Micro-logging excitation device

Abstract

The utility model discloses a micro-logging excitation device, and relates to the technical field of seismic exploration, in particular to the micro-logging excitation device, which comprises a geophone string and a seismograph, the geophone string is lowered into a micro-logging through a rope, the seismograph is arranged on the earth surface, and the geophone string comprises at least one first geophone; through the arrangement of the firecracker excitation part, the micro-logging excitation device has the effect of performing seismic source excitation on the earth surface nearby a micro-logging, a pit hole is dug in an earth surface hard soil layer, a firecracker is placed in the pit hole, an iron chisel is inserted into earth surface soil, a disc drives a sleeve to cover the firecracker, and the firecracker excitation part is used for exciting the firecracker. The firecracker is tightly fixed to hard earth surface soil through cooperation of the iron drill rod, the disc and the sleeve, the firecracker is ignited and used as an energy source, low-cost earth surface seismic source excitation is achieved, and compared with the prior art, the firecracker is easy to obtain and low in cost, and the micro-logging ground excitation construction progress is not affected. And the firecracker is wide in application range and can be used in various complex environments.

Description

Technical Field

[0001] The utility model relates to the technical field of seismic exploration, in particular to a micro-well logging excitation device. Background Art

[0002] In seismic exploration, the investigation of near-surface geological structures is crucial. It is related to whether a reliable basis can be provided for the selection of excitation factors for seismic data acquisition, whether accurate static correction can be extracted for data processing, and whether the absorption and attenuation of seismic waves by the formation can be obtained, that is, the formation quality factor Q value, which is used to compensate for high-frequency seismic signals and improve the resolution of ground seismic profiles. Micro-logging technology is considered to be the most effective technical method for obtaining the above parameters. The commonly used data acquisition method for micro-logging is to excite seismic waves on the ground, receive them with detectors at different depths in the well, obtain the first arrival time of the seismic waves, obtain the vertical time after the well source distance correction, fit the time-depth curve, obtain the vertical velocity and layer thickness in the formation, and use the first arrival wave spectrum and time at different depths to estimate the formation Q value.

[0003] For ground excitation, the source selection method is flexible, and both explosive sources and non-explosive sources can be used. Explosive sources have strong excitation energy, but the purchase, storage, transportation, and use of detonators and explosives are strictly controlled, the approval procedures are complicated, and the cycle is long. Non-explosive sources mainly include sparks, air guns, and heavy hammers. There are shortcomings in non-explosive sources: such as spark sources, which need to be equipped with generators and high-voltage charging equipment, which are costly and difficult to carry, and there are also random delay problems; air gun sources must be excited in water, and the device is difficult to carry; heavy hammer sources have poor consistency and weak energy. For micro-well logging construction with smaller required excitation energy, the prior art "A special excitation device for field micro-well logging construction in seismic exploration", patent number 202322299613.7, uses combustible gas as excitation energy, avoiding the control restrictions of civil explosives, and because it is excited in water, the excitation consistency is better. However, the explosion chamber must be sealed and can only be excited in water, and the excitation energy is insufficient, making it unsuitable for micro-well logging production under near-surface conditions such as loess plateaus and deserts with loose formation media and thick low-velocity drop layers.

[0004] In summary, the problems existing in the prior art are as follows: 1. When using explosive sources for ground excitation, the progress of micro-well logging ground excitation construction is seriously affected due to problems such as strict explosive control. 2. When using non-explosive sources for ground excitation, there are problems of high equipment cost and low scope of application. In order to solve the problems existing in the prior art, this case is specially proposed to solve them. Utility Model Content

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the utility model provides a micro-well logging excitation device, which solves the problems raised in the above background technology.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the utility model is implemented through the following technical solutions: a micro-well logging excitation device, including a detector string lowered into the micro-well logging by a rope and a seismograph arranged on the surface, the detector string including at least one first detector, at least one of the first detectors being electrically connected to the seismograph through a two-core cable; a micro-well logging excitation device also includes a gun excitation component fixedly installed on the surface soil layer near the micro-well logging; the gun excitation component includes a disc, a sleeve, a gun, two detector cores, and three iron rods, the upper end of the sleeve is fixedly connected to the middle lower surface of the sleeve, the gun is arranged inside the sleeve, the three iron rods penetrate the disc, and the iron rod is threadedly connected to the disc, and the two detector cores are fixedly installed on the upper surface of the disc; the free end of the two-core cable of one of the detector cores is electrically connected to the trigger port of the seismograph, and the free end of the two-core cable of the other detector core is electrically connected to the acquisition port of the seismograph.

