Data processing and application method for LWD azimuthal gamma in sliding drilling

Abstract

The application provides a data processing and application method for a while-drilling azimuthal gamma ray in sliding drilling, wherein step one is to perform azimuthal correction on the measured values of two detectors of the while-drilling azimuthal gamma ray according to the change of a tool face angle; step two is to perform fast forward calculation on the while-drilling azimuthal gamma ray in sliding drilling according to a prior formation model; and step three is to perform fast inversion calculation on the distance between a drill bit and a formation interface according to the change of actual while-drilling azimuthal gamma ray measured values. The drilling trajectory is adjusted in real time by comprehensively considering the forward calculation and inversion of the while-drilling azimuthal gamma ray. The algorithm in the application is mainly based on sliding directional drilling, the azimuthal correction method of the while-drilling azimuthal gamma ray logging is simple and easy to understand, the fast forward calculation algorithm of the while-drilling azimuthal gamma ray is an algorithm with a 45° window, which can guide the response of other azimuthal gamma ray logging with different window angles, and the analysis is performed by taking the detector as a target.

Description

Technical Field

[0001] This invention belongs to the field of coal technology and relates to directional drilling monitoring, specifically to a method for data processing and application of azimuth gamma during sliding drilling. Background Technology

[0002] Directional drilling in coal mines is widely used for underground gas extraction and geological exploration. It mainly involves designing the borehole trajectory based on the geological conditions explored in the early stages. Under the guidance of the drilling rig and the survey instrument, the directional drilling rig adjusts the drilling direction and drills along the designed trajectory. In actual drilling, due to the complex geological conditions, it is necessary to continuously open branch holes to explore the top and bottom during the drilling process. It is not possible to adjust the borehole trajectory in real time according to the actual geological conditions.

[0003] During directional drilling, the pilot formation model has certain uncertainties due to factors such as insufficient pre-drilling data or complex geological conditions. Therefore, it is necessary to provide a basis for real-time adjustment of the wellbore trajectory based on real-time logging data to reduce drilling risks, increase the oil layer penetration rate, and maximize the role of geological guidance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a data processing and application method for azimuth gamma during sliding drilling, thereby solving the technical problem that there is currently no mature data processing and application method for sliding directional drilling.

[0005] Because its measurement data has both gamma logging characteristics and azimuth characteristics, the azimuth logging tool can monitor the distance between the drill bit and the formation interface in real time based on the measured data, providing a basis for real-time adjustment of the wellbore trajectory.

[0006] Currently, underground directional drilling in coal mines mainly uses sliding drilling, which is very different from rotary drilling. Therefore, it is necessary to find a method for azimuth correction using azimuth gamma during sliding directional drilling, based on the conditions of sliding drilling.

[0007] The key to achieving rapid analysis of azimuth gamma logging response while drilling lies in determining the relationship between the formation location of the azimuth gamma detector and the detector's detection range.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] A data processing method for azimuth gamma during sliding drilling, wherein the method, in the process of sliding directional drilling in coal mines, includes the following steps:

[0010] Step 1: Based on the change in the tool face angle, perform azimuth correction on the measurements of the two detectors of the drilling azimuth gamma.

[0011] Step 2: Perform rapid forward modeling of the azimuth gamma during sliding drilling based on the prior formation model;

[0012] Step 3: Based on the actual changes in the azimuth gamma measurement values ​​while drilling, quickly invert and calculate the distance between the drill bit and the formation interface.

[0013] This invention also protects a method for applying azimuth gamma while drilling for sliding drilling. This method uses the data processing method for azimuth gamma while drilling for sliding drilling described above, and adjusts the drilling trajectory in real time by combining the forward and inverse results of the azimuth gamma while drilling.

[0014] Compared with the prior art, the present invention has the following technical effects:

[0015] (I) The algorithm in this invention is mainly based on the analysis of sliding directional drilling. The azimuth correction method of azimuth logging while drilling is simple and easy to understand. The fast forward modeling algorithm of azimuth logging while drilling is a 45° windowing algorithm, which can guide the response of azimuth logging with other windowing angles. At the same time, the analysis is performed with the detector as the target. This calculation and analysis method can be used not only for the structure of azimuth logging while drilling tools, but also for azimuth logging tools with detector ring array. When the formation model is known, the formation model can be updated and the wellbore trajectory adjusted by comparing the forward model and the actual azimuth logging curves.

[0016] (II) The calculation formula for the distance between the detector and the formation interface in this invention can guide the adjustment of the drilling trajectory in real time. Based on the actual changes in the azimuth gamma logging curve, the drilling trajectory can be understood even without a prior formation model, and then the drilling trajectory can be adjusted in a timely manner as needed.

[0017] (III) None of the formulas involved in this invention involve multiple loops, and the calculation speed is fast. They are suitable for real-time drilling guidance. These algorithms are applicable to high-configuration computers on the ground as well as low-configuration explosion-proof computers in coal mines. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the azimuth logging tool used in this invention.

[0019] Figure 2 This is a schematic diagram of the detection range of the two detectors in this invention.

[0020] Figure 3 This is a schematic diagram showing the division of the upper and lower gamma detection areas in the azimuth logging tool during drilling in this invention (the count in area A is the upper gamma and the count in area B is the lower gamma).

[0021] Figure 4A flowchart for azimuth correction of gamma detector measurements during drilling.

[0022] Figure 5 This is the horizontal layered model of the fast forward modeling algorithm for azimuth gamma logging response in this invention.

[0023] Figure 6 This is a schematic diagram of the detection when the detector has a uniform detection range in this invention.

[0024] Figure 7 This is a schematic diagram of the detection when the detector's detection range intersects with the geological interface in this invention.

[0025] Figure 8 A flowchart for calculating the azimuth gamma response using drilling azimuth forward modeling.

[0026] Figure 9 This is a schematic diagram of a formation model used in this invention to study the variation of azimuth gamma during drilling in formations with different radioactivity.

[0027] Figure 10 In this invention Figure 7 The changes in the azimuth curve throughout the entire drilling process.

[0028] Figures 11(a) to 11(d) This is a schematic diagram illustrating the relationship between the angle between the azimuth gamma ray logging tool and the formation, the formation dip angle, and the direction of the azimuth gamma ray logging tool penetrating the formation in this invention. In Figure 11(a), the formation dips upwards and the azimuth gamma ray logging tool penetrates the target formation upwards; in Figure 11(b), the formation dips upwards and the azimuth gamma ray logging tool penetrates the target formation downwards; in Figure 11(c), the formation dips downwards and the azimuth gamma ray logging tool penetrates the target formation upwards; and in Figure 11(d), the formation dips downwards and the azimuth gamma ray logging tool penetrates the target formation downwards.

