A method for characterizing fractured and vuggy reservoirs

Abstract

The application discloses a method for describing a fracture-controlled fracture-vug type reservoir body, and comprises the following steps: obtaining three-dimensional seismic reflection amplitude data D, and calculating three-dimensional relative impedance data; calculating absolute impedance data I p ; calculating impedance background trend I p_bg of the absolute impedance data I p and amplitude background trend D bg of the three-dimensional seismic reflection amplitude data D respectively; calculating the difference between the absolute impedance data I p and the impedance background trend I p_bg , and calculating the difference between the three-dimensional seismic reflection amplitude data D and the amplitude background trend D bg ; calculating a vug response based on the background trend suppressed impedance data I p_diff , and calculating a fracture-vug zone response based on the background trend suppressed seismic amplitude data D diff ; the application is started from inversion, a constraint term is introduced, the spatial heterogeneity of the inversion result can be effectively improved, the application provides an optimization method for background trend suppression and abnormal response enhancement, and the identification precision of the dissolution cavity and the fracture-vug zone is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of seismic exploration, and more particularly relates to a method for depicting a fault-controlled fracture-vug type reservoir, an electronic device and a medium. BACKGROUND

[0002] At present, fault-controlled fracture-vug type oil and gas reservoirs are not common in the world, but such reservoirs store a large amount of oil and gas resources. Compared with foreign countries, fault-controlled fracture-vug type oil and gas reservoirs in China have large burial depth, complex late-stage reconstruction, strong reservoir heterogeneity and great difficulty in exploration and development. The "dissolution cavity" and "fracture-vug zone" are important reservoir spaces of such reservoirs. For the identification of such reservoir spaces, the current methods mainly include three kinds: the first kind is to use seismic reflection amplitude and frequency division data seismic attributes to depict the dissolution zone; the second kind is to use the parameters obtained by inversion and the threshold value of sensitive parameters to carve the solution cavity based on sparse pulse or geostatistical inversion method; and the third kind is to use the fault-dissolution body contour attribute to constrain the reconstruction of the low-frequency model used in the inversion, and then to depict the solution cavity based on the low-resistance body anomaly obtained by inversion.

[0003] In the existing method, the first kind of attribute calculation method is simple and convenient, but is affected by the wavelet and cannot accurately reflect the true development position of the underground dissolution cavity. In the second and third kinds of methods, although the impedance inversion involved can reduce the wavelet side lobe effect, restore the development position of the dissolution cavity core and thin the dissolution cavity volume, in a fault-controlled oil and gas reservoir with weak dissolution, the low-resistance solution cavity anomaly response obtained by inversion is easily submerged by the background reflection. At present, most of the researches focus on the prediction of the dissolution cavity and the fault-dissolution body contour zone, and few researches involve the highlight identification of the "fracture-vug zone".

[0004] Therefore, it is expected to invent a method for depicting a fault-controlled fracture-vug type reservoir, which can solve the problem of low precision in depicting the fracture-vug zone in the prior art. SUMMARY

[0005] The purpose of the present application is to provide a method for depicting a fault-controlled fracture-vug type reservoir to solve the problem of low precision in depicting the fracture-vug zone in the prior art.

[0006] In order to achieve the above purpose, the present application provides a method for depicting a fault-controlled fracture-vug type reservoir, comprising:

[0007] Step 1: obtaining three-dimensional seismic reflection amplitude data D, and obtaining three-dimensional relative impedance data based on the three-dimensional seismic reflection amplitude data D;

[0008] Step 2: obtaining a relative impedance pseudo-well curve at a well point based on the three-dimensional relative impedance data, and obtaining a conversion relationship formula between P-wave impedance and relative impedance based on the relative impedance pseudo-well curve and middle-low frequency data in a P-wave impedance logging curve, and then obtaining absolute impedance data I p ;

[0009] Step 3: based on the absolute impedance data I p and the three-dimensional seismic reflection amplitude data D, selecting a three-dimensional sliding window V under the control of a three-dimensional trend of a structural horizon, and calculating impedance background trends I p of the absolute impedance data I p_bg and amplitude background trends D bg of the three-dimensional seismic reflection amplitude data D according to the selected three-dimensional sliding window V;

[0010] Step 4: calculating a difference between the absolute impedance data I p and the impedance background trends I p_bg to obtain background trend suppressed impedance data I p_diff , and calculating a difference between the three-dimensional seismic reflection amplitude data D and the amplitude background trends D bg to obtain background trend suppressed seismic amplitude data D diff ;

[0011] Step 5: based on the background trend suppressed impedance data I p_diff , a cave response is calculated, and based on the background trend suppressed seismic amplitude data D diff , a fracture-cave zone response is calculated.

[0012] Optionally, the step 1 comprises:

[0013] Step 11: obtaining three-dimensional seismic reflection amplitude data D and logging velocity data or seismic interpretation velocity data;

[0014] Step 12: calibrating a time domain and a depth domain by using the logging velocity data or the seismic interpretation velocity data to obtain a time-depth calibration result;

[0015] Step 13: estimating a wavelet W corresponding to the target layer based on the time-depth calibration result;

[0016] Step 14: obtaining relative impedance based on the three-dimensional seismic reflection amplitude data D and the wavelet W, and then obtaining the three-dimensional relative impedance data.

