A construction extrusion pressurization evaluation method based on the idea of dynamic evolution

Abstract

The present invention discloses a method for evaluating structural extrusion pressurization based on the idea of dynamic evolution. By using the variation relationship between pressure data and logging data with burial depth, the normal compaction section and the overpressure section are comprehensively judged; the evolution paths of the acoustic velocity and density of mudstone in the normal compaction section of the structural extrusion area before and after the structural extrusion are reconstructed to determine the density of mudstone in the normal compaction section under only vertical stress without structural extrusion in the structural extrusion area; the evolution paths of the acoustic velocity and density of mudstone in the overpressure section of the structural extrusion area before and after the structural extrusion are reconstructed to determine the density corresponding to the overpressure section in the structural extrusion area under only vertical stress without structural extrusion; a relationship model between the density and the vertical effective stress of mudstone in the normal compaction section of the structural extrusion area under two conditions of only vertical stress without structural extrusion and structural extrusion is established. Combining the variation law of mudstone in the overpressure section on the relationship chart before and after structural extrusion compaction and structural extrusion pressurization, the magnitude of structural extrusion pressurization in the overpressure layer section is quantitatively calculated.

Description

Technical Field

[0001] The present invention relates to the field of oil and gas exploration and development, and particularly relates to a method for evaluating tectonic extrusion pressurization based on the idea of dynamic evolution. Background Art

[0002] At present, overpressure generally exists in oil and gas reservoirs. During its formation process, it has experienced strong tectonic extrusion, and tectonic extrusion has an important impact on the formation of its overpressure. At present, although there are various prediction methods for tectonic extrusion pressurization, such as Luo Xiaorong (2004) [1] , Zhang Fengqi et al. (2011) [2] , Zhang Fengqi et al. (2020) [3] , Zhang et al. (2021) [4] , Fan et al. (2021) [5] , Wang Bing et al. (2022) [6] etc., but since the formation of overpressure in the foreland thrust belt not only contributes to tectonic extrusion pressurization, but also contributes to other overpressure mechanisms such as undercompaction and overpressure transfer, and it is often composed of multiple mechanisms, making the quantitative evaluation of tectonic extrusion pressurization extremely difficult. The existing evaluation methods for tectonic extrusion pressurization are mostly dynamic evolution evaluations by numerical simulation or static evaluations in the current period based on logging and geological data. When conducting dynamic evolution evaluations by numerical simulation, many parameters are difficult to determine, and it is difficult to accurately evaluate the magnitude of tectonic extrusion pressurization in the composite composition based on the static evaluation in the current period. Therefore, a new method is needed to evaluate the magnitude of tectonic extrusion pressurization in the multi-mechanism composite composition.

[0003] [1] Luo Xiaorong. Quantitative analysis of the overpressure mechanism of tectonic stress. Chinese Journal of Geophysics, 2004, 47(6): 1086 - 1093.

[0004] [2] Zhang Fengqi, Wang Zhenliang, Song Yan, Zhao Mengjun, Liu Shaobo, Fang Shihu. A new method for quantitatively evaluating tectonic extrusion pressurization in the Kuqa Depression. Journal of China University of Petroleum, 2011, 35(4): 1 - 7.

[0005] [3] Zhang Fengqi, Lu Xuesong, Zhuo Qingong, Zhong Hongli, Zhang Pei, Wei Chi, Liu Wei. Genesis mechanism and evolution characteristics of abnormal high pressure in the lower combination reservoirs in the southern margin of the Junggar Basin. Oil & Gas Geology, 2020, 41(5): 2004 - 2015.

[0006] [4] Fengqi Zhang, Xuesong Lu, Scott Botterill, Murray Gingras, Qingong Zhuo, Hongli Zhong. Horizontal tectonic stress as a cause of overpressure in the southern margin of the Junggar Basin, northwest China. Journal of Petroleum Science and Engineering, 2021, 205, 108861.

[0007] [5] Changyu Fan, Gang Wang, Zhenliang Wang, Xiaojie Han, Jie Chen, Kuaile Zhang, Baoshou Zhang. Prediction of multiple origin overpressure in deep fold-thrust belt: A case study of Kuqa subbasin, Tarim Basin, northwestern China. AAPG Bulletin, 2021, 105(8): 1511-1533.

[0008] [6] Wang Bing, Qiu Nansheng, Wang Xiang, Zhang Haizu, Liu Yifeng, Chang Jian, Zhu Chuanqing. Identification and calculation of tectonic compression overpressure in the Kelasu-Yiqikelike tectonic belt of the Kuqa Depression. Acta Petrolei Sinica, 2022, 43(8): 1107-1121. Summary of the Invention

[0009] The purpose of the present invention is to provide a tectonic compression pressurization evaluation method based on the idea of dynamic evolution to overcome the defects existing in the prior art. The present invention has the characteristics of being more practical, novel in idea, and more accurate, and provides a new method for accurately evaluating the tectonic compression pressurization of multi-mechanism composite overpressure in the foreland thrust belt.

[0010] To achieve the above purpose, the present invention adopts the following technical solutions:

[0011] A tectonic compression pressurization evaluation method based on the idea of dynamic evolution, comprising the following steps:

[0012] Step 1: Organize the pressure data and logging data. The pressure data includes the measured formation pressure coefficient, the formation pressure coefficient measured while drilling, and the mud density. The logging data includes the acoustic time difference, density, and resistivity of mudstone at different burial depths.

[0013] Step 2: Use the data of acoustic time difference, density, and resistivity of mudstones at different burial depths sorted out in Step 1, as well as the variation relationships of formation pressure coefficient, mud density, and measured formation pressure coefficient with burial depth during drilling, to comprehensively judge the normally compacted section and overpressure section;

[0014] Step 3: Reconstruct the evolution paths of acoustic velocity and density of mudstones in the normally compacted section of the tectonic compression area before and after tectonic compression, and determine the acoustic velocity and density of mudstones in the normally compacted section under only vertical stress without tectonic compression in the tectonic compression area;

[0015] Step 4: Reconstruct the evolution paths of acoustic velocity and density of mudstones in the overpressure section of the tectonic compression area before and after tectonic compression, and determine the acoustic velocity and density corresponding to the overpressure section in the tectonic compression area under only vertical stress without tectonic compression;

[0016] Step 5: Use the results of Step 3 and Step 4 to quantitatively calculate the magnitude of tectonic compression-induced overpressure in the overpressure interval.

