A wellbore trajectory identification method and device based on a marker layer vertical depth card layer

Abstract

This invention discloses a wellbore trajectory identification method and device based on marker layer vertical depth, belonging to the field of oil and gas drilling technology. The method integrates actual drilling data and seismic data, formation data, and logging data from the surrounding work area to predict and invert marker layers that may be encountered during drilling, and reconstructs a planar structural map of the marker layer's burial depth. By capturing the marker layers encountered in the actual wellbore trajectory and calculating and comparing them with the vertical depth of the marker layers encountered in the preset wellbore trajectory, the downhole drill bit position is calculated and inferred, thereby achieving the identification and correction of the actual wellbore trajectory. This invention also discloses a wellbore trajectory identification device based on marker layer vertical depth. The technical solution of this invention can be used for wellbore trajectory identification during re-entry operations of old wells in new drilling operations, greatly reducing the drilling difficulty of re-entry and exploration of old wells, providing a reference for drilling process adjustments, and ultimately achieving effective plugging of old wells.

Description

Technical Field

[0001] This invention relates to the field of oil and gas drilling technology, and specifically to a wellbore trajectory identification method based on marker layer vertical depth. Background Technology

[0002] my country is a major natural gas reserve country and also a major natural gas energy consumer. Constructing underground gas storage facilities is a fundamental solution to the problem of uneven seasonal gas demand and long-term gas storage. Underground gas storage facilities are mainly divided into four types: depleted oil and gas reservoir type, aquifer type, salt cavern type, and abandoned mine type. Utilizing depleted oil and gas reservoirs to construct underground gas storage facilities is one of the most common types.

[0003] A summary of domestic and international experience in gas storage construction reveals that plugging old wells is crucial for ensuring the sealing integrity of oil and gas reservoir-type gas storage facilities. Improper handling of a single old well can have serious consequences for the construction of the gas storage facility. Currently, many abandoned old wells that do not meet the operational standards for gas storage facilities still exist in many areas of my country awaiting gas storage construction. Many of these old wells also have complex downhole conditions, such as some old wells lacking casing sealing in the gas layer section, or open-hole sections that have penetrated the upper caprock of the gas reservoir, damaging the caprock's sealing performance. Some complex old wells also have side-drilled open-hole sections, and even complex situations such as fish falling into the open-hole sections. Whether these wells can be effectively handled is crucial to the successful construction of the gas storage facility.

[0004] Old well treatment is crucial for ensuring the sealing integrity of oil and gas reservoirs; all old wells must be properly treated before formal construction can begin. Sidetracked open-hole sections within old wells require treatment, necessitating either re-drilling the original wellbore or drilling a parallel wellbore for re-entry, followed by re-sealing. During drilling, accurately determining the relative relationship between the trajectory of the new wellbore and the old well trajectory, and confirming that the wellbore trajectory is indeed that of the old well after re-entry at the pre-set target point, are critical. There is an urgent need for a wellbore trajectory identification method and device based on marker layer vertical depth detection. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned problems in the prior art and to provide a wellbore trajectory identification method and device based on marker layer vertical depth card layer, which can provide a practical and feasible technical solution for the identification of old well and new wellbore trajectory.

[0006] To address the aforementioned technical problems, this invention provides a wellbore trajectory identification method based on the vertical depth of marker layers. This method integrates actual drilling data, seismic data, stratigraphic data, and logging data from the surrounding work area to predict and invert marker layers that may be encountered during drilling. It also reconstructs a planar structural map showing the depth of the marker layers. By comparing the identification of marker layers encountered in the actual wellbore trajectory with the calculated vertical depth of marker layers encountered in the preset wellbore trajectory, the downhole drill bit position is estimated, thereby achieving the identification and correction of the actual wellbore trajectory.

[0007] Specifically, the steps include the following:

[0008] Step 1. Obtain seismic data, well logging data, and stratigraphic data for the study area;

[0009] Step 2. Process and interpret the seismic data and adjacent well data in detail, and pre-select lithological marker layers in key well sections where well trajectory identification is required;

[0010] Step 3. Perform lithology inversion on the drilled wells to understand the seismic and logging curve characteristics corresponding to various lithologies, and then perform lithology inversion prediction on the actual drilled wells;

[0011] Step 4. Perform fine processing on the seismic data volume around the actual well, extract the two-dimensional plane of the lithological marker layer, and restore the actual underground burial depth and geomorphological characteristics of each lithological marker layer;

[0012] Step 5. Using a combination of techniques such as spontaneous potential during drilling, natural gamma ray, logging during drilling, elemental logging, hand specimens of cuttings, and observation by scanning electron microscopy, as well as X-ray detection analysis to identify the mineral composition, elemental composition, and pore structure of the cuttings, determine whether a marker layer has been encountered and calculate the actual vertical depth of the marker layer encountered.

