CN115898365A - Method and device for calculating residual gas production capacity - Google Patents

Abstract

A method and device for calculating remaining gas production capacity, the method comprising: calculating and obtaining the seepage area of the first formation when the horizontal well or vertical well produces gas according to the daily gas production pressure and gas production flow rate of the horizontal well or vertical well of the gas storage, Radial permeability, vertical permeability and skin coefficient; according to the change of gas production system, calculate the change law of seepage area in the preset period and the seepage area of the first formation to obtain the seepage area of the second formation, and build an improved model of seepage area; The functional relationship between permeability and rock pore volume multiple, obtain the equivalent permeability composed of radial permeability and vertical permeability, and build a permeability improvement model; the seepage area of the second formation, equivalent permeability and skin coefficient Bring in the simulated binomial equation to obtain the laminar flow coefficient and turbulent flow coefficient during gas production, and construct the gas production capacity equation; construct the remaining gas production capacity calculation model based on the seepage area improvement model, permeability improvement model and gas production capacity equation, Calculate the remaining gas production capacity.

Description

Remaining gas production capacity calculation method and device

Technical Field

The invention relates to the field of gas reservoir engineering, and in particular to a method and a device for calculating residual gas production capacity.

Background Art

In order to supply gas to the market in winter, the gas storage needs to use the gas absorbed in the summer to keep the storage full. The important indicator to measure how quickly the gas storage fills up with gas is the gas production capacity. The gas production capacity of the entire gas storage is composed of gas storage wells one by one, among which horizontal wells or vertical wells are the type with the largest gas production. However, accurately obtaining the remaining gas production capacity of the horizontal or vertical wells in the current cycle is a technical problem that plagues the scientific research and business managers of gas storage.

At present, there are limited means to obtain the actual gas production capacity of horizontal wells or vertical wells in gas storage, and basically no consideration is given to the changes in the formation seepage range and formation permeability during the actual gas production process of the gas storage well. For example, the most widely used method is well testing. For example, the horizontal well or vertical well injection capacity equation described in a paper in "Natural Gas Industry" in February 2019 is directly derived from the well testing test. This method does not take into account the difference in the formation seepage range during the well testing test and the actual gas injection in the gas storage, and does not consider the changes in the formation permeability during subsequent gas injection. It is easy to know from the classical seepage law of gas in the formation that the formation seepage range is negatively correlated with the gas production capacity of the gas well. Conventional well testing obtains a larger formation supply range than the actual one, which will inevitably lead to a smaller calculated gas production capacity. The conventional method of obtaining gas production capacity does not accurately consider the formation seepage range during the gas production process, which results in poor accuracy of the obtained gas production capacity.

Therefore, most of the current methods for obtaining the remaining gas production capacity of horizontal wells or vertical wells in the current cycle of gas storage reservoirs do not accurately consider the range of formation seepage and changes in formation permeability during the actual gas production process of gas storage wells. There is a large gap between the predicted results and the actual operating results, and a relatively accurate method is urgently needed.

Summary of the invention

The present invention aims to accurately consider the actual seepage range and formation permeability changes of the formation during subsequent gas production in the current cycle of a horizontal well or a vertical well of a gas storage reservoir, and to provide a method and device for calculating the remaining gas production capacity.

To achieve the above-mentioned purpose, the present invention provides a method for calculating the remaining gas production capacity, the method comprising: calculating the first formation seepage area, radial permeability, vertical permeability and skin coefficient when the horizontal well or vertical well is producing gas according to the daily gas production pressure and gas production flow rate of the horizontal well or vertical well of the gas storage reservoir; calculating the change law of the seepage area within a preset period according to the change of the gas production system, adjusting the first formation seepage area according to the change law to obtain the second formation seepage area, and constructing a seepage area improvement model according to the second formation seepage area and the first formation seepage area; calculating the change law according to the permeability and the rock pore volume multiple. The functional relationship between the radial permeability and the vertical permeability is obtained to obtain the equivalent permeability composed of the radial permeability and the vertical permeability, and a permeability improvement model is constructed according to the equivalent permeability; the seepage area of the second formation, the equivalent permeability and the skin coefficient are substituted into the simulated binomial equation to obtain the laminar coefficient and the turbulent coefficient during gas production, and a gas production capacity equation is constructed according to the laminar coefficient and the turbulent coefficient; a residual gas production capacity calculation model is constructed according to the improved seepage area model, the improved permeability model and the gas production capacity equation, and the residual gas production capacity of the horizontal well or vertical well of the gas storage reservoir is calculated by the residual gas production capacity calculation model.

