A quantitative simulation method for the contribution of sandstone overpressure genesis

Abstract

The present invention relates to a quantitative simulation method for the contribution of sandstone overpressure genesis, which comprises: collecting, arranging and analyzing test, well logging, geological and seismic data; analyzing the formation pressure characteristics of target layer sandstone; reconstructing the burial history and thermal history of target layer sandstone; quantitatively simulating the evolution history of undercompacted pore pressure; quantitatively simulating the evolution history of undercompacted and hydrocarbon-generated pore pressure; quantitatively simulating the evolution history of total pore pressure; conducting quantitative analysis of the contribution of overpressure genesis, and according to P total =P underc +P hydrog and P total =P underc +P hydrog +P other , quantitatively analyze the contribution of undercompaction, hydrocarbon generation and other causes to overpressure, obtain three causes of overpressure evolution mechanisms, quantitatively simulate the contribution of sandstone overpressure, and determine the geological exploration area of ​​oil and gas reservoirs. The present invention meets the current needs of oil and gas reservoir geological exploration, and has guiding significance for the quantitative analysis of sandstone overpressure contribution and the exploration of oil and gas reservoirs.

Description

Technical field:

[0001] The invention relates to the technical field of oil and gas reservoir geological exploration, and in particular to a quantitative simulation method for the genetic contribution of sandstone overpressure. Background technology:

[0002] Understanding and predicting subsurface pressure conditions are critical to all aspects of upstream activities such as exploration, drilling, and production. Overpressure is the result of the inability of formation fluids to escape at a rate that is in equilibrium with the formation water column present at the surface. When the pore fluid pressure is higher than the hydrostatic pressure, it is called overpressure, and its upper limit is the formation fracture pressure. Normal pressure formations are characterized by high overall density, high compaction rate, and high effective stress, while highly overpressured formations are characterized by high porosity, high pore pressure, and high formation temperature (Dutta, 2002). There are many mechanisms to explain the high pressure phenomenon in sedimentary basins, mainly including (1) abnormal high pressure caused by undercompaction, (2) abnormal high pressure formed by large-scale tectonic compression, (3) abnormal high pressure caused by hydrothermal pressurization, (4) abnormal overpressure caused by dehydration reactions related to mineral diagenesis, and (5) abnormal high pressure caused by thermal maturation of kerogen to increase the volume of pore fluids. The existence of global overpressure is usually related to the following factors: Tertiary basins, rapid sedimentation and subsidence, and compressional tectonic activity.

[0003] The causes of overpressure include mechanical compaction, chemical compaction, hydrocarbon generation pressurization, thermal expansion, mineral dehydration and montmorillonite-illite transformation. Previously, scholars have conducted a lot of research on overpressure, such as calculation of formation overpressure caused by undercompaction, prediction of formation pressure caused by organic matter hydrocarbon generation, prediction of formation overpressure caused by mixed undercompaction and hydrocarbon generation, calculation of overpressure contribution ratio of two pressure causes, and evaluation of overpressure caused by undercompaction and fluid expansion. However, these quantitative characterization methods of sandstone overpressure only consider the evaluation of one or two overpressure mechanisms, but do not consider the research on overpressure cause mechanism and contribution of numerical simulation methods. When used to analyze the contribution of formation overpressure, they cannot effectively evaluate the contribution of multiple causes. Therefore, it is necessary to explore a quantitative analysis process of sandstone overpressure contribution based on numerical simulation methods. Summary of the invention:

[0004] The purpose of the present invention is to provide a quantitative simulation method for the genetic contribution of sandstone overpressure, which is used to overcome the problem of unclear genetic contribution of overpressure in characterizing formation overpressure through undercompaction and hydrocarbon generation prediction models.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a quantitative simulation method of the contribution of sandstone overpressure genesis comprises the following steps:

[0006] Step 1) Collect the analytical test, logging, geological and seismic data of the target layer sandstone. The analytical test data include conventional core analysis, casting thin section and scanning electron microscope image data, organic geochemical data; the geological data include drilling layer data, formation pressure data, formation temperature data, vitrinite reflectance data, and formation age data;

[0007] Step 2) According to the formation pressure data, a formation pressure profile is established, the formation pressure characteristics of the sandstone in the target layer of the target area are analyzed, and a pressure simulation numerical model is established. The pressure simulation numerical model is established based on the actual formation characteristics and actual geological data of the target layer, involving burial history, thermal history and pressure history;

[0008] Step 3) Burial history reconstruction: Based on geological stratification, stratigraphic age data, denudation period and thickness, establish the one-dimensional burial history of the target layer sandstone;

[0009] Step 4), thermal history reconstruction: implant the formation temperature data and geothermal gradient data of the target layer sandstone into the pressure simulation numerical model to reconstruct the thermal history of the target layer sandstone; when the simulated formation temperature value is consistent with the measured formation temperature value, it indicates that the reconstructed thermal history is accurate;

[0010] Step 5), quantitatively simulate the evolution history of undercompacted pore pressure;

[0011] Step 6), quantitatively simulating the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization;

[0012] Step 7), quantitatively simulate the total pore pressure evolution history;

[0013] Step 8), quantitative analysis of overpressure genesis contribution: when the total pore pressure evolution history is greater than the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, the overpressure of the target layer sandstone is contributed by undercompaction, hydrocarbon generation pressurization and the third cause, and the contribution of undercompaction, hydrocarbon generation pressurization and the third cause to the total overpressure is quantitatively analyzed; when the total pore pressure evolution history is equal to the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, the overpressure of the target layer sandstone is contributed by two causes, undercompaction and hydrocarbon generation pressurization, and the contribution of undercompaction and hydrocarbon generation pressurization to the total overpressure is quantitatively analyzed.

