A method, device, equipment and storage medium for correcting azimuth density gap while drilling

Abstract

The application discloses a method, device and equipment for correcting the azimuthal density gap while drilling, and a storage medium, and relates to the field of oil and gas development.The method comprises the following steps: inputting the detector density energy window count data corresponding to the target depth point in the target well into a density calculation formula used for representing the density calculation formula generated by the standard calibration well calibration of the azimuthal density instrument while drilling under different densities, and outputting the first density value of different detectors; determining the corresponding target radial density sensitivity function from the density sensitivity function database based on the first density value, and acquiring the second density value of the target well actually measured by the detector; inputting the first density value and the second density value into a cost function model, correcting the formation real density value and the gap in the target density response calculation formula containing the target radial density sensitivity function, and outputting the corrected target gap and target density value, so that the accurate gap value and the formation real density value are acquired.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas development, and particularly relates to a method, device, equipment and storage medium for borehole azimuth density gap correction. BACKGROUND

[0002] Formation density is one of the important parameters for reservoir evaluation, and is often used for formation lithology division, porosity calculation and shale content determination. In addition to the functions of conventional gamma-gamma density logging, borehole azimuth density can realize 360-degree density scanning imaging of wellbore through drill collar rotation, and further realize formation interface determination and formation dip angle calculation. In actual process, the irregular shape of the drilling wellbore and the vibration during measurement of the drilling instrument will cause a gap between the borehole azimuth density instrument and the well wall, and the size of the gap changes randomly and irregularly. The borehole azimuth density logging has a shallow detection depth and is very sensitive to the change of the wellbore environment. A small gap will lead to distortion of the formation density parameter measurement and low-resolution density imaging results, which is extremely unfavorable for reservoir evaluation and determination of formation structure parameters.

[0003] Exploration and development of tight unconventional oil and gas such as shale oil and shale gas have higher requirements for the measurement accuracy of borehole azimuth density, and the increasingly complex actual drilling environment also poses new challenges to the measurement of borehole azimuth density. The traditional gap correction method using ridge-rib graph and chart is no longer applicable to the gap correction of borehole azimuth density instrument.

[0004] In summary, how to correct the density measurement difference caused by the difference between the gap fluid and the formation medium, eliminate the influence of the gap fluid on the density measurement, and realize accurate calculation of the formation density is a technical problem to be solved in the field. SUMMARY

[0005] Therefore, the present application aims to provide a borehole azimuth density gap correction method, device, equipment and storage medium, which can correct the density measurement difference caused by the difference between the gap fluid and the formation medium, eliminate the influence of the gap fluid on the density measurement, and realize accurate calculation of the formation density. The specific scheme is as follows.

[0006] In a first aspect, the present application discloses a borehole azimuth density gap correction method, comprising:

[0007] The detector density energy window count data corresponding to the target depth point in the target drilling well is input into a density calculation formula for characterizing the density calculation formula generated by the borehole azimuth density instrument in the standard calibration well with different densities, so as to output the first density value of different detectors;

[0008] determine a corresponding target radial density sensitivity function from a density sensitivity function database based on the first density value, and obtain a second density value of the target well actually measured by the detector;

[0009] input the first density value and the second density value into a cost function model, so that the cost function model corrects the formation true density value and the gap in a target density response calculation formula containing the target radial density sensitivity function, and outputs the corrected target gap and target density value.

[0010] Optionally, before the target detector density energy window count data corresponding to the target depth point in the target well is input into the density calculation formula used for characterizing the density calibration of the while-drilling azimuthal density instrument in the standard calibration well at different densities, the method further comprises:

[0011] calibrating the while-drilling azimuthal density instrument in the standard calibration well at different densities, and constructing a density calculation formula of the first density value measured by the detector.

[0012] Optionally, before the corresponding target radial density sensitivity function is determined from the density sensitivity function database based on the density value, the method further comprises:

[0013] adding the radial density sensitivity function to the density response calculation formula to construct a target density response calculation formula containing the reference formation density value, the mud density value, the formation true density value and the radial density sensitivity function.

[0014] Optionally, before the radial density sensitivity function is added to the density response calculation formula, the method further comprises:

[0015] constructing the radial density sensitivity function based on the gap value between the while-drilling azimuthal density instrument and the well wall of the target well, the gamma ray flux corresponding to the gap value, the detector density energy window count data corresponding to the reference formation density value and the importance function.

