Method, device, equipment and storage medium for determining formation pressure

Abstract

This application provides a method, apparatus, device, and storage medium for determining formation pressure, relating to the field of petroleum exploration technology. Based on the prediction of formation pressure based on the undercompaction mechanism, the method further considers the impact of different structural elements on formation pressure, thereby achieving structural correction of formation pressure and improving the accuracy of formation pressure prediction in complex structural areas. The method for determining formation pressure includes: obtaining a first formation pressure in a target area using a pressure prediction method based on the undercompaction theory; and correcting the first formation pressure based on the impact of the structural elements in the target area on the formation pressure.

Description

Technical Field

[0001] The present application relates to the field of oil exploration technology, and in particular to a method, device, equipment and storage medium for determining formation pressure. Background Art

[0002] Currently, shale gas exploration and development in my country is still in its infancy, characterized by high risks and costs. Shale gas development encounters increasingly complex formation pressure systems, placing increasing demands on the accuracy of formation pressure predictions. Conventional pre-drilling formation pressure prediction methods are mostly based on velocity spectra or seismic layer velocity data. Their prediction mechanism is based on the constant compaction trend of mudstones, resulting in low resolution. These methods are designed to address the causes of undercompaction, and therefore lack sufficient accuracy for formation pressure prediction in complex tectonic areas. Summary of the Invention

[0003] In response to the above problems, the present application provides a method, device, equipment and storage medium for determining formation pressure. On the basis of predicting formation pressure based on the undercompaction mechanism, it further considers the influence of different structural elements on formation pressure, thereby realizing structural correction of formation pressure and improving the accuracy of formation pressure prediction in complex structural areas.

[0004] An embodiment of the present application provides a method for determining formation pressure, comprising:

[0005] Using a pressure prediction method based on undercompaction genesis theory, the first formation pressure in the target area is obtained;

[0006] The first formation pressure is corrected according to the influence of the structural elements of the target area on the formation pressure.

[0007] In some embodiments of the present application, the structural element includes at least one of a compression structure, a fault, and a burial depth.

[0008] In some embodiments of the present application, the correcting of the first formation pressure according to the influence of the structural elements of the target area on the formation pressure includes at least one of the following:

[0009] According to the compression structure existing in the target area, the first formation pressure is corrected by introducing relative compression structure stress and structure pressure factor;

[0010] The target area is divided into a plurality of different pressure systems according to structural units. For each pressure system, the first formation pressure is corrected according to the distance from the fault and the influence of the burial depth on the formation pressure.

[0011] In some embodiments of the present application, the correcting the first formation pressure according to the influence of structural elements of the target area on the formation pressure includes:

[0012] According to the compression structure existing in the target area, by introducing relative compression structure stress and structure pressure factor, calculating the first impact of the compression structure on the formation pressure;

[0013] Dividing the target area into a plurality of different pressure systems according to structural units, and calculating, for each pressure system, a second influence amount and a third influence amount of the distance and burial depth on the formation pressure based on the influence of the distance and burial depth on the formation pressure;

[0014] Based on the first influencing amount, the second influencing amount and the third influencing amount, the formation pressure of the target area after correction considering the influence of structural elements is determined in a weighted summation manner.

[0015] In some embodiments of the present application, the first influencing quantity is: ΔP Q =α*σ T +exp(b-φ) where α is the contribution rate of compression structure to formation pressure, σ T is the compressive tectonic stress, φ is the porosity, and b is a constant.

[0016] In some embodiments, the contribution rate α of the compression structure to the formation pressure is generated based on curvature attributes.

[0017] In some embodiments, the extrusion stress is obtained by the following formula:

[0018]

[0019] Among them, σ T is the compression tectonic stress; σ Tmax is the maximum extrusion stress; H is the depth; H0 is the critical depth, and α is the coefficient.

[0020] In some embodiments, the effect of the distance from a fault on the formation pressure can be expressed as:

[0021]

[0022] Where ΔP D1 are the impact of a certain fault on the formation pressure, and dis_DC1 is the distance from the fault;

[0023] The second impact amount is the sum of the impacts of multiple faults in the target area on the formation pressure.

[0024] In some embodiments, the third influence amount is:

[0025] ΔP T =β*time+ε,

[0026] Where ΔP T is the third influence quantity caused by the influence of burial depth on formation pressure, time is time, and β and ε are constants.