[0029] Figure 12 This is a schematic diagram of the relationship between detector 1 and the interface when the strata dip down and the detector 1 passes through the coal seam to the roof in this invention (the red area represents the detection range of detector 1, and the green area represents the detection range of detector 2).

[0030] Figure 13 This is a schematic diagram of the relationship between detector 2 and the interface when the strata dip down and the detector 2 passes through the coal seam to the roof in this invention (the red area represents the detection range of detector 1, and the green area represents the detection range of detector 2).

[0031] Figure 14 This is a schematic diagram of the relationship between detector 1 and the interface when the stratum dips upward and the detector 1 passes through the coal seam to the roof in this invention (the red area represents the detection range of detector 1, and the green area represents the detection range of detector 2).

[0032] Figure 15This is a schematic diagram of the relationship between detector 2 and the interface when the stratum dips upward and the detector 2 passes through the coal seam to the roof in this invention (the red area represents the detection range of detector 1, and the green area represents the detection range of detector 2).

[0033] Figure 16 This is a schematic diagram of the relationship between detector 2 and the interface when the strata dip down and the detector 2 penetrates from the roof into the coal seam in this invention (the red area represents the detection range of detector 1, and the green area represents the detection range of detector 2).

[0034] Figure 17 This is a schematic diagram of the relationship between detector 1 and the interface when the strata dip down and penetrate from the roof into the coal seam in this invention (the red area represents the detection range of detector 1, and the green area represents the detection range of detector 2).

[0035] Figure 18 This is a schematic diagram of the relationship between detector 2 and the interface when the stratum dips upward and penetrates from the roof into the coal seam in this invention (the red area represents the detection range of detector 1, and the green area represents the detection range of detector 2).

[0036] Figure 19 This is a schematic diagram of the relationship between detector 1 and the interface when the stratum dips upward and penetrates from the roof into the coal seam in this invention (the red area represents the detection range of detector 1, and the green area represents the detection range of detector 2).

[0037] Figures 20(a) and 20(b) show the relationship between the drill bit and the formation in this invention. Figure 20(a) shows the relationship between the drill bit and the formation when the formation dips downwards, and Figure 20(b) shows the relationship between the drill bit and the formation when the formation dips upwards.

[0038] Figure 21 This is a flowchart for the inversion analysis of real-time measurement data from azimuth gamma logging while drilling.

[0039] Figures 22(a) and 22(b) are flowcharts of the practical application of the present invention in sliding directional drilling. Figure 22(a) is a flowchart of the application of the present invention in sliding directional drilling without a prior formation model, and Figure 22(b) is a flowchart of the application of the present invention in sliding directional drilling with a prior formation model.

[0040] Figure 23 This is a schematic diagram of the formation model for the practical application of the azimuth gamma logging of the present invention.

[0041] Figure 24 This is a graph showing the variation of upper and lower gamma ray in the actual application of the azimuth logging of the present invention.

[0042] Figure 25This is a diagram showing the drilling state and the distance between the natural gamma detector and the formation interface, inverted in the practical application of the azimuth gamma logging of the present invention.

[0043] Figures 12 to 18 In the diagram, the red area represents the area with a relatively dark color, and the green area represents the area with a relatively light color.

[0044] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0045] The purpose of this invention is to provide a method for processing and applying azimuth gamma data while drilling in sliding directional drilling. This method mainly includes an azimuth correction method for real-time azimuth gamma logging during sliding directional drilling, a forward modeling method for azimuth gamma logging during sliding drilling, a method for rapid inversion analysis of real-time azimuth gamma logging during sliding drilling, and a method for real-time calculation of the drill bit distance from the formation interface. The method for rapid inversion analysis of azimuth gamma logging based on the forward modeling method can improve computational speed and enhance automated management. The method for real-time calculation of the drill bit distance from the formation interface can support timely adjustment of the wellbore trajectory, provide technical support for sliding directional drilling, improve drilling efficiency, reduce drilling risks, and fully leverage the geological guidance role of azimuth gamma logging while drilling.

[0046] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0047] Example:

[0048] This embodiment provides a data processing method for azimuth gamma logging while drilling (WABG) for sliding directional drilling. The method includes a WEBG azimuth gamma logging tool for downhole sliding directional drilling in coal mines. The WEBG azimuth gamma logging tool has two gamma detectors, namely detector 1 and detector 2, arranged in a front-to-back configuration. The WEBG azimuth gamma logging tool has a window size of 45°, and the two windows are arranged symmetrically at 180°. The upper gamma face angle Φ is defined as the tool face angle of the WEBG azimuth gamma logging tool. An upper gamma face angle of 0° indicates that the tool face angle of the WEBG azimuth gamma logging tool is when the center of detector 1 is facing upwards. The measurement range of the upper gamma face angle is 0° to 360°.

[0049] A schematic diagram of the structure of the azimuth logging-while-drilling tool is shown below. Figure 1 As shown, the detection ranges of the two detectors are as follows: Figure 2 As shown, during sliding drilling, the azimuth logging tool does not count by sector, but by upper and lower gamma ray counts. The upper and lower gamma ray ranges are as follows: Figure 3 As shown.

[0050] The azimuth logging tool is installed inside the drill pipe. During directional drilling (sliding drilling), the tool face angle of the azimuth logging tool changes as the tool face angle of the drill string is adjusted.

[0051] Specifically, this method, in the process of sliding directional drilling in coal mines, includes the following steps:

[0052] Step 1: Based on the change in the tool face angle, perform azimuth correction on the measurements of the two detectors of the drilling azimuth gamma.

[0053] In step one, the method for azimuth correction is as follows:

[0054] During sliding drilling, the detector's detection area also changes, dividing the entire detection area into two parts, such as... Figure 3 As shown, Figure 3 The middle arrow represents the upper gamma facing angle Φ. The detection count in area A is defined as the upper gamma, and the count in area B is defined as the lower gamma. Based on the change of the upper gamma facing angle and the detection areas of the two detectors, the azimuth correction formula for the azimuth gamma can be obtained.

[0055] Based on the relationship between the change in the upper gamma angle and the detection areas of the two detectors, the azimuth correction formula for the measurements of the two detectors during drilling azimuth gamma can be obtained:

[0056] When Φ∈[0°,67.5°]∪(292.5°,360°]:

[0057] When Φ∈(112.5°,247.5°]:

[0058] When Φ∈(67.5°,112.5°]:

[0059] When Φ∈(247.5°,292.5°]:

[0060] In the formula:

[0061] Φ is the upper gamma angle, in degrees.

