A salt cavern energy storage injection-production well salt cavity top control method and system
By combining seismic data, sonar technology, and X-ray fluorescence technology, the problem of large error in the control of the top of the salt cavity in salt cavern energy storage injection and production wells was solved, and the precise identification and control of the top of the salt cavity was achieved with an error of ±2m, which meets the design requirements of compressed air energy storage wells.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CNPC BOHAI DRILLING ENG
- Filing Date
- 2024-12-17
- Publication Date
- 2026-06-19
AI Technical Summary
Existing methods for controlling the top of the salt cavity in salt cavern energy storage injection and production wells have large errors, making accurate identification difficult and failing to meet the design requirements of compressed air energy storage wells.
The depth of the top of the salt cavity was obtained by combining seismic data with sonar technology, and the lithology was identified by X-ray fluorescence technology. By combining the core data of the drilled wells and comparing the lithological variation patterns with the cavity top depth, the depth of the top of the salt cavity was accurately identified.
Precise control of the top of the salt chamber was achieved with an error of ±2m, meeting the design requirements of compressed air energy storage wells and improving the accuracy of the control of the top of the salt chamber.
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Figure CN122236431A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of new energy, and more specifically, relates to a method and system for controlling the top of the salt cavity in a salt cavern energy storage injection-production well. Background Technology
[0002] Compressed air energy storage (CAS) is currently one of the most popular and emerging low-carbon industries. CAS boasts advantages such as large-scale operation, long operating time, low cost, high efficiency, safety, and environmental friendliness, making it one of the most promising large-scale energy storage technologies. For CAS injection-production wells, the well depth structure design requires controlling the drilling depth to 20m above the salt cavity top after the second drilling phase. According to the design requirements, a control method for the top of the salt cavity needs to be established. Currently, there are no relevant documents or patents in the industry regarding methods for controlling the layer at the top of the salt cavity in CAS wells. There are currently no comparable cases regarding the layer control accuracy of CAS wells. Compared to the layer control accuracy of ±5-10m in conventional oil and gas drilling wells, this method offers higher layer control accuracy.
[0003] Typically, existing stratigraphic positioning methods are based on traditional stratigraphic profile comparison methods. These methods utilize data from adjacent wells (already drilled wells) to obtain stratigraphic lithology and sequence information. During the drilling of a new well, the lithological horizons of the new well are compared with those of adjacent wells (already drilled wells) to determine the stratigraphic location of the new well. However, this method is influenced by many factors, such as geological structure, stratigraphic thickness, and subsequent tectonic movements, resulting in significant errors.
[0004] In addition, existing methods include identifying lithology by sight, determining its name, and then using marker beds and lithological variations to determine potential drilling locations. However, visually identifying lithology during the lithology identification process can lead to errors in perception, misleading stratigraphic correlation and judgment. This method has limitations, large errors, and cannot accurately determine the location of strata.
[0005] Therefore, there is an urgent need to design a method for controlling the top of the salt cavity in salt cavern energy storage injection and production wells that can solve the above problems. Summary of the Invention
[0006] The purpose of this invention is to establish a control method capable of accurately identifying the top of the salt cavity in a compressed air energy storage injection-production well. Specifically, it provides a method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well.
[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: According to one aspect of the present invention, a method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well is provided, comprising the following steps: Obtain the depth of the top of the salt cavity; Based on the core data from drilled wells, determine the lithological variation patterns; Lithological identification of drilling wells is performed using X-ray fluorescence technology. By comparing the named lithology with the determined lithological variation patterns and combining this with the obtained cavity top depth, a depth card is constructed at the top of the salt cavity.
[0008] In one embodiment of the present invention, the depth of the top of the salt cavity is obtained by combining seismic data with sonar technology.
[0009] In one embodiment of the present invention, the depth of the top of the salt cavity is obtained by combining seismic data with sonar technology, including: By combining seismic data with audio geodetic inversion results, a geological model was established, and the seismic response characteristics of the top and bottom of the salt cavity were inferred. The spatial distribution of the salt layer and the salt cavity was identified, and the depth of the top of the salt cavity was obtained by interfacing with sonar technology.
