A method for back-calculating dynamic reserves of hydrocarbon-bearing height in finite closed massive oil and gas reservoirs

Abstract

The present invention belongs to the field of oil and gas field development and reservoir engineering technology, and specifically relates to a dynamic reserve back-calculation method for the hydrocarbon height of a limited closed block oil and gas reservoir. In order to overcome the problems in the prior art, the present invention provides a dynamic reserve back-calculation method for the hydrocarbon height of a limited closed block oil and gas reservoir, which obtains the production dynamic data of the target well; uses the monthly wellhead pressure data and calculates the bottom hole flow pressure and formation pressure through the pressure gradient; selects the material balance equation according to the type of the target well, and then obtains the dynamic reserves of the target well through the material balance equation; through geological data and drilling and completion data, selects different forms of leakage fluid models according to the well layout of the target well to perform dynamic reserve back-calculation of the hydrocarbon height. The present invention can simply and conveniently calculate the hydrocarbon height through production dynamic data, and the calculation results are accurate and reliable, successfully overcoming the limitations of static description methods, and has important guiding significance for the rational development and production management of fault block oil reservoirs.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field development and reservoir engineering, and in particular relates to a dynamic reserve back-calculation method for hydrocarbon-containing height of a limited closed block oil and gas reservoir. Background Art

[0002] With the development of the petroleum industry, block oil reservoirs have become one of the most important oil and gas exploration areas in the world. In recent years, large fault block oil and gas fields have been discovered in the Tarim Basin and the Ordos Basin in my country. The proportion of this type of oil and gas reservoirs in the country's oil and gas resources has continued to increase, and the development potential has gradually increased. It is a key area for future oil and gas reserve increase. How to reasonably and effectively develop this type of oil reservoir has become a difficult problem that needs to be solved urgently in the oil field.

[0003] There are a large number of strike-slip fault blocks in the fault-block oil and gas reservoirs in western my country, which have been transformed by multiple phases of karstification to form fracture-cavity reservoirs. Many fracture-cavity reservoirs are independent, limited, and closed oil and gas storage units. The reservoir types of fracture-cavity reservoirs are mainly large-scale karst caves, supplemented by fractures and holes. They are distributed in blocks along large fault blocks and have discontinuous characteristics. The reservoir plane is strip-shaped along the fault blocks and plate-shaped along the fault blocks. The internal heterogeneity of fault-block oil reservoirs is extremely strong, and due to engineering factors such as venting and leakage, drilling cannot achieve drilling through the bottom of the reservoir to obtain the true hydrocarbon-bearing height.

[0004] The hydrocarbon height refers to the vertical distance from the bottom of the oil and gas reservoir to the top of the oil and gas reservoir of effective hydrocarbons. The size of the hydrocarbon height is a crucial parameter for judging the size of the oil and gas reservoir, oil and gas reservoir research, and production management. At present, the industry usually uses static seismic carving description methods to determine the hydrocarbon height, but this type of static method is often not accurate and the results are inaccurate. There are few studies on the dynamic calculation method of the hydrocarbon height of limited closed block oil reservoirs. Therefore, the present invention innovates a calculation method for the hydrocarbon height of limited closed block oil and gas reservoirs by back-calculating dynamic reserves. The hydrocarbon height can be simply and conveniently calculated through production dynamic data. The calculation results are accurate and reliable, successfully overcoming the limitations of static description methods, and have important guiding significance for the rational development and production management of fault block oil reservoirs. Summary of the invention

[0005] In order to overcome the problems in the prior art, the present invention provides a method for back-calculating the dynamic reserves of hydrocarbon-containing height in a finite closed block oil and gas reservoir, which solves the technical problem that the conventional static description means have low accuracy.

