A method for improving the sweet spot drilling rate of horizontal wells using seismic-geological integration in volcanic formations

Abstract

The present invention relates to the field of petroleum geology and is a method for improving the sweet spot drilling rate of horizontal wells by integrating seismic and geological methods in volcanic formations. The method comprises: basic data compilation, reservoir sweet spot identification, reservoir sweet spot inversion, fine velocity field construction, depth domain inversion modeling, model verification and correction, and geological guidance while drilling. The method for improving the sweet spot drilling rate of horizontal wells by integrating volcanic formation geology into the present invention is systematic and comprehensive. It can effectively improve the structural interpretation accuracy of volcanic formations with complex lithologic combinations, predict the distribution of interlayer tight oil sweet spots, reduce errors in horizontal well design, and reduce the number of adjustments during drilling. It can better optimize drilling trajectories while integrating engineering technologies, thereby improving the sweet spot drilling rate and has great application potential in oilfield development.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum geology, and is a method for improving the sweet spot drilling rate of horizontal wells through the integration of volcanic rock formation seismic geology. Background Art

[0002] During oilfield development, horizontal well development technology is generally used to target thin, tight oil reservoirs developed within large volcanic formations. Improving the sweet spot drilling rate of horizontal wells in tight oil layers is undoubtedly a key technology for achieving effective reservoir utilization. Generally speaking, tight oil reservoirs sandwiched between volcanic formations have good lateral continuity and a single lithology, primarily referring to tuff reservoirs. The sweet spot physical properties and oil content are good, but the sweet spot changes rapidly laterally. The thick, high-velocity volcanic formations overlying the reservoirs vary rapidly in lateral thickness, and variations in seismic velocity lead to significant differences in the actual structural morphology of the time-domain and depth-domain seismic profiles, resulting in relatively large errors in horizontal well design. The underlying basalt interface also experiences rapid lateral structural fluctuations, and failure to make timely adjustments during drilling can lead to layer breakage, significantly impacting the drilling rate of horizontal wells. Existing solutions to this problem include: ① Inversion prediction of reservoir sweet spots using mainstream seismic interpretation software such as GeoEast, Landmark, and Geoframe relies heavily on the number of vertical wells drilled, failing to effectively identify thin sweet spots in the early stages of development. ② Establishing an average velocity field is the most common method for converting time-domain data into the depth domain, but it cannot address the large structural errors caused by rapid lithofacies changes in volcanic formations. ③ Logging-while-drilling geosteering, the primary guidance technology for horizontal well drilling, suffers from significant lag when faced with rapid dip changes in volcanic formations. Volcanic formations present more complex challenges, and currently, no more adaptable method exists to improve drilling efficiency. Summary of the Invention

[0003] The present invention provides a method for improving the sweet spot drilling rate of horizontal wells by integrating seismic geology with volcanic formations, which overcomes the shortcomings of the above-mentioned existing technologies and can effectively solve the problems that affect the drilling rate of horizontal wells, such as discontinuous development of sweet spots, large structural errors, and rapid changes in formation inclination.

[0004] The technical solution of the present invention is achieved through the following measures: a method for improving the sweet spot drilling rate of horizontal wells by integrating seismic geology with volcanic formations, which is carried out according to the following steps:

[0005] S1, basic data collation, collect data of wells drilled in the study area and seismic profile data in the study area, conduct velocity field construction, and identify the key factors that restrict the sweet spot drilling rate of horizontal wells in the study area;

[0006] S2, reservoir sweet spot determination, the reservoir is comprehensively classified using the oil content and physical properties of the cores from the system coring wells, and the correlation between the core physical properties and the well logging curves is used to find the characteristic curve that can distinguish the high and low oil content of the lithology;

[0007] S3, reservoir sweet spot inversion, using SMI software to perform well logging curve and phase-controlled waveform indication technology inversion;

[0008] S4, fine velocity field construction, uses a velocity field construction method with multiple information constraints to improve the accuracy of velocity fields in complex lithologic sedimentary formations;

[0009] S5, depth domain inversion modeling, using GeoEast software to combine the time domain sweet spot inversion data volume with the fine velocity field data to convert it into a depth domain sweet spot inversion data volume to establish an integrated seismic-geological model;

[0010] S6, model verification and correction, selecting horizontal wells that are not involved in establishing the seismic-geological integration model to conduct verification, analysis and correction of the seismic-geological integration model;

[0011] S7, geosteering while drilling, based on the seismic-geological integration model, selects the logging curves while drilling that can best distinguish small layers and have good well comparison, establishes a small layer comparison mode for tracking while drilling, and guides the drilling of horizontal wells in the study area.