[0009] Optionally, a remote control igniter is installed on the upper surface of the disc, and a plug is threadedly connected in the middle of the disc and located above the sleeve. A round hole is opened in the middle of the plug, and the fuse on the firecracker passes through the round hole, and the end of the fuse is located at the ignition point of the remote control igniter.

[0010] Optionally, two fixing tubes are fixedly connected to the upper surface of the disc, and a fastening bolt that passes through the wall is threadedly connected to the side wall of each fixing tube; the two detector cores are respectively placed in the two fixing tubes, and the detector cores are detachably installed in the fixing tubes by fastening bolts.

[0011] Optionally, a nut is threadedly connected to the disc, a rotary handle is fixedly connected to the upper outer wall of the nut, the iron bar passes through the nut and the two are threadedly connected.

[0012] (III) Beneficial effects

[0013] The utility model provides a micro-well logging excitation device, which has the following beneficial effects:

[0014] 1. The micro-well logging excitation device has the effect of excitation of the ground source near the micro-well logging through the setting of the gun excitation component. A pit is dug on the hard soil layer on the surface, and a firecracker is placed in the pit. The iron rod is inserted into the surface soil, so that the disc drives the sleeve to cover the firecracker. The firecracker is only fixed on the hard soil on the surface through the cooperation of the iron rod, the disc and the sleeve. The firecracker is ignited and used as an energy source, thereby realizing low-cost surface source excitation. Compared with the existing technology, the firecracker is easy to obtain, low-cost, and does not affect the construction progress of the micro-well logging ground excitation. Moreover, the firecracker has a wide range of applications and can be used in a variety of complex environments.

[0015] 2. As a source of energy, firecrackers are of low risk and do not require complicated procedures for civil explosives or qualifications for explosives-related personnel, providing great convenience for construction.

[0016] 3. Through the coordinated setting of two detector cores and the seismograph, the firecrackers cause great vibration to the two detector cores after the explosion. The current generated by the vibration of the detector core is used to trigger the seismograph, avoiding the delay problem of the excitation system caused by the on and off triggering of the loop current when the heavy hammer and detonator are excited, thereby improving the measurement accuracy.

[0017] 4. Through the coordinated arrangement of the disc, sleeve and firecrackers, the energy of the seismic wave excited by the explosion of the firecrackers propagates upward and is reflected by the top surface of the plug. The energy reflected downward by the seismic wave is superimposed on the downward energy, which enhances the energy conversion efficiency and improves the recording signal-to-noise ratio. At the same time, the excitation energy in the downward direction is strengthened, solving the problem of insufficient excitation energy under near-surface conditions such as loess plateaus and deserts.

[0018] 5. The micro-well logging excitation device shown in the present application is simple to manufacture, low in manufacturing cost, light in weight, easy to carry, and can adapt to the excitation of various surface conditions, bringing great convenience to construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0020] Figure 1 This is a three-dimensional structural schematic diagram of a gun excitation component of a micro-well logging excitation device of the utility model (top view);

[0021] Figure 2 This is a three-dimensional structural schematic diagram of a gun excitation component of a micro-well logging excitation device of the utility model (looking from above);

[0022] Figure 3 The utility model is a structural schematic diagram of a micro-well logging excitation device when it is implemented at a micro-well logging location.

[0023] In the figure: 1. disc; 2. iron rod; 3. sleeve; 4. nut; 5. fixing tube; 6. detector core; 7. fastening bolt; 8. firecracker; 9. remote control igniter; 10. gun primer; 11. round hole; 12. gun excitation component; 13. micro well logging; 14. first detector; 15. seismograph. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indications or implications.

[0025] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments.

[0026] See also Figures 1 to 3 The utility model provides a technical solution: a micro-well logging excitation device, including a detector string lowered into a micro-well logging 13 by a rope, and a seismograph 15 arranged on the surface, the detector string including at least one first detector 14, and at least one first detector 14 is electrically connected to the seismograph 15 by a two-core cable. A micro-well logging excitation device also includes a cannon excitation component 12 fixedly installed on the surface soil layer near the micro-well logging 13.

