Method for analyzing formation conditions of high-pressure brine layer

Abstract

The invention provides a method for analyzing formation conditions of a high-pressure brine layer, which relates to the technical field of well drilling and comprises the following steps of: analyzing a relationship between a well drilling track and a fault zone according to a vertical section of an earthquake coherence body, and determining a migration channel for development of the brine layer; analyzing a local structural form and a combination mode of the migration channel by using a seismic coherent body horizontal slice, and determining a crack dense zone; and in combination with the seismic diffracted wave slice and the seismic coherent body horizontal slice, determining a spatial configuration relationship between the fracture dense zone and the migration channel to obtain a salt water layer prediction result. According to the method, by analyzing the vertical communication condition with deep formation water, the local fracture development condition near the fracture zone and the micro-fracture dense zone and fault configuration condition, the problems of a saline migration channel, a fracture development part and the configuration relation between the micro-fracture dense zone and the channel are solved in sequence; the purpose of predicting brine layer distribution based on new knowledge formed by the high-pressure brine layer is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling, and is applied to predicting the distribution of high-pressure salt water layers in formations at different depths before and / or during drilling, and specifically to a method for analyzing the formation conditions of high-pressure salt water layers. Background Art

[0002] The successful exploration of fault-karst oil reservoirs in the northern Tarim Basin lies in the fact that the activity of the strike-slip fault zone not only leads to the development of carbonate cave-fracture reservoirs distributed along the fault zone, but also the nearly vertical fault system formed by it becomes an efficient drainage system between the reservoir and the deep source rock, which leads to the deployment of exploration wells along the strike-slip fault zone.

[0003] However, due to the lack of in-depth understanding of the distribution patterns of high-pressure brine layers, "encounters" often occur during the drilling process, leading to drilling accidents such as well wall collapse in the brine-producing area, and even necessitating backfill and side drilling, which not only increases the risk level of well control, but also greatly prolongs the drilling cycle.

[0004] In view of the problems in the prior art, the present invention provides a method for analyzing the formation conditions of a high-pressure salt water layer. Summary of the invention

[0005] In view of the problems of the current prior art, the present invention provides a method for analyzing the formation conditions of a high-pressure salt water layer, the method comprising:

[0006] Based on the vertical section of the seismic coherence body, the relationship between the drilling trajectory and the fault zone is analyzed to determine the migration channel of the salt water layer;

[0007] By using horizontal slices of seismic coherence volume, the local structural morphology and combination mode of the migration channel are analyzed to determine the fracture-intensive zone;

[0008] The spatial configuration relationship between the fracture intensive zone and the migration channel is determined by combining the seismic diffraction wave slice and the horizontal slice of the seismic coherence body to obtain the salt water layer prediction result.

[0009] According to one embodiment of the present invention, the migration channel is determined by the following steps:

[0010] Based on the vertical profile of the seismic coherence body, the vertical development characteristics of the fault zone related to the drilling trajectory are determined. If a high-angle strike-slip fault exists on one or both sides of the drilling trajectory, the high-angle strike-slip fault is determined as the migration channel.

[0011] According to one embodiment of the present invention, the vertical development characteristics of the fault zone related to the drilling trajectory are identified by using the vertical profile of the seismic coherence body, and when calculating the coherence value:

[0012]

[0013] Where S(τ,p,q) is the coherence value; τ is the time window, which contains J data; p and q are the apparent dip angles in the x and y directions, respectively; u is the seismic data; Δt is the sampling rate; ±K is the number of samples above and below the time point t, and k represents the kth sample point; (x j ,y j ) is the plane coordinate position of the jth analysis point.

[0014] According to one embodiment of the present invention, the crack-intensive zone is determined by the following steps:

[0015] By using the horizontal slices of the seismic coherence volume, the local fracture structure morphology and combination mode near the migration channel in different layers and depths of the target well are analyzed to determine the fracture intensive zone.

[0016] According to one embodiment of the present invention, the fracture disappearance point, the fracture butt zone and the fracture direction change point are determined as the crack intensive zone.