[0017] Optionally, the step 2 comprises:

[0018] Step 21: obtaining a relative impedance pseudo well curve at a well point based on the three-dimensional relative impedance data, and obtaining a conversion relationship formula between the P-wave impedance and the relative impedance based on the relative impedance pseudo well curve and a mid-low frequency curve in the P-wave impedance logging, and then obtaining a low frequency trend model I p_trend ;

[0019] Step 22: constructing a low frequency constraint expression Trend according to the low frequency trend model I p_trend .

[0020] Step 23: constructing an inversion objective function F(R p ) based on the low frequency constraint expression Trend;

[0021] Step 24: substituting a wavelet matrix W corresponding to the target layer into the inversion objective function F(R p ), to obtain a P-wave impedance reflectivity R p .

[0022] Step 25: substituting the P-wave impedance reflectivity R p into the following formula, to obtain absolute impedance data I p .

[0023]

[0024] Wherein, t is a sampling time, I p1 is an absolute value of the P-wave impedance at a starting time in the low frequency trend model, and R p (t) is the P-wave impedance reflectivity at the sampling time t.

[0025] Optionally, the step 21 comprises:

[0026] obtaining a relative impedance pseudo well curve at a well point based on the three-dimensional relative impedance data;

[0027] obtaining original P-wave impedance data of the well logging;

[0028] sequentially performing low-pass filtering and resampling processing on the original P-wave impedance data of the well logging, to obtain a measured P-wave impedance logging curve at the well point;

[0029] crossplotting the measured P-wave impedance logging curve and the relative impedance pseudo well curve, to obtain a conversion relationship formula between the P-wave impedance and the relative impedance;

[0030] based on the conversion relationship formula, converting the three-dimensional relative impedance data into the low frequency trend model I p_trend .

[0031] Optionally, the low frequency constraint expression Trend is

[0032] Trend=ω Ip ||L Ip MR p -I p_trend ||2,

[0033] Where, ω Ip To adjust the hyperparameter of the weights of the low-frequency constraint term, L Ip Let M be the low-pass filter matrix, M be the integral matrix, and R be the integral matrix. p The longitudinal wave impedance reflectivity;

[0034] The inversion objective function F(R) p )for

[0035]

[0036] Where W is the wavelet matrix corresponding to the target layer. Here, α is the sparse constraint term, and α is the weight adjustment parameter of the sparse constraint term.

[0037] Optionally, step 3 includes:

[0038] Based on the absolute impedance data I p The three-dimensional seismic reflection amplitude data D, along the stratigraphic trend, under the control of the development trend of the tectonic stratigraphic layer, selects the three-dimensional sliding window V, wherein the three-dimensional sliding window V includes i sampling points;

[0039] Following the aforementioned layered structural trend, taking any sampling point as the center point, the i sampling points within the three-dimensional sliding window V are rearranged such that V1 < V2 < V3 < ... < V i The median (V1+V) of the samples within the three-dimensional sliding window V is obtained. i ) / 2 and take the median as the center of the three-dimensional sliding window V, where V i This refers to the i-th sampling point within window V;

[0040] Based on the median of the samples within the three-dimensional sliding window V, the absolute impedance data I are calculated respectively. p Impedance background trend I p_bg and the amplitude background trend D of the three-dimensional seismic reflection amplitude data D bg .

[0041] Optionally,

[0042] I p_diff =I p -I p_bg , among which, I p I represents the absolute impedance data. p_bg Indicating the background impedance trend, Ip_diff representing the impedance data after suppressing the background trend;

[0043] D diff = D - D bg ,

[0044] wherein D represents the three-dimensional seismic reflection amplitude data, D bg represents the amplitude background trend.

[0045] Optionally, the step 5 comprises:

[0046] substituting the impedance data I p_diff after suppressing the background trend into an enhanced calculation formula of the dissolution cave response to obtain a dissolution cave response IPE, the enhanced calculation formula of the dissolution cave response being

[0047]

[0048] wherein e is a natural exponent, β is a scaling factor and the value of β is greater than 1;

[0049] performing phase conversion on the seismic amplitude data D diff after suppressing the background trend to obtain a phase-corrected fracture-cave zone abnormal amplitude D diff_h ;

[0050] based on the phase-corrected fracture-cave zone abnormal amplitude D diff_h , obtaining a fracture-cave zone response ENV through an energy envelope calculation formula, the energy envelope calculation formula being

[0051]

[0052] wherein t is a sampling time, D diff_hf (t) is a real part of D diff_h obtained through Hilbert transform, D diff_hg (t) is an imaginary part of D diff_h obtained through Hilbert transform.

[0053] An electronic device, comprising:

[0054] a memory storing executable instructions;

[0055] a processor running the executable instructions in the memory to implement the method for delineating fault-controlled fracture-cave reservoirs.

[0056] A computer readable storage medium storing a computer program, the computer program being executed by a processor to implement the method for delineating fault-controlled fracture-cave reservoirs.