[0013] Step 6. Calculate the vertical depth of the marker layer encountered in the actual drilling and the vertical depth of the same marker layer encountered in the original wellbore. Project the two vertical depth data onto the marker layer plane for comparison. Combine the azimuth angle between the well trajectory and the original wellbore to obtain the approximate positional deviation between the actual drilling wellbore and the original wellbore, and give relevant correction suggestions.

[0014] Furthermore, in step 1, the seismic data includes three-dimensional seismic data volumes of the actual drilling area and two-dimensional seismic profiles or plan views, etc.

[0015] Furthermore, in step 1, the stratigraphic data includes planar maps of stratigraphic thickness in the actual drilled well and surrounding area, structural maps of the top and bottom surfaces, planar maps of sub-layers, standard stratigraphic lithology profiles, lithological marker layer data, stratigraphic strike and dip data, etc.

[0016] Furthermore, in step 1, the logging data includes logging data from the actual drilled well and surrounding adjacent wells.

[0017] Furthermore, in step 2, the pre-selection of lithological marker layers specifically involves: based on the lithological and logging data of the standard profiles of actual drilled wells and adjacent wells in the block, and combined with regional lithological marker layers, pre-determining the depth, lithology, and logging curve characteristics of marker layers that may be encountered during actual drilling operations on the formation profile, so as to facilitate timely identification during actual drilling.

[0018] Furthermore, in step 4, the seismic data volume around the actual drilling well is processed in detail, and the two-dimensional plane of the lithological marker layer is extracted. Combined with the top and bottom surface structural maps of the strata and sub-strata in the work area, the actual underground burial depth and geomorphological characteristics of each lithological marker layer are restored.

[0019] Furthermore, in step 6, based on the azimuth angle between the wellbore trajectory and the original wellbore, and the calculated actual vertical depth of the drilled marker layer, the actual vertical depth of the drilled marker layer, along with the vertical depth of the drilled marker layer predicted by stratigraphic inversion, is projected onto the structural planar map of the marker layer burial depth obtained by comprehensively processing seismic stratigraphic data. The characteristics of the marker layer burial depth, strike, dip angle, and layer thickness are comprehensively compared to identify the approximate location of the actual drilled wellbore trajectory and the predetermined wellbore trajectory on the same marker layer plane, and to determine whether there is any deviation.

[0020] On the other hand, embodiments of the present invention also provide a wellbore trajectory identification device based on marker layer vertical depth, comprising:

[0021] The data acquisition module is used to acquire seismic data, well logging data, and stratigraphic data of the study area.

[0022] The preprocessing module is used for fine processing and interpretation of seismic data and adjacent well data, and pre-selects lithological marker layers in key well sections where well trajectory identification is required;

[0023] The inversion prediction module is used to perform lithology inversion on drilled wells, understand the seismic and logging curve characteristics corresponding to various lithologies, and then perform lithology inversion prediction on actual drilled wells.

[0024] The two-dimensional plane extraction module is used to perform fine processing on the seismic data volume around the actual well and extract the two-dimensional plane of the lithological marker layer to restore the actual underground burial depth and geomorphological characteristics of each lithological marker layer.

[0025] The marker layer depth retrieval module is used to comprehensively analyze drilling spontaneous potential, natural gamma, logging during drilling, elemental logging, hand specimens of cuttings, and SEM observation, X-ray detection analysis to identify the mineral composition, elemental composition and pore structure of the cuttings, determine whether a marker layer has been encountered, and calculate the actual vertical depth of the marker layer encountered.

[0026] The drilling trajectory deviation correction module is used to calculate the vertical depth of the marker layer encountered in actual drilling and the vertical depth of the same marker layer encountered in the original wellbore. The vertical depth data of the two are projected onto the marker layer plane for comparison. Combined with the azimuth angle between the well trajectory and the original wellbore, the approximate positional deviation between the actual drilling wellbore and the original wellbore is obtained, and relevant correction suggestions are given.

