Methods, systems, devices, media for evaluating open flow potential of a gas well

Abstract

The method, system, device and medium for evaluating the open flow capacity of a gas well in the early stage of reservoir reconstruction include the following steps: setting a metering device at the wellhead of a gas production well; collecting the daily oil, gas and liquid production of the wellhead of the gas production well by the metering device; obtaining the weight M of the total output fluid at the wellhead of the gas production well according to the daily oil, gas and liquid production of the wellhead of the gas production well; calculating the density p of the mixed-phase fluid in the wellbore; obtaining the flow pressure gradient G according to the density p of the mixed-phase fluid in the wellbore DS and the bottom hole flowing pressure P wf ; obtaining the absolute open flow capacity q DS according to the flow pressure gradient G wf and the bottom hole flowing pressure P AOF by using the point method empirical formula, and evaluating the actual productivity of the gas production well. The present application can quickly and real-timely calculate the flow pressure gradient in the wellbore of the production well and the bottom hole flowing pressure. The method is simple, practical and effective, and can timely and accurately evaluate the actual productivity of the gas production well.

Description

Technical Field

[0001] This invention belongs to the technical field of early accurate evaluation after gas well reservoir stimulation, and specifically relates to methods, systems, equipment, and media for evaluating the unobstructed flow rate in the early stage of gas well reservoir stimulation. Background Technology

[0002] Accurately evaluating the production capacity of gas wells is fundamental to the scientific development of gas fields and is increasingly valued by oilfield developers. However, a series of condensate gas fields discovered in the Tarim Gas Field are characterized by deep burial, high pressure, and high temperature, resulting in large gas production from wells. Lowering pressure gauges to the middle of the gas layer for testing is extremely difficult and risky, often making it impossible to measure the bottom hole pressure. This poses a challenge to evaluating the production capacity of gas wells. Furthermore, during early-stage blowout testing after reservoir stimulation in both new and old wells, varying amounts of drilling fluid and stimulation fluid are lost within the wellbore, further complicating the accurate calculation of bottom hole flowing pressure and making it impossible to obtain the actual production capacity of gas wells in a timely manner. The absolute unobstructed flow rate of a gas well is a crucial indicator reflecting its potential production capacity, especially for newly discovered exploratory and development wells, where it is essential to promptly ascertain the magnitude of the absolute unobstructed flow rate.

[0003] Current methods for calculating wellbore pressure gradient and bottomhole pressure after reservoir stimulation in new and old wells cannot be obtained immediately and effectively through testing. In the early stages of fluid discharge, there is always stimulation fluid or other liquids in the wellbore, resulting in low wellhead oil pressure. Directly using the gas phase gradient to calculate the bottomhole pressure and thus the unobstructed flow rate will lead to an underestimation and cannot provide an accurate evaluation. Summary of the Invention

[0004] The purpose of this invention is to provide a method, system, equipment, and medium for evaluating the unobstructed flow rate in the early stage of gas well reservoir stimulation, in order to address the needs of oil and gas reservoir development researchers. This invention addresses the problem that after reservoir stimulation in new and old wells, it is not possible to obtain the wellbore flowing pressure gradient and bottom hole flowing pressure in a timely and effective manner through testing. In the early stage of fluid drainage, there is always stimulation fluid or other liquids in the wellbore, resulting in low wellhead oil pressure. Therefore, directly using the gas phase gradient to calculate the bottom hole flowing pressure and thus the unobstructed flow rate is too low.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for evaluating the early-stage unobstructed flow rate of gas well reservoir stimulation includes the following steps:

[0007] Install metering equipment at the wellhead of the gas producing well;

[0008] Daily oil production (M) at the wellhead of the gas producing well is collected using metering equipment. o 、Air V g Liquid production M L ;

[0009] The weight M of the total fluid produced at the wellhead is obtained based on the daily production of oil, gas, and liquid at the wellhead.

[0010] The density ρ of the mixed-phase fluid in the wellbore is obtained by calculating the ratio of the sum of the produced gas volume and the liquid volume in the formation, V, to the total weight M of the produced fluid at the wellhead.

