Method and electronic equipment for characterizing the internal structure of carbonate rock fault-karst body by phase-controlled inversion

Abstract

The invention discloses a method and electronic device for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion. The method comprises: obtaining fault-karst seismic phases and fracture seismic phases respectively based on original seismic data; establishing a carbonate straight plate low-frequency model; obtaining a beaded seismic phase based on the straight plate low-frequency model; obtaining a phase-controlled low-frequency model based on the straight plate low-frequency model, the fault-karst seismic phase, the fracture seismic phase and the beaded seismic phase; obtaining a longitudinal wave impedance data body based on the phase-controlled low-frequency model; obtaining a porosity body of an effective reservoir body based on the longitudinal wave impedance data body, thereby characterizing the internal structure of a carbonate fault-karst body. The invention intuitively characterizes the reservoir distribution, development scale and connectivity inside the fault-karst body, and accurately predicts the scale of each reservoir body inside the fault-karst body, provides a reliable basis for well site deployment, improves the success rate of exploration and development drilling, and improves the efficiency of exploration and development, and the invention is not limited by region and has a wide range of applications.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas exploration, and in particular relates to a method and electronic equipment for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion. Background Art

[0002] In 2015, Luxinbian et al. proposed the concept of fault-karst trap, which mainly refers to the karst water seeping downward or upwelling along the fault direction to dissolve the broken zone, forming a karst fracture-cave system of different three-dimensional spaces, and a special type of trap formed under the cover of overlying marl or lateral dense limestone. The slope area outside Tahe in the Tarim Basin is affected by the cover of the Upper Ordovician strata. The development of karst fracture-cave bodies has a good matching relationship with fault zones and structural deformation. It has obvious fault-controlled karst characteristics. Dissolution and expansion with deep and large fault zones as the core make it a favorable zone for the development of karst fracture-cave bodies in the Middle and Lower Ordovician in the covered area. Under the guidance of the fault-karst reservoir model, with the deepening of exploration and development, the Shunbei large-scale fault-karst type oil and gas field was discovered. At present, 18 strike-slip fault zones related to the development of fault-karst bodies have been discovered and implemented in the Shunbei oil and gas field, with a resource scale of 17×10 8 t oil equivalent, demonstrating the good exploration and development prospects of Shunbei area.

[0003] Previous studies have shown that the main reservoir space inside the fault-karst body is caves related to strike-slip faults, structural high-angle fractures, and cavities dissolved along the fractures. Structural rupture is the main controlling factor for the development of fault-karst reservoirs, and dissolution transformation further promotes the development of reservoirs (Jiao Fangzheng 2018). The "beaded" high-energy seismic phase is strongly correlated with cave reservoirs, manifested as low P-wave impedance; dissolved pores are manifested as strong energy or blank reflection seismic phases, corresponding to lower P-wave impedance; fracture-type reservoir development sections have a good correlation with seismic attributes such as AFE and ant bodies.

[0004] Fault-karst bodies are geological bodies that combine fractures and caves. The description content includes the external morphology of the spatial distribution of the fault-karst boundary, as well as the internal structure of caves, dissolved pores and cracks connecting pores and caves in the fault-karst body. The development of reservoirs inside the fault-karst body is controlled by many factors, and the seismic wave field is complex. It is difficult to accurately and quantitatively describe the reservoirs inside the fault-karst body. The invention patent "Characterization Method of Fault-karst Body in Carbonate Rocks" proposed by Deng Guangxiao et al. (2017) mainly uses the underground P-wave impedance data obtained by conventional post-stack inversion as the background, hollows out the ant body attributes representing the development of fractures, and then superimposes the hollowed-out ant body attributes on the underground P-wave impedance to achieve the characterization of reservoirs and fractures. This method uses P-wave impedance attributes to describe the reservoir of the fault-karst body, and ant body attributes to describe the fractures. It only uses seismic attributes to describe the internal structure of the reservoir with pores and fractures inside the fault-karst body, and cannot describe the external morphology of the fault-karst body boundary.

[0005] The invention patent "Characterization Method of Internal Structure of Carbonate Fault-karst Body" proposed by Wen Huan et al. (2017) mainly uses post-stack conventional inversion to obtain underground P-wave impedance data, determine the P-wave impedance data threshold representing the fracture-cave reservoir, and perform hollowing and carving processing on the underground P-wave impedance data; calculate the tensor attributes of seismic data, and perform spatial smoothing processing on the tensor attributes to determine the tensor attribute threshold representing the fracture area of ​​the fault-karst body to obtain the contour of the fault-karst body; use the contour of the fault-karst body as the boundary, display the tensor attributes and the underground P-wave impedance data in the contour, and achieve the external contour characterization and internal structure characterization of the fault-karst body. This method uses P-wave impedance attributes to characterize the pore-type reservoir inside the fault-karst body, and uses tensor attributes to characterize the external morphology of the fault-karst body boundary, but cannot characterize the spatial distribution of fractures inside the fault-karst body.