[0062] GR 上 Upper gamma, unit: API;

[0063] GR 下 Lower gamma, unit: API;

[0064] GR1 is the measurement value of detector 1, in API.

[0065] GR2 is the measurement value of detector 2, in API.

[0066] Azimuth correction of azimuth gamma measurement data during sliding directional drilling is performed based on the change in the upper gamma face angle of the azimuth gamma measurement data. The correction formula is as described above, and the specific implementation process is as follows: Figure 4 As shown.

[0067] Step 2: Perform rapid forward modeling of the azimuth gamma during sliding drilling based on the prior formation model;

[0068] To achieve rapid forward modeling of azimuth gamma while drilling, it is necessary to analyze the response characteristics of azimuth gamma while drilling for directional sliding drilling. Currently, the forward modeling calculation of azimuth gamma while drilling is performed using Monte Carlo simulation, which is slow. New methods are needed to analyze the response of azimuth gamma. The new response equation of azimuth gamma can also be used in actual drilling to perform forward modeling based on the prior formation model and the well trajectory during actual drilling. The results can be compared with the actual measurement results of azimuth gamma while drilling to provide a basis for adjusting the formation model.

[0069] Assume the stratigraphic model is as follows Figure 5 The image shows horizontal layers. Figure 5 The shaded sector represents the detection range of the gamma detector, with the detector at the center. Figure 5 The position of point O in the middle.

[0070] Figure 5 The model satisfies the following conditions: (1) The formation is a horizontally layered homogeneous medium (for irregular non-horizontal formations, it is only necessary to consider them in sections during analysis); (2) The wellbore has no obvious enlargement. Given the low maturity of the mud cake in the logging while drilling, the influence of the wellbore and mud cake is ignored; (3) The counting tube in the detector is located at the center of the azimuth gamma logging tool while drilling, with an azimuth and a window angle of 45°; (4) The radioactivity intensity in the formation is equivalent intensity; (5) The upper gamma face angle of the azimuth gamma logging tool while drilling is 0°.

[0071] In step two, the method for fast forward modeling is as follows:

[0072] Based on the prior formation model, the dip angle and azimuth parameters of the wellbore trajectory are measured in real time, as well as the toolface angle of the azimuth gamma ray logging tool. The detection areas of the two detectors at the current point are determined based on the size of the toolface and the current borehole trajectory position. The relationship between the detection range of the two detectors at the current point and the formation interface of the prior formation model is then determined. If the detector's detection range is only within one formation, the forward modeling value of the gamma response of the azimuth gamma ray logger is calculated according to the response formula for azimuth gamma ray loggers without adjacent formation influence. If the detector's detection range includes two formations, the forward modeling value of the gamma response of the azimuth gamma ray logger is calculated according to the response formula for azimuth gamma ray loggers with adjacent formation influence. The specific implementation flowchart is as follows: Figure 8 As shown.

[0073] Preferably, in step two, the response formula for the fast forward modeling of azimuth gamma during drilling is calculated using a 45° window. This calculation method is also applicable to the response of azimuth gamma at other window angles. Since sliding directional drilling in the coal industry is mainly used for drilling along coal seams, the minimum coal seam thickness is 0.5m, while the maximum detection radius of the gamma detector is 0.4m. Therefore, we only consider the case where the detector detects only two different strata, and do not consider the case where the detection range spans three layers at the same time, i.e., the coal seam thickness is less than 0.4m. When the contributing area is two strata, the detection area is decomposed according to the relationship between the detector's detection range and the strata, and the gamma ray flux of each area is calculated separately. Then, the values ​​of each area are added together to obtain the total gamma ray flux value.

[0074] Based on the detector's detection range and distance from the geological interface, there are two cases: (1) The detector is located in a certain stratum, and its detection range is not affected by the adjacent strata. The detection range is as follows: Figure 6 As shown; (2) The detector is located in a certain stratum, and the detection range is affected by the adjacent strata, such as Figure 7 As shown.

[0075] In a further preferred embodiment, in step two, such as Figure 6 As shown, if the detector's detection range is not affected by adjacent layers, the gamma-ray flux above or below point O of the detector can be calculated using the formula for homogeneous formations:

[0076]

[0077] In the formula:

[0078] J ro This represents the gamma-ray flux at point O of the detector when the detector is not affected by adjacent layers;

[0079] r0 is the detector's detection radius, in cm;

[0080] ρ is the formation density, in g / cm³. 3 ;

[0081] q represents the content of radioactive material in the strata, in g / g;

[0082] The average radiation intensity of gamma rays from radioactive materials in the α-strata, in units of gamma photons / g·s;

[0083] μ is the absorption coefficient of the formation, in cm. -1 ;

[0084] r is the distance between a spatial point in OXYZ spherical coordinates and the origin of the spherical coordinates;

[0085] θ is the angle between the line connecting the spatial point and the origin of the spherical coordinates in OXYZ and the Z-axis;

[0086] is the angle between the projection line of the line connecting the spatial point and the coordinate origin in the OXY plane and the X-axis in the OXYZ spherical coordinates;

[0087] As Figure 7 shown, if the detection range of the detector is affected by adjacent layers, it can be calculated by dividing different contribution regions. Since the sliding directional drilling in the coal field is mainly used for drilling along the coal seam, the minimum mining thickness of the coal seam is 0.5 m, and the maximum detection radius of the gamma detector is 0.4 m, so only the case where the detector only detects 2 different strata is considered, and the case where the detection range simultaneously crosses 3 layers (coal seam thickness less than 0.4 m) is not considered. When the contribution region is two strata ( Figure 7 ), the bow-shaped body ( Figure 7 Area A in Figure 7 ) and the cone (

[0088] Area B in

[0089] ) are integrated, and then the gamma-ray flux values of each region are added to obtain the total value. Figure 7 When h < r0·cos(π / 8), as

[0090]

[0091]

[0092] J = J A + J B ;

[0093] In the formula:

[0094] J A and J B are the gamma-ray fluxes at the detector O point in the bow-shaped body area A and the cone area B, respectively;

[0095] δ is half of the radian of the bow-shaped area, unit: radian, δ = ACOS(h / r0);

[0096] r1 is the generatrix of the cone, unit: cm, r1 = h;

[0097] h is the distance between the detector and the formation interface, unit: cm;

[0098] r0 is the detection radius of the detector, unit: cm;

[0099] ρ1 and ρ2 are the formation densities of formation 1 and formation 2 respectively, unit: g / cm 3 ;

[0100] q1 and q2 are the contents of radioactive substances in formation 1 and formation 2 respectively, unit: g / g;

[0101] α1 and α2 are the average radiation intensities of gamma rays of radioactive substances in formation 1 and formation 2 respectively, unit: gamma photons / g·s;

[0102] μ1 and μ2 are the absorption coefficients of formation 1 and formation 2 respectively, unit: cm -1 ;

[0103] When r0·cos(π / 8) < h < r0, as shown in the left figure below, the detection area is divided into three parts: the bow-shaped area A, the conical area B1, and the fan-shaped area C. The calculation formulas for the gamma-ray fluxes at the detector O point in each area are as follows: Figure 7 The gamma-ray fluxes at the detector O point in each area are as follows:

[0104]

[0105]

[0106] <​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​q1 and q2 represent the radioactive material content in stratum 1 and stratum 2, respectively, in g / g.