[0016] Optionally, before the corresponding target radial density sensitivity function is determined from the density sensitivity function database based on the first density value, the method further comprises:

[0017] constructing a sensitivity function simulation model according to the structural parameters of the while-drilling azimuthal density instrument, so as to simulate the radial density sensitivity function and the instrument response characteristics under different reference formation density conditions by using the sensitivity function simulation model, and to construct a density sensitivity function database.

[0018] Optionally, the first density value and the second density value are input into a cost function model, so that the cost function model corrects the formation true density value and the gap in a target density response calculation formula containing a target radial density sensitivity function, including:

[0019] The first density value and the second density value are input into a cost function model, and an iterative step is determined by using an L-M method to determine the minimum value of the absolute value of the cost function, and the size relationship between the minimum value and a target threshold is judged;

[0020] If the minimum value is less than the target threshold, the formation true density value and the gap value are output;

[0021] If the minimum value is greater than and / or equal to the target threshold, the formation true density value and the gap value are corrected until the minimum value is less than the target threshold.

[0022] Optionally, before the first density value and the second density value are input into the cost function model, the method further includes:

[0023] A cost function model is constructed by using a target weight, an L2 norm of the difference between the first density value and the second density value, a regularization parameter, a formation true density value, a gap, and a borehole fluid density.

[0024] In a second aspect, the present application discloses a device for correcting the gap of the azimuthal density while drilling, including:

[0025] A first density determination module is configured to input the detector density energy window count data corresponding to the target depth point in the target drilling into a density calculation formula for representing the density calculation formula generated by the different density standard calibration well calibration of the azimuthal density instrument while drilling, so as to output the first density value of different detectors;

[0026] A second density determination module is configured to determine the corresponding target radial density sensitivity function from the density sensitivity function database based on the first density value, and obtain the second density value of the target drilling actually measured by the detector;

[0027] A density gap determination module is configured to input the first density value and the second density value into a cost function model, so that the cost function model corrects the formation true density value and the gap in the target density response calculation formula containing the target radial density sensitivity function, and outputs the corrected target gap and target density value.

[0028] In a third aspect, the present application discloses an electronic device, including:

[0029] A memory is configured to save a computer program;

[0030] A processor is configured to execute the computer program to implement the steps of the method for correcting the borehole azimuthal density gap.

[0031] In a fourth aspect, the present application discloses a computer readable storage medium for storing a computer program, wherein the computer program is configured to implement the steps of the method for correcting the borehole azimuthal density gap when executed by a processor.

[0032] It can be seen that the present application discloses a method for correcting the borehole azimuthal density gap, which comprises the following steps: inputting the detector density energy window count data corresponding to the target depth point in the target well into a density calculation formula for characterizing the density calculation formula generated by the borehole azimuthal density instrument in the standard calibration well with different densities, so as to output the first density value of different detectors; determining the corresponding target radial density sensitivity function from the density sensitivity function database based on the first density value, and obtaining the second density value of the target well actually measured by the detector; inputting the first density value and the second density value into the cost function model, so that the cost function model corrects the formation true density value and the gap in the target density response calculation formula containing the target radial density sensitivity function, and outputs the corrected target gap and target density value. It can be seen that, by inputting the density energy window count data of the target depth point of the target well detected by the detector into the standard density calculation formula, the first density value of the detector is determined, and the corresponding target radial density sensitivity function is determined from the function database based on the first density value and the function correspondence relationship, and then the actual density value of the target well measured by the detector, i.e. the second density value, is obtained. The first density value and the second density value are input into the cost function model, the target density value and the target gap are inversely solved by the cost function model, and are corrected to obtain the accurate gap value and the formation true density value. The calculation speed is fast, the precision is high, and the influence of the wellbore gap and the wellbore fluid density is small. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on the provided drawings.