In the above-mentioned remaining gas production capacity calculation method, preferably, calculating the first formation seepage area, radial permeability and vertical permeability during gas production in the horizontal well or vertical well according to the daily gas production pressure and gas production flow rate of the horizontal well or vertical well of the gas storage reservoir includes: calculating the first formation seepage area, radial permeability and vertical permeability by fitting the actual curve with the theoretical plate according to the daily gas production pressure and gas production flow rate of the horizontal well or vertical well of the gas reservoir.

In the above remaining gas production capacity calculation method, preferably, adjusting the first formation seepage area according to the change rule to obtain the second formation seepage area comprises:

The seepage area of the second formation is calculated by the following formula:

Area2＝Area1×(Q2×Q1+Q2)÷(Q2×Q1+Q1);

In the above formula, Area2 is the seepage area of the second formation, Area1 is the seepage area of the first formation, Q1 is the production ratio of the current horizontal well or vertical well to the adjacent wells in the gas storage reservoir, and Q2 is the production ratio of the horizontal well or vertical well to the adjacent wells in the gas storage reservoir within the preset period.

In the above remaining gas recovery capacity calculation method, preferably, constructing a permeability improvement model according to the equivalent permeability comprises the following formula:

Kf＝f[(Kk)n,V];

In the above formula, Kf is the equivalent permeability of the horizontal well or vertical well of the gas storage reservoir within a preset period, Kk is the equivalent permeability composed of the radial permeability and the vertical permeability, V is the rock pore volume multiple, and f[(Kk)n, V] is the relationship function obtained by regression of experimental data.

In the above-mentioned remaining gas production capacity calculation method, preferably, the laminar coefficient and turbulent coefficient during gas production are obtained by substituting the seepage area of the second formation, the equivalent permeability and the skin coefficient into the pseudo-binomial equation:

When the target well is a horizontal well, the laminar flow coefficient and turbulent flow coefficient are calculated by the following formula:

Area2＝3.14159×R_eh×R_ehβ＝7.644×10¹⁰/K^1.2；

Area2＝3.14159×R _eh ×R _eh β＝7.644×10 ¹⁰ /K ^1.2 ;

When the target well is a vertical well, the laminar flow coefficient and turbulent flow coefficient are calculated by the following formula:

为平均粘度；

为气体平均压缩因子；T为储气库地层温度；K为储气地层拟化渗透率；h为地层厚度；L为水平段长度；r_w为井眼半径；K_v为地层垂向渗透率；K_h为地层水平方向渗透率；r_g为气体相对密度；r_e为地层泄压半径。In the above formula, A is the laminar coefficient of the horizontal well; B is the turbulent coefficient of the horizontal well;

is the average viscosity;

is the average gas compression factor; T is the gas storage reservoir formation temperature; K is the simulated permeability of the gas storage formation; h is the formation thickness; L is the horizontal section length; _rw is the wellbore radius; _Kv is the vertical permeability of the formation; _Kh is the horizontal permeability of the formation; _rg is the relative density of gas; _{and re} is the formation pressure relief radius.

In the above-mentioned remaining gas production capacity calculation method, preferably, the gas production capacity calculation model is the following formula:

_Pe2 ^- _Pwf2 =AQ ^{+ BQ2} ;

In the above formula, _Pe is the average formation pressure; _Pwf is the bottom hole flowing pressure; A is the laminar flow coefficient of the gas well; B is the turbulent flow coefficient of the gas well; Q is the daily gas production of the gas well.

The present invention also provides a device for calculating the remaining gas production capacity, the device comprising an analysis module, an improvement module, a construction module and a calculation module; the analysis module is used to calculate the first formation seepage area, radial permeability, vertical permeability and skin coefficient when the horizontal well or vertical well is producing gas according to the daily gas production pressure and gas production flow rate of the horizontal well or vertical well of the gas storage reservoir; the improvement module is used to calculate the change law of the seepage area within a preset period according to the change of the gas production system, adjust the first formation seepage area according to the change law to obtain the second formation seepage area, and construct a seepage area improvement model according to the second formation seepage area and the first formation seepage area; and The functional relationship between the volume multiples of the pore volume of the rock is obtained to obtain the equivalent permeability composed of the radial permeability and the vertical permeability, and a permeability improvement model is constructed according to the equivalent permeability; the construction module is used to bring the seepage area of the second formation, the equivalent permeability and the skin coefficient into the simulated binomial equation to obtain the laminar coefficient and the turbulent coefficient during gas production, and a gas production capacity equation is constructed according to the laminar coefficient and the turbulent coefficient; the calculation module is used to construct a residual gas production capacity calculation model according to the seepage area improvement model, the permeability improvement model and the gas production capacity equation, and the residual gas production capacity of the horizontal well or vertical well of the gas storage reservoir is calculated by the residual gas production capacity calculation model.

