Micro logging systems, methods, apparatuses, and media

Abstract

The present application belongs to the field of petroleum geophysical exploration, and discloses a micro logging system, method, device and medium. The present application adopts a double cable structure, avoids the problem that the cable is too thick due to too many cable levels when one cable is used, and makes the cable more difficult to be lowered into the well and recovered. The present application adopts a ground excitation and well receiving mode, so that the cable can be reused, the number of detonators is reduced, the cost is lowered, and the safety is improved. The present application sets different trace intervals, the trace interval is 1m at a well depth of 0-20m, the trace interval is 2m at a well depth of 20-40m, and the trace interval is 4m below a well depth of 40m, so that the requirements of shallow layer measuring point density and cable thickness can be met, and the surface measurement precision is improved. The present application realizes a new method for investigating near-surface structure which is faster, more economical, safer and higher in precision, reduces the cost of micro logging, improves the measurement precision, and obtains high-quality micro logging data. The present application is suitable for the petroleum exploration industry.

Description

Technical Field

[0001] This invention belongs to the field of petroleum geophysical exploration, specifically a micro-logging system, method, device, and medium. Background Technology

[0002] Near-surface structure surveys are a crucial part of seismic exploration data acquisition and processing. Their main purpose is to obtain near-surface geological information to more accurately process seismic data and improve exploration results. Survey methods include small refraction and micrologging. Small refraction methods have stringent requirements regarding the working area's environment and geology, and are suitable for areas with flat surfaces and small subsurface interface dip angles. However, their surface survey results are not ideal in loess mountainous regions.

[0003] Micrologging is a mature and effective method for investigating near-surface structure and determining velocity values. Using micrologging data, the lateral and longitudinal variations of surface velocity and thickness within a seismic zone can be determined, allowing for the establishment of a relatively accurate surface velocity model and providing static correction values ​​for indoor seismic data processing. Micrologging is also used to investigate near-surface Q-values ​​and study near-surface attenuation compensation mechanisms, providing a basis for high-resolution processing. Compared to small-refraction methods, micrologging technology has lower requirements for the geological environment and site conditions, offers higher measurement accuracy, and is widely used in surface investigations during mountain seismic exploration.

[0004] The E Basin is characterized by its crisscrossing gullies and complex surface structure. This complex near-surface structure not only affects excitation and reception, making it difficult to obtain high signal-to-noise ratio raw data in the field, but also severely impacts seismic data imaging and amplitude fidelity processing, posing significant challenges to seismic exploration. Commonly used micrologging methods employ in-well excitation and surface reception. This method uses a large number of detonators for excitation at the surface, resulting in high costs and low efficiency. Furthermore, with increasingly stringent local environmental and safety regulations, the large-scale use of detonators is currently unavailable to meet the demands of micrologging. Additionally, the in-well excitation and surface reception method cannot meet the higher precision requirements for investigating the complex surface structure of loess hills.

[0005] In summary, the commonly used micrologging method, which involves in-well excitation and surface reception, cannot achieve faster, more economical, safer, and more accurate seismic exploration in areas with complex near-surface structures. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention aims to provide a micro-logging system, method, apparatus, and medium to achieve a faster, more economical, safer, and more accurate new method for investigating near-surface structures, reducing the cost of micro-logging while acquiring high-quality micro-logging data.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a micro-logging system, including a two-section multi-stage dedicated cable. The two-section multi-stage dedicated cable includes a multi-stage receiving cable one and a multi-stage receiving cable two. The multi-stage receiving cable one is a 31-level cable and the multi-stage receiving cable two is a 48-level cable. The end of the multi-stage receiving cable one near the wellhead and the end of the multi-stage receiving cable two near the wellhead are respectively connected to the ground control equipment. It also includes multiple geophones that are spaced throughout the well section, and the multiple geophones are connected to the interface of the first multi-level receiving cable and the interface of the second multi-level receiving cable, respectively.