[0006] The technical solution provided by the present invention to solve the above technical problems is: a method for back-calculating the dynamic reserves of hydrocarbon-containing height of a limited closed block oil and gas reservoir, comprising the following steps:

[0007] Step S10, obtaining the production dynamic data of the target well, and obtaining the monthly wellhead pressure data according to the production dynamic data;

[0008] Step S20, using the monthly wellhead pressure data and the pressure gradient to calculate the bottom hole flow pressure and formation pressure;

[0009] Step S30, selecting a material balance equation according to the type of the target well, and then obtaining the dynamic reserves of the target well through the material balance equation;

[0010] Step S40: Using geological data and drilling and completion data, different forms of drainage fluid models are selected according to the well layout of the target wells to perform dynamic reserve back calculation of hydrocarbon-bearing height.

[0011] A further technical solution is that the specific process of step S20 is:

[0012] Step S201, selecting the wellhead pressure data of each month, and obtaining the bottom hole flowing pressure by using the known pressure gradient;

[0013] Step S202, performing linear regression on the bottom hole flow pressure, and fitting to obtain a bottom hole flow pressure straight line;

[0014] Step S203: Calculate the formation pressure line using the bottom hole flow pressure line, so that all formation pressure values ​​are greater than the maximum value of the bottom hole flow pressure.

[0015] A further technical solution is that, in step S30, when the target well is an oil well, the following closed unsaturated reservoir material balance equation is selected:

[0016] NB oi C t Δp=N p B o +N w B w

[0017]

[0018] Where: N-dynamic reserves, m 3 ; B oi - Volume coefficient of crude oil under original conditions, dimensionless; C t -Total compressibility of the reservoir, 1 / MPa; N p -Cumulative oil production, m 3 ; N w -Cumulative water production, m 3 ; B o -Crude oil volume coefficient, dimensionless; B w -Water volume coefficient, dimensionless; C o -Compression coefficient of crude oil, 1 / MPa; C w - Water compressibility, 1 / MPa; Swi -Immobile water saturation, dimensionless; C f - rock compression coefficient, 1 / MPa; Δp-pressure difference, MPa;

[0019] When the target well is a gas well, the following constant volume gas reservoir material balance equation is selected:

[0020] GB gi =(NG p )B g

[0021] Where: N-dynamic reserves, m 3 ; B gi - Gas volume coefficient under original conditions; G p -Cumulative gas production, m 3 ; B g -Volume coefficient of the gas at the current pressure.

[0022] A further technical solution is that, in step S30, when the target well is an oil well, the specific calculation process of the dynamic reserves of the target well is:

[0023] Step S31, let the horizontal coordinate X = △p, the vertical coordinate Y = N p B o +N w B w , draw the reservoir material balance straight line, then the closed unsaturated material balance equation becomes:

[0024] Y=NB oi C t X

[0025] Where: N-dynamic reserves, m 3 ; B oi - Volume coefficient of crude oil under original conditions, dimensionless; C t -Total reservoir compressibility, 1 / MPa;

[0026] Step S32: Draw a material balance analysis curve using relevant data. The curve is a straight line passing through the origin. A linear equation can be obtained from the data points on the straight line, and the slope α of the straight line can be obtained:

[0027] Y=αX

[0028] Where: α-slope of the straight line, m 3 / MPa;

[0029] Step S33, the dynamic geological reserve N of the oil reservoir can be obtained by the slope of the linear equation;

[0030]

[0031] Where: Boi - Volume coefficient of crude oil under original conditions, dimensionless; C t -Total compressibility of the reservoir, 1 / MPa; N-dynamic reserves, m 3 .

[0032] A further technical solution is that, in step S30, when the target well is a gas well, the specific calculation process of the dynamic reserves of the target well is:

[0033] Step S301: Substitute the material balance equation according to the definition of the gas volume coefficient and rewrite the material balance equation as follows:

[0034]

[0035] Where: p-current pressure, MPa; p i -Original pressure, MPa; Z-Deviation coefficient at current pressure, dimensionless; Z i - coefficient of deviation under original conditions, dimensionless;

[0036] Step S302, using relevant data to draw a material balance analysis line, with the ordinate axis being the formation pressure coefficient and the abscissa axis being the cumulative gas production, and the line being extrapolated to p / Z=0 to obtain the dynamic reserve G;

[0037] N=G p

[0038] Where: G p -Cumulative gas production, m 3 ; N-dynamic reserves, m 3 .

