Tight gas reservoir prediction method for calculating formation pressure based on basin simulation

Abstract

The invention discloses a tight gas reservoir prediction method for calculating formation pressure based on basin simulation, relates to the field of oil-gas exploration, and solves the problem that existing tight gas is difficult to benefit exploration and effectively use. The method comprises the following steps: S1, carrying out statistics on actually measured formation pressure data in a research area, and judging whether an overpressure gas reservoir condition exists in the area or not; s2, stratum paleo-pressure is recovered through inclusion calculation; s3, determining an overpressure formation mechanism on the basis of drilled data in the research area, and establishing a relational expression between the existing gas reservoir resource quantity or single well yield and pressure; s4, establishing a basin simulation model through basin simulation; and S5, dividing an overpressure area on the basis of the basin simulation model, and predicting a gas reservoir enrichment area in an overpressure environment. According to the tight gas reservoir prediction method for calculating the formation pressure based on basin simulation, gas reservoir enrichment prediction is carried out through basin pressure simulation and by applying the current formation residual pressure, a high-yield and stable-yield tight gas reservoir can be found, and the benefit gateway is broken through.

Description

Technical Field

[0001] This invention relates to the field of oil and gas resource exploration technology, and in particular to a method for predicting tight gas reservoirs based on basin simulation calculation of formation pressure. Background Technology

[0002] Tight gas reservoirs contain abundant natural gas resources. However, due to limitations in early exploration and processing technologies, they have not received sufficient attention, resulting in a relatively low level of development of global tight gas resources, despite their enormous potential. With the continuous advancement of exploration theories, tight gas reservoirs have become an important area of ​​oil and gas exploration.

[0003] Current research indicates that most tight gas reservoirs possess considerable resource potential. However, due to the poor reservoir properties, finding tight gas reservoirs that can be effectively utilized in the long term remains a major challenge. According to current research, tight gas reservoirs are more effective under overpressure conditions. Therefore, finding overpressure zones will be a key factor in the efficient exploration and effective utilization of tight gas reservoirs. Summary of the Invention

[0004] This invention addresses the problem of the difficulty in efficiently exploring and effectively utilizing tight gas in existing technologies by providing a method for predicting tight gas reservoirs based on basin simulation and formation pressure calculation. This method, through basin pressure simulation and the application of current residual formation pressure, predicts gas reservoir enrichment, particularly in areas with low well control. This helps to identify high-yield and stable-production tight gas reservoirs, overcoming the challenges of profitability.

[0005] The present invention solves its problem through the following technical solution: a method for predicting tight gas reservoirs based on basin simulation calculation of formation pressure, comprising the following steps:

[0006] S1: Statistically analyze the measured formation pressure data within the study area to determine whether the area has the conditions for overpressured gas reservoirs;

[0007] S2: Reconstructing formation paleopressure through inclusion calculations;

[0008] S3: Based on the existing drilling data in the study area, clarify the overpressure formation mechanism and establish the relationship between existing gas reservoir resources or single well production and pressure.

[0009] S4: Establish a basin simulation model through basin simulation;

[0010] S5: Based on the basin simulation model, overpressure zones are delineated, and gas reservoir enrichment areas are predicted under overpressure environments.

[0011] Preferably, the method for statistically analyzing the measured formation pressure data within the test area in step S1 is as follows:

[0012] When conducting basin simulation in the statistical study area, specific wells are required, and various types of well and seismic data are collected to prepare for the simulation.

[0013] The measured formation pressure data is the actual pressure measured by the pressure gauge after drilling; if it is not possible to measure the actual pressure data, the formation pressure measured during the gas testing process can be used instead.

[0014] Preferably, the method for determining whether the region possesses the conditions for an overpressured gas reservoir in step S1 is as follows:

[0015] Once the measured formation pressure is obtained, the measured formation pressure is the current formation pressure;

[0016] By comparing the current formation pressure with the formation hydrostatic pressure, the pressure coefficient of the drilled wells in the area is obtained.

[0017] Determine whether the pressure coefficient of the drilled wells in the area is greater than 1.2; if the pressure coefficient of the drilled wells in the area is greater than 1.2, then the conditions for an overpressured gas reservoir are met.