In the above-mentioned remaining gas production capacity calculation device, preferably, the improved module also includes: obtaining the seepage area, radial permeability and vertical permeability of the first formation by fitting the actual curve with the theoretical chart according to the daily gas production pressure and gas production flow rate of the horizontal well or vertical well of the gas reservoir.

In the above-mentioned remaining gas production capacity calculation device, preferably, the improvement module further comprises:

The seepage area of the second formation is calculated by the following formula:

Area2＝Area1×(Q2×Q1+Q2)÷(Q2×Q1+Q1);

In the above formula, Area2 is the seepage area of the second formation, Area1 is the seepage area of the first formation, Q1 is the production ratio of the current horizontal well or vertical well to the adjacent wells in the gas storage reservoir, and Q2 is the production ratio of the horizontal well or vertical well to the adjacent wells in the gas storage reservoir within the preset period.

In the above-mentioned remaining gas production capacity calculation device, preferably, the building module comprises:

When the target well is a horizontal well, the laminar flow coefficient and turbulent flow coefficient are calculated by the following formula:

Area2＝3.14149×R_eh×R_ehβ＝7.644×10¹⁰/K^1.2；

Area2＝3.14149×R _eh ×R _eh β＝7.644×10 ¹⁰ /K ^1.2 ;

When the target well is a vertical well, the laminar flow coefficient and turbulent flow coefficient are calculated by the following formula:

为平均粘度；

为气体平均压缩因子；T为储气库地层温度；K为储气地层拟化渗透率；h为地层厚度；L为水平段长度；r_w为井眼半径；K_v为地层垂向渗透率；K_h为地层水平方向渗透率；r_g为气体相对密度；r_e为地层泄压半径。In the above formula, A is the laminar coefficient of the horizontal well; B is the turbulent coefficient of the horizontal well;

is the average viscosity;

is the average gas compression factor; T is the gas storage reservoir formation temperature; K is the simulated permeability of the gas storage formation; h is the formation thickness; L is the horizontal section length; _rw is the wellbore radius; _Kv is the vertical permeability of the formation; _Kh is the horizontal permeability of the formation; _rg is the relative density of gas; _{and re} is the formation pressure relief radius.

The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above method when executing the computer program.

The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program for executing the above method.

The present invention fully considers the seepage range and the change law of formation permeability during gas production in the gas storage, and the accuracy of its calculation results is greatly improved, showing strong technical advantages. In addition, compared with conventional well testing, which requires interrupting the gas production of the gas storage to test the instrument, the data required by the present invention is only the daily gas production data, which does not need to delay the precious gas production time of the gas storage, and does not need to pay the instrument testing fee, etc., so it shows a relatively obvious economic advantage; at the same time, it will provide more accurate remaining gas production capacity for the gas storage currently in operation, and thus provide a scientific basis for accurately predicting the overall gas production capacity of the gas storage in summer.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute a limitation of the present invention. In the drawings:

FIG1 is a schematic flow chart of a method for calculating the remaining gas production capacity provided by an embodiment of the present invention;

FIG2 is a schematic diagram of the structure of a residual gas production capacity calculation device provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention.

DETAILED DESCRIPTION

The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that as long as there is no conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

In addition, the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be performed in an order different from that shown here.

Please refer to FIG. 1 , a method for calculating the remaining gas production capacity provided by the present invention includes:

S101 calculates the first formation seepage area, radial permeability, vertical permeability and skin coefficient when the horizontal well or vertical well is producing gas according to the daily production pressure and production flow rate of the horizontal well or vertical well of the gas storage reservoir;

S102: calculating a change rule of the seepage area within a preset period according to the change of the gas production system, adjusting the first formation seepage area according to the change rule to obtain a second formation seepage area, and constructing a seepage area improvement model according to the second formation seepage area and the first formation seepage area;

S103, according to the functional relationship between permeability and rock pore volume multiple, obtaining an equivalent permeability composed of the radial permeability and the vertical permeability, and constructing a permeability improvement model according to the equivalent permeability;

S104: Substitute the seepage area of the second formation, the equivalent permeability and the skin coefficient into the simulated binomial equation to obtain the laminar coefficient and the turbulent coefficient during gas production, and construct a gas production capacity equation according to the laminar coefficient and the turbulent coefficient;

S105 constructs a residual gas production capacity calculation model according to the seepage area improvement model, the permeability improvement model and the gas production capacity equation, and calculates the residual gas production capacity of the horizontal well or vertical well of the gas storage reservoir through the residual gas production capacity calculation model.