[0027] The gun excitation component 12 includes a disc 1, a sleeve 3, a firecracker 8, two detector cores 6, and three iron rods 2. The upper end of the sleeve 3 is fixedly connected to the lower surface of the middle part of the sleeve 3, the firecracker 8 is arranged inside the sleeve 3, the three iron rods 2 penetrate the disc 1, and the iron rods 2 are threadedly connected to the disc 1, and the two detector cores 6 are fixedly installed on the upper surface of the disc 1. The free end of the two-core cable of one detector core 6 (referring to the end away from the detector core 6) is electrically connected (including communication connection) to the trigger port (or trigger interface) of the seismograph 15, and the free end of the two-core cable of the other detector core 6 is electrically connected (including communication connection) to the collection port (or collection interface) of the seismograph 15.

[0028] Among them, the detector string refers to at least one first detector 14, and also refers to multiple first detectors 14 electrically connected in parallel through multiple two-core cables, and there is a certain distance between each first detector 14. The seismograph 15 is used to collect seismic signals. After the detector string is lowered into the micro-well logging 13, the first detector 14 on the detector string is in close contact with the wall of the micro-well logging 13. The gun excitation component 12 is used to perform source excitation on the surface soil layer near the micro-well logging 13. The first detector 14 is used to detect the seismic wave signal generated by the surface gun excitation component 12 in the micro-well logging 13, and transmit the detected seismic signal to the seismograph 15.

[0029] In the cannon excitation component 12: the firecracker 8 is used to achieve source excitation through explosion; the two detector cores 6 generate electrical signals after being affected by the explosion vibration of the firecracker 8. One electrical signal is transmitted to the trigger port of the seismograph 15, triggering the seismograph 15 to start and collect seismic signals, and the other electrical signal is transmitted to the collection port of the seismograph 15 to collect the seismic signal at that moment. The disc 1 and the sleeve 3 are used to cover the firecracker 8 so that the firecracker 8 is fully in contact with the ground soil. Each iron rod 2 is used to fix the disc 1 on the ground soil layer. The iron rod 2 makes the entire cannon excitation component 12 tightly connected to the stratum, and it cannot fall off due to the explosion of the firecracker 8, and it cannot fly up and injure people.

[0030] If the detector string cannot cover the entire micro-logging section 13, the detector string is lifted up, and the above excitation and receiving operations are repeated, and the receiving is performed in sections until the micro-logging data collection of all sections is completed.

[0031] Specifically, a remote control igniter 9 is installed on the upper surface of the disc 1, and a plug is threadedly connected in the middle of the disc 1 and located above the sleeve 3. A circular hole 11 is opened in the middle of the plug, and a fuse 10 on the firecracker 8 passes through the circular hole 11, and the end of the fuse 10 is located at the ignition point of the remote control igniter 9.

[0032] The remote control igniter 9 can be, for example, a remote control tungsten filament igniter charged by a lighter, and the remote control igniter 9 is used to remotely ignite the primer 10 on the firecracker 8, so that the firecracker 8 explodes after being ignited.

[0033] Specifically, two fixing tubes 5 are fixedly connected to the upper surface of the disc 1, and a fastening bolt 7 is threadedly connected to the side wall of each fixing tube 5. Two detector cores 6 are respectively placed in the two fixing tubes 5, and the detector cores 6 are detachably installed in the fixing tubes 5 by the fastening bolts 7.

[0034] The fixing tube 5 is used to hold and fix the detector core 6. After the detector core 6 is placed in the fixing tube 5, the fastening bolt 7 is rotated so that the end of the fastening bolt 7 is pressed against the detector core 6 in the fixing tube 5.

[0035] Specifically, a nut 4 is threadedly connected to the disc 1, a rotating handle is fixedly connected to the upper outer wall of the nut 4, and the iron bar 2 passes through the nut 4 and the two are threadedly connected.

[0036] The nut 4 is threadedly connected to the iron rod 2, and the lower edge of the handle is slightly higher than the lower edge of the nut 4. The inside of the nut 4 is threadedly connected to the iron rod 2, and the outside of the nut 4 is threadedly connected to the disc 1. When the nut 4 is rotated to move downward relative to the iron rod 2, the nut 4 pushes the disc 1 downward, so that the disc 1 is close to the ground.

[0037] The seismograph trigger line is a two-core cable, one end of which is welded to the positive and negative terminals of the detector core 6, and the other end is electrically connected to the trigger interface of the seismograph 15. When the firecracker 8 explodes, it drives the detector core 6 to vibrate and generate an electrical signal, triggering the seismograph 15 to record the earthquake signal as the zero time.

