Shallow seismic exploration system and exploration method thereof

Abstract

The invention relates to the technical field of shallow seismic exploration, and provides a shallow seismic exploration system, which comprises a seismic source vehicle and a plurality of detection units, and is characterized in that the seismic source vehicle drives the detection units to move through a traction rope; the plurality of detection units are sequentially connected through a winding belt; each detection unit is provided with a track distance adjusting module used for adjusting the extending length of the winding belt so as to change the track distance between the detection units. The system drives a plurality of detection units to move synchronously through the seismic source vehicle, workers do not need to move the detection units frequently, the situation that the data quality is affected by position deviation of detectors can be avoided, efficiency can be improved, meanwhile, the track distance between the detection units and the offset between the seismic source vehicle and the detection units can be adjusted according to needs, and the detection accuracy is improved. The system has the advantages of high efficiency, flexibility and variability; the invention further provides a shallow seismic exploration method suitable for the system. The shallow seismic exploration method has the advantages of being high in interference resistance, economical and capable of comprehensively reflecting geologic structure information characteristics of a measurement area.

Description

Technical Field

[0001] The present application relates to the technical field of shallow seismic exploration, and specifically to a shallow seismic exploration system and an exploration method thereof. Background Art

[0002] Seismic exploration refers to a geophysical exploration method that uses the difference in wave velocity of elastic waves caused by artificial excitation due to the elasticity and density of underground media to infer the properties and morphology of underground rock formations by observing and analyzing the propagation patterns of seismic waves generated by artificial earthquakes underground.

[0003] The conventional field operation process of existing shallow seismic exploration technology is to arrange seismic detectors one by one at a certain distance on the road surface to form an observation array according to the test depth and resolution requirements, and then manually excite the seismic signal. After the single-shot data acquisition is completed, the next observation array needs to be rearranged. However, the detectors are prone to position deviation during the movement process, which affects the data quality, and the back-and-forth movement of personnel consumes a lot of time. In addition, due to the limited power of artificial excitation, it can usually only reach a depth of 20 meters at most, so the range of the observation array must be less than 20 meters. If the distance is too large, the detectors far away from the source will not receive the seismic signal.

[0004] CN111913214A discloses a towed shallow seismic data acquisition chain and a seismic data acquisition system, comprising a towing belt, a connecting belt and a plurality of detector units sequentially distributed along the towing direction, wherein the connecting belt is detachably connected between two adjacent detector units, one end of the towing belt is connected to the detector unit at the head end, and the other end is used to connect to the source vehicle. The detector unit of the above scheme is detachably fixed by the connecting belt, so that it is convenient for the staff to adjust the track spacing of the acquisition chain, and can quickly adapt to most seismic data acquisition tasks.

[0005] Although the above scheme has accelerated the exploration rate to a certain extent, it still has some shortcomings. First of all, the offset distance (the distance from the excitation point to the first receiving point) of the above scheme is fixed. However, in actual exploration projects, engineers are usually required to adjust the offset distance based on geological conditions. The reason is that if the offset distance is too large, the most important reflection wave cannot reach the rated number of superpositions; if the offset distance is too small, the difference in time difference between the first and multiple reflections of the reflection wave is smaller than the value that it can distinguish. Secondly, the adjustment operation of the track distance (the distance between two adjacent receiving points) of the above scheme is relatively cumbersome, and it is difficult to ensure the consistency of length.

[0006] Based on this, the technical problem solved in this case is: how to solve the problem that the offset distance of the existing seismic exploration equipment cannot be adjusted, and at the same time further optimize the adjustment method of the track distance. Summary of the invention

[0007] In order to solve the above technical problems, the present application provides a shallow seismic exploration system. The system drives multiple detection units to move synchronously through a source vehicle, and there is no need for staff to frequently move the detection units. This can avoid position deviation of the detectors and affect data quality and improve efficiency. At the same time, the track spacing between the detection units and the shot spacing between the source vehicle and the detection units can be adjusted as needed, so that the system has the advantages of high efficiency and flexibility. The present application also provides a shallow seismic exploration method suitable for the above system, which has the advantages of strong anti-interference, economy and the ability to comprehensively reflect the geological structure information characteristics of the survey area.

[0008] The technical solution of this application is:

[0009] A shallow seismic exploration system comprises a source vehicle and a plurality of detection units, wherein the source vehicle drives the detection units to move by means of a traction rope; the plurality of detection units are connected in sequence by means of a winding belt; the detection units are provided with a track spacing adjustment module for adjusting the extension length of the winding belt so as to change the track spacing between the detection units.

