036 mPa·s. In this formula, the condensate gas deviation coefficient Z is taken as 45 MPa (single well supply pressure p). e 52MPa and dew point pressure p b The condensate gas deviation coefficient under the conditions of 38 MPa (average value) and 121℃ is 1.05; the formation temperature T is obtained from well logging data, and in this example, the formation temperature T is 394K; the condensate gas deviation coefficient Z under standard conditions is... sc The value is 1.0; the condensate gas temperature T under standard conditions is... sc The pressure of the condensate gas under standard conditions is 293K; sc The pressure is 0.101 MPa; the density ρ of the extracted condensate gas under standard conditions is... sc 1.0 kg / m 3 The effective permeability k of the reservoir was obtained from core experiments, and in this embodiment, the effective permeability k is 4.2 mD; the reservoir thickness h was obtained from well logging, and in this embodiment, the reservoir thickness h is 40 m; the pore structure geometric characteristic parameter α affecting inertial resistance was obtained from core experiments, and in this embodiment, α is 56.5; the single-well production rate is the design value, and in this embodiment, the single-well production rate Q is taken as 10 × 10⁻⁶. 4 m 3 Taking / d as an example, the radius R of condensate oil precipitation from the wellbore reservoir is... b To obtain the desired value, when the production rate Q of a single well is taken as 10 × 10 4 m 3 The radius R of condensate oil precipitated from the wellbore reservoir was calculated at / d. b It is 3.1m.

[0060] 2) Based on the two-phase steady-state flow formula for oil and gas, determine the R value of a single well in a condensate gas reservoir. bThe relationship between reservoir pressure p and Q within the specified range is as follows:

[0061]

[0062] Where r is the distance from any point in the wellbore to the central axis of the wellbore; k g This represents the condensate gas permeability.

[0063] The condensate gas permeability k in the formula g First, determine k under any pressure. rg / k ro Relationship:

[0064]

[0065] For steady two-phase flow of oil and gas, the producing gas-oil ratio of a gas well is constant. The viscosity of condensate, the viscosity of condensate gas, and the volume coefficient of condensate are all functions of pressure. Therefore, the ratio k of the relative permeability of the gas phase to the oil phase at any pressure can be determined. rg / k ro ;

[0066] By combining the relationship curves between the relative permeability of the condensate gas phase and the oil phase and the oil saturation, the corresponding oil saturation is determined by the ratio of the relative permeability of the gas phase to the oil phase in the curve, and then the relative permeability k of the gas phase and the oil phase is obtained. rg k ro This allows for the determination of the permeability k of the condensate gas phase and oil phase. g k o :

[0067]

[0068] Where GOR is the gas-to-oil ratio produced by the gas well, m 3 / m 3 ;k rg k is the relative permeability of the condensate gas, dimensionless; ro k is the relative permeability of condensate oil, dimensionless; o For condensate oil permeability, mD; μ o The viscosity of the condensate oil is given in mPa·s; μ. g B is the viscosity of the condensate gas, in mPa·s; o is the volume coefficient of condensate oil, dimensionless.

[0069] The gas-oil production ratio (GOR) of the gas well was obtained from the well's historical production data. In this example, the GOR is 4800 m³ / s. 3 / m 3 The viscosity-pressure relationship curve of condensate oil is shown in the figure below. Figure 5 As shown, based on the viscosity μ of the condensate oil oThe relationship curve with pressure was determined, with a pressure of 45 MPa (single well supply pressure p). e 52MPa and dew point pressure p b Under conditions of an average pressure of 38 MPa and a temperature of 121 °C, the viscosity μ of the condensate oil was... o The pressure is 0.42 mPa·s; the relationship between the condensate oil volume factor and pressure is shown in the graph below. Figure 6 As shown, based on the condensate oil volume factor B o The relationship curve with pressure was determined, with a pressure of 45 MPa (single well supply pressure p). e 52MPa and dew point pressure p b Under conditions of an average pressure of 38 MPa and a temperature of 121 °C, the condensate oil volume factor B o The value is 1.38; the relationship between the relative permeability of the gas / oil phase and the oil saturation is shown in the graph below. Figure 7 As shown.