[0017] According to one embodiment of the present invention, the seismic diffraction wave slice is obtained by the following steps:

[0018] Decompose the original seismic data in the form of plane waves to obtain predicted reflection waves;

[0019] The predicted reflection wave is subtracted from the original seismic data to obtain a residual wave field including a diffraction wave, so as to obtain the seismic diffraction wave slice.

[0020] According to one embodiment of the present invention, the residual wave field of the diffracted wave is obtained by the following expression:

[0021] C(Z t ,Z x )=A(Z t ,Z x )B(1 / Z t )=B(1 / Z t )-Z x B(Z t )

[0022]

[0023]

[0024] Where: C(Z t ,Z x ) is the residual wave field of the diffraction wave; B(Z t ) is an all-pass digital filter; Z x It is formed by the Z transformation of the spatial sample direction; Zt is the Z-transform form of the time sample direction; σ is the formation dip.

[0025] According to one embodiment of the present invention, the salt water layer prediction result is obtained by the following steps:

[0026] The horizontal slices of the seismic coherence volume and the diffraction wave slices are superimposed and displayed, and the area where the diffraction wave energy around the drilling trajectory is higher than a preset value, is in the crack-intensive zone, and is adjacent to the migration channel is determined as the predicted brine layer.

[0027] According to another aspect of the present invention, a storage medium is provided, which contains a series of instructions for executing the method steps as described in any one of the above.

[0028] According to another aspect of the present invention, there is also provided a high-pressure salt water layer formation condition analysis device, which performs a high-pressure salt water layer formation condition analysis method as described in any one of the above items, and the device comprises:

[0029] Migration channel identification module, which is used to analyze the relationship between the drilling trajectory and the fault zone based on the vertical section of the seismic coherence body, and determine the migration channel of the salt water layer;

[0030] A fracture-intensive zone identification module is used to analyze the local structural morphology and combination mode of the migration channel by using horizontal slices of the seismic coherence volume to determine the fracture-intensive zone;

[0031] The saltwater layer prediction module is used to determine the spatial configuration relationship between the crack-intensive zone and the migration channel by combining the seismic diffraction wave slice and the seismic coherence volume horizontal slice to obtain the saltwater layer prediction result.

[0032] The present invention provides a method for analyzing the formation conditions of a high-pressure salt water layer. Compared with the prior art, the present invention has the following advantages: by analyzing the vertical communication conditions with deep formation water, the local fracture development conditions near the fault zone, and the configuration conditions of the micro-fracture dense zone and the fault, the present invention solves the problems of the configuration relationship between the salt water migration channel, the fracture development location, and the micro-fracture dense zone and the channel in turn, thereby achieving the purpose of predicting the distribution of the salt water layer based on the new understanding of the formation of the high-pressure salt water layer.

[0033] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0035] Figure 1 A flowchart showing a method for analyzing conditions for forming a high-pressure saltwater layer according to an embodiment of the present invention is shown;

[0036] Figure 2 A high-pressure saltwater layer distribution prediction flow chart according to an embodiment of the present invention is shown;

[0037] Figure 3 A vertical cross-section of a seismic coherence volume through a well according to an embodiment of the present invention is shown;

[0038] Figure 4 A time slice diagram of a seismic coherence volume according to an embodiment of the present invention is shown;

[0039] Figure 5 A seismic coherence volume and a diffraction wave superposition display diagram according to an embodiment of the present invention are shown.

[0040] In the accompanying drawings, the same reference numerals are used for the same components. In addition, the accompanying drawings are not drawn according to the actual scale. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0042] The prior art (CN211648045U) discloses a safe drilling system for preventing the collapse of water-sensitive formations above the high-pressure salt water layer, which includes wellhead equipment, in-hole drilling tools, a first injection pipeline, a second injection pipeline, a first return pipeline, and a second return pipeline; after drilling into the high-pressure salt water layer, heavy mud is injected into the wellbore annulus through the first injection pipeline to form a heavy mud cap, so that the annular liquid column pressure balances the high-pressure salt water layer pressure. At this time, the liquid column pressure in the drill string is less than the high-pressure salt water layer pressure. Under the pressure of the high-pressure salt water layer itself, the salt water returns through the drill bit water hole and the drill string to prevent the salt water from returning through the annulus and contacting the well wall. During this process, drilling can continue, and the returned high-pressure salt water carries rock cuttings back to the wellhead.

