Method for improving drilling rate of gas reservoirs of tight sandstone with strong heterogeneity by three-dimensional modeling

Abstract

The application discloses a method for improving drilling rate of strong heterogeneity tight sandstone gas reservoir by three-dimensional modeling, and relates to the technical field of oil and gas field exploration and development, and comprises the following steps: S1, establishing a high-precision velocity model; S2, establishing a forward model of a horizontal well area; S3, combining with the actual drilling of adjacent wells to analyze and summarize the geological significance represented by the seismic response characteristics of each part of the horizontal section; S4, establishing a high-precision three-dimensional geological structure model jointly constrained by well and seismic data; and S5, establishing a lithology model, and using the lithology model to guide the design of the target depth and the horizontal section trajectory control method with the highest reservoir drilling rate. The method comprehensively utilizes technical means in aspects of the earthquake, geology, well logging, modeling and guiding, realizes the whole process control from the horizontal well trajectory design to the target depth prediction and the real-time tracking adjustment of the horizontal section, and thus the effect of improving the reservoir drilling rate is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas field exploration and development, more particularly to a method for improving the drilling rate of reservoirs of strong heterogeneity tight sandstone gas reservoirs based on three-dimensional modeling. BACKGROUND

[0002] Surig gas field is one of the typical representatives of tight sandstone gas reservoirs in China, and the He 8 and Shanxi sections of the reservoirs have the characteristics of low porosity, low permeability and strong heterogeneity. With the deepening of exploration and development, the gas field currently presents a clear situation of poor quality of resources, and in order to achieve profitable development, the development mode is gradually changed from the original straight cluster well to the horizontal well, and the yield of the horizontal well depends on the reservoir drilling rate, so how to improve the reservoir drilling rate of the horizontal well is of great significance to the stable production of the gas field.

[0003] At present, the industry has more research on improving the reservoir drilling rate of horizontal wells in shale oil and shale gas, and usually the target thickness of such oil and gas reservoirs is large when deploying horizontal well targets, the sedimentation is stable, the formation between wells changes little, and it is easy to predict, and the requirements for the target depth of the horizontal well and the adjustment accuracy while drilling are low. At the same time, the current prediction of the structure of the target layer of the horizontal well for strong heterogeneity oil and gas reservoirs is based on the overall seismic structure interpretation of the block, and the velocity field is not corrected according to the real drilling of the local small well area, so it is impossible to obtain more accurate microstructure characteristics of the horizontal section. In terms of reservoir prediction, the existing research mainly stays on the plane prediction, and the longitudinal development depth and change characteristics of the entire horizontal section are not predicted, which leads to the fact that the designed horizontal well trajectory is more likely to drill out the reservoir during the real drilling process, and the out-of-layer cannot be timely and effectively adjusted.

[0004] Therefore, the existing method and technology are not suitable for guiding the horizontal well drilling of the fluvial facies strong heterogeneity tight sandstone gas reservoirs in Surig gas field. In order to solve the problem that the reservoir drilling rate of the horizontal well is difficult to improve due to the poor physical property, thin thickness, development of interlayer and rapid longitudinal and lateral changes of the tight sandstone reservoirs in Surig gas field, it is necessary to start from the horizontal well trajectory design before drilling and the dynamic optimization of the trajectory while drilling, to more accurately identify and predict the microstructure of the horizontal well trajectory position, the sand body and the reservoir in the longitudinal and lateral directions, to establish a three-dimensional geological model on the basis of the achievement, to realize the optimal horizontal well trajectory design and real-time tracking adjustment during the drilling process, and to improve the reservoir drilling rate of the horizontal well. Therefore, a method for improving the reservoir drilling rate of strong heterogeneity tight sandstone gas reservoirs based on three-dimensional modeling is urgently needed to improve the reservoir drilling rate of the horizontal well. SUMMARY

[0005] In order to overcome the defects existing in the prior art, the application discloses a three-dimensional modeling method for improving drilling rate of a strong heterogeneity tight sandstone gas reservoir, and aims to solve the problem of inaccurate identification of a small well area microstructure, sand body and reservoir distribution law of a horizontal well trajectory position in the prior art, and proposes a horizontal well trajectory optimization design and dynamic adjustment method. The method comprehensively utilizes technical means such as seismic, geology, logging, modeling and guiding, realizes full-process control from horizontal well body trajectory design to target depth prediction and real-time tracking adjustment of the horizontal section, and thus the effect of improving the reservoir drilling rate is achieved.