[0012] The following are further optimizations and / or improvements to the above technical solutions:

[0013] The specific operations of the above step S1 are:

[0014] S11, collect well logging, mud logging and core test data of the wells drilled in the study area to determine the development characteristics and lateral variation patterns of the reservoir sweet spots;

[0015] S12, collect basic data of the drilled wells including well coordinates, elevation, core height, and well deviation data, and perform layered interpretation;

[0016] S13, time-depth calibration, horizon interpretation, and velocity field construction are performed on the seismic profiles in the study area. Combined with the actual drilling tracking process, the error value of the horizontal well design target and the change value of the formation inclination during drilling are determined to identify the key factors that restrict the sweet spot drilling rate of horizontal wells.

[0017] In the above step S2, when comprehensively classifying the reservoirs, a longitudinal reservoir division is performed on the well logging curve to determine a reasonable classification of the reservoirs, and the lithologic and electrical characteristics are compared.

[0018] In the above step S3, the logging curves of 5 to 10 wells in the study area are selected for well-seismic inversion, the morphology of the reservoir sweet spot layer is inverted in plane and section, and the well pattern is arranged in the area where the sweet spot layer is continuously developed.

[0019] In the above step S4, the velocity field construction method with multi-information constraints is to perform velocity field construction in a multi-information constraint manner using velocity spectrum, well logging data, seismic data, and horizon interpretation data.

[0020] The specific operations of the above step S7 are:

[0021] S71: The reservoir in the study area is subdivided into multiple layers from top to bottom, and the interface of the layers is used as a marker for while-drilling comparison, approaching layer by layer to ensure that the horizontal well trajectory hits the target;

[0022] S72: During drilling of horizontal wells, select adjacent vertical wells to make a comparison map of small layers while drilling, and determine the well trajectory position in real time;

[0023] S73: Select the corresponding interface curve points in the target frame to calculate the vertical depth, true formation thickness, and formation dip. Combined with the formation dip provided by the integrated seismic-geological model, the actual drilling well inclination is adjusted to match the formation dip, and the well trajectory is controlled to drill within the sweet spot layer.

[0024] In the above step S7, the logging while drilling curve is one or both of a gamma-ray logging while drilling curve and a resistivity logging while drilling curve.

[0025] This comprehensive and systematic method can effectively predict the distribution of 5-meter-thin sweet spots, enabling precise velocity field construction with a depth domain error of less than 5 meters. This method establishes a geological model for horizontal well design and guidance, effectively improving the accuracy of structural interpretation of complex volcanic formations and increasing the sweet spot drilling rate in horizontal wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Attachment Figure 1 The present invention provides a flow chart of a method for improving the sweet spot drilling rate of horizontal wells by integrating volcanic formation seismic geology with the present invention.

[0027] Attachment Figure 2 This is a cross-sectional view of the tight oil reservoir in the study area in Example 8.

[0028] Attachment Figure 3 This is the well profile diagram of the superposition of seismic and interval velocity in the study area in Example 8.

[0029] Attachment Figure 4 This is the porosity and permeability intersection classification chart for the tight oil reservoir core in Example 8.

[0030] Attachment Figure 5 This is a chart showing the relationship between the core porosity and nuclear magnetic porosity of the three types of reservoirs in Example 8.

[0031] Attachment Figure 6 This is the comprehensive classification evaluation diagram of the tight oil single well reservoir in Example 8.

[0032] Attachment Figure 7 This is the inversion technology roadmap in Example 8.

[0033] Attachment Figure 8 This is a cross-sectional diagram of the wells in the nuclear magnetic movable fluid porosity inversion in Example 8.

[0034] Attachment Figure 9 This is the seismic forward model diagram of the volcanic rock formation in the study area in Example 8.

[0035] Attachment Figure 10 This is a flow chart of the multi-information constrained fine speed field building technology in Example 8.

[0036] Attachment Figure 11 This is a cross-sectional view of the fine velocity field in Example 8.