[0039] A further technical solution is that, in step S40, if the target well is drilled on a large fault block, a rectangular parallelepiped drainage model distributed along the large fault block is selected to perform dynamic reserve backcalculation of drainage body volume; the rectangular parallelepiped drainage model is controlled by the drainage length L, the drainage width B and the hydrocarbon-bearing height H, and the hydrocarbon-bearing height H is obtained by substituting the well test interpretation data into relevant data;

[0040] If the target well is drilled on a small fault block, the cylindrical drainage model is used to backcalculate the drainage fluid volume from the dynamic reserves. The cylindrical drainage model is controlled by the drainage radius R and the hydrocarbon-bearing height H. The hydrocarbon-bearing height H is obtained by substituting the well test interpretation data into relevant data.

[0041] A further technical solution is that, in step S40, if the target well is drilled on a large fault block, the calculation formula for its hydrocarbon-containing height is as follows:

[0042]

[0043] Where: N-dynamic reserves, m 3 ;φ-reservoir porosity; Swi -Immobilized water saturation.

[0044] A further technical solution is that, in step S40, if the target well is drilled on a small fault block, the calculation formula for its hydrocarbon-bearing height is as follows:

[0045]

[0046] Where: N-dynamic reserves, m 3 ;φ-reservoir porosity; S wi -Immobilized water saturation.

[0047] The present invention has the following beneficial effects: based on the material balance principle, the present invention determines a calculation method for the hydrocarbon content height suitable for limited closed block oil and gas reservoirs. Not only can the hydrocarbon content height of the oil and gas reservoir be conveniently and quickly calculated through production dynamic data, but also the scale of such complex oil reservoirs as limited closed block oil reservoirs can be effectively determined, thus providing a reliable basis for the efficient development of such oil reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a straight line diagram of material balance of unsaturated oil reservoir;

[0049] Figure 2 It is a straight line diagram of material balance of gas reservoir;

[0050] Figure 3 It is a schematic diagram of the rectangular leakage model;

[0051] Figure 4 It is a schematic diagram of the cylindrical leakage model;

[0052] Figure 5 It is a straight line graph of bottom hole flowing pressure and formation pressure of Y-3 oil well;

[0053] Figure 6 It is the material balance straight line diagram of Y-3 oil well. DETAILED DESCRIPTION

[0054] The present invention is further described in detail below in conjunction with the embodiments and drawings.

[0055] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0056] The technical scheme of the dynamic reserve back-calculation method of the hydrocarbon-containing height of a limited closed block oil and gas reservoir of the present invention is: collecting the production dynamic data and well test interpretation data of a certain oil (gas) well in the limited closed block oil and gas reservoir, and obtaining the monthly wellhead flow pressure, cumulative water production, cumulative oil production, cumulative gas production, volume coefficient and other production dynamic data of the oil (gas) well; drawing the wellhead flow pressure dynamic curve with the production dynamic data; calculating the bottom hole flow pressure and formation pressure through the wellhead flow pressure curve; selecting the material balance equation according to the type of the oil and gas well; and obtaining the dynamic reserve of the oil (gas) well through the material balance line; finally, according to the geological and drilling and completion data, for the oil (gas) well drilled on the large fault block, selecting the rectangular parallelepiped fracture-hole unit body leakage model to back-calculate the hydrocarbon-containing height; for the oil (gas) well drilled on the small fault block, selecting the cylindrical fracture-hole unit body leakage model to back-calculate the hydrocarbon-containing height; specifically comprising the following steps:

[0057] Step S10, collecting production performance data, PVT data and well test interpretation data of an oil (gas) well in a limited closed block oil and gas reservoir, obtaining relevant basic production data, and obtaining monthly production performance data of the oil (gas) well, as shown in Table 1;

[0058] Table 1 Sample table of production performance data of an oil and gas well in a limited closed block reservoir

[0059]

[0060]

[0061] Step S20, using the monthly wellhead pressure data obtained from the production dynamic data, calculate the bottom hole flowing pressure and formation pressure through the pressure gradient;

[0062] Step S201, selecting the wellhead pressure data of each month, and obtaining the bottom hole flowing pressure by using the known pressure gradient;

[0063] Step S202, performing linear regression on the bottom hole flow pressure, and fitting to obtain a bottom hole flow pressure straight line;

[0064] Step S203, using the bottom hole flow pressure line to calculate the formation pressure line, so that all formation pressure values ​​are greater than the maximum value of the bottom hole flow pressure;

[0065] Step S30, using the obtained bottom hole flowing pressure and formation pressure to make a difference, obtain the pressure difference Δp, and sort out the wellhead pressure, bottom hole flowing pressure, formation pressure and pressure difference data table of the oil and gas well, as shown in Table 2;

[0066] Table 2 Sample table of pressure calculation data of an oil and gas well in a limited closed block reservoir

[0067]

[0068] Step S40: Obtain the cumulative oil production, gas production, and water production of each well through the monthly production data table of oil (gas) wells, and convert the units to 10. 4 m 3 , as shown in Table 3;

[0069] Table 3 Sample data for material balance calculation of a block oil reservoir well

[0070]

[0071]

[0072] Step S50: According to the production dynamic data and the type of oil and gas wells, different material balance equations are selected, and then the dynamic reserves of the target well are obtained through the material balance equation;

[0073] If the well is an oil well, the relevant data obtained in the above steps (volume coefficient, compressibility coefficient, cumulative water production, cumulative oil production, cumulative gas production) are sorted into a table and substituted into the material balance equation of the closed unsaturated oil reservoir;

[0074] NB oi C t Δp=N p B o +N w B w

[0075]

[0076] Where: N-dynamic reserves, m 3 ; B oi - Volume coefficient of crude oil under original conditions, dimensionless; C t -Total reservoir compressibility, 1 / MPa; N p -Cumulative oil production, m 3 ; N w -Cumulative water production, m 3 ; B o -Crude oil volume coefficient, dimensionless; Bw -Water volume coefficient, dimensionless; C o -Compression coefficient of crude oil, 1 / MPa; C w - Water compressibility, 1 / MPa; S wi -Immobile water saturation, dimensionless; C f - rock compression coefficient, 1 / MPa;

[0077] Let the horizontal coordinate X = △p, the vertical coordinate Y = N p B o +N w B w , draw the reservoir material balance straight line, then the closed unsaturated material balance equation becomes:

[0078] Y=NB oi C t X

[0079] Use relevant data to draw a material balance analysis curve, which is a straight line passing through the origin, such as Figure 1 As shown, the linear equation can be obtained from the data points on the straight line, and the slope α of the straight line can be obtained:

[0080] Y=αX

[0081] Where: α-slope of the straight line, m 3 / MPa;

[0082] The dynamic geological reserves N of the reservoir can be obtained through the slope of the linear equation;

[0083]

[0084] Where: B oi - Volume coefficient of crude oil under original conditions, dimensionless; C t -Total compressibility of the reservoir, 1 / MPa; N-dynamic reserves, m 3 ;

[0085] If the well is a gas well, the relevant data (volume coefficient, formation pressure coefficient, cumulative gas production) obtained in the above steps are sorted into a table and substituted into the material balance equation of the constant volume gas reservoir;

[0086] GB gi =(GG p )B g

[0087] In the formula, G is dynamic reserve, m is 3 ; B gi - Gas volume coefficient under original conditions; G p -Cumulative gas production, m 3 ; B g -Volume coefficient of the gas at the current pressure.