[0017] Further, the specific content of Step 3 is as follows:

[0018] Use the normally compacted section determined in Step 2 to select typical wells in the tectonic compression area and the area without tectonic compression, and use logging density data to respectively establish quantitative models of the average effective stress in the normally compacted section under two conditions: tectonic compression in the tectonic compression area and only vertical stress without tectonic compression, and obtain the average effective stress in the normally compacted section under the two conditions;

[0019] Use logging density data to respectively establish relationship models between density porosity and density of mudstones in the normally compacted section in the tectonic compression area and the area without tectonic compression, and obtain the density porosity of mudstones in the normally compacted section;

[0020] Use logging acoustic time difference data to respectively establish relationship models between acoustic porosity and acoustic time difference of mudstones in the normally compacted section in the tectonic compression area and the area without tectonic compression, and obtain the acoustic porosity of mudstones in the normally compacted section;

[0021] Establish a relationship model between the acoustic porosity and the mean effective stress of mudstone in the normal compaction section of the tectonic compression area. Combine it with the mean effective stress in the normal compaction section under the action of only vertical stress without tectonic compression in the tectonic compression area to obtain the acoustic porosity of mudstone in the normal compaction section under the action of only vertical stress without tectonic compression. Further combine it with the relationship model between the acoustic porosity and acoustic travel time and the relationship model between the density porosity and density of mudstone in the normal compaction section of the non-tectonic compression area to respectively obtain the acoustic travel time and the density of mudstone in the normal compaction section under the action of only vertical stress without tectonic compression in the tectonic compression area. Utilize the reciprocal relationship between the sound velocity and the acoustic travel time to obtain the acoustic velocity of mudstone in the normal compaction section under the action of only vertical stress without tectonic compression in the tectonic compression area, and establish a relationship model between the acoustic velocity and density in the normal compaction section under the action of only vertical stress without tectonic compression in the tectonic compression area;

[0022] Utilize the acoustic travel time measured by well logging in the tectonic compression area to obtain the acoustic velocity, and establish a relationship model between the acoustic velocity and density in the normal compaction section under the action of tectonic compression in the tectonic compression area; Combine this relationship model with the relationship model between the acoustic velocity and density in the normal compaction section under the action of only vertical stress without tectonic compression in the tectonic compression area, so as to reconstruct the evolution path of the acoustic velocity and density of mudstone in the normal compaction section of the tectonic compression area before and after the action of tectonic compression, and obtain the acoustic velocity and density of mudstone in the normal compaction section under the action of only vertical stress without tectonic compression in the tectonic compression area.

[0023] Furthermore, step 3 specifically includes the following steps:

[0024] Step 3.1: Establish a mean effective stress model in the normal compaction section under the action of only vertical stress without tectonic compression, as shown in the following formula:

[0025]

[0026] Wherein, is the mean effective stress in the normal compaction section under the action of only vertical stress without tectonic compression, σ v1 is the vertical load stress under the action of only vertical stress without tectonic compression, ν is the stress ratio coefficient, ρ w is the formation water density, g is the acceleration due to gravity, and h is the burial depth;

[0027] The vertical load stress σ v1 under the action of only vertical stress without tectonic compression is further expressed as:

[0028]

[0029] Wherein, ρ(h) is a density function varying with depth, expressed as:

[0030] ρ(h) = a·h b

[0031] Among them, a and b are fitting coefficients obtained from the power function relationship between the logging density and burial depth of wells in the non-structural extrusion area. Substitute ρ(h) into σ v1 and the average effective stress model of the normal compaction section under the action of only vertical stress without structural extrusion is further expressed as:

[0032]

[0033] Step 3.2: Establish the average effective stress model of normal compaction under the action of structural extrusion, as shown in the following formula:

[0034]

[0035] Among them, is the average effective stress of normal compaction under the action of structural extrusion, and σ v2 is the vertical load stress under the action of structural extrusion. Its expression is shown in Step 3.1. Different from it, the x and y coefficients need to be obtained by fitting the power function relationship between the logging density and burial depth under the action of structural extrusion in the structural extrusion area. σ T is the structural extrusion stress;

[0036] The structural extrusion stress σ T is a function of burial depth in the shallow part. If the burial depth is greater than the given depth, it is a fixed value, expressed as:

[0037]

[0038] Among them, σ Tmax is the maximum tectonic stress, z is the burial depth, and z m is the given depth, and c is a constant;

[0039] Step 3.3: Establish the relationship model between the density porosity and density of mudstone in the normal compaction section of the structural extrusion area and the non-structural extrusion area, as shown in the following formula:

[0040]

[0041] Among them, Φ density is the density porosity, ρ ma is the density of the matrix, ρ f is the density of formation water, and ρ b is the density obtained by logging;

[0042] Step 3.4: Establish the relationship model between the acoustic porosity and acoustic travel time of mudstone in the normal compaction section of the structural extrusion area and the non-structural extrusion area, as shown in the following formula:

[0043]

[0044] Among them, Φsonic is the acoustic porosity, Δt f is the acoustic travel time of formation water, Δt ma is the acoustic travel time of matrix, Δt is the acoustic travel time obtained from logging, C p is the proportionality coefficient between acoustic porosity and density porosity;

[0045] Step 3.5: Using the average effective stress obtained in Step 3.2 and the acoustic porosity obtained in Step 3.4, establish a relationship model between the acoustic porosity of mudstone in the normal compaction section of the tectonic compression area and its average effective stress, as shown in the following formula:

[0046]

[0047] where, Φ sonic is the acoustic porosity, is the average effective stress, d and f are constants obtained by fitting the average effective stress and acoustic porosity of the normal compaction section of the actual well under the action of only vertical stress without tectonic compression in Step 3.2 and Step 3.4 respectively;

[0048] Step 3.6: Substitute the average effective stress of the normal compaction section of the actual well obtained in Step 3.1 under the action of only vertical stress without tectonic compression into the formula in Step 3.5 to obtain the acoustic porosity of mudstone in the normal compaction section under the action of only vertical stress without tectonic compression. Further combine it with the relationship model between density porosity and density in Step 3.3 and the relationship model between acoustic porosity and acoustic travel time in Step 3.4 to respectively obtain the acoustic travel time and density of mudstone in the normal compaction section at different burial depths under the action of only vertical stress without tectonic compression in the tectonic compression area. Using the reciprocal relationship between sound velocity and acoustic travel time, obtain the acoustic velocity of mudstone in the normal compaction section at different burial depths under the action of only vertical stress without tectonic compression in the tectonic compression area. Further establish an exponential relationship model between the acoustic velocity and density of the normal compaction section under the action of only vertical stress without tectonic compression in the tectonic compression area, as shown in the following formula:

[0049]

[0050] where, V sonic is the acoustic velocity, ρ b is the density obtained from logging, w and i are constants obtained by fitting the acoustic velocity and density of the normal compaction section of the actual well under the action of only vertical stress without tectonic compression. The relationship model between the acoustic velocity and density of the normal compaction section under the action of tectonic compression in the tectonic compression area is similar to the exponential relationship model between the acoustic velocity and density of the normal compaction section under the action of only vertical stress without tectonic compression in the tectonic compression area, only replacing the w and i constants with the constants obtained by fitting the acoustic velocity and density from the logging data of the actual well in the tectonic compression area;

[0051] Compare the acoustic velocity and density of mudstone in the normally compacted section at the same burial depth under two conditions: only vertical stress without tectonic compression and tectonic compression, so as to reconstruct the evolution path of mudstone in the normally compacted section of the tectonic compression area from the starting point to the ending point under the action of tectonic compression.

[0052] Further, the specific content of step 4 is as follows:

[0053] Substitute the normal compaction density corresponding to the overpressure section under the action of tectonic compression into the exponential relationship model of acoustic velocity and density of the normally compacted section under the action of tectonic compression established in step 3.6 to obtain the normal compaction acoustic velocity corresponding to the overpressure section under the action of tectonic compression;

[0054] Use the acoustic velocity and density of mudstone obtained by logging in the overpressure section under the action of tectonic compression and the acoustic velocity and density of the corresponding normally compacted section to establish a linear relationship model between these two points, and find the intersection point of the linear relationship model of this overpressure section and the exponential relationship model of acoustic velocity and density of mudstone in the normally compacted section under only vertical stress without tectonic compression to obtain the acoustic velocity and density under only vertical stress without tectonic compression corresponding to the overpressure section under the action of tectonic compression;

[0055] Compare the acoustic velocity and density of mudstone in the overpressure section at the same burial depth under two conditions: only vertical stress without tectonic compression and tectonic compression, so as to reconstruct the evolution path of the acoustic velocity and density of mudstone in the overpressure section of the tectonic compression area before and after the action of tectonic compression, and obtain the acoustic velocity and density under only vertical stress without tectonic compression corresponding to the overpressure section of the tectonic compression area.

[0056] Further, the specific content of step 5 is as follows:

[0057] Use the logging density data to establish a quantitative model of the vertical effective stress in the normally compacted section under the action of tectonic compression and only vertical stress without tectonic compression in the tectonic compression area, obtain the vertical effective stress under only vertical stress without tectonic compression in the tectonic compression area, combine it with the density of mudstone in the normally compacted section under only vertical stress without tectonic compression determined by step 3 to establish a relationship model between the density of mudstone in the normally compacted section and the vertical effective stress under only vertical stress without tectonic compression in the tectonic compression area, combine it with the density under only vertical stress without tectonic compression corresponding to the overpressure section of the tectonic compression area obtained in step 4 to obtain the vertical effective stress under only vertical stress without tectonic compression corresponding to the overpressure section of the tectonic compression area, and compare the vertical stress difference of this overpressure section under two conditions of tectonic compression and only vertical stress without tectonic compression to obtain the vertical effective stress of this overpressure section after tectonic compaction;

[0058] Using the density and vertical effective stress data of mudstone in the normal compaction section under tectonic extrusion, establish a relationship model between the two, and combine it with the density of the adjacent mudstone in the overpressure section under tectonic extrusion to obtain the corresponding vertical effective stress after the overpressure section experiences tectonic extrusion and pressure increase;

[0059] Subtract the vertical effective stress of the same overpressure section after tectonic extrusion compaction from the corresponding vertical effective stress after experiencing tectonic extrusion and pressure increase, and the tectonic extrusion and pressure increase of the overpressure section can be obtained.

[0060] Further, step 5 specifically includes the following steps:

[0061] Step 5.1: Establish a quantitative model of the vertical effective stress in the normal compaction section under tectonic extrusion and under the action of only vertical stress without tectonic extrusion in the tectonic extrusion area, as shown in the following formula:

[0062] δ = σ v -P 静 = σ v -ρ 水 ·g·h

[0063] Where, δ is the vertical effective stress, σ v is the vertical load stress. In the case of tectonic extrusion, σ v is the same as the above-mentioned σ v2 . Under the action of only vertical stress without tectonic extrusion, σ v is the same as the above-mentioned σ v1 . P 静 is the formation hydrostatic pressure, ρ 水 is the formation water density, g is the acceleration of gravity, and h is the burial depth;

[0064] Step 5.2: Combine the vertical effective stress of the mudstone in the normal compaction section under the action of only vertical stress without tectonic extrusion obtained in step 5.1 with the density of the mudstone in the normal compaction section under the action of only vertical stress without tectonic extrusion determined by using step 3 in this well, and establish a relationship model between the density and vertical effective stress of the mudstone in the normal compaction section under the action of only vertical stress without tectonic extrusion in the tectonic extrusion area, as shown in the following formula:

[0065]

[0066] Where, ρ b无 is the density of the mudstone under the action of only vertical stress without tectonic extrusion, δ 无 is the vertical effective stress under the action of only vertical stress without tectonic extrusion, and k and m are the fitting coefficients of the density and vertical effective stress of the mudstone in the normal compaction section under the action of only vertical stress without tectonic extrusion in the actual well;

[0067] Step 5.3: Combine the relationship model between the shale density and the vertical effective stress in the normal compaction section under the action of only vertical stress without tectonic extrusion in the actual well structure extrusion area established in Step 5.2 with the density under the action of only vertical stress corresponding to the overpressure section of this actual well obtained in Step 4 to obtain the vertical effective stress under the action of only vertical stress corresponding to the overpressure section of this well without tectonic extrusion. Compare the vertical stress differences in the overpressure section under the two conditions of tectonic extrusion and only vertical stress without tectonic extrusion to obtain the vertical effective stress after tectonic extrusion compaction in the overpressure section;

[0068] Step 5.4: Use the shale density and vertical effective stress data in the normal compaction section under tectonic extrusion of the actual well to establish a relationship model between the two as shown in the following formula:

[0069]

[0070] where ρ b有 is the shale density under the action of tectonic extrusion, δ 有 is the vertical effective stress under the action of tectonic extrusion, and n and q are the fitting coefficients of the shale density and vertical effective stress in the normal compaction section under the action of tectonic extrusion of the actual well;