[0018] Preferably, the method for calculating the drilled pressure coefficient in the region is as follows: the ratio of the current formation pressure to the formation hydrostatic pressure is the drilled pressure coefficient.

[0019] Preferably, the method for recovering formation paleopressure by calculating inclusions in step S2 is as follows:

[0020] Obtain paleopressure data from multiple strata / geological periods as much as possible;

[0021] Paleopressure was obtained through the paleopressure simulation method of oil inclusions. This method uses PVTsim software in conjunction with confocal laser scanning microscopy to determine the captured pressure, thereby obtaining the paleopressure.

[0022] Preferably, the method for establishing the production and pressure formula based on existing drilling conditions in step S3 includes the following specific steps:

[0023] S101 used acoustic-density cross-plotting to conduct an analysis of the causes of overpressure and to clarify the mechanism of overpressure formation.

[0024] Based on the established overpressure formation mechanism, S102 statistically analyzes the gas production (Q) from existing well tests. 产 The data includes the formation residual pressure (P), reservoir thickness (H), and reservoir porosity (Φ) of the test section, and the Q of existing wells. 产 The gas production rate Q was obtained by fitting scatter plot data with P×H×Φ. 产 The fitting formula with the other three parameters, i.e., Q 产 =A×P×H×Φ;

[0025] Q产 : Drilled production, A; Fitted relationship or constant; P: Residual formation pressure; H: Favorable reservoir thickness; Φ: Reservoir porosity.

[0026] Preferably, the method for establishing the formula for gas reservoir resources and pressure based on existing drilling information in step S3 includes the following specific steps:

[0027] S201 used acoustic-density cross plotting to conduct an analysis of the causes of overpressure and to clarify the mechanism of overpressure formation.

[0028] Based on the established overpressure formation mechanism, S202 estimates the existing gas reservoir resources (Q). 资 The remaining pressure (P), reservoir volume (V), and reservoir porosity (Φ) of the gas reservoir are used to determine the known resource quantity Q of the gas reservoir. 资 By fitting scatter plots of data (P×V×Φ) to the gas reservoir resource quantity Q, we can obtain the gas reservoir resource quantity Q. 资 The fitting formula with the other three parameters, i.e., Q 资 =A×P×V×Φ;

[0029] Q 资 A: Gas reservoir resource quantity; P: Formation residual pressure; Φ: Reservoir porosity; V: Gas reservoir volume.

[0030] Preferably, step S4, the method for establishing a basin simulation model through basin simulation, includes the following steps:

[0031] S301 Establishing a stratigraphic structure model: Import the top surface structure files of each layer after correction using single-well layered data into PetroMod software to establish a stratigraphic structure model.

[0032] S302 assigns the known stratigraphic age to the structural model built in step S301, giving it both temporal and spatial concepts.

[0033] S303 adds known lithological data to the geological structure model established in step S302, thereby giving the structure model lithological characteristics; and imports physical properties, permeability and organic geochemical indicators for each stratum, so that it has the property characteristics of caprock, reservoir and source rock.

[0034] S304 imports the fracture data volume and the erosion amount of each layer into the structural model constructed in step S303, so that the established structural model can recover the paleotectonic evolution characteristics.

[0035] S305 sets boundary conditions in the model of S304, including simulation parameters such as paleogeographic heat flow, paleotemperature, and paleowater depth.

[0036] S306 Based on the structural model established in step S305, basin simulation is carried out. The simulated structural model is corrected for the simulated burial history and temperature and pressure history based on the current stratum temperature, current mudstone vitrinite reflectivity, current stratum pressure and paleostratum pressure; thus obtaining the corrected simulated structural model.

[0037] Preferably, step S5, which involves dividing the overpressure zone based on a basin simulation model and predicting gas reservoir enrichment areas under overpressure conditions, is as follows:

[0038] The three-dimensional distribution characteristics of pressure in the basin can be seen in the simulation results that have been corrected in step S306, thereby obtaining the regional pressure characteristics. Based on this, the distribution range of the normal pressure zone, weak overpressure zone and overpressure zone of the target layer in the basin can be divided.