[0116] α1 and α2 are the average radiation intensities of gamma rays from radioactive materials in strata 1 and strata 2, respectively, in gamma photons / g·s;

[0117] μ1 and μ2 are the absorption coefficients of formation 1 and formation 2, respectively, in cm. -1 .

[0118] Step 3: Based on the actual changes in the azimuth gamma measurement values ​​while drilling, quickly invert and calculate the distance between the drill bit and the formation interface.

[0119] In step three, the method for quickly inverting and calculating the distance between the drill bit and the formation interface is as follows:

[0120] Based on the differences and rates of change between the upper and lower gamma values ​​measured in real-time during drilling, the system analyzes whether the azimuth gamma detector has detected the formation boundary during drilling. When the measured upper and lower gamma values ​​separate, the rates of change of the upper and lower gamma values ​​are calculated. The drilling direction is determined based on the sign of the rate, and the relative magnitude of the rates is used to determine whether the upper or lower gamma changes first. Finally, the distance between the detector and the formation interface is calculated by combining the formation dip and the upper gamma face angle. The specific implementation process is as follows: Figure 21 As shown.

[0121] Adjusting the drilling trajectory according to the distance can guide the drilling process.

[0122] In coal mining, sliding directional drilling monitoring can analyze the relationship between the wellbore trajectory and the formation interface based on the response curve characteristics of real-time azimuth gamma logging, thereby adjusting the wellbore trajectory in real time and improving drilling efficiency.

[0123] During sliding directional drilling, when the azimuth gamma ray while drilling (AWD) moves from a low-radioactivity stratum (coal seam) to a high-radioactivity stratum (mudstone layer), and vice versa, according to the theoretical formula for azimuth gamma response, without considering changes in the tool face angle or the dip and dip angle of the formation, the upper gamma tool face angle remains unchanged at 0°. Initially, the detector is positioned in the middle of the coal seam, 1.5m from the formation interface. The drilling trajectory proceeds at an angle of 0.5°, with a borehole length of approximately 750m and a sampling interval of 3m. The coal seam is a low-radioactivity stratum with a radioactivity level of 20 API, while the mudstone layer is a high-radioactivity stratum with a radioactivity level of 80 API. The changes in the azimuth gamma response curve while drilling are analyzed, and the simulated azimuth gamma detector drilling trajectory is shown below. Figure 9 As shown, Figure 9 The mudstone layer above the coal seam is called the roof, and the mudstone layer below the coal seam is called the floor. The variation of the gamma ray curve with drilling azimuth is as follows: Figure 10 As shown.

[0124] Preferably, in step three, the specific method for quickly inverting and calculating the distance between the drill bit and the formation interface is as follows:

[0125] Step S31: When the drill bit is drilling in the target layer and the distance between the azimuth gamma logging tool and the formation interface is much greater than the detection range of the azimuth gamma detector, the upper and lower azimuth natural gamma curves coincide.

[0126] Step S32: When the drill bit penetrates from the low radioactive strata to the high radioactive surrounding rock, the upper gamma count increases first, followed by the lower gamma count. The upper gamma count is larger than the lower gamma count, and the rate of increase of the upper gamma count is faster than that of the lower gamma count. This indicates that the drill bit is drilling in the upper direction and may need to drill out of the reservoir from the upper direction. At this time, the drill bit direction should be adjusted in time to make it drill in the lower direction.

[0127] Step S33: When the drill bit drills from the high radioactive stratum of the upper surrounding rock to the low radioactive target layer, the lower gamma decreases first, and the upper gamma decreases later. The upper gamma is larger than the lower gamma, and the rate of decrease of the lower gamma is faster than that of the upper gamma. The azimuth logging tool penetrates from the roof into the coal seam.

[0128] Step S34: When the drill bit drills from the low radioactivity stratum to the high radioactivity surrounding rock, the lower gamma increases first, and the upper gamma increases later. The lower gamma is larger than the upper gamma, and the rate of increase of the lower gamma is faster than that of the upper gamma. The azimuth logging tool penetrates from the coal seam to the bottom plate.

[0129] Step S35: When the drill bit drills from the high-radioactivity surrounding rock to the low-radioactivity target layer, the upper gamma decreases first, followed by the lower gamma, and the lower gamma is larger than the upper gamma. The rate at which the upper gamma decreases is faster than the rate at which the lower gamma decreases. The azimuth logging tool travels from the bottom plate into the coal seam.

[0130] Specifically, in this embodiment, the method for rapidly inverting and calculating the distance between the drill bit and the formation interface is as follows:

[0131] Step S31, in Figure 9 Before position 1, the drill bit drills into the reservoir, and the natural gamma curves of the upper and lower positions coincide;

[0132] Step S32, the drill bit drills to... Figure 7 At position 1, the upper gamma count increases first, followed by the lower gamma count. The upper gamma count is naturally larger than the lower gamma count, and the rate of increase in the upper gamma count is faster than that in the lower gamma count. This indicates that the drill bit is drilling in an upward direction, possibly intending to drill through the reservoir from that direction. In this case, the drill bit direction should be adjusted promptly to drill downwards. Figure 9When the reference number is 2, the upper and lower gamma rays coincide, and the drilling azimuth gamma logging tool enters the top plate;

[0133] Step S33, the drill bit reaches... Figure 9 At position 3, the lower gamma ray decreases first, followed by the upper gamma ray, with the upper gamma ray being larger than the lower gamma ray. The rate of decrease in the lower gamma ray is faster than that of the upper gamma ray. The azimuth logging tool penetrates from the roof into the coal seam; reaching... Figure 9 At position 4, the upper and lower gamma rays overlap again, returning to the coal seam;

[0134] Step S34, the drill bit reaches... Figure 9 At position 5, the lower gamma ray increases first, followed by the upper gamma ray, with the lower gamma ray being larger than the upper gamma ray. The rate of increase of the lower gamma ray is faster than that of the upper gamma ray. The azimuth logging tool penetrates from the coal seam towards the floor. Figure 9 At position 6, the upper and lower gamma ray logs overlapped again, and the azimuth gamma ray logging tool was fully inserted into the bottom plate.