[0027] In some embodiments, the formation pressure of the target area after correction considering the influence of structural elements is:

[0028] P M =P+a q *ΔP Q +a d *ΔP D +a t *ΔP T

[0029] P M is the corrected formation pressure, P is the first formation pressure without considering the structural influence, ΔP Q is the first influence of the compression structure on the formation pressure, ΔP D is the second influence of the fault on the formation pressure, ΔP T is the third influence of burial depth on formation pressure, a q 、a d 、a t are correction coefficients for the first influence amount, the second influence amount, and the third influence amount, respectively.

[0030] The present application also provides a device for determining formation pressure, comprising:

[0031] an acquisition module, configured to acquire a first formation pressure in a target area, wherein the first formation pressure is obtained by using a pressure prediction method based on an undercompaction genesis theory;

[0032] The correction module is used to correct the first formation pressure according to the influence of the structural elements of the target area on the formation pressure.

[0033] In some embodiments, the correction module includes:

[0034] A first correction submodule is configured to calculate a first impact of the compression structure on the formation pressure by introducing relative compression structure stress and a structural pressure factor according to the compression structure existing in the target area;

[0035] The second correction submodule and the third correction submodule divide the target area into a plurality of different pressure systems according to the structural units, and respectively calculate, for each pressure system, a second influence amount and a third influence amount of the distance and the burial depth on the formation pressure according to the influence of the distance from the fault and the burial depth on the formation pressure;

[0036] The formation pressure determination submodule is used to determine the formation pressure of the target area after correction considering the influence of structural elements based on the first influence amount, the second influence amount and the third influence amount in a weighted summation manner.

[0037] An embodiment of the present application provides a device for determining formation pressure, including a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, any one of the above-mentioned methods for determining formation pressure is executed.

[0038] An embodiment of the present application provides a storage medium, which stores a computer program that can be executed by one or more processors and can be used to implement any of the above-mentioned methods for determining formation pressure.

[0039] The present application provides a method, device, equipment and storage medium for determining formation pressure. To address the problem that conventional pressure prediction methods based on undercompaction genesis theory are difficult to adapt to the prediction of formation pressure in complex structural areas, the present application further considers the influence of different structural elements on formation pressure on the basis of predicting formation pressure based on the undercompaction genesis mechanism, thereby achieving structural correction of formation pressure and improving the accuracy of formation pressure prediction in complex structural areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Hereinafter, the present application will be described in more detail based on embodiments with reference to the accompanying drawings.

[0041] Figure 1 A schematic diagram of a flow chart for implementing a method for determining formation pressure provided in an embodiment of the present application;

[0042] Figure 2 A schematic diagram of a flow chart for implementing another method for determining formation pressure provided in an embodiment of the present application;

[0043] Figure 3 A schematic diagram of a flow chart for implementing another method for determining formation pressure provided in an embodiment of the present application;

[0044] Figure 4 The formation pressure prediction result before correction provided in this embodiment (i.e., the result calculated based on the undercompaction genesis prediction method);

[0045] Figure 5 A schematic diagram of a complex structural shale gas block in the Sichuan Basin of China provided in an embodiment of the present application;

[0046] Figure 6 is the formation pressure prediction result obtained after correction according to the formation pressure correction method of this embodiment;

[0047] Figure 7A schematic diagram of the implementation flow of another method for determining formation pressure provided in an embodiment of the present application.

[0048] Figure 8 A schematic diagram of the implementation flow of another method for determining formation pressure provided in an embodiment of the present application.

[0049] Figure 9 A schematic diagram of the implementation flow of another method for determining formation pressure provided in an embodiment of the present application.

[0050] Figure 10 A schematic structural diagram of a device for determining formation pressure provided in an embodiment of the present application;

[0051] Figure 11 A schematic structural diagram of another device for determining formation pressure provided in an embodiment of the present application;

[0052] Figure 12 Schematic diagram of the composition structure of the device for determining formation pressure provided in an embodiment of the present application.

[0053] In the drawings, like components are given like reference numerals, and the drawings are not drawn to scale. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limiting this application. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0055] In the following description, references to “some embodiments” describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0056] If similar descriptions of "first\second\third" appear in the application documents, the following explanation will be added. In the following description, the terms "first\second\third" are only used to distinguish similar objects and do not represent a specific order for the objects. It can be understood that "first\second\third" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0058] Abnormal formation pressure is common worldwide, and its causes are diverse, potentially physical, chemical, or a combination of both. Abnormal pressure includes abnormally low pressure (negative pressure) and abnormally high pressure (overpressure). Globally, the types and distribution of abnormally high pressure mechanisms are greater than those of abnormally low pressure, and the hazards of abnormally high pressure to drilling are also greater than those of abnormally low pressure. Therefore, research on high pressure far exceeds that on low pressure.