[0006] The above technical background research shows that the previous methods of characterizing fault-karst bodies mainly superimpose two of the three seismic attributes of tensor, P-wave impedance and ant body, which reflect the external morphology and internal structure of fault-karst bodies, and cannot effectively characterize the external morphology and internal structure of fault-karst bodies. In addition, if these three seismic attributes are superimposed together to characterize fault-karst bodies, they can only qualitatively reflect the external morphology and internal structure of fault-karst bodies, and cannot quantitatively describe the spatial distribution of fault-karst bodies and the scale of effective reservoir space. In the internal structure of fault-karst bodies, fractures can not only communicate pores, but also are important reservoir spaces. Among the three seismic attributes of tensor, P-wave impedance and ant body, only the P-wave impedance seismic attribute has a direct relationship with porosity. The P-wave impedance obtained by conventional reservoir inversion cannot effectively reflect the spatial distribution of fractures. Therefore, there is a special need for a method that can quantitatively characterize the scale and distribution of fracture-cavity structures inside fault-karst bodies. Summary of the invention

[0007] The purpose of the present invention is to propose a method for characterizing the internal structure of carbonate fault-karst bodies by phase-controlled inversion, so as to solve the problem that the scale and distribution of the fracture-cavity structure inside the fault-karst bodies cannot be quantitatively characterized at present.

[0008] In view of this, the present invention provides a method, device, electronic equipment and medium for phase-controlled inversion to characterize the internal structure of carbonate fault-karst bodies, which at least solves the problem that there is currently no unified saturation evaluation method with strong operability and high accuracy.

[0009] In a first aspect, the present invention provides a method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion, comprising: obtaining fault-karst body seismic phases and fracture seismic phases respectively based on original seismic data; establishing a straight low-frequency model of carbonate rock; obtaining a beaded seismic phase based on the straight low-frequency model; obtaining a phase-controlled low-frequency model based on the straight low-frequency model, the fault-karst body seismic phases, the fracture seismic phases and the beaded seismic phases; obtaining a longitudinal wave impedance data body based on the phase-controlled low-frequency model; obtaining a porosity body of an effective reservoir based on the longitudinal wave impedance data body, thereby characterizing the internal structure of the carbonate fault-karst body.

[0010] Optionally, the fault-karst seismic phase is obtained according to the following steps: performing structural-guided filtering processing on the original seismic data; performing edge detection processing on the seismic data after structural-guided filtering processing; performing voxel density enhancement processing on the seismic data after edge detection processing to obtain voxel density data and seismic data after voxel density enhancement processing; and taking the seismic data after voxel density enhancement processing whose voxel density data is greater than the fault-karst body boundary threshold as the fault-karst seismic phase.

[0011] Optionally, the fracture seismic phase is obtained according to the following steps: performing structural guidance filtering processing on the original seismic data; performing AFE calculation on the original seismic data after structural guidance filtering processing to obtain an AFE attribute data body; and taking the AFE attribute data body whose AFE attribute value is less than the AFE attribute threshold of fracture development as the fracture seismic phase.

[0012] Optionally, a longitudinal wave impedance background value of the carbonate rock formation is set, and a carbonate rock straight plate low-frequency model is established based on the longitudinal wave impedance background value of the carbonate rock formation.

[0013] Optionally, obtaining the beaded seismic phase based on the straight low-frequency model includes: performing constrained sparse pulse inversion on the original seismic data based on the straight low-frequency model to obtain underground longitudinal wave impedance data; and taking the underground longitudinal wave impedance data with a longitudinal wave impedance value less than the longitudinal wave impedance threshold of the cave reservoir as the beaded seismic phase.

[0014] Optionally, obtaining a phase-controlled low-frequency model based on the straight low-frequency model, fault-karst seismic phase, fracture seismic phase and beaded seismic phase includes: embedding the fault-karst seismic phase into the straight low-frequency model; inputting a longitudinal wave impedance background value less than the carbonate rock formation into the fault-karst in the straight low-frequency model, embedding the beaded seismic phase into the fault-karst seismic phase; embedding the fracture seismic phase into the fault-karst seismic phase to obtain a phase-controlled low-frequency model.