[0039] Within the defined overpressure zones, the difference between the formation pressure of the source rock and the reservoir formation pressure during the hydrocarbon accumulation period is calculated. If the difference is greater than the displacement pressure of the tight sandstone and conglomerate reservoir, large-scale hydrocarbon accumulation is possible. The predicted current formation pressure is derived from the corrected simulated structural model, and the calculation formula Q fitted in step 2 is used. 产 =A×P×H×Φ or Q 资 =A×P×V×Φ, within the range of high-quality reservoir distribution, predict the distribution range, resource volume and single-well production of high-yield gas reservoirs based on the residual pressure.

[0040] Preferably, the displacement pressure of the tight sandstone and conglomerate reservoir is 10 MPa.

[0041] Basin simulation technology integrates well and seismic data to simulate hydrocarbon systems from one-dimensional to three-dimensional. The simulation results allow for a direct observation of the changing characteristics of various parameters of the hydrocarbon system, enabling the reconstruction of the burial history and formation history of oil and gas reservoirs, and helping geologists make well location deployment decisions.

[0042] Compared with the above-mentioned background technology, the present invention has the following beneficial effects:

[0043] This invention proposes a method for predicting tight gas reservoirs based on basin simulation and formation pressure calculation. Addressing the challenge of effectively utilizing tight gas, this invention is specifically designed for tight sandstone and conglomerate exploration areas, particularly those with low well control. Through basin pressure simulation, this invention first analyzes the source rock's injection intensity into the reservoir during the reservoir formation period. Then, based on the current formation pressure, it predicts gas reservoir enrichment, which helps identify high-yield and stable-production gas reservoirs, providing support for increased natural gas production. This has a positive impact on ensuring national energy security and economic development. Attached Figure Description

[0044] Figure 1 This is a flowchart illustrating the tight gas reservoir prediction method of the present invention.

[0045] Figure 2 This is a planar distribution diagram of the pressure coefficient according to an embodiment of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0047] like Figure 1 As shown, a method for predicting tight gas reservoirs based on basin simulation calculation of formation pressure includes the following steps:

[0048] S1: Statistically analyze the measured formation pressure data within the study area to determine whether the area has the conditions for overpressured gas reservoirs;

[0049] When conducting basin simulation in the statistical study area, specific wells are required, and various types of well and seismic data are collected to prepare for the simulation.

[0050] The measured formation pressure data is the actual pressure measured by the pressure gauge after drilling; if it is not possible to measure the actual pressure data, the formation pressure measured during the gas testing process can be used instead.

[0051] The method for determining whether the region possesses the conditions for an overpressured gas reservoir is as follows:

[0052] Once the measured formation pressure is obtained, the measured formation pressure is the current formation pressure;

[0053] By comparing the current formation pressure with the formation hydrostatic pressure, the drilled well pressure coefficient in the region is obtained; the ratio of the current formation pressure to the formation hydrostatic pressure is the drilled well pressure coefficient.

[0054] Determine whether the pressure coefficient of the drilled wells in the area is greater than 1.2; if the pressure coefficient of the drilled wells in the area is greater than 1.2, then the conditions for an overpressured gas reservoir are met.

[0055] S2: Reconstructing paleopressure of formations through inclusion calculations; the specific method is as follows:

[0056] Obtain paleopressure data from multiple strata / geological periods as much as possible;

[0057] Paleopressure was obtained through the paleopressure simulation method of oil inclusions. This method uses PVTsim software in conjunction with confocal laser scanning microscopy to determine the captured pressure, thereby obtaining the paleopressure.

[0058] S3: Based on the existing drilling data in the study area, clarify the overpressure formation mechanism and establish the relationship between existing gas reservoir resources or single well production and pressure.

[0059] The method for establishing a formula for production and pressure based on existing drilling data includes the following specific steps:

[0060] S101 used acoustic-density cross-plotting to conduct an analysis of the causes of overpressure and to clarify the mechanism of overpressure formation.