[0010] This system uses the source vehicle to drive multiple detection units to move synchronously, without the need for staff to frequently move the detection units, which can avoid the position deviation of the detectors and affect the data quality and improve efficiency. At the same time, the track spacing between the detection units and the shot spacing between the source vehicle and the detection units can be adjusted as needed, making this system efficient and flexible.

[0011] In the above-mentioned shallow seismic exploration system, the detection unit includes a base and a detector; the base is provided with a mounting portion, and the detector is arranged in the mounting portion; and the track spacing adjustment module is arranged on the base.

[0012] In the above-mentioned shallow seismic exploration system, the winding belt is a tape measure, and the track spacing adjustment module includes a shell and a limit buckle for fixing the extended length of the winding belt; the winding belt is arranged in the shell, and when the limit buckle is released, the winding belt shrinks into the shell.

[0013] In the above-mentioned shallow seismic exploration system, the winding belt is a flexible belt, and the track spacing adjustment module includes a roller shaft and a hand wheel for adjusting the extension length of the winding belt; one end of the winding belt is fixed on the roller shaft.

[0014] In the above-mentioned shallow seismic exploration system, the source vehicle is provided with an excitation module; the excitation module comprises a heavy hammer for excitation, a tractor for lifting the heavy hammer to a set height, and an electromagnetic suction component for fixing or releasing the heavy hammer at the set height;

[0015] The weight is provided with an excitation switch. When the weight contacts the ground, the excitation switch sends a first signal to enable an external timing device to record the current time.

[0016] In the above-mentioned shallow seismic exploration system, a plurality of pulleys are provided between the traction machine and the weight.

[0017] In the above-mentioned shallow seismic exploration system, the source vehicle is provided with a control module 4 to enable the traction machine and the electromagnetic suction component of the excitation module to work in coordination.

[0018] In the above-mentioned shallow seismic exploration system, the winding belt is provided with scale marks.

[0019] The present application also provides a shallow seismic exploration method, which is based on the above-mentioned shallow seismic exploration system, and a plurality of the detection units are arranged in parallel front and back, and includes the following steps:

[0020] Step 1: The track pitch is adjusted by adjusting the extension length of the take-up belt between each detection unit through the track pitch adjustment module to adjust the track pitch;

[0021] Step 2: Adjust the length of the towing rope to adjust the offset and the offset;

[0022] Step 3: The excitation module of the source vehicle works, the electromagnetic suction component loses power, the heavy hammer is released for excitation, the external timing device records the excitation time, each geophone records the seismic signal, the traction machine lifts the heavy hammer to the set height again and the electromagnetic suction component is powered on to fix the heavy hammer;

[0023] Step 4: The source vehicle moves forward to the next level of excitation point;

[0024] Step 5: Repeat steps 3 and 4 until the record is complete.

[0025] In the above shallow seismic exploration method, the track spacing in step 1 is 0.5-1 m; the offset distance in step 2 is 2-4 times of the track spacing; and the source vehicle in step 4 moves a distance equal to the track spacing each time.

[0026] One of the above technical solutions of the present application has at least one of the following advantages or beneficial effects:

[0027] The system of the present application drives multiple detection units to move synchronously through the source vehicle, eliminating the need for staff to frequently move the detection units, which can avoid position deviations of the detectors that affect data quality and improve efficiency. At the same time, the track spacing between the detection units and the shot spacing between the source vehicle and the detection units can be adjusted as needed, giving the system the advantages of high efficiency and flexibility.

[0028] In addition, the present application also provides a shallow seismic exploration method suitable for the above system, which has the advantages of strong anti-interference, economy and the ability to comprehensively reflect the geological structure information characteristics of the survey area. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the working principle diagram of this application;

[0030] Figure 2 This is a schematic diagram of the structure of the detection unit of the present application.

[0031] Wherein, the reference numerals are respectively:

[0032] 1. Detection unit; 11. Base; 12. Detector; 2. Track spacing adjustment module; 3. Excitation module; 31. Weight; 32. Traction machine; 33. Electromagnetic suction assembly; 34. Pulley; 4. Control module; 101. Winding belt; 201. Traction rope. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0034] Example 1

[0035] refer to Figure 1 , 2 A shallow seismic exploration system comprises a source vehicle and 30 detection units 1, wherein the source vehicle drives the detection units 1 to move via a traction rope 201; the 30 detection units 1 are connected in sequence via a winding belt 101; the detection units 1 are provided with a track spacing adjustment module 2 for adjusting the extension length of the winding belt 101 to change the track spacing between the detection units 1.

[0036] In actual application, 30 detection units 1 are arranged in parallel front and back, and engineers calculate the corresponding track distance and offset distance based on geological conditions and environmental factors.