[0070] 3) Based on the functional relationship f(p,o) between condensate oil precipitation and reservoir pressure p obtained from high-pressure physical property experiments, calculate the total amount of condensate oil Q precipitated from the reservoir around a single well. o ;

[0071] The wellbore reservoir is divided into several concentric rings, each with a width of dr, such as... Figure 8 As shown, the amount of condensate oil precipitated within the annulus is q. o It can be represented as:

[0072] q o =2πrhφdr·f(p,o)

[0073] In the formula, q o The amount of condensate oil precipitated within the ring, m 3 ;

[0074] The total amount of condensate oil precipitated from the reservoir around a single well, Q o for:

[0075]

[0076] Among them, R w Where φ is the wellbore radius, h is the reservoir thickness, and φ is the effective porosity of the reservoir rock.

[0077] Wellbore radius R w The wellbore radius R in this embodiment was obtained through measurement. w The effective porosity φ of the reservoir rock is 0.127 m; this can be obtained from rock experiments, and in this example, φ is 13%. The relationship between condensate oil precipitation and reservoir pressure obtained from high-pressure property experiments is shown in the following graph. Figure 9As shown, the functional relationship f(p,o) between condensate oil precipitation and reservoir pressure p is obtained through curve fitting. When the gas production rate Q is 10 × 10⁻⁶... 4 m 3 When / d, the total amount of condensate oil precipitated from the reservoir around a single well, Q, is calculated. o It is 1.18m 3 .

[0078] The functional relationship between condensate precipitation and reservoir pressure p is f(p,o):

[0079] f(p,o)=-0.0107p 2 +0.4318p -0.7126

[0080] 4) Determine the condensate oil production rate Q of a single well in a condensate gas reservoir based on the two-phase steady-state flow formula for oil and gas. o The relationship between Q and Q;

[0081] During steady two-phase flow of oil and gas, the following conditions must be met for the oil component:

[0082]

[0083] By substitution, the pseudo-pressure function is obtained:

[0084]

[0085] In the above formula, C is the function term required for the integral function, which can be eliminated in subsequent calculations.

[0086] The condensate oil production Q of a single well in a condensate gas reservoir is... o 'Can be represented as:

[0087]

[0088] in,

[0089] k ro B represents the relative permeability of condensate oil. o The volume factor of condensate oil is μ. o This refers to the viscosity of the condensate oil.

[0090] p w The wellbore pressure at the production zone, in MPa, can be calculated using the following formula:

[0091]

[0092] In the formula, p o Wellhead pressure, MPa;

[0093] γ gThe relative density of the extracted condensate gas is dimensionless;

[0094] d is the inner diameter of the oil pipe, in meters;

[0095] W g The mass flow rate of the extracted condensate gas is expressed in kg / d.

[0096] M g The relative molecular mass of the extracted condensate is dimensionless;

[0097] H is the vertical distance from the wellhead to the production layer, in meters;

[0098] f g is the friction coefficient, which is dimensionless.

[0099] Wellhead pressure p o The wellhead pressure in this embodiment is 5 MPa, which can be measured. The relative density of the produced condensate gas can be obtained experimentally; in this embodiment, it is the relative density γ of the produced condensate gas. g The value is 0.78; the inner diameter d of the oil pipe can be obtained by measurement, and in this embodiment, the inner diameter of the oil pipe is 0.13m; the mass flow rate W of the extracted condensate gas is... g To determine the production gas volume Q and the density ρ of the condensate gas produced under standard conditions. sc The product of, i.e., W g =Q·ρ sc The relative molecular mass M of the extracted condensate gas g The relative molecular mass M of the extracted condensate gas in this embodiment can be obtained experimentally. g The vertical distance H from the wellhead to the production layer can be obtained by measurement. In this embodiment, the vertical distance H from the wellhead to the production layer is 3075m.

[0100] The formula for calculating the friction coefficient is:

[0101]

[0102] In the formula, e is the roughness of the tubing wall, which is usually taken as 0.00001524m;

[0103] R e The Reynolds number is calculated using the following formula:

[0104]

[0105] When the gas production volume Q is 10×10 4 m 3 / d, calculate the corresponding wellbore pressure p at the production layer. w Substituting this into the formula for calculating the oil production of a single well in a condensate gas reservoir, we can obtain the condensate oil production of 1.28 m³ under this gas production ratio. 3 .

[0106] 5) Take the gas production rate Q of a single well in a condensate gas reservoir for different types of condensate gas reservoirs, and calculate the condensate oil production rate Q of a single well in a condensate gas reservoir. o 'Total amount of condensate oil precipitated from the reservoir around a single well Q o Q obtained o ' / Q o The relationship curve between the production gas volume Q and the output gas volume is shown in the figure below. Figure 10 As shown, Q o =Q o The corresponding gas production volume Q at that time e This is the production volume Q used when the gas well in a condensate gas reservoir is actually producing gas. e 10.7×10 4 m 3 / d. If the total amount of condensate oil precipitated from the reservoir around a single well is Q... o Higher than the condensate oil production rate Q o The precipitation of condensate oil will lead to a decrease in the gas production capacity of gas wells. If the total amount of condensate oil precipitated from the reservoir around a single well is Q... o Lower than the condensate oil production rate Q o If this is not done, the peak-shaving capacity of the gas storage facility cannot be fully utilized, thus reducing economic benefits.