[0061] Based on the established overpressure formation mechanism, S102 statistically analyzes the gas production (Q) from existing well tests. 产 The data includes the formation residual pressure (P), reservoir thickness (H), and reservoir porosity (Φ) of the test section, and the Q of existing wells. 产 The gas production rate Q was obtained by fitting scatter plot data with P×H×Φ. 产 The fitting formula with the other three parameters, i.e., Q 产 =A×P×H×Φ;

[0062] Q 产 : Drilled production, A; Fitted relationship or constant; P: Residual formation pressure; H: Favorable reservoir thickness; Φ: Reservoir porosity;

[0063] The method for establishing a formula for gas reservoir resources and pressure based on existing drilling data includes the following specific steps:

[0064] S201 used acoustic-density cross plotting to conduct an analysis of the causes of overpressure and to clarify the mechanism of overpressure formation.

[0065] Based on the established overpressure formation mechanism, S202 estimates the existing gas reservoir resources (Q). 资 The remaining pressure (P), reservoir volume (V), and reservoir porosity (Φ) of the gas reservoir are used to determine the known resource quantity Q of the gas reservoir. 资 By fitting scatter plots of data (P×V×Φ) to the gas reservoir resource quantity Q, we can obtain the gas reservoir resource quantity Q. 资 The fitting formula with the other three parameters, i.e., Q 资 =A×P×V×Φ;

[0066] Q 资 A: Gas reservoir resource quantity; P: Formation residual pressure; Φ: Reservoir porosity; V: Gas reservoir volume.

[0067] S4: Establish a basin simulation model through basin simulation; the specific method includes the following steps:

[0068] S301 Establishing a stratigraphic structure model: Import the top surface structure files of each layer after correction using single-well layered data into the software PetroMod to establish a stratigraphic structure model.

[0069] S302 assigns the known stratigraphic age to the structural model built in step S301, giving it both temporal and spatial concepts.

[0070] S303 adds known lithological data to the geological structure model established in step S302, thereby giving the structure model lithological characteristics; and imports physical properties, permeability and organic geochemical indicators for each stratum, so that it has the property characteristics of caprock, reservoir and source rock.

[0071] S304 imports the polygon fracture data volume and the erosion amount of each layer into the structural model constructed in step S303, so that the established structural model can recover the paleotectonic evolution characteristics.

[0072] S305 sets boundary conditions in the model of S304, including simulation parameters such as paleogeographic heat flow, paleotemperature, and paleowater depth.

[0073] S306 Based on the structural model established in step S305, basin simulation is carried out. The simulated structural model is corrected for the simulated burial history and temperature and pressure history based on the current stratum temperature, current mudstone vitrinite reflectance value, current stratum pressure and paleostratum pressure (i.e., paleopressure); the corrected simulated structural model is obtained.

[0074] S5: Based on the basin simulation model, overpressure zones are delineated, and gas reservoir enrichment areas under overpressure environments are predicted; the specific method is as follows:

[0075] The three-dimensional distribution characteristics of pressure in the basin can be seen in the simulation results that have been corrected in step S306, thereby obtaining the regional pressure characteristics. Based on this, the distribution range of the normal pressure zone, weak overpressure zone and overpressure zone of the target layer in the basin can be divided.

[0076] Within the defined overpressure zones, the difference between the formation pressure of the source rock and the reservoir formation pressure during the hydrocarbon accumulation period is calculated. If the difference is greater than the displacement pressure of the tight sandstone and conglomerate reservoir, large-scale hydrocarbon accumulation is possible. The predicted current formation pressure is derived from the corrected simulated structural model, and the calculation formula Q fitted in step 2 is used. 产 =A×P×H×Φ or Q 资 =A×P×V×Φ, within the range of high-quality reservoir distribution, predict the distribution range, resource volume and single-well production of high-yield gas reservoirs based on the remaining pressure; the displacement pressure of the tight sandstone and conglomerate reservoir is 10 MPa.

[0077] Example 1

[0078] The technical features, objectives, and effects of the present invention will be described in detail below with reference to the accompanying drawings. In order to illustrate the specific operability and practicality of the method, the application block of the present invention is the XS block, the main target stratigraphic unit is the Shahezi Formation, and a basin simulation model is built for the XS block.

[0079] The following section provides a detailed description of each step of the implementation plan for the tight gas reservoir prediction method based on basin simulation calculation of formation pressure in this invention, using a practical scenario.