In one embodiment of the present invention, the first formation seepage area, radial permeability and vertical permeability are calculated according to the daily gas production pressure and gas production flow rate of the horizontal well or vertical well of the gas storage reservoir when the horizontal well or vertical well is producing gas, including: the first formation seepage area, radial permeability and vertical permeability are calculated by fitting the actual curve with the theoretical plate according to the daily gas production pressure and gas production flow rate of the horizontal well or vertical well of the gas storage reservoir. In the face of the above-mentioned seepage parameters, the current conventional practice is to mainly analyze the dynamic reserves, and it is believed that other parameters are not very certain in the solution process, and the values have a certain range of variation, so the credibility is not great. The present invention has found through a large number of simulations and practices that although a single seepage parameter has a range of variation when solving, after being aggregated, the calculated seepage field does not change much. It is based on this discovery that the present invention uses all the seepage parameters solved by the unstable analysis method to solve the gas production capacity equation.

In the above embodiment, adjusting the first formation seepage area according to the change rule to obtain the second formation seepage area includes:

The seepage area of the second formation is calculated by the following formula:

Area2＝Area1×(Q2×Q1+Q2)÷(Q2×Q1+Q1);

In the above formula, Area2 is the seepage area of the second formation, Area1 is the seepage area of the first formation, Q1 is the current production ratio of the horizontal well or vertical well to the adjacent well of the gas storage, and Q2 is the production ratio of the horizontal well or vertical well to the adjacent well of the gas storage in the preset period. In actual work, it is mainly based on the changes in the subsequent gas production system to establish the change law of the seepage area in the remaining period, and then correct the formation seepage area Area1 obtained in step S101 to obtain the gas production seepage area improvement module. The current production ratio Q1 of the well and the adjacent wells, and the future production ratio Q2 of the well and the adjacent wells change relationship, based on the current seepage area Area1 of the well, calculate the future seepage area Area2 of the well, the method is as follows: Area2 = current seepage area Area1 × (Q2 × Q1 + Q2) ÷ (Q2 × Q1 + Q1).

In one embodiment of the present invention, constructing a permeability improvement model according to the equivalent permeability comprises the following formula:

Kf＝f[(Kk)n,V];

In the above formula, Kf is the equivalent permeability of the horizontal well or vertical well of the gas storage reservoir within the preset period, Kk is the equivalent permeability composed of the radial permeability and the vertical permeability, V is the rock pore volume multiple, and f[(Kk)n, V] is the relationship function obtained by regression of experimental data. Specifically, in actual work, based on the gas-water-water-gas seepage experimental process, the change law of formation permeability in the remaining period can be established, and then the equivalent permeability K composed of the radial permeability Kh and the vertical permeability Kv obtained in step S101 can be corrected to obtain a formation permeability improvement module.

In order to establish the law of gas permeability change, according to the characteristics of gas-water mutual displacement, a gas-water-water-gas displacement experiment was designed to describe the physical process of gas-water mutual displacement in the gas-water interaction zone, and the gas phase relative permeability at the end point of the gas-water interaction zone was obtained:

(Kk)1: Gas phase relative permeability after the first gas-water interaction, describing the remaining relative permeability after the reservoir in the first cycle of the gas storage passes through a gas-water interaction zone causing the seepage capacity to be reduced, and recording the functional relationship between the permeability (Kk)1 and the injected rock pore volume multiple V.

(Kk)2: Gas phase relative permeability after the second gas-water interaction, describing the remaining relative permeability of the gas storage reservoir after the secondary gas-water interaction causes the reduction of seepage capacity in the second cycle, and recording the functional relationship between the permeability (Kk)2 and the injected rock pore volume multiple V.

(Kk)3: Gas phase relative permeability after the third gas-water interaction, describing the remaining relative permeability of the gas storage reservoir after the third period of the reservoir has undergone three gas-water interactions, resulting in a reduction in seepage capacity, and recording the functional relationship between the permeability (Kk)3 and the injected rock pore volume multiple V.

…

(Kk)n: gas phase relative permeability after the nth gas-water interaction displacement, describing the remaining relative permeability of the reservoir after the nth period of the gas storage reservoir has undergone n gas-water interactions, resulting in a reduction in seepage capacity, and recording the functional relationship between the permeability (Kk)n and the injected rock pore volume multiple V.

Finally, the Kf method in the future gas production process is obtained as follows: Kf = f[(Kk)n, V], where the function f[(Kk)n, V] is generally regressed into a polynomial based on experimental data. Then, the equivalent permeability K composed of the radial permeability Kh and the vertical permeability Kv obtained in step S101 is corrected to obtain a formation permeability improvement module. Of course, in actual work, relevant technicians in this field can also choose a suitable method to adjust the above process according to actual needs, and the present invention is not further limited here.