[0057] The beneficial effects of the present application are that:

[0058] The present application firstly acquires three-dimensional seismic reflection amplitude data and calculates three-dimensional relative impedance data, then acquires a conversion relationship formula between a middle-low frequency P-wave impedance logging curve and a relative impedance pseudo well curve, and carries out P-wave impedance inversion, and then obtains absolute P-wave impedance data, again based on the P-wave absolute impedance data obtained by inversion and the three-dimensional seismic reflection amplitude data, corresponding background trend values are calculated respectively, background trend interference suppression processing is carried out, and finally on the basis of background trend suppression, dissolution cavity and fracture-cave zone response enhancement optimization processing is carried out to obtain dissolution cavity response and fracture-cave zone response; the present application starts from inversion, combines good logging information and seismic information, and introduces a constraint term under the condition that the true reflection characteristics of the underground are not damaged, the introduction of the constraint term can effectively improve the spatial heterogeneity of the inversion result, at the same time, the present application provides a background trend suppression and abnormal response enhancement optimization method, so as to improve the identification precision of dissolution cavities and fracture-cave zones, and again, when a reservoir zone is three-dimensionally depicted in an actual research area, the two different facies zones of dissolution cavities and fracture-cave zones are comprehensively constrained, the multi-solution problem of reservoir zone prediction can be effectively reduced, and the ability of seismic data to depict fault-controlled oil and gas reservoirs is further improved.

[0059] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0060] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the figures, and wherein:

[0061] Figure 1 A flow chart of a method for depicting a fault-controlled fracture-cave type reservoir according to one embodiment of the present application is shown.

[0062] Figure 2 A measured data constructed dissolution cavity numerical model example profile of a method for depicting a fault-controlled fracture-cave type reservoir according to one embodiment of the present application is shown.

[0063] Figure 3 A seismic forward synthetic record obtained by a measured data constructed dissolution cavity numerical model of a method for depicting a fault-controlled fracture-cave type reservoir according to an embodiment of the present application is shown.

[0064] Figure 4 A P-wave impedance profile obtained by inversion based on a forward synthetic record of a method for depicting a fault-controlled fracture-cave type reservoir according to one embodiment provided by the present specification is shown.

[0065] Figure 5A calculated P-wave impedance trend profile of a delineation method of a fractured-caved-vuggy reservoir according to one embodiment provided in the specification is shown;

[0066] Figure 6 An impedance profile after background trend suppression of a delineation method of a fractured-caved-vuggy reservoir according to one embodiment provided in the specification is shown;

[0067] Figure 7 A result of a dissolution cavity carving after dissolution cavity response enhancement of a delineation method of a fractured-caved-vuggy reservoir according to one embodiment provided in the specification is shown;

[0068] Figure 8 A fractured-caved-vuggy zone numerical model constructed based on measured data of a delineation method of a fractured-caved-vuggy reservoir according to another embodiment provided in the specification is shown;

[0069] Figure 9 A seismic forward synthetic record calculated based on a fractured-caved-vuggy zone numerical model of a delineation method of a fractured-caved-vuggy reservoir according to another embodiment provided in the specification is shown;

[0070] Figure 10 An energy envelope obtained based on seismic data of a delineation method of a fractured-caved-vuggy reservoir according to another embodiment provided in the specification is shown;

[0071] Figure 11 An energy envelope based on a fractured-caved-vuggy zone response according to the present application of a delineation method of a fractured-caved-vuggy reservoir according to another embodiment provided in the specification is shown;

[0072] Figure 12 A comparison of results obtained by post-stack inversion based on measured seismic data (a) and a dissolution cavity delineation method according to the present application (b) of a delineation method of a fractured-caved-vuggy reservoir according to another embodiment provided in the specification is shown;

[0073] Figure 13 A comparison of results obtained by energy envelope calculation based on measured seismic data (a) and a fractured-caved-vuggy zone carving method according to the present application (b) of a delineation method of a fractured-caved-vuggy reservoir according to another embodiment provided in the specification is shown;

[0074] Figure 14 A comparison of results of dissolution cavity and fractured-caved-vuggy zone identification based on measured seismic data (a) of a delineation method of a fractured-caved-vuggy reservoir according to another embodiment provided in the specification is shown. DETAILED DESCRIPTION

[0075] Preferred embodiments of the present application will be described in greater detail below. While the preferred embodiments of the present application will be described, it is understood that the present application can be practiced with various modifications to these preferred embodiments and that the present application should not be limited to the embodiments set forth herein. Rather, these preferred embodiments are included so that this present application will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0076] According to the method for characterizing a fractured-vuggy reservoir according to the present application, the method comprises:

[0077] Step 1: obtaining three-dimensional seismic reflection amplitude data D, and obtaining three-dimensional relative impedance data based on the three-dimensional seismic reflection amplitude data D;

[0078] Step 2: obtaining a relative impedance pseudo-well curve at a well point based on the three-dimensional relative impedance data, and obtaining a conversion relationship formula between P-wave impedance and relative impedance based on the relative impedance pseudo-well curve and medium-low frequency data in a P-wave impedance logging curve, and further obtaining absolute impedance data I p ;

[0079] Step 3: based on the absolute impedance data I p and the three-dimensional seismic reflection amplitude data D, selecting a three-dimensional sliding window V under the control of a three-dimensional trend in a structural horizon, and calculating an impedance background trend I p of the absolute impedance data I p_bg and an amplitude background trend D bg of the three-dimensional seismic reflection amplitude data D according to the selected three-dimensional sliding window V;

[0080] Step 4: calculating a difference between the absolute impedance data I p and the impedance background trend I p_bg to obtain background-trend-suppressed impedance data I p_diff , and calculating a difference between the three-dimensional seismic reflection amplitude data D and the amplitude background trend D bg to obtain background-trend-suppressed seismic amplitude data D diff ;

[0081] Step 5: calculating a vug response based on the background-trend-suppressed impedance data I p_diff , and calculating a fractured-vuggy zone response based on the background-trend-suppressed seismic amplitude data D diff .