[0027] On the other hand, embodiments of the present invention also provide a wellbore trajectory recognition system based on marker layer vertical depth, including one or more processors; a memory for storing one or more programs; the processors are configured to execute program instructions stored in the memory, and the program instructions execute the above-described wellbore trajectory recognition method based on marker layer vertical depth when they are executed.

[0028] On the other hand, embodiments of the present invention also provide a computer-readable storage medium storing a computer program, wherein the computer program, when executed by one or more processors, implements the above-described wellbore trajectory identification method based on the vertical depth of the marker layer.

[0029] The above-described technical solutions of the embodiments of the present invention have the following beneficial technical effects:

[0030] This invention, based on the refined processing and interpretation of seismic, logging, and regional geological data, establishes seismic prediction and lithological inversion prediction for marker layers encountered in actual drilling, ensuring the accuracy of marker layer detection. It combines logging tracking analysis with seismic and logging prediction, effectively analyzing formations in real time and providing timely guidance for on-site logging layer detection, thus providing a reliable guarantee for drilling safety. Through comprehensive comparative analysis of marker layer vertical depth data, this invention organically combines marker layer vertical depth comparison, wellbore trajectory tracking, and seismic and logging assistance, forming a method for identifying actual wellbore trajectories through geological layer vertical depth comparison. This invention breaks through traditional methods of wellbore trajectory identification, combining comprehensive utilization and refined processing of geological data, logging tracking, and marker layer detection analysis, enabling real-time correction and prediction, thereby better achieving wellbore trajectory identification and control. The present invention proposes a wellbore trajectory identification method based on marker layer vertical depth card layer, which can be used to identify wellbore trajectories in new drilling and old well re-entry operations, greatly reducing the drilling construction difficulty of old well re-entry and percussion, providing a reference for drilling process adjustment, and ultimately achieving effective plugging of old wellbores. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the wellbore trajectory identification method based on vertical depth of marker layers according to the present invention;

[0032] Figure 2 It predicts the lithology and logging curve characteristics of marker layers encountered during actual drilling;

[0033] Figure 3 This is a schematic diagram illustrating the application of a wellbore trajectory identification method based on marker layer vertical depth card layer. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0035] Please refer to Figure 1 This invention provides a wellbore trajectory identification method based on marker layer vertical depth, comprising the following steps:

[0036] Step 1. Obtain seismic data, adjacent well logging data, and stratigraphic data for the study area;

[0037] Step 2. Process and interpret the seismic data and adjacent well data in detail, and pre-select lithological marker layers in key well sections where well trajectory identification is required;

[0038] Step 3. Perform lithology inversion on the drilled wells to understand the seismic and logging curve characteristics corresponding to various lithologies, and then perform lithology inversion prediction on the actual drilled wells;

[0039] Step 4. Perform fine processing on the seismic data volume around the actual well, extract the two-dimensional plane of the lithological marker layer, and restore the actual underground burial depth and geomorphological characteristics of each lithological marker layer;

[0040] Step 5. Using a combination of techniques such as spontaneous potential during drilling, natural gamma ray, logging during drilling, elemental logging, hand specimens of cuttings and observation by scanning electron microscopy, X-ray detection and software analysis to identify the mineral composition, elemental composition and pore structure of the cuttings, determine whether a marker layer has been encountered and calculate the actual vertical depth of the marker layer encountered.

[0041] Step 6. Calculate the vertical depth of the marker layer encountered in the actual drilling and the vertical depth of the same marker layer encountered in the original wellbore. Project the two vertical depth data onto the marker layer plane for comparison. Combine the azimuth angle between the well trajectory and the original wellbore to obtain the approximate positional deviation between the actual drilling wellbore and the original wellbore, and give relevant correction suggestions.

[0042] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0043] The technical solution of the present invention will be further described below with reference to the embodiments and accompanying drawings:

[0044] (1) Preliminary data collection

[0045] ① Stratigraphic data: Plan view of the thickness of strata in the actual drilled well and surrounding area, top and bottom structural map, sub-layer plan view, standard lithological profile of strata, lithological marker bed data, stratum strike and dip data, etc.

[0046] ② Seismic data: 3D seismic data volume and software of the actual drilling area.