[0006] In order to achieve the above object, the technical scheme adopted by the application is as follows:

[0007] The application discloses a three-dimensional modeling method for improving drilling rate of a strong heterogeneity tight sandstone gas reservoir, and aims to solve the problem of inaccurate identification of a small well area microstructure, sand body and reservoir distribution law of a horizontal well trajectory position in the prior art, and proposes a horizontal well trajectory optimization design and dynamic adjustment method. The method comprehensively utilizes technical means such as seismic, geology, logging, modeling and guiding, realizes full-process control from horizontal well body trajectory design to target depth prediction and real-time tracking adjustment of the horizontal section, and thus the effect of improving the reservoir drilling rate is achieved.

[0008] I. Microstructure prediction

[0009] S1, fine calibration of composite records of adjacent wells in a small well area where the horizontal well is located is performed, a high-precision velocity model is established, and the microstructure of the small well area is predicted by using the velocity model.

[0010] In the above step, by performing fine calibration of composite records of adjacent wells in a small well area where the horizontal well is located, a high-precision velocity model is established, and more accurate prediction of the microstructure of the small well area is completed.

[0011] Preferably, the S1 step comprises the following steps: fine calibration of composite records of straight cluster wells in the same well area, fitting of multi-well time-depth curves, establishment of a high-precision velocity model, and prediction of the microstructure of the well area where the deployed well is located in combination with the velocity model and geologic stratification of the actual drilled well position.

[0012] II. Prediction of high-quality sand body distribution

[0013] S2, a forward model of the horizontal well area is established, the seismic response mode of the favorable sand body is determined, and the spatial distribution characteristics of the sand body and the reservoir of the target layer section of the horizontal well are quantitatively predicted in combination with the post-stack gamma inversion result.

[0014] In the above step, by establishing a forward model of the horizontal well area, the seismic response mode of the favorable sand body is determined, and the spatial distribution characteristics of the sand body and the reservoir of the target layer section of the horizontal well are quantitatively predicted in combination with the post-stack gamma inversion result.

[0015] Preferably, the S2 step comprises the following steps: a forward model of the sand body combination characteristics of the drilled well in the well area is established, the seismic response mode of the favorable sand body is determined, the minimum amplitude attribute with high sensitivity to sandstone development is selected according to the analysis result of the seismic response mode of the high-quality sand body, the sand body planar distribution is predicted, and the spatial distribution of the high-quality sand body is quantitatively predicted by using the post-stack seismic facies-controlled gamma inversion result.

[0016] III. Analysis of reservoir response characteristics

[0017] S3. Analyzing the geological significance of the seismic response characteristics of each part of the horizontal section in combination with the actual drilling of adjacent wells;

[0018] Preferably, the S3 step includes: comparing and analyzing the matching degree of the reservoir response characteristics of the geophysical prospecting data in combination with the actual drilling of adjacent wells, and summarizing the geological significance represented by the response characteristics of each part of the horizontal section, including lithology change, reservoir change, and structural change.

[0019] IV. Establishing a three-dimensional geological model

[0020] S4. Establishing a high-precision three-dimensional geological structure model jointly constrained by well and seismic data by comprehensively utilizing the prediction results, analysis results, and geophysical prospecting data, actual drilling data of drilled wells, and geological stratification data in the work area.

[0021] In the above steps, on the basis of the above understanding results, a high-precision three-dimensional geological structure model jointly constrained by well and seismic data is established by comprehensively utilizing the geophysical prospecting data in the work area, actual drilling data of drilled wells, and geological stratification data.