[0014] The method for quantitatively simulating the evolution history of undercompacted pore pressure in the above scheme is as follows: based on conventional core analysis data, the distribution range and average value of the porosity and permeability of the target layer sandstone and the overburden are statistically analyzed; the porosity and permeability of the target layer sandstone are input into the pressure simulation numerical model, the porosity and permeability of the overburden are determined, and the evolution history of undercompacted pore pressure is quantitatively simulated.

[0015] The method for quantitatively simulating the evolution history of undercompacted pore pressure in the above scheme is:

[0016] According to the burial history and thermal history of the target sandstone, determine the oil and gas system where the target sandstone is located, including source rock, reservoir and cap rock;

[0017] The porosity-depth relationship charts and porosity-permeability relationship charts of the target sandstone layer and multiple sets of caprocks are carefully prepared, and these two charts are embedded in the pressure simulation numerical model as constraints to quantitatively simulate the under-compacted pore pressure evolution history of the target sandstone layer.

[0018] The method for quantitatively simulating the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization in the above scheme is as follows: based on organic geochemical data, the kerogen type, organic carbon and original hydrocarbon generation potential of the underlying source rock of the target layer sandstone are investigated; on the basis of quantitatively simulating the pore pressure evolution history of undercompaction, the kerogen type of the underlying source rock of the target layer sandstone is determined, and the average values ​​of organic carbon and original hydrocarbon generation potential and the vitrinite reflectance data of the source rock are input into the pressure simulation numerical model; when the simulated vitrinite reflectance value is consistent with the measured vitrinite reflectance value, it indicates that the quantitatively simulated pore pressure evolution history of undercompaction and hydrocarbon generation pressurization is accurate;

[0019] The pore pressure evolution history of undercompaction, undercompaction and hydrocarbon generation pressurization are combined to obtain the pore pressure evolution history of hydrocarbon generation pressurization.

[0020] P hydrog =P underc+hydrog -P underc

[0021] Where: P underc+hydrog It refers to the pore pressure of undercompaction and hydrocarbon generation pressurization; P underc refers to the undercompacted pore pressure; P hydrog It refers to the pore pressure caused by hydrocarbon generation.

[0022] The method for quantitatively simulating the total pore pressure evolution history in the above scheme is as follows: based on the measured formation pressure data, the formation pressure characteristics of the target layer sandstone are analyzed; on the basis of quantitatively simulating the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, the measured formation pressure data is used to correct the simulated formation pressure data; when the measured formation pressure value is consistent with the simulated formation pressure value, the total pore pressure evolution history is quantitatively simulated;

[0023] Based on the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, and the total pore pressure evolution history, the pore pressure of other origins is evaluated;

[0024] P other =P total -P underc+hydrog

[0025] Where: P underc+hydrogIt refers to the pore pressure of undercompaction and hydrocarbon generation pressurization; P total is the total pore pressure; P other Refers to pore pressure of other causes.

[0026] The method for quantitatively simulating the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization in the above scheme: quantitative analysis of the contribution of overpressure causes.

[0027] Quantitative analysis of overpressure contribution: pore pressure evolution history of combined undercompaction (P underc ), undercompaction and hydrocarbon generation pressurization pore pressure evolution history (P hydrog ), the total pore pressure evolution history (P total ), when the total pore pressure evolution history is equal to the pore pressure evolution history of undercompaction and hydrocarbon generation, the overpressure of the target layer sandstone is contributed by undercompaction and hydrocarbon generation. By combining the pore pressure evolution history of undercompaction and the pore pressure evolution history of undercompaction and hydrocarbon generation, the undercompaction (P underc ) and hydrocarbon generation pressure (P hydrog ) for total overpressure (P total )’s contribution;

[0028] P total =P underc +P hydrog

[0029] Where: P total is the total pore pressure; P underc refers to the undercompacted pore pressure; P hydrog It refers to the pore pressure caused by hydrocarbon generation.

[0030] When the total pore pressure evolution history is greater than the pore pressure evolution history of undercompaction and hydrocarbon generation, the overpressure of the target layer sandstone is contributed by undercompaction, hydrocarbon generation and other causes. The undercompaction (P underc ), hydrocarbon generation pressure boost (P hydrog ) and other causes (P other ) for total overpressure (P total )’s contribution;

[0031] P total =P underc +P hydrog +P other

[0032] Where: P total is the total pore pressure; P underc refers to the undercompacted pore pressure; P hydrog It refers to the pore pressure of hydrocarbon generation; Pother Refers to pore pressure of other causes.

[0033] The present invention innovatively and quantitatively simulates the contribution of sandstone overpressure genesis and quantitatively analyzes three overpressure genesis contributions; moreover, the specific genesis mechanism of pore pressure of other causes can be determined in combination with the regional tectonic characteristics, geological data and seismic data of the study area.