[0082] Specifically, the present application firstly acquires three-dimensional seismic reflection amplitude data and calculates three-dimensional relative impedance data, then acquires a conversion relationship formula between a middle-low frequency P-wave impedance logging curve and a relative impedance pseudo well curve, and carries out P-wave impedance inversion, and then obtains absolute P-wave impedance data, again based on the P-wave absolute impedance data obtained by inversion and the three-dimensional seismic reflection amplitude data, corresponding background trend values are calculated respectively, background trend interference suppression processing is carried out, and finally, on the basis of background trend suppression, dissolution hole and fracture-vug belt response enhancement optimization processing is carried out, to obtain dissolution hole response and fracture-vug belt response; the present application starts from inversion, combines good logging information and seismic information, under the condition of keeping the true reflection characteristics of the underground from being damaged, a constraint term is introduced, the introduction of the constraint term can effectively improve the spatial heterogeneity of the inversion result, at the same time, the present application provides an optimization method for background trend suppression and abnormal response enhancement, so as to improve the identification precision of dissolution holes and fracture-vug belts, and again, when a reservoir belt is three-dimensionally depicted in an actual research area, the two different facies belts of dissolution holes and fracture-vug belts are combined to constrain together, which can effectively reduce the multi-solution of reservoir belt prediction, and further improve the depiction ability of seismic data for fault-controlled oil and gas reservoirs.

[0083] In one example, step 1 comprises:

[0084] Step 11: acquiring three-dimensional seismic reflection amplitude data D and logging velocity data or seismic interpreted velocity data;

[0085] Step 12: calibrating the time domain and the depth domain by using the logging velocity data or the seismic interpreted velocity data, to obtain a time-depth calibration result;

[0086] Step 13: estimating a wavelet W corresponding to the target layer based on the time-depth calibration result;

[0087] Step 14: calculating relative impedance based on the three-dimensional seismic reflection amplitude data D and the wavelet W, and then obtaining three-dimensional relative impedance data.

[0088] In one example, step 2 comprises:

[0089] Step 21: acquiring a relative impedance pseudo well curve at a well point based on the three-dimensional relative impedance data, and obtaining a conversion relationship formula between P-wave impedance and relative impedance based on the relative impedance pseudo well curve and a middle-low frequency curve in the P-wave impedance logging, and then obtaining a low frequency trend model I p_trend ;

[0090] Step 22: constructing a low frequency constraint expression Trend according to the low frequency trend model I p_trend ;

[0091] Step 23: constructing an inversion objective function F(R p);

[0092] Step 24: substituting the wave matrix W corresponding to the target layer into the inversion objective function F(R p ) to obtain the P-wave impedance reflectivity R p ;

[0093] Step 25: substituting the P-wave impedance reflectivity R p into the following formula to obtain the absolute impedance data I p ,

[0094]

[0095] where t is the sampling time, I p1 is the P-wave impedance absolute value at the starting time in the low-frequency trend model, and R p (t) is the P-wave impedance reflectivity at the sampling time t.

[0096] Specifically, the application constructs a low-frequency constraint expression through a low-frequency trend model, and constructs an inversion objective function based on the low-frequency constraint expression. The introduction of the low-frequency constraint term effectively improves the spatial heterogeneity of the inversion result, thereby improving the ability of the inversion result to depict the lateral heterogeneity of the reservoir.

[0097] In one example, step 21 includes:

[0098] obtaining a relative impedance pseudo-well curve at the well point based on the three-dimensional relative impedance data;

[0099] obtaining the original P-wave impedance data of the well logging;

[0100] sequentially performing low-pass filtering and resampling processing on the original P-wave impedance data of the well logging to obtain a measured P-wave impedance logging curve at the well point;

[0101] intersecting the measured P-wave impedance logging curve and the relative impedance pseudo-well curve to obtain a conversion relationship formula between the P-wave impedance and the relative impedance;

[0102] based on the conversion relationship formula, converting the three-dimensional relative impedance data into a low-frequency trend model I p_trend .

[0103] Specifically, the original P-wave impedance data of the well logging is sequentially subjected to low-pass filtering and resampling processing. In actual operation, the highest cutoff value of the frequency band of the filtering is referenced to the frequency band range of the seismic data, and the resampling parameters are consistent with the seismic data.