[0022] V. Target depth and horizontal section trajectory control

[0023] S5. Under the constraint of the three-dimensional geological structure model, a lithology model is established by utilizing logging data and seismic depth domain gamma data volume, respectively, and the lithology model is corrected to obtain a more accurate lithology model, and the corrected lithology model is used to guide the design of a target depth and horizontal section trajectory control method with the highest reservoir drilling rate.

[0024] In the above steps, under the constraint of the above structure model, a lithology model is established by utilizing logging data and seismic depth domain gamma data volume, respectively, a more accurate lithology model is obtained after correction through comparison and analysis, and the model is used to guide the design of a target depth and horizontal section trajectory with the highest reservoir drilling rate, while taking into account the smoothness of the well trajectory to reduce the difficulty of engineering implementation.

[0025] Preferably, the S5 step includes: under the constraint of the three-dimensional geological structure model, a lithology model 1 is established by utilizing the gamma curve in the logging data of drilled adjacent wells; a lithology model 2 is established by utilizing the depth domain gamma data volume provided by the seismic data, a more accurate lithology model 3 is obtained after correction through comparison and analysis of the lithology models 1 and 2, and finally, the target depth and horizontal section trajectory with the highest sand body and reservoir drilling rate are designed by utilizing the corrected heart elevation and the lithology model 3.

[0026] Preferably, the target depth and horizontal section trajectory control method comprises: during the horizontal well implementation process, the target depth control is a dynamic process, the real-time loading of the while-drilling gamma curve of the horizontal well in the three-dimensional geological model is compared with the marker layers of each level of the reference well, the target vertical depth h is dynamically corrected and the design trajectory is corrected, and the target depth error is maximally reduced.

[0027] Preferably, the target vertical depth h is:

[0028] h = h0 - (KB0 - KB1) - (h1 - h2);

[0029] Wherein, h is a value dynamically calculated in real time according to the comparison of the marker layers of each level, h0 is the design target vertical depth, KB0 is the predicted heart elevation, KB1 is the re-measured heart elevation, h1 is the elevation of the drilled marker layer, and h2 is the elevation of the marker layer of the reference well, and the units of the above parameters are m.

[0030] Preferably, the target depth and horizontal section trajectory control method comprises: when the horizontal well is drilled to the top of the reservoir, different trajectory control methods are adopted according to the reservoir development conditions, comprising:

[0031] If the gas logging shows normal, the designed trajectory after the target depth correction is followed to increase the inclination to target;

[0032] If the gas logging shows low or discontinuous, the inclination is increased to target after the depth of the gas logging rising is further explored;

[0033] If the gas logging shows no obvious change, the inclination is increased to drill back to the predicted middle position of the reservoir after the position 1-2 m above the predicted bottom boundary of the sand body is reached.

[0034] Preferably, the target depth and horizontal section trajectory control method comprises: after the horizontal well increases the inclination to target, the stratum is drilled according to the predicted stratum dip angle first, the accuracy of the predicted structural dip angle is evaluated by analyzing the relative position of the bottom of the well in the sand body and the reservoir, the real stratum dip angle is calculated in real time to adjust the structural model, and the basis for the inclination adjustment in the next drilling process is provided.

[0035] Preferably, the target depth and horizontal section trajectory control method comprises: when the horizontal well encounters mudstone or the reservoir is not developed and inconsistent with the model for more than 50 m of the well section, the latest structural and geological understanding is obtained through the while-drilling tracking analysis, the structural and lithological model is updated in real time, the trajectory of the subsequent well section is optimized, the basis for the timely adjustment of the horizontal well is provided, and finally the sand body and the reservoir are timely adjusted and recovered, the structural dip angle and the geological understanding are continuously verified and updated, the subsequent horizontal section implementation is guided, and the reservoir drilling rate of the horizontal well is maximally improved.

