Tracking-while-drilling comparative analysis method based on stratum true thickness and related device

Abstract

The invention discloses a real stratum thickness-based tracking-while-drilling comparative analysis method and a related device, and belongs to the technical field of stratum distribution in the field of oil exploration. The method comprises the following steps: preprocessing well trajectory data; the preprocessed well trajectory data are loaded to stratigraphic contrast software and adjusted to be in a vertical depth mode; then completing correction of a well trajectory and a stratigraphic dip angle in a vertical depth mode to obtain the true thickness of the stratum; and finally, obtaining a stratigraphic contrast graph through the stratum true thickness, and carrying out stratigraphic contrast analysis. According to the method, depth correction is carried out on the well trajectory and the stratigraphic dip angle of the horizontal well, a reliable research concept is provided for real-time stratigraphic division and real-time stratigraphic comparison in the horizontal well geosteering drilling while-drilling interpretation process, and a research method for determining the true thickness of the stratum in horizontal well while-drilling tracking through analysis and correction of the well trajectory and stratigraphic mode relation is formed.

Description

Technical Field

[0001] The present invention belongs to the technical field of stratum distribution in the field of petroleum exploration, and relates to a method for tracking and comparing stratum true thickness while drilling and a related device. Background Art

[0002] The Kekeya condensate gas field is located at the northern foot of the Kunlun Mountains on the southwestern edge of the Tarim Basin. Its structure lies within the anticline belt of the southwestern margin of the Tarim Basin, with a near-east-west trend. It is a nearly symmetrical short-axis anticline with a slightly steeper northern flank and a more gradual southern flank. Depletion-based development began in 1989. Due to weak edge water energy and rapid pressure drop, the formation pressure is currently low, with severe retrograde condensation. Natural gas recovery is high, but oil recovery is low, placing the field in the late stages of development. The construction of a gas storage facility can improve condensate and rim oil recovery, achieving seasonal peak-shaving and ensuring winter supply, with significant economic and social benefits. Because horizontal wells have a larger contact area with the condensate reservoir, horizontal injection and production wells can address formations where vertical wells have yielded suboptimal or even failed injection and production. Compared to vertical wells, horizontal wells offer better borehole-reservoir contact and can provide higher oil and gas production. Therefore, determining the true formation thickness and comparing it with surrounding wells to determine the well trajectory's position within the formation is crucial.

[0003] With advancements in drilling technology, horizontal well drilling techniques are continuously improving. Various equipment for horizontal well development has been commissioned, and research institutions have made progress in horizontal well development. However, because the theories and experience of drilling and tracking-while-drilling techniques are largely based on vertical wells, many interpreters' understanding of the contact relationship between horizontal wells and formations remains constrained by traditional vertical well interpretation experience. They also lack a systematic and comprehensive understanding of the principles of true formation thickness correction for horizontal wells. Consequently, research in horizontal well geosteering techniques and other areas remains in its infancy, seriously hindering technological progress in horizontal well development. Given the current situation, fully understanding the differences between horizontal and vertical well formation models and confirming true formation thickness is crucial and holds immense research value. Summary of the Invention

[0004] The purpose of the present invention is to solve the technical problem that the conventional drilling tracking and comparative analysis method is difficult to confirm the true thickness of the formation, and to provide a drilling tracking and comparative analysis method based on the true thickness of the formation and related devices.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for tracking and comparing formation true thickness while drilling, comprising the following steps:

[0007] Preprocessing the well trajectory data;

[0008] Load the pre-processed well trajectory data into the formation comparison software and adjust it to vertical depth mode;

[0009] In vertical depth mode, the well trajectory and formation dip angle are corrected to obtain the true formation thickness;

[0010] The formation comparison map is obtained through the true thickness of the formation, and the formation comparison analysis is carried out.