[0010] In one embodiment of the present invention, the seismic data includes a time-domain seismic profile, which can be converted to a depth-domain seismic profile.
[0011] In one embodiment of the present invention, determining the lithological variation pattern based on core data from drilled wells includes: Based on the core data from drilled wells, the stratigraphic sequence and lithological variation patterns are established.
[0012] In one embodiment of the present invention, X-ray fluorescence technique is used to identify the lithology of a well being drilled, including: X-ray fluorescence technique was used to analyze the rock cuttings from the drilling well to obtain elemental data, and the lithology of the rock cuttings was determined based on the magnitude and proportion of the elemental data.
[0013] In one embodiment of the invention, the named lithologies include halite, mirabilite, gypsum, sandstone, and mudstone.
[0014] In one embodiment of the present invention, when the mass percentage of the sum of Na and Cl elements is 20.5-60.3% and the mass percentage of the sum of Ca, S, and P elements is 3.8-19.2%, the lithology is named halite. When the combined mass percentage of Na and Cl is 7.6-14.5% and the combined mass percentage of Ca, S, and P is 9.9-17.0%, the lithology is named mirabilite. When the mass percentage of Na and Cl is 2.0-4.5% and the mass percentage of Ca, S and P is 26.9-39.7%, the lithology is named gypsum. When the combined mass percentage of Na and Cl is 1.4-10.3% and the combined mass percentage of Ca, S, and P is 3.5-4.8%, the lithology is designated as sandstone. When the combined mass percentage of Na and Cl is 0-1.3% and the combined mass percentage of Ca, S, and P is 12.2-18.0%, the lithology is designated as mudstone.
[0015] In one embodiment of the present invention, the named lithology is compared with the determined lithological variation pattern, and combined with the obtained cavity top depth, a salt cavity top depth stratification is performed, including: Based on the named lithology, a stratigraphic lithology profile is obtained, and the profile of the drilling well is compared with the profile of the cored well. At the same time, the depth of the top of the salt cavity is combined to determine the top depth of the salt cavity.
[0016] In one embodiment of the present invention, the depth of the top layer of the salt cavity is 20±2m.
[0017] According to another aspect of the present invention, a top control system for the salt cavity of a salt cavern energy storage injection-production well is provided, comprising: A first module is configured to obtain the depth of the top of the salt cavity; The second module is configured to determine the lithological variation patterns based on core data from drilled wells; The third module is configured to use X-ray fluorescence technology to identify the lithology of the well being drilled. The fourth module is configured to compare the named lithology with the determined lithological variation patterns and, in conjunction with the obtained cavity top depth, perform a salt cavity top depth stratification.
[0018] By adopting the above technical solution, the present invention has the following advantages compared with the prior art: This invention can accurately identify the top of the salt cavity in compressed air energy storage injection-production wells, with a salt cavity top layer jamming error of ±2m. This invention also develops a method for controlling the top of the salt cavity in salt cavern energy storage injection-production wells, a method that is at the forefront in China. Attached Figure Description
[0019] Figure 1 A schematic flowchart of a method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well provided by the present invention is shown. Figure 2 An embodiment of the present invention is shown. Figure 1 The method is used to create a three-dimensional visualization of the target area cavity of the salt cavity top layer; Figure 3 It shows Figure 2 A diagram showing the top surface of the target area cavity; Figure 4An embodiment of the present invention is shown. Figure 1 A schematic diagram of X-ray fluorescence lithology identification in the method; Figure 5 An embodiment of the present invention is shown. Figure 1 The various lithological profiles were obtained using X-ray fluorescence techniques. Detailed Implementation
[0020] It should be understood that the embodiments of the invention shown in the exemplary embodiments are merely illustrative. Although only a few embodiments have been described in detail in this invention, those skilled in the art will readily recognize that various modifications are possible without substantially departing from the teachings of the invention. Accordingly, all such modifications should be included within the scope of the invention. Other substitutions, modifications, variations, and deletions can be made to the design, operating conditions, and parameters of the following exemplary embodiments without departing from the spirit of the invention.