[0080] Step 1: Statistically analyze the measured formation pressure data in the study area to determine whether the area has the conditions for an overpressured gas reservoir;

[0081] The data collected in step 1 of this plan is mainly for calibrating the established geological model, including data from various drilled wells and seismic data. The data primarily consists of downhole measured formation pressure and paleopressures reconstructed from fluid inclusions; this pressure data ensures the accuracy of the simulated pressure. Calculations of the current formation pressure and formation hydrostatic pressure from drilled wells in this block show that the pressure coefficients of drilled wells in this area are generally between 1.3 and 1.5, indicating the potential for overpressure gas reservoir formation. Further investigation into the overpressure distribution characteristics is needed.

[0082] Step 2: Calculate paleopressure from inclusions representing current formation pressure;

[0083] Step 3: Based on the existing drilling data in the study area, clarify the overpressure formation mechanism and establish the relationship between existing gas reservoir resources or single well production and pressure;

[0084] Specifically, this plan mainly consists of the following steps:

[0085] S201 uses the acoustic-density intersection plot method to confirm that the main contributing factor to the overpressure in the XS block is hydrocarbon generation and pressurization. This means that during the hydrocarbon generation period, the amount of hydrocarbons generated is large, and due to the tightness of the reservoir, large types of hydrocarbon gases cannot be discharged, thus forming an overpressured gas reservoir.

[0086] S202, Statistics on gas production from 10 exploration wells in the Shahezi Formation (Q) 产 The formation residual pressure (P), reservoir thickness (H), and porosity data (Φ) obtained from well logging interpretation or experimental analysis of the test section are used to determine the Q of these wells. 产 The gas production rate Q was obtained by fitting scatter plot data with P×H×Φ. 产 The formula for the other three parameters is:

[0087] Q 产 =A×P×H×Φ;

[0088] Q 产 : Drilled well production, A; Fitted relationship or constant; P: Residual formation pressure; H: Favorable reservoir thickness; Φ: Reservoir porosity

[0089] S203. Calculate the gas reservoir resources (Q) of the four most explored blocks (XS-A, XS-X, XS-D, and XS-AB) in the XS block. 资The data includes the residual pressure (P), reservoir volume (V), and porosity (Φ) within the gas reservoir, using the existing well's Q... 资 By fitting scatter plots of data (P×V×Φ) to the gas reservoir resource quantity Q, we can obtain the gas reservoir resource quantity Q. 资 The fitting formula with the other three parameters is:

[0090] Q 资 =A×P×V×Φ;

[0091] Q 资 A: Gas reservoir resource quantity; P: Formation residual pressure; Φ: Reservoir porosity; V: Gas reservoir volume.

[0092] After establishing the formula for single-well production and gas reservoir resources using the above method, the residual pressure of the formation can be used to estimate the production or resources of new wells or gas reservoirs with low exploration levels.

[0093] Step 4: Establish a basin simulation model through basin simulation; calculate regional formation pressure, and delineate overpressure zones based on pressure coefficient or residual pressure.

[0094] Specifically, this solution mainly uses PetroMod to conduct basin simulation, and the specific steps are as follows:

[0095] S301. Using the existing tectonic maps, construct the framework of the XS block basin model, which consists of 13 layers. Assign age to each layer based on the currently known geological ages.

[0096] S302. Using lithological distribution maps and lithofacies maps of each stratum, the lithology of each location in each stratum is delineated, and a lithological model is built. Using porosity prediction maps, physical property data are assigned to the corresponding lithologies. For mudstone strata, source rock parameter prediction maps are used to assign values ​​to the source rocks, and appropriate hydrocarbon generation kinetic equations are selected.

[0097] S303. Based on earthquake fault interpretation and fault conduction evaluation, establish a fault model; import erosion data of each layer to restore paleotectonic features;

[0098] S304. Based on the historical evolution of the XS block, and by consulting relevant literature, boundary conditions for paleowater depth, paleotemperature, and paleogeographic heat flow were set.