[0034] Beneficial effects:

[0035] 1. The present invention is achieved through formation pressure characteristics, burial history-thermal history reconstruction, quantitative simulation of undercompacted pore pressure evolution history, quantitative simulation of undercompacted and hydrocarbon generation pore pressure evolution history, quantitative simulation of total pore pressure evolution history and quantitative analysis of overpressure contribution, thereby quantitatively simulating the sandstone overpressure contribution and determining the geological exploration area of ​​the oil and gas reservoir.

[0036] 2. The present invention has made innovations in overpressure numerical simulation and formation overpressure mechanism analysis technology, and has formed a quantitative simulation method for the contribution of sandstone overpressure genesis by comprehensively considering analytical testing, logging, geological and seismic data, and proposed a multi-stage overpressure evolution mechanism, which has improved the theoretical understanding of the overpressure genesis mechanism. It fills the gap in the application of numerical simulation methods in the field of overpressure genesis mechanism analysis technology, uses numerical simulation methods to quantitatively analyze overpressure genesis contributions, and can conduct numerical simulation research on overpressure of target stratum sandstone down to sand layer groups / small layers according to the needs of oilfield researchers. This method is scientific and universal.

[0037] 3. The present invention forms a set of quantitative analysis processes for the contribution of sandstone overpressure genesis based on numerical simulation methods, which can provide better service support for the evaluation of underground pressure conditions and overpressure genesis mechanisms in oil and gas reservoir geological exploration areas.

[0038] 4. The present invention is feasible, has good evaluation effect, and solves practical problems. It has the following innovative features: 1) analyzing the formation pressure characteristics of the target layer sandstone; 2) reconstructing the burial history and thermal history of the target layer sandstone; 3) quantitatively simulating the evolution history of pore pressure under compaction; 4) quantitatively simulating the evolution history of pore pressure under compaction and hydrocarbon generation; 5) quantitatively simulating the evolution history of total pore pressure; 6) quantitatively analyzing the contribution of overpressure genesis. This method meets the current needs of geological exploration of oil and gas reservoirs, and has guiding significance for the quantitative analysis of the contribution of sandstone overpressure genesis and the exploration of oil and gas reservoirs.

[0039] 5. The present invention is based on analytical testing, logging, geological and seismic data to carry out quantitative analysis of the formation pressure characteristics of the target layer sandstone, burial history-thermal history reconstruction, under-compacted pore pressure evolution history, under-compacted and hydrocarbon-generated pore pressure evolution history, total pore pressure evolution history, and overpressure contribution, thus forming a quantitative analysis method for sandstone overpressure contribution.

[0040] 6. The present invention considers formation pressure characteristics, undercompacted pore pressure evolution history, undercompacted and hydrocarbon generation pore pressure evolution history, and total pore pressure evolution history to quantitatively analyze the contribution of sandstone overpressure formation; reconstructs the burial history and thermal history of the target layer sandstone based on geological stratification, formation age data, erosion period and thickness, and formation temperature data; compiles the porosity and permeability values ​​of the target layer sandstone and the overburden, the kerogen type of the underlying source rock, organic carbon and original hydrocarbon generation potential, and formation pressure profile based on conventional core analysis data, organic geochemical data, and measured formation pressure data, and these parameters can provide key parameters for overpressure numerical simulation research; meets the needs of quantitative analysis of the sandstone overpressure formation mechanism in the oil and gas reservoir geological exploration area, quantitatively simulates the sandstone overpressure evolution history and three overpressure formation evolution mechanisms, and provides a theoretical basis for the analysis of the sandstone overpressure formation mechanism in the oil and gas reservoir geological exploration area.

[0041] 7. The present invention proposes a quantitative simulation method for the genetic contribution of sandstone overpressure. Based on the accurate burial history and thermal history, the method quantitatively simulates the pore pressure evolution history of undercompaction, the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, and the total pore pressure evolution history, and quantitatively evaluates the contribution of undercompaction, hydrocarbon generation pressurization and other causes to the total overpressure, thereby quantitatively simulating the genetic contribution of sandstone overpressure. Description of the drawings:

[0042] Figure 1 It is a flow chart of the present invention.

[0043] Figure 2 It is a cross-sectional diagram of the measured reservoir temperature and depth of the target sandstone layer in the XX Basin.

[0044] Figure 3 It is a cross-sectional diagram of the measured formation pressure and depth of the target sandstone layer in the XX Basin.

[0045] Figure 4 It is the burial history of the Huangliu Formation sandstone in Well XX1 in the XX Basin.

[0046] Figure 5 This is a comparison chart between the measured temperature values ​​and the simulated temperature values ​​of the Huangliu Formation sandstone in Well XX1 in the XX Basin.

[0047] Figure 6 It is the evolution history of the undercompacted pore pressure of the target sandstone layer in the XX Basin.

[0048] Figure 7 It is the kerogen type of the underlying source rock in the XX Basin.

[0049] Figure 8 It is the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization of the Huangliu Formation sandstone in Well XX1 in the XX Basin.

[0050] Fig. 9 This is the total pore pressure evolution history of the Huangliu Formation sandstone in Well XX1 in the XX Basin.

[0051] Fig.10 This is a comparison chart between the measured pressure data and the simulated pressure data of the Huangliu Formation sandstone in Well XX1 in the XX Basin.

[0052] Fig.11 This is a comparison chart of three causes of overpressure.