In one embodiment of the present invention, substituting the second formation seepage area, the equivalent permeability and the skin coefficient into the simulated binomial equation to obtain the laminar coefficient and the turbulent coefficient during gas production comprises:

The improved formation seepage area Area2 in step S102 and the improved effective permeability Kf in step S103, together with the skin coefficient in step S101 and the actual detected formation thickness and other parameters, are substituted into the following formulas and solved to obtain the values of the laminar coefficient A and the turbulent coefficient B:

When the target well is a horizontal well, the laminar flow coefficient and turbulent flow coefficient are calculated by the following formula:

Area2＝3.14159×R_eh×H_ehβ＝7.644×10¹⁰/K^1.2；

Area2＝3.14159×R _eh ×H _eh β＝7.644×10 ¹⁰ /K ^1.2 ;

When the target well is a vertical well, the laminar flow coefficient and turbulent flow coefficient are calculated by the following formula:

为平均粘度；

为气体平均压缩因子；T为储气库地层温度；K为储气地层拟化渗透率；h为地层厚度；L为水平段长度；r_w为井眼半径；K_v为地层垂向渗透率；K_h为地层水平方向渗透率；r_g为气体相对密度；r_e为地层泄压半径。In the above formula, A is the laminar coefficient of the horizontal well; B is the turbulent coefficient of the horizontal well;

is the average viscosity;

is the average gas compression factor; T is the gas storage reservoir formation temperature; K is the simulated permeability of the gas storage formation; h is the formation thickness; L is the horizontal section length; _rw is the wellbore radius; _Kv is the vertical permeability of the formation; _Kh is the horizontal permeability of the formation; _rg is the relative density of gas; _{and re} is the formation pressure relief radius.

Afterwards, the values of the laminar coefficient A and the turbulent coefficient B are respectively substituted into the typical binomial equation, and then the gas production capacity equation of the well in the future that fully considers the changes in the flow supply area and permeability is obtained, that is, the gas production capacity calculation model:

_Pe2 ^- _Pwf2 =AQ ^{+ BQ2} ;

In the above formula, _Pe is the average formation pressure; _Pwf is the bottom hole flowing pressure; A is the laminar flow coefficient of the gas well; B is the turbulent flow coefficient of the gas well; Q is the daily gas production of the gas well.

Therefore, when obtaining the remaining gas production capacity of a horizontal well or vertical well in the current cycle, the present invention does not directly take the well test value like the current method, but obtains the actual formation seepage range during gas production, and fully considers the changing law of rock permeability in the future gas production process, substitutes these improved parameters into the classic binomial equation, and then obtains the subsequent remaining gas production capacity equation. Taking a gas storage facility in my country as an example, the well test method has been used to obtain a horizontal well or vertical well gas production capacity of 1.1 million cubic meters per day for nearly 6 years, and the injection has always been made according to this value. However, the gas production capacity is calculated as 1.7 million cubic meters per day using the present invention, and the actual injection production is carried out according to this, without any abnormality, and the gas production task of the well is quickly achieved, which proves that the prediction method provided by the present invention is relatively reliable. At present, the methods for obtaining the gas production capacity of horizontal wells or vertical wells in gas storage reservoirs mostly come from well test interpretation. Because this method needs to disturb the normal gas production of the gas storage reservoir during testing, and needs to pay a large amount of instrument testing and interpretation fees, the test results are not considered in principle. The actual situation of the seepage range and reservoir physical properties of the gas storage reservoir causes a large difference from the actual level of the well. Taking a gas storage reservoir in my country as an example, the well test method has obtained a horizontal well or vertical well gas production capacity of 1.1 million cubic meters/day in the past six years. Based on this value, the injection has always been made according to this value. However, the gas production capacity is calculated as 1.7 million cubic meters/day using the present invention. Based on this, the actual injection production has no abnormality and the gas production task of the well is quickly achieved, which proves that the prediction method provided by the present invention is relatively reliable.

Please refer to FIG. 2 , the present invention also provides a device for calculating the remaining gas production capacity, the device comprising an analysis module, an improvement module, a construction module and a calculation module; the analysis module is used to calculate the first formation seepage area, radial permeability, vertical permeability and skin coefficient when the horizontal well or vertical well is producing gas according to the daily gas production pressure and gas production flow rate of the horizontal well or vertical well of the gas storage reservoir; the improvement module is used to calculate the change law of the seepage area within a preset period according to the change of the gas production system, adjust the first formation seepage area according to the change law to obtain the second formation seepage area, and construct a seepage area improvement model according to the second formation seepage area and the first formation seepage area; and The functional relationship between the permeability and the rock pore volume multiple is obtained to obtain the equivalent permeability composed of the radial permeability and the vertical permeability, and a permeability improvement model is constructed according to the equivalent permeability; the construction module is used to bring the seepage area of the second formation, the equivalent permeability and the skin coefficient into the simulated binomial equation to obtain the laminar coefficient and the turbulent coefficient during gas production, and a gas production capacity equation is constructed according to the laminar coefficient and the turbulent coefficient; the calculation module is used to construct a residual gas production capacity calculation model according to the seepage area improvement model, the permeability improvement model and the gas production capacity equation, and the residual gas production capacity of the horizontal well or vertical well of the gas storage reservoir is calculated by the residual gas production capacity calculation model.