[0036] The beneficial effects of the present application are:

[0037] The present application improves the accuracy of the micro-structure and target sand body and longitudinal and lateral distribution prediction of the small well area where the horizontal well is located, obtains more accurate stratigraphic dip and reservoir spatial distribution characteristics of the horizontal section position target layer, reduces the average error of the horizontal well prediction into the target vertical depth from 5m to 3m, solves the problem that the strong heterogeneous dense sand gas reservoir is thin, changes fast, especially the longitudinal reservoir development position and the micro-structure of the horizontal section is difficult to accurately predict, realizes the good effect of well trajectory optimization design and real-time adjustment, and significantly improves the reservoir drilling rate of the horizontal well.

[0038] After the application is applied to the trajectory design and geosteering work of 8 horizontal wells in the same well area and the same layer of the Sulige gas field, the average reservoir drilling rate of 79.4% is realized, which is a super-expected result, and the average reservoir drilling rate of the horizontal well without using the application technology is 70.47%, which is significantly improved. At the same time, most of the horizontal well trajectories drilled under the guidance of the technology are smooth and located in the lower part of the reservoir, which is beneficial to the completion operation and the later fracturing reconstruction. BRIEF DESCRIPTION OF DRAWINGS

[0039] Fig. 1 The method for improving the reservoir drilling rate of the horizontal well is a specific implementation flowchart of the present application.

[0040] Fig. 2 The horizontal well forward model prediction high-quality sand body (i.e. reservoir) is the present application.

[0041] Fig. 3 The horizontal well drilling trajectory and sandstone and mudstone prediction model in the specific embodiment of the present application. DETAILED DESCRIPTION

[0042] The concept, specific structure and generated technical effects of the present application will be described clearly and completely in the following combined with the embodiments and the drawings, so as to fully understand the purpose, features and effects of the present application.

[0043] The present embodiment is aimed at a horizontal well in the Sulige gas field, and the horizontal well target depth prediction, trajectory optimization design and dynamic adjustment are carried out.

[0044] Firstly, by collecting the well logging data of the adjacent wells in the well area and carrying out fine calibration of the synthetic record, a high-precision velocity model is established, and the microstructure of the well area is predicted in combination with the velocity model and the geological stratification of the actual drilling well position, obtaining the preliminary prediction result that the structure of the front section of the horizontal section is basically horizontal and the tail section is inclined downward. Then, the longitudinal and lateral distribution characteristics of the high-quality sand body (i.e. reservoir) in the horizontal well area are successfully depicted in combination with the attribute and inversion prediction results. Based on the above understanding and results, a high-precision three-dimensional geological structure model and lithology model are established under the joint constraint of well and seismic data, and the horizontal well trajectory with the highest reservoir drilling rate and smooth wellbore trajectory is designed with the help of the model. During the process of steering while drilling, the re-measured supplementary altitude and the correction of each level of marker layer are used to continuously correct the target vertical depth and the designed trajectory, so as to finally ensure that the well successfully lands in the target layer of He 8-3 and the error of the target vertical depth is small. During the process of horizontal drilling along the layer after landing, two sections of high gamma mudstone are found in the front section of the horizontal section, and the lithology model is corrected through real-time loading of the while-drilling curve and analysis of the adjacent well drilling and seismic waveform changes. It is considered that the two mudstones are caused by the thinning of the sand body, rather than the structural upwarping. Therefore, the strategy of horizontal drilling is adopted after the sand body is increased and retrieved, the reservoir is stable in the middle and rear sections of the horizontal section, and the tail section reservoir is poor, which is consistent with the previous prediction result.

[0045] Specifically, as shown in Figs. 1-3 A method for improving reservoir drilling rate of strong heterogeneous tight sandstone gas reservoir based on three-dimensional modeling, comprising the following steps:

[0046] Step 1: Through fine calibration of the synthetic record of the same well area straight cluster well, fitting the multi-well time-depth curve, establishing a high-precision velocity model, and combining the velocity model and the geological stratification of the actual drilling well position, the microstructure of the well area is predicted to realize the accurate control of the horizontal section trajectory.

