A method for quickly optimizing and adjusting a horizontal well trajectory

Abstract

This invention relates to a method for rapid optimization and adjustment of horizontal well trajectory, comprising the following steps: 1) acquiring logging data from the pilot well of the horizontal well, loading the logging data onto the seismic interpretation area to obtain and save the time-depth relationship; the time-depth relationship is the correspondence between depth data in the logging data and time data in the seismic data; 2) after backfilling the pilot well, sidetracking, acquiring logging data from the horizontal well sidetracking and the horizontal section, the logging data including at least lithological data, total hydrocarbon data from gas logging, etc., loading the logging data onto the seismic interpretation area, obtaining a well trajectory curve on the seismic interpretation area, the well trajectory curve including the corresponding lithological changes; 3) loading the time-depth relationship of this well onto the well trajectory curve, assigning seismic time information to the horizontal section; displaying the well trajectory curve on a seismic profile in the time domain; 4) optimizing and adjusting the horizontal well trajectory based on the current drilling encounter reflected by the logging curve and the corresponding seismic response.

Description

Technical Field

[0001] This invention relates to a method for rapid optimization and adjustment of horizontal well trajectories, belonging to the field of oil and gas field development technology. Background Technology

[0002] Horizontal well drilling is one of the current methods to improve oil and gas production capacity and has been widely used in oilfield development. However, with the increasing difficulty of developing formations, thin reservoirs, and lateral heterogeneity, the required reservoir encounter rate has increased. How to utilize existing data to guide rapid adjustments to the drilling trajectory during the drilling process to improve drilling efficiency and reservoir gas detection rate has become a major issue in the industry.

[0003] Currently, drilling technology is advanced and drilling speeds are fast. However, if mudstone is encountered during drilling, the next drilling trajectory and direction need to be quickly determined based on comprehensive data such as seismic and geological data. In the industry, horizontal well trajectory optimization is mainly completed based on depth-domain seismic interpretation results, such as the paper "High-Precision Depth-Domain Stochastic Simulation Inversion Method Applicable to Horizontal Well Trajectory Design" by Qin Xuefei and Li Wenyu et al., which is based on sparse pulse inversion and then establishes a well-controlled velocity field. This method requires a high degree of well control and has relatively low efficiency. The paper "Application of Well-Support Combined Velocity Modeling in Horizontal Well Trajectory Design" by Zhang Bingming and Han Lei et al. mentions that the process requires multiple steps, from well logging processing to seismic velocity refinement, with a calculation time of 1-2 working days per well, resulting in a long cycle. If the degree of well control is low and the lateral velocity is inaccurate, it can easily create the illusion of structural changes, affecting the trajectory design during horizontal drilling. Meanwhile, some literature in this industry mentions methods for horizontal well trajectory optimization that combine well logging and seismic analysis, but the specific implementation steps and effects of quickly applying well logging data to seismic-related results are not fully demonstrated. Summary of the Invention

[0004] The purpose of this invention is to provide a method for rapid optimization and adjustment of horizontal well trajectories, in order to solve the problem that horizontal well trajectory optimization is mainly completed based on the results of depth domain seismic interpretation.

[0005] To achieve the above objectives, the present invention includes: The present invention provides a method for rapid optimization and adjustment of horizontal well trajectory, comprising the following steps: 1) Obtain logging data from horizontal well pilot wells, load the logging data into the seismic interpretation work area to obtain the time-depth relationship and save it; the time-depth relationship is the correspondence between depth data in the logging data and time data in the seismic data; 2) After backfilling the pilot well, sidetrack the horizontal well and obtain logging data of the horizontal section. The logging data includes at least lithological data. Load the logging data into the seismic interpretation area and obtain the well trajectory curve on the seismic interpretation area. The well trajectory curve includes the corresponding lithological changes. 3) Load the time-depth relationship of this well onto the well trajectory curve and assign seismic time information to the horizontal segment; display the well trajectory curve on the seismic profile in the time domain; 4) Optimize and adjust the horizontal well trajectory based on the current drilling conditions reflected in the logging curves and the corresponding seismic response.