[0047] ③ Well logging data: Well logging data of actual drilled wells and surrounding adjacent wells, etc.

[0048] (2) Marker layer selection and inversion prediction

[0049] Based on the lithology and logging data of the standard profiles of actual drilled wells and adjacent wells in the block, and combined with regional lithological marker layers, the depth, lithology, and logging curve characteristics of the marker layers that may be encountered during actual drilling operations are pre-determined on the formation profile, so as to facilitate timely identification during actual drilling.

[0050] (3) Preprocessing of seismic and stratigraphic data

[0051] The seismic data volume around the actual drilling well was finely processed, and the two-dimensional plane of the lithological marker layer was extracted. Combined with the top and bottom structural maps of the strata and sub-strata in the work area, the actual underground burial depth of each lithological marker layer was restored. Figure 2 ) and landform features.

[0052] (4) Vertical depth sampling of marker layers during actual drilling

[0053] In actual operation, based on the actual drilling depth, a combination of techniques such as spontaneous potential during drilling, natural gamma ray, logging during drilling, elemental logging, hand specimens of cuttings and observation by scanning electron microscopy, X-ray detection and software analysis to identify the mineral composition, elemental composition and pore structure of the cuttings is used to determine whether a marker layer has been encountered and to calculate the vertical depth of the marker layer encountered.

[0054] (5) Determining the position of the actual drill bit

[0055] In actual operation, based on the azimuth angle between the well trajectory and the original wellbore, and the calculated actual vertical depth of the drilled marker layer, this is projected along with the vertical depth of the drilled marker layer predicted by stratigraphic inversion onto the structural plan view of the marker layer burial depth obtained by comprehensively processing seismic stratigraphic data. Figure 3 By comprehensively comparing the characteristics of the marker layer, such as its burial depth, strike, dip angle, and thickness, the approximate location of the actual drilled well trajectory and the predetermined well trajectory on the same marker layer plane can be identified, and it can be determined whether there is any deviation. Figure 3This invention describes a method for identifying the trajectory of a drilled well by comparing the vertical depth of the same marker layer encountered in actual drilling with that encountered in the original wellbore, and projecting this information onto a structural plan view of the marker layer depth obtained by comprehensively processing seismic stratigraphic data. The method is briefly illustrated below. The diagram below is a structural plan view of the stratigraphic structure reconstructed from seismic data, which reflects the actual burial topographic features of the strata (marker layer) underground, facilitating comparison with the burial depth.

[0056] (6) Drilling trajectory deviation correction

[0057] Based on the vertical depth plane projection positioning of the marker layers encountered in the actual drilled wellbore and the wellbore trajectory orientation, determine whether there is any deviation between the two and the approximate distance of the deviation, and provide timely correction suggestions.

[0058] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A wellbore trajectory identification method based on marker layer vertical depth, characterized in that, Includes the following steps: Step 1. Obtain seismic data, well logging data, and stratigraphic data for the study area; Step 2. Refine and interpret seismic data and adjacent well data, and pre-select lithological marker layers in key well sections where well trajectory identification is required; the pre-selection of lithological marker layers specifically involves: based on the lithological and logging data of actual drilled wells and standard profiles of adjacent wells in the block, combined with regional lithological marker layers, pre-determining the depth, lithology, and logging curve characteristics of marker layers encountered during actual drilling operations on the stratigraphic profile; Step 3. Perform lithology inversion on the drilled wells to understand the seismic and logging curve characteristics corresponding to various lithologies, and then perform lithology inversion prediction on the actual drilled wells; Step 4. Perform fine processing on the seismic data volume around the actual drilling well, extract the two-dimensional plane of the lithological marker layer, and combine it with the top and bottom surface structural maps of the strata and sub-strata in the work area to restore the actual underground burial depth and geomorphological characteristics of each lithological marker layer. Step 5. Using a combination of drilling spontaneous potential, natural gamma, logging during drilling, elemental logging, hand specimens of cuttings, and scanning electron microscopy, as well as X-ray detection analysis to identify the mineral composition, elemental composition, and pore structure of the cuttings, determine whether a marker layer has been encountered and calculate the actual vertical depth of the marker layer encountered. Step 6. Calculate the vertical depth of the marker layer encountered during actual drilling and the vertical depth of the same marker layer encountered in the original wellbore. Project both vertical depth data onto the marker layer plane for comparison. Combine this with the azimuth angle between the well trajectory and the original wellbore to obtain the approximate positional deviation between the actual and original wellbore, and provide relevant correction suggestions. This includes: based on the azimuth angle between the well trajectory and the original wellbore, and the calculated vertical depth of the actual marker layer encountered, project it and the vertical depth of the marker layer encountered predicted by formation inversion onto the marker layer burial depth structural plan obtained by comprehensively processing seismic stratigraphic data. Comprehensively compare the burial depth, strike, dip angle, and thickness of the marker layer to identify the approximate position of the actual and predetermined wellbore trajectories on the same marker layer plane and determine whether there is a deviation.