[0053] Fig.12 It is a histogram of the contribution ratios of the three causes of overpressure to sandstone overpressure.

[0054] Fig.13 It is the numerical model diagram of pressure simulation. Specific implementation method:

[0055] The present invention will be further described below in conjunction with the accompanying drawings:

[0056] This quantitative simulation method for the contribution of sandstone overpressure genesis: collect and organize analysis test, logging, geological and seismic data; analyze the formation pressure characteristics of the target layer sandstone; reconstruct the burial history and thermal history of the target layer sandstone; quantitatively simulate the undercompacted pore pressure evolution history of the target layer sandstone, the pore pressure evolution history of undercompacted and hydrocarbon generation pressurization, and the total pore pressure evolution history; on this basis, quantitatively analyze the contribution of undercompacted, hydrocarbon generation pressurization and other genesis to overpressure, investigate the evolution mechanisms of the three causes of overpressure, and combine Figure 1 , Fig.13 As shown, the details are as follows:

[0057] Step 1) Collect analytical testing, logging, geological and seismic data of target stratum sandstone. The analytical testing data include conventional core analysis, casting thin sections and scanning electron microscope image data, and organic geochemical data; the geological data include drilling stratification data, formation pressure data, formation temperature data, vitrinite reflectance data, and formation age data.

[0058] Step 2) According to the formation pressure data, a formation pressure profile is established, the formation pressure characteristics of the sandstone in the target layer of the target area are analyzed, and a pressure simulation numerical model is established. The pressure simulation numerical model is established based on the actual formation characteristics and actual geological data of the target layer, involving burial history, thermal history and pressure history.

[0059] Step 3) Burial history reconstruction: Based on geological stratification, stratigraphic age data, erosion period and thickness, a one-dimensional burial history of the target layer sandstone is established. The burial history can better reflect the burial process and tectonic evolution stage of the target layer sandstone.

[0060] Step 4) Thermal history reconstruction: The formation temperature data and geothermal gradient data of the target layer sandstone are implanted into the pressure simulation numerical model to reconstruct the thermal history of the target layer sandstone; when the simulated formation temperature value is consistent with the measured formation temperature value, it indicates that the reconstructed thermal history is accurate.

[0061] Step 5) quantitatively simulate the evolution history of undercompacted pore pressure: based on conventional core analysis data, statistically analyze the distribution range and average value of the porosity and permeability of the target layer sandstone and the overburden; input the porosity and permeability of the target layer sandstone into the pressure simulation numerical model, determine the porosity and permeability of the overburden, and quantitatively simulate the evolution history of undercompacted pore pressure.

[0062] Step 6), quantitative simulation of the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization: based on organic geochemical data, investigate the kerogen type, organic carbon and original hydrocarbon generation potential of the underlying source rock of the target layer sandstone; on the basis of quantitative simulation of the pore pressure evolution history of undercompaction, determine the kerogen type of the underlying source rock of the target layer sandstone, input the average value of organic carbon and original hydrocarbon generation potential and the vitrinite reflectance data of the source rock into the pressure simulation numerical model; when the simulated vitrinite reflectance value is consistent with the measured vitrinite reflectance value, it indicates that the quantitative simulation of the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization is accurate.

[0063] The kerogen type of source rocks is determined based on measured organic geochemical data; similarly, organic carbon and original hydrocarbon generation potential data are also determined based on geochemical data.

[0064] On the basis of the undercompacted pore pressure evolution history, the overpressure contribution of hydrocarbon generation in source rocks is considered, and the pore pressure evolution history of undercompacted and hydrocarbon generation pressurization is quantitatively simulated; the pore pressure evolution history of undercompacted, undercompacted and hydrocarbon generation pressurization is combined to obtain the pore pressure evolution history of hydrocarbon generation pressurization.

[0065] P hydrog =P underc+hydrog -P underc

[0066] Where: P underc+hydrog It refers to the pore pressure of undercompaction and hydrocarbon generation pressurization; P underc refers to the undercompacted pore pressure; P hydrog It refers to the pore pressure caused by hydrocarbon generation.

[0067] Step 7), quantitatively simulate the total pore pressure evolution history: based on the measured formation pressure data, analyze the formation pressure characteristics of the target layer sandstone; on the basis of quantitatively simulating the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, use the measured formation pressure data to correct the simulated formation pressure data, and when the measured formation pressure value is consistent with the simulated formation pressure value, quantitatively simulate the total pore pressure evolution history;

[0068] On the basis of the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, the simulated formation pressure data are corrected by using the measured formation pressure data. When the measured formation pressure value is consistent with the simulated formation pressure value, the total pore pressure evolution history is quantitatively simulated. Therefore, on the basis of the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization and the total pore pressure evolution history, the pore pressure of other causes (third cause) is evaluated.

[0069] P other =P total -P underc+hydrog

[0070] Where: P underc+hydrog It refers to the pore pressure of undercompaction and hydrocarbon generation pressurization; P total is the total pore pressure; P other It refers to the pore pressure of other causes (pore pressure of the third cause).