[0008] As a limitation of the present invention: both the detector and the multi-stage receiving cable one, and the detector and the multi-stage receiving cable two, are isolated by soft partitions.

[0009] As a further limitation of the present invention: the 31-level cable is located in the well near the wellhead, the 48-level cable is located below the 31-level cable, and the top ends of both the 31-level cable and the 48-level cable are connected to the ground control equipment.

[0010] This invention also provides a micro-logging method, which employs a micro-logging system and includes the following steps: S1. Lower the two-section multi-stage special cable equipped with the detector into the well, and connect the end of the multi-stage receiving cable one near the wellhead and the end of the multi-stage receiving cable two near the wellhead to the ground control equipment respectively. S2. Using the method of ground excitation and well reception, ground excitation is performed 5m away from the receiving well, and the entire well section is received using a two-section multi-stage dedicated cable and a geophone, and the received data is transmitted to the ground control equipment; S3. After the measurement of this well is completed, the two-section multi-stage dedicated cable is pulled out of the well for necessary maintenance and upkeep, and left to be lowered into other wells for measurement.

[0011] As a limitation of the present invention: the total length of the 31-level cable is 65m, the effective length is 40m, and it is used to collect information from the surface layer of 0-40m; the total length of the 48-level cable is 305m, the effective length is 200m, and it is used to collect information from well depths below 40m.

[0012] As a further limitation of the present invention: the spacing between channels is 1m for well depths of 0-20m, 2m for well depths of 20-40m, and 4m for well depths below 40m.

[0013] This invention also provides a micro-logging seismic data processing device for implementing micro-logging methods, including: The data acquisition module is used to acquire single shot gather or shot gather data from micro-logging. The initial arrival picking module is used to pick the initial arrival of micro-logging single shot gather or shot gather data; The data interpretation module interprets the picked arrival times to obtain the time-distance curve.

[0014] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, is used to implement a micro-logging method.

[0015] By adopting the above technical solution, the beneficial effects achieved by the present invention compared with the prior art are as follows: This invention employs a ground-based excitation and in-well reception method, requiring only one excitation and approximately 30-50 detonators. In contrast, traditional micro-logging uses an in-well excitation and ground-based reception method. Taking a 100-meter micro-logging well as an example, 40 excitation points need to be deployed underground, with 30 detonators at each point, totaling 1200 detonators. Compared to this, the invention effectively reduces the number of detonators used, making it safer and significantly lowering construction costs, thus being more economical. Furthermore, the ground-based excitation and in-well reception method allows for the reuse of dual cables, improving resource utilization and reducing measurement time and costs, further enhancing economic efficiency. This invention employs a dual-cable structure with a two-section, multi-stage dedicated cable. This avoids the problem of excessive cable thickness due to too many stages when using a single cable, which makes cable deployment and retrieval difficult. This allows for faster deployment and retrieval operations. Furthermore, the dual-cable structure provides better anti-interference and wear resistance, reducing the impact of cable waves and improving measurement accuracy. The invention also sets different track spacings throughout the well section: 1m for depths of 0-20m, 2m for depths of 20-40m, and 4m for depths below 40m. This approach balances the density requirements of shallow measurement points with the requirements for cable thickness and weight, improving both surface measurement accuracy and economy.

[0016] In summary, this invention provides a new method for investigating near-surface structures that is faster, more economical, safer, and more accurate, reducing the cost of micrologging, improving measurement accuracy, and obtaining high-quality micrologging data; it is applicable to the petroleum exploration industry. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 This is a schematic diagram of the structure of the 31-level cable and detector in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the 48-level cable and detector in an embodiment of the present invention; Figure 3 This is a schematic diagram of the construction status of Class 31 and Class 48 cables in an embodiment of the present invention; Figure 4 This is a schematic diagram of the common shot point gather obtained by conventional micrologging methods. Figure 5 This is a schematic diagram of the common shot point gather obtained by the micro-logging method of the present invention; Figure 6 This is a schematic diagram of the time-distance curve obtained by conventional micro-logging methods; Figure 7 This is a schematic diagram of the time-distance curve obtained by the micro-logging method of the present invention.