[0088] Substitute the material balance equation according to the definition of gas volume coefficient and rewrite it as follows:

[0089]

[0090] Where, p-current pressure, MPa; p i -Original pressure, MPa; Z-Deviation coefficient at current pressure, dimensionless; Z i - Coefficient of deviation under original conditions, dimensionless.

[0091] Use the relevant data to draw a material balance analysis line, such as Figure 2 As shown, the ordinate axis is the formation pressure coefficient, and the abscissa axis is the cumulative gas production. Extrapolating the straight line to p / Z = 0, the dynamic reserves G of the gas well can be obtained;

[0092] G=G p

[0093] Step S60, using geological data and drilling and completion data, and according to the well layout of oil (gas) wells, different forms of drainage fluid models are selected to perform dynamic reserve back calculation of hydrocarbon height H;

[0094] If the oil (gas) well is drilled on a large fault block, the rectangular drainage model distributed along the large fault block is used to back-calculate the drainage volume from the dynamic reserves; Figure 3 As shown in the figure, the rectangular parallelepiped leakage model is controlled by the leakage length L, the leakage width B and the hydrocarbon-bearing height H. The hydrocarbon-bearing height H is obtained by substituting the well test interpretation data into relevant data (for wells without well test interpretation data, half of the distance to the adjacent well can be taken as the leakage length L, and the leakage width B can be represented by the width of the seismic carving spread);

[0095]

[0096] Where: N-dynamic reserves, m 3 ;φ-reservoir porosity; S wi - bound water saturation;

[0097] If the oil (gas) well is drilled on a small fault block, the cylindrical drainage model is used to back-calculate the drainage volume from the dynamic reserves, such as Figure 4 As shown in the figure, the cylindrical leakage model is controlled by the leakage radius R and the hydrocarbon-containing height H. The hydrocarbon-containing height H is obtained by substituting the well test interpretation data into relevant data (for wells without well test interpretation data, half of the straight-line distance to the adjacent well can be taken as the leakage radius);

[0098]

[0099] Where: N-dynamic reserves, m 3 ;φ-reservoir porosity; Swi -Immobilized water saturation.

[0100] Example

[0101] The present invention takes the limited closed block reservoir Y-3 oil well as an example, and comprises the following steps:

[0102] Step S10, collecting the production dynamic data of the limited closed block reservoir Y-3 oil well, obtaining relevant production data, and obtaining the monthly production dynamic table of the oil well, as shown in Table 4;

[0103] Table 4 Monthly production dynamic data of Y-3 oil well

[0104]

[0105]

[0106] Step S20, using the monthly wellhead oil pressure data obtained from the production dynamic table, calculate the corresponding bottom hole flow pressure and formation pressure for each month through the pressure gradient;

[0107] Step S201, select the wellhead pressure data of each month, obtain the pressure gradient of 0.0057MPa / m through the pressure test data, and obtain the corresponding bottom hole flowing pressure of each month through the wellhead oil pressure;

[0108] Step S202, performing linear regression on the calculated bottom hole flow pressure, and drawing a bottom hole flow pressure straight line;

[0109] Step S203: Calculate the formation pressure line using the bottom hole flow pressure line, such as Figure 5 As shown, the formation pressure is all greater than the maximum bottom hole flow pressure. The points on the straight line are the formation pressures corresponding to the oil wells every month.