[0015] Optionally, embedding the fracture seismic phase into the fault-karst body seismic phase includes: utilizing drilling results, inputting a longitudinal wave impedance value corresponding to the fracture seismic in the fault-karst body seismic phase after the beaded seismic phase is embedded, and embedding the fracture seismic phase into the fault-karst body seismic phase.

[0016] Optionally, obtaining a P-wave impedance data volume based on the phase-controlled low-frequency model includes: inverting the phase-controlled low-frequency model to obtain an underground P-wave impedance data volume of the phase-controlled low-frequency model; replacing a P-wave impedance background value higher than a P-wave impedance background value of a carbonate rock formation with a P-wave impedance background value of the carbonate rock formation in the underground P-wave impedance data volume of the phase-controlled low-frequency model; replacing a background value higher than a P-wave impedance background value of a fault-karst body with a P-wave impedance background value of the fault-karst body in a fault-karst body to obtain a new low-frequency model; and performing constrained sparse pulse inversion on the new low-frequency model to obtain a P-wave impedance data volume.

[0017] Optionally, based on the P-wave impedance data body, obtaining the porosity body of the effective reservoir includes: fitting the P-wave impedance data of known wells with the porosity to obtain the relationship between the P-wave impedance data and the porosity; based on the relationship between the P-wave impedance data and the porosity, converting the P-wave impedance data body into a porosity body; and based on the porosity body and the porosity threshold of the effective reservoir, obtaining the porosity body of the effective reservoir.

[0018] In a second aspect, the present invention further provides an electronic device, comprising: a memory storing executable instructions; and a processor, wherein the processor runs the executable instructions in the memory to implement the above-mentioned method of phase-controlled inversion to characterize the internal structure of carbonate fault-karst bodies.

[0019] The beneficial effects of the present invention are as follows: the method of the present invention for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion utilizes the seismic phases reflecting the contour of the fault-karst body, the "beaded" strong energy and cracks in the fault-karst body to establish a phase-controlled low-frequency model, performs post-stack inversion on the phase-controlled low-frequency model, obtains longitudinal wave impedance data, further obtains the porosity body of the effective reservoir body, intuitively characterizes the reservoir distribution, development scale and connectivity inside the fault-karst body, accurately predicts the scale of each reservoir body inside the fault-karst body, provides a reliable basis for well site deployment, improves the success rate of exploration and development drilling, and enhances the efficiency of exploration and development, and the invention is not subject to geographical restrictions and has a wide range of applications.

[0020] The present invention has other features and advantages, which will be apparent from or will be described in detail in the accompanying drawings and the following specific embodiments incorporated herein, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0022] Figure 1 A flow chart of a method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention is shown.

[0023] Figure 2 A cross-sectional view of a carbonate fault-karst body in a certain well is shown, showing a method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention.

[0024] Figure 3 A method for characterizing the internal structure of carbonate fault-karst bodies by phase-controlled inversion according to an embodiment of the present invention is shown through an AFE attribute profile of a certain well.

[0025] Figure 4 A method for describing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention is shown through a seismic diagram of a certain well and a cross-sectional diagram of the fault-karst body boundary.

[0026] Figure 5 A post-stack constrained sparse pulse inversion impedance profile of a well is shown according to a method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention.

[0027] Figure 6 A method for describing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention is shown through a beaded seismic phase section diagram of a certain well.

[0028] Figure 7 A method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention is shown, showing the fault-karst phase, fracture phase, and beaded seismic phase profiles of a certain well.

[0029] Figure 8 A phase-controlled inversion longitudinal wave impedance profile of a well is shown according to a method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention.

[0030] Fig. 9 A thickness distribution diagram of engraved traps inside a carbonate fault-karst body is shown according to a method for depicting the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention.

[0031] Fig.10A thickness distribution diagram of the traps drilled in the SHB5CX and SHB5-3 wells in a certain fault-karst body is shown, which is a method for depicting the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention.

[0032] Fig.11 A method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention is shown, using a phase-controlled inversion longitudinal wave impedance profile of the SHB5CX and SHB5-3 wells. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0034] The present invention provides a method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion, comprising: obtaining fault-karst body seismic phases and fracture seismic phases respectively based on original seismic data; establishing a carbonate straight plate low-frequency model; obtaining a string of beads seismic phase based on the straight plate low-frequency model; obtaining a phase-controlled low-frequency model based on the straight plate low-frequency model, the fault-karst body seismic phases, the fracture seismic phases and the string of beads seismic phases; obtaining a longitudinal wave impedance data body based on the phase-controlled low-frequency model; and obtaining a porosity body of an effective reservoir based on the longitudinal wave impedance data body, thereby characterizing the internal structure of the carbonate fault-karst body.