[0059] Tectonic action is one of the important factors that form abnormally high pressure in basins with strong activity. Regional uplift, folding, faulting, landslide, collapse, and penetration (salt rock or mud shale) can all cause abnormally high pressure systems. Regional uplift and uplift are important factors that cause abnormally high pressure. The reason is simple. When tectonic uplift causes the strata to be weathered and eroded, the pressure of the overlying strata decreases. This process is also an unloading process, and the stress-strain relationship conforms to the unloading curve. If the tectonic uplift does not destroy the closed environment of the strata before the uplift, the vertical effective stress decreases, while the pore pressure remains approximately unchanged (maintaining the pressure at the depth before the uplift), or the pressure drop rate caused by the temperature drop per unit depth is lower than the hydrostatic pressure gradient, the result is abnormally high pressure that is inconsistent with the normal pressure at the shallower depth after the uplift, thus forming an abnormally high pressure system.

[0060] Existing pre-drilling formation pressure prediction requires the use of seismic data. Conventional seismic-based formation pressure prediction methods rely on velocity spectra obtained during seismic data processing and employ empirical formulas (the Fillippone method) to predict pre-drilling formation pressure. These methods suffer from the following problems: ① The theoretical basis for seismic pressure prediction is incomplete. These methods are based on the concept of compaction and are not applicable to overpressures caused by non-compaction factors, particularly those from other sources. ② Prediction methods are limited and multi-solution, with all methods being based on assumptions and empirical evidence. Furthermore, there are multiple causes for seismic wave velocity decreases (or reversals), making it difficult to eliminate factors other than pressure. ③ The accuracy of seismic velocity estimates and seismic resolution are limited.

[0061] To address the problems existing in the related art, embodiments of the present application provide a method for determining formation pressure. The method is applied to a device for determining formation pressure, which may be an electronic device such as a computer or a mobile terminal. The functions implemented by the method for determining formation pressure provided in embodiments of the present application can be implemented by a processor of the electronic device invoking program code, wherein the program code may be stored in a computer storage medium.

[0062] Example 1

[0063] The present application provides a method for determining formation pressure. Figure 1A schematic diagram of a method for determining formation pressure according to an embodiment of the present application is provided. Figure 1 Shown, including:

[0064] Step S101, using a pressure prediction method based on undercompaction genesis theory to obtain a first formation pressure in a target area;

[0065] In embodiments of the present application, the first formation pressure of the target area can be pre-stored in a server, and the first formation pressure of the target area can be obtained by communicating with the server. In some embodiments, the first formation pressure can also be directly obtained by another formation pressure determination device. The other formation pressure determination device uses a pressure prediction method based on undercompaction genesis theory and can be determined based on a velocity spectrum or seismic layer velocity data. The other formation pressure determination device can also use other prediction methods that do not consider the impact of different structural elements on the formation pressure to obtain the formation pressure.

[0066] Step S102: Correcting the first formation pressure according to the influence of the structural elements of the target area on the formation pressure.

[0067] Geological structure refers to the shape left behind by deformation or displacement of rock layers or rock masses under the influence of internal and external stresses. It is most prominent in areas with layered rocks, but also occurs in areas with igneous and metamorphic rocks. Basic types of geological structure include horizontal, inclined, fold, and fault structures. Structural elements refer to the basic components of geological structures, such as folds, faults, joints, foliation, cleavage, and lineation.

[0068] In the embodiments of the present application, based on the prediction of formation pressure based on the undercompaction mechanism, the formation pressure is corrected by further considering the impact of different structural elements in the target area on the formation pressure. For complex structural areas, the pressure prediction method in the prior art (which generally does not consider the impact of different structural elements in the target area on the formation pressure) is first used to obtain a first formation pressure in the target area; then, the structural elements in the target area are examined, and the impact of these structural elements on the formation pressure is considered, and the first formation pressure is appropriately corrected. Since the corrected formation pressure takes into account the impact of the structural elements in the target area on the formation pressure, the formation pressure prediction accuracy for complex structural areas is higher.

[0069] Different structural elements have different effects on the formation pressure prediction, and the first formation pressure can be corrected according to the specific structural elements existing in the target area.

[0070] In some embodiments of the present application, the structural element includes at least one of a compression structure, a fault, and a burial depth.

[0071] In some embodiments of the present application, the structural elements include compression structures, faults, and burial depths. Step S102 : correcting the first formation pressure according to the effects of the compression structures, faults, and burial depths of the target area on the formation pressure.