[0135] Step S35, the drill bit reaches... Figure 9 At position 9, the upper gamma ray decreases first, followed by the lower gamma ray, with the lower gamma ray being larger than the upper gamma ray. The upper gamma ray decreases at a faster rate than the lower gamma ray. The azimuth logging tool penetrates from the bottom plate into the coal seam; reaching... Figure 9 At position 8, the upper and lower gamma rays overlapped again, and the azimuth gamma logging tool returned to the coal seam.

[0136] In a further preferred embodiment, in step three, when the azimuth gamma logging tool drills through different radioactive formations, the distance between the drill bit and the formation interface is calculated from the distance between the azimuth gamma detector and the formation interface.

[0137] When the detector is located at different positions relative to the top and bottom of the coal seam, the upper and lower azimuth gamma curves exhibit different shapes. Under the condition that the radioactivity of the high and low radioactive layers is uniform and constant, the amplitude difference between the upper and lower gamma curves, except for the overlapping segments, corresponds one-to-one with the detector's position, and there is no ambiguity. Therefore, the different combinations of upper and lower azimuth gamma curves can be used to determine the location of the drilling azimuth gamma logging tool within the formation.

[0138] The response of azimuth gamma ray logging while drilling (WAWL) is related to the dip direction and dip angle of the formation, the toolface angle of the WAWL tool, and the direction of penetration from the target layer into the surrounding rock. When the formation dip and penetration direction differ, the changes in upper and lower gamma rays, as well as the methods for calculating the distance between the drill bit and the target layer boundary, are all different. The influence of formation dip and penetration direction on the dip angle of the WAWL tool and the angle between the WAWL tool and the formation is as follows: Figures 11(a) to 11(d) As shown.

[0139] More preferably, in step three, the response of the azimuth gamma while drilling is related to the dip direction and dip angle of the formation, the tool face angle of the azimuth gamma logging tool while drilling, and the direction of penetration from the target layer into the surrounding rock. Therefore, determining the distance between the detector and the formation interface based on the change of the azimuth gamma measurement value while drilling requires comprehensive consideration of the dip direction, dip angle, and upper gamma face angle of the formation.

[0140] The specific method for calculating the distance between the drill bit and the formation interface is as follows:

[0141] Step a, when the formation dips and the azimuth logging tool penetrates from the low-radioactivity target coal seam into the high-radioactivity surrounding mudstone layer, and when the reading of detector 1 is high gamma, and Φ is different, and detector 1 can detect the interface, the relationship between the detector range and the interface is as follows: Figure 12 As shown.

[0142] When detector 1 detects the upper interface, detector 2 cannot detect the upper interface, and a separation occurs between the upper and lower gamma rays. D is the detection radius of the detector, and H1 is the distance between detector 1 and the formation, as shown in the following formula:

[0143]

[0144] To facilitate the display of the relationship between the upper gamma plane angle and the dip angle of the formation, the formulas are expressed in degrees.

[0145] Step b: When the ground dips and the azimuth logging tool penetrates from the low-radioactivity target coal seam into the high-radioactivity surrounding mudstone layer, and when the detector 2 reading is upper gamma, Φ is different, and the lower detector can detect the interface, the relationship between the detection range and the interface is as follows: Figure 13 As shown.

[0146] The distance H2 between detector 2 and the ground is shown in the following formula:

[0147]

[0148] Step c, when the updip, azimuth-based logging tool penetrates from the low-radioactivity target coal seam into the high-radioactivity surrounding mudstone layer, and when the reading of detector 1 is the upper gamma, and Φ is different, when detector 1 can detect the interface, the relationship between the detection range and the interface is as follows: Figure 14 As shown. Detector 2 cannot detect the upper interface; a separation occurs between the upper and lower gamma rays. D is the detection radius of the detector, and H1 is the distance H1 between detector 1 and the formation, as shown in the following formula:

[0149]

[0150] Step d: When the updip, azimuth-based logging tool penetrates from the low-radioactivity target coal seam into the high-radioactivity surrounding mudstone layer, and when the detector 2 reading is high gamma, and Φ is different, and detector 2 can detect the interface, the relationship between the detection range and the interface is as follows: Figure 15 As shown, the distance H2 between detector 2 and the ground is given by the following formula:

[0151]

[0152] When the azimuth logging tool penetrates from the upper surrounding mudstone layer into the coal, the lower gamma changes first: when Φ is different, the relationship between the detection range of the azimuth gamma detector and the formation is also different. Similar to the above analysis method, first consider the dip of the formation, then consider the upper gamma face angle, and then analyze the relationship between the detection range and the formation interface with the detector as the target.

[0153] When penetrating from the upper surrounding mudstone layer into the target coal seam, the lower gamma changes first, and a separation occurs between the lower and upper gamma.

[0154] Step e: When the formation dips and the logging-while-drilling azimuth gamma ray tool penetrates from the upper surrounding mudstone layer into the coal seam, and when the detector 2 reading is at the lower gamma ray level, the relationship between the detector's detection range and the formation is as follows when the upper gamma ray face angle is different: Figure 16 As shown, the distance H2 between detector 2 and the ground is given by the following formula:

[0155]

[0156] Step f: When the formation dips and the logging-while-drilling azimuth gamma ray tool penetrates from the upper surrounding mudstone layer into the coal seam, and when the detector 1 reading is lower gamma and the upper gamma face angle is different, the relationship between the logging-while-drilling azimuth gamma ray tool's detection range and the formation is as follows: Figure 17 As shown, the distance H1 between detector 1 and the ground is given by the following formula:

[0157]

[0158] Step g, when the formation dips upwards, and the azimuth logging-while-drilling tool penetrates from the upper surrounding mudstone layer into the coal seam, and when the detector 2 reading is lower gamma, the relationship between the detector's detection range and the formation is as follows: Figure 18 As shown, the distance H2 between detector 2 and the ground is given by the following formula:

[0159]

[0160] Step h, when the formation dips upwards, and the azimuth logging-while-drilling tool penetrates from the upper surrounding mudstone layer into the coal seam, and when detector 1 reads a lower gamma, the relationship between the detector's detection range and the formation is as follows: Figure 19As shown, the distance H1 between detector 1 and the ground is given by the following formula:

[0161]

[0162] In the formulas for steps a to h:

[0163] Φ is the upper gamma angle, in degrees.

[0164] β is the dip angle of the formation, in degrees.