[0011] The flowing pressure gradient G is obtained from the density ρ of the mixed-phase fluid inside the wellbore. DS and bottom hole flowing pressure P wf ;

[0012] According to the flow pressure gradient G DS and bottom hole flowing pressure P wf The absolute unobstructed flow rate q can be obtained using the empirical formula of the one-point method. AOF To evaluate the actual production capacity of gas production wells.

[0013] Furthermore, the metering equipment includes mass sensors and gas flow sensors.

[0014] Furthermore, the weight M of the total fluid produced at the wellhead specifically includes:

[0015] Oil, gas, and liquefied petroleum products are taken from the wellhead or bottom for testing. Laboratory analysis is then used to determine the formation gas volume factor (B) of the fluids. g Natural gas relative density ρ g Crude oil density ρ o and liquid sample density ρ L ;

[0016] Based on the basic data of a single well, the production zone of the single well is obtained, and the deep vertical depth H of the production zone is calculated.

[0017] Based on the relative density ρ of natural gas g air density ρ (constant) 空气 Calculate the weight M of the produced gas. g Combined with metered production oil M o Product fluid M l The total weight M of the produced fluid is obtained;

[0018] M = V g ×ρ g ×ρ 空气 +M o +M l .

[0019] Furthermore, calculating the sum of the produced gas volume and the liquid volume within the formation, V, specifically includes:

[0020] Through the formation gas volume factor B g Calculate the gas production V g Volume V under geological conditions g地 Liquid sample density ρ L Calculate the output liquid volume V l V = Vg地 +V l The density ρ of the mixed-phase fluid inside the wellbore is obtained by the ratio M / V of M to V.

[0021] Furthermore, V g地＝ V g ×B g V l =M l / ρ l .

[0022] Furthermore, the flow pressure gradient G DS and bottom hole flowing pressure P wf Specifically:

[0023] The change in flow pressure per unit depth within the wellbore = the product of the density of the mixed-phase fluid within the wellbore and the gravitational acceleration g = ρ × g;

[0024] Flow pressure gradient G DS The change in flowing pressure per unit depth during well production in oil and gas wells (G) DS =ρ×g;

[0025] Bottom hole flowing pressure P wf The deep flowing pressure P in the producing formation is calculated based on wellhead oil pressure data and wellbore flowing pressure gradient. wf =P l +G DS ×H÷10 6 .

[0026] Furthermore, absolutely unobstructed flow rate q AOF Using the empirical formula q (one-point method) AOF = (1.1986 × V) g ) / (1-(P wf / P R ) 2 ) 0.7614 The single-well free flow rate is calculated based on formation pressure, bottom hole flowing pressure, and corresponding wellhead gas production; P R : Formation pressure.

[0027] Furthermore, systems for evaluating the early-stage unobstructed flow rate of gas well reservoir stimulation include:

[0028] The data acquisition module is used to install metering equipment at the wellhead of the gas producing well; the metering equipment collects the daily oil production (M) at the wellhead of the gas producing well. o 、Air V g Liquid production M L ;

[0029] The module for calculating the total fluid produced at the wellhead is used to obtain the total fluid produced at the wellhead, M, based on the daily production of oil, gas, and liquid at the wellhead of the gas producing well.

[0030] The wellbore miscible fluid density calculation module is used to calculate the ratio of the sum of the produced gas volume and the liquid volume in the formation, V, to the weight M of the total produced fluid at the wellhead, and thus obtain the wellbore miscible fluid density ρ.

[0031] The calculation and analysis module is used to obtain the flowing pressure gradient G based on the density ρ of the miscible fluid in the wellbore. DS and bottom hole flowing pressure P wf According to the flow pressure gradient G DS and bottom hole flowing pressure P wf The absolute unobstructed flow rate q can be obtained using the empirical formula of the one-point method. AOF To evaluate the actual production capacity of gas production wells.

[0032] Furthermore, a computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements steps such as those of a method for evaluating early unobstructed flow rates in gas well reservoir stimulation.

[0033] Furthermore, a computer-readable storage medium stores a computer program that, when executed by a processor, implements steps such as those of a method for evaluating early unobstructed flow rates in gas well reservoir stimulation.