2. The wellbore trajectory identification method based on marker layer vertical depth according to claim 1, characterized in that, In step 1, the seismic data includes a volume of three-dimensional seismic data of the actual drilling area and two-dimensional seismic profiles or plan views.

3. The wellbore trajectory identification method based on marker layer vertical depth according to claim 1, characterized in that, In step 1, the stratigraphic data includes the thickness plan of each stratum in the actual drilled well and surrounding area, the top and bottom structural map, the sub-layer plan, the standard lithological profile of the strata, the lithological marker layer data, and the strike and dip data of the strata.

4. The wellbore trajectory identification method based on marker layer vertical depth according to claim 1, characterized in that, In step 1, the logging data includes logging data from the actual drilled well and surrounding adjacent wells.

5. A wellbore trajectory recognition device based on marker layer vertical depth, characterized in that, include: The data acquisition module is used to acquire seismic data, well logging data, and stratigraphic data of the study area. The preprocessing module is used for fine processing and interpretation of seismic data and adjacent well data, and pre-selects lithological marker layers in key well sections where well trajectory identification is required. The pre-selection of lithological marker layers specifically involves: based on the lithological and logging data of the actual drilled well and the standard profile of the adjacent well in the block, combined with the regional lithological marker layers, the depth, lithology and logging curve characteristics of the marker layers encountered during actual drilling operations are pre-determined on the stratigraphic profile. The inversion prediction module is used to perform lithology inversion on drilled wells, understand the seismic and logging curve characteristics corresponding to various lithologies, and then perform lithology inversion prediction on actual drilled wells. The two-dimensional plane extraction module is used to perform fine processing on the seismic data volume around the actual drilling well and extract the two-dimensional plane of the lithological marker layer. Combined with the top and bottom surface structural maps of the strata and sub-strata in the work area, the actual underground burial depth and geomorphological characteristics of each lithological marker layer are restored. The marker layer vertical depth retrieval module is used to comprehensively analyze drilling spontaneous potential, natural gamma, logging during drilling, elemental logging, hand specimens of cuttings, and SEM observation and X-ray detection to identify the mineral composition, elemental composition, and pore structure of the cuttings, determine whether a marker layer has been encountered, and calculate the actual vertical depth of the marker layer encountered. The drilling trajectory deviation correction module is used to calculate the vertical depth of the actual drilled marker layer and the vertical depth of the same marker layer encountered in the original wellbore. The two vertical depth data are projected onto the marker layer plane for comparison. Combined with the azimuth angle between the well trajectory and the original wellbore, the approximate positional deviation between the actual drilled wellbore and the original wellbore is obtained, and relevant correction suggestions are provided. This includes: based on the azimuth angle between the well trajectory and the original wellbore, and the calculated actual drilled marker layer vertical depth, projecting it and the drilled marker layer vertical depth predicted by formation inversion onto a marker layer burial depth structural plan obtained by comprehensively processing seismic stratigraphic data. A comprehensive comparison is made of the marker layer burial depth, strike, dip angle, and layer thickness to identify the approximate position of the actual drilled wellbore trajectory and the predetermined wellbore trajectory on the same marker layer plane, and to determine whether a deviation exists.

6. A wellbore trajectory recognition system based on marker layer vertical depth, characterized in that, Includes one or more processors; A memory for storing one or more programs; the processor is configured to execute program instructions stored in the memory, which, when executed, perform the wellbore trajectory identification method based on the vertical depth of the marker layer as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program, when executed by one or more processors, implements the wellbore trajectory identification method based on the vertical depth of the marker layer as described in any one of claims 1 to 4.

Images