[0071] Substitute the density of the shale adjacent to the overpressure section of the actual well in the tectonic extrusion area into this formula to obtain the vertical effective stress corresponding to the overpressure section after experiencing tectonic extrusion pressure increase. When the calculated vertical effective stress corresponding to the overpressure section after experiencing tectonic extrusion pressure increase is greater than or equal to the vertical effective stress obtained from the measured pressure of this overpressure section, subtract the vertical effective stress after tectonic extrusion compaction of the same overpressure section obtained in Step 5.3 from the vertical effective stress after experiencing tectonic extrusion pressure increase of the same layer obtained in this step, that is, obtain the tectonic extrusion pressure increase of this overpressure section. When the calculated vertical effective stress corresponding to the overpressure section after experiencing tectonic extrusion pressure increase is less than the vertical effective stress obtained from the measured pressure of this overpressure section, subtract the vertical effective stress after tectonic extrusion compaction of this overpressure section from the vertical effective stress obtained from the measured pressure of this overpressure section, that is, obtain the tectonic extrusion pressure increase of this overpressure section.

[0072] Compared with the prior art, the present invention has the following beneficial technical effects:

[0073] Foreland basin thrust belts at home and abroad are rich in oil and gas resources and still have great exploration potential. At present, overpressure commonly exists in the discovered oil and gas reservoirs within them. During their formation process, they have experienced strong tectonic squeezing, and tectonic squeezing has an important influence on the formation and evolution of their overpressure. In addition, during the process of tectonic squeezing and pressure increase, there are also pressure increase effects caused by other mechanisms such as undercompaction and overpressure transfer, which makes the quantitative evaluation of tectonic squeezing and pressure increase extremely difficult. The existing evaluation methods for tectonic squeezing and pressure increase are mostly static evaluations based on the current period and dynamic evolution evaluations based on numerical simulations. However, many parameters are difficult to determine during the dynamic evolution evaluation by numerical simulation, and the static evaluation based on the current period is difficult to accurately evaluate the magnitude of tectonic squeezing and pressure increase in the composite structure. Based on the differential change characteristics of well logging responses and rock deformation during the two actual process stages experienced during tectonic squeezing: the tectonic squeezing compaction stage and the tectonic squeezing and pressure increase stage, the present invention establishes a relationship model between the key well logging series acoustic time difference (the reciprocal of acoustic velocity), density, and the mean effective stress and vertical effective stress that are closely related to rock deformation and overpressure, which describe these two evolution stages. Finally, the quantitative evaluation of the magnitude of tectonic squeezing and pressure increase based on the actual geological evolution process is realized, thus more reasonably and skillfully separating it from other pressure increase mechanisms such as undercompaction and overpressure transfer. Therefore, the tectonic squeezing and pressure increase obtained by this evaluation method is more reasonable and accurate. In short, the present invention has the characteristics of being more in line with reality, novel in thinking, more reasonable, and more accurate, and can provide a new method for the accurate evaluation of tectonic squeezing and pressure increase in the overpressure composed of multiple mechanisms in the foreland thrust belt. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 It is a schematic flow chart of the present invention.

[0075] Figure 2 It is an identification diagram of the normal compaction section and overpressure section of Well S1, and it is a relationship diagram of acoustic time difference, density, formation resistivity, mud density, and formation pressure coefficient measured while drilling with burial depth.

[0076] Figure 3 It is an identification diagram of the normal compaction section and overpressure section of Well S2, and it is a relationship diagram of acoustic time difference, density, and formation resistivity with burial depth.

[0077] Figure 4 It is a relationship diagram between the mean effective stress and acoustic porosity of Well S1.

[0078] Figure 5 It is a schematic diagram of the evolution path of the acoustic velocity and density of mudstone in the normal compaction section of Well S1 before and after tectonic squeezing.

[0079] Figure 6 It is a schematic diagram of the evolution path of the acoustic velocity and density of mudstone in the overpressure section of Well S1 before and after tectonic squeezing.

[0080] Figure 7 It is a schematic diagram for calculating structural extrusion boost using vertical effective stress and density in Well S1. Specific implementation mode

[0081] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0082] Taking Well S1 in the structural extrusion area on the southern margin of the Junggar Basin and Well S2 in the non-structural extrusion area in the abdomen of the Junggar Basin as examples, a method for evaluating structural extrusion boost based on the idea of dynamic evolution includes the following steps:

[0083] Step 1: Collect and sort out pressure data such as the measured formation pressure coefficient, formation pressure coefficient measured while drilling, and mud density of actual wells S1 and S2, and logging data such as acoustic time difference, density, and resistivity.

[0084] Step 2: Use the logging data of actual wells S1 and S2 to read the average acoustic time difference, average density, and average resistivity of the mudstone section with a thickness greater than 5 m, and use the data to respectively compile the variation curves of the average acoustic time difference, average density, and average resistivity with depth. Use the fact that both the average density and average resistivity show negative anomalies, the average acoustic time difference shows a positive anomaly, and combine the variation relationships of the formation pressure coefficient measured while drilling and the mud density with the burial depth respectively to comprehensively judge the normally compacted section and the overpressure section. It is comprehensively judged that the normally compacted sections of Well S1 and Well S2 are above 3043 m and 3459 m respectively, and the overpressure sections are below 3043 m and 3459 m respectively ( Figure 2 and Figure 3 );

[0085] Step 3: Reconstruct the evolution paths of the acoustic velocity and density of mudstone in the normally compacted section in the structural extrusion area before and after the structural extrusion effect, specifically including:

[0086] Step 3.1: Use the data of Well S2 to establish an average effective stress model for normal compaction under the action of only vertical stress without structural extrusion in this well, as shown in the following formula:

[0087]

[0088] Among them, is the average effective stress for normal compaction under the action of only vertical stress without structural extrusion, σ v1is the vertical load stress under the action of no tectonic extrusion and only vertical stress, ν is the stress ratio coefficient, taking 0.43, ρ w is the density of formation water, taking 1.03, g is the acceleration of gravity, h is the burial depth, where σ v1 can be further expressed as:

[0089]

[0090] Among them, ρ(h) is the density function varying with depth, expressed as

[0091] ρ(h) = a·h b

[0092] Among them, a and b are the fitting coefficients obtained from the power function relationship between the logging density and the burial depth of Well S2. The values of a and b are 1.031 and 0.101 respectively. Substitute ρ(h) into σ v to obtain the relationship between the average effective stress of mudstone in the normally compacted section of Well S2 and the burial depth as:

[0093]

[0094] Step 3.2: Establish the average effective stress model of normal compaction under the action of tectonic extrusion in Well S1; as shown in the following formula:

[0095]

[0096] Among them, is the average effective stress of normal compaction under the action of tectonic extrusion, σ v2 is the vertical load stress under the action of tectonic extrusion, and its expression is shown in Step 3.1. Different from it, the x and y coefficients need to be obtained by fitting the power function relationship between the logging density and the burial depth under the action of tectonic extrusion in Well S1. The values of a and b are 2.173 and 0.019 respectively. σ T is the tectonic extrusion stress. Here, the tectonic extrusion stress σ T is a function of the burial depth in the shallow part. When the burial depth is greater than a certain depth, it is a constant value, and can be expressed as:

[0097]

[0098]

[0099] Among them, σ Tmax is the maximum tectonic stress, here taking 300, z is the burial depth, z m is the given depth, here taking 10000, c is a constant, here taking 0.0002.