[0006] This invention provides a method for rapid optimization and adjustment of horizontal well trajectories. It accurately and quickly loads information from lithological logging, gamma ray logging, and total hydrocarbon logging of the horizontal section during actual drilling onto a time-domain seismic profile of the horizontal section. Based on the differences in lateral structure and seismic waveforms in the conventional seismic profile and relevant reservoir prediction results, the method predicts the drilling profile of the horizontal section of the well. This invention avoids errors caused by inaccuracies in the velocity field after the well reaches depth, which affect the prediction of structure and lateral trajectory. It enables rapid horizontal well trajectory prediction in the time domain, optimizes trajectory adjustment, and improves the drilling rate of reservoir gas logging indications.

[0007] Furthermore, in step 2), when loading the logging data into the seismic interpretation area, north-south and east-west displacements, as well as vertical depth, are also loaded to make the lateral and spatial positions of the horizontal well trajectory more accurate. Furthermore, the logging data also includes total hydrocarbon data; in step 3), the total hydrocarbon trajectory curve is also displayed on the seismic profile in the time domain.

[0008] This invention also displays the full hydrocarbon data on the seismic profile in the time domain, making the drilling trajectory judgment more accurate and the reservoir display effect more intuitive.

[0009] Furthermore, in step 2), before loading the logging data into the seismic interpretation area, the lithology is discretized, different data values ​​are assigned to different lithologies, and different colors are assigned to different lithologies. The discretized lithology curves with different colors are then displayed on the seismic profile.

[0010] Furthermore, the seismic profile also includes an interpretation result profile.

[0011] Furthermore, in steps 1) and 2), the commercial seismic interpretation software Landmark or Jason is used when loading the well logging data and well logging data into the seismic interpretation work area.

[0012] Furthermore, the depth data includes depth sounding and vertical depth.

[0013] Furthermore, the time data is a two-way time. Attached Figure Description

[0014] Figure 1 A feature map representing temporal depth relationships; Figure 2 It is a trajectory diagram for predicting changes in seismic wave groups. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings. Example

[0016] This invention provides a method for rapid optimization and adjustment of horizontal well trajectories. This method loads the horizontal well's lithological logging data into the seismic interpretation area during drilling, eliminating the need for time-depth conversion to generate seismic data volumes. It allows for a more intuitive assessment of lithology, gas-bearing capacity, faults, and structural trends through changes in seismic waveforms, structures, or relevant seismic interpretation results (seismic attributes, pre-stack inversion of gas-bearing capacity, etc.), quickly providing suggestions for the next well trajectory. Simultaneously, it allows for multi-directional, three-dimensional spatial observation of sand body development near the horizontal section, providing a basis for subsequent reservoir stimulation. Specifically, it includes the following steps: 1) Collect and organize relevant information about horizontal wells, merge the actual drilling lithology logging data of the sidetrack section and the horizontal section, and discretize the data.

[0017] Obtain logging data from horizontal well pilot wells, load the logging data into the seismic interpretation work area to obtain the time-depth relationship and save it; the time-depth relationship is the correspondence between depth data in the logging data and time data in the seismic data.

[0018] After backfilling the pilot well, sidetracking is performed to obtain logging data from the horizontal well sidetracking and horizontal section. The sidetracking and horizontal section logging data are then merged to ensure that the information of the merged target area is relatively complete, enabling comparative analysis with adjacent wells and ensuring lateral consistency, thereby obtaining the necessary relevant information about the horizontal well.

[0019] The relevant information for horizontal wells includes wellhead coordinates (coordinates, elevation), actual drilling lithology statistics table of the pilot well (target point A), the information in the table mainly includes: well depth (depth sounding, vertical depth), lithology logging, total hydrocarbon gas logging, drilling trajectory (north-south, east-west displacement) and logging data package, extract commonly used logging curves such as sonic transit time, density, gamma, neutron, etc., and complete the synthetic record calibration.

[0020] A horizontal well pilot well is an inclined section drilled through the target formation. Its purpose is to understand the changes in lithology, physical properties, and structure of the target formation in order to determine the target point parameters for the horizontal section of the horizontal well. Target point A is the starting point of the horizontal section of the horizontal well, the first point where the target formation is drilled, and the target point calculated according to the predetermined drilling design.