[0034] Compared with the prior art, the present invention has the following technical effects:

[0035] The core of this invention is a method for determining the flowing pressure gradient under miscible conditions within the wellbore. Field verification has shown that the calculated results match the actual measurements obtained during wireline well testing with a 99% agreement rate and an error range of approximately 1%. The unobstructed flow rate of gas wells evaluated using this method accurately reflects the well's production capacity; it can quickly and in real-time calculate the flowing pressure gradient within the wellbore and the bottomhole flowing pressure. The method is simple, practical, and effective, providing timely and accurate evaluation of the actual production capacity of gas production wells. Attached Figure Description

[0036] Figure 1 This is a flowchart of the present invention; Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings:

[0038] Please see Figure 1 Methods for evaluating the early-stage unobstructed flow rate of gas well reservoir stimulation

[0039] First, the daily oil, gas, and liquid production (M) from the gas-producing wellhead is measured using wellhead metering equipment. o V g M L and the gas-oil ratio R gol Obtain wellhead oil pressure data Pl ;

[0040] Oil, gas, and liquefied petroleum products are taken from the wellhead or bottom for testing. Laboratory analysis is then used to determine the formation gas volume factor (B) of the fluids. g Natural gas relative density ρ g Crude oil density ρ o Liquid sample density ρ L (Note: The formation gas volume coefficient can also be calculated using Saphir software.)

[0041] Based on the basic data of a single well, the production zone of the single well is obtained, and the deep vertical depth H of the production zone is calculated.

[0042] Based on the relative density ρ of natural gas g Given the constant air density ρ_air, calculate the weight M of the produced gas. g Combined with metered production oil M o Product fluid M l The total weight M of the produced fluid is obtained; then, the formation gas volume factor B is used. g Calculate the gas production V g Volume V under geological conditions g Density ρ of ground and liquid samples L Calculate the output liquid volume V l The density ρ of the mixed-phase fluid inside the wellbore can be obtained by the ratio of M to V (M / V).

[0043] The change in flow pressure per unit depth within the wellbore = the product of the density of the mixed-phase fluid within the wellbore and the gravitational acceleration g = ρ × g;

[0044] Flow pressure gradient G DS The change in flowing pressure per unit depth during well production (G) of an oil and gas well. DS =ρ×g);

[0045] Bottom hole flowing pressure P wf Calculate the mid-depth flowing pressure (P) in the producing formation based on wellhead oil pressure data and wellbore flowing pressure gradient. wf =P l +G DS ×H÷10^6).

[0046] Absolutely unobstructed flow rate q AOF Using the one-point empirical formula (q) AOF = (1.1986 × V) g ) / (1-(P wf / P R ) 2 ) 0.7614 The unobstructed flow rate of a single well is calculated based on the formation pressure, bottom hole flowing pressure, and corresponding wellhead gas production.

[0047] Calculation principle:

[0048] 1. Unobstructed flow rate: Calculated using an empirical formula based on a single-point method;

[0049] 2. Bottom hole flowing pressure: Calculate the mid-deep flowing pressure of the producing formation based on wellhead oil pressure data and wellbore flowing pressure gradient;

[0050] 3. Flow pressure gradient: The change in flow pressure per unit depth within the wellbore during well production;

[0051] 4. Change in flow pressure per unit depth within the wellbore: the product of the density of the mixed-phase fluid within the wellbore and the gravitational acceleration g;

[0052] 5. Density of mixed-phase fluid in wellbore: The weight of fluid per unit volume of wellbore.

[0053] M o： Oil produced from the wellhead, kg

[0054] M L： Wellhead produced fluid weight, kg

[0055] V g : Gas produced from the wellhead, m 3

[0056] B g Formation gas volume factor, m 3

[0057] ρ g Relative density of the produced gas fluid

[0058] ρ L : Density of the produced liquid, kg / m³ 3

[0059] V: Volume under gas- and liquid-producing formation conditions, in meters. 3

[0060] V g地 : Volume of gas-producing formation under specific conditions, in m 3

[0061] V l : Volume of produced fluid under formation conditions, in m 3

[0062] ρ: Density of miscible fluid in the wellbore, kg / m 3

[0063] g: acceleration due to gravity, g = 10 N / kg

[0064] G DS Flow pressure gradient, Pa / m

[0065] P l Wellhead oil pressure, MPa

[0066] H: Medium-deep (vertical depth) of the producing layer, m

[0067] P wf Bottom hole flowing pressure, MPa

[0068] P R Formation pressure, MPa

[0069] q AOF Absolutely unobstructed flow rate, m 3 / d

[0070] constant ρ 空气 1.293 kg / m³ 3

[0071] Example:

[0072] 1. Measured flowing pressure gradient of well A1 in gas reservoir A: 0.620 (MPa / 100m); Measured flowing pressure at medium depth in the producing layer: 66.39 MPa

[0073] On the day of testing, the A1 well produced 58,300 m³ of gas at the wellhead. 3 Daily oil production is 0.15 tons, daily water production is 82.68 tons, and the gas-oil ratio is 388667 m. 3 / t, hydraulic pressure 30.26MPa

[0074] Well A1 has a mid-to-deep vertical depth of 5827.00m in the producing formation.

[0075] Formation gas volume factor (m 3 / m 3 0.0023 (obtainable from PVT test analysis reports and software calculations)

[0076] Relative density of natural gas: 0.577 (obtainable from natural gas analysis reports)

[0077] Formation water density: 1.1623 g / cm³ 3 (This can be obtained from the product water analysis report)

[0078] Constant ρ_air: 1.293 kg / m³ 3

[0079] Step 1: Calculate the flowing pressure gradient inside the wellbore.

[0080]

[0081] Step 2: Calculate the deep flow pressure in the producing formation.

[0082] P=30.26+0.00616×5827(MPa)=66.15(MPa)

[0083] Following well completion and stimulation, the B1 well in gas reservoir B underwent a 4-day blowout test. The specific production rate, calculated flowing pressure gradient, bottom hole flowing pressure, production pressure differential, and unhindered flow rate results are shown in the table below:

[0084] Table 1. Production Data from Well B1 Test

[0085]

[0086] The following are embodiments of the apparatus of the present invention, which can be used to execute embodiments of the method of the present invention. For details not disclosed in the apparatus embodiments, please refer to the embodiments of the method of the present invention.

[0087] In another embodiment of the present invention, a system for evaluating the early-stage unobstructed flow rate of gas well reservoir stimulation is provided, which can be used to implement the above-mentioned method for evaluating the early-stage unobstructed flow rate of gas well reservoir stimulation. Specifically, the system includes:

[0088] The data acquisition module is used to install metering equipment at the wellhead of the gas producing well; the metering equipment collects the daily oil production (M) at the wellhead of the gas producing well. o 、Air V g Liquid production M L ;

[0089] The module for calculating the total fluid produced at the wellhead is used to obtain the total fluid produced at the wellhead, M, based on the daily production of oil, gas, and liquid at the wellhead of the gas producing well.

[0090] The wellbore miscible fluid density calculation module is used to calculate the ratio of the sum of the produced gas volume and the liquid volume in the formation, V, to the weight M of the total produced fluid at the wellhead, and thus obtain the wellbore miscible fluid density ρ.

[0091] The calculation and analysis module is used to obtain the flowing pressure gradient G based on the density ρ of the miscible fluid in the wellbore. DS and bottom hole flowing pressure P wf According to the flow pressure gradient G DS and bottom hole flowing pressure P wf The absolute unobstructed flow rate q can be obtained using the empirical formula of the one-point method. AOF To evaluate the actual production capacity of gas production wells.

[0092] In one possible implementation,

[0093] All relevant content of each step involved in the aforementioned embodiment of a method for evaluating the early unobstructed flow rate of gas well reservoir stimulation can be referenced to the functional description of the corresponding functional module of a system for evaluating the early unobstructed flow rate of gas well reservoir stimulation in the present invention, and will not be repeated here.

[0094] The module division in this embodiment of the invention is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the invention can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0095] In another embodiment of the present invention, a computer device is provided, comprising a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to achieve a corresponding method flow or corresponding function; the processor described in this embodiment of the present invention can be used for the following operations.