[0104] In one example, the low-frequency constraint expression Trend is

[0105] Trend=ω Ip ||L IpMR p -I p_trend ||2,

[0106] Where, ω Ip To adjust the hyperparameter of the weights of the low-frequency constraint term, L Ip Let M be the low-pass filter matrix, M be the integral matrix, and R be the integral matrix. p The longitudinal wave impedance reflectivity;

[0107] Inversion objective function F(R) p )for

[0108]

[0109] Where W is the wavelet matrix corresponding to the target layer. Here, α represents the sparse constraint term, and α is the weight adjustment parameter for the sparse constraint term.

[0110] In one example, step 3 includes:

[0111] Step 3 includes:

[0112] Based on absolute impedance data I p Based on the three-dimensional seismic reflection amplitude data D, and under the control of the development trend of the tectonic strata, a three-dimensional sliding window V is selected, wherein the three-dimensional sliding window V includes i sampling points;

[0113] Following the stratigraphic trend, taking any sampling point as the center, rearrange the i sampling points within the three-dimensional sliding window V such that V1 < V2 < V3 < ... < V i The median (V1+V) of the samples within the three-dimensional sliding window V is obtained. i ) / 2 and use the median as the center of the three-dimensional sliding window V, where V i This refers to the i-th sampling point within window V;

[0114] Based on the median of the samples within the three-dimensional sliding window V, the absolute impedance data I are calculated respectively. p Impedance background trend I p_bg The amplitude background trend of the three-dimensional seismic reflection amplitude data D bg .

[0115] Specifically, based on absolute impedance data I p Based on the 3D seismic reflection amplitude data D, and under the control of the development trend of the tectonic horizon, a 3D sliding window V is selected, containing i sampling points. Following the tectonic trend, with any sampling point as the center point O, an appropriate window step size is selected to obtain the 3D sliding window V. The i sampling points within the 3D sliding window V are rearranged such that V1 < V2 < V3 < ... < V i, the median of the samples within the three-dimensional sliding window V (V1+V i ) / 2 is obtained and the median is replaced by the center value O of the three-dimensional sliding window V, where V i is the i-th sample point within the window V; the center point of the three-dimensional sliding window V is slid over each sample point in the study area, and the obtained three-dimensional data is the impedance background trend I p of the absolute impedance data I p_bg and the amplitude background trend D bg of the three-dimensional seismic reflection amplitude data D.

[0116] Further, in actual operation, the window length is preferably an odd number.

[0117] In one example,

[0118] I p_diff = I p -I p_bg ,

[0119] where I p represents the absolute impedance data, I p_bg represents the impedance background trend, and I p_diff represents the impedance data after background trend suppression;

[0120] D diff = D-D bg ,

[0121] where D represents the three-dimensional seismic reflection amplitude data, and D bg represents the amplitude background trend.

[0122] Specifically, I p_diff represents the impedance anomaly after removing the background interference, and a low value indicates a dissolution cave anomaly response; D diff represents the amplitude anomaly after removing the background interference, and an abnormal value indicates the range of the fracture-cave zone.

[0123] In one example, step 5 includes:

[0124] The impedance data I p_diff after background trend suppression is substituted into the enhancement calculation formula of the dissolution cave response to obtain the dissolution cave response IPE, and the enhancement calculation formula of the dissolution cave response is

[0125]

[0126] where e is the natural exponential, β is the scaling factor and the value of β is greater than 1;

[0127] The seismic amplitude data D diff after background trend suppression is subjected to phase conversion to obtain the phase-corrected fracture-cave zone anomaly amplitude D diff_h ;

[0128] Based on the homing after the fracture-cave belt abnormal amplitude D diff_h , the fracture-cave belt response ENV is obtained by the energy envelope calculation formula, and the energy envelope calculation formula is

[0129]

[0130] Wherein, t is the sampling time, D diff_hf (t) is D diff_h The real part obtained by Hilbert transform, D diff_hg (t) is D diff_h The imaginary part obtained by Hilbert transform.

[0131] Specifically, in actual operation, the value of β can be adjusted according to the actual test situation of different research areas; The greater the IPE value, the more developed the dissolution cave is; The greater the ENV value, the more developed the fracture-cave belt is.

[0132] An electronic device, the electronic device comprising:

[0133] A memory, the memory has executable instructions;

[0134] A processor, the processor runs the executable instructions in the memory to realize the described fracture-cave type reservoir characterization method.

[0135] A computer readable storage medium, the computer readable storage medium stores a computer program, the computer program is executed by the processor to realize the described fracture-cave type reservoir characterization method.

[0136] Embodiment 1

[0137] As Figure 1 shown, a fracture-cave type reservoir characterization method, comprising:

[0138] Step 1: obtain three-dimensional seismic reflection amplitude data D, and obtain three-dimensional relative impedance data based on three-dimensional seismic reflection amplitude data D;

[0139] Step 2: based on the three-dimensional relative impedance data, the relative impedance pseudo well curve at the well point is obtained, and based on the relative impedance pseudo well curve and the middle-low frequency data in the compressional wave impedance logging curve, the conversion relationship formula between the compressional wave impedance and the relative impedance is obtained, and then the absolute impedance data I p is calculated;

[0140] Step 3: based on the absolute impedance data I p and three-dimensional seismic reflection amplitude data D, under the control of three-dimensional trend in the structural horizon, three-dimensional sliding window V is selected, and according to the selected three-dimensional sliding window V, the absolute impedance data I pImpedance background trend I p_bg Amplitude background trend D of the three-dimensional seismic reflection amplitude data D bg ;

[0141] Step 4: Calculate the difference between the absolute impedance data I p and the impedance background trend I p_bg , to obtain the background trend suppressed impedance data I p_diff , and calculate the difference between the three-dimensional seismic reflection amplitude data D and the amplitude background trend D bg , to obtain the background trend suppressed seismic amplitude data D diff ;

[0142] Step 5: Based on the background trend suppressed impedance data I p_diff , the cave response is calculated, and based on the background trend suppressed seismic amplitude data D diff , the fracture-cave zone response is calculated.