[0037] Attachment Figure 12 This is the deep-domain NMR movable hole inversion profile in Example 8.

[0038] Attachment Figure 13 This is a schematic diagram of the completed drilling inspection in Example 8.

[0039] Attachment Figure 14 This is a comparison diagram of the small layer guided while drilling in Example 8.

[0040] Attachment Figure 15 This is a comparison diagram of the guided sub-layers while drilling in the Ma T102-5H well in Example 8.

[0041] Attachment Figure 16 This is a depth domain cross-sectional view of the movable hole inversion model of the Ma T102-5H well trajectory in Example 8.

[0042] Attachment Figure 17 This is an analysis diagram of the drilling effect of Ma T103-4H in Example 8.

[0043] Attachment Figure 18 This is an analysis diagram of the drilling effect of the Ma T102-5H in Example 8. DETAILED DESCRIPTION

[0044] The present invention is not limited to the following embodiments, and specific implementation methods can be determined based on the technical solutions of the present invention and actual conditions.

[0045] The present invention will be further described below in conjunction with the embodiments:

[0046] Example 1: The method for improving the sweet spot drilling rate of horizontal wells by integrating seismic geology with volcanic formations is carried out according to the following steps:

[0047] S1, basic data collation, collect data of wells drilled in the study area and seismic profile data in the study area, conduct velocity field construction, and identify the key factors that restrict the sweet spot drilling rate of horizontal wells in the study area;

[0048] S2, determination of reservoir sweet spots, using the oil content and physical properties of the cores from the coring wells to comprehensively classify the reservoirs. Based on the correlation between the core physical properties and the well logging curves, a characteristic curve that can distinguish between high and low oil content of lithologies is found;

[0049] S3, reservoir sweet spot inversion, using SMI software to perform well logging curve and phase-controlled waveform indication technology inversion;

[0050] S4, fine velocity field construction, uses a velocity field construction method with multiple information constraints to improve the accuracy of velocity fields in complex lithologic sedimentary formations;

[0051] S5, depth domain inversion modeling: GeoEast software is used to combine the time domain sweet spot inversion data volume with the fine velocity field data to convert it into a depth domain sweet spot inversion data volume to establish an integrated seismic-geological model;

[0052] S6, model verification and correction, selecting horizontal wells that are not involved in establishing the seismic-geological integration model to conduct verification, analysis and correction of the seismic-geological integration model;

[0053] S7, geosteering while drilling, based on the seismic-geological integration model, selects the logging curves while drilling that can best distinguish small layers and have good well comparison, establishes a small layer comparison mode for tracking while drilling, and guides the drilling of horizontal wells in the study area.

[0054] This invention establishes a systematic method for improving the penetration rate of horizontal wells, encompassing a comprehensive and integrated approach encompassing reservoir sweet spot inversion, fine velocity field construction, depth-domain inversion modeling, and geosteering while drilling. This method establishes an integrated seismic-geological model that, after calibration, achieves a high degree of agreement with the horizontal profile of the completed well. This integrated seismic-geological model serves as a platform for horizontal well design and steering, effectively improving the accuracy of structural interpretation of complex volcanic lithologic combinations, predicting the distribution of interlayer tight oil sweet spots, reducing errors in horizontal well design, and reducing the number of adjustments during drilling. This method enables better optimization of drilling trajectories while integrating engineering technologies, thereby improving the penetration rate of sweet spots.

[0055] Example 2: As an optimization of the above example, the specific operation of step S1 is as follows:

[0056] S11, collect well logging, mud logging and core test data of the wells drilled in the study area to determine the development characteristics and lateral variation patterns of the reservoir sweet spots;

[0057] S12, collect basic data of the drilled wells including well coordinates, elevation, core height, and well deviation data, and perform layered interpretation;

[0058] S13, time-depth calibration, horizon interpretation, and velocity field construction are performed on the seismic profiles in the study area. Combined with the actual drilling tracking process, the error value of the horizontal well design target and the change value of the formation inclination during drilling are determined to identify the key factors that restrict the sweet spot drilling rate of horizontal wells.

[0059] Example 3: As an optimization of the above example, in step S2, when comprehensively classifying the reservoir, a longitudinal reservoir division method is adopted on the logging curve to determine the reasonable classification of the reservoir, and the lithologic and electrical characteristics are compared.