In the above embodiment, the improvement module further comprises: obtaining the seepage area, radial permeability and vertical permeability of the first formation by fitting the actual curve with the theoretical chart according to the daily gas production pressure and gas production flow rate of the horizontal well or vertical well of the gas reservoir. The improvement module obtains the seepage area of the second formation by calculating the following formula:

Area2＝Area1×(Q2×Q1+Q2)÷(Q2×Q1+Q1);

In the above formula, Area2 is the seepage area of the second formation, Area1 is the seepage area of the first formation, Q1 is the production ratio of the current horizontal well or vertical well to the adjacent wells in the gas storage reservoir, and Q2 is the production ratio of the horizontal well or vertical well to the adjacent wells in the gas storage reservoir within the preset period.

In one embodiment of the present invention, the building module calculates the laminar coefficient and the turbulent coefficient using the following formula:

When the target well is a horizontal well, the laminar flow coefficient and turbulent flow coefficient are calculated by the following formula:

Area2＝3.14159×R_eh×R_ehβ＝7.644×10¹⁰/K^1.2；

Area2＝3.14159×R _eh ×R _eh β＝7.644×10 ¹⁰ /K ^1.2 ;

When the target well is a vertical well, the laminar flow coefficient and turbulent flow coefficient are calculated by the following formula:

为平均粘度；

为气体平均压缩因子；T为储气库地层温度；K为储气地层拟化渗透率；h为地层厚度；L为水平段长度；r_w为井眼半径；K_v为地层垂向渗透率；K_h为地层水平方向渗透率；r_g为气体相对密度；r_e为地层泄压半径。In the above formula, A is the laminar coefficient of the horizontal well; B is the turbulent coefficient of the horizontal well;

is the average viscosity;

is the average gas compression factor; T is the gas storage reservoir formation temperature; K is the simulated permeability of the gas storage formation; h is the formation thickness; L is the horizontal section length; _rw is the wellbore radius; _Kv is the vertical permeability of the formation; _Kh is the horizontal permeability of the formation; _rg is the relative density of gas; _{and re} is the formation pressure relief radius.

The present invention fully considers the seepage range and the change law of formation permeability during gas production in the gas storage, and the accuracy of its calculation results is greatly improved, showing strong technical advantages. In addition, compared with conventional well testing, which requires interrupting the gas production of the gas storage to test the instrument, the data required by the present invention is only the daily gas production data, which does not need to delay the precious gas production time of the gas storage, and does not need to pay the instrument testing fee, etc., so it shows a relatively obvious economic advantage; at the same time, it will provide more accurate remaining gas production capacity for the gas storage currently in operation, and thus provide a scientific basis for accurately predicting the overall gas production capacity of the gas storage in summer.

The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above method when executing the computer program.

The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program for executing the above method.

As shown in FIG3 , the electronic device 600 may further include: a communication module 110, an input unit 120, an audio processing unit 130, a display 160, and a power supply 170. It is worth noting that the electronic device 600 does not necessarily include all the components shown in FIG3 ; in addition, the electronic device 600 may also include components not shown in FIG3 , and reference may be made to the prior art.

As shown in FIG. 3 , the central processor 100 is sometimes also referred to as a controller or an operation control, and may include a microprocessor or other processor devices and/or logic devices. The central processor 100 receives inputs and controls the operations of various components of the electronic device 600 .

The memory 140 may be, for example, one or more of a cache, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory or other suitable devices. The above-mentioned information related to the failure may be stored, and a program for executing the relevant information may also be stored. The CPU 100 may execute the program stored in the memory 140 to implement information storage or processing.

The input unit 120 provides input to the CPU 100. The input unit 120 is, for example, a key or a touch input device. The power supply 170 is used to provide power to the electronic device 600. The display 160 is used to display display objects such as images and text. The display may be, for example, an LCD display, but is not limited thereto.

The memory 140 may be a solid-state memory, such as a read-only memory (ROM), a random access memory (RAM), a SIM card, etc. It may also be a memory that saves information even when the power is off, can be selectively erased, and is provided with more data, examples of which are sometimes referred to as EPROMs, etc. The memory 140 may also be some other type of device. The memory 140 includes a buffer memory 141 (sometimes referred to as a buffer). The memory 140 may include an application/function storage unit 142, which is used to store application programs and function programs or processes for executing the operation of the electronic device 600 through the central processor 100.