[0047] Step 2: By establishing a forward model of the sand body combination characteristics of the drilled wells in the well area, the seismic response mode of the favorable sand body is determined, and according to the analysis result of the seismic response mode of the high-quality sand body, the minimum amplitude attribute with high sensitivity to sandstone development is selected by qualitative prediction through post-stack seismic attribute, and the planar distribution of the sand body is predicted, and then the spatial distribution of the high-quality sand body is quantitatively predicted by using the post-stack seismic facies-controlled gamma inversion result. The longitudinal and lateral distribution characteristics of the high-quality sand body (i.e. reservoir) in the horizontal well area are successfully depicted in combination with the attribute and inversion prediction results.

[0048] Step 3: The matching degree of the reservoir response characteristics of the geophysical prospecting data is compared and analyzed in combination with the actual drilling situation of the adjacent wells, and the geological significance represented by the response characteristics of each part of the horizontal section is summarized, including lithology change, reservoir change, structural change, etc., to guide the pre-drilling scheme design of the horizontal well trajectory.

[0049] Step 4: Based on the data of drilled wells and logging, geological well-to-well correlation and stratification data, and the understanding and results obtained in steps 1-3, a high-precision 3D geological structure model is established under the joint constraint of well and seismic data.

[0050] Step 5: Under the constraint of the model constructed in step 4, a lithology model 1 is established using the gamma curve in the logging data of drilled adjacent wells; at the same time, a lithology model 2 is established using the depth domain gamma data volume provided by the seismic. Through comparative analysis of the lithology models 1 and 2, a more accurate lithology model 3 is obtained after correction. Finally, the target depth and horizontal section trajectory with the highest drilling rate of sand bodies and reservoirs are designed using the corrected lithology model 3 and the corrected elevation of the re-measured heart, so as to maximize the smoothness of the well trajectory and reduce the difficulty of engineering implementation.

[0051] The classification standard of lithology in the lithology model is based on the experience values obtained from a large number of drilled wells in the Sulige Gas Field. The gamma value ranges of reservoir, sandstone and mudstone are less than 75 API, less than 110 API and greater than or equal to 110 API, respectively.

[0052] The lithology model 3 is obtained based on the comparison and correction of the previous two models. The part that the two models agree with each other is retained as the lithology model with high reliability, and the part that the two models do not agree with each other is corrected by geologists based on the analysis of the geological characteristics of the well area, the drilled adjacent wells and the well spacing.

[0053] Step 6: During the implementation of the horizontal well, the target depth control is a dynamic process. First, appropriate adjacent wells are selected as reference wells according to the well spacing and geological understanding, including adjacent wells with far well spacing but the target interval located in the same channel. Then, through well-to-well correlation analysis of the reference wells, multiple stable lithologies with typical regional sedimentary characteristics or commonly existing in most reference wells are selected as multiple marker beds. Finally, by loading the real-time gamma curve of the horizontal well and comparing it with the marker beds of the adjacent wells, the real and accurate structure height and formation thickness variation of the target interval and the adjacent wells are mastered, so as to realize the real-time dynamic correction of the target vertical depth h of point A (usually the middle position of the reservoir is selected as the target), and maximize the reduction of the target depth error.

[0054] The example horizontal well is located in the Sulige Gas Field, and the main target intervals are He 8 and Shan 1 intervals. Therefore, the lithology of the upper interval is mainly selected as the marker bed, including the sandstone at the bottom of Shiqianfeng, the peak-shaped mudstone at the top of He 7 interval, the flooding mudstone at the top of the lower He 8 interval, the "camel neck" sandstone of the lower He 8 interval, the deep black high-gamma mudstone at the top of Shan 1 interval, and the coal bed or carbonaceous mudstone at the top of Shan 2 interval.