[0100] Step 3.3: Establish a relationship model between the density porosity and density of mudstone in the normally compacted section of Well S1 in the tectonic extrusion area and Well S2 in the non-tectonic extrusion area, as shown in the following formula:

[0101]

[0102] where Φ density is the density porosity, ρ ma is the density of the matrix, both taken as 2.71 for the two wells, ρ f is the density of formation water, both taken as 1.03 for the two wells, ρ b is the density obtained from logging.

[0103] The established relationship model between the density porosity and density of mudstone in the normally compacted section of Well S1 and Well S2 is as shown in the following formula:

[0104]

[0105] When calculating the density porosity of the two wells, ρ b takes their respective actual logging values.

[0106] Step 3.4: Establish a relationship model between the acoustic porosity and acoustic travel time of mudstone in the normally compacted section of Well S1 in the tectonic extrusion area and Well S2 in the non-tectonic extrusion area, as shown in the following formula:

[0107]

[0108] where Φ sonic is the acoustic porosity, Δt f is the acoustic travel time of formation water, taken as 620, Δt ma is the acoustic travel time of the matrix, taken as 176.5, Δt is the acoustic travel time obtained from logging, C p is the proportionality coefficient between the acoustic porosity and the density porosity.

[0109] The established relationship model between the acoustic porosity and acoustic travel time of mudstone in the normally compacted section of Well S1 in the tectonic extrusion area is as shown in the following formula:

[0110] Φ sonic = 0.00169·Δt - 0.2985

[0111] The established relationship model between the acoustic porosity and acoustic travel time of mudstone in the normally compacted section of Well S2 in the non-tectonic extrusion area is as shown in the following formula:

[0112] Φ sonic = 0.00146·Δt - 0.2587

[0113] Step 3.5: Using the average effective stress of the shale in the normally compacted section of Well S1 obtained in Step 3.2 and the acoustic porosity of the shale in the normally compacted section of Well S1 obtained in Step 3.4, establish a relationship model between the acoustic porosity and its average effective stress of the shale in the normally compacted section of Well S1 in the tectonic compression area, as shown in the following formula:

[0114]

[0115] where, Φ sonic is the acoustic porosity, is the average effective stress, and d and f are constants obtained by fitting the average effective stress and acoustic porosity of the normally compacted section of Well S1 obtained in Steps 3.2 and 3.4 respectively, and their magnitudes are 0.612 and 0.0639 ( Figure 4 ).

[0116] Step 3.6: Substitute the average effective stress of the normally compacted section of Well S1 under the action of only vertical stress without tectonic compression obtained in Step 3.1 into the formula in Step 3.5 to obtain the acoustic porosity of the shale in the normally compacted section of Well S1 under the action of only vertical stress without tectonic compression. Further combine it with the relationship model between density porosity and density in Step 3.3 and the relationship model between acoustic porosity and acoustic travel time in Step 3.4 to respectively obtain the acoustic travel time and density of the shale in the normally compacted section at different burial depths of Well S1 under the action of only vertical stress without tectonic compression. Using the reciprocal relationship between sound velocity and acoustic travel time, obtain the acoustic velocity of the shale in the normally compacted section of Well S1 under the action of only vertical stress without tectonic compression. Further establish an exponential relationship model between the acoustic velocity and density of the normally compacted section of Well S1 under the action of only vertical stress without tectonic compression, as shown in the following formula:

[0117]

[0118] where, V sonic is the acoustic velocity, ρ b is the density obtained by logging, and w and i are constants obtained by fitting the acoustic velocity and density of the normally compacted section of Well S1 under the action of only vertical stress without tectonic compression, and their values are 0.0896 and 1.361 ( Figure 5 ). The relationship model between the acoustic velocity and density of the normally compacted section of Well S1 under the action of tectonic compression is similar to the exponential relationship model between the acoustic velocity and density of the normally compacted section of this well under the action of only vertical stress without tectonic compression. After fitting, their w and i are 0.0534 and 1.715 respectively ( Figure 5 ). By comparing the changes in acoustic velocity and density of the shale in the normally compacted section at the same burial depth under the two conditions of only vertical stress without tectonic compression and tectonic compression, the evolution path of the shale in the normally compacted section of Well S1 from the starting point under the action of only vertical stress without tectonic compression to the end point after tectonic compression can be reconstructed (Figure 5 )。

[0119] Step 4: Reconstruct the evolution paths of the acoustic velocity and density of mudstone in the overpressure section of the tectonic compression area before and after the tectonic compression, specifically including:

[0120] Substitute the normal compaction density corresponding to the overpressure section under the S1 tectonic compression into the exponential relationship model between the acoustic velocity and density of the normal compaction section under the tectonic compression established in Step 3 to obtain the acoustic velocity of the normal compaction corresponding to the overpressure section under the S1 tectonic compression. Use the acoustic velocity and density of mudstone obtained from logging in the overpressure section under the S1 tectonic compression and the calculated acoustic velocity and density of the normal compaction section corresponding to this section to establish a linear relationship model between these two points, such as Figure 6 points W and R in. Obtain the intersection point of this linear relationship model and the exponential relationship model between the acoustic velocity and density of mudstone in the normal compaction section under only vertical stress without tectonic compression to obtain the acoustic velocity and density under only vertical stress without tectonic compression corresponding to the overpressure section under the tectonic compression; compare the acoustic velocity and density of mudstone in the overpressure section at the same burial depth under the two conditions of only vertical stress without tectonic compression and tectonic compression, so as to reconstruct the evolution paths of the acoustic velocity and density of mudstone in the overpressure section of the tectonic compression area before and after the tectonic compression, such as Figure 6 from point R to point U in.