[0110] Step S30, using the obtained bottom hole flow pressure and formation pressure to make a difference, obtain the pressure difference, and sort out the data table of wellhead oil pressure, bottom hole flow pressure, formation pressure and pressure difference of Y-3 oil well, as shown in Table 5;

[0111] Table 5 Y-3 oil well pressure calculation data table

[0112]

[0113] Step S40: The material balance calculation preparation data such as the cumulative oil production, cumulative water production and volume coefficient of the Y-3 oil well are obtained through the monthly production data table of the Y-3 oil well and the calculated pressure data table, and the units are uniformly converted to 10. 4 m 3 , as shown in Table 6;

[0114] Table 6 Y-3 Oil Well Material Balance Calculation Preparation Data Table

[0115]

[0116] Step S50: According to the production dynamic data of the Y-3 oil well, the Y-3 well is an oil well, so the reservoir material balance equation is selected, and the relevant data (volume coefficient, compressibility coefficient, cumulative water production, cumulative oil production, etc.) obtained in the above steps are substituted into the reservoir unsaturated material balance equation;

[0117] NB oi C t Δp=N p B o +N w B w

[0118]

[0119] Step S60, set the vertical axis to be Y=N p B o +N w B w , the horizontal axis is X = Δp, and the reservoir material balance line is drawn. Then the closed unsaturated material balance equation becomes:

[0120] Y=NB oi C t X

[0121] Step S70: Substitute relevant data to draw a material balance analysis curve, such as Figure 6 As shown, the curve is a straight line passing through the origin. The linear equation can be obtained from the data points on the straight line, and the slope α of the straight line can be obtained;

[0122] α=0.68

[0123] Step S80, obtaining the dynamic geological reserves N of the Y-3 oil well through the slope of the straight line;

[0124]

[0125] Step S90, according to geological data and completed drilling data, the Y-3 oil well is drilled on the Y large fault block, so the rectangular parallelepiped drainage model distributed along the large fault block is selected, and the drainage length L=500m, the drainage width B=300m, and the reservoir porosity φ=0.0754 are obtained from the well test interpretation data. Substituting the above data into the hydrocarbon-containing height formula, the hydrocarbon-containing height of the Y-3 oil well in the limited closed block reservoir can be obtained;

[0126]

[0127] Where: N-dynamic reserves, m 3 ;φ-reservoir porosity; Swi -Immobilized water saturation.

[0128] The above description is not intended to impose any form of limitation on the present invention. Although the present invention has been disclosed through the above embodiments, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for back-calculating the dynamic reserves of hydrocarbon-bearing height of a finite closed massive oil and gas reservoir, characterized in that: The following steps are involved: Step S10, obtaining the production dynamic data of the target well, and obtaining the monthly wellhead pressure data according to the production dynamic data; Step S20, using the monthly wellhead pressure data and the pressure gradient to calculate the bottom hole flow pressure and formation pressure; Step S30, selecting a material balance equation according to the type of the target well, and then obtaining the dynamic reserves of the target well through the material balance equation; When the target well is an oil well, the following closed unsaturated reservoir material balance equation is selected: NB oi C t Δp=N p B o +N w B w Where: N-dynamic reserves, m 3 ; B oi - Volume coefficient of crude oil under original conditions, dimensionless; C t -Total compressibility of the reservoir, 1 / MPa; N p -Cumulative oil production, m 3 ; N w -Cumulative water production, m 3 ; B o -Crude oil volume coefficient, dimensionless; B w -Water volume coefficient, dimensionless; C o -Compression coefficient of crude oil, 1 / MPa; C w - Water compressibility, 1 / MPa; S wi -Immobile water saturation, dimensionless; C f - rock compression coefficient, 1 / MPa; Δp-pressure difference, MPa; When the target well is a gas well, the following constant volume gas reservoir material balance equation is selected: GB gi =(NG p )B g Where: N-dynamic reserves, m 3 ; B gi - Gas volume coefficient under original conditions; G p -Cumulative gas production, m 3 ; B g -Gas volume coefficient at current pressure; G-dynamic reserves, m 3 ; Step S40: Using geological data and drilling and completion data, different forms of drainage fluid models are selected according to the well layout of the target wells to perform dynamic reserve back calculation of hydrocarbon-bearing height.