[0071] Step 8) Quantitative analysis of overpressure contribution:

[0072] Pore ​​pressure evolution history of combined undercompaction (P underc ), undercompaction and hydrocarbon generation pressurization pore pressure evolution history (P hydrog ), the total pore pressure evolution history (P total ), when the total pore pressure evolution history is equal to the pore pressure evolution history of undercompaction and hydrocarbon generation, the overpressure of the target layer sandstone is contributed by undercompaction and hydrocarbon generation. By combining the pore pressure evolution history of undercompaction and the pore pressure evolution history of undercompaction and hydrocarbon generation, the undercompaction (P underc ) and hydrocarbon generation pressure (P hydrog ) for total overpressure (P total )’s contribution;

[0073] P total =P underc +P hydrog

[0074] Where: P total is the total pore pressure; P underc refers to the undercompacted pore pressure; P hydrog It refers to the pore pressure caused by hydrocarbon generation.

[0075] When the total pore pressure evolution history is greater than the pore pressure evolution history of undercompaction and hydrocarbon generation, the overpressure of the target layer sandstone is contributed by undercompaction, hydrocarbon generation and other causes. The undercompaction (P underc ), hydrocarbon generation pressure boost (P hydrog ) and other causes (P other ) for total overpressure (P total )’s contribution;

[0076] P total =P underc +P hydrog +P other

[0077] Where: P total is the total pore pressure; P underc refers to the undercompacted pore pressure; P hydrog It refers to the pore pressure of hydrocarbon generation; P other Refers to pore pressure of other causes.

[0078] The present invention combines the pore pressure evolution history of undercompaction, the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, and the total pore pressure evolution history to quantitatively analyze the contributions of undercompaction, hydrocarbon generation pressurization, and abnormal overpressure causes of other genesis.

[0079] The present invention quantitatively simulates the contribution of sandstone overpressure genesis and quantitatively analyzes three overpressure genesis contributions; the specific genesis mechanism of pore pressure of other genesis (third genesis) can be determined in combination with the regional structural characteristics, geological data and seismic data of the study area.

[0080] Embodiment 1:

[0081] This quantitative modeling method for the contribution of sandstone overpressure to the genesis of overpressure includes the following steps:

[0082] (1) Taking the Huangliu Formation in the XX area of ​​the XX basin as an example, analytical testing, logging, geological and seismic data were collected. The analytical testing data included conventional core analysis, casting thin sections and scanning electron microscope image data, and organic geochemical data; the geological data included drilling stratification data, formation pressure data, formation temperature data, vitrinite reflectance data, and formation age data; some formation pressure data are shown in Table 1.

[0083] Table 1 Statistics of formation pressure data of Huangliu Formation

[0084]

[0085]

[0086] (2) Based on the formation pressure data, a formation pressure profile is established to analyze the formation pressure characteristics of the sandstone in the target layer of the target area.

[0087] Attached Figure 2 The relationship between the measured reservoir temperature and depth of the target layer sandstone in the XX basin is shown; the reservoir temperature of the Huangliu Formation in the XX area is distributed in the range of 100.3℃-140.5℃; Figure 3 The cross-section diagram of the measured formation pressure and depth of the target sandstone layer in the XX Basin is displayed; the Huangliu Formation sandstone reservoir is characterized by high temperature, high pressure and under-compaction.

[0088] (3) Burial history reconstruction: Based on geological stratification, stratigraphic age data, erosion period and thickness, the 1D burial history of the target sandstone layer is established; the burial history can better reflect the burial process and tectonic evolution stage of the target sandstone layer.

[0089] Attached Figure 4 The burial history of the Huangliu Formation sandstone in Well XX1 in the XX Basin is shown; the burial history of the sandstone in the target layer can better reflect the sedimentary burial process of the Huangliu Formation sandstone.

[0090] (4) Thermal history reconstruction: Based on the accurate burial history, the formation temperature data and geothermal gradient data of the target layer sandstone are implanted into the numerical model to reconstruct the thermal history of the target layer sandstone; when the simulated formation temperature value is consistent with the measured formation temperature value (see Appendix Figure 5 ), indicating the accuracy of the reconstructed thermal history; Figure 5 The comparison chart of measured temperature value and simulated temperature value of Huangliu Formation sandstone in Well XX1 in XX Basin is shown.

[0091] (5) Quantitative simulation of the evolution history of undercompacted pore pressure: Based on conventional core analysis data, the distribution range and average value of the porosity and permeability of the target sandstone layer and the overburden are statistically analyzed. Some conventional core analysis data are shown in Table 2. Then, in the numerical model, the porosity and permeability of the target sandstone layer are specified in detail, and the porosity and permeability of the overburden are specified to quantitatively simulate the evolution history of undercompacted pore pressure.

[0092] Table 2 Statistical table of physical properties of target sandstone and overburden