[0072] Example 2

[0073] The present application provides a method for determining formation pressure. Figure 2 This is a schematic diagram of the implementation flow of another method for determining formation pressure provided in an embodiment of the present application. Figure 2 As shown, the method includes:

[0074] Step S101, using a pressure prediction method based on undercompaction genesis theory to obtain a first formation pressure in a target area;

[0075] Step S102: Correcting the first formation pressure according to the influence of the structural elements of the target area on the formation pressure.

[0076] In the present embodiment, step S102 is implemented through three key steps: 1) introducing relative compressive tectonic stress and tectonic pressure factors to perform tectonic correction of formation pressure; 2) dividing the study area into n different pressure systems based on tectonic units, and performing formation pressure correction considering the effects of distance from faults and burial depth on formation pressure; 3) finally, comprehensively considering the effects of relative compressive tectonic stress, distance from faults, and burial depth to achieve tectonic correction of formation pressure and improve the accuracy of formation pressure prediction in complex tectonic areas. These three key factors will be explained in the next embodiment in conjunction with specific examples.

[0077] Example 3

[0078] The present application provides a method for determining formation pressure. Figure 3 This is a schematic diagram of the implementation flow of another method for determining formation pressure provided in an embodiment of the present application. Figure 3 As shown, the method includes:

[0079] Step S101, using a pressure prediction method based on undercompaction genesis theory to obtain a first formation pressure in a target area;

[0080] Step S102: Correcting the first formation pressure according to the influence of the structural elements of the target area on the formation pressure.

[0081] In the embodiment of the present application, the correction step in step S102 includes:

[0082] Step S1021: Calculate a first impact of the compression structure on the formation pressure by introducing relative compression structure stress and a structural pressure factor based on the compression structure existing in the target area;

[0083] This step introduces relative compression tectonic stress and tectonic pressure factors to perform tectonic correction of formation pressure. The overpressure mechanism of tectonic origin can be explained by the unit cube model. If the compression is caused by the horizontal compression stress of the structure (such as folding), the direction of the maximum principal stress is horizontal and perpendicular to the direction of the minimum principal stress. For general sedimentary compaction, the vertical upward pressure of the overburden can be decomposed into the effective stress borne by the rock skeleton and the fluid pressure borne by the fluid. If the fluid partially bears the force that should be borne by the rock skeleton, the sediment will be undercompacted and the pressure therein will be overpressure. After the compression tectonic action occurs, the tectonic stress will cause lateral compaction of the rock, compressing the rock skeleton and increasing the fluid pressure. The size of the fluid pressure increment depends on the degree of closure and openness of the hydrodynamic system. Therefore, the relative compression tectonic stress formation pressure correction amount (the first influencing amount) ΔP Q It can be expressed as:

[0084] ΔP Q =α*σ T +exp(b-φ)

[0085] Where α is the contribution rate of compression structure to formation pressure, σ T is the compressive tectonic stress, φ is the porosity, and b is a constant.

[0086] α is often replaced by curvature. This is because curvature attributes describe geometric variations in geological bodies and are sensitive to bending, folding, cracking, and faulting in rock formations. Larger absolute values ​​of curvature attributes indicate greater formation curvature and compressive stress. Curvature attributes are preferably extracted from structural interpretation horizons, as they are easier to obtain and offer higher accuracy.

[0087] The magnitude of the ground stress in the compressional tectonic area is not constant, but changes with the depth of the stratum. A large number of drilling practices and studies have shown that in areas with severe compression, the magnitude of the ground stress change in the shallow layer is greater than that in the deep stratum. The law of the change of compressional tectonic stress with depth can be expressed as:

[0088]

[0089] Where, σ T is the compression tectonic stress, unit: MPa; σ Tmax is the maximum tectonic stress, unit: MPa; H is the depth, unit: m; H0 is the critical depth, unit: m; α is the coefficient, dimensionless.

[0090] Step S1022: Divide the target area into multiple different pressure systems according to structural units. For each pressure system, calculate the second and third influences of the distance and burial depth on the formation pressure based on the influence of the distance and burial depth on the formation pressure;

[0091] In some embodiments of the present invention, step S1022 divides the study area into n different pressure systems according to the structural units, taking into account the influence of the distance from the fault and the burial depth on the formation pressure.

[0092] A specific embodiment of a certain region, namely a complex structural shale gas block in the Sichuan Basin of China, is used as an example for explanation.