[0143] As shown in Figure 2 , the numerical model of the dissolution cave constructed based on the measured data is constrained by the three-dimensional structural interpretation model framework of the actual research area, and the background stratum is constructed by using the logging data interpolation, and then different sizes and shapes of dissolution caves are added, as shown by the arrow in Figure 2 . Due to the dissolution effect, the impedance inside the dissolution cave is relatively low compared with the surrounding rock, so a relatively small impedance value is selected when assigning parameters to the inside of the dissolution cave. Based on the model, the reflection coefficient is calculated, and then convolved with the Ricker wavelet with a main frequency of 25Hz to obtain the seismic synthetic record, as shown in Figure 3 . Due to the influence of the shallow strong reflection axis, it can be seen that the top dissolution cave reflection is easily submerged in the background strong reflection, as shown in Figure 3 by the dashed ellipse.

[0144] As shown in Figure 4 , compared with the seismic reflection amplitude, the impedance inversion result improves the resolution of the dissolution cave to some extent, but is still affected by the background stratum, so that the boundary of the dissolution cave cannot be accurately carved, for example Figure 4 , the dissolution cave reflection inside the dashed ellipse is affected by the upper low-impedance strip, as shown by the arrow in Figure 4 , and its contour cannot be clearly carved. The dissolution cave response inside the solid ellipse in the figure is weaker than the shallow low-impedance strip, and the effective information is easily excluded when using the threshold value for dissolution carving in the subsequent process, resulting in incomplete dissolution body identification. These problems will make it difficult to use a single threshold value for three-dimensional space carving of the dissolution cave in subsequent interpretation, resulting in dissolution interpretation errors.

[0145] As shown in Figure 5 , by comparing Figure 4 and Figure 5As can be seen, the background trend extraction method proposed in this embodiment can effectively extract the information reflected by the background layered strata within the target section.

[0146] like Figure 6 As shown, comparison Figure 4 and Figure 6 The reflection of the caves in the figure is abnormal. It can be seen that the background suppression method proposed in this embodiment can effectively suppress the strong reflection of shallow layers and the interference of background strata on the carving of caves. In particular, the caves inside the ellipse in the figure have their boundaries clearly depicted.

[0147] like Figure 7 As shown in the figure, the development of karst caves was sculpted using a single threshold value. The arrows in the figure indicate the locations of the karst caves in the forward model. (The text then abruptly shifts to a different topic:) Figure 2 and Figure 7 As can be seen, the karst cave depiction method proposed in this invention can effectively depict the karst cave boundary and eliminate the influence of shallow reflection strong axis and background strata, thus effectively improving the carving accuracy of karst cave.

[0148] Example 2

[0149] like Figure 1 As shown, a method for characterizing a fracture-controlled cavity-type reservoir includes:

[0150] Step 1: Obtain the three-dimensional seismic reflection amplitude data D, and based on the three-dimensional seismic reflection amplitude data D, obtain the three-dimensional relative impedance data;

[0151] Step 2: Based on the three-dimensional relative impedance data, obtain the relative impedance pseudo-well curve at the well point. Then, based on the mid-to-low frequency data from the relative impedance pseudo-well curve and the P-wave impedance logging curve, derive the conversion formula between P-wave impedance and relative impedance, and subsequently calculate the absolute impedance data I. p

[0152] Step 3: Based on absolute impedance data I p Using the three-dimensional seismic reflection amplitude data D, and under the control of the three-dimensional trend of the structural horizon, a three-dimensional sliding window V is selected, and the absolute impedance data I is calculated based on the selected three-dimensional sliding window V. p Impedance background trend I p_bg The amplitude background trend of the three-dimensional seismic reflection amplitude data D bg ;

[0153] Step 4: Calculate the absolute impedance data I p and impedance background trend I p_bg The difference between them yields the impedance data I after background trend suppression. p_diff And calculate the three-dimensional seismic reflection amplitude data D and the amplitude background trend D. bgThe difference between the background trend and the seismic amplitude data D is obtained diff ;

[0154] The karst cave response is calculated based on the background trend suppressed impedance data I p_diff The fracture-cave zone response is calculated based on the background trend suppressed seismic amplitude data D diff .

[0155] As shown in Figure 8 , the fracture-cave zone numerical model based on the measured data is added to the karst cave numerical model in Figure 2 , and the fracture-cave zone numerical model is an equivalent model of the fracture-cave zone. According to the actual data, the region where the fracture-cave zone may develop is valued, which is different from the background stratum and the karst cave. The specific position is marked with a dashed line in the figure. Based on the model, the reflection coefficient is calculated, and then the seismic synthetic record is obtained by convolution with the Ricker wavelet of the main frequency of 25 Hz, as shown in Figure 9 . Comparing Figure 3 and Figure 9 , it can be seen that the addition of the fracture-cave zone causes the change of the seismic reflection amplitude.