[0060] Example 4: As an optimization of the above example, in step S3, the logging curves of 5 to 10 wells in the study area are selected for well-seismic inversion, the morphology of the reservoir sweet spot layer is inverted in the plane and section, and the well network is arranged in the area where the sweet spot layer develops continuously.

[0061] Example 5: As an optimization of the above example, in step S4, the velocity field construction method with multi-information constraints is to perform velocity field construction in a multi-information constraint manner using velocity spectrum, well logging data, seismic data, and horizon interpretation data.

[0062] Because the target layer is commonly overlain by low-velocity tuffs of the second member and high-velocity basalts of the third member, the formation thickness and volcanic facies vary rapidly vertically and horizontally, making velocity and structural determination difficult. Seismic forward modeling indicates that the thickness of the overlying high-velocity strata varies rapidly, resulting in significant deviations from the actual temporal morphology of the target layer. In this paper, a velocity field construction method using multiple information constraints, including velocity spectra, well logging data, seismic data, and stratigraphic interpretation data, effectively improves the accuracy of velocity fields in complex sedimentary formations.

[0063] Example 6: As an optimization of the above example, the specific operation of step S7 is as follows:

[0064] S71: The reservoir in the study area is subdivided into multiple layers from top to bottom, and the interface of the layers is used as a marker for while-drilling comparison, approaching layer by layer to ensure that the horizontal well trajectory hits the target;

[0065] S72: During drilling of horizontal wells, select adjacent vertical wells to make a comparison map of small layers while drilling, and determine the well trajectory position in real time;

[0066] S73: Select the corresponding interface curve points in the target frame to calculate the vertical depth, true formation thickness, and formation dip. Combined with the formation dip provided by the integrated seismic-geological model, the actual drilling well inclination is adjusted to match the formation dip, and the well trajectory is controlled to drill within the sweet spot layer.

[0067] Example 7: As an optimization of the above example, in step S7, the LWD curve is one or both of a LWD gamma curve and a LWD resistivity curve. The LWD gamma curve and the LWD resistivity curve have the best effect when used together.

[0068] LWD curve selection is based on the principle of distinguishing sub-layers and ensuring good well-to-well correlation. Specifically, a logging curve that can sensitively reflect changes in formation lithology and physical properties and whose well-to-well characteristics are similar is selected. In this invention, LWD gamma-ray and LWD resistivity logging curves are used to establish a LWD tracking sub-layer correlation model. The preferred approach is to use both together.

[0069] Example 8: Application of the method for improving the sweet spot drilling rate of horizontal wells by integrating seismic geology with volcanic formations in the tight oil of the Niujuanhu Tiaohu Formation in the Tuha Oilfield:

[0070] S1, basic data collation: collect well logging, mud logging, and core test data of a new block in the oil field to determine the reservoir physical properties and lateral distribution changes (see Figure 2 ).like Figure 2 As shown, the reservoir profile in the study area shows that the tuff reservoir is horizontally continuous, vertically heterogeneous, and has good reservoir properties. The average porosity is 12%, the oil layer thickness is 10m to 43m, and the burial depth is 1850m to 2350m. It deteriorates as the formation moves to the edge. The reservoir type is a structural-lithologic reservoir. The basic data of the drilled wells are collected, including well coordinates, altitude, core height, well inclination data, and layer interpretation. Time-depth calibration, layer interpretation, and velocity field establishment are performed on the seismic profile. Combined with the actual drilling tracking process, the error in the horizontal well design target, the change in the formation inclination during drilling, and the change in the thickness of the sweet spot layer are determined. These are the three factors that restrict the sweet spot drilling rate of horizontal wells (see Figure 3 ).like Figure 3 As shown in the figure, the seismic and velocity superimposed profiles show that the formation dip changes rapidly. Above the target layer, low-velocity tuff of the second member and high-velocity basalt of the third member are developed. The average velocity of the basalt layer is 4800m / s, and the average velocity of the tuff layer is 3200m / s. The formation thickness and volcanic rock facies change rapidly vertically and horizontally, resulting in rapid lateral changes in the formation velocity field, making structural confirmation difficult.