[0043] The prior art (CN116006119A) discloses a high-pressure salt water layer cementing inverted slurry column cement slurry system and its preparation method. The inverted slurry column cement slurry system consists of a lead slurry and a tail slurry; the lead slurry has a density of 2.2g / cm 3 ~2.45g / cm 3 Cement slurry system within the range; tail slurry has a density of 1.9g / cm 3 ~2.0g / cm3 Cement slurry system within the range; a method for preparing a cement slurry system for an inverted slurry column includes preparing a cement slurry system having a density of 2.2 g / cm 3 ~2.45g / cm 3 The cement slurry system in the range is used as the lead slurry of the cement slurry system for cementing inversion column of high-pressure salt water layer; the preparation density is 1.9g / cm 3 ~2.0g / cm 3 Cement slurry systems within the range.

[0044] The prior art (CN112980408B) discloses a high-pressure salt water layer fracture type leakage plugging agent, which comprises the following steps: accurately weighing 0.15-0.21 parts of anhydrous sodium carbonate and dissolving it in 100 parts of water, slowly adding 5-7 parts of bentonite under stirring at a speed of 500-1000 rpm, stirring for 1 hour, standing for 24 hours to prepare a bentonite-based slurry, slowly adding 1-2 parts of a chemical gel material under a speed of 500-1000 rpm, stirring for 0.5-1 hour, and then sequentially adding 5-7 parts of a physical gel material, 15-20 parts of a fast water loss material, 2-4 parts of a delayed water absorption and expansion material, 10-14 parts of a rigid material, and 0.1-0.2 parts of a fiber, and after all of the additions are completed, stirring is continued at a speed of 1000-1500 rpm for 1-1.5 hours to obtain a high-pressure salt water layer fracture type leakage plugging agent.

[0045] The prior art (CN108798565A) discloses a high-pressure salt water layer fine pressure control drainage system and a pressure control drainage method, including a high-pressure salt water discharge device: including a casing, a drill pipe inserted into the casing, a drill pipe with a packer installed with a throttle valve, the drill pipe is located on a drilling platform and is connected to a high-pressure outlet pipeline through a continuous tubing blowout box, and is connected to a liquid-gas separator through a medium-pressure outlet pipeline and a fine pressure control throttle skid; a high-pressure salt water prevention structure device: including a continuous tubing, which is connected to a mud tank and a salt inhibitor tank through a continuous tubing vehicle, an injection head and a blowout preventer; a ground pressure control throttle device: including a fine pressure control throttle skid installed on the medium-pressure outlet pipeline, the fine pressure control throttle skid transmits the collected pressure and flow data to a computer control system through a PLC system, and the computer control system controls the ground pressure according to the collected data; a formation pressure measuring device: including a well team throttle skid, which is connected to a liquid-gas separator through a well team throttle pipeline.

[0046] However, the above four prior arts do not mention the analysis of the formation conditions of the high-pressure brine layer, nor can they predict the distribution of the high-pressure brine layer in formations at different depths before and / or during drilling.

[0047] The prior art (CN101942992B) discloses a method for predicting the pore pressure of a regional high-pressure salt water layer using the curvature of a geological structure surface. The method predicts the pore pressure of a regional high-pressure salt water layer using the curvature of a geological structure surface by determining the regional distribution law and structural contour map of the salt-gypsum layer through seismic data and actual drilling logging data, establishing a regional elevation equation on the geological structure contour map using the harmonic trend surface method and determining the principal curvature of any point in the structural area, calculating the principal stress at any point, establishing a pore pressure prediction model at any point, and determining the pore pressure of the high-pressure salt water layer, so as to provide a scientific basis for determining the safe drilling fluid density when determining the on-site construction during the drilling design, so as to effectively prevent the well wall from collapsing and prevent the occurrence of complex situations underground.