2. The method for back-calculating the dynamic reserves of hydrocarbon-bearing height of a finite closed massive oil and gas reservoir according to claim 1, characterized in that: The specific process of step S20 is as follows: Step S201, selecting the wellhead pressure data of each month, and obtaining the bottom hole flowing pressure by using the known pressure gradient; Step S202, performing linear regression on the bottom hole flow pressure, and fitting to obtain a bottom hole flow pressure straight line; Step S203: Calculate the formation pressure line using the bottom hole flow pressure line, so that all formation pressure values ​​are greater than the maximum value of the bottom hole flow pressure.

3. The method for back-calculating the dynamic reserves of hydrocarbon-bearing height of a finite closed block oil and gas reservoir according to claim 1, characterized in that: In step S30, when the target well is an oil well, the specific calculation process of the dynamic reserves of the target well is: Step S31, let the horizontal coordinate X = △p, the vertical coordinate Y = N p B o +N w B w , draw the reservoir material balance straight line, then the closed unsaturated material balance equation becomes: Y=NB oi C t X Step S32: Draw a material balance analysis curve using relevant data. The curve is a straight line passing through the origin. A linear equation can be obtained from the data points on the straight line, and the slope α of the straight line can be obtained: Y=αX Where: α-slope of the straight line, m 3 / MPa; Step S33, the dynamic geological reserve N of the oil reservoir can be obtained by the slope of the linear equation; 4. The method for back-calculating the dynamic reserves of hydrocarbon-bearing height of a finite closed massive oil and gas reservoir according to claim 1, characterized in that: In step S30, when the target well is a gas well, the specific calculation process of the dynamic reserves of the target well is: Step S301: Substitute the material balance equation according to the definition of the gas volume coefficient and rewrite the material balance equation as follows: Where: p-current pressure, MPa; p i -Original pressure, MPa; Z-Deviation coefficient at current pressure, dimensionless; Z i - coefficient of deviation under original conditions, dimensionless; Step S302, using relevant data to draw a material balance analysis line, with the ordinate axis being the formation pressure coefficient and the abscissa axis being the cumulative gas production, and the line being extrapolated to p / Z=0 to obtain the dynamic reserve G; N=G p Where: G p -Cumulative gas production, m 3 ; N-dynamic reserves, m 3 .

5. A method for back-calculating the dynamic reserves of hydrocarbon-bearing height of a finite closed block oil and gas reservoir according to claim 3 or 4, characterized in that: In step S40, if the target well is drilled on a large fault block, a rectangular parallelepiped drainage model distributed along the large fault block is used to back-calculate the drainage volume of the dynamic reserves; the rectangular parallelepiped drainage model is controlled by the drainage length L, the drainage width B and the hydrocarbon-bearing height H, and the hydrocarbon-bearing height H is obtained by substituting the well test interpretation data into relevant data; If the target well is drilled on a small fault block, the cylindrical drainage model is used to backcalculate the drainage fluid volume from the dynamic reserves. The cylindrical drainage model is controlled by the drainage radius R and the hydrocarbon-bearing height H. The hydrocarbon-bearing height H is obtained by substituting the well test interpretation data into relevant data.

6. A method for back-calculating dynamic reserves of hydrocarbon-bearing height of a finite closed massive oil and gas reservoir according to claim 5, characterized in that: In step S40, if the target well is drilled on a large fault block, the calculation formula for its hydrocarbon content is as follows: Where: N-dynamic reserves, m 3 ;φ-reservoir porosity; S wi -Imposed water saturation; L-leakage length; B-leakage width.

7. The method for back-calculating the dynamic reserves of hydrocarbon-bearing height of a finite closed massive oil and gas reservoir according to claim 5, characterized in that: In step S40, if the target well is drilled on a small fault block, the calculation formula for its hydrocarbon content is as follows: Where: N-dynamic reserves, m 3 ;φ-reservoir porosity; S wi -Imposed water saturation; R-discharge radius.

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