[0011] In a second aspect, the present invention provides a system for tracking and comparing formation true thickness while drilling, comprising:

[0012] A preprocessing module, used for preprocessing the well trajectory data;

[0013] A mode adjustment module is used to load the pre-processed well trajectory data into the formation comparison software and adjust it to the vertical depth mode;

[0014] The correction module is used to complete the correction of well trajectory and formation dip in vertical depth mode to obtain the true thickness of the formation;

[0015] The analysis module is used to obtain a stratigraphic comparison map through the true thickness of the stratigraphic layer and perform stratigraphic comparison analysis.

[0016] In a third aspect, the present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0017] In a fourth aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention discloses a method and related device for tracking and comparing formation true thickness while drilling. The method first pre-processes the well trajectory data to artificially correct the influence of formation dip. After the well trajectory data is pre-processed according to a new reference system, it is loaded into the formation comparison software and the correction of the well trajectory and formation dip is completed in the vertical depth mode. Not only is the consistency of formation thickness comparison enhanced, but the morphological characteristics of the well logging curve GR are also corrected. The comparability of the well logging curves of horizontal wells and adjacent vertical wells is significantly enhanced. By comparing the formation thickness and the well logging curve, the presence of formation omissions and duplications in the horizontal well is analyzed, thereby identifying faults. This is difficult to achieve in the previous horizontal well tracking and comparison of formations. By performing depth correction on the horizontal well trajectory and formation dip, the present invention provides a reliable research concept for real-time formation division and real-time formation comparison during the drilling interpretation of horizontal well geosteering drilling, forming a research method for analyzing and correcting the relationship between the well trajectory and formation pattern to confirm the true thickness of the formation in horizontal well tracking while drilling. This method successfully introduces a transformed reference frame to eliminate the influence of formation dip. This method improves the previous situation in which horizontal well tracking while drilling in piedmont lithologic condensate gas reservoirs could only be performed by correcting well trajectories within formation comparison software. Now, it incorporates formation dip correction to enable comparative analysis of true formation thickness, restoration of well log morphological characteristics, and fault identification. This method provides a technical method for eliminating formation dip within formation comparison software, enabling accurate formation comparison in horizontal well tracking while drilling. This not only provides effective insights and methods for horizontal well tracking while drilling in piedmont lithologic condensate gas reservoirs, but also lays the foundation for research into geosteering while drilling interpretation for horizontal wells. It also enables further research on wellbore trajectory control, thereby improving reservoir encounter rates and drilling efficiency in horizontal wells and reducing engineering risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 is a flow chart of the method of the present invention;

[0022] Figure 2 is a schematic diagram of the system of the present invention;

[0023] Figure 3 This is a schematic diagram of vertical well section depth correction according to an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of depth correction for a horizontal section of a stratum encountered in drilling below a deflection point according to an embodiment of the present invention;

[0025] Figure 5Schematic diagram of depth correction of a horizontal section of a well trajectory from a high position to a low position in a structure according to an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of depth correction of a horizontal section of a well trajectory from a low position to a high position in a structure according to an embodiment of the present invention;

[0027] Figure 7 Schematic diagram of the horizontal segment depth correction process according to an embodiment of the present invention;

[0028] Figure 8 It is the overall technical roadmap of the embodiment of the present invention;

[0029] Figure 9 This is a schematic diagram showing stratum comparison by vertical depth according to an embodiment of the present invention;

[0030] Figure 10 This is a schematic diagram showing formation comparison after the well trajectory is corrected according to an embodiment of the present invention;

[0031] Figure 11 This is a schematic diagram showing formation comparison between true thickness and vertical depth after correcting well trajectory according to an embodiment of the present invention;

[0032] Figure 12 It is a schematic diagram of the computer device structure of the present invention. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0035] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0036] In the description of the embodiments of the present invention, it should be noted that if the terms "upper," "lower," "horizontal," "inner," etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the inventive product is typically placed when in use. These terms are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0037] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0038] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0039] In view of the defects and shortcomings of the existing horizontal well tracking while drilling research methods in the research of gas reservoir areas with poor quality of piedmont seismic data, in order to fill the gap in the method of determining the true thickness of the formation for comparative analysis in the horizontal well tracking while drilling in piedmont lithologic condensate gas reservoirs, this application has developed a method for determining the true thickness of the formation for comparative analysis in the horizontal well tracking while drilling in piedmont lithologic condensate gas reservoirs. This method can accurately analyze the true thickness of the formation encountered by the horizontal well, and determine the exact position of the well trajectory in the formation by comparing and analyzing the true thickness with the surrounding wells, thereby guiding the dynamic adjustment of the well trajectory during the drilling process.