The memory 140 may also include a data storage unit 143 for storing data, such as contacts, digital data, pictures, sounds, and/or any other data used by the electronic device. The driver storage unit 144 of the memory 140 may include various drivers for communication functions of the electronic device and/or for executing other functions of the electronic device (such as messaging applications, address book applications, etc.).

The communication module 110 is a transmitter/receiver 110 that transmits and receives signals via an antenna 111. The communication module (transmitter/receiver) 110 is coupled to the central processor 100 to provide input signals and receive output signals, which may be the same as the case of a conventional mobile communication terminal.

Based on different communication technologies, multiple communication modules 110 may be provided in the same electronic device, such as a cellular network module, a Bluetooth module and/or a wireless LAN module. The communication module (transmitter/receiver) 110 is also coupled to a speaker 131 and a microphone 132 via an audio processor 130 to provide an audio output via the speaker 131 and receive an audio input from the microphone 132, thereby realizing a common telecommunication function. The audio processor 130 may include any suitable buffer, decoder, amplifier, etc. In addition, the audio processor 130 is also coupled to the central processor 100, so that recording can be performed on the local machine through the microphone 132, and the sound stored on the local machine can be played through the speaker 131.

Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented 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.

The present invention is described with reference to the flowchart and/or block diagram of the method, device (system), and computer program product according to the embodiment of the present invention. It should be understood that each process and/or box in the flowchart and/or block diagram, as well as the combination of the process and/or box in the flowchart and/or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is 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 in the scope of protection of the present invention.

Claims (12)

1. A method for calculating residual gas production capacity, the method comprising:

calculating and obtaining a first stratum seepage area, a radial permeability, a vertical permeability and a skin coefficient when the horizontal well or the vertical well adopts gas according to the daily gas production pressure and the gas production flow of the horizontal well or the vertical well of the gas storage;

calculating a change rule of the seepage area in a preset period according to the change condition of the gas production system, adjusting the first stratum seepage area according to the change rule to obtain a second stratum seepage area, and constructing a seepage area improvement model according to the second stratum seepage area and the first stratum seepage area;

obtaining equivalent permeability composed of the radial permeability and the vertical permeability according to a functional relation between the permeability and the rock pore volume multiple, and constructing a permeability improvement model according to the equivalent permeability;

substituting the second stratum seepage area, the equivalent permeability and the skin coefficient into a fitting binomial equation to obtain a laminar flow coefficient and a turbulent flow coefficient during gas production, and constructing a gas production capacity equation according to the laminar flow coefficient and the turbulent flow coefficient;

and constructing a residual gas production capacity calculation model according to the seepage area improvement model, the permeability improvement model and the gas production capacity equation, and calculating the residual gas production capacity of the horizontal well or the vertical well of the gas storage through the residual gas production capacity calculation model.

2. The method for calculating the residual gas production capacity according to claim 1, wherein calculating the first formation seepage area, the radial permeability and the vertical permeability when gas is produced in the horizontal well or the vertical well according to the daily gas production pressure and the gas production flow of the horizontal well or the vertical well of the gas storage comprises: and calculating by fitting an actual curve and a theoretical plate according to the daily gas production pressure and the gas production flow of a horizontal well or a vertical well of the gas reservoir to obtain the first formation seepage area, the radial permeability and the vertical permeability.

3. The method for calculating the remaining gas production capacity according to claim 1, wherein the step of adjusting the first formation seepage area according to the change rule to obtain a second formation seepage area comprises:

and calculating to obtain the second stratum seepage area by the following formula:

Area2＝Area1×(Q2×Q1+Q2)÷(Q2×Q1+Q1)；

in the above formula, area2 is the second formation seepage Area, area1 is the first formation seepage Area, Q1 is the current gas storage horizontal well or vertical well to adjacent well production ratio, and Q2 is the gas storage horizontal well or vertical well to adjacent well production ratio within the preset period.

4. The method for calculating residual gas production capacity according to claim 1, wherein the construction of a permeability improvement model according to the equivalent permeability comprises the following formula:

Kf＝f[(Kk)n,V]；

in the above formula, kf is the equivalent permeability of a horizontal well or a vertical well of the gas reservoir in a preset period, kk is the equivalent permeability composed of the radial permeability and the vertical permeability, V is the rock pore volume multiple, and f [ (Kk) n, V ] is a relation function obtained by experimental data regression.