[0071] S2, Determination of reservoir sweet spots: Using the cores from the system coring wells, three types of reservoirs are classified according to their oil content (see Figure 4 ), the classification and evaluation criteria for tight oil reservoirs are shown in Table 1. Figure 4 As shown in the figure, the oil content level of the core is well correlated with the porosity, and the lower limits of the porosity of the three types of reservoirs are divided, indicating that porosity can be used to classify reservoirs. Based on the positive correlation between the core porosity and the nuclear magnetic movable porosity, the nuclear magnetic movable pore intervals of the three types of reservoirs are divided. Figure 5 As shown, the Class I layer has NMR movable pores > 8.0%; the Class II layer has NMR movable pores 4.0% to 8.0%; the Class III layer has NMR movable pores 2.0% to 4.0%. Therefore, the Class I+II layers are determined to be the reservoir sweet spots. Figure 5As shown in the figure, the intersection scatter points of NMR movable porosity and core porosity are significantly positively correlated. When NMR movable porosity is greater than 4%, the sample points are mainly Class I and II reservoirs; when NMR movable porosity is greater than 8%, the sample points are mainly Class I reservoirs, indicating that the lower limit of NMR porosity for reservoir classification is reasonable. The vertical reservoir division is performed using NMR movable porosity on the well logging curve (see Figure 6 ).like Figure 6 As shown, the three types of reservoirs are reasonably divided, and the core and electrical characteristics are clearly compared. Type I layers are mainly distributed in the No. 3 sublayer, Type II layers are concentrated in the No. 1 oil layer, and Type III layers are mainly distributed in the No. 2 sublayer. Finally, the Type I layer + Type II layer are determined to be the tight oil sweet spot layer of the Niuquanhu Tiaohu Formation;

[0072] S3, reservoir sweet spot inversion: In step S2, it was determined that the NMR movable hole curve in the NMR logging can identify the tight oil sweet spot. The NMR movable hole and phase-controlled waveform indication technology inversion was performed using SMI software. All vertical wells (6) with NMR logging curves in this block were selected for well-seismic combined inversion (see Figure 7 ).like Figure 7 As shown in the figure, the "seismic waveform-driven structured statistical characterization" method is used to select sample wells corresponding to specific waveforms, analyze the combined structural characteristics of the logging curves, and establish a structural relationship between well and seismic. The waveform phase-controlled statistical inversion results of nuclear magnetic porosity are highly consistent with the vertical wells, effectively identifying a thin sweet spot layer of about 10 meters. The three sets of small layers are clearly distinguished vertically. The bottom No. 3 layer is a Class I layer with good lateral continuity, which is determined to be the target layer for horizontal well design (see Figure 8 ).like Figure 8 As shown, the nuclear magnetic movable fluid porosity inversion profile of the well-connected Ma101-MaL1-4-9H wells shows that the vertical well logging curve is highly consistent with the inversion profile. The bottom No. 3 layer mainly develops Type I layers with large thickness and laterally continuous distribution.

[0073] S4, fine velocity field construction: First, perform seismic forward modeling to confirm that the thickness of the overlying high-velocity strata changes rapidly, resulting in a large deviation between the time domain morphology of the target layer and the actual morphology. Then, use the velocity field construction method with multi-information constraints to improve the velocity field accuracy of complex lithologic sedimentary strata (see Figure 9 、 Figure 10 、 Figure 11 ).like Figure 9 As shown in Figure 1, the overlying wedge-shaped high-velocity basalt body will cause the horizontal interface between the lower tuff and basalt to appear as an interface dipping from left to right on the time domain seismic section, and will also cause the high point of the micro-anticline interface to shift to the left on the time domain seismic section. Figure 10 As shown in the figure, the velocity field is constructed by using multiple information constraints such as velocity spectrum, well logging data, seismic data, and stratigraphic interpretation data to improve the accuracy of the velocity field in complex lithologic sedimentary formations. Figure 11As shown in the figure, the final fine velocity field is constructed with the stable seismic reflection axis at the bottom of the Xishanyao Formation as the boundary. The velocity spectrum of the upper section + the accurate interval velocity of the well correction is combined with the high-resolution interval velocity of the lower section. From the comparison of actual drilling wells, the accuracy reaches 5m, which can greatly improve the structural accuracy and more accurately determine the dip angle of the underground strata.