[0093] like Figure 5 As shown, the complex structural shale gas block of this specific embodiment has two main faults I and II running nearly north-south, which basically run through the entire study area.

[0094] Fractures Ⅰ and Ⅱ, i.e. Figure 5 The two black curves in the figure extend from the upper right area to the lower left area and the lower middle area. The study area is divided into three pressure systems based on these two faults.

[0095] Figure 5 The figure shows that two main faults divide the target area into three pressure systems.

[0096] In each pressure system, the distance and burial depth of each point on the plane from the fault are distributed and considered, and combined with the corresponding correction formula, the formation pressure correction in complex structural areas is achieved.

[0097] The effect of the distance from the fault on the formation pressure can be expressed as:

[0098]

[0099]

[0100] ΔP D =ΔP D1 +ΔP D2

[0101] Where ΔP D1 , ΔP D2 are the effects of a certain fault on the formation pressure, ΔP D is the combined effect of the distance from the two faults on formation pressure (the second influencing variable). dis_DC1 and dis_DC2 are the distances from the two faults, respectively. The effect of fault distance on formation pressure is expressed as a power function. The power function curve shows that the closer the distance to the fault, the more significant the impact, which is consistent with geological laws.

[0102] The effect of burial depth on formation pressure (the third influencing quantity) can be expressed as a function of time as follows:

[0103] ΔP T =β*time+ε

[0104] where ΔP T is the effect of burial depth on formation pressure, time is time, β and ε are constants.

[0105] Step S1023: Determine the formation pressure of the target area after correction considering the influence of structural elements based on a weighted summation method according to the first influence amount, the second influence amount, and the third influence amount.

[0106] This step comprehensively considers the influence of relative compression tectonic stress, distance from fault and burial depth, and sets correction coefficient a for different factors. q 、a d 、a t To express the influence of different factors, weighted calculation is performed to obtain the corrected formation pressure.

[0107] By calculating the formation pressure correction value of the above three tectonic factors (relative compression tectonic stress, distance from the fault, and burial depth), the influence of the tectonic factors in the study area on the formation pressure is calculated based on the weighted summation method, and high-precision seismic prediction of the formation pressure in the final target layer is achieved.

[0108] Specifically, in the following formula, P M is the corrected formation pressure, and P is the predicted formation pressure without considering the structural influence:

[0109] P M =P+a q *ΔP Q +a d *ΔP D +a t *ΔP T

[0110] ΔP Q is the first influence of the compression structure on the formation pressure, ΔP D is the second influence of the fault on the formation pressure, ΔP T is the third influence of burial depth on formation pressure, a q 、a d 、a t The corresponding correction factor, a q 、a d 、a t are the correction coefficients for different factors.

[0111] Figure 4This is the formation pressure prediction result before correction in this embodiment (i.e., the result calculated based on the undercompaction genesis prediction method).

[0112] Figure 5 A schematic diagram of a complex structural shale gas block in the Sichuan Basin of China provided in an embodiment of the present application.

[0113] Figure 6 This is the formation pressure prediction result obtained after correction according to the formation pressure correction method in this embodiment.

[0114] Specifically, if Figure 6 As shown in FIG, the first formation pressure at a certain point (point 1) is obtained using the pressure prediction method based on the undercompaction theory, and then corrected using the formation pressure correction method of this embodiment to obtain a predicted formation pressure of 1.56 MPa. The actual measured formation pressure at this point is 1.54 MPa.

[0115] At a certain point (point 2), the first formation pressure was obtained using a pressure prediction method based on the undercompaction theory. After correction using the formation pressure correction method described in this embodiment, the predicted formation pressure was 1.54 MPa. The actual measured formation pressure at this point was 1.62 MPa.

[0116] At a certain point (point 3), the first formation pressure is obtained by using the pressure prediction method based on the undercompaction theory, and then the formation pressure prediction result is 1.323Mpa after correction according to the formation pressure correction method of this embodiment. The actual formation pressure data at this point is 1.27Mpa

[0117] Comparing the formation pressure prediction result obtained after correction according to the formation pressure correction method of this embodiment with the error of the measured pressure data, it is found that the error between the two is less than 10%.

[0118] In response to the problem that conventional pressure prediction methods based on undercompaction genesis theory are difficult to adapt to the prediction of formation pressure in complex structural areas, the present invention proposes a method that, on the basis of predicting formation pressure based on the undercompaction genesis mechanism, further considers the influence of different structural elements such as relative compression structure, faults and burial depth on formation pressure, thereby realizing formation pressure structural correction and improving the accuracy of formation pressure prediction in complex structural areas.