[0040] The most critical task for horizontal well tracking while drilling is to understand the relationship between the well trajectory and the target formation—that is, the spatial relationship between the well trajectory and the target formation, such as its approximate location above, below, or within the formation. To minimize uncertainty in formation evaluation, a formation model can be constructed by integrating multiple information sources to determine the relationship between the well trajectory and the formation. This is a crucial task when limited data is available, and it greatly compensates for the lack of well logging data. When interpreting vertical wells, a precise geological model is rarely established. This is because the geological model is often relatively simple, and the interpreter already has a geological model of the target formation in mind during interpretation. Therefore, reservoir oil content evaluation and other tasks can be performed without a precise geological model. Furthermore, analyzing the relationship between the well trajectory and the formation is essential for horizontal well interpretation. In contrast to vertical wells, the same logging curve characteristics may sometimes correspond to different target formations, and even the same target formation may have different curve characteristics. This applies to both horizontal well interpretation and numerical simulation. The first step is to understand the relationship between well trajectories and formations. To facilitate inter-well comparisons, well trajectory analysis is crucial before constructing a formation model. Horizontal wells, affected by well inclination, can result in significant discrepancies between measured and vertical depths. Therefore, depth correction is fundamental to linking horizontal well data with data from adjacent highly deviated and vertical wells.

[0041] The present invention is described in further detail below with reference to the accompanying drawings:

[0042] See also Figure 1 The embodiment of the present invention discloses a method for tracking and comparing formation true thickness while drilling, comprising the following steps:

[0043] S1, preprocessing of well trajectory data;

[0044] S2, loading the pre-processed well trajectory data into the formation comparison software and adjusting it to the vertical depth mode;

[0045] S3, complete the correction of well trajectory and formation dip in vertical depth mode to obtain the true thickness of the formation;

[0046] S4, obtain a stratigraphic comparison map through the true thickness of the stratigraphic layer and conduct stratigraphic comparison analysis.

[0047] It should be noted that the embodiments of the present invention, by performing depth correction on horizontal well trajectories and formation inclination, provide a reliable research concept for real-time stratigraphic delineation and correlation during geosteering while-drilling interpretation of horizontal wells. This method develops a research method for analyzing and correcting the relationship between well trajectories and formation patterns to confirm true formation thickness during horizontal well tracking while-drilling. This method successfully introduces a transformed reference system to eliminate the influence of formation inclination. This method improves the previous situation in which horizontal well tracking while-drilling in piedmont lithologic condensate gas reservoirs could only correct well trajectories within formation correlation software. This method now incorporates formation inclination correction to enable comparative analysis of true formation thickness, restoration of well log morphological features, and fault identification. This method provides a technical method for eliminating formation inclination within formation correlation software, enabling accurate formation correlation during horizontal well tracking while-drilling. This method not only provides an effective approach and method for horizontal well tracking while-drilling in piedmont lithologic condensate gas reservoirs, but also lays a foundation for geosteering while-drilling interpretation research for horizontal wells. It also enables further research on wellbore trajectory control, thereby improving reservoir penetration rates and drilling efficiency in horizontal wells and reducing engineering risks.

[0048] In a feasible embodiment of the present invention, the pre-processing of the well trajectory data specifically includes: pre-processing the well inclination angle data of the well trajectory, and the specific calculation formula is as follows:

[0049] α correction = α + β (1)

[0050] Among them, α represents the well inclination angle; β represents the formation dip angle, which is read from the original measurement data; α 校正 The well trajectory is drilled from the high position to the low position of the formation, and the well trajectory is drilled from the low position to the high position of the formation, and the well trajectory is drilled from the low position to the high position, and the well trajectory is drilled from the low position to the high position.