[0034] Figure 1 A flow chart of the method for correcting the borehole azimuthal density gap disclosed by the present application;

[0035] Figure 2 A flow chart of the iterative inversion of the borehole azimuthal density gap disclosed by the present application;

[0036] Figure 3A specific while-drilling azimuthal density gap correction method flow chart disclosed in the application;

[0037] Figure 4 A far detector numerical calculation model XZ view of a while-drilling azimuthal density instrument disclosed in the application;

[0038] Figure 5 A far detector numerical calculation model XY view of a while-drilling azimuthal density instrument disclosed in the application;

[0039] Figure 6 A near detector radial density sensitivity function disclosed in the application;

[0040] Figure 7 A far detector radial density sensitivity function disclosed in the application;

[0041] Figure 8 A gap correction before and after comparison result chart disclosed in the application;

[0042] Figure 9 A while-drilling azimuthal density gap correction device structural schematic view disclosed in the application;

[0043] Figure 10 An electronic device structural view disclosed in the application. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the application will be clearly and completely described in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0045] Formation density is one of important parameters for reservoir evaluation, and is often used for formation lithology division, porosity calculation and shale content determination. While-drilling azimuthal density has the functions of conventional gamma-gamma density logging, and can realize 360-degree density scanning imaging of a borehole through drill collar rotation, and further realize formation interface determination and formation dip angle calculation. In actual process, irregular shape of a drilling borehole and vibration during measurement of a while-drilling instrument will cause a gap between the while-drilling azimuthal density instrument and a well wall, and the size of the gap presents irregular random change. While-drilling azimuthal density logging has a shallow detection depth, and is very sensitive to change of a borehole environment. A small gap will cause distortion of formation density parameter measurement and low-resolution density imaging result, which is extremely unfavorable for reservoir evaluation and determination of formation structure parameters.

[0046] The exploration and development of tight unconventional oil and gas such as shale oil and shale gas put forward higher requirements for the measurement accuracy of the while-drilling azimuthal density, and the increasingly complex actual drilling environment also puts forward new challenges to the while-drilling azimuthal density measurement, and the traditional gap correction method using the ridge-rib diagram and the chart has not been applicable to the gap correction of the while-drilling azimuthal density instrument.

[0047] Therefore, the application provides a while-drilling azimuthal density gap correction scheme, which can correct the density measurement difference caused by the difference between the gap fluid and the formation medium, eliminate the influence of the gap fluid on the density measurement, and realize accurate calculation of the formation density.

[0048] Referring to Figure 1 The application discloses a while-drilling azimuthal density gap correction method, which comprises the following steps:

[0049] In step S11, the detector density energy window count data corresponding to the target depth point in the target well are input into a density calculation formula for characterizing the density calculation formula generated by the while-drilling azimuthal density instrument in the standard calibration well with different densities, so as to output the first density values of different detectors.

[0050] In this embodiment, the density gap correction is realized by the gamma source, the ultrasonic caliper detector and the at least two gamma detectors in the axial direction. Specifically, the density energy window count data of the far gamma detector and the near gamma detector are input into the density calculation formula, so as to output the first density values corresponding to the far gamma detector and the near gamma detector respectively through the density calculation formula.

[0051] In this embodiment, before the detector density energy window count data corresponding to the target depth point in the target well are input into the density calculation formula for characterizing the density calculation formula generated by the while-drilling azimuthal density instrument in the standard calibration well with different densities, the while-drilling azimuthal density instrument is calibrated in the standard calibration well with different densities, and the density calculation formula of the first density value measured by the detector is constructed. It can be understood that the while-drilling azimuthal density instrument is calibrated in the standard calibration well with different densities to generate corresponding calibration data, and the density calculation formula for calculating the first density value is constructed, and the specific formula is as follows:

[0052]

[0053] N SS represents the count value in the density energy window range of the near gamma detector, N L represents the count value in the density energy window range of the far gamma detector, a1, b1, a2 and b2 respectively represent the related constants of the near gamma detector and the far gamma detector, and the specific values can be obtained by fitting the calibration data; p SS represents the first density value measured by the near gamma detector, and p Ldenotes a first density value measured by a far gamma detector.

[0054] Step S12: determining a corresponding target radial density sensitivity function from a density sensitivity function database based on the first density value, and obtaining a second density value of the target well actually measured by the detector.

[0055] In the embodiment, the corresponding target radial density sensitivity function is determined from the density sensitivity function database according to the first density value, specifically, a reference formation density value ρ0 and a corresponding target radial density sensitivity function are selected, and a second density value of the target well actually measured by the detector is obtained, wherein the well data is specifically a mud density value, an ultrasonic well diameter, a formation true density value, and the like of the target well.