[0119] Example 4

[0120] Figure 7 A schematic diagram of the implementation flow of another method for determining formation pressure provided in an embodiment of the present application.

[0121] Figure 8 A schematic diagram of the implementation flow of another method for determining formation pressure provided in an embodiment of the present application.

[0122] Figure 9 A schematic diagram of the implementation flow of another method for determining formation pressure provided in an embodiment of the present application.

[0123] An embodiment of the present application provides a method for determining formation pressure, the method comprising:

[0124] Step S101, using a pressure prediction method based on undercompaction genesis theory to obtain a first formation pressure in a target area;

[0125] Step S102: Correcting the first formation pressure according to the influence of the structural elements of the target area on the formation pressure.

[0126] In some embodiments of the present application, the correction step in step S102 includes at least one of the following:

[0127] According to the compression structure existing in the target area, the first formation pressure is corrected by introducing relative compression structure stress and structure pressure factor;

[0128] The target area is divided into a plurality of different pressure systems according to structural units. For each pressure system, the first formation pressure is corrected according to the distance from the fault and the influence of the burial depth on the formation pressure.

[0129] In other words, in some embodiments, Figure 7 As shown, another method for determining formation pressure includes:

[0130] Step S101, using a pressure prediction method based on undercompaction genesis theory to obtain a first formation pressure in a target area;

[0131] Step S102a: According to the compression structure existing in the target area, the first formation pressure is corrected by introducing relative compression structure stress and structure pressure factor.

[0132] A specific implementation process of step S102a can be found in the previous embodiment, the difference lies in the different coefficients, which will not be repeated here.

[0133] In some embodiments, as Figure 8 As shown, another method for determining formation pressure includes:

[0134] Step S101, using a pressure prediction method based on undercompaction genesis theory to obtain a first formation pressure in a target area;

[0135] Step S102b: Divide the target area into multiple different pressure systems according to structural units, and for each pressure system, correct the first formation pressure according to the distance from the fault and the influence of the burial depth on the formation pressure.

[0136] The specific implementation process of step S102b can be found in the previous embodiment and will not be repeated here.

[0137] In some embodiments, as Figure 9 As shown, another method for determining formation pressure includes:

[0138] Step S101, using a pressure prediction method based on undercompaction genesis theory to obtain a first formation pressure in a target area;

[0139] Step S102c: Correct the first formation pressure according to the influence of the distance from the fault on the formation pressure.

[0140] In some embodiments, another method for determining formation pressure is provided, including:

[0141] Using a pressure prediction method based on undercompaction genesis theory, the first formation pressure in the target area is obtained;

[0142] The first formation pressure is corrected according to the influence of the burial depth on the formation pressure.

[0143] In response to the problem that conventional pressure prediction methods based on undercompaction genesis theory are difficult to adapt to the prediction of formation pressure in complex structural areas, the present invention proposes a method that further considers the influence of different structural elements on the formation pressure on the basis of predicting the formation pressure based on the undercompaction genesis mechanism, thereby realizing formation pressure structural correction and improving the accuracy of formation pressure prediction in complex structural areas.

[0144] Example 5

[0145] Based on the foregoing embodiments, an embodiment of the present application provides a device for determining formation pressure. The modules included in the device and the sub-modules included in each module can be implemented by a processor in a computer device; of course, they can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit (CPU), a microprocessor (MPU), a digital signal processor (DSP) or a field programmable gate array (FPGA), etc.

[0146] The embodiment of the present application provides a device for determining formation pressure. Figure 10 A schematic diagram of a structure of a device for determining formation pressure provided in an embodiment of the present application is shown in FIG. Figure 10 As shown, the formation pressure determination device 500 includes:

[0147] An acquisition module 501 is configured to acquire a first formation pressure in a target area, where the first formation pressure is obtained using a pressure prediction method based on undercompaction genesis theory;

[0148] The correction module 502 is configured to correct the first formation pressure according to the influence of the structural elements of the target area on the formation pressure.

[0149] In some embodiments, as Figure 11 As shown, the correction module 502 includes:

[0150] The first correction submodule 5021 is configured to calculate a first impact of the compression structure on the formation pressure by introducing relative compression structure stress and a structural pressure factor according to the compression structure existing in the target area;

[0151] The second correction submodule 5022 and the third correction submodule 5023 divide the target area into a plurality of different pressure systems according to the structural units, and respectively calculate, for each pressure system, a second influence amount and a third influence amount of the distance and burial depth on the formation pressure based on the influence of the distance from the fault and the burial depth on the formation pressure;

[0152] The formation pressure determination submodule 5024 is configured to determine the formation pressure of the target area after correction for structural element influences based on the first influence amount, the second influence amount, and the third influence amount in a weighted summation manner.