[0121] Step 5: Quantitatively calculate the magnitude of the tectonic compression-induced overpressure increase in the overpressure section of Well S1 in the tectonic compression area, specifically including:

[0122] Step 5.1: Establish a quantitative model for the vertical effective stress in the normal compaction section under the tectonic compression of Well S1 in the tectonic compression area and under only vertical stress without tectonic compression, as shown in the following formula:

[0123] δ = σ v - P 静 = σ v - ρ 水 ·g·h

[0124] where δ is the vertical effective stress, σ v is the vertical load stress. In the case of tectonic compression, σ v is the same as the above σ v2 . In the case of only vertical stress without tectonic compression, σ v is the same as the above σ v1 . The calculation method can be found in Steps 3.1 and 3.2. P 静 is the formation hydrostatic pressure, ρ 水 is the density of formation water, taken as 1.03, g is the acceleration due to gravity, and h is the burial depth.

[0125] Step 5.2: Combine the vertical effective stress of the mudstone in the normal compaction section under only vertical stress without tectonic extrusion obtained in Step 5.1 with the density of the mudstone in the normal compaction section under only vertical stress without tectonic extrusion of this well determined by using Step 3, and establish a relationship model between the density and the vertical effective stress of the mudstone in the normal compaction section under only vertical stress without tectonic extrusion of Well S1 in the tectonic extrusion area, as shown in the following formula:

[0126]

[0127] where ρ b无 is the density of the mudstone under only vertical stress without tectonic extrusion, δ 无 is the vertical effective stress under only vertical stress without tectonic extrusion, and k and m are the fitting coefficients of the density and the vertical effective stress of the mudstone in the normal compaction section under only vertical stress without tectonic extrusion of Well S1, and their values are 1.850 and 0.0733 respectively( Figure 7 ).

[0128] Step 5.3: Combine the relationship model between the density and the vertical effective stress of the mudstone in the normal compaction section under only vertical stress without tectonic extrusion of Well S1 established in Step 5.2 with the density under only vertical stress without tectonic extrusion corresponding to the overpressure section of Well S1 obtained by using Step 4 to obtain the vertical effective stress under only vertical stress without tectonic extrusion corresponding to the overpressure section of this well( Figure 7 Z point in), compare the vertical stress differences of this overpressure section under the two conditions of tectonic extrusion and only vertical stress without tectonic extrusion, and obtain the vertical effective stress of this overpressure section of Well S1 after tectonic extrusion compaction.

[0129] Step 5.4: Use the density and vertical effective stress data of the mudstone in the normal compaction section under tectonic extrusion of Well S1 to establish a relationship model between the two, as shown in the following formula:

[0130]

[0131] where ρ b有 is the density of the mudstone under tectonic extrusion, δ 有 is the vertical effective stress under tectonic extrusion, and n and q are the fitting coefficients of the density and the vertical effective stress of the mudstone in the normal compaction section under tectonic extrusion of Well S1, and their values are 2.271 and 0.0354 respectively( Figure 7 ). Substitute the density of the mudstone adjacent to the measured overpressure section( Figure 7 T1 point in) of Well S1 in the tectonic extrusion area into this formula to obtain the vertical effective stress corresponding to this overpressure section after experiencing tectonic extrusion pressurization, as Figure 7 Y point in; when the vertical effective stress corresponding to this overpressure section after experiencing tectonic extrusion pressurization obtained by this calculation is greater than or equal to the vertical effective stress obtained from the measured pressure of this overpressure section(Figure 7 At the T1 point in the middle), the vertical effective stress after tectonic extrusion compaction of the same overpressure section obtained according to step 5.3 ( Figure 7 At the M point in) is subtracted from the vertical effective stress after tectonic extrusion pressure increase of the same layer section obtained in this step ( Figure 7 At the Y point in) to obtain the magnitude of tectonic extrusion pressure increase of this overpressure section; when the vertical effective stress corresponding to this overpressure section after experiencing tectonic extrusion pressure increase obtained through this calculation ( Figure 7 At the Y point in) is less than the vertical effective stress obtained from the measured pressure of this overpressure section ( Figure 7 At the T2 point in), the vertical effective stress after tectonic extrusion compaction of this overpressure section is subtracted from the vertical effective stress obtained from the measured pressure of this overpressure section to obtain the magnitude of tectonic extrusion pressure increase of this overpressure section.