[0165] D represents the detection radius of the azimuth logging-while-drilling tool, in cm.

[0166] Step i, Distance between drill bit and formation interface: When the azimuth logging-while-drilling tool penetrates from the coal seam to the roof, the relationship between the drill bit and the formation is shown in Figures 20(a) and 20(b) based on the vertical distance of the detector from the formation. Calculate the distance L of the drill bit from the formation interface along the drilling direction and the distance H of the drill bit perpendicular to the interface. bit As shown in the following formula:

[0167]

[0168] H bit =H-sinα*L tb

[0169] In the formula:

[0170] H is the vertical distance between the detector and the stratum analyzed above, H = H1 or H = H2;

[0171] α is the angle between the azimuth logging tool and the formation, in degrees.

[0172] L tb Let L be the distance from the detector to the drill bit. tb1 The distance from detector 2 to the drill bit is Ltb2 L tb =L tb1 or L tb =L tb2 , Unit: cm.

[0173] Example 2:

[0174] This embodiment provides an application method for azimuth gamma while drilling in sliding drilling. This method adopts the data processing method for azimuth gamma while drilling in sliding drilling in Embodiment 1, and adjusts the drilling trajectory in real time by combining the forward and inverse results of azimuth gamma while drilling.

[0175] Specifically, the process of applying each algorithm in Example 1 to sliding directional drilling is shown in Figure 22.

[0176] When geological data is insufficient to establish a good formation model, the measured curve characteristics of azimuth gamma while drilling are used to analyze the relationship between the wellbore trajectory and the formation interface. The wellbore trajectory is adjusted in real time as needed to make it drill along the target layer. The application flowchart of azimuth gamma while drilling is shown in Figure 22(a). Before drilling, when geological data is sufficient, the formation model and wellbore trajectory are adjusted by combining forward and inverse azimuth gamma while drilling. The application flowchart is shown in Figure 22(b).

[0177] Figure 22 is a flowchart of the present invention used in actual sliding directional drilling. In practical applications, the actual drilling trajectory is adjusted according to this flowchart to guide drilling. The specific implementation process is as follows:

[0178] When the formation model information is incomplete, the azimuth correction of the azimuth gamma measurement is performed in real time based on the drilling azimuth gamma measurement value. Then, data processing and analysis are performed to analyze the changes in the shape of the azimuth gamma curve and calculate the distance of the detector from the top and bottom plates, thereby adjusting the drilling trajectory. When there is a lot of preliminary exploration data and relatively complete formation information, a formation model is preset. Based on the data analysis of the real-time drilling azimuth gamma measurement and combined with the method of rapid forward modeling of drilling azimuth gamma, the drilling trajectory is monitored comprehensively. The azimuth gamma value obtained by the rapid forward modeling of drilling azimuth gamma is compared with the actual measured azimuth gamma to see if they are consistent. If the difference exceeds the normal fluctuation range, it is considered that the actual formation is more complex than the preset formation, and the formation model and wellbore trajectory need to be adjusted.

[0179] Referring to the flowcharts in Figures 22(a) and 22(b), the specific implementation process of applying real-time azimuth gamma to adjust the borehole trajectory is as follows:

[0180] Drilling for gas extraction along coal seams in underground coal mines aims to ensure the borehole penetrates the coal seam without entering the surrounding rock. Preliminary exploration has provided a basic indication of the coal seam's strike. The distribution of the coal seam and surrounding rock is complex. The overlying strata of the coal seam are mudstone, while the underlying strata are argillaceous limestone. The average natural gamma ray density (NGR) in the coal seam is 20 API, the average NGR in the overlying mudstone is 80 API, and the average NGR in the underlying limestone is 60 API. The relationship between the coal seam and surrounding rock for the planned drilling hole is shown in the diagram below. Figure 23 As shown, the changes in upper and lower gamma are as follows: Figure 24 As shown, the inverted detector distance to the interface and drilling indication are as follows: Figure 25 As shown. The entire drilling process, which utilizes azimuth gamma adjustment to adjust the drilling trajectory, is illustrated below:

[0181] (1) A hole is drilled in the coal seam with an inclination angle of 1.5°. The natural gamma detector is 4m away from the drill bit. When drilling in the coal seam, the upper and lower gamma values ​​are the same, both indicating that the drill is in the coal seam. The gamma value is 20 API. At this time, the drilling indicator is 0, and the distance between the detector and the interface is not displayed, indicating that the drill is in the coal seam and the interface has not been detected.

[0182] (2) When the drill bit is about to enter the roof, the upper gamma increases first and the lower gamma increases later. At this time, the drilling indicator is 0.4, indicating that it is passing through the interface between the coal seam and the overlying rock strata. The distance between the detector and the interface varies from 0 to 0.4.

[0183] (3) When both the upper and lower gamma reach 80 API, the drilling indicator is 0.8 and the distance between the detector and the interface is not displayed, indicating that it has entered the overlying rock layer. The detector indicates that the natural gamma detector has entered the overlying mudstone layer from point A. At this time, adjust the drill bit to make the drilling angle downward and return to the coal seam.

[0184] (4) During the process of the drill bit returning to the coal seam, the lower gamma first decreases and the upper gamma then decreases. At this time, the drilling indicator is 0.4, indicating that the layer is being penetrated. The distance between the detector and the interface varies from 0 to 0.4.

[0185] (5) When the upper gamma and lower gamma reach 20 API, the drilling indication is 0, the distance between the detector and the interface is not displayed, and the natural gamma detector enters the coal seam from point B.

[0186] (6) Continue drilling. The gamma light increases first, and then increases again. At this time, the drilling indicator is -0.4, indicating that it is penetrating the interface between the coal seam and the underlying strata. The distance between the detector and the interface varies from 0 to -0.4.

[0187] (7) When the upper gamma and lower gamma reach 65 API, the drilling indicator is -0.8 and the distance between the detector and the interface is not displayed. This indicates that the natural gamma detector has entered the lower argillaceous limestone from point C. At this time, the drill bit should be adjusted so that its drilling inclination is upward and it returns to the coal seam.

[0188] (8) The upper gamma decreases first, and the lower gamma decreases later. At this time, the drilling indicator is -0.4, indicating that it is at the interface between the stratum and the coal seam below. The distance between the detector and the interface varies from 0 to -0.4.

[0189] (9) When the upper gamma and lower gamma reach 20 API, the drilling indication is 0 and the distance between the detector and the interface is not displayed, indicating that the detector has completely entered the coal seam.

[0190] (10) Thus, according to the process from (1) to (9), the drill bit is continuously adjusted according to the changes in the upper gamma, lower gamma and the inverted drilling state and vertical distance to ensure drilling in the coal seam.