[0055] The calculation formula of the target vertical depth h is: h = h0-(KB0-KB1)-(h1-h2)

[0056] Wherein h is a value calculated in real time according to the contrast of each level of marker layer, h0 is the designed target depth, KB0 is the predicted elevation of the heart, KB1 is the re-measured elevation of the heart, h1 is the elevation of the real drilling marker layer, h2 is the elevation of the reference well marker layer, and the units of the above parameters are m.

[0057] Step 7: When drilling to the top of the reservoir, different trajectory control schemes are determined according to the development of the reservoir, such as: if the gas logging shows normal, then the designed target depth h and the updated design trajectory are used to increase the inclination to target; if the gas logging shows low or discontinuous, then the inclination is increased to target at the depth where the gas logging rises; if the gas logging shows no obvious change, then the inclination is increased to the position 1-2 m above the predicted bottom boundary of the sand body, and then the drilling is back to the predicted middle position of the reservoir for drilling along the layer.

[0058] Step 8: After the inclination to target, the inclination is kept basically consistent with the predicted dip angle for drilling along the layer, and the relative position of the bottom hole in the sand body and the reservoir is analyzed by comprehensively analyzing the elevation, grain size, gamma curve and gas logging change characteristics of the real drilling well and the adjacent well, so as to evaluate the accuracy of the structure predicted by well-seismic combination and to calculate the real dip angle in real time to adjust the structure model, thereby providing a basis for the inclination adjustment in the next drilling process.

[0059] When the horizontal well drills the characteristic points (marker minerals, characteristic gamma values, etc.) in the sand body for more than twice or the top and bottom are touched, the dip angle α of the stratum can be calculated by the formula α = arctan (H / L). In the formula, α is the dip angle of the stratum, the unit is °; H is the vertical elevation difference of the same interface for two times, the unit is m; and L is the plane displacement between the same interface or the characteristic points, the unit is m.

[0060] Step 9: When the horizontal well drills mudstone or the reservoir is not developed for more than 50 m of well section, etc., which does not match the model, the real-time loading of the while-drilling gamma and gas logging curves is used, combined with the latest structure and geological knowledge obtained by the while-drilling tracking analysis, to dynamically update the structure and lithology model, thereby providing a basis for the timely adjustment and trajectory optimization of the subsequent well section of the horizontal well. After adjusting and returning to the sand body and the reservoir, steps 8 and 9 are repeatedly performed to finally achieve the purpose of improving the reservoir drilling rate of the horizontal well.

[0061] In the detailed description of the method in this embodiment, some specific and original details are described in detail, and the parts not described in detail, such as the high-precision velocity model, the forward model, the structure model, the lithology model, etc. in steps 1-4, are all common technical means and methods in the industry, and can be completely understood by those skilled in the art, so they are not described in detail.

[0062] The above describes the embodiments of the present application in detail, but the present application is not limited to the above-mentioned embodiments, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the present application.

Claims

1. A method for improving the drilling rate of highly heterogeneous tight sandstone gas reservoirs using three-dimensional modeling, characterized in that, Includes the following steps: S1. Perform synthetic record fine calibration on adjacent wells in the small well area where the horizontal well is located, establish a high-precision velocity model, and use the velocity model to predict the micro-structure of the small well area. S2. Establish a forward model of the horizontal well area, clarify the seismic response mode of the favorable sand body, and then combine the post-stack gamma inversion results to quantitatively predict the spatial distribution characteristics of the sand body and reservoir in the target section of the horizontal well. S3. Combine the actual drilling data of adjacent wells to analyze and summarize the geological significance represented by the seismic response characteristics of each part of the horizontal section; S4. By comprehensively utilizing the prediction results, analysis results, geophysical data of the work area, actual drilling data of drilled wells, and geological stratification data, a high-precision three-dimensional geological structure model constrained by well and seismic data is established. S5. Under the constraints of the three-dimensional geological structure model, a lithological model is established using well logging data and seismic depth domain gamma data volume, and the lithological model is corrected to obtain a more accurate lithological model. Then, the corrected lithological model is used to guide the design of the target depth and horizontal segment trajectory control method with the highest reservoir drilling encounter rate. The target depth and horizontal trajectory control method includes: during the horizontal well implementation, the target depth control is a dynamic process. By loading the horizontal well's gamma ray curve while drilling into the three-dimensional geological model in real time, and comparing it with the marker layers of the reference well, the target depth h and the designed trajectory are dynamically corrected. The vertical depth h of the target entry is: h=h0-(KB0-KB1)-(h1-h2); Where h is the value obtained by real-time dynamic calculation based on the comparison of each level of marker layer, h0 is the designed vertical depth of the target, KB0 is the expected core filling elevation, KB1 is the remeasured core filling elevation, h1 is the actual drilled marker layer elevation, and h2 is the reference well marker layer elevation. All the above parameters are in meters.