[0021] In this embodiment, the lithological logging data is discretized and digitized into three types: medium-coarse sandstone (type 1), fine sandstone (type 2), and mudstone (type 3). This discretization process is quickly generated in Excel using the VB programming language and saved in the format specified by the corresponding seismic interpretation software, typically in text formats such as .TXT or .dat.

[0022] 2) Load the discretized data into the seismic interpretation work area, and finely calibrate the synthetic records of the pilot wells (calibrate the logging data of target point A if there are no pilot wells), determine the time-depth relationship, and save the corresponding time-depth relationship pairs.

[0023] Well logging data was organized according to the formats specified by various commercial software, and the logging data from the pilot well (target point A) was loaded into the seismic interpretation work area. Fine-grained synthetic record calibration was then performed, and the corresponding time-depth pairs were saved. The purpose of synthetic records is to establish a correspondence between the time-domain seismic records and the depth-domain well logging data. Through well-seismic calibration, a series of "time-depth pairs" can be obtained. These "time-depth pairs" consist of discrete points.

[0024] Discretized lithological data is loaded onto the seismic interpretation area. In this embodiment, Jason seismic interpretation software is used. Loading must strictly adhere to the well logging curve types that the software can recognize to ensure correct identification and accurate well-seismic relationship matching. Through practice, with the format shown in Table 1, the well trajectories can be loaded onto the seismic interpretation area completely and accurately, ensuring the accuracy of the lateral comparative analysis.

[0025] Table 1. Types of Lithology Logging Loading Formats

[0026] 3) Load the saved pilot well time-depth relationship onto the loaded actual drilling lithology curve, and assign seismic time information to the horizontal section of the horizontal well.

[0027] Discretized lithology curves and total hydrocarbon displays are sequentially projected onto the seismic profile and interpretation results profile. The appropriate display scale and colors corresponding to different lithologies are adjusted according to the profile size. Referring to commonly used colors for lithology logging, the colors for lithology logging on the seismic profile are defined as follows: medium-coarse sandstone: yellow; fine sandstone: orange; mudstone: earth-colored; total hydrocarbons for gas logging: red line.

[0028] 4) Project the horizontal section of the horizontal well onto the conventional seismic profile of the horizontal section or onto the corresponding time-domain seismic interpretation results. Combine existing seismic and geological knowledge with known well favorable reflection patterns and other relevant seismic interpretation results. Make full use of the high lateral resolution of seismic data and structural changes to further optimize the horizontal well trajectory, predict the next lithological changes encountered during drilling, avoid corresponding geological risks, improve work efficiency, and ensure effective drilling in sand bodies and reservoirs.

[0029] Taking a horizontal well in the clastic rocks of the Ordos Basin as an example, relevant drilling data for this well were collected, including wellhead coordinate information (coordinates, elevation), a lithological statistics table of the pilot well (target point A), and information in the table mainly including: well depth (sounding depth, vertical depth), lithological logging, total hydrocarbon gas logging, drilling trajectory (north-south, east-west displacement), and logging data packages. Commonly used logging curves such as sonic transit time, density, gamma, and neutron were extracted.

[0030] Several data points were compiled and processed according to the formats specified by various commercial software, and the pilot well logging data was loaded into the seismic interpretation work area. Fine synthetic record calibration was performed, and the corresponding time-depth relationship pairs were saved. The longitudinal sampling interval was 0.125 meters, and its characteristics are as follows: Figure 1 As shown in Table 2, the specific data output time-depth relationship includes depth sounding, vertical depth, and seismic two-way time.