[0099] S305. Conduct basin simulation. The results of basin simulation may deviate from reality. Based on the simulation results, firstly, apply the data such as Ro of the mudstone of the currently drilled wells in the XS block and the formation temperature of the oil test to perform temperature evolution correction. Then, apply the measured formation pressure and the paleopressure obtained from fluid inclusions to correct the pressure.

[0100] S306. From the simulation results, we can obtain the predicted distribution of pressure coefficient and the predicted distribution of residual pressure in the Shahezi Formation of Block XS, etc. (See...) Figure 2 According to the map, the XS block can be divided into overpressure, weak overpressure and normal pressure zones. Based on this model, the distribution range of overpressure gas reservoirs can be determined.

[0101] Step 5: Based on the study of hydrocarbon accumulation dynamics, predict the gas reservoir enrichment areas under overpressure conditions;

[0102] Specifically, the steps of this plan include applying basin simulation results to delineate favorable exploration areas and predicting the production of design wells. The specific methods are as follows:

[0103] S401. In the currently defined overpressure and weak overpressure zones of the XS block, conduct burial history analysis. During the period of large-scale oil and gas injection, read the difference between the formation pressure and reservoir pressure of the mudstone. If it is greater than the reservoir displacement pressure (10MPa), it is a dominant reservoir formation area. This clarifies the distribution range of high-pressure and high-yield gas reservoirs in the XS block and delineates favorable exploration areas.

[0104] S402. Based on the identification of favorable exploration areas in the XS block, derive the simulated current residual pressure of the formation in the XS block, and apply Q... 资 =A×P×V×Φ, predicting the gas resource quantity in the favorable area of ​​block XS. After obtaining the gas resource quantity of several favorable areas, the gas resource quantity is used as an indicator to rank the favorable areas. In the favorable area with the best exploration conditions, Q is applied. 产 =A×P×H×Φ, predicting the production of the designed well or the well to be drilled, providing a new basis for decision-making on the deployment of tight gas wells in the XS block.

[0105] In summary, the basic principles, main features, and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

[0106] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the implementation methods of the present invention, and should be understood that the scope of protection of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of the present invention.

Claims

1. A method for predicting tight gas reservoirs based on basin modeling to calculate formation pressure, characterized in that: The method comprises the following steps: S1: statistics of measured formation pressure data in the study area, to determine whether the region has the conditions of overpressure gas reservoir; S2: calculate the formation paleo-pressure by inclusion; S3: to clarify the overpressure formation mechanism based on the data of drilled wells in the study area, and establish the relationship between the existing gas reservoir resources or single well production and pressure; S4: through the basin simulation, to establish the basin simulation model; S5: to divide the overpressure area based on the basin simulation model, and predict the gas reservoir enrichment area under the overpressure environment.

2. The method of claim 1, wherein the method is characterized by: The method of statistics of measured formation pressure data in the study area in step S1 is as follows: The specific wells needed for the basin simulation of the study area are collected, and all kinds of well and seismic data are collected for simulation preparation; The measured formation pressure data are the actual pressure measured by pressure gauge after drilling; if the actual pressure data cannot be measured, the formation pressure measured during gas testing can be used instead.

3. The method of claim 1, wherein the method is characterized by: The method of determining whether the region has the conditions of overpressure gas reservoir in step S1 is as follows: After obtaining the measured formation pressure, the measured formation pressure is the present formation pressure; The present formation pressure is compared with the formation hydrostatic pressure, and the drilled well pressure coefficient in the region is obtained; It is determined whether the drilled well pressure coefficient in the region is greater than 1.2; if the drilled well pressure coefficient in the region is greater than 1.2, the region has the conditions of overpressure gas reservoir.

4. The method of claim 3, wherein the method further comprises: The calculation method of the drilled well pressure coefficient in the region is as follows: the ratio of the present formation pressure to the formation hydrostatic pressure is the drilled well pressure coefficient.

5. The method of claim 1, wherein: The method of calculating the formation paleo-pressure by inclusion in step S2 is as follows: As many paleo-pressures as possible are obtained at different horizons / geological periods; The paleo-pressure is obtained by oil inclusion paleo-pressure simulation method; the oil inclusion paleo-pressure simulation method uses PVTsim software and confocal laser scanning microscope to determine the capture pressure, so as to obtain the paleo-pressure.