[0038] The signal acquisition line is a two-core cable, one end of which is welded to the positive and negative terminals of the detector core 6, and the other end is electrically connected to the acquisition interface of the seismograph 15 to record the seismic signal of the explosion vibration of the firecracker 8. Under normal circumstances, the starting time of the signal is zero, which verifies that there is no delay in the recording system of the seismograph 15. If there is an abnormal delay, the delay time is read to correct the seismic channel record in the micro-well logging 13, and qualified seismic records can also be obtained. Furthermore, the trigger line and the acquisition line can be interchangeable to collect the signal of one of the detector cores 6. The main purpose is to verify whether the record is at zero time and whether there is a delay in the recording system of the seismograph 15. If there is a delay, set it as Δt, and the first arrival time read by each channel of the detector string is t 、i , then the real first arrival time of the track is t i =t 、i -Δt, i is the channel number of the detector string.

[0039] When in use, under sandy surface conditions, the installation of the cannon excitation component 12 is as follows: remove the surface soil at the excitation point and level it, dig a small hole in the middle to reserve space for the sleeve 3, place the disc 1, and the central circular hole 11 faces the small hole. Three iron rods 2 penetrate the disc 1 and nail it into the stratum respectively. By screwing the nut 4, the disc 1 is close to the surface. Put the firecracker 8 into the sleeve 3, and the gun lead 10 passes through the circular hole 11 on the plug. The plug is screwed into the disc 1 (the two are threadedly connected). The gun lead 10 is connected to the ignition end of the remote control igniter 9. Put the two detector cores 6 into the fixed tube 5 respectively, rotate the fastening bolts 7, and use the fastening bolts 7 to fix the detector core 6 in the fixed tube 5. The free end of the two-core cable of one detector core 6 (referring to the end away from the detector core 6) is electrically connected (including communication connection) to the trigger port (or trigger interface) of the seismograph 15, and the free end of the two-core cable of the other detector core 6 is electrically connected (including communication connection) to the acquisition port (or acquisition interface) of the seismograph 15.

[0040] Under rocky surface conditions, the installation of the blasting component 12 is as follows: fill the ground with soil at the excitation point, place a 20cm high iron ring or a concrete tube with a certain strength, fill the iron ring with soil, dig a small hole in the middle to reserve space for the plug, place the disc 1, and use a heavy object instead of the iron rod 2 to press the disc 1. The other steps are the same as above.

[0041] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A micro-well logging excitation device, characterized in that: The invention comprises a detector string lowered into a micro-well (13) by a rope and a seismograph (15) arranged on the surface, wherein the detector string comprises at least one first detector (14), and at least one of the first detectors (14) is electrically connected to the seismograph (15) by a two-core cable; and further comprises a gun excitation component (12) fixedly installed on the surface soil layer near the micro-well (13); The cannon excitation component (12) comprises a disc (1), a sleeve (3), a firecracker (8), two detector cores (6), and three iron rods (2); the upper end of the sleeve (3) is fixedly connected to the lower surface of the middle part of the sleeve (3); the firecracker (8) is arranged inside the sleeve (3); the three iron rods (2) penetrate the disc (1), and the iron rods (2) are threadedly connected to the disc (1); the two detector cores (6) are fixedly installed on the upper surface of the disc (1); the free end of the two-core cable of one of the detector cores (6) is electrically connected to the trigger port of the seismograph (15), and the free end of the two-core cable of the other detector core (6) is electrically connected to the collection port of the seismograph (15).

2. A micro-well logging excitation device according to claim 1, characterized in that: A remote control igniter (9) is installed on the upper surface of the disc (1), a plug is threadedly connected in the middle of the disc (1) and located above the sleeve (3), a round hole (11) is opened in the middle of the plug, a fuse (10) on the firecracker (8) passes through the round hole (11), and the end of the fuse (10) is located at the ignition point of the remote control igniter (9).

3. A micro-well logging excitation device according to claim 1, characterized in that: Two fixing tubes (5) are fixedly connected to the upper surface of the disc (1), and a fastening bolt (7) is threadedly connected to the side wall of each fixing tube (5) and penetrates the wall; the two detector cores (6) are respectively placed in the two fixing tubes (5), and the detector cores (6) are detachably installed in the fixing tubes (5) via the fastening bolts (7).

4. A micro-well logging excitation device according to claim 1, characterized in that: The disc (1) is threadedly connected with a nut (4), an upper outer wall of the nut (4) is fixedly connected with a rotary handle, and the iron bar (2) passes through the nut (4) and the two are threadedly connected.

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