[0056] In the embodiment, before the corresponding target radial density sensitivity function is determined from the density sensitivity function database based on the density value, the radial density sensitivity function is added to a density response calculation formula to construct a target density response calculation formula containing the reference formation density value, the mud density value, the formation true density value, and the radial density sensitivity function. It can be understood that the radial density sensitivity function is added to the density response calculation formula, and the Taylor expansion is performed on the density response calculation formula to obtain an expression form of the radial density sensitivity function, that is, the density response calculation formula, and the specific formula expression is as follows:

[0057]

[0058] wherein ρ denotes a first density value measured by a far and / or near gamma detector, and the unit is g / cm 3 ; ρ0 denotes a reference bottom layer density value, ρ mud is a mud density value, ρ b is a formation true density value, and the unit is g / cm 3 ; r is a gap value between the while-drilling azimuthal density instrument and the well wall of the target well, and the unit is cm; k1 is a constant coefficient, and PSF(r) is a radial density sensitivity function.

[0059] In the embodiment, the adding the radial density sensitivity function to the density response calculation formula further comprises: constructing the radial density sensitivity function based on the gap value between the while-drilling azimuthal density instrument and the well wall of the target well, the gamma ray flux corresponding to the gap value, the detector density energy window count data corresponding to the reference formation density value, and the importance function. It can be understood that the radial density sensitivity function is constructed based on the gap value between the while-drilling azimuthal density instrument and the well wall of the target well, the gamma ray flux corresponding to the gap value, the detector density energy window count data corresponding to the reference formation density value, and the importance function. It should be noted that the selected while-drilling azimuthal density instrument includes one gamma source and at least two axial gamma detectors, and the method is applicable to a double-source instrument with multiple gamma detectors distributed in each source. In addition, ultrasonic caliper measurement data, i.e., the second density value, is required in the actual calculation process. The calculation formula of the radial density sensitivity function is as follows:

[0060]

[0061] wherein N0 represents the count value of the gamma detector when the reference formation density value is p0; Φ0(r, Ω') represents the gamma ray flux at the space r under the condition that the current reference formation density value is p0; G(r, Ω'→r, Ω) represents the importance function; and PSF(r) is only related to the radial distance, so in the above cylindrical coordinate system, the axial z and the circumferential θ are integrated in all space ranges. The gamma ray flux and the importance function can be obtained by numerical simulation. D D

[0062] Step S13: inputting the first density value and the second density value into the cost function model, so that the cost function model corrects the formation true density value and the gap in the target density response calculation formula containing the target radial density sensitivity function, and outputs the corrected target gap and target density value.

[0063] In the embodiment, the first density value and the second density value are input into the cost function model, the formation true density value and the gap value in the target density response calculation formula are calculated by the cost function model, and the corrected formation true density value and gap value are output. For details, refer to the description of the step S13. Figure 2 ​​As shown, by inputting the count value in the energy window range of the near and far gamma detectors, the first density value corresponding to the gamma detector is calculated, then the corresponding reference formation density value and target radial sensitivity function are selected, and the gap value is inverted by combining the drilling data, such as the mud density value, the ultrasonic hole diameter value, and the formation true density value, and the inversion result is compared with the threshold value set in advance, and the formation true density value and the gap value are output. Specifically, at a certain depth point, first, the near and far detector density window counts N SS and N L are input, the near and far detector density values ρ SS and ρ L are calculated by using the density calculation formula, then the reference formation density value with a density close to ρ L is selected as the reference formation condition of the reference formation density value ρ0, the target radial sensitivity function of the near and far detectors corresponding to the reference formation condition is selected, the mud density ρ mud and the ultrasonic hole diameter r at the time of drilling are given as the initial value parameters, the apparent density of the near and far detectors is calculated, the iteration step is determined by using the L-M method, and the minimum value of the absolute value of the function is obtained.

[0064] It can be seen that the present application discloses a method for correcting the azimuthal density gap while drilling, which comprises: inputting the detector density energy window count data corresponding to the target depth point of the target well in the target drilling into a density calculation formula for characterizing the density calculation formula generated by the standard calibration well calibration of the azimuthal density instrument while drilling at different densities, so as to output the first density value of different detectors; determining the corresponding target radial density sensitivity function from the density sensitivity function database based on the first density value, and obtaining the second density value of the target well actually measured by the detector; inputting the first density value and the second density value into a cost function model, so that the cost function model corrects the formation true density value and the gap in the target density response calculation formula containing the target radial density sensitivity function, and outputs the corrected target gap and target density value. It can be seen that by inputting the density energy window count data of the target depth point of the target well detected by the detector into the standard density calculation formula, the first density value of the detector is determined, and the corresponding target radial density sensitivity function is determined from the function database based on the first density value and the function corresponding relationship, and then the actual density value of the target well measured by the detector, i.e. the second density value, is obtained. The first density value and the second density value are input into the cost function model, the target density value and the target gap are inversely solved and corrected by the cost function model, and the accurate gap value and the formation true density value are obtained. The calculation speed is fast, the precision is high, and the influence of the wellbore gap and the wellbore fluid density is small.