Claims

1. A data processing method for azimuth gamma during sliding drilling, characterized in that, This method, applied during underground sliding directional drilling in coal mines, includes the following steps: Step 1: Based on the change in the tool face angle, perform azimuth correction on the measurements of the two detectors of the drilling azimuth gamma. In step one, the method for azimuth correction is as follows: Based on the relationship between the change in the upper gamma angle and the detection areas of the two detectors, the azimuth correction formula for the measurements of the two detectors during drilling azimuth gamma can be obtained: ； ； ； ； In the formula: Φ is the upper gamma angle, in degrees. GR 上 Upper gamma, unit: API; GR 下 Lower gamma, unit: API; GR1 is the measurement value of detector 1, in API. GR2 is the measurement value of detector 2, in API. Step 2: Perform rapid forward modeling of the azimuth gamma during sliding drilling based on the prior formation model; In step two, the method for fast forward modeling is as follows: Based on the prior formation model, the dip angle and azimuth parameters of the wellbore trajectory and the toolface angle of the azimuth gamma ray logging tool are measured in real time. The detection areas of the two detectors at the current point are determined based on the size of the toolface and the current borehole trajectory position. The relationship between the detection range of the two detectors at the current point and the formation interface of the prior formation model is then assessed. If the detector's detection range is only within one formation, the forward modeling value of the gamma response of the detector in the azimuth gamma ray logging tool is calculated according to the response formula for azimuth gamma ray logging without the influence of adjacent formations. If the detector's detection range includes two formations, the forward modeling value of the gamma response of the detector in the azimuth gamma ray logging tool is calculated according to the response formula for azimuth gamma ray logging with the influence of adjacent formations. In step two, if the detector's detection range is not affected by adjacent layers, the gamma-ray flux above or below point O of the detector can be calculated using the formula for homogeneous formations: In the formula: J ro This represents the gamma-ray flux at point O of the detector when the detector is not affected by adjacent layers; r 0 represents the detector's detection radius, in cm; ρ Formation density, unit: g / cm³ 3 ; q The content of radioactive materials in the strata, in g / g; α The average radiation intensity of gamma rays from radioactive materials in the strata, in units of gamma photons / g·s; μ The absorption coefficient of the formation, unit: cm -1 ; r The distance between a point in space in OXYZ spherical coordinates and the origin of the spherical coordinate system; θ The angle between the line connecting a spatial point in OXYZ spherical coordinates to the origin of the spherical coordinates and the Z-axis; φ Let X be the angle between the projection of the line connecting a spatial point and the origin in the OXYZ spherical coordinate system onto the OXY plane and the X-axis. If the detector's detection range is affected by adjacent layers, then: when The detector's detection area is divided into an arc-shaped region A and a cone-shaped region B. The formula for calculating the gamma-ray flux at point O of the detector in each region is as follows: ； ； ； In the formula: J A and J B These represent the gamma-ray flux at detector point O for the arc-shaped region A and the cone-shaped region B, respectively. δ It is half the arc of the arc-shaped region, in radians. ; r 1 represents the generatrix of the cone, in cm; r1 = h. h Distance between the detector and the geological interface, in cm; r 0 represents the detector's detection radius, in cm; ρ 1 and ρ 2 represents the formation density of strata 1 and strata 2, respectively, in g / cm³. 3 ; q 1 and q 2 represents the content of radioactive materials in stratum 1 and stratum 2, respectively, in g / g; α 1 and α 2. The average gamma radiation intensity of radioactive materials in strata 1 and strata 2, respectively, in gamma photons / g·s; μ 1 and μ 2 represents the absorption coefficients of strata 1 and strata 2, respectively, in cm. -1 ; when The detection area is divided into three parts: an arc-shaped region A, a cone-shaped region B1, and a sector-shaped region C. The formula for calculating the gamma-ray flux at point O of the detector in each region is as follows: ； ； ； ； In the formula: J A , J B1 and J C These represent the gamma-ray flux at detector point O for the arc-shaped region A, the cone-shaped region B1, and the sector-shaped region C, respectively. δ It is half the arc of the arc-shaped region, in radians. ; r 1 represents the slant height of the cone, in cm. r 1= h ; h Distance between the detector and the geological interface, in cm; r 0 represents the detector's detection radius; ρ 1 and ρ 2 represents the formation density of strata 1 and strata 2, respectively, in g / cm³. 3 ; q 1 and q 2 represents the content of radioactive materials in stratum 1 and stratum 2, respectively, in g / g; α 1 and α 2 represents the average gamma-ray radiation intensity of radioactive materials in strata 1 and strata 2, respectively, in gamma photons / g·s; μ 1 and μ 2 represents the absorption coefficients of strata 1 and strata 2, respectively, in cm. -1 ; Step 3: Based on the actual changes in the azimuth gamma measurement values ​​while drilling, quickly invert and calculate the distance between the drill bit and the layer interface.

2. The data processing method for azimuth gamma during sliding drilling as described in claim 1, characterized in that, The method includes a logging-while-drilling azimuth gamma ray instrument for sliding directional drilling in coal mines. The logging-while-drilling azimuth gamma ray instrument has two gamma detectors, namely detector 1 and detector 2, which are arranged in a front-to-back configuration. The size of the window of the logging-while-drilling azimuth gamma ray instrument is 45°, and the two windows are arranged symmetrically at 180°. The upper gamma face angle Φ is defined as the tool face angle of the logging-while-drilling azimuth gamma ray instrument. An upper gamma face angle of 0° indicates that the tool face angle of the logging-while-drilling azimuth gamma ray instrument is when the center of detector 1 is facing upwards. The measurement range of the upper gamma face angle is 0°~360°.

3. The data processing method for azimuth gamma during sliding drilling as described in claim 1, characterized in that, In step two, the response formula for the fast forward modeling of azimuth gamma during drilling is calculated using a 45° window. This calculation method is also applicable to the response of azimuth gamma at other window angles. Since sliding directional drilling in the coal industry is mainly used for drilling along coal seams, the minimum coal seam thickness is 0.5m, while the maximum detection radius of the gamma detector is 0.4m. Therefore, we only consider the case where the detector detects only two different strata, and do not consider the case where the detection range spans three layers at the same time, i.e., the coal seam thickness is less than 0.4m. When the contribution area is two strata, the detection area is decomposed according to the relationship between the detector's detection range and the strata, and the gamma ray flux of each area is calculated separately. Then, the values ​​of each area are added together to obtain the total gamma ray flux value.