[0153] The overpressure mechanism of tectonic origin can be explained by the unit cube model. If the compression is caused by the horizontal compression stress of the structure (such as folding), the direction of the maximum principal stress is horizontal, but perpendicular to the direction of the minimum principal stress. For general sedimentary compaction, the vertical upward pressure of the overlying strata can be decomposed into the effective stress borne by the rock skeleton and the fluid pressure borne by the fluid. If the fluid partially bears the force that should be borne by the rock skeleton, the sediment will be undercompacted and the pressure therein will be overpressure. After the compression tectonic action occurs, the tectonic stress will cause lateral compaction of the rock, compressing the rock skeleton and increasing the fluid pressure. The size of the fluid pressure increment depends on the degree of closure and openness of the hydrodynamic system. Therefore, the relative compression tectonic stress formation pressure correction amount (the first influencing amount) ΔP Q It can be expressed as:

[0154] ΔP Q =α*σ T +exp(b-φ)

[0155] Where α is the contribution rate of compression structure to formation pressure, σ T is the compressive tectonic stress, φ is the porosity, and b is a constant.

[0156] α is often replaced by curvature. This is because curvature attributes describe geometric variations in geological bodies and are sensitive to bending, folding, cracking, and faulting in rock formations. Larger absolute values ​​of curvature attributes indicate greater formation curvature and compressive stress. Curvature attributes are preferably extracted from structural interpretation horizons, as they are easier to obtain and offer higher accuracy.

[0157] The magnitude of the ground stress in the compressional tectonic area is not constant, but changes with the depth of the stratum. A large number of drilling practices and studies have shown that in areas with severe compression, the magnitude of the ground stress change in the shallow layer is greater than that in the deep stratum. The law of the change of compressional tectonic stress with depth can be expressed as:

[0158]

[0159] Where, σ T is the compression tectonic stress, unit: MPa; σ Tmax is the maximum tectonic stress, unit: MPa; H is the depth, unit: m; H0 is the critical depth, unit: m; α is the coefficient, dimensionless.

[0160] The effect of the distance from a fault on the formation pressure can be expressed as:

[0161]

[0162] Where ΔP D1 are the impact of a certain fault on the formation pressure, dis_DC1 is the distance from the fault; the second impact is the sum of the impacts of multiple faults in the target area on the formation pressure.

[0163] The third influence quantity is:

[0164] ΔP T =β*time+ε,

[0165] Where ΔP T is the third influence quantity caused by the influence of burial depth on formation pressure, time is time, and β and ε are constants.

[0166] The formation pressure in the target area after correction considering the influence of structural elements is:

[0167] P M =P+a q *ΔP Q +a d *ΔP D +a t *ΔP T

[0168] PM is the corrected formation pressure, P is the first formation pressure without considering the structural influence, ΔP Q is the first influence of the compression structure on the formation pressure, ΔP D is the second influence of the fault on the formation pressure, ΔP T is the third influence of burial depth on formation pressure, a q 、a d 、a t are correction coefficients for the first influence amount, the second influence amount, and the third influence amount, respectively.

[0169] The embodiment of the present invention proposes a formation pressure determination device that considers the influence of different structural elements on the formation pressure, thereby realizing formation pressure structural correction, which can improve the formation pressure prediction accuracy in complex structural areas.

[0170] It should be noted that, in the embodiment of the present application, if the above-mentioned method for determining formation pressure is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a magnetic disk, or an optical disk. In this way, the embodiment of the present application is not limited to any specific combination of hardware and software.

[0171] Accordingly, an embodiment of the present application further provides a storage medium on which a computer program is stored, characterized in that when the computer program is executed by a processor, the steps in the method for determining formation pressure provided in the above embodiment are implemented.

[0172] Example 6

[0173] The embodiment of the present application provides a device for determining formation pressure; Figure 12 A schematic diagram of the structure of the formation pressure determination device provided in the embodiment of the present application is shown in FIG. Figure 12As shown, the formation pressure determination device 600 includes: a processor 601, at least one communication bus 602, a user interface 603, at least one external communication interface 604, and a memory 605. The communication bus 602 is configured to facilitate communication between these components. The user interface 603 may include a display screen, and the external communication interface 604 may include a standard wired interface and a wireless interface. The processor 601 is configured to execute a program for determining formation pressure stored in the memory to implement the steps of the formation pressure determination method provided in the above-described embodiment.