[0065] Reference Figure 3As shown, the embodiment of the present application discloses a specific method for correcting the azimuthal density gap while drilling, and the embodiment further describes and optimizes the technical solution relative to the previous embodiment. Specifically,

[0066] Step S21: input the detector density energy window count data corresponding to the target depth point in the target well into a density calculation formula for characterizing the density calibration produced by the azimuthal density instrument while drilling in different density standard calibration wells, so as to output the first density values of different detectors.

[0067] Step S22: construct a sensitivity function simulation model according to the structural parameters of the azimuthal density instrument while drilling, so as to simulate the radial density sensitivity function and instrument response characteristics under different reference formation density conditions by using the sensitivity function simulation model, and construct a density sensitivity function database.

[0068] In this embodiment, a Monte Carlo numerical calculation model, i.e., a sensitivity function simulation model, is established according to the selected structural parameters of the azimuthal density instrument while drilling, which is used to simulate the radial density sensitivity function and instrument response characteristics under different reference density formation conditions, and construct a density sensitivity function database, as shown in Figure 4 and Figure 5 As shown, the sensitivity function simulation model includes a gamma source 1, a source collimating port 2, a tungsten-nickel-iron shielding body 3, a near detector window 4, a far detector window 5, a formation 6, a borehole 7, a far gamma detector 8, a near gamma detector 9, a mud flow channel 10, and a drill collar 11. In the numerical calculation process, the formation is divided into grid units with a thickness of 0.25 cm along the radial direction to improve the accuracy of the radial density sensitivity function. The simulation results of the radial density sensitivity functions of the near and far gamma detectors are shown in Figure 6 and Figure 7 As shown, with the increase of the radial distance, the radial density sensitivity function first increases and then decreases, and the radial sensitivity functions corresponding to different reference formation densities have obvious differences, so in the actual processing process, it is necessary to establish a near and far gamma detector density sensitivity function database with a density range of 1.0 g / cm 3 ~ 3.2 g / cm 3 and a density interval of 0.1 g / cm 3 It should be noted that the density sensitivity function database is matched with the azimuthal density instrument while drilling, and if the structure of the azimuthal density instrument while drilling changes, the density sensitivity function database needs to be re-constructed. For example, taking a dual-detector azimuthal density instrument while drilling as an example, a Monte Carlo numerical calculation model is established, the formation is divided into layered formations with a thickness of 0.5 cm along the radial direction, and the radial sensitivity function is simulated. In addition, the detection depth and the longitudinal resolution of the azimuthal density instrument while drilling are simulated by changing the properties of the formation, and the two constitute the effective detection area of the azimuthal density instrument while drilling.

[0069] Step S23: determining a corresponding target radial density sensitivity function from the density sensitivity function database based on the first density value, and obtaining a second density value of the target well actually measured by the detector.

[0070] Step S24: inputting the first density value and the second density value into a cost function model, determining an iterative step length by using an L-M method, determining a minimum value of an absolute value of the cost function, and judging a size relationship between the minimum value and a target threshold value.

[0071] In the embodiment, the L-M optimization method is used to inversely solve the cost function model, and a program is written to obtain an accurate formation density value through iterative calculation. Specifically, an iterative step length is determined, and then a minimum value of an absolute value of the cost function in the cost function model is determined, and a size relationship between the minimum value and a target threshold value is judged.

[0072] In the embodiment, before the first density value and the second density value are input into the cost function model, the method further comprises: constructing a cost function model by using a target weight, an L2 norm of a difference between the first density value and the second density value, a regularization parameter, a real formation density value, a gap, and a wellbore fluid density. It can be understood that the cost function model is established as follows:

[0073]

[0074] wherein the first term calculates an L2 norm of a difference between a measured while-drilling azimuthal density response vector S(p) and a measured while-drilling azimuthal density instrument measurement d s , i.e., e(p) = S(p) - d s , p is a parameter vector to be inverted, including a formation density, a wellbore fluid density, and a gap. The second term is a regularization term, which mainly prevents overfitting and suppresses errors caused by statistical fluctuations of radioactivity, p0 is an initial formation nuclear characteristic parameter reference vector, λ is a regularization parameter, W A , and W B are weights.