[0093] well name Measuring point well depth / m Porosity / % Permeability / mD XX1 2329 14.3 0.24 XX1 2330 14.3 0.24 XX1 2331 14.3 0.24 XX1 2332 14.3 0.24 XX1 2334 14.4 0.25 XX1 2334.5 14.4 0.25 XX1 2335 14.4 0.25 XX1 2334.8 14.4 0.25 XX1 2628 10.4 XX1 2627.5 10.4 XX1 2629 10.4 XX1 2630.5 10.4 XX1 2633 10.2 XX1 2636 11 XX1 2789.8 16 0.52 XX1 2790 16 0.52 XX1 2795.5 17 0.83 XX1 2796.5 16.4 0.63 XX1 2797.5 16.4 0.63 XX1 2806.5 13.1 0.14 XX1 2806.7 13.1 0.14 XX1 2807 13.1 0.14 XX1 2808.5 14.9 0.32 XX1 2796.3 17 0.83 XX1 2796.8 16.4 0.63 XX1 2806.3 13.1 0.14 XX1 2807 13.1 0.14 XX1 2809 15.4 0.4 XX1 2790.5 16 0.52 XX1 3232.5 15.5 0.42 XX1 3233 15.5 0.42 XX1 3232.7 15.5 0.42 XX1 3234 17.5 1.04 XX1 3233.5 17.5 1.04 XX1 3235 15.4 0.4 XX1 3236 15.4 0.4 XX1 3235.5 15.4 0.4 XX1 3235.3 15.4 0.4 XX1 3131 16.1 0.55 XX1 3130 17.8 1.2 XX1 3123.8 14.5 0.26

[0094] The porosity and permeability of the Huangliu Formation sandstone and the overburden are specified in detail, and the pore pressure evolution history of the undercompacted sandstone in the target layer is quantitatively simulated. Figure 6 The evolution history of pore pressure of undercompacted sandstone in the target layer of XX Basin is shown.

[0095] (6) Quantitative simulation of the pore pressure evolution history of undercompaction and hydrocarbon generation: Based on organic geochemical data, the kerogen type, organic carbon and original hydrocarbon generation potential of the underlying source rock of the target sandstone layer were investigated; published literature shows that the shallow marine mudstone of the Miocene Meishan Formation and Sanya Formation is the most important gas source rock for the natural gas reservoir in the XX Basin;

[0096] Attached Figure 7 The kerogen types of underlying source rocks in the XX Basin are displayed. Medium to good grade marine source rocks are developed in the Miocene Meishan Formation and Sanya Formation in the XX Basin, with organic matter types mainly consisting of type II2 to type III, all of which have entered the mature hydrocarbon generation threshold. The Meishan Formation source rocks are superior to those of the Sanya Formation. The Sanya Formation and Meishan Formation source rocks in the Oriental area show early gas generation and long duration.

[0097] Then, on the basis of the undercompacted pore pressure evolution history, the kerogen type, organic carbon and original hydrocarbon generation potential of the underlying source rock of the target layer sandstone are specified in detail, and the vitrinite reflectance data of the source rock are implanted; when the simulated vitrinite reflectance value is consistent with the measured vitrinite reflectance value, it indicates the accuracy of the quantitative simulation of the undercompacted and hydrocarbon-generated pore pressure evolution history; Figure 8 The pore pressure evolution history of undercompaction and hydrocarbon generation pressurization of the Huangliu Formation sandstone in Well XX1 in the XX Basin is shown.

[0098] (7) Quantitative simulation of the total pore pressure evolution history: Based on the measured formation pressure data, analyze the formation pressure characteristics of the target layer sandstone; based on the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, use the measured formation pressure data to correct the simulated formation pressure data. When the measured formation pressure value is consistent with the simulated formation pressure value, the total pore pressure evolution history is quantitatively simulated; Fig. 9 The overall pore pressure evolution history of the Huangliu Formation sandstone in Well XX1 in the XX Basin is shown; Fig.10 A comparison chart of the measured pressure data and simulated pressure data of the Huangliu Formation sandstone in Well XX1 in the XX Basin is shown; overpressure (pressure coefficient greater than 1.2) began to form in the first and second sections of the Huangliu Formation in Well XX1 at around 5.2Ma and 5.3Ma, respectively, and the pressure coefficients increased to 2.05 and 1.97, respectively, with increasing burial depth.

[0099] (8) Quantitative analysis of overpressure contribution: Combine the pore pressure evolution history of undercompaction, the pore pressure evolution history of undercompaction and hydrocarbon generation, and the total pore pressure evolution history. When the total pore pressure evolution history is greater than the pore pressure evolution history of undercompaction and hydrocarbon generation, the overpressure of the target sandstone is contributed by undercompaction, hydrocarbon generation, and other causes. Combine the pore pressure evolution history of undercompaction, the pore pressure evolution history of undercompaction and hydrocarbon generation, and the total pore pressure evolution history to quantitatively analyze the contribution of undercompaction, hydrocarbon generation, and other causes to the total overpressure.

[0100] Attached Fig.11 A comparison of the three causes of overpressure is shown; Fig.12 The histogram of the contribution ratio of the three causes of overpressure to the sandstone overpressure is shown; the overpressure of the Huangliu Formation sandstone in Well XX1 is mainly composed of undercompaction, hydrocarbon generation pressurization, montmorillonite-illite transformation and overpressure transmission.