[0132] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the technical principle of the present invention, several improvements and deformations can also be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A method for evaluating construction extrusion pressurization based on the idea of dynamic evolution, characterized in that It includes the following steps: Step 1: Arrange the pressure data and logging data. The pressure data includes the measured formation pressure coefficient, the formation pressure coefficient measured while drilling, and the mud density. The logging data includes the acoustic time difference, density, and resistivity of mudstone at different burial depths; Step 2: Use the data of the acoustic time difference, density, resistivity of mudstone at different burial depths, the formation pressure coefficient measured while drilling, the mud density, and the variation relationship of the measured formation pressure coefficient with burial depth sorted in Step 1 to comprehensively judge the normally compacted section and the overpressure section; Step 3: Reconstruct the evolution paths of the acoustic velocity and density of mudstone in the normally compacted section of the tectonic compression area before and after the tectonic compression, and determine the acoustic velocity and density of mudstone in the normally compacted section of the tectonic compression area under the action of only vertical stress without tectonic compression; Step 4: Reconstruct the evolution paths of the acoustic velocity and density of mudstone in the overpressure section of the tectonic compression area before and after the tectonic compression, and determine the acoustic velocity and density corresponding to the overpressure section of the tectonic compression area under the action of only vertical stress without tectonic compression; Step 5: Use the results of Step 3 and Step 4 to quantitatively calculate the magnitude of tectonic compression and pressure increase in the overpressure interval, which specifically includes the following steps: Step 5.1: Establish a quantitative model of the vertical effective stress in the normally compacted section under the action of tectonic compression and under the action of only vertical stress without tectonic compression in the tectonic compression area, as shown in the following formula: Among them, is the vertical effective stress, is the vertical load stress. In the case of tectonic extrusion, is the same as the above-mentioned . Under the action of only vertical stress without tectonic extrusion, is the same as the above-mentioned . is the formation hydrostatic pressure, is the formation water density, is the acceleration of gravity, is the burial depth; Step 5.2: Combine the vertical effective stress of mudstone in the normally compacted section of the actual well under the action of only vertical stress without tectonic compression obtained in Step 5.1 with the density of mudstone in the normally compacted section of the actual well under the action of only vertical stress without tectonic compression determined in Step 3 to establish a relationship model between the density and vertical effective stress of mudstone in the normally compacted section of the tectonic compression area under the action of only vertical stress without tectonic compression, as shown in the following formula: Among them, is the density of mudstone under the action of only vertical stress without tectonic extrusion, is the vertical effective stress under the action of only vertical stress without tectonic extrusion, and k and m are the fitting coefficients of the density and vertical effective stress of mudstone in the normal compaction section under the action of only vertical stress without tectonic extrusion in the actual well; Step 5.3: Combine the relationship model between the density and vertical effective stress of mudstone in the normally compacted section of the actual well in the tectonic compression area under the action of only vertical stress without tectonic compression established in Step 5.2 with the density corresponding to the overpressure section of the actual well under the action of only vertical stress without tectonic compression obtained in Step 4 to obtain the vertical effective stress corresponding to the overpressure section of the actual well under the action of only vertical stress without tectonic compression, compare the vertical stress differences in the overpressure section under the two cases of tectonic compression and only vertical stress without tectonic compression, and obtain the vertical effective stress of the overpressure section after tectonic compression compaction; Step 5.4: Use the density and vertical effective stress data of mudstone in the normally compacted section under tectonic compression of the actual well to establish a relationship model between the two, as shown in the following formula: Among them, is the density of mudstone under tectonic compression, is the vertical effective stress under tectonic compression, and n and q are the fitting coefficients of the density and vertical effective stress of mudstone in the normal compaction section under the actual well tectonic compression; Substitute the density of the mudstone adjacent to the actual well overpressure section in the tectonic extrusion area into this formula to obtain the vertical effective stress corresponding to this overpressure section after experiencing tectonic extrusion pressurization; when the vertical effective stress corresponding to this overpressure section after experiencing tectonic extrusion pressurization calculated is greater than or equal to the vertical effective stress obtained from the measured pressure of this overpressure section, subtract the vertical effective stress of the same overpressure section after tectonic extrusion compaction obtained according to step 5.3 from the vertical effective stress of the same layer section after experiencing tectonic extrusion pressurization obtained in this step, and the tectonic extrusion pressurization of this overpressure section can be obtained; when the vertical effective stress corresponding to this overpressure section after experiencing tectonic extrusion pressurization calculated is less than the vertical effective stress obtained from the measured pressure of this overpressure section, subtract the vertical effective stress of this overpressure section after tectonic extrusion compaction from the vertical effective stress obtained from the measured pressure of this overpressure section, and the tectonic extrusion pressurization of this overpressure section can be obtained.

2. The construction extrusion pressurization evaluation method based on the idea of dynamic evolution according to claim 1, characterized in that, The specific content of step 3 is as follows: Using the normal compaction section determined in step 2, select typical wells in the tectonic extrusion area and the non-tectonic extrusion area, and respectively establish a quantitative model of the average effective stress of the normal compaction section under two conditions: the tectonic extrusion effect in the tectonic extrusion area and only the vertical stress effect without tectonic extrusion, using well logging density data, to obtain the average effective stress of the normal compaction section under the two conditions; Using well logging density data, respectively establish a relationship model between the density porosity and density of the mudstone in the normal compaction section in the tectonic extrusion area and the non-tectonic extrusion area, to obtain the density porosity of the mudstone in the normal compaction section; Using well logging acoustic travel time data, respectively establish a relationship model between the acoustic porosity and acoustic travel time of the mudstone in the normal compaction section in the tectonic extrusion area and the non-tectonic extrusion area, to obtain the acoustic porosity of the mudstone in the normal compaction section; Establish a relationship model between the acoustic porosity and the average effective stress of the mudstone in the normal compaction section in the tectonic extrusion area, combine it with the average effective stress of the normal compaction section under the condition of only vertical stress without tectonic extrusion in the tectonic extrusion area, calculate the acoustic porosity of the mudstone in the normal compaction section under the condition of only vertical stress without tectonic extrusion, and further combine it with the relationship model between the acoustic porosity and acoustic travel time and the relationship model between density porosity and density of the mudstone in the normal compaction section in the non-tectonic extrusion area, respectively obtain the acoustic travel time and the density of the mudstone in the normal compaction section under the condition of only vertical stress without tectonic extrusion in the tectonic extrusion area, use the reciprocal relationship between the sound velocity and the acoustic travel time to obtain the acoustic velocity of the mudstone in the normal compaction section under the condition of only vertical stress without tectonic extrusion in the tectonic extrusion area, and establish a relationship model between the acoustic velocity and density of the normal compaction section under the condition of only vertical stress without tectonic extrusion in the tectonic extrusion area; Use the well logging acoustic travel time in the tectonic extrusion area to obtain the acoustic velocity, and establish a relationship model between the acoustic velocity and density of the normal compaction section under the tectonic extrusion effect in the tectonic extrusion area; combine this relationship model with the relationship model between the acoustic velocity and density of the normal compaction section under the condition of only vertical stress without tectonic extrusion in the tectonic extrusion area, so as to reconstruct the evolution path of the acoustic velocity and density of the mudstone in the normal compaction section in the tectonic extrusion area before and after the tectonic extrusion effect, and obtain the acoustic velocity and density of the mudstone in the normal compaction section under the condition of only vertical stress without tectonic extrusion in the tectonic extrusion area.

3. The construction extrusion supercharging evaluation method based on the dynamic evolution idea according to claim 2, wherein The specific content of step 3 includes the following steps: Step 3.1: Establish an average effective stress model for the normal compaction section under the action of non-structural extrusion with only vertical stress, as shown in the following formula: Among them, is the average effective stress of the normal compaction section under the action of only vertical stress without tectonic extrusion, is the vertical load stress under the action of only vertical stress without tectonic extrusion, ν is the stress ratio coefficient, is the formation water density, g is the acceleration of gravity, h is the burial depth; Vertical load stress under only vertical stress without tectonic extrusion σ v1 It is further expressed as: Among them, is a density function that varies with depth, expressed as: where a and b are fitting coefficients obtained from the power function relationship between the logging density and burial depth of wells in the unstructured extrusion zone. Substitute into . That is, the average effective stress model of the normal compaction section under the action of only vertical stress without structural extrusion is further expressed as: Step 3.2: Establish an average effective stress model for normal compaction under the action of structural extrusion, as shown in the following formula: Among them, is the average effective stress of normal compaction under tectonic extrusion, is the vertical load stress under tectonic extrusion. Its expression is shown in step 3.