[0075] The Taylor expansion is performed on the above cost function model, and a second order obtained is as follows:

[0076]

[0077] wherein Δp is a small perturbation near the vector p, g is a derivative of the cost function C(p) with respect to the vector p, H is a Hessian matrix, and (Δp) T is a transpose of the vector Δp. The L-M method is iteratively calculated to obtain an accurate value of the formation density

[0078] Step S25: if the minimum value is less than the target threshold value, output the formation true density value and the gap value.

[0079] In this embodiment, if the minimum value obtained by the above point-by-point inversion is less than the given target threshold value ε, the formation true density value ρ b and the gap value r are output.

[0080] Step S26: if the minimum value is greater than and / or equal to the target threshold value, correct the formation true density value and the gap value until the minimum value is less than the target threshold value.

[0081] In this embodiment, if the minimum value obtained by the above point-by-point inversion is greater than and / or equal to the given target threshold value ε, the reference formation density value and the borehole gap are corrected, specifically, the step of selecting the corresponding target radial sensitivity function is executed until the minimum value is less than the target threshold value, satisfying the result output condition. As shown in Figure 8 , when the borehole fluid is clear water and the gap is 1 cm and 2 cm respectively, the calculation results of this method are given. After gap correction, the calculated formation density value is consistent with the true value of the formation density, and the error is basically within ±0.025 g / cm 3 .

[0082] As can be seen, the radial density sensitivity function under different reference density formation conditions is simulated by using the Monte Carlo numerical simulation method, a near and far detector sensitivity function database of the while-drilling azimuthal density instrument is established, the corresponding target radial sensitivity function in the library is used to cause, the density measurement difference caused by the difference between the gap fluid and the formation medium is represented, and the influence of the gap fluid on the density measurement is eliminated through the iterative inversion of the cost function model, so that the accurate calculation of the formation density is realized.

[0083] Referring to Figure 9 , the present embodiment also discloses a while-drilling azimuthal density gap correction device, which comprises:

[0084] A first density determination module 11 is configured to input the detector density energy window count data corresponding to the target depth point in the target well into a density calculation formula for representing the density calculation formula generated by the while-drilling azimuthal density instrument in different density standard calibration wells, so as to output the first density value of different detectors.

[0085] A second density determination module 12 is configured to determine the corresponding target radial density sensitivity function from the density sensitivity function database based on the first density value, and obtain the second density value of the target well actually measured by the detector.

[0086] The density gap determination module 13 is configured to input the first density value and the second density value into a cost function model, so that the cost function model corrects the formation true density value and the gap in a target density response calculation formula containing a target radial density sensitivity function, and outputs a corrected target gap and a target density value.

[0087] Therefore, the application discloses a method for correcting a drilling azimuthal density gap, which comprises the following steps: inputting density energy window counting data of a target depth point in a target well into a density calculation formula used for characterizing density calculation of a standard calibration well calibrated by a drilling azimuthal density instrument at different densities, so as to output a first density value of different detectors; determining a corresponding target radial density sensitivity function from a density sensitivity function database based on the first density value, and obtaining a second density value of the target well actually measured by the detector; inputting the first density value and the second density value into a cost function model, so that the cost function model corrects a formation true density value and a gap in a target density response calculation formula containing the target radial density sensitivity function, and outputs a corrected target gap and a target density value. It can be seen that, by inputting the density energy window counting data of the target depth point of the target well detected by the detector into the standard density calculation formula, the first density value of the detector is determined, the corresponding target radial density sensitivity function is determined from the function database based on the first density value and the function corresponding relationship, and then the actual density value of the target well measured by the detector, that is, the second density value, is obtained. The first density value and the second density value are input into the cost function model, the target density value and the target gap are inversely solved by the cost function model, and are corrected, so that the accurate gap value and the formation true density value are obtained. The calculation speed is high, the accuracy is high, and the influence of the wellbore gap and the wellbore fluid density is small.

[0088] Further, the application also discloses an electronic device, Figure 10 The electronic device 20 shown in FIG. 1 is merely an example, and the application is not limited to the electronic device 20 shown in FIG. 1.

[0089] Figure 10 The electronic device 20 shown in FIG. 1 is merely an example, and the application is not limited to the electronic device 20 shown in FIG. 1.