[0048] The prior art (CN101936157B) provides a method for detecting the pore pressure of a high-pressure salt water layer using logging data. The method detects the pore pressure of a high-pressure salt water layer based on the measured logging data through the acoustic time difference, natural potential, natural gamma logging response characteristics based on sedimentary characteristics and the pore pressure surface of the high-pressure salt water layer, so as to provide a scientific basis for determining the safe drilling fluid density during drilling design, so as to effectively prevent the occurrence of complex and other serious accidents in the salt water layer during construction.

[0049] However, the above two prior arts only mention the prediction or detection of the pore pressure of the high-pressure brine layer, and do not mention the analysis of the formation conditions of the high-pressure brine layer, nor can they predict the distribution of the high-pressure brine layer in the formation at different depths before and / or during drilling.

[0050] The fundamental reason for the "encounter" in the high-pressure saline layer during the drilling process is the lack of in-depth understanding of the formation mechanism and distribution law of the high-pressure saline layer. Therefore, it is impossible to adopt reasonable technical means and methods to predict its distribution. It is necessary to use new understanding and new results of the formation mechanism of high-pressure saline layers to guide the prediction of the distribution of saline layers before drilling, so as to achieve the purpose of reducing the complexity of drilling.

[0051] The present invention realizes that the high-mineralization brine that intrudes along the fault zone is usually stored in the micro-fracture zone near the fault zone, and the formation and development of these micro-fracture zones are mainly controlled by the regional structure, local structure and their combined characteristics. In addition, not all micro-fracture zones contain brine layers, but only micro-fracture zones that are interconnected with large strike-slip faults are likely to accumulate brine.

[0052] In view of the above-mentioned defects of the prior art, the present invention relates to a pre-drilling distribution prediction based on geophysical analysis of the formation conditions of high-pressure brine layers. The present invention takes the new understanding that high-pressure brine layers originate from deep, are controlled by structures and are distributed along fault zones as its theoretical basis. The present invention mainly uses seismic coherence technology and diffraction wave technology to predict the distribution of high-pressure brine layers developed in different geological eras and different lithology combinations underground in the well being drilled, thereby providing guidance for the reasonable allocation of drilling fluid density and the optimization of wellbore structure.

[0053] It should be noted that the definition of "high pressure" in high-pressure saline layers is different in each drilling area. In engineering applications, "high pressure" refers to pressure that exceeds the normal formation pressure at the depth.

[0054] Figure 1 A flowchart of the steps of a method for analyzing the formation conditions of a high-pressure salt water layer according to an embodiment of the present invention is shown.

[0055] like Figure 1 As shown, in step S1, the relationship between the drilling trajectory and the fault zone is analyzed based on the vertical section of the seismic coherence body to determine the migration channel of the salt water layer.

[0056] In one embodiment, in step S1, the migration channel is determined by the following steps: based on the vertical profile of the seismic coherence body, the vertical development characteristics of the fault zone related to the drilling trajectory are determined; if there are high-angle strike-slip faults on one or both sides of the drilling trajectory, the high-angle strike-slip faults are determined as the migration channel.

[0057] It should be noted that the drilling trajectory may refer to the designed drilling trajectory before drilling or the actual drilling trajectory during drilling. The present invention can not only predict the brine layer during the drilling process, but also predict the distribution of high-pressure brine layers in formations at different depths before drilling begins.

[0058] The coherence volume is a three-dimensional seismic data volume. The similarity between the waveform of the analysis point and the adjacent waveform within the hour window at each sample point in each channel is obtained to form a three-dimensional data volume that represents the coherence. The present invention uses the coherence change of seismic signals to accurately describe the spatial distribution of the fault system and its combined characteristics.

[0059] In one embodiment, Figure 2 As shown in the figure, the vertical communication condition with deep formation water is identified by the vertical section of the seismic coherence body. Specifically, the vertical development characteristics of the fault zone related to the drilling trajectory are identified by the vertical section of the seismic coherence body. When calculating the coherence value, the time window τ is first defined. If there are J data in the time window, and the coordinates of the analysis point are (x, y), then:

[0060]

[0061] Where S(τ,p,q) is the coherence value; τ is the time window, which contains J data; p and q are the apparent dip angles in the x and y directions, respectively; u is the seismic data; Δt is the sampling rate; ±K is the number of samples above and below the time point t, and k represents the kth sample point; (x j ,y j ) is the plane coordinate position of the jth analysis point.