[0074] S5, depth domain inversion modeling: GeoEast software is used to combine the time domain NMR movable borehole inversion data with the fine velocity field data to convert it into a depth domain NMR movable borehole inversion data volume. In the well trajectory design module of GeoEast software, this data volume serves as a design and tracking platform, i.e., a seismic-geological integrated model (see Figure 12 ).like Figure 12 As shown, the Ma T101-7H track travels within the geological model formed by the NMR movable hole inversion data volume in the depth domain, and the drilling rate is consistent with the inverted sweet spot;

[0075] S6, Model verification and correction: After the seismic-geological integrated model is completed, horizontal wells that are not involved in the modeling are selected for verification and analysis correction (see Figure 13 ).like Figure 13 As shown, Ma T103-7H was drilled in the early stages and did not utilize an integrated seismic-geology model. The horizontal section of the well was drilled for 825 m, the oil-bearing interval was 670 m, and the oil-bearing zone was drilled at an 81% rate. This included 68 m of Type I layers, 75 m of Type II layers, and 510 m of Type III layers. The average NMR movable borehole depth was 3%, with a low sweet spot drilling rate in Type I layers. The seismic profiles closely matched the actual drilling trajectory and well logging characteristics. Comprehensive analysis indicates that the established integrated seismic-geology model can serve as a platform for horizontal well design and steering.

[0076] S7, geosteering while drilling: Based on the seismic-geological integration model, reservoir lithology is distinguished by gamma and resistivity logging while drilling, and a small layer comparison mode is established while drilling tracking (see Figure 14 ).like Figure 14 As shown in the figure, through regional well-connected small layer comparison analysis, the reservoir is divided into three small layers from top to bottom according to the gamma curve characteristics. The interfaces of small layers 1, 2, and 3 are used as the mark for comparison while drilling, and they are approached layer by layer to ensure that the horizontal well trajectory is guided into the target during actual drilling. The target layer of the horizontal well is set as layer 3, and the bottom 10m to 15m of the reservoir is the target frame designed for the horizontal well. The top boundary of the target frame has low gamma and resistivity characteristics, and the bottom boundary is basalt. The main characteristics of the target frame: lithology dark gray tuff → gray tuff, low gamma → high, low resistivity → high, the bottom gray fluorescent tuff has the best oil content, thickness of 4m to 6m, high gamma value, high resistivity value (see Figure 14 When drilling a horizontal well, select adjacent vertical wells to make a comparison chart of the layers while drilling, and determine the well trajectory position in real time (see Figure 15 ).like Figure 15As shown in the figure, the horizontal well gamma and resistivity curves while drilling, combined with the lithology display, can accurately determine which sub-layer the well trajectory is in, and have a strong contrast with adjacent wells. Select the corresponding interface curve points with obvious markings in the target frame to calculate the vertical depth, true formation thickness, and formation dip. Combined with the formation dip provided by the model, the target depth of the undrilled trajectory is adjusted in time during the drilling process to match the well inclination with the formation dip, and the well trajectory is adjusted to drill in the center of the oil layer sweet spot (see Figure 15 、 Figure 16 ).like Figure 16 As shown, the large section of the well trajectory through the geological guidance while drilling passes through the 5-meter thin sweet spot, and the bottom exit position of the small section is consistent with the up-arch position of the profile stratum, which fully demonstrates that the seismic-geological integrated model of the present invention can better improve the sweet spot drilling rate of horizontal wells. Figure 17 and Figure 18 The two horizontal wells drilled using this invention demonstrate highly consistent trajectories and profiles, with drilling encounters consistent with sweet spot model predictions and accurate predictions of formation structural changes. This maximized the sweet spot drilling rate within the limits of drilling engineering technology, achieving a 77% sweet spot drilling rate in Well Ma T102-3H and an 82% sweet spot drilling rate in Well Ma T102-5H.

[0077] In summary, the method for improving the sweet spot drilling rate of horizontal wells through volcanic rock formation geological integration is systematic and comprehensive. It can effectively predict the distribution of 5-meter thin sweet spots, accurately establish a velocity field, and achieve a depth domain error of less than 5 meters. It can effectively improve the structural interpretation accuracy of volcanic rock formations with complex lithologic combinations, predict the distribution of interlayer tight oil sweet spots, reduce errors in horizontal well design, and reduce the number of adjustments during the drilling process. It can better optimize drilling trajectories while integrating engineering technologies, thereby improving the sweet spot drilling rate and has great application potential in oilfield development.