[0051] In a feasible embodiment of the present invention, the correction of the well trajectory and formation dip in the vertical depth mode specifically includes:

[0052] S301, when the formation is horizontal, determining the true thickness of the formation based on the relationship between the formation encountered by drilling and the deflection point;

[0053] S302: When the formation has a dip, determine the true thickness of the formation according to the well trajectory.

[0054] It should be noted that the method for correcting formation thickness is to divide the well trajectory into several sections according to its dogleg degree (curvature: the change in well inclination angle per unit arc length). Assuming that the dogleg degree of each section is constant, since the distance between the trajectory while drilling data measurement points is short (one point per meter), it can be considered that the well inclination angle change rate of the well section between two trajectory measurement points is a constant value, and the well section above the inclination point is vertical.

[0055] In a feasible embodiment of the present invention, the S301 specifically includes the following steps:

[0056] a.See Figure 3 When the stratum encountered is above the inclination point O, the inclination depth of the upper and lower boundaries of the stratum is L A and L B Vertical depth H A and H B , then above the inclination point O, if the inclination depth L of points A and B on the vertical well section is A and L B Approximately equal to vertical depth H A and H B (Ignore the vertical well section offset), that is, the true thickness of the formation encountered is the vertical depth H A and H B The difference:

[0057] H=H B -H A =L A -L B (2)

[0058] Among them, L A is the oblique depth of the upper boundary; L B The oblique depth of the lower boundary; H A is the vertical depth of the upper boundary; H B is the vertical depth of the lower boundary;

[0059] b. See Figure 4 When the stratum encountered is below the inclination point O, the inclination depth of the upper and lower boundaries of the stratum is L A and L B Vertical depth H A and H B , assuming that the dogleg degree of the AB section is a constant, then dα / dh = constant, which can be expressed as:

[0060]

[0061]

[0062] Among them, L A is the oblique depth of the upper boundary; L B is the lower boundary depth; α represents the well inclination angle;

[0063] Take a small section dL on the AB well section and regard it as a straight line. The corresponding vertical distance dH is obtained by trigonometric function:

[0064] dH=dL·cos α (5)

[0065] Then the vertical distance between AB and the true thickness of the formation H is:

[0066]

[0067] Among them, L A is the oblique depth of the upper boundary; LB is the oblique depth of the lower boundary; α A represents the upper boundary well inclination angle; α B Indicates the lower boundary well inclination angle.

[0068] In a feasible embodiment of the present invention, the S302 specifically includes the following steps:

[0069] a. When the formation has a dip, the well trajectory goes from the high part to the low part of the structure;

[0070] See also Figure 5 The stratum encountered is below the inclination point O, and the inclination depth of the upper and lower boundaries of the stratum is L A and L B , vertical depth H A and H B , assuming the dogleg degree (curvature) of segment AB is a constant, then dα / dh = constant, expressed as:

[0071]

[0072] Among them, L A is the oblique depth of the upper boundary; L B is the oblique depth of the lower boundary; α A represents the upper boundary well inclination angle; α B represents the lower boundary well inclination angle;

[0073] Assume the closing distance of the drilling trajectory is X, then:

[0074]

[0075] Substituting (8) into (7) we get:

[0076]

[0077] Separating the variables and integrating gives:

[0078]

[0079] The closing distance difference is:

[0080]

[0081] According to the trigonometric function relationship, the true thickness of the formation is:

[0082] H=[H B -H A -tanβ(X B -X A )]cosβ (12)

[0083] Among them, H A is the vertical depth of the upper boundary; H Bis the vertical depth of the lower boundary;

[0084] Convert vertical depth and closing distance into inclined depth and well inclination angle to express:

[0085]

[0086] Among them, L A is the oblique depth of the upper boundary; L B is the oblique depth of the lower boundary; α A represents the upper boundary well inclination angle; α B Indicates the lower boundary well inclination angle.