[0019] In the diagram: 1-31 grade cable, 2-48 grade cable, 3-detector. Detailed Implementation

[0020] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the micro-logging system, method, apparatus, and medium described herein are preferred embodiments and are only used for illustration and explanation of the present invention, and do not constitute a limitation thereof.

[0021] A first exemplary embodiment of the present invention provides a micro-logging system, which includes a two-section multi-stage dedicated cable, comprising a multi-stage receiving cable one and a multi-stage receiving cable two. In this embodiment, the multi-stage receiving cable one is a 31-stage cable 1, the structure of which is described below. Figure 1 The second multi-stage receiving cable is a 48-level cable, the structure of which is described in [reference needed]. Figure 2 Here, "Cable 31 (1)" means the cable can connect 30 geophones (3), and "Cable 48 (2)" means the cable can connect 48 geophones (3). This dual-cable structure has better anti-interference and wear resistance, improving measurement accuracy and stability. In practical applications, the cable class can be selected based on the well depth and the number of geophones (3) to be connected.

[0022] It also includes multiple geophones 3. In this embodiment, there are a total of 78 geophones 3, which are deployed at intervals throughout the well section. See [link to documentation]. Figure 3 Multiple geophones 3 are connected to the interfaces of multi-stage receiving cable one and multi-stage receiving cable two, respectively. That is, 30 geophones 3 are connected to 30 interfaces of multi-stage receiving cable one, and 48 geophones 3 are connected to 48 interfaces of multi-stage receiving cable two. The connection between the geophones 3 and the cable interfaces is existing technology and will not be described in detail in this embodiment. In this embodiment, the geophones 3 are externally connected, allowing them to be disassembled and replaced at any time to ensure the effectiveness of the logging results.

[0023] Furthermore, such as Figure 1 , 2As shown, detector 3 is isolated from multi-stage receiving cable one and from multi-stage receiving cable two by flexible partitions, which are made of existing soft plastic foam. If flexible partitions are not used between detector 3 and multi-stage receiving cable, cable waves will appear, which will affect the initial arrival pickup and measurement accuracy. In this embodiment, the use of flexible partitions can avoid the occurrence of cable waves.

[0024] In this micro-logging system, the ends of multi-stage receiving cable 1 and multi-stage receiving cable 2 near the wellhead are each connected to the surface control equipment. Specifically, the 31-level cable 1 is positioned in the well near the wellhead, and the 48-level cable 2 is located below the 31-level cable 1. The top ends of both the 31-level cable 1 and the 48-level cable 2 are connected to the surface control equipment. This dual-cable simultaneous reception method, combining multi-stage receiving cable 1 and multi-stage receiving cable 2, serves two purposes: first, it avoids the problem of excessive cable thickness due to too many cable stages when using a single cable, which would make cable lowering and retrieval difficult, thus reducing construction difficulty and safety risks; second, it minimizes the impact of cable waves.

[0025] A second exemplary embodiment of the present invention provides a micro logging method using the above-described micro logging system, the method comprising the following steps: S1. Lower a two-section multi-stage dedicated cable equipped with detector 3 into the well. Connect the ends of multi-stage receiving cable one and multi-stage receiving cable two near the wellhead to the surface control equipment. This receiving method allows the two-section multi-stage dedicated cable to cover the entire well section, improving measurement accuracy and efficiency while reducing measurement time and cost. Furthermore, the two-section cable design enables measurements at different logging depths, further reducing safety risks while minimizing measurement time and workload.

[0026] The specific lengths of multi-level receiving cable one and multi-level receiving cable two in this embodiment are as follows: like Figure 1 As shown, the total length of the Class 31 cable 1 is L1=65m. Since the Class 31 cable 1 needs to be connected to the instrument, its head length is set to L3=20m; its tail length is L4=5m, which can be attached with a weight to assist in going down into the well. The effective length is L2=40m, which is used to collect information from the surface layer 0-40m.