[0078] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the requirements of different situations.

[0079]

Claims

1. A method for improving the sweet spot drilling rate of horizontal wells by integrating seismic geology with volcanic formations, characterized in that Follow these steps: S1, basic data collation, collect data of wells drilled in the study area and seismic profile data in the study area, conduct velocity field construction, and identify the key factors that restrict the sweet spot drilling rate of horizontal wells in the study area; S2, reservoir sweet spot determination, the reservoir is comprehensively classified using the oil content and physical properties of the cores from the system coring wells, and the correlation between the core physical properties and the well logging curves is used to find the characteristic curve that can distinguish the high and low oil content of the lithology; S3, reservoir sweet spot inversion, using SMI software to perform well logging curve and phase-controlled waveform indication technology inversion; S4, fine velocity field construction, uses a velocity field construction method with multiple information constraints to improve the accuracy of velocity fields in complex lithologic sedimentary formations; S5, depth domain inversion modeling, using GeoEast software to combine the time domain sweet spot inversion data volume with the fine velocity field data to convert it into a depth domain sweet spot inversion data volume to establish an integrated seismic-geological model; S6, model verification and correction, selecting horizontal wells that are not involved in establishing the seismic-geological integration model to conduct verification, analysis and correction of the seismic-geological integration model; S7, geosteering while drilling, based on the seismic-geological integration model, selects the logging curves that can best distinguish small layers and have good well comparison, establishes a small layer comparison mode while drilling, and guides the drilling of horizontal wells in the study area; The specific operations of step S7 are: S71: The reservoir in the study area is subdivided into multiple layers from top to bottom, and the interface of the layers is used as a marker for while-drilling comparison, approaching layer by layer to ensure that the horizontal well trajectory hits the target; S72: During drilling of horizontal wells, select adjacent vertical wells to make a comparison map of small layers while drilling, and determine the well trajectory position in real time; S73: Select the corresponding interface curve points in the target frame to calculate the vertical depth, true formation thickness, and formation dip. Combined with the formation dip provided by the integrated seismic-geological model, the actual drilling well inclination is adjusted to match the formation dip, and the well trajectory is controlled to drill within the sweet spot layer.

2. The method for improving the sweet spot drilling rate of horizontal wells by integrating volcanic rock formation seismic geology according to claim 1 is characterized in that The specific operations of step S1 are: S11, collect well logging, mud logging and core test data of the wells drilled in the study area to determine the development characteristics and lateral variation patterns of the reservoir sweet spots; S12, collect basic data of the drilled wells including well coordinates, elevation, core height, and well deviation data, and perform layered interpretation; S13, time-depth calibration, horizon interpretation, and velocity field construction are performed on the seismic profiles in the study area. Combined with the actual drilling tracking process, the error value of the horizontal well design target and the change value of the formation inclination during drilling are determined to identify the key factors that restrict the sweet spot drilling rate of horizontal wells.

3. The method for improving the sweet spot drilling rate of horizontal wells by integrating volcanic formation seismic geology with that of claim 1 or 2, characterized in that In step S2, when comprehensively classifying the reservoir, a longitudinal reservoir division method is adopted on the well logging curve to determine a reasonable classification of the reservoir, and the lithologic and electrical characteristics are compared.

4. The method for improving the sweet spot drilling rate of horizontal wells by integrating volcanic rock formation seismic geology with that of claim 3 is characterized in that In step S3, the logging curves of 5 to 10 wells in the study area are selected for well-seismic inversion, the morphology of the reservoir sweet spot layer is inverted in plane and section, and the well pattern is arranged in the area where the sweet spot layer develops continuously.

5. The method for improving the sweet spot drilling rate of horizontal wells by integrating volcanic rock formation seismic geology with that of claim 4 is characterized in that In step S4, the velocity field construction method with multi-information constraints is to perform velocity field construction in a multi-information constraint manner using velocity spectrum, well logging data, seismic data, and horizon interpretation data.

6. The method for improving the sweet spot drilling rate of horizontal wells by integrating volcanic formation seismic geology with that of claim 1, 2, 4, or 5, characterized in that In step S7, the logging while drilling curve is one or both of a gamma-ray logging while drilling curve and a resistivity logging while drilling curve.

Images