[0087] b. When the formation has a dip, the well trajectory goes from the low part to the high part of the structure;

[0088] As attached Figure 6 As shown in the figure, the stratum encountered is below the inclination point O, and the inclination depth of the upper and lower boundaries of the stratum is L A and L B , vertical depth H A and H B , assuming that the dogleg degree (curvature) of segment AB is a constant, that is, dα / dh = constant, we have:

[0089]

[0090] Assuming the closing distance of the drilling trajectory is X, we can get:

[0091]

[0092] Substituting (8) into (7) we get:

[0093]

[0094] Separating the variables and integrating gives:

[0095]

[0096] The closing distance difference is:

[0097]

[0098] According to the trigonometric function relationship, the true thickness H of the formation is:

[0099] H=[H V -H A -tanβ(X B -X A )]cosβ (12)

[0100] Among them, H A is the vertical depth of the upper boundary; H B is the vertical depth of the lower boundary;

[0101] Convert vertical depth and closing distance into inclined depth and well inclination angle to express:

[0102]

[0103] Among them, L A is the oblique depth of the upper boundary; L B is the oblique depth of the lower boundary; α A represents the upper boundary well inclination angle; α B Indicates the lower boundary well inclination angle.

[0104] In summary:

[0105] True thickness of formation = [H B -H A -tanβ(X B -X A )]cosβ

[0106]

[0107] It should be noted that:

[0108] When the stratum is horizontal, the stratum dip angle β=0;

[0109] When the well trajectory moves from a high position to a low position in the structure, the formation dip angle β takes a positive value;

[0110] When the well trajectory moves from a low position to a high position of the structure, the formation dip angle β takes a negative value.

[0111] Current mainstream formation comparison software (such as Resform) has two display modes: oblique depth mode and vertical depth mode. Horizontal well tracking comparison in oblique depth mode will magnify the formation thickness, which is not conducive to formation comparison. Usually, the vertical depth mode is used to correct the influence of well trajectory, but the factor of formation dip is not corrected. When the formation dip is small, the impact on the true formation thickness is small, and the formation comparison tracking effect can still meet research needs. However, as the formation dip increases, the formation thickness is distorted, and the shape of the logging curve also undergoes significant changes, making formation comparison work impossible.

[0112] When the seismic and adjacent well imaging logging data clearly indicate the structural formation dip, the relationship between the well trajectory and the formation is established through the above model. The well trajectory data is pre-processed before the software is loaded to artificially correct the influence of the formation dip. Figure 7 a and Figure 7b It can be obtained that the reference system of the well trajectory's inclination and formation dip is the horizontal ground. The vertical depth mode of the formation comparison software also takes the horizontal ground as the reference system, and projects the stratum encountered by the well trajectory onto the vertical line of the horizontal ground to correct the well trajectory. However, the thickness after projection is still affected by the formation dip. For ease of understanding, the pattern diagram is rotated by a certain angle, and the formation dip is rotated to the horizontal. The reference system of the well trajectory in the vertical depth mode of the formation comparison software is still the horizontal plane, but it is transformed from the horizontal ground to the horizontal formation. At this time, the formation becomes horizontal, and the influence of the formation dip can be ignored, so as to achieve the correction of the formation dip. The reference system of the well trajectory is transformed from the horizontal ground to the horizontal formation, and the calculation method of the well trajectory's inclination changes. By attaching Figure 7 According to the recognized model, the well inclination angle from the high position to the low position of the well trajectory only needs to be subtracted from the formation dip angle, and the well inclination angle from the low position to the high position needs to be added to the formation dip angle, and the well inclination angle of the well trajectory in the new reference system can be obtained. The well trajectory correction can be completed by loading it into the formation comparison software.

[0113] Due to the change of the reference system, the depth and vertical depth data scales will become invalid, but the relative thickness of the vertical depth scale is still valid, reflecting the true thickness of the formation. After the well trajectory data is processed in advance according to the new reference system, it is loaded into the formation comparison software and the correction of the well trajectory and formation dip is completed in the vertical depth mode. Not only the comparison consistency of the formation thickness is enhanced, the morphological characteristics of the logging curve GR are also corrected, and the comparability of the logging curves of the horizontal well and the adjacent vertical well is significantly enhanced. By comparing the formation thickness and the logging curve, it is found that there are missing and repeated formations in the horizontal well, so as to identify faults. This was difficult to achieve in the previous horizontal well tracking formation comparison. Therefore, the results of the correction of the well trajectory and formation dip in this application are highly consistent with the comparison characteristics of the adjacent wells, and the research results are accurate and reasonable.