[0174] The description of the above display device and storage medium embodiments is similar to the description of the above method embodiments and has similar beneficial effects as the method embodiments. For technical details not disclosed in the computer device and storage medium embodiments of this application, please refer to the description of the method embodiments of this application for understanding.

[0175] It should be noted that the description of the above storage medium and device embodiments is similar to the description of the above method embodiments and has similar beneficial effects as the method embodiments. For technical details not disclosed in the storage medium and device embodiments of this application, please refer to the description of the method embodiments of this application for understanding.

[0176] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The above-mentioned serial numbers of the embodiments of the present application are for description only and do not represent the advantages and disadvantages of the embodiments.

[0177] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0178] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0179] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed across multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the scheme of this embodiment.

[0180] In addition, all functional units in the embodiments of the present application can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the above-mentioned integrated units can be implemented in the form of hardware or in the form of hardware plus software functional units.

[0181] Those skilled in the art will understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiments; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROMs), magnetic disks, optical disks, and other media that can store program codes.

[0182] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling a controller to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks or optical disks.

[0183] The above is merely an embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for determining formation pressure, characterized in that: include: Using a pressure prediction method based on undercompaction genesis theory, the first formation pressure in the target area is obtained; Correcting the first formation pressure according to the influence of structural elements of the target area on the formation pressure; The correcting the first formation pressure according to the influence of the structural elements of the target area on the formation pressure includes: According to the compression structure existing in the target area, by introducing relative compression structure stress and structure pressure factor, calculating the first impact of the compression structure on the formation pressure; The target area is divided into multiple different pressure systems according to the structural unit. The system calculates a second influence amount and a third influence amount of the distance and the burial depth on the formation pressure based on the influence of the distance from the fault and the burial depth on the formation pressure; The formation pressure of the target area after correction considering the influence of structural elements is determined based on a weighted summation method according to the first influence amount, the second influence amount and the third influence amount.

2. The method according to claim 1, characterized in that The first influence quantity is: in, is the contribution rate of the compression structure to the formation pressure, is the compressive structural stress, is the porosity, is a constant.

3. The method according to claim 2, characterized in that Contribution rate of the compression structure to the formation pressure is the curvature; and / or, the extrusion structural stress is obtained by the following formula: in, It is the compressive tectonic stress; is the maximum extrusion tectonic stress; for depth; is the critical depth, is the coefficient.

4. The method according to claim 1, wherein The effect of the distance from a fault on the formation pressure can be expressed as: in, are the impact of a certain fault on the formation pressure, is the distance from the fault; The second impact amount is the sum of the impacts of multiple faults in the target area on the formation pressure.

5. The method according to claim 1, wherein The third influence amount is: ， in, is the third influence quantity caused by the influence of burial depth on formation pressure, For time, is a constant.

6. The method according to claim 1, wherein The formation pressure in the target area after correction considering the influence of structural elements is: PM is the corrected formation pressure, P is the first formation pressure without considering the structural influence, is the first impact of the squeeze structure on the formation pressure, is the second impact of the fault on the formation pressure, is the third influence of burial depth on formation pressure, aq, ad, and at are correction coefficients of the first influence, the second influence, and the third influence, respectively.

7. A device for determining formation pressure, characterized in that: include: an acquisition module, configured to acquire a first formation pressure in a target area, wherein the first formation pressure is obtained by using a pressure prediction method based on an undercompaction genesis theory; a correction module, configured to correct the first formation pressure according to the influence of structural elements of the target area on the formation pressure; The correction module includes: A first correction submodule is configured to calculate a first impact of the compression structure on the formation pressure by introducing relative compression structure stress and a structural pressure factor according to the compression structure existing in the target area; The second correction submodule and the third correction submodule divide the target area into a plurality of different pressure systems according to the structural units, and respectively calculate, for each pressure system, a second influence amount and a third influence amount of the distance and the burial depth on the formation pressure according to the influence of the distance from the fault and the burial depth on the formation pressure; The formation pressure determination submodule is used to determine the formation pressure of the target area after correction considering the influence of structural elements based on the weighted summation method according to the first influence amount, the second influence amount and the third influence amount.

8. A device for determining formation pressure, characterized in that: The method comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method for determining the formation pressure according to any one of claims 1 to 6 is executed.

9. A storage medium, characterized in that: The computer program stored in the storage medium can be executed by one or more processors and can be used to implement the method for determining formation pressure as claimed in any one of claims 1 to 6.

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