[0031] Table 2. Relationship between time and depth of pilot wells 408.74 408.74 275.71 408.89 408.89 275.81 409.04 409.04 275.90 409.19 409.19 275.99 409.35 409.35 276.09 409.50 409.50 276.18 409.65 409.65 276.27 409.80 409.80 276.36 409.96 409.96 276.45 ... ... ... 2042.46 2042.40 1155.67 2042.62 2042.55 1155.74 2042.77 2042.70 1155.82 2042.92 2042.86 1155.89 2043.07 2043.01 1155.97 2043.23 2043.16 1156.04 2043.38 2043.31 1156.12 2043.53 2043.47 1156.19 2043.68 2043.62 1156.27 ... ... ... 3192.17 3070.07 1641.66 3192.32 3070.19 1641.71 3192.48 3070.31 1641.76 3192.63 3070.43 1641.81 3192.78 3070.55 1641.86 3192.93 3070.67 1641.92 3193.08 3070.79 1641.97 3193.24 3070.92 1642.02 3193.39 3071.04 1642.07

[0032] Based on the lithology logging data of a certain well in Table 3, the lithology logging discretization and digitization is defined as three types: medium and coarse sandstone as 1, fine sandstone as 2, and mudstone as 3. This discretization process is quickly generated in Excel using VB programming language and saved in the format specified by the corresponding seismic interpretation software, usually in text format such as .TXT or .dat.

[0033] Table 3. Statistical table of lithology in sidetracking and horizontal sections of the well. 3241 0.025 Brownish-red mudstone 3 3239.49 -1.05 9.28 63.74 3242 0.022 Brownish-red mudstone 3 3240.45 -0.79 9.16 42.47 3243 0.025 Brownish-red mudstone 3 3241.41 -0.52 9.05 120.26 3244 0.028 Light gray fine sandstone 2 3242.36 -0.25 8.94 110.66 3245 0.025 Light gray fine sandstone 2 3243.32 0.01 8.82 107.58 3246 0.036 Light gray fine sandstone 2 3244.28 0.28 8.71 105.00 3247 0.037 Light gray fine sandstone 2 3245.23 0.55 8.59 105.43 3248 0.030 Brownish-red mudstone 3 3246.18 0.84 8.46 105.85 3249 0.027 Brownish-red mudstone 3 3247.13 1.13 8.34 111.94 3250 0.029 Brownish-red mudstone 3 3248.08 1.42 8.21 105.96 3566 0.188 gray mudstone 3 3461.65 196.81 -82.37 114.89 3567 0.102 gray mudstone 3 3461.93 197.68 -82.76 109.81 3568 0.101 gray mudstone 3 3462.22 198.55 -83.16 102.71 3729 5.820 grayish-white medium sandstone 1 3474.60 344.73 -147.47 49.20 3843 7.133 Light gray fine sandstone 2 3475.61 447.52 -196.71 79.74 3844 7.499 Light gray fine sandstone 2 3475.60 448.41 -197.17 109.10 3845 1.627 gray fine sandstone 2 3475.59 449.30 -197.63 137.32 3846 0.835 gray fine sandstone 2 3475.58 450.19 -198.09 110.67 3847 0.276 gray fine sandstone 2 3475.58 451.08 -198.55 121.71 3848 0.241 gray fine sandstone 2 3475.57 451.97 -199.01 133.24 3857 0.240 gray fine sandstone 2 3475.44 459.97 -203.13 107.75 3858 0.185 gray fine sandstone 2 3475.42 460.86 -203.58 102.66 3859 0.152 grayish-white medium sandstone 1 3475.40 461.75 -204.04 85.16 3860 0.152 grayish-white medium sandstone 1 3475.38 462.64 -204.50 59.54 3861 5.545 grayish-white medium sandstone 1 3475.36 463.52 -204.96 54.12 3862 29.512 grayish-white medium sandstone 1 3475.35 464.42 -205.41 55.82 3863 40.183 grayish-white medium sandstone 1 3475.33 465.31 -205.86 56.60 3864 39.099 grayish-white medium sandstone 1 3475.32 466.20 -206.30 57.38 When loading discretized lithological data into the seismic interpretation area using the Jason seismic interpretation software, it is crucial to strictly adhere to the loading process based on the types of well logging curves that the software can recognize. Only then can the correct identification and accurate well-seismic relationship matching be achieved. Through practice, loading the discretized lithological data into the format shown in Table 1 ensures that its trajectory can be accurately loaded onto the seismic interpretation area, guaranteeing the accuracy of the lateral comparative analysis.