Claims

1. A quantitative simulation method for the contribution of sandstone overpressure genesis, characterized in that The steps include: Step 1) Collect the analytical test, logging, geological and seismic data of the target layer sandstone. The analytical test data include conventional core analysis, casting thin section and scanning electron microscope image data, organic geochemical data; the geological data include drilling layer data, formation pressure data, formation temperature data, vitrinite reflectance data, and formation age data; Step 2) According to the formation pressure data, a formation pressure profile is established, the formation pressure characteristics of the sandstone in the target layer of the target area are analyzed, and a pressure simulation numerical model is established. The pressure simulation numerical model is established based on the actual formation characteristics and actual geological data of the target layer, involving burial history, thermal history and pressure history; Step 3) Burial history reconstruction: Based on geological stratification, stratigraphic age data, denudation period and thickness, establish the one-dimensional burial history of the target layer sandstone; Step 4), thermal history reconstruction: implant the formation temperature data and geothermal gradient data of the target layer sandstone into the pressure simulation numerical model to reconstruct the thermal history of the target layer sandstone; when the simulated formation temperature value is consistent with the measured formation temperature value, it indicates that the reconstructed thermal history is accurate; Step 5), quantitatively simulate the evolution history of undercompacted pore pressure: Based on conventional core analysis data, the distribution range and average value of porosity and permeability of target sandstone and overburden are statistically analyzed; the porosity and permeability of target sandstone are input into the pressure simulation numerical model to determine the porosity and permeability of overburden, and quantitatively simulate the evolution history of undercompacted pore pressure; Step 6), quantitatively simulate the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization: Based on organic geochemical data, the kerogen type, organic carbon and original hydrocarbon generation potential of the underlying source rock of the target layer sandstone are investigated; on the basis of quantitative simulation of the undercompacted pore pressure evolution history, the kerogen type of the underlying source rock of the target layer sandstone is determined, and the average values ​​of organic carbon and original hydrocarbon generation potential and the vitrinite reflectance data of the source rock are input into the pressure simulation numerical model; when the simulated vitrinite reflectance value is consistent with the measured vitrinite reflectance value, it indicates that the quantitative simulation of the undercompacted and hydrocarbon-generated pore pressure evolution history is accurate; The pore pressure evolution history of undercompaction and the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization are combined to obtain the pore pressure evolution history of hydrocarbon generation pressurization. P hydrog =P underc+hydrog -P underc Where: P underc+hydrog It refers to the pore pressure of undercompaction and hydrocarbon generation pressurization; P underc refers to the undercompacted pore pressure; P hydrog It refers to the pore pressure caused by hydrocarbon generation. Step 7), quantitatively simulate the total pore pressure evolution history: Analyze the formation pressure characteristics of the target sandstone layer based on the measured formation pressure data; On the basis of quantitatively simulating the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, the measured formation pressure data are used to correct the simulated formation pressure data. When the measured formation pressure value is consistent with the simulated formation pressure value, the total pore pressure evolution history is quantitatively simulated. Based on the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, and the total pore pressure evolution history, the pore pressure of other origins is evaluated; P other =P total -P underc+hydrog Where: P underc+hydrog It refers to the pore pressure of undercompaction and hydrocarbon generation pressurization; P total is the total pore pressure; P other It refers to pore pressure of other causes; Step 8), quantitative analysis of overpressure genesis contribution: when the total pore pressure evolution history is greater than the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, the overpressure of the target layer sandstone is contributed by undercompaction, hydrocarbon generation pressurization and the third cause, and the contribution of undercompaction, hydrocarbon generation pressurization and the third cause to the total overpressure is quantitatively analyzed; when the total pore pressure evolution history is equal to the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, the overpressure of the target layer sandstone is contributed by two causes, undercompaction and hydrocarbon generation pressurization, and the contribution of undercompaction and hydrocarbon generation pressurization to the total overpressure is quantitatively analyzed.

2. A quantitative simulation method for the genetic contribution of sandstone overpressure according to claim 1, characterized in that: The quantitative analysis of the contribution of the overpressure formation is as follows: Pore ​​pressure evolution history of combined undercompaction underc The evolution history of pore pressure due to undercompaction and hydrocarbon generation hydrog , the total pore pressure evolution history P total When the total pore pressure evolution history is equal to the pore pressure evolution history of undercompaction and hydrocarbon generation, the overpressure of the target layer sandstone is contributed by both undercompaction and hydrocarbon generation. By combining the pore pressure evolution history of undercompaction and the pore pressure evolution history of undercompaction and hydrocarbon generation, the undercompaction P underc and hydrocarbon generation pressure P hydrog Total overpressure P total Contribution P total =P underc +P hydrog Where: P total is the total pore pressure; P underc refers to the undercompacted pore pressure; P hydrog It refers to the pore pressure caused by hydrocarbon generation. When the total pore pressure evolution history is greater than the pore pressure evolution history of undercompaction and hydrocarbon generation, the overpressure of the target layer sandstone is contributed by undercompaction, hydrocarbon generation and other causes. The undercompaction P is quantitatively analyzed by combining the pore pressure evolution history of undercompaction, the pore pressure evolution history of undercompaction and hydrocarbon generation, and the total pore pressure evolution history. underc 、Hydrocarbon generation and pressure boosting P hydrog and other causes other Total overpressure P total Contribution P total =P underc +P hydrog +P other Where: P total is the total pore pressure; P underc refers to the undercompacted pore pressure; P hydrog It refers to the pore pressure of hydrocarbon generation; P other Refers to pore pressure of other causes.