2. The drilling success rate method as described in claim 1, characterized in that, The S1 step includes: finely calibrating the composite record of vertical cluster wells in the same well area, fitting the time-depth curves of multiple wells, establishing a high-precision velocity model, and combining the velocity model with the geological stratification of the actual drilled well location to predict the micro-structure of the small well area where the deployed well is located.

3. The drilling success rate method as described in claim 1, characterized in that, The S2 step includes: establishing a forward model of the combined characteristics of drilled sand bodies in the well area, identifying the seismic response mode of favorable sand bodies, selecting the minimum amplitude attribute with high sensitivity to sandstone development based on the analysis results of the seismic response mode of high-quality sand bodies, predicting the planar distribution of sand bodies, and then using the post-stack seismic phased gamma inversion results to quantitatively predict the spatial distribution of high-quality sand bodies.

4. The drilling success rate method as described in claim 1, characterized in that, The S3 step includes: comparing and analyzing the matching degree of reservoir response characteristics in geophysical data with the actual drilling conditions of adjacent wells, and summarizing the geological significance represented by the response characteristics of each part of the horizontal section, including lithological changes, reservoir changes, and structural changes.

5. The drilling success rate method as described in claim 1, characterized in that, The S5 step includes: under the constraints of the three-dimensional geological structure model, establishing lithology model 1 using gamma curves from the logging data of adjacent drilled wells; simultaneously establishing lithology model 2 using depth domain gamma data volume provided by seismic data; by comparing and analyzing lithology models 1 and 2, obtaining a more accurate lithology model 3 after correction; and finally, using the core elevation after actual drilling and re-measurement and lithology model 3, designing the target depth and horizontal trajectory with the highest drilling encounter rate for sand bodies and reservoirs.

6. The drilling success rate method as described in claim 1, characterized in that, The target depth and horizontal segment trajectory control methods include: when a horizontal well is drilled to the top of the reservoir, different trajectory control methods are adopted according to the reservoir development, including: If the air measurement shows normal, proceed with the increased angled entry into the target according to the designed trajectory after pre-target calibration. If the gas reading is low or discontinuous, continue to descend to the depth where the gas reading rises and then enter the target at an angle. If the gas logging results remain unclear, then after drilling down to a position 1-2m above the predicted bottom boundary of the sand body, drill back to the predicted middle position of the reservoir and continue drilling along the formation.

7. The drilling success rate method as described in claim 1, characterized in that, The target depth and horizontal segment trajectory control method includes: after the horizontal well is increased in inclination and enters the target, drilling is first carried out in line with the formation dip angle according to the predicted formation dip angle. The accuracy of the predicted structural dip angle is evaluated by analyzing the relative position of the bottom of the well in the sand body and the reservoir. The actual formation dip angle is calculated in real time to adjust the structural model.

8. The drilling success rate method as described in claim 1, characterized in that, The target depth and horizontal segment trajectory control method includes: when a horizontal well encounters mudstone or a continuous well section with reservoir underdevelopment exceeding 50m that does not conform to the model, the latest structural and geological understanding obtained through drilling tracking analysis is used to update the structural and lithological model in real time; after timely adjustment and recovery of sand bodies and reservoirs, the structural dip angle and geological understanding are continuously verified and updated to guide the implementation of subsequent horizontal segments.

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