[0035] Specifically, the fault-karst seismic phase, fracture and beaded seismic phase are obtained respectively, and the fault-karst seismic phase, fracture seismic phase and beaded seismic phase are embedded in the straight low-frequency model to obtain a phase-controlled low-frequency model. Based on the phase-controlled low-frequency model, the longitudinal wave impedance data body is obtained, and the porosity body of the effective reservoir is further obtained. The porosity body of the effective reservoir characterizes the internal structure of the carbonate fault-karst body.

[0036] According to an exemplary implementation, the method of phase-controlled inversion for characterizing the internal structure of carbonate fault-karst bodies utilizes seismic phases that reflect the contours of the fault-karst bodies, the "beaded" strong energy and fractures within the fault-karst bodies, to establish a phase-controlled low-frequency model, perform post-stack inversion on the phase-controlled low-frequency model, obtain longitudinal wave impedance data, and further obtain the porosity body of the effective reservoir body, intuitively characterize the reservoir distribution, development scale and connectivity within the fault-karst bodies, and accurately predict the scale of each reservoir body within the fault-karst bodies, providing a reliable basis for well site deployment, improving the success rate of exploration and development drilling, and enhancing the benefits of exploration and development. Moreover, the invention is not subject to geographical restrictions and has a wide range of applications.

[0037] As an optional scheme, the fault-karst body seismic phase is obtained according to the following steps: performing structural-guided filtering processing on the original seismic data; performing edge detection processing on the seismic data after structural-guided filtering processing; performing voxel density enhancement processing on the seismic data after edge detection processing to obtain voxel density data and seismic data after voxel density enhancement processing; the seismic data after voxel density enhancement processing whose voxel density data is greater than the fault-karst body boundary threshold is used as the fault-karst body seismic phase.

[0038] Specifically, the original seismic data is first subjected to structural guidance filtering processing, and then the seismic data after structural guidance filtering processing is subjected to edge detection processing, and then the seismic data after edge detection processing is subjected to voxel density enhancement processing to obtain voxel density data and seismic data after voxel density enhancement processing.

[0039] The interface between carbonate rock and clastic rock is a landmark seismic reflection layer. After the seismic reflection layer is smoothed, it is close to horizontal. The value of the volume density data body corresponding to the intersection of the smoothed seismic reflection layer and the original seismic reflection layer (the value of the volume density data body is continuously distributed from small to large) is used as the threshold value of the fault-karst boundary. Data greater than this threshold value is the data contained in the fault-karst space. Therefore, this threshold value is used as the boundary value of the fault-karst body. Data greater than this threshold value belongs to the inside of the fault-karst body, and data less than this threshold value is not contained in the fault-karst body.

[0040] As an optional scheme, the fracture seismic phase is obtained according to the following steps: performing structural guidance filtering on the original seismic data; performing AFE calculation on the original seismic data after structural guidance filtering to obtain an AFE attribute data body; and taking the AFE attribute data body whose AFE attribute value is less than the AFE attribute threshold of fracture development as the fracture seismic phase.

[0041] The original seismic data is processed by structural guidance filtering, and the AFE is calculated on the seismic data after structural guidance filtering to obtain the AFE attribute data body. The AFE attribute reflects the fractures; the AFE attribute data body with an AFE attribute value less than the AFE attribute threshold of fracture development is taken as the fracture seismic phase. The AFE attribute threshold of fracture development, that is, the threshold value of AFE, is determined by using the actual drilling results.

[0042] The drilling results show that when drilling into a crack, drilling fluid leakage occurs. The geophysical characteristics of the crack can also be seen in the imaging logging. The drilling confirms that the crack develops at a certain depth. Through fine well-seismic calibration, an accurate time-depth relationship is established to determine the vertical position of the crack actually drilled on the time domain seismic profile. The calculated AFE attribute data reflecting the crack is obtained from the original seismic data, and there is no change in the vertical time, which is consistent with the original seismic data in the vertical time. The AFE attribute data value is also continuously distributed from small to large. The development position of the actual drilled crack in the time domain space is determined by well-seismic calibration. The corresponding value in the AFE data body can determine the AFE value corresponding to the crack. This value is used as the threshold value of the AFE attribute of the crack development (the AFE attribute value is distributed from small to large). If it is greater than this threshold value, no crack will develop, and if it is less than this threshold value, cracks will develop. Therefore, the AFE attribute body less than the threshold value is the crack phase of crack development.

[0043] As an optional solution, a background value of the longitudinal wave impedance of the carbonate rock formation is set, and a carbonate rock straight plate low-frequency model is established based on the background value of the longitudinal wave impedance of the carbonate rock formation.