[0062] In practical applications, the present invention can clearly see the vertical development characteristics of the fault zone related to the drilling trajectory by means of the vertical section of the seismic coherence body ( Figure 3 ), Figure 3 Nearly vertical high-angle strike-slip faults (for example, the angle with the horizontal direction is greater than or equal to 60 degrees and less than or equal to 90 degrees) have developed on both sides of Well A. These two vertical faults have become good channels for the upward migration of deep high-mineralization formation water.

[0063] It should be noted that the angle range for determining a high-angle strike-slip fault can be changed according to actual needs, and the present invention does not limit this.

[0064] like Figure 1 As shown, in step S2, the local structural morphology and combination mode of the migration channel are analyzed by using the horizontal slice of the seismic coherence volume to determine the fracture intensive zone.

[0065] In one embodiment, in step S2, the fracture-intensive zone is determined by the following steps: using horizontal slices of the seismic coherence volume, the local fracture structural morphology and combination mode near the migration channel in different layers and different depths of the target well are analyzed to determine the fracture-intensive zone. Further, the fracture disappearance point, the fracture butt zone and the fracture trend change point are determined as the fracture-intensive zone.

[0066] The present invention believes that the salt water intruding along the vertical high-angle strike-slip fault must be enriched in the micro-crack zone generated by the fault activity near the fault zone. Since there are great differences in the development morphology and combination mode at different parts and different structural layers of the same fault, of course, this difference is a reflection of the characteristics of the tectonic stress field, and controls the differences in the development characteristics and development scale of cracks and micro-cracks.

[0067] like Figure 2 As shown in the figure, the local fracture development conditions near the fault zone are analyzed. The horizontal slices of the seismic coherence technology used in the present invention can analyze the local structural morphology and combination mode in different layers and different depths of the well. Generally speaking, the fracture disappearance point and the fracture butt joint zone ( Figure 4) and areas where the fault direction changes sharply, the drastic changes in the stress field often induce the development of larger-scale microcracks (zones), which provide a good storage space for the brine migrating from deep along the fault zone.

[0068] Although the horizontal slices of the seismic coherence technology can be used to conduct structural combination analysis and further determine the overall enrichment and development degree of the fracture-dense zone, its density is often not uniform, resulting in the distribution of the salt water layer not being a continuous distribution but showing the characteristics of local enrichment. At the same time, only those micro-crack-dense areas that communicate with the fault zone are conducive to the enrichment of salt water. The present invention combines the use of diffraction wave technology to analyze the spatial distribution of the fracture-dense zone and the spatial configuration relationship between the fracture zone and the fault.

[0069] like Figure 1 As shown, in step S3, the spatial configuration relationship between the fracture intensive zone and the migration channel is determined by combining the seismic diffraction wave slice and the seismic coherence volume horizontal slice to obtain the salt water layer prediction result.

[0070] In one embodiment, in step S3, seismic diffraction wave slices are obtained by the following steps: decomposing original seismic data in the form of plane waves to obtain predicted reflection waves; subtracting the predicted reflection waves from the original seismic data to obtain a residual wave field containing diffraction waves to obtain seismic diffraction wave slices.

[0071] Specifically, the reflection wave results are limited by wavelength, and the resolution is often difficult to meet the requirements of micro-structural description. The development of diffraction waves in seismic data is often related to small-scale geological bodies. The minimum resolution of diffraction waves in seismic data is 1 / 4 wavelength to 1 / 40 wavelength. It is an important method for fine description of small-scale faults. There is effective diffraction information in the post-stack data, and these residual diffraction information can well reflect the spatial variation of the density of microcracks. Plane wave decomposition (PWD) was proposed by Claerbout in 1992. It decomposes seismic data in the form of plane waves and can better predict reflection waves. The present invention uses the original seismic data minus the predicted reflection waves to achieve the purpose of separating the reflection wave and diffraction wave fields.