[0096] In another embodiment of the present invention, a storage medium is provided, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the operating system of the terminal. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps in the above embodiments.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for evaluating the early-stage unobstructed flow rate of gas well reservoir stimulation, characterized in that, Includes the following steps: Install metering equipment at the wellhead of the gas producing well; Daily oil production (M) at the wellhead of the gas producing well is collected using metering equipment. o 、Air V g Liquid production M L ; The weight M of the total fluid produced at the wellhead is obtained based on the daily production of oil, gas, and liquid at the wellhead. The density ρ of the mixed-phase fluid in the wellbore is obtained by calculating the ratio of the sum of the produced gas volume and the liquid volume in the formation, V, to the total weight M of the produced fluid at the wellhead. The flowing pressure gradient G is obtained from the density ρ of the mixed-phase fluid inside the wellbore. DS and bottom hole flowing pressure P wf ; According to the flow pressure gradient G DS and bottom hole flowing pressure P wf The absolute unobstructed flow rate q can be obtained using the empirical formula of the one-point method. AOF To evaluate the actual production capacity of gas production wells; The weight M of the total fluid produced at the wellhead specifically includes: Oil, gas, and liquefied petroleum products are taken from the wellhead or bottom for testing. Laboratory analysis is then used to determine the formation gas volume factor (B) of the fluids. g Natural gas relative density ρ g Crude oil density ρ o and liquid sample density ρ L ; Based on the basic data of a single well, the production zone of the single well is obtained, and the deep vertical depth H of the production zone is calculated. Based on the relative density ρ of natural gas g air density ρ (constant) 空气 Calculate the weight M of the produced gas. g Combined with metered production oil M o Product fluid M l The total weight M of the produced fluid is obtained; M=V g ×ρ g ×ρ 空气 +M o +M l ; The calculation of the sum of the produced gas volume and the liquid volume within the formation, V, specifically includes: Through the formation gas volume factor B g Calculate the gas production V g Volume V under geological conditions g地 Liquid sample density ρ L Calculate the output liquid volume V l V=V g地 +V l The density ρ of the mixed-phase fluid inside the wellbore is obtained by the ratio M / V of M and V. V g地= V g ×B g ;V l =M l / ρ l ; Flow pressure gradient G DS and bottom hole flowing pressure P wf Specifically: The change in flow pressure per unit depth within the wellbore = the product of the density of the mixed-phase fluid within the wellbore and the gravitational acceleration g = ρ × g; Flow pressure gradient G DS The change in flowing pressure per unit depth during well production in oil and gas wells (G) DS =ρ×g; Bottom hole flowing pressure P wf Calculate the mid-deep flowing pressure of the producing formation based on wellhead oil pressure data and wellbore flowing pressure gradient. P wf = P l + G DS ×H÷10 6 ; Absolutely unobstructed flow rate q AOF Using a one-point empirical formula q AOF =(1.1986× V g ) / (1-( P wf / P R ) 2 ) 0.7614 The single-well free flow rate is calculated based on formation pressure, bottom hole flowing pressure, and corresponding wellhead gas production; P R : Formation pressure.

2. The method for evaluating the early-stage unobstructed flow rate of gas well reservoir stimulation according to claim 1, characterized in that, Metering equipment includes mass sensors and gas flow sensors.

3. A system for evaluating the early-stage unobstructed flow rate of gas well reservoir stimulation, characterized in that, The method for evaluating the early-stage unobstructed flow rate of gas well reservoir stimulation as described in claim 1 includes: The data acquisition module is used to install metering equipment at the wellhead of the gas producing well; the metering equipment collects the daily oil production (M) at the wellhead of the gas producing well. o 、Air V g Liquid production M L ; The module for calculating the total fluid produced at the wellhead is used to obtain the total fluid produced at the wellhead, M, based on the daily production of oil, gas, and liquid at the wellhead of the gas producing well. The wellbore miscible fluid density calculation module is used to calculate the ratio of the sum of the produced gas volume and the liquid volume in the formation, V, to the weight M of the total produced fluid at the wellhead, and thus obtain the wellbore miscible fluid density ρ. The calculation and analysis module is used to obtain the flowing pressure gradient G based on the density ρ of the miscible fluid in the wellbore. DS and bottom hole flowing pressure P wf According to the flow pressure gradient G DS and bottom hole flowing pressure P wf The absolute unobstructed flow rate q can be obtained using the empirical formula of the one-point method. AOF To evaluate the actual production capacity of gas production wells.

4. 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 steps of a method for evaluating the early unobstructed flow rate of a gas well reservoir as described in any one of claims 1 to 2.

5. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of a method for evaluating the early unobstructed flow rate of a gas well reservoir as described in any one of claims 1 to 2.

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