[0044] As an optional solution, based on the straight low-frequency model, obtaining the beaded seismic phase includes: based on the straight low-frequency model, performing constrained sparse pulse inversion on the original seismic data to obtain underground P-wave impedance data; and taking the underground P-wave impedance data with a P-wave impedance value less than the P-wave impedance threshold of the cave reservoir as the beaded seismic phase.

[0045] Specifically, the straight low-frequency model is used to perform constrained sparse pulse inversion on the original seismic data to obtain underground P-wave impedance data. Given the P-wave impedance threshold value of the cave reservoir, the "beaded" seismic phase reflecting the cave reservoir is obtained.

[0046] In carbonate rock formations, a porosity greater than 5% is a good reservoir, corresponding to a cave-type reservoir. Through actual drilling data and logging data, the layer segments with a porosity greater than 5% are found out, and through well-seismic calibration, the position of the developed layer segment with a porosity greater than 5% corresponding to the seismic profile is determined. This position corresponds to a cave-type reservoir, which is manifested as a beaded seismic reflection. The longitudinal wave impedance value corresponding to the porosity of 5% is the threshold value of the beaded seismic phase, and values ​​below this threshold are all cave layer beaded seismic phases.

[0047] As an optional scheme, based on the straight low-frequency model, fault-karst seismic phase, fracture seismic phase and beaded seismic phase, obtaining a phase-controlled low-frequency model includes: embedding the fault-karst seismic phase into the straight low-frequency model; inputting a longitudinal wave impedance background value less than the carbonate rock formation into the fault-karst in the straight low-frequency model, embedding the beaded seismic phase into the fault-karst seismic phase; embedding the fracture seismic phase into the fault-karst seismic phase to obtain a phase-controlled low-frequency model.

[0048] Specifically, the fault-karst seismic phase is embedded in the straight-plate low-frequency model, the longitudinal wave impedance background value lower than the carbonate rock formation is input into the fault-karst, the characterized "beaded" seismic phase is embedded in the fault-karst, and the longitudinal wave impedance value of the fracture phase is input using the drilling results, and then embedded in the fault-karst to establish a phase-controlled low-frequency model.

[0049] As an optional solution, embedding the fracture seismic phase into the fault-karst body seismic phase includes: using the drilling results, inputting the longitudinal wave impedance value corresponding to the fracture seismic into the fault-karst body seismic phase after the beaded seismic phase is embedded, and embedding the fracture seismic phase into the fault-karst body seismic phase.

[0050] Fractures have porosity. The maximum threshold value of the impedance reflecting the fracture porosity is determined by the intersection statistical analysis of the P-wave impedance and porosity of the wells drilled in the work area. Here, the P-wave impedance threshold value of the fracture is smaller than the threshold value of the fault solution. The fracture seismic phase is a spatial distribution range. The spatial distribution of the fracture seismic phase is replaced by the P-wave impedance threshold value of the fracture to obtain the P-wave impedance low-frequency model reflecting the fracture phase.

[0051] As an optional scheme, based on the phase-controlled low-frequency model, obtaining the P-wave impedance data volume includes: inverting the phase-controlled low-frequency model to obtain the underground P-wave impedance data volume of the phase-controlled low-frequency model; in the underground P-wave impedance data volume of the phase-controlled low-frequency model, replacing the P-wave impedance background value higher than the P-wave impedance background value of the carbonate rock formation with the P-wave impedance background value of the carbonate rock formation; in the fault-karst body, replacing the background value higher than the P-wave impedance background value of the fault-karst body with the P-wave impedance background value of the fault-karst body to obtain a new low-frequency model; and performing constrained sparse pulse inversion on the new low-frequency model to obtain the P-wave impedance data volume.

[0052] Specifically, a phase-controlled low-frequency model is used to carry out constrained sparse pulse inversion to obtain underground P-wave impedance data. In the underground P-wave impedance data body, the P-wave impedance background value for carbonate rock formations that is higher than the P-wave impedance background value for carbonate rock formations is replaced, and the P-wave impedance background value in the fault-karst body that is higher than the P-wave impedance background value in the fault-karst body is replaced with the P-wave impedance background value in the fault-karst body, thus obtaining a new low-frequency model. The new low-frequency model is used to carry out a second constrained sparse pulse inversion to obtain the P-wave impedance body.

[0053] As an optional solution, based on the P-wave impedance data body, obtaining the porosity body of the effective reservoir body includes: fitting the P-wave impedance data of known wells with the porosity to obtain the relationship between the P-wave impedance data and the porosity; based on the relationship between the P-wave impedance data and the porosity, converting the P-wave impedance data body into a porosity body; based on the porosity body and the porosity threshold of the effective reservoir body, obtaining the porosity body of the effective reservoir body.