[0072] In one embodiment, the residual wave field of the diffracted wave is obtained by the following expression:

[0073] C(Z t ,Z x )=A(Z t ,Z x )B(1 / Z t )=B(1 / Z t )-Z x B(Z t )

[0074]

[0075]

[0076] Where: C(Z t ,Z x ) is the residual wave field of the diffraction wave; B(Z t ) is an all-pass digital filter; Z x It is formed by the Z transformation of the spatial sample direction; Z t is the Z-transform form of the time sample point direction; σ is the formation dip.

[0077] In one embodiment, in step S3, the saltwater layer prediction result is obtained by the following steps: superimposing and displaying the horizontal slice of the seismic coherence volume and the diffraction wave slice, and determining the area around the drilling trajectory where the diffraction wave energy is higher than the preset value, is in the crack-intensive zone, and is adjacent to the migration channel as the predicted saltwater layer. It should be noted that those skilled in the art can determine the specific value range of the preset value as needed, and the present invention does not limit the value range of the preset value.

[0078] like Figure 2 As shown in the figure, after determining the overall enrichment of fractures using horizontal slices of the seismic coherence volume, it is necessary to analyze the development characteristics of the microfracture dense zone and further analyze the configuration relationship between the microfracture dense zone and the fault zone. Specifically, the spatial distribution of reflection wave event axes can be effectively predicted by the local plane wave decomposition technology, and the prediction of multiple reflection event axes can be realized in the theoretical algorithm. After obtaining the predicted reflection wave field, the reflection wave field is removed from the wave field to obtain the residual wave field containing the diffraction wave. Figure 5 The seismic coherence volume and diffraction wave superposition display are given. Figure 5 The diffraction wave energy on the right side of Well A is relatively strong, micro-fractures are densely developed, and it is close to the vertical high-angle fault on the left side, which is a place where brine is easy to accumulate.

[0079] Figure 2 A high-pressure saltwater layer distribution prediction flow chart according to an embodiment of the present invention is shown.

[0080] Based on the new understanding of the formation mechanism of saline layers, the present invention establishes a technical process for predicting the distribution of high-pressure saline layers based on the vertical communication conditions with deep formation water, the development conditions of local fractures near the fault zone, and the configuration conditions of micro-fracture dense zones and faults. Figure 2 ), these three conditions are closely linked and connected. The first two conditions are determined by vertical sections and horizontal slices of the seismic coherence body, and the last one is achieved by seismic diffraction wave technology.

[0081] The present invention relates to a pre-drilling distribution prediction based on geophysical analysis of the formation conditions of high-pressure salt water layers, which can be used to predict the distribution of high-pressure salt water layers in formations at different depths before or during drilling. The specific technical process includes the following three aspects:

[0082] like Figure 2 As shown, in terms of vertical communication conditions with deep formation water, the present invention uses the vertical section of seismic coherence technology to analyze the relationship between the drilling trajectory and the high-angle strike-slip fault, which can solve the problem of migration channels for the development of salt water layers.

[0083] like Figure 2 As shown, in terms of the local crack development conditions near the fault zone, the present invention uses horizontal slices of seismic coherence technology to analyze the local structural morphology and combination mode of the fault, which can solve the problem of the degree of crack development.

[0084] like Figure 2 As shown, in terms of the configuration conditions of micro-crack dense zones and faults, the present invention uses seismic diffraction wave technology to study the distribution characteristics of micro-crack dense zones, and combines coherent body slices for superposition display, which can solve the problem of the spatial configuration relationship between the distribution of crack dense zones and faults.

[0085] The present invention can predict the distribution of high-pressure salt water layers by analyzing the formation conditions of the high-pressure salt water layers in the above three aspects, provide guidance for drilling fluid design, and reduce the occurrence of drilling accidents and well control risks.

[0086] The high-pressure saltwater layer formation condition analysis method provided by the present invention can also be used in conjunction with a computer-readable storage medium, on which a computer program is stored, and the computer program is executed to run the high-pressure saltwater layer formation condition analysis method. The computer program can run computer instructions, and the computer instructions include computer program code, which can be in source code form, object code form, executable file or some intermediate form, etc.