6. The method of claim 1, wherein: The method of establishing the formula of production and pressure in step S3 is as follows: S101: use acoustic-density cross plot means to carry out overpressure genesis analysis, and clarify the overpressure formation mechanism; S102On the basis of the identified overpressure formation mechanism, the existing well test gas production (Q 产 ), the formation residual pressure of the test gas section (P), the reservoir thickness of the test gas section (H), and the porosity data of the reservoir (Φ) are counted, and the Q 产 and P×H×Φ of the existing well are fitted by scatter data to obtain the fitting formula of the test gas production Q 产 and the remaining three parameters, that is, Q 产 =A×P×H×Φ. Q 产 : drilled well production, A; fitted relationship or constant; P: formation residual pressure; H: favorable reservoir thickness; Φ: reservoir porosity.

7. The method of claim 1, wherein: The method of establishing the formula of gas reservoir resources and pressure according to the existing drilled well conditions in step S3 is as follows: S201: use acoustic-density cross plot means to carry out overpressure genesis analysis, and clarify the overpressure formation mechanism; S202. Based on the established overpressure formation mechanism, calculate the existing gas reservoir resources (Q). 资 The remaining pressure (P), reservoir volume (V), and reservoir porosity (Φ) of the gas reservoir are used to determine the known resource quantity Q of the gas reservoir. 资 By fitting scatter plots of data (P×V×Φ) to the gas reservoir resource quantity Q, we can obtain the gas reservoir resource quantity Q. 资 The fitting formula with the other three parameters, i.e., Q 资 =A×P×V×Φ; Q 资 : gas reservoir resource quantity, A; fitted relationship or constant; P: formation residual pressure; Φ: reservoir porosity; V: gas reservoir gas-bearing volume.

8. The method of claim 1, wherein the method is a method of predicting formation pressure in a tight gas reservoir based on basin simulation. The method of establishing the basin simulation model through the basin simulation in step S4 comprises the following steps: S301: establish the formation structure model: import the top surface structure file of each horizon corrected by single well layered data into PetroMod software to establish the formation structure model; S302: assign the known formation age to the structure model built in step S301, so that it has the concepts of time and space; S303: add the known lithology data to the geological structure model established in step S302, so that the structure model has lithology characteristics; import the physical property, permeability and organic geochemical index of each formation, so that it has the property characteristics of cap rock, reservoir and source rock layer; S304, the fracture data body and the denudation amount of each layer are introduced into the structure model constructed in step S303, so that the established structure model can restore the paleo-tectonic evolution characteristics; S305, in the model of S304, the boundary conditions including simulation parameters such as paleo-geothermal flow value, paleo-air temperature, paleo-water depth are set; S306, according to the structure model established in step S305, the basin simulation is carried out, and according to the present stratum temperature, the present mudstone vitrinite reflectance value, the present stratum pressure and the paleo-stratum pressure, the simulated burial history and the temperature-pressure history are corrected; the corrected simulation structure model is obtained.

9. The method of claim 1 or 8, wherein: The step S5 divides the overpressure area based on the basin simulation model, and the method for predicting the gas reservoir enrichment area in the overpressure environment is: In the corrected simulation result of step S306, the three-dimensional distribution characteristics of the pressure of the basin can be seen, so that the pressure characteristics of the region are obtained, and on this basis, the distribution range of the normal pressure area, the weak overpressure area and the overpressure area of the target layer in the basin is divided; In the divided overpressure zones, the difference between the formation pressure of the source rock in the accumulation period and the reservoir formation pressure is calculated. If the difference is greater than the displacement pressure of the dense sandstone reservoir, large-scale accumulation can occur. From the corrected simulation structure model, the predicted present formation pressure is derived. According to the calculated formula Q 产 =A×P×H×Φ or Q 资 =A×P×V×Φ, in the distribution range of high-quality reservoirs, the distribution range, resource volume and single-well production of high-yield gas reservoirs are predicted according to the remaining pressure.

10. The method of claim 9, wherein the method is based on basin modeling to calculate formation pressure for tight gas reservoir prediction. The displacement pressure of the tight sandstone conglomerate reservoir is 10Mpa.

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