[0054] Specifically, the porosity threshold of the effective carbonate reservoir in the work area is known, and the porosity above this is the effective reservoir. The P-wave impedance threshold corresponding to the effective porosity is obtained by intersecting the effective porosity and P-wave impedance of the drilled carbonate layer, and the P-wave impedance less than this threshold is the P-wave impedance corresponding to the effective reservoir.

[0055] By fitting the P-wave impedance of the drilled well with the porosity, the P-wave impedance value corresponding to the porosity is obtained. Based on the porosity and P-wave impedance fitting curve, the porosity and P-wave impedance are linked, and the P-wave impedance body can be converted into a porosity body.

[0056] Based on the porosity threshold of the effective reservoir, the non-effective reservoir part in the porosity body is removed to obtain the porosity body of the effective reservoir.

[0057] The present invention also provides an electronic device, which includes: a memory storing executable instructions; and a processor running the executable instructions in the memory to implement the above-mentioned method of phase-controlled inversion to characterize the internal structure of carbonate fault-karst bodies.

[0058] Embodiment 1

[0059] Figure 1 A flow chart of a method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention is shown. Figure 2 A cross-sectional view of a carbonate fault-karst body in a certain well is shown, showing a method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention. Figure 3 A method for characterizing the internal structure of carbonate fault-karst bodies by phase-controlled inversion according to an embodiment of the present invention is shown through an AFE attribute profile of a certain well. Figure 4 A method for describing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention is shown through a seismic diagram of a certain well and a cross-sectional diagram of the fault-karst body boundary. Figure 5 A post-stack constrained sparse pulse inversion impedance profile of a well is shown according to a method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention. Figure 6 A method for describing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention is shown through a beaded seismic phase section diagram of a certain well. Figure 7 A method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention is shown, showing the fault-karst phase, fracture phase, and beaded seismic phase profiles of a certain well. Figure 8 A phase-controlled inversion longitudinal wave impedance profile of a well is shown according to a method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention. Fig. 9A thickness distribution diagram of engraved traps inside a carbonate fault-karst body is shown according to a method for depicting the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention. Fig.10 A thickness distribution diagram of the traps drilled in the SHB5CX and SHB5-3 wells in a certain fault-karst body is shown, which is a method for depicting the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention. Fig.11 A method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to an embodiment of the present invention is shown, using a phase-controlled inversion longitudinal wave impedance profile of the SHB5CX and SHB5-3 wells.

[0060] Combination Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 and Fig.11 As shown in FIG. 1 , the method for describing the internal structure of carbonate fault-karst bodies by phase-controlled inversion includes:

[0061] Step 1: Based on the original seismic data, the fault-karst seismic phase and the fracture seismic phase are obtained respectively;

[0062] Among them, the fault-karst seismic phase is obtained according to the following steps: performing structural-guided filtering processing on the original seismic data; performing edge detection processing on the seismic data after structural-guided filtering processing; performing voxel density enhancement processing on the seismic data after edge detection processing to obtain voxel density data and seismic data after voxel density enhancement processing; the seismic data after voxel density enhancement processing whose voxel density data is greater than the fault-karst boundary threshold is taken as the fault-karst seismic phase.

[0063] The fracture seismic phase is obtained according to the following steps: the original seismic data is subjected to structural guidance filtering processing; the original seismic data after structural guidance filtering processing is subjected to AFE calculation to obtain an AFE attribute data body; and the AFE attribute data body whose AFE attribute value is less than the AFE attribute threshold of fracture development is taken as the fracture seismic phase.

[0064] Step 2: Establish a carbonate rock straight plate low-frequency model;

[0065] The longitudinal wave impedance background value of the carbonate rock formation is set, and a carbonate rock straight plate low-frequency model is established based on the longitudinal wave impedance background value of the carbonate rock formation.

[0066] Step 3: Based on the straight plate low-frequency model, obtain the beaded seismic phase;

[0067] Among them, based on the straight low-frequency model, obtaining the beaded seismic phase includes: based on the straight low-frequency model, constrained sparse pulse inversion is performed on the original seismic data to obtain underground longitudinal wave impedance data; underground longitudinal wave impedance data with a longitudinal wave impedance value less than the longitudinal wave impedance threshold of the cave reservoir is used as the beaded seismic phase.