[0087] Computer-readable storage media may include: any entity or device that can carry computer program code, recording media, USB flash drives, mobile hard disks, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0088] It should be noted that the content contained in computer-readable storage media can be appropriately increased or decreased based on the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, based on legislation and patent practices, computer-readable storage media do not include electrical carrier signals and telecommunications signals.

[0089] According to another aspect of the present invention, a high-pressure salt water layer formation condition analysis device is provided, which executes a high-pressure salt water layer formation condition analysis method. The device includes: a migration channel identification module, a fracture intensive zone identification module, and a salt water layer prediction module.

[0090] The migration channel identification module is used to analyze the relationship between the drilling trajectory and the fault zone based on the vertical section of the seismic coherence body, and determine the migration channel of the salt water layer; the fracture intensive zone identification module is used to analyze the local structural morphology and combination mode of the migration channel using the horizontal slice of the seismic coherence body, and determine the fracture intensive zone; the salt water layer prediction module is used to combine the seismic diffraction wave slice and the horizontal slice of the seismic coherence body to determine the spatial configuration relationship between the fracture intensive zone and the migration channel, so as to obtain the salt water layer prediction result.

[0091] The present invention involves three aspects: vertical communication conditions with deep formation water, local fracture development conditions near fault zones, and configuration conditions of micro-fracture intensive zones and faults. The invention comprehensively utilizes vertical profiles of seismic coherence bodies, horizontal slicing technology, and seismic diffraction wave technology to predict the distribution of high-pressure salt water layers.

[0092] Among them, the vertical section of the seismic coherence technology is used to analyze the relationship between the drilling trajectory and the high-angle strike-slip fault, which solves the problem of the migration channel of the salt water layer. The horizontal slice of the seismic coherence technology is used to analyze the local structural morphology and combination of the fault, which solves the problem of the degree of fracture development. The distribution characteristics of the micro-fracture dense zone are studied by using the seismic diffraction wave technology, and combined with the coherence slice superposition display, the problem of the spatial configuration relationship between the distribution of the fracture dense zone and the fault is solved.

[0093] In summary, the present invention provides a method for analyzing the formation conditions of high-pressure salt water layers. Compared with the prior art, the present invention has the following advantages: through the analysis of the vertical communication conditions with deep formation water, the local fracture development conditions near the fault zone, and the configuration conditions of the micro-fracture dense zone and the fault, the present invention solves the problems of the configuration relationship between the brine migration channel, the fracture development location, and the micro-fracture dense zone and the channel in turn, thereby achieving the purpose of predicting the distribution of salt water layers based on the new understanding of the formation of high-pressure salt water layers.

[0094] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0095] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0096] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0097] Certain terms are used throughout this application document to indicate specific system components. As those skilled in the art will recognize, different names can usually be used to indicate the same components, so this application document is not intended to distinguish those components that are only different in name but not in function. In this application document, the terms "comprise", "include" and "have" are used in an open form, and therefore should be interpreted as meaning "including but not limited to...". In addition, the terms "substantially", "substantially" or "approximately" that may be used in this article relate to the tolerances of the corresponding terms accepted by the industry. The term "coupling" as may be used in this article includes direct coupling and indirect coupling via other components, elements, circuits, or modules, wherein for indirect coupling, the components, elements, circuits, or modules between them do not change the information of the signal but can adjust its current level, voltage level, and / or power level. Inferred coupling (for example, one of the elements is coupled to another element by inference) includes direct and indirect coupling between two elements in the same way as "coupling".

[0098] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" appearing in various places throughout the specification do not necessarily refer to the same embodiment.

[0099] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0100] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A method for analyzing the formation conditions of a high-pressure salt water layer, characterized in that: The method comprises: Based on the vertical section of the seismic coherence body, the relationship between the drilling trajectory and the fault zone is analyzed to determine the migration channel of the salt water layer; By using horizontal slices of seismic coherence volume, the local structural morphology and combination mode of the migration channel are analyzed to determine the fracture-intensive zone; The spatial configuration relationship between the fracture intensive zone and the migration channel is determined by combining the seismic diffraction wave slice and the horizontal slice of the seismic coherence body to obtain the salt water layer prediction result.