3. A quantitative simulation method for the contribution of sandstone overpressure genesis, characterized in that The steps include: Step 1) Collect the analytical test, logging, geological and seismic data of the target layer sandstone. The analytical test data include conventional core analysis, casting thin section and scanning electron microscope image data, organic geochemical data; the geological data include drilling layer data, formation pressure data, formation temperature data, vitrinite reflectance data, and formation age data; Step 2) According to the formation pressure data, a formation pressure profile is established, the formation pressure characteristics of the sandstone in the target layer of the target area are analyzed, and a pressure simulation numerical model is established. The pressure simulation numerical model is established based on the actual formation characteristics and actual geological data of the target layer, involving burial history, thermal history and pressure history; Step 3) Burial history reconstruction: Based on geological stratification, stratigraphic age data, denudation period and thickness, establish the one-dimensional burial history of the target layer sandstone; Step 4), thermal history reconstruction: implant the formation temperature data and geothermal gradient data of the target layer sandstone into the pressure simulation numerical model to reconstruct the thermal history of the target layer sandstone; when the simulated formation temperature value is consistent with the measured formation temperature value, it indicates that the reconstructed thermal history is accurate; Step 5), quantitatively simulate the evolution history of undercompacted pore pressure: According to the burial history and thermal history of the target sandstone, determine the oil and gas system where the target sandstone is located, including source rock, reservoir and cap rock; The porosity-depth relationship chart and porosity-permeability relationship chart of the target layer sandstone and multiple sets of caprocks are carefully prepared, and these two charts are embedded in the pressure simulation numerical model as constraints to quantitatively simulate the under-compacted pore pressure evolution history of the target layer sandstone; Step 6), quantitatively simulate the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization: Based on organic geochemical data, the kerogen type, organic carbon and original hydrocarbon generation potential of the underlying source rock of the target layer sandstone are investigated; on the basis of quantitative simulation of the undercompacted pore pressure evolution history, the kerogen type of the underlying source rock of the target layer sandstone is determined, and the average values ​​of organic carbon and original hydrocarbon generation potential and the vitrinite reflectance data of the source rock are input into the pressure simulation numerical model; when the simulated vitrinite reflectance value is consistent with the measured vitrinite reflectance value, it indicates that the quantitative simulation of the undercompacted and hydrocarbon-generated pore pressure evolution history is accurate; The pore pressure evolution history of undercompaction and the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization are combined to obtain the pore pressure evolution history of hydrocarbon generation pressurization. P hydrog =P underc+hydrog -P underc Where: P underc+hydrog It refers to the pore pressure of undercompaction and hydrocarbon generation pressurization; P underc refers to the undercompacted pore pressure; P hydrog It refers to the pore pressure caused by hydrocarbon generation. Step 7), quantitatively simulate the total pore pressure evolution history: Analyze the formation pressure characteristics of the target sandstone layer based on the measured formation pressure data; On the basis of quantitatively simulating the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, the measured formation pressure data are used to correct the simulated formation pressure data. When the measured formation pressure value is consistent with the simulated formation pressure value, the total pore pressure evolution history is quantitatively simulated. Based on the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, and the total pore pressure evolution history, the pore pressure of other origins is evaluated; P other =P total -P underc+hydrog Where: P underc+hydrog It refers to the pore pressure of undercompaction and hydrocarbon generation pressurization; P total is the total pore pressure; P other It refers to pore pressure of other causes; Step 8), quantitative analysis of overpressure genesis contribution: when the total pore pressure evolution history is greater than the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, the overpressure of the target layer sandstone is contributed by undercompaction, hydrocarbon generation pressurization and the third cause, and the contribution of undercompaction, hydrocarbon generation pressurization and the third cause to the total overpressure is quantitatively analyzed; when the total pore pressure evolution history is equal to the pore pressure evolution history of undercompaction and hydrocarbon generation pressurization, the overpressure of the target layer sandstone is contributed by two causes, undercompaction and hydrocarbon generation pressurization, and the contribution of undercompaction and hydrocarbon generation pressurization to the total overpressure is quantitatively analyzed.

4. The quantitative simulation method of sandstone overpressure contribution according to claim 3, characterized in that: The quantitative analysis of the contribution of the overpressure formation is as follows: Pore ​​pressure evolution history of combined undercompaction underc The evolution history of pore pressure due to undercompaction and hydrocarbon generation hydrog , the total pore pressure evolution history P total When the total pore pressure evolution history is equal to the pore pressure evolution history of undercompaction and hydrocarbon generation, the overpressure of the target layer sandstone is contributed by both undercompaction and hydrocarbon generation. By combining the pore pressure evolution history of undercompaction and the pore pressure evolution history of undercompaction and hydrocarbon generation, the undercompaction P underc and hydrocarbon generation pressure P hydrog Total overpressure P total Contribution P total =P underc +P hydrog Where: P total is the total pore pressure; P underc refers to the undercompacted pore pressure; P hydrog It refers to the pore pressure caused by hydrocarbon generation. When the total pore pressure evolution history is greater than the pore pressure evolution history of undercompaction and hydrocarbon generation, the overpressure of the target layer sandstone is contributed by undercompaction, hydrocarbon generation and other causes. The undercompaction P is quantitatively analyzed by combining the pore pressure evolution history of undercompaction, the pore pressure evolution history of undercompaction and hydrocarbon generation, and the total pore pressure evolution history. underc 、Hydrocarbon generation and pressure boosting P hydrog and other causes other Total overpressure P total Contribution P total =P underc +P hydrog +P other Where: P total is the total pore pressure; P underc refers to the undercompacted pore pressure; P hydrog It refers to the pore pressure of hydrocarbon generation; P other Refers to pore pressure of other causes.

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