[0156] As shown in Figure 10 , the fracture-cave zone can cause the change of the seismic reflection amplitude, and the energy envelope can highlight the seismic reflection anomaly. Based on the reflection amplitude in Figure 9 , the result of calculating the energy envelope is shown in Figure 10 . The range marked with a dashed line in the figure is the development position of the fracture-cave zone in the numerical model. As can be seen from the figure, due to the influence of the background stratum, it is difficult to accurately depict the development range of the fracture-cave zone by directly calculating the energy envelope, see the position pointed by the arrow in Figure 10 .

[0157] As shown in Figure 11 , the range marked with a dashed line in the figure is the development position of the fracture-cave zone in the numerical model. By comparing Figure 10 and Figure 11 , it can be seen that the method proposed in the present application can effectively identify the development position of the fracture-cave zone, so that the depiction accuracy of the fracture-cave zone is greatly improved.

[0158] As shown in Figure 12 , the results obtained by post-stack inversion based on measured seismic data (a) and the karst cave depiction method proposed in the present application (b) are compared. As can be seen by comparison, the karst cave depiction method proposed in the present application can effectively highlight the karst cave submerged in the background stratum.

[0159] As shown in Figure 13As shown, the results obtained by the energy envelope calculation based on the measured seismic data (a) and the fracture-cave zone carving method (b) proposed in the present application are compared, and it can be seen from the comparison that the fracture-cave zone carving method proposed in the present application can effectively suppress the interference of shallow strong reflection and background reflection, and improve the recognition accuracy of the fracture-cave zone.

[0160] As shown in the figure, the results of the dissolution cave and fracture-cave zone recognition based on the measured seismic data (a) are compared (b), and the comprehensive constraint of the dissolution cave and the fracture-cave zone can effectively reduce the multi-solution of the fracture-cave zone carving of the fault-controlled reservoir, and the predicted reservoir zone and the loss of the well point are consistent, which can provide high-quality data support for subsequent reservoir analysis. Figure 14 Embodiment 3

[0161] The present disclosure provides an electronic device, which includes a memory storing executable instructions, and a processor running the executable instructions in the memory to implement the fracture-cave type reservoir carving method.

[0162] The electronic device according to the embodiments of the present disclosure includes a memory and a processor.

[0163] The memory is configured to store non-transitory computer-readable instructions. Specifically, the memory can include one or more computer program products, which can 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), cache memory, and / or the like. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, and / or the like.

[0164] The processor can be a central processing unit (CPU) or other forms of processing units with data processing and / or instruction execution capabilities, and can control other components in the electronic device to perform desired functions. In an embodiment of the present disclosure, the processor is configured to run the computer-readable instructions stored in the memory.

[0165] Those skilled in the art should understand that, in order to solve the technical problem of how to obtain a good user experience effect, the present embodiment can also include well-known structures such as a communication bus, an interface, and the like, which should also be included in the protection scope of the present disclosure.

[0166] The detailed description of the present embodiment can refer to the corresponding description in the foregoing embodiments, which will not be repeated here.

[0167] Embodiment 4

[0168] The detailed description of the present embodiment can refer to the corresponding description in the foregoing embodiments, which will not be repeated here.

[0169] This disclosure provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for characterizing a fracture-controlled cavity-type reservoir.

[0170] A computer-readable storage medium according to embodiments of the present disclosure stores non-transitory computer-readable instructions. When these non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the methods described in the foregoing embodiments of the present disclosure are performed.

[0171] The aforementioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or portable hard drive), media with built-in rewritable non-volatile memory (e.g., memory card), and media with built-in ROM (e.g., ROM cartridge).

[0172] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations 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 characterizing a fracture-controlled cavitation reservoir, characterized in that, include: Step 1: Obtain 3D seismic reflection amplitude data Based on the three-dimensional seismic reflection amplitude data This yields three-dimensional relative impedance data; Step 2: Based on the three-dimensional relative impedance data, obtain the relative impedance pseudo-well curve at the well point, and based on the mid-to-low frequency data in the relative impedance pseudo-well curve and the P-wave impedance logging curve, obtain the conversion relationship formula between P-wave impedance and relative impedance, and then calculate the absolute impedance data. ; Step 3: Based on the absolute impedance data and the three-dimensional seismic reflection amplitude data Under the control of the three-dimensional trend of the structural layer, a three-dimensional sliding window is selected. And based on the selected three-dimensional sliding window Calculate the absolute impedance data respectively. Impedance background trend and the three-dimensional seismic reflection amplitude data Amplitude background trend ; Step 4: Calculate the absolute impedance data and the aforementioned impedance background trend The difference between them yields the impedance data after background trend suppression. And calculate the three-dimensional seismic reflection amplitude data. and the aforementioned amplitude background trend The difference between them yields the earthquake amplitude data after background trend suppression. ; Step 5: Impedance data after suppression based on the background trend. The cave response was calculated based on the earthquake amplitude data suppressed by the background trend. The response of the fracture zone was calculated.