[0021] like Figure 1 As shown, the present invention provides a method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well, comprising the following steps: S101: Obtain the depth of the top of the salt cavity; S102: Determine the lithological variation patterns based on the core data from drilled wells; S103: Lithological identification of drilling wells using X-ray fluorescence technology; S104: Compare the named lithology with the determined lithological variation patterns, and combine this with the obtained cavity top depth to perform a salt cavity top depth stratification.
[0022] Through the above-described technical solution of this invention, the top of the salt cavity in compressed air energy storage injection-production wells can be accurately identified, with a salt cavity top layer jamming error of ±2m. This invention has developed a method for controlling the top of the salt cavity in salt cavern energy storage injection-production wells, which is at the leading level in China.
[0023] In the above-mentioned method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well, in step S101, the depth of the top of the salt cavity is obtained by combining seismic data with sonar technology.
[0024] In the aforementioned method for controlling the top of the salt cavity in salt cavern energy storage injection-production wells, the depth of the salt cavity top is obtained by combining seismic data with sonar technology, including: By combining seismic data with audio geodetic inversion results, a geological model was established, and the seismic response characteristics of the top and bottom of the salt cavity were inferred. The spatial distribution of the salt layer and the salt cavity was identified, and the depth of the top of the salt cavity was obtained by interfacing with sonar technology.
[0025] In the above-mentioned method for controlling the top of the salt cavity in salt cavern energy injection and production wells, the seismic data includes time-domain seismic profiles, which can be converted to depth-domain seismic profiles.
[0026] In the above-mentioned method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well, step S102 includes: Based on the core data from drilled wells, the stratigraphic sequence and lithological variation patterns are established.
[0027] In the above-mentioned method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well, step S103 includes: X-ray fluorescence technique was used to analyze the rock cuttings from the drilling well to obtain elemental data, and the lithology of the rock cuttings was determined based on the magnitude and proportion of the elemental data.
[0028] In the above-mentioned method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well, in step S103, the named lithologies include halite, mirabilite, gypsum, sandstone, and mudstone.
[0029] In the above-mentioned method for controlling the top of the salt cavity in salt cavern energy injection and production wells, as shown in Table 1 below, the following standards are used for lithology analysis: When the combined mass percentage of Na and Cl is 20.5-60.3% and the combined mass percentage of Ca, S, and P is 3.8-19.2%, the lithology is named halite. When the combined mass percentage of Na and Cl is 7.6-14.5% and the combined mass percentage of Ca, S, and P is 9.9-17.0%, the lithology is named mirabilite. When the mass percentage of Na and Cl is 2.0-4.5% and the mass percentage of Ca, S and P is 26.9-39.7%, the lithology is named gypsum. When the combined mass percentage of Na and Cl is 1.4-10.3% and the combined mass percentage of Ca, S, and P is 3.5-4.8%, the lithology is designated as sandstone. When the combined mass percentage of Na and Cl is 0-1.3% and the combined mass percentage of Ca, S, and P is 12.2-18.0%, the lithology is designated as mudstone.
[0030] Table 1: Lithological Nomenclature Standards Based on X-ray Fluorescence Technique
[0031] In the above-mentioned method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well, step S104 includes: Based on the named lithology, a stratigraphic lithology profile is obtained, and the profile of the drilling well is compared with the profile of the cored well. At the same time, the depth of the top of the salt cavity is combined to determine the top depth of the salt cavity.
[0032] In the above-mentioned method for controlling the top of the salt cavity in salt cavern energy storage injection and production wells, the depth of the top of the salt cavity is 20±2m.