[0114] In a feasible embodiment of the present invention, the performing of formation comparative analysis specifically includes: performing formation comparative analysis and identifying faults through formation comparison diagrams in combination with morphological features of well logging curves.

[0115] See also Figure 2 The embodiment of the present invention discloses a system for tracking and comparing formation true thickness while drilling, comprising:

[0116] A preprocessing module, used for preprocessing the well trajectory data;

[0117] A mode adjustment module is used to load the pre-processed well trajectory data into the formation comparison software and adjust it to the vertical depth mode;

[0118] The correction module is used to complete the correction of well trajectory and formation dip in vertical depth mode to obtain the true thickness of the formation;

[0119] The analysis module is used to obtain a stratigraphic comparison map through the true thickness of the stratigraphic layer and perform stratigraphic comparison analysis.

[0120] See also Figure 12 An embodiment of the present invention discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for tracking and comparing the formation true thickness while drilling are implemented.

[0121] An embodiment of the present invention discloses a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the steps of the method for tracking while drilling and comparative analysis based on true formation thickness are implemented.

[0122] Example:

[0123] See also Figure 8 The embodiment of the present invention provides a method for tracking and comparing formation true thickness while drilling, which specifically includes the following steps:

[0124] Step 1: As attached Figure 7 and attached Figure 9 The well trajectory and formation relationship model is shown in the figure. Taking the B horizontal well trajectory from the low part to the high part of the structure as an example, the well trajectory data is sorted. The well inclination angle data of the well trajectory is preprocessed:

[0125] α 校正 =α+β

[0126] Among them, α represents the well inclination angle, β represents the formation dip angle, which is read from the original measurement data. 校正 Indicates the well inclination angle after correction.

[0127] Step 2: Replace the corrected well trajectory data into the B horizontal well trajectory, and display the formation comparison software in vertical depth mode to obtain the attached Figure 10 .

[0128] Step 3: Calculate the thickness of each layer according to the calculation formula of the true thickness of the formation and mark it on the attached Figure 11 The stratigraphic comparison diagram in the well logging curve is combined with the morphological characteristics of the well logging curve to conduct stratigraphic comparison analysis, and the missing and repeated stratigraphic layers caused by faults can be identified:

[0129]

[0130] Among them, α A and α B represents the well inclination angle, β represents the formation dip angle and takes a negative value, L A and L B Indicates oblique depth.

[0131] Step 4: After completing the well trajectory and formation dip correction processing through the above steps, the resulting formation comparison map can be used for formation comparison analysis and fault identification.

[0132] Attachment Figure 9 The stratigraphic comparison diagram without stratigraphic dip correction and the stratigraphic comparison diagram calculated by the method provided by this patent are shown. Figure 11 The calculation data is derived from actual downhole measurement data, from which it can be clearly observed that the method provided by this application not only enhances the consistency of formation thickness comparison, but also significantly improves the comparability of logging curves between horizontal wells and adjacent vertical wells. Furthermore, by comparing formation thickness and logging curves, it is possible to analyze the presence of formation gaps and duplications in horizontal wells, thereby identifying faults. This is difficult to achieve with previous formation comparison while drilling tracking in horizontal wells. Therefore, the method provided by this application is more accurate and effective.

[0133] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0134] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0135] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0136] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for tracking and comparing formation true thickness while drilling, characterized in that: The following steps are involved: Preprocessing the well trajectory data; Load the pre-processed well trajectory data into the formation comparison software and adjust it to vertical depth mode; In vertical depth mode, the well trajectory and formation dip angle are corrected to obtain the true formation thickness; The formation comparison map is obtained through the true thickness of the formation, and the formation comparison analysis is carried out.