[0090] In this embodiment, the power supply 23 is configured to provide operating voltage for each hardware device on the electronic device 20; the communication interface 24 is configured to create a data transmission channel between the electronic device 20 and external devices, and the communication protocol followed by the communication interface 24 can be any communication protocol applicable to the technical solution of the present application, which will not be specifically limited herein; the input and output interface 25 is configured to obtain external input data or output data to the outside, and the specific interface type can be selected according to the specific application requirements, which will not be specifically limited herein.

[0091] The processor 21 can include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 21 can be implemented in at least one of a hardware form of a DSP (Digital Signal Processing), an FPGA (Field-Programmable Gate Array), and a PLA (Programmable Logic Array). The processor 21 can also include a main processor and a coprocessor. The main processor is a processor for processing data in a wake-up state, also known as a CPU (Central Processing Unit). The coprocessor is a low-power processor for processing data in a standby state. In some embodiments, the processor 21 can be integrated with a GPU (Graphics Processing Unit) that is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 21 can also include an AI (Artificial Intelligence) processor configured to process machine learning-related computing operations.

[0092] In addition, the memory 22, as a carrier for storing resources, can be a read-only memory, a random access memory, a magnetic disk, or an optical disk, etc. The resources stored thereon can include an operating system 221, a computer program 222, etc., and the storage mode can be temporary storage or permanent storage.

[0093] The operating system 221 is used to manage and control each hardware device on the electronic device 20 and the computer program 222, so as to realize the operation and processing of the processor 21 on the mass data 223 in the memory 22, which can be Windows Server, Netware, Unix, Linux, etc. In addition to the computer program capable of completing the computer program executed by the electronic device 20 in the foregoing embodiments, the computer program 222 can further include a computer program capable of completing other specific work. In addition to the data received by the electronic device from the external device, the data 223 can also include the data collected by the self input and output interface 25, etc.

[0094] Further, the application further discloses a computer readable storage medium for storing a computer program; wherein the computer program is executed by a processor to realize the foregoing disclosed while drilling azimuthal density gap correction method. The specific steps of the method can refer to the corresponding contents disclosed in the foregoing embodiments, and will not be described here.

[0095] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts of each embodiment can be referred to each other. For the device disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the related parts can refer to the method part.

[0096] The skilled person can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the present text can be realized by electronic hardware, computer software or combination of both. In order to clearly show the interchangeability of hardware and software, the composition and steps of each example have been described in the above description. Whether the functions are realized by hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application. The steps of the method or algorithm described in combination with the embodiments disclosed in the present text can be directly implemented by hardware, software module executed by processor or combination of both. The software module can be placed in random access memory (RAM), memory, read only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, register, hard disk, removable disk, CD-ROM or any other form of storage medium known in the art.

[0097] Finally, it needs to be pointed out that, in this article, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the term "includes", "contains" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "includes a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0098] The above describes in detail the method, device, equipment and storage medium provided by the present application. The principles and implementation manners of the present application are described by using specific examples. The above description of the embodiments is only used to help understand the method of the present application and its core idea. Meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges can be changed. In summary, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A method for azimuthal density gap correction while drilling, characterized in that, The method comprises the following steps: inputting the detector density energy window count data corresponding to the target depth point in the target well into a density calculation formula for characterizing the first density value generated by the standard calibration well calibration of the while-drilling azimuthal density instrument at different densities, so as to output the first density value of different detectors; determining the corresponding target radial density sensitivity function from the density sensitivity function database based on the first density value, and obtaining the second density value of the target well actually measured by the detector; inputting the first density value and the second density value into a cost function model, so that the cost function model corrects the formation true density value and the gap in the target density response calculation formula containing the target radial density sensitivity function, and outputs the corrected target gap and target density value; Before the step of determining the corresponding target radial density sensitivity function from the density sensitivity function database based on the density value, the method further comprises the following steps: adding the radial density sensitivity function to the density response calculation formula to construct a target density response calculation formula containing the reference formation density value, the mud density value, the formation true density value and the radial density sensitivity function; wherein the density response calculation formula is: ； wherein, is a first density value measured as a far and / or near gamma detector, in g / cm 3 ; is a reference base layer density value, is a mud density value, is a formation true density value, in g / cm 3 ; r is a clearance value between the while-drilling azimuthal density instrument and the wellbore of the target well, in cm; is a constant coefficient, is a radial density sensitivity function; Before the step of determining the corresponding target radial density sensitivity function from the density sensitivity function database based on the first density value, the method further comprises the following steps: constructing a sensitivity function simulation model according to the structural parameters of the while-drilling azimuthal density instrument, so as to simulate the radial density sensitivity function and the instrument response characteristics under different reference formation density conditions by using the sensitivity function simulation model, so as to construct a density sensitivity function database; The step of inputting the first density value and the second density value into the cost function model, so that the cost function model corrects the formation true density value and the gap in the target density response calculation formula containing the target radial density sensitivity function, comprises the following steps: inputting the first density value and the second density value into the cost function model, determining the iteration step by using the L-M method, determining the minimum value of the absolute value of the cost function, and judging the size relationship between the minimum value and the target threshold value; if the minimum value is less than the target threshold value, outputting the formation true density value and the gap value; if the minimum value is greater than and / or equal to the target threshold value, correcting the formation true density value and the gap value until the minimum value is less than the target threshold value.