[0027] like Figure 2 As shown, the total length of the 48-level cable 2 is L7=305m. The 48-level cable 2 also needs to be connected to the instrument, so its head length is set to L9==100m; the tail length is L10=5m, which can be attached with a weight to assist in going down into the well, and the effective length is L8=200m, which is used to collect information below a well depth of 40m.

[0028] Since 0-40m is considered shallow depth, the effective length of the 31-level cable 1 is set to 40m. Because the depth of micro-logging is not fixed, this embodiment sets the multi-stage receiving cable 2 as a long cable to better adapt to different logging depths, expanding the measurement range and improving measurement flexibility and adaptability. In this embodiment, the lengths set for the 31-level cable 1 and the 48-level cable 2 ensure that the logging depth meets all measurement requirements.

[0029] The channel spacing refers to the distance between each geophone 3 embedded in the measuring line. Due to the rapid changes in velocity at shallow depths, according to the requirements of micro-logging construction, the number of shallow measuring points needs to be appropriately increased. This invention employs geophone spacing with different depths. Specifically, on the 31-grade cable 1, the channel spacing is L5=1m at depths of 0-20m and L6=2m at depths of 20-40m. On the 48-grade cable 2, i.e., at depths below 40m, the channel spacing is L11=4m. Geophones 3 are arranged accordingly for information acquisition. This design can balance the requirements of shallow measuring point density with the requirements of cable thickness and weight, improving the flexibility and adaptability of measurement, and enhancing the accuracy and economy of surface measurement.

[0030] S2. A ground-based excitation and well-based receiving method is adopted, such as... Figure 3 As shown, ground excitation is performed at a distance of 5m from the receiving well L12. The entire well section is received using a two-section multi-stage dedicated cable and detector 3, and the received data is transmitted to the ground control equipment.

[0031] Here, detonators can be used for ground-based activation, or other more environmentally friendly activation methods such as controlled seismic sources or heavy hammers can be selected. However, it should be noted that even with detonator activation, this invention uses a ground-based activation and in-well reception method, requiring only one activation and approximately 30-50 detonators for reception throughout the entire well section. In contrast, traditional micrologging uses an in-well activation and ground-based reception method; a 100-meter micrologging well requires 40 activation points downhole, with 30 detonators at each point, totaling 1200 detonators. Therefore, this invention effectively reduces the number of detonators used, reduces safety risks, and significantly lowers construction costs by approximately 57.3%.

[0032] In addition, the micro-logging method of the present invention adopts a full-well section receiving method, which can simultaneously receive data from multiple measuring points, greatly improving construction efficiency.

[0033] S3. After the measurement of this well is completed, the two-section multi-stage dedicated cable is pulled out of the well for necessary maintenance and upkeep, and left to be lowered into other wells for measurement.

[0034] Traditional methods involve attaching a detonator to a cable and lowering it into the well for in-well activation. When the detonator explodes, the cable is damaged and cannot be reused. In this embodiment, the detonator is activated on the ground, and the cable receives the detonation in the well. Therefore, the two-section, multi-stage dedicated cable can be reused, improving resource utilization, reducing measurement time and costs, and increasing construction efficiency.

[0035] Figure 5 This is the common shot gather obtained by the micro-logging method in this embodiment. Figure 4 The common shot gathers obtained by the conventional micrologging method show that the micrologging data obtained by this method have a more crisp first arrival jump, indicating that there is less interference when picking up the first arrival time, and correspondingly, the accuracy of the received signal is higher.