2. The method for characterizing a fracture-controlled cavity-type reservoir according to claim 1, characterized in that, Step 1 includes: Step 11: Obtain 3D seismic reflection amplitude data , as well as logging velocity data or seismically interpreted velocity data; Step 12: Use the logging velocity data or the seismic interpretation velocity data to perform time-domain and depth-domain calibration to obtain time-depth calibration results; Step 13: Based on the time-depth calibration results, estimate the wavelet corresponding to the target layer segment. ; Step 14: Based on the three-dimensional seismic reflection amplitude data and the wavelet The relative impedance is calculated, and then the three-dimensional relative impedance data is obtained.

3. The method for characterizing a fracture-controlled cavity-type reservoir according to claim 1, characterized in that, Step 2 includes: Step 21: Based on the three-dimensional relative impedance data, obtain the relative impedance pseudo-well curve at the well point, and based on the relative impedance pseudo-well curve and the mid-to-low frequency curve in P-wave impedance logging, obtain the conversion relationship formula between P-wave impedance and relative impedance, and then obtain the low-frequency trend model. ; Step 22: Based on the low-frequency trend model Construct low-frequency constraint expressions ; Step 23: Based on the low-frequency constraint expression Construct the inversion objective function ; Step 24: Obtain the wavelet matrix corresponding to the target layer. Substitute into the inversion objective function In the process, the longitudinal wave impedance reflectivity is obtained. ; Step 25: The longitudinal wave impedance reflectivity Substituting into the following formula, we obtain the absolute impedance data. , ， in, Sampling time, This represents the absolute value of the longitudinal wave impedance at the initial moment in the low-frequency trend model. For sampling time is The longitudinal wave impedance reflectivity at that time.

4. The method for characterizing a fracture-controlled cavitation reservoir according to claim 3, characterized in that, Step 21 includes: Based on the three-dimensional relative impedance data, the relative impedance pseudo-well curve at the well point is obtained; Obtain the raw P-wave impedance data from the well log; The raw P-wave impedance data from the well logging are sequentially subjected to low-pass filtering and resampling to obtain the measured P-wave impedance logging curve at the well point. By intersecting the measured P-wave impedance logging curve and the relative impedance pseudo-log curve, a conversion relationship formula between the P-wave impedance and the relative impedance is obtained. Based on the aforementioned conversion formula, the three-dimensional relative impedance data is transformed into the low-frequency trend model. .

5. The method for characterizing a fracture-controlled cavitation reservoir according to claim 3, characterized in that, The low-frequency constraint expression for ， in, To adjust the hyperparameters of the weights of low-frequency constraint terms, This is a low-pass filter matrix. Let be an integral matrix. The longitudinal wave impedance reflectivity; The inversion objective function for ， in, The wavelet matrix corresponding to the target layer. For sparse constraint terms, is the weight adjustment parameter for the sparse constraint term.

6. The method for characterizing a fracture-controlled cavity-type reservoir according to claim 1, characterized in that, Step 3 includes: Based on the absolute impedance data and the three-dimensional seismic reflection amplitude data Following the stratigraphic trend and controlled by the development trend of the tectonic strata, the three-dimensional sliding window is selected. The three-dimensional sliding window Includes One sampling point; Following the aforementioned layered structural trend, with any sampling point as the center point, the three-dimensional sliding window is... The contents of the above The sampling points are rearranged so that The three-dimensional sliding window is obtained. Median of the inner samples The median is used as the three-dimensional sliding window. The center, where V i For window The i-th sampling point; Based on the three-dimensional sliding window The median of the inner samples is used to calculate the absolute impedance data. Impedance background trend and the three-dimensional seismic reflection amplitude data Amplitude background trend .

7. The method for characterizing a fracture-controlled cavity-type reservoir according to claim 1, characterized in that, ， in, This represents the absolute impedance data. This indicates the background impedance trend. This represents the impedance data after the background trend was suppressed; ， in, This represents the three-dimensional seismic reflection amplitude data. This indicates the background trend of the amplitude.

8. The method for characterizing a fracture-controlled cavitation reservoir according to claim 1, characterized in that, Step 5 includes: Impedance data after suppressing the background trend Substituting into the enhanced calculation formula for the karst cave response, we obtain the karst cave response. The enhanced calculation formula for the solution cavity response is as follows: ， Where e is the natural index, Scaling factor and The value of is greater than 1; Earthquake amplitude data after suppressing the background trend Phase transformation was performed to obtain the abnormal amplitude of the fracture zone after repositioning. ; Based on the abnormal amplitude of the repositioned suture zone The response of the fracture zone was obtained through the energy envelope calculation formula. The formula for calculating the energy envelope is as follows: ， Where t is the sampling time, for The real part obtained after Hilbert transformation for The imaginary part obtained by the Hilbert transform.

9. An electronic device, characterized in that, The electronic device includes: Memory, which stores executable instructions; A processor that executes the executable instructions in the memory to implement the method for characterizing a fractured-slotted reservoir according to any one of claims 1-8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method for characterizing a fracture-controlled cavity reservoir as described in any one of claims 1-8.

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