[0107] For Well Chu 1, a condensate gas reservoir, if the traditional condensate gas well production allocation method is used, the production volume needs to be limited to ensure that the formation pressure is above the dew point pressure. The calculated production volume per well is 6.5 × 10⁻⁶. 4 m 3 / d; while the gas production per well calculated using the production allocation method provided by this invention is 10.7 × 10 4 m 3 / d, after increasing the gas production volume on-site, the gas well maintained stable production for a long period. Compared with the traditional gas well production allocation method for condensate gas reservoirs, the initial daily oil production increased from 0.6m³ / day. 3 / d increased to 1.1m 3 / d, the cycle gas production increased by 271.3×10 compared to the original expectation. 4 m 3 The gas production allocation method provided by this invention can significantly increase the gas production volume and improve the peak-shaving capacity of gas storage facilities.

[0108] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A production allocation method for gas wells in a condensate gas reservoir, characterized in that, Includes the following steps: 1) Based on the nonlinear radial steady-flow formula for gas, determine the radius range R of condensate oil precipitation in the reservoir around the well of a single well in a condensate gas reservoir type under different gas production rates Q. b ; 2) Based on the two-phase steady-state flow formula for oil and gas, determine the R value of a single well in a condensate gas reservoir. b The relationship between reservoir pressure p and Q within the specified range; 3) Based on the experimentally obtained functional relationship between the condensate oil precipitation amount f(p,o) and the reservoir pressure p, the total amount of condensate oil precipitated around the wellbore of a single well, Q, is then calculated. o : Among them, R w Where is the wellbore radius, h is the reservoir thickness, φ is the effective porosity of the reservoir rock, and r is the distance from any point in the wellbore to the central axis of the wellbore. 4) Determine the condensate oil production rate Q of a single well in a condensate gas reservoir based on the two-phase steady-state flow formula for oil and gas. o ’ The relationship with Q; 5) Using Q o =Q o ’ The corresponding gas production volume Q at that time e Determine the gas production volume of the gas wells in the condensate gas reservoir type gas storage facility during actual gas production.

2. The production allocation method for gas wells in a condensate gas reservoir as described in claim 1, characterized in that, The radius R of the condensate oil precipitated from the wellbore reservoir in step 1) b The calculation method is as follows: Where, p e To supply pressure to a single well; p b For dew point pressure; μ g Z is the viscosity of condensate gas; Z is the condensate gas deviation coefficient; T is the formation temperature; Z sc T is the gas deviation coefficient under standard conditions. sc p represents the gas temperature under standard conditions. sc ρ is the gas pressure under standard conditions. sc ρ is the density of produced condensate under standard conditions; k is the effective permeability of the reservoir; h is the reservoir thickness; α is the geometric characteristic parameter of the pore structure affecting inertial resistance; Q is the gas production rate per well; R e Provide the radius for a single well.

3. The production allocation method for gas wells in a condensate gas reservoir as described in claim 1, characterized in that, In step 2), the single well of the condensate gas reservoir type gas storage facility is in R b The relationship between reservoir pressure p and Q within the specified range is as follows: Where, k g This represents the condensate gas permeability.

4. The production allocation method for gas wells in a condensate gas reservoir as described in claim 1, characterized in that, In step 4), the condensate oil production Q of a single well in a condensate gas reservoir-type gas storage facility... o ’ The relationship with Q is as follows: Where, k ro B represents the relative permeability of condensate oil. o The volume factor of condensate oil is μ. o This refers to the viscosity of the condensate oil.

5. The production allocation method for gas wells in a condensate gas reservoir as described in claim 3, characterized in that, The condensate gas permeability k g First, determine k under any pressure. rg / k ro Relationship: Then, by combining the relationship curves between the relative permeability of the condensate gas phase and the oil phase and the oil saturation, the permeability of the condensate gas phase and the oil phase can be determined: Where GOR is the gas-to-oil ratio produced by the gas well; k rg k represents the relative permeability of the condensate gas. ro k represents the relative permeability of condensate oil. o This represents the permeability of condensate oil.

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