[0068] Step 4: Based on the straight plate low-frequency model, fault-karst seismic phase, fracture seismic phase and beaded seismic phase, a phase-controlled low-frequency model is obtained;

[0069] Among them, based on the straight low-frequency model, fault-karst seismic phase, fracture seismic phase and beaded seismic phase, the phase-controlled low-frequency model is obtained, including: embedding the fault-karst seismic phase into the straight low-frequency model; inputting a longitudinal wave impedance background value less than the carbonate rock formation into the fault-karst in the straight low-frequency model, embedding the beaded seismic phase into the fault-karst seismic phase; embedding the fracture seismic phase into the fault-karst seismic phase to obtain the phase-controlled low-frequency model.

[0070] Among them, embedding the fracture seismic phase into the fault-karst body seismic phase includes: using the drilling results, inputting the longitudinal wave impedance value corresponding to the fracture seismic in the fault-karst body seismic phase after the beaded seismic phase is embedded, and embedding the fracture seismic phase into the fault-karst body seismic phase.

[0071] Step 5: Based on the phase-controlled low-frequency model, obtain the longitudinal wave impedance data volume;

[0072] Among them, based on the phase-controlled low-frequency model, obtaining the longitudinal wave impedance data volume includes: inverting the phase-controlled low-frequency model to obtain the underground longitudinal wave impedance data volume of the phase-controlled low-frequency model; in the underground longitudinal wave impedance data volume of the phase-controlled low-frequency model, replacing the longitudinal wave impedance background value higher than the longitudinal wave impedance background value of the carbonate rock formation with the longitudinal wave impedance background value of the carbonate rock formation; in the fault-karst body, replacing the background value higher than the longitudinal wave impedance background value of the fault-karst body with the longitudinal wave impedance background value of the fault-karst body to obtain a new low-frequency model; and performing constrained sparse pulse inversion on the new low-frequency model to obtain the longitudinal wave impedance data volume.

[0073] Step 6: Based on the P-wave impedance data volume, obtain the porosity volume of the effective reservoir to characterize the internal structure of the carbonate fault-karst body.

[0074] Among them, based on the P-wave impedance data body, obtaining the porosity body of the effective reservoir body includes: fitting the P-wave impedance data of known drilling wells with the porosity to obtain the relationship between the P-wave impedance data and the porosity; based on the relationship between the P-wave impedance data and the porosity, converting the P-wave impedance data body into a porosity body; based on the porosity body and the porosity threshold of the effective reservoir body, obtaining the porosity body of the effective reservoir body.

[0075] exist Figure 2 In the figure, the volume element density attribute value near the intersection of the seismic reflection layer and the smoothed layer is the threshold for describing the fault-karst boundary. Figure 3 In , the seismic phase reflecting the fracture is calculated by AFE. Figure 8 In the figure, the shape of the fault-karst body and the vertical and horizontal connectivity of the fractures and cavities inside the fault-karst body are intuitively reflected. The brighter the color, the lower the impedance value, reflecting the better the reservoir properties.

[0076] The present invention was applied to the block of fault-karst body that is currently of great concern in the Tarim Basin. A well was side-drilled to 7945.09 m and lost return. The emptying footage was 2.92 m and the lost mud was 482.01 m. 3 The emptying section corresponds to the low longitudinal wave impedance area predicted by this method in the figure, as shown in Figure 8 As shown in the figure, the actual drilling results are consistent with the predicted results. Fig. 9 In the blue circle, the traps drilled by wells SHB5CX and SHB5-3 are connected together. In fact, the traps drilled by wells SHB5CX and SHB5-3 are separated in space. Fig.10 The results of using this method to predict the well profiles of the two wells in the blue circle show that they are also not connected. Fig.11 As shown, the actual production capacity of the two wells in the later period indicates that the two wells are not connected, and the prediction results are consistent with the actual production situation.

[0077] Embodiment 2

[0078] The present disclosure provides an electronic device, which includes: a memory storing executable instructions; a processor running the executable instructions in the memory to implement the above-mentioned method of phase-controlled inversion to characterize the internal structure of carbonate fault-karst bodies.

[0079] An electronic device according to an embodiment of the present disclosure includes a memory and a processor.

[0080] The memory is used to store non-temporary computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.

[0081] The processor may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In one embodiment of the present disclosure, the processor is used to run the computer-readable instructions stored in the memory.

[0082] Those skilled in the art should be able to understand that in order to solve the technical problem of how to obtain a good user experience, the present embodiment may also include well-known structures such as a communication bus and an interface, and these well-known structures should also be included in the protection scope of the present disclosure.