4. The data processing method for azimuth gamma during sliding drilling as described in claim 1, characterized in that, In step three, the method for quickly inverting and calculating the distance between the drill bit and the formation interface is as follows: Based on the differences and rates of change between the upper and lower gamma values ​​measured in real time during drilling, the azimuth gamma detector is analyzed to determine whether the formation boundary has been detected during drilling. When the measured upper and lower gamma values ​​separate, the rates of change of the upper and lower gamma values ​​are calculated. The drilling direction is determined based on the sign of the rate. Then, based on the relative magnitude of the rates, it is determined whether the upper gamma or the lower gamma changes first. Combined with the formation dip and the upper gamma face angle, the distance between the detector and the formation interface is calculated. The drilling trajectory is adjusted according to the distance to guide drilling.

5. The data processing method for azimuth gamma during sliding drilling as described in claim 4, characterized in that, In step three, the specific method for quickly inverting and calculating the distance between the drill bit and the formation interface is as follows: Step S31: When the drill bit is drilling in the target layer and the distance between the azimuth gamma logging tool and the formation interface is much greater than the detection range of the azimuth gamma detector, the upper and lower azimuth natural gamma curves coincide. Step S32: When the drill bit penetrates from the low radioactive strata to the high radioactive surrounding rock, the upper gamma count increases first, followed by the lower gamma count. The upper gamma count is larger than the lower gamma count, and the rate of increase of the upper gamma count is faster than that of the lower gamma count. This indicates that the drill bit is drilling in the upper direction and may need to drill out of the reservoir from the upper direction. At this time, the drill bit direction should be adjusted in time to make it drill in the lower direction. Step S33: When the drill bit drills from the high radioactive stratum of the upper surrounding rock to the low radioactive target layer, the lower gamma decreases first, and the upper gamma decreases later. The upper gamma is larger than the lower gamma, and the rate of decrease of the lower gamma is faster than that of the upper gamma. The azimuth logging tool penetrates from the roof into the coal seam. Step S34: When the drill bit drills from the low radioactivity stratum to the high radioactivity surrounding rock, the lower gamma increases first, and the upper gamma increases later. The lower gamma is larger than the upper gamma, and the rate of increase of the lower gamma is faster than that of the upper gamma. The azimuth logging tool penetrates from the coal seam to the bottom plate. Step S35: When the drill bit drills from the high-radioactivity surrounding rock to the low-radioactivity target layer, the upper gamma decreases first, followed by the lower gamma, and the lower gamma is larger than the upper gamma. The rate at which the upper gamma decreases is faster than the rate at which the lower gamma decreases. The azimuth logging tool travels from the bottom plate into the coal seam.

6. The data processing method for azimuth gamma during sliding drilling as described in claim 5, characterized in that, In step three, when the azimuth gamma logging tool drills through different radioactive formations, the distance between the drill bit and the formation interface is calculated from the distance between the azimuth gamma detector and the formation interface. The specific method for calculating the distance between the drill bit and the formation interface is as follows: Step a: When the formation dips and the azimuth logging tool penetrates from the low-radioactivity target coal seam into the high-radioactivity surrounding mudstone layer, and when the reading of detector 1 is upper gamma, Φ is different. When detector 1 can detect the interface, and when detector 1 detects the upper interface, detector 2 cannot detect the upper interface, a separation occurs between the upper and lower gamma. D is the detection radius of the detector, and the distance between detector 1 and the formation. H 1. As shown in the following formula: Step b: When the formation dips and the azimuth logging tool penetrates from the low-radioactivity target coal seam into the high-radioactivity surrounding mudstone layer, and when the reading of detector 2 is upper gamma, Φ is different, and the lower detector can detect the interface, the distance between detector 2 and the formation is... H 2, as shown in the following formula: Step c: When the up-dip, azimuth-based logging tool penetrates from the low-radioactivity target coal seam into the high-radioactivity surrounding mudstone layer, and when the reading of detector 1 is the upper gamma, Φ is different. When detector 1 can detect the interface, detector 2 cannot detect the upper interface, and a separation occurs between the upper and lower gamma. D is the detection radius of the detector, and the distance between detector 1 and the formation. H 1. As shown in the following formula: Step d: When the updip, azimuth-based logging tool penetrates from the low-radioactivity target coal seam into the high-radioactivity surrounding mudstone layer, and when the detector 2 reading is high gamma, and Φ is different, and detector 2 can detect the interface, the distance between detector 2 and the formation is... H 2, as shown in the following formula: Step e: When the formation dips and the azimuth logging tool penetrates from the upper surrounding mudstone layer into the coal seam, and when the detector 2 reading is at the lower gamma, the distance between the detector 2 and the formation is determined when the upper gamma face angle is different. H 2, as shown in the following formula: Step f: When the formation dips and the logging-while-drilling azimuth gamma ray tool penetrates from the upper surrounding mudstone layer into the coal seam, and when the reading of detector 1 is lower gamma and the upper gamma face angle is different, the distance between detector 1 and the formation is... H 1. As shown in the following formula: Step g: When the formation dips upwards, and the azimuth logging tool penetrates from the upper surrounding mudstone layer into the coal seam, and when the detector 2 reading is lower gamma, the distance between detector 2 and the formation is... H 2. As shown in the following formula: Step h, when the formation dips upwards, and the azimuth logging tool penetrates from the upper surrounding mudstone layer into the coal seam, and when the reading of detector 1 is lower gamma, the distance between detector 1 and the formation is... H 1. As shown in the following formula: In the formulas for steps a to h: Φ The upper gamma angle, in degrees; β The dip angle of the strata, in degrees; D The detection radius of the azimuth logging-while-drilling tool is in cm. Step i, Distance between drill bit and formation interface: When the azimuth logging-while-drilling tool penetrates from the coal seam towards the roof, the distance between the drill bit and the formation interface along the drilling direction is calculated based on the vertical distance of the detector from the formation. L and the distance of the drill bit's vertical interface H bit As shown in the following formula: In the formula: H This refers to the vertical distance between the detector and the stratum analyzed earlier. H = H 1 or H = H 2; α is the angle between the azimuth logging tool and the formation, in degrees. L tb Let be the distance from the detector to the drill bit. The distance from detector 1 to the drill bit is . L tb1 The distance from detector 2 to the drill bit is Ltb2 , L tb = L tb1 or L tb = L tb2 , Unit: cm.

7. A method for applying azimuth gamma during sliding drilling, characterized in that, The method employs the data processing method for azimuth gamma during sliding drilling as described in any one of claims 1 to 6, and adjusts the drilling trajectory in real time by integrating the forward and inverse models of the azimuth gamma during drilling.

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