2. The method for tracking and comparing formation true thickness while drilling according to claim 1 is characterized in that: The preprocessing of the well trajectory data specifically includes: preprocessing the well inclination angle data of the well trajectory. The specific calculation formula is as follows: α 校正 ＝α+β (1) Among them, α represents the well inclination angle; β represents the formation dip angle, which is read from the original measurement data; α 校正 Indicates the well inclination angle after correction.

3. The method for tracking and comparing formation true thickness while drilling according to claim 1 is characterized in that: The correction of the well trajectory and formation dip in the vertical depth mode specifically includes: S301, when the formation is horizontal, determining the true thickness of the formation based on the relationship between the formation encountered by drilling and the deflection point; S302: When the formation has a dip, determine the true thickness of the formation according to the well trajectory.

4. The method for tracking and comparing formation true thickness while drilling according to claim 3 is characterized in that: The S301 specifically includes the following steps: a. When the stratum encountered is above the deflection point O, the calculation formula for the true thickness of the stratum H is as follows: H=H B -H A =L A -L B (2) Among them, L A is the oblique depth of the upper boundary; L B The oblique depth of the lower boundary; H A is the vertical depth of the upper boundary; H B is the vertical depth of the lower boundary; b. When the stratum encountered is below the deflection point O, assuming the dogleg angle of the AB section is a constant, then dα / dh = constant, expressed as: Among them, L A is the oblique depth of the upper boundary; L B is the lower boundary depth; α represents the well inclination angle; Take a small section dL on the AB well section and regard it as a straight line. The corresponding vertical distance dH is obtained by trigonometric function: dH=dL·cosα (5) Then the true thickness of the formation H is: Among them, L A is the oblique depth of the upper boundary; L B is the oblique depth of the lower boundary; α A represents the upper boundary well inclination angle; α B Indicates the lower boundary well inclination angle.

5. The method for tracking and comparing formation true thickness while drilling according to claim 3 is characterized in that: The S302 specifically includes the following steps: When the well trajectory goes from a high part to a low part of the structure or from a low part to a high part of the structure, the stratum encountered is below the inclination point O. Assuming the dogleg degree of the AB section is a constant, then dα / dh = constant, which can be expressed as: Among them, L A is the oblique depth of the upper boundary; L B is the oblique depth of the lower boundary; α A represents the upper boundary well inclination angle; α B represents the lower boundary well inclination angle; Assume the closing distance of the drilling trajectory is X, then: Substituting (8) into (7) we get: Separating the variables and integrating gives: The closing distance difference is: According to the trigonometric function relationship, the true thickness of the formation is: H=[H B -H A -tanβ(X B -X A )]cosβ (12) Among them, H A is the vertical depth of the upper boundary; H B is the vertical depth of the lower boundary; Convert vertical depth and closing distance into inclined depth and well inclination angle to express: Among them, L A is the oblique depth of the upper boundary; L B is the oblique depth of the lower boundary; α A represents the upper boundary well inclination angle; α B Indicates the lower boundary well inclination angle.

6. The method for tracking and comparing formation true thickness while drilling according to claim 5 is characterized in that: When the well trajectory moves from a high position to a low position of the structure, the formation dip angle β takes a positive value; when the well trajectory moves from a low position to a high position of the structure, the formation dip angle β takes a negative value.

7. The method for tracking and comparing formation true thickness while drilling according to claim 1 is characterized in that: The stratigraphic comparative analysis specifically includes: performing stratigraphic comparative analysis and identifying faults through stratigraphic comparative maps in combination with morphological features of well logging curves.

8. A system for tracking and comparing formation true thickness while drilling, characterized in that: include: A preprocessing module, used for preprocessing the well trajectory data; A mode adjustment module is used to load the pre-processed well trajectory data into the formation comparison software and adjust it to the vertical depth mode; The correction module is used to complete the correction of well trajectory and formation dip in vertical depth mode to obtain the true thickness of the formation; The analysis module is used to obtain a stratigraphic comparison map through the true thickness of the stratigraphic layer and perform stratigraphic comparison analysis.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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