[0036] from Figure 6 It can be seen that the low-velocity thickness obtained by conventional micro-logging methods is h0 + h1 + h2 + h3 = 137 m. Figure 7 It can be seen that the low-velocity layer thickness obtained by the micro-logging method in this embodiment is h0+h1+h2+h3=143.4m, which is close to the low-velocity layer thickness obtained by the two methods. The high-velocity layer velocity V4 obtained by the conventional micro-logging method is 3159m / s, while the high-velocity layer velocity V4 obtained by the micro-logging method in this embodiment is 3178m / s. The difference between the two is not significant. Therefore, the data collected by this invention has a high degree of consistency with the actual situation. While ensuring the quality of micro-logging data, it can also reduce costs, improve safety and measurement accuracy.

[0037] A third exemplary embodiment of the present invention provides a micro-logging seismic data processing apparatus for implementing the above-described micro-logging method, comprising: The data acquisition module is used to acquire single shot gather or shot gather data from micro-logging. The initial arrival picking module is used to pick the initial arrival of micro-logging single shot gather or shot gather data; The data interpretation module interprets the picked arrival times to obtain the time-distance curve.

[0038] A fourth exemplary embodiment of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, is used to implement the above-described micro-logging method.

[0039] The computer-readable storage medium stores non-transitory computer-readable instructions thereon. When the non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the methods described in the foregoing embodiments are performed.

[0040] Computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or portable hard drive), media with built-in rewritable non-volatile memory (e.g., memory card), and media with built-in ROM (e.g., ROM cartridge).

[0041] It should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A micro-logging system, characterized in that, It includes a two-section multi-level dedicated cable, which consists of a multi-level receiving cable one and a multi-level receiving cable two. The multi-level receiving cable one is a 31-level cable and the multi-level receiving cable two is a 48-level cable. The end of the multi-level receiving cable one near the wellhead and the end of the multi-level receiving cable two near the wellhead are respectively connected to the ground control equipment. It also includes multiple geophones that are spaced throughout the well section, and the multiple geophones are connected to the interface of the first multi-level receiving cable and the interface of the second multi-level receiving cable, respectively.

2. The micro-logging system according to claim 1, characterized in that, Both the detector and the multi-stage receiving cable 1, and the detector and the multi-stage receiving cable 2, are isolated by soft partitions.

3. The micro-logging system according to claim 2, characterized in that, The 31-level cable is installed in the well near the wellhead, and the 48-level cable is located below the 31-level cable. The top ends of both the 31-level cable and the 48-level cable are connected to the ground control equipment.

4. A micro-logging method, employing the micro-logging system according to any one of claims 1-3, characterized in that, The method includes the following steps: S1. Lower the two-section multi-stage special cable equipped with the detector into the well, and connect the end of the multi-stage receiving cable one near the wellhead and the end of the multi-stage receiving cable two near the wellhead to the ground control equipment respectively. S2. Using the method of ground excitation and well reception, ground excitation is performed 5m away from the receiving well, and the entire well section is received using a two-section multi-stage dedicated cable and a geophone, and the received data is transmitted to the ground control equipment; S3. After the measurement of this well is completed, the two-section multi-stage dedicated cable is pulled out of the well for necessary maintenance and upkeep, and left to be lowered into other wells for measurement.

5. The micro-logging method according to claim 4, characterized in that, The Class 31 cable has a total length of 65m and an effective length of 40m, and is used to collect information from the surface layer of 0-40m; the Class 48 cable has a total length of 305m and an effective length of 200m, and is used to collect information from depths below 40m.

6. The micro-logging method according to claim 5, characterized in that, The spacing between runners is 1m for well depths of 0-20m, 2m for well depths of 20-40m, and 4m for well depths below 40m.

7. A micro-logging seismic data processing device for implementing the micro-logging method according to any one of claims 4-6, characterized in that, include, The data acquisition module is used to acquire single shot gather or shot gather data from micro-logging. The initial arrival picking module is used to pick the initial arrival of micro-logging single shot gather or shot gather data; The data interpretation module interprets the picked arrival times to obtain the time-distance curve.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, is used to implement the micro-logging method according to any one of claims 4-6.

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