[0033] Furthermore, the present invention also provides a corresponding salt cavern energy storage injection-production well salt cavity top control system, comprising: A first module is configured to obtain the depth of the top of the salt cavity; The second module is configured to determine the lithological variation patterns based on core data from drilled wells; The third module is configured to use X-ray fluorescence technology to identify the lithology of the well being drilled. The fourth module is configured to compare the named lithology with the determined lithological variation patterns and, in conjunction with the obtained cavity top depth, perform a salt cavity top depth stratification.
[0034] The technical solutions of the present invention will be described in detail below through specific embodiments.
[0035] Analysis of currently available data indicates significant variations in the depth of the cavity roof. Due to varying degrees of erosion and collapse, the roof depth of adjacent areas within the salt cavern cavity may differ considerably. Accurate prediction of the salt cavern roof depth is challenging due to limitations in the precision and accuracy of 3D seismic and sonar data, making the determination of the intermediate completion depth particularly difficult. To ensure cementing quality, the design requires an intermediate completion depth of 20m above the salt cavern top. Therefore, a control method capable of precisely identifying the top of the salt cavern in compressed air storage injection-production wells needs to be established.
[0036] In this invention, seismic data is first utilized in conjunction with audio-visual geodetic inversion results to establish a geological model based on existing data. This model relies on the fact that different rock layers have different velocities and densities; the product of these two is the wave impedance. Differences in wave impedance generate reflection coefficients, which can be used to guide seismic identification of gas-bearing strata. This allows for the approximate estimation of the seismic response characteristics at the top and bottom of the salt cavity, and the identification of the spatial distribution of salt layers and the salt cavity. Simultaneously, this is integrated with sonar technology to obtain the cavity top height. Then, core data from drilled wells is used to establish stratigraphic sequence and lithological variation patterns. Finally, X-ray fluorescence spectrometry is used to analyze data from ongoing drilling wells. Lithological names are determined based on the data information, and the named lithologies are compared with the established lithological variation patterns to determine the depth of the salt cavity top in this well.
[0037] More specifically, in the salt cavity top depth control method of the present invention, a combination of seismic, sonar and X-ray fluorescence technology is used to establish a comprehensive salt cavity top control method under the condition that the lithology of salt cavern injection and production wells is complex and variable and it is not easy to accurately determine the formation depth. This method can accurately control the top of the salt cavity up to 20m with an error of ±2m.
[0038] The steps of this method are as follows: First, seismic data was used to preliminarily obtain the structure of the salt cavern cavities. The seismic data was time-domain seismic profiles, which allowed for the description of the cavity morphology. The time-domain results were then converted to the depth domain for a more detailed description of the cavity morphology. The time-depth conversion yielded the following structural maps: Top boundary map of the salt cavern, red indicating relatively high structural values and blue indicating relatively low structural values; Bottom boundary map of the salt cavern, also after time-depth conversion, red indicating relatively high structural areas and blue indicating relatively low structural areas. Figure 2-3 As shown, areas of the same color represent areas at the same underground depth. Red represents the top of the salt cavity, and blue represents the bottom. The shape of the cavity can be roughly determined by the color changes.
[0039] Then, based on the coring data from the drilled wells, the profile of the cored wells is determined.
[0040] Next, X-ray fluorescence spectrometry is used to analyze the rock cuttings from the drilling well, obtaining elemental data. Based on the magnitude and proportion of the elemental data, the lithology of the rock cuttings is determined, thus obtaining a stratigraphic lithology profile. For example... Figure 4 As shown, during lithological identification, elemental data were obtained from rock cutting samples using X-ray fluorescence spectrometry. These data were then used... Figure 4 The lithology identification criteria are used to determine the lithology and form a lithological profile.
[0041] Finally, the obtained lithological profiles of the drilling wells are compared with the profiles obtained from cored core samples of the drilled wells, and the top of the salt cavity is comprehensively interpreted in conjunction with the predicted depth of the salt cavity from seismic data. For example... Figure 5 As shown, Figure 5 It is a lithological profile map established through elemental technology. By comparing this lithological profile map with the profile of the core taken from the drilled well (exploratory well), it is possible to infer the position reached in the drilling well, that is, to accurately pinpoint the position 20m before entering the cavity.