[0034] The saved well depth-time relationship is loaded onto the already loaded drilled lithology curve, assigning seismic time information to the horizontal section of the horizontal well. The discretized lithology curve and total hydrocarbon display are then projected onto the seismic profile and interpretation result profile. Based on the profile size, the appropriate display scale and colors corresponding to different lithologies are adjusted. Referring to commonly used logging colors, the colors for lithology logging on the seismic profile are defined: medium-coarse sandstone: yellow; fine sandstone: orange; mudstone: earthy; total hydrocarbons in gas logging are represented by a red line. Figure 2 .

[0035] During horizontal drilling of the horizontal section of a horizontal well, if mudstone or poor drilling visibility is encountered, it is necessary to analyze the rationality of the horizontal section trajectory based on relevant data, and whether the existing horizontal length needs to be lengthened or modified to meet design requirements. Leveraging the high lateral resolution of seismic data, and using known well response models for the local seismic area, changes in the trajectory can be predicted based on variations in the seismic wave group of the horizontal section of the horizontal well.

[0036] like Figure 2 As shown in the upper part, the latter half of the horizontal section encountered mudstone. According to conventional seismic data, the seismic waveform weakened, and the tectonic trend showed a slight downward change. It was determined that the probability of encountering mudstone was relatively high, and drilling could be terminated.

[0037] In addition, other earthquake interpretation results can be referenced, such as Figure 2 The lower half shows the pre-stack gas-bearing prediction results. During the drilling process in the horizontal section, mudstone interlayers appeared in the middle, indicating a deterioration in the prediction effect. This result can also effectively identify changes in lithology and gas-bearing strata, and by spatially and three-dimensionally judging changes in lithology near the horizontal section in the time domain, it can provide good guidance for subsequent work operations.

[0038] By comprehensively analyzing various seismic interpretation results, the drilling trajectory is optimized, and the drilling rate of reservoirs and gas-bearing features is improved. This method effectively solves the problem of rapid trajectory analysis when encountering mudstone and other special lithologies during the drilling process of horizontal wells.

Claims

1. A method for rapid optimization and adjustment of horizontal well trajectory, characterized in that, Includes the following steps: 1) Obtain logging data from horizontal well pilot wells drilled specifically for probing the geological conditions of the target well's formation; load the logging data into the seismic interpretation work area to obtain the time-depth relationship and save it; the time-depth relationship is the correspondence between depth data in the logging data and time data in the seismic data; 2) After backfilling the pilot well, sidetrack the horizontal well and obtain logging data of the horizontal section. The logging data includes at least lithological data. Load the logging data into the seismic interpretation area and obtain the well trajectory curve on the seismic interpretation area. The well trajectory curve includes the corresponding lithological changes. 3) Load the time-depth relationship of this well onto the well trajectory curve and assign seismic time information to the horizontal segment; display the well trajectory curve on the seismic profile in the time domain; 4) Optimize and adjust the horizontal well trajectory based on the current drilling conditions reflected in the logging curves and the corresponding seismic response; In step 2), when loading the logging data into the seismic interpretation area, the north-south and east-west displacements are also loaded; the logging data also includes total hydrocarbon data; In step 3), the total hydrocarbon trajectory curve during well operation is also displayed on the seismic profile in the time domain; In step 2), before loading the logging data into the seismic interpretation area, the lithology is discretized, different colors are assigned to different lithologies, and the discretized lithology curves with different colors are displayed on the seismic profile.

2. The method for rapid optimization and adjustment of horizontal well trajectory according to claim 1, characterized in that, The seismic profile also includes the interpretation results profile.

3. The method for rapid optimization and adjustment of horizontal well trajectory according to claim 2, characterized in that, In steps 1) and 2), the well logging data and well logging data are loaded into the seismic interpretation work area using commercial seismic interpretation software Landmark or Jason.

4. The method for rapid optimization and adjustment of horizontal well trajectory according to claim 1, characterized in that, The depth data includes depth sounding and vertical depth.

5. The method for rapid optimization and adjustment of horizontal well trajectory according to claim 1, characterized in that, The time data is for two-way trips.

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