[0083] For detailed description of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0084] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for describing the internal structure of carbonate fault-karst bodies by phase-controlled inversion, characterized in that: include: Based on the original seismic data, the fault-karst seismic phase and the fracture seismic phase are obtained respectively; Establish a low-frequency model of carbonate rock straight plate; Based on the straight plate low-frequency model, obtaining the beaded seismic phase; Based on the straight plate low-frequency model, fault-karst seismic phase, fracture seismic phase and beaded seismic phase, a phase-controlled low-frequency model is obtained; Based on the phase-controlled low-frequency model, a longitudinal wave impedance data volume is obtained; Based on the P-wave impedance data body, the porosity body of the effective reservoir is obtained, thereby describing the internal structure of the carbonate fault-karst body; Wherein, a longitudinal wave impedance background value of the carbonate rock formation is set, and a carbonate rock straight plate low-frequency model is established based on the longitudinal wave impedance background value of the carbonate rock formation; Wherein, obtaining a phase-controlled low-frequency model based on the straight plate low-frequency model, fault-karst seismic phase, fracture seismic phase and beaded seismic phase includes: embedding the fault-karst seismic phase into the straight plate low-frequency model; Inputting a longitudinal wave impedance background value less than that of the carbonate rock formation into the fault-karst body in the straight low-frequency model, so as to embed the beaded seismic phase into the fault-karst body seismic phase; Embedding the fracture seismic phase into the fault-karst body seismic phase to obtain a phase-controlled low-frequency model; Wherein, obtaining the longitudinal wave impedance data body based on the phase-controlled low-frequency model includes: Inverting the phase-controlled low-frequency model to obtain an underground longitudinal wave impedance data volume of the phase-controlled low-frequency model; In the underground P-wave impedance data volume of the phase-controlled low-frequency model, a background value higher than a P-wave impedance background value of a carbonate rock formation is replaced with the P-wave impedance background value of the carbonate rock formation; In the fault-solid body, a background value higher than the background value of the longitudinal wave impedance of the fault-solid body is replaced by the background value of the longitudinal wave impedance of the fault-solid body to obtain a new low-frequency model; The new low-frequency model is subjected to constrained sparse pulse inversion to obtain the longitudinal wave impedance data volume.

2. The method for characterizing the internal structure of carbonate fault-karst bodies by phase-controlled inversion according to claim 1, characterized in that: Obtain the fault-karst seismic facies according to the following steps: Performing structural guidance filtering on the original seismic data; Perform edge detection on the seismic data after structural guidance filtering; Performing voxel density enhancement processing on the seismic data after edge detection processing to obtain voxel density data and seismic data after voxel density enhancement processing; The seismic data after volume element density enhancement processing whose volume element density data is greater than the fault-karst body boundary threshold is regarded as the fault-karst body seismic phase.

3. The method for characterizing the internal structure of carbonate fault-karst bodies by phase-controlled inversion according to claim 2, characterized in that: Obtain the fracture seismic phase according to the following steps: Performing structural guidance filtering on the original seismic data; Perform AFE calculation on the original seismic data after structural guidance filtering to obtain AFE attribute data volume; The AFE attribute data volume whose AFE attribute value is less than the AFE attribute threshold of fracture development is taken as the fracture seismic phase.

4. The method for characterizing the internal structure of carbonate fault-karst bodies by phase-controlled inversion according to claim 1, characterized in that: The step of obtaining the beaded seismic phase based on the straight plate low-frequency model comprises: Based on the straight plate low-frequency model, constrained sparse pulse inversion is performed on the original seismic data to obtain underground longitudinal wave impedance data; The underground P-wave impedance data with P-wave impedance values ​​less than the P-wave impedance threshold of the cave reservoir are regarded as the beaded seismic phase.

5. The method for characterizing the internal structure of carbonate fault-karst bodies by phase-controlled inversion according to claim 1, characterized in that: The embedding of the fracture seismic phase into the fault-karst body seismic phase comprises: By using the drilling results, the longitudinal wave impedance value corresponding to the fracture seismic is input into the fault-karst body seismic phase after the beaded seismic phase is embedded, and the fracture seismic phase is embedded into the fault-karst body seismic phase.

6. The method for characterizing the internal structure of carbonate fault-karst bodies by phase-controlled inversion according to claim 1, characterized in that: Based on the P-wave impedance data body, obtaining the porosity body of the effective reservoir body includes: Fitting the known well P-wave impedance data with the porosity to obtain the relationship between the P-wave impedance data and the porosity; Based on the relationship between longitudinal wave impedance data and porosity, the longitudinal wave impedance data volume is converted into a porosity volume: Based on the porosity volume and the porosity threshold of the effective reservoir, the porosity volume of the effective reservoir is obtained.

7. An electronic device, characterized in that: The electronic device comprises: A memory storing executable instructions; A processor, wherein the processor runs the executable instructions in the memory to implement the method for characterizing the internal structure of a carbonate fault-karst body by phase-controlled inversion according to any one of claims 1 to 6.

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