5. The method for calculating the residual gas production capacity according to claim 1, wherein the step of substituting the second formation seepage area, the equivalent permeability and the skin coefficient into a fitting binomial equation to obtain a laminar flow coefficient and a turbulent flow coefficient during gas production comprises the steps of:

when the target well is a horizontal well, calculating and obtaining a laminar flow coefficient and a turbulent flow coefficient through the following formulas:

Area2＝3.14159×R _eh ×R _eh β＝7.644×10 ¹⁰ /K ^1.2 ；

when the target well is a vertical well, the laminar flow coefficient and the turbulent flow coefficient are obtained by the following formula:

in the above formula, a is the laminar flow coefficient of the horizontal well; b is the turbulence factor of the horizontal well;

is the average viscosity;

Is the gas average compression factor; t is the formation temperature of the gas storage; k is the gas storage formation simulated permeability; h is the formation thickness; l is the length of the horizontal segment; r is _w Is the borehole radius; k _v Is the formation vertical permeability; k _h Is the horizontal permeability of the stratum; r is _g Is the relative density of the gas; r is _e Relieving the formation of a pressure radius.

6. The method for calculating the residual gas production capacity according to claim 1, wherein the gas production capacity calculation model is the following formula:

P _e ² -P _wf ² ＝AQ+BQ ² ；

in the above formula, P _e Is the formation mean pressure; p _wf Bottom hole flow pressure; a is the gas well laminar flow coefficient; b is the gas well turbulence coefficient; q is the daily gas production rate of the gas well.

7. The device for calculating the residual gas production capacity is characterized by comprising an analysis module, an improvement module, a construction module and a calculation module;

the analysis module is used for calculating and obtaining a first stratum seepage area, a radial permeability, a vertical permeability and a skin coefficient when the gas is produced in the horizontal well or the vertical well according to the daily gas production pressure and the gas production flow of the horizontal well or the vertical well of the gas storage;

the improvement module is used for calculating a change rule of the seepage area in a preset period according to the change condition of the gas production system, adjusting the first stratum seepage area according to the change rule to obtain a second stratum seepage area, and constructing a seepage area improvement model according to the second stratum seepage area and the first stratum seepage area; obtaining equivalent permeability composed of the radial permeability and the vertical permeability according to a functional relation between the permeability and the rock pore volume multiple, and constructing a permeability improvement model according to the equivalent permeability;

the construction module is used for substituting the second stratum seepage area, the equivalent permeability and the skin coefficient into a fitting binomial equation to obtain a laminar flow coefficient and a turbulent flow coefficient during gas production, and constructing a gas production capacity equation according to the laminar flow coefficient and the turbulent flow coefficient;

the calculation module is used for constructing a residual gas production capacity calculation model according to the seepage area improvement model, the permeability improvement model and the gas production capacity equation, and calculating the residual gas production capacity of the horizontal well or the vertical well of the gas storage through the residual gas production capacity calculation model.

8. The residual gas production capacity calculation device according to claim 7, wherein the improvement module further comprises: and according to the daily gas production pressure and the gas production flow of a horizontal well or a vertical well of the gas reservoir, calculating by fitting an actual curve and a theoretical plate to obtain the first formation seepage area, the radial permeability and the vertical permeability.

9. The residual gas production capacity calculation device according to claim 7, wherein the improvement module further comprises:

and calculating to obtain the second stratum seepage area by the following formula:

Area2＝Area1×(Q2×Q1+Q2)÷(Q2×Q1+Q1)；

in the above formula, area2 is the second formation seepage Area, area1 is the first formation seepage Area, Q1 is the current gas storage horizontal well or vertical well to adjacent well production ratio, and Q2 is the gas storage horizontal well or vertical well to adjacent well production ratio within the preset period.

10. The residual gas production capacity calculation device according to claim 7, wherein the construction module comprises:

when the target well is a horizontal well, the laminar flow coefficient and the turbulent flow coefficient are obtained by calculating according to the following formulas:

Area2＝3.14159×R _eh ×R _eh β＝7.644×10 ¹⁰ /K ^1.2 ；

when the target well is a vertical well, the laminar flow coefficient and the turbulent flow coefficient are obtained by the following formula:

in the above formula, a is the laminar flow coefficient of the horizontal well; b is the turbulence factor of the horizontal well;

is the average viscosity;

Is a gas flatA voltage scaling factor; t is the formation temperature of the gas storage; k is the gas storage stratum simulated permeability; h is the formation thickness; l is the length of the horizontal segment; r is _w Is the borehole radius; k _v Is the formation vertical permeability; k _h Is the horizontal permeability of the stratum; r is _g Is the relative density of the gas; r is _e Relieving the formation of a pressure radius.

11. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method of any of claims 1 to 6 when executing the computer program.

12. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program for executing the method of any one of claims 1 to 6.

Images