[0042] Through the above embodiments of the present invention, the present invention can accurately identify the top of the salt cavity in compressed air energy storage injection and production wells, with a 20m layer stuck at the top of the salt cavity, and an error of ±2m.
[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications or equivalent substitutions made to the present invention without departing from the spirit and scope thereof should be covered within the protection scope of the claims of the present invention.
Claims
1. A method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well, characterized in that, Includes the following steps: Obtain the depth of the top of the salt cavity; Based on the core data from drilled wells, determine the lithological variation patterns; Lithological identification of drilling wells is performed using X-ray fluorescence technology. By comparing the named lithology with the determined lithological variation patterns and combining this with the obtained cavity top depth, a depth card is constructed at the top of the salt cavity.
2. The method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well according to claim 1, characterized in that, The depth of the salt cavity top is obtained by combining seismic data with sonar technology.
3. The method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well according to claim 2, characterized in that, The depth of the salt cavity roof is determined by combining seismic data with sonar technology, including: By combining seismic data with audio geodetic inversion results, a geological model was established, and the seismic response characteristics of the top and bottom of the salt cavity were inferred. The spatial distribution of the salt layer and the salt cavity was identified, and the depth of the top of the salt cavity was obtained by interfacing with sonar technology.
4. The method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well according to claim 2, characterized in that, Seismic data includes time-domain seismic profiles that can be converted to depth-domain seismic profiles.
5. The method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well according to claim 1, characterized in that, Based on core data from drilled wells, determine the lithological variation patterns, including: Based on the core data from drilled wells, the stratigraphic sequence and lithological variation patterns are established.
6. The method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well according to claim 1, characterized in that, Lithological identification of drilling wells using X-ray fluorescence technique, including: X-ray fluorescence technique was used to analyze the rock cuttings from the drilling well to obtain elemental data, and the lithology of the rock cuttings was determined based on the magnitude and proportion of the elemental data.
7. The method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well according to claim 1, characterized in that, The named lithologies include halite, mirabilite, gypsum, sandstone, and mudstone.
8. The method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well according to claim 7, characterized in that, When the combined mass percentage of Na and Cl is 20.5-60.3% and the combined mass percentage of Ca, S, and P is 3.8-19.2%, the lithology is named halite. When the combined mass percentage of Na and Cl is 7.6-14.5% and the combined mass percentage of Ca, S, and P is 9.9-17.0%, the lithology is named mirabilite. When the mass percentage of Na and Cl is 2.0-4.5% and the mass percentage of Ca, S and P is 26.9-39.7%, the lithology is named gypsum. When the combined mass percentage of Na and Cl is 1.4-10.3% and the combined mass percentage of Ca, S, and P is 3.5-4.8%, the lithology is designated as sandstone. When the combined mass percentage of Na and Cl is 0-1.3% and the combined mass percentage of Ca, S, and P is 12.2-18.0%, the lithology is designated as mudstone.
9. The method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well according to claim 1, characterized in that, By comparing the named lithology with the established lithological variation patterns, and combining this with the obtained cavity top depth, a depth card is constructed at the top of the salt cavity, including: Based on the named lithology, a stratigraphic lithology profile is obtained, and the profile of the drilling well is compared with the profile of the cored well. At the same time, the depth of the top of the salt cavity is combined to determine the top depth of the salt cavity.
10. The method for controlling the top of the salt cavity in a salt cavern energy storage injection-production well according to claim 1, characterized in that, The depth of the salt cavity top layer is 20±2m.
11. A control system for the top of the salt cavity in a salt cavern energy storage injection-production well, characterized in that, include: The first module is configured to obtain the depth of the top of the salt cavity; The second module is configured to determine the lithological variation patterns based on the core data from the drilled wells; The third module is configured to use X-ray fluorescence technology to identify the lithology of the drilling well. The fourth module is configured to compare the named lithology with the determined lithological variation law, and combine it with the obtained cavity top depth to perform salt cavity top depth stratification.