2. The method of claim 1, wherein, Before the step of inputting the detector density energy window count data corresponding to the target depth point in the target well into the density calculation formula for characterizing the first density value generated by the standard calibration well calibration of the while-drilling azimuthal density instrument at different densities, the method further comprises the following steps: calibrating the while-drilling azimuthal density instrument in the standard calibration well at different densities, and constructing the density calculation formula of the first density value measured by the detector.

3. The method of claim 1, wherein, Before the step of adding the radial density sensitivity function to the density response calculation formula, the method further comprises the following steps: constructing the radial density sensitivity function based on the gap value between the while-drilling azimuthal density instrument and the well wall of the target well, the gamma ray flux corresponding to the gap value, the detector density energy window count data corresponding to the reference formation density value, and the importance function.

4. The method of claim 1 to 3, wherein, Before inputting the first density value and the second density value into the cost function model, further comprising: constructing the cost function model by using a target weight, an L2 norm of a difference between the first density value and the second density value, a regularization parameter, a formation true density value, a gap, and a borehole fluid density.

5. A while-drilling azimuthal density gap correction device, characterized in that, Comprising: a first density determination module configured to input detector density window count data corresponding to a target depth point in a target well into a density calculation formula for representing a first density value generated by a standard calibration well calibration of a different density of a while-drilling azimuthal density instrument, so as to output a first density value of different detectors; a second density determination module configured to determine a corresponding target radial density sensitivity function from a density sensitivity function database based on the first density value, and acquire a second density value of the target well actually measured by the detector; a density gap determination module configured to input the first density value and the second density value into a cost function model, so that the cost function model corrects a formation true density value and a gap in a target density response calculation formula containing the target radial density sensitivity function, and outputs a corrected target gap and target density value; the while-drilling azimuthal density gap correction device is further configured to add the radial density sensitivity function to the density response calculation formula, so as to construct a target density response calculation formula containing a reference formation density value, a mud density value, a formation true density value, and the radial density sensitivity function; wherein the density response calculation formula is: ； wherein, is a first density value measured as a far and / or near gamma detector, in g / cm 3 ; is a reference base layer density value, is a mud density value, is a formation true density value, in g / cm 3 ; r is a clearance value between the while drilling azimuthal density instrument and the wellbore of the target well, in cm; is a constant coefficient, is a radial density sensitivity function; the while-drilling azimuthal density gap correction device is further configured to construct a sensitivity function simulation model according to a structural parameter of the while-drilling azimuthal density instrument, so as to simulate a radial density sensitivity function and an instrument response characteristic under different reference formation density conditions by using the sensitivity function simulation model, so as to construct a density sensitivity function database; the density gap determination module is specifically configured to input the first density value and the second density value into the cost function model, determine an iteration step by using an L-M method, determine a minimum value of an absolute value of a cost function, and judge a size relationship between the minimum value and a target threshold value; if the minimum value is less than the target threshold value, output a formation true density value and a gap value; if the minimum value is greater than and / or equal to the target threshold value, correct the formation true density value and the gap value until the minimum value is less than the target threshold value.

6. An electronic device, comprising: Comprising: a memory configured to save a computer program; a processor configured to execute the computer program, so as to implement steps of the while-drilling azimuthal density gap correction method according to any one of claims 1 to 4.

7. A computer readable storage medium characterized by for storing a computer program; wherein the computer program is executed by a processor to implement steps of the while-drilling azimuthal density gap correction method according to any one of claims 1 to 4.

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