2. A method for analyzing the formation conditions of a high-pressure salt water layer according to claim 1, characterized in that: The migration pathway is determined by the following steps: Based on the vertical profile of the seismic coherence body, the vertical development characteristics of the fault zone related to the drilling trajectory are determined. If a high-angle strike-slip fault exists on one or both sides of the drilling trajectory, the high-angle strike-slip fault is determined as the migration channel.

3. A method for analyzing the formation conditions of a high-pressure salt water layer as claimed in claim 2, characterized in that: The vertical development characteristics of the fault zone related to the drilling trajectory are identified by using the vertical section of the seismic coherence body. When calculating the coherence value: Where S(τ,p,q) is the coherence value; τ is the time window, which contains J data; p and q are the apparent dip angles in the x and y directions, respectively; u is the seismic data; Δt is the sampling rate; ±K is the number of samples above and below the time point t, and k represents the kth sample point; (x j ,y j ) is the plane coordinate position of the jth analysis point.

4. A method for analyzing the formation conditions of a high-pressure salt water layer according to any one of claims 1 to 3, characterized in that: The crack-intensive zone is determined by the following steps: By using the horizontal slices of the seismic coherence volume, the local fracture structure morphology and combination mode near the migration channel in different layers and depths of the target well are analyzed to determine the fracture intensive zone.

5. A method for analyzing the formation conditions of a high-pressure salt water layer as claimed in claim 4, characterized in that: The point where the fault disappears, the fault butt zone and the point where the fault direction changes are determined as the crack-intensive zone.

6. A method for analyzing the formation conditions of a high-pressure salt water layer according to any one of claims 1 to 5, characterized in that: The seismic diffraction wave slice is obtained by the following steps: Decompose the original seismic data in the form of plane waves to obtain predicted reflection waves; The predicted reflection wave is subtracted from the original seismic data to obtain a residual wave field including a diffraction wave, so as to obtain the seismic diffraction wave slice.

7. A method for analyzing the formation conditions of a high-pressure salt water layer according to claim 6, characterized in that: The residual wave field of the diffracted wave is obtained by the following expression: C(Z t ,Z x )=A(Z t ,Z x )B(1 / Z t )=B(1 / Z t )-Z x B(Z t ) Where: C(Z t ,Z x ) is the residual wave field of the diffraction wave; B(Z t ) is an all-pass digital filter; Z x It is formed by the Z transformation of the spatial sample direction; Z t is the Z-transform form of the time sample point direction; σ is the formation dip.

8. A method for analyzing the formation conditions of a high-pressure salt water layer according to any one of claims 1 to 7, characterized in that: The saltwater layer prediction result is obtained by the following steps: The horizontal slices of the seismic coherence volume and the diffraction wave slices are superimposed and displayed, and the area where the diffraction wave energy around the drilling trajectory is higher than a preset value, is in the crack-intensive zone, and is adjacent to the migration channel is determined as the predicted brine layer.

9. A storage medium, characterized in that: It contains a series of instructions for executing the method steps as claimed in any one of claims 1 to 8.

10. A device for analyzing conditions for formation of a high-pressure salt water layer, characterized in that: A method for analyzing the formation conditions of a high-pressure salt water layer according to any one of claims 1 to 8 is performed, wherein the device comprises: Migration channel identification module, which is used to analyze the relationship between the drilling trajectory and the fault zone based on the vertical section of the seismic coherence body, and determine the migration channel of the salt water layer; A fracture-intensive zone identification module is used to analyze the local structural morphology and combination mode of the migration channel by using horizontal slices of the seismic coherence volume to determine the fracture-intensive zone; The saltwater layer prediction module is used to determine the spatial configuration relationship between the crack-intensive zone and the migration channel by combining the seismic diffraction wave slice and the seismic coherence volume horizontal slice to obtain the saltwater layer prediction result.

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