1. Different from it, the x and y coefficients need to be obtained by fitting the power function relationship between the logging density and burial depth under the tectonic extrusion in the tectonic extrusion area. is the tectonic extrusion stress; The structural extrusion stress is a function of the burial depth in the shallow part, and is a constant value when the burial depth is greater than a given depth, expressed as: Among them, is the maximum tectonic stress, z is the burial depth, is the given depth, and c is a constant; Step 3.3: Establish a relationship model between the density porosity and density of mudstone in the normal compaction section in the structural extrusion area and the non-structural extrusion area, as shown in the following formula: Among them, is the density porosity, ρ ma is the density of the matrix, ρ f is the density of the formation water, ρ b is the density obtained from logging; Step 3.4: Establish a relationship model between the acoustic porosity and acoustic travel time of mudstone in the normal compaction section in the structural extrusion area and the non-structural extrusion area, as shown in the following formula: wherein, Φ sonic is the acoustic porosity, Δ t f is the acoustic travel time of formation water, Δ t ma is the acoustic travel time of matrix, Δ t is the acoustic travel time obtained from logging, C p is the proportionality coefficient between acoustic porosity and density porosity; Step 3.5: Using the average effective stress obtained in Step 3.2 and the acoustic porosity obtained in Step 3.4, establish a relationship model between the acoustic porosity and its average effective stress of mudstone in the normal compaction section in the structural extrusion area, as shown in the following formula: Among them, Φ sonic is the acoustic porosity, is the average effective stress, and d and f are constants obtained by fitting the average effective stress and acoustic porosity of the actual well normal compaction section obtained in Steps 3.2 and 3.4 respectively; Step 3.6: Substitute the average effective stress of the normal compaction section under the action of non-structural extrusion with only vertical stress in the actual well obtained in Step 3.1 into the formula in Step 3.5 to obtain the acoustic porosity of mudstone in the normal compaction section under the action of non-structural extrusion with only vertical stress. Further combine it with the relationship model between density porosity and density in Step 3.3 and the relationship model between acoustic porosity and acoustic travel time in Step 3.4 to respectively obtain the acoustic travel time and density of mudstone in the normal compaction section at different burial depths under the action of non-structural extrusion with only vertical stress in the structural extrusion area. Using the reciprocal relationship between sound velocity and acoustic travel time, obtain the acoustic velocity of mudstone in the normal compaction section at different burial depths under the action of non-structural extrusion with only vertical stress in the structural extrusion area. Further establish an exponential relationship model between the acoustic velocity and density of the normal compaction section under the action of non-structural extrusion with only vertical stress in the structural extrusion area, as shown in the following formula: Among them, V sonic is the acoustic wave velocity, ρ b is the density obtained from well logging. w and i are constants obtained by fitting the acoustic wave velocity and density of the normal compaction section under the action of only vertical stress without tectonic extrusion in the actual well. The relationship model between the acoustic wave velocity and density of the normal compaction section under the action of tectonic extrusion in the tectonic extrusion area is similar to the exponential relationship model between the acoustic wave velocity and density of the normal compaction section under the action of only vertical stress without tectonic extrusion in the tectonic extrusion area, and only the w and i constants are replaced by the constants obtained by fitting the acoustic wave velocity and density from the well logging data of the actual well in the tectonic extrusion area; Compare the acoustic velocity and density of mudstone in the normal compaction section at the same burial depth under the two conditions of non-structural extrusion with only vertical stress and structural extrusion, so as to reconstruct the evolution path of mudstone in the normal compaction section in the structural extrusion area from the starting point to the end point under the action of structural extrusion.

4. A method for evaluating construction extrusion pressurization based on the idea of dynamic evolution according to claim 3, characterized in that The specific content of Step 4 is as follows: Substitute the normal compaction density corresponding to the overpressure section under the action of structural extrusion into the exponential relationship model between the acoustic velocity and density of the normal compaction section under the action of structural extrusion established in Step 3.6 to obtain the normal compaction acoustic velocity corresponding to the overpressure section under the action of structural extrusion; Using the acoustic velocity and density of mudstone obtained by logging in the overpressure section under the action of structural extrusion and the acoustic velocity and density of the corresponding normal compaction section, establish a linear relationship model between these two points, and obtain the intersection point of the linear relationship model of this overpressure section and the exponential relationship model between the acoustic velocity and density of mudstone in the normal compaction section under the action of non-structural extrusion with only vertical stress to obtain the acoustic velocity and density under the action of non-structural extrusion with only vertical stress corresponding to the overpressure section under the action of structural extrusion; Compare the acoustic velocity and density of mudstone in the overpressure section at the same burial depth under the two conditions of non-structural extrusion with only vertical stress and structural extrusion, so as to reconstruct the evolution path of the acoustic velocity and density of mudstone in the overpressure section in the structural extrusion area before and after the action of structural extrusion, and obtain the acoustic velocity and density under the action of non-structural extrusion with only vertical stress corresponding to the overpressure section in the structural extrusion area.

5. A method for evaluating construction extrusion pressurization based on the idea of dynamic evolution according to claim 3, characterized in that The specific content of Step 5 is as follows: Using well logging density data, a quantitative model of vertical effective stress in the normal compaction section under tectonic extrusion and under vertical stress only without tectonic extrusion in the tectonic extrusion area is established. The vertical effective stress under vertical stress only without tectonic extrusion in the tectonic extrusion area is obtained. Combining it with the shale density in the normal compaction section under vertical stress only without tectonic extrusion determined in Step 3, a relationship model between the shale density and the vertical effective stress in the normal compaction section under vertical stress only without tectonic extrusion in the tectonic extrusion area is established. Combining it with the density under vertical stress only without tectonic extrusion corresponding to the overpressure section in the tectonic extrusion area obtained in Step 4, the vertical effective stress under vertical stress only without tectonic extrusion corresponding to the overpressure section in the tectonic extrusion area is obtained. By comparing the vertical stress differences of this overpressure section under two conditions of tectonic extrusion and vertical stress only without tectonic extrusion, the vertical effective stress after tectonic extrusion compaction of this overpressure section is obtained; Using the density and vertical effective stress data of shale in the normal compaction section under tectonic extrusion, a relationship model between the two is established. Combining it with the density of the shale adjacent to the overpressure section under tectonic extrusion, the vertical effective stress corresponding to this overpressure section after experiencing tectonic extrusion pressure increase is obtained; Subtracting the vertical effective stress after tectonic extrusion compaction of the same overpressure section from the vertical effective stress corresponding to it after experiencing tectonic extrusion pressure increase, the tectonic extrusion pressure increase of this overpressure section is obtained.

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