[0037] The system of this embodiment drives 30 detection units 1 to move synchronously through the source vehicle, and there is no need for staff to frequently move the detection units 1. This can avoid the position deviation of the detector 12 and affect the data quality and improve efficiency. At the same time, the track spacing between the detection units 1 and the shot offset spacing between the source vehicle and the detection unit 1 can be adjusted as needed, so that the system has the advantages of high efficiency and flexibility. The application also provides a shallow seismic exploration method suitable for the above system, which has the advantages of strong anti-interference, economy and the ability to comprehensively reflect the geological structure information characteristics of the survey area.

[0038] Specifically, the detector unit 1 includes a base 11 and a detector 12; the base 11 is provided with a mounting portion, and the detector 12 is arranged in the mounting portion; the track distance adjustment module 2 is arranged on the base 11. Under this design, the detector 12 does not need to be buried on the road surface, so as to minimize the damage to the urban hardened road surface.

[0039] More specifically, the traction rope 201 in this embodiment is a textile belt, and its length is controlled by a winder, so as to achieve the purpose of adjusting the offset. In actual exploration projects, after engineers determine the required offset based on geological conditions, they can adjust it to a suitable offset through this system. Compared with traditional methods, the offset adjustment method of this system has the advantages of being fast and accurate.

[0040] In this embodiment, the winding belt 101 is a tape measure, and the track distance adjustment module 2 includes a housing and a limit buckle for fixing the extended length of the winding belt 101; the winding belt 101 is arranged in the housing, and when the limit buckle is released, the winding belt 101 shrinks into the housing. The working principle of the winding belt 101 in this embodiment can refer to the engineering tape measure.

[0041] In other embodiments, the winding belt 101 may also be a flexible belt, and the track distance adjustment module 2 includes a roller and a hand wheel for adjusting the extension length of the winding belt 101; one end of the winding belt 101 is fixed on the roller.

[0042] In actual application, in order to facilitate the staff to observe the length, the winding belt 101 is provided with scale marks.

[0043] In this embodiment, preferably, the source vehicle is provided with an excitation module 3; the excitation module 3 includes a weight 31 for excitation, a traction machine 32 for lifting the weight 31 to a set height, and an electromagnetic suction component 33 for fixing or releasing the weight 31 at the set height.

[0044] Further preferably, a pulley 34 for saving effort is provided between the traction machine 32 and the weight 31 .

[0045] Further preferably, the seismic source vehicle is provided with a control module 4 to enable the traction machine 32 and the electromagnetic suction assembly 33 of the excitation module 3 to work in coordination.

[0046] Example 2

[0047] A shallow seismic exploration method is based on the shallow seismic exploration system as described in Example 1, and the 20 detection units 1 are arranged in a straight line front to back; further explained, this embodiment is based on the need to remove hazards and reinforce the reservoir, and therefore, the detection and reinforcement effects of weak interlayers in rivers and reservoir dams (embankments) are evaluated by testing transient surface waves.

[0048] The steps include:

[0049] Step 1: The track spacing adjustment module 2 is used to adjust the extension length of the take-up belt 101 between each detection unit 1 to adjust the track spacing to 1 m;

[0050] Step 2: Adjust the length of the traction rope 201 to adjust the offset distance to 4m. At this time, the minimum offset is 4m and the maximum offset is 23m.

[0051] Step 3: The excitation module 3 of the source vehicle works, the electromagnetic suction component 33 loses power, the heavy hammer 31 is released for excitation, the external timing device records the excitation time, each detector 12 records the seismic signal, the traction machine 32 lifts the heavy hammer 31 to the set height again and the electromagnetic suction component 33 is powered to fix the heavy hammer 31; in this embodiment, it should be noted that in actual application, the set height and mass of the heavy hammer 31 can be determined according to the length of the gun offset to be detected, thereby overcoming the problem that the rear detector 12 cannot obtain the seismic signal due to insufficient excitation force, so that the system can detect seismic signals exceeding 20 meters.

[0052] Step 4: The source vehicle moves forward to the next excitation point. In this embodiment, the source vehicle moves 1 meter each time and adjusts the traction rope to ensure that the traction rope is in a relaxed state;

[0053] Step 5: Repeat steps 3 and 4 until the record is complete.

Claims

1. A shallow seismic exploration system, comprising a source vehicle and a plurality of detection units, characterized in that: The source vehicle drives the detection unit to move through a traction rope; a plurality of the detection units are connected in sequence through a winding belt; the detection unit is provided with a track spacing adjustment module for adjusting the extension length of the winding belt to change the track spacing between the detection units.

2. The shallow seismic exploration system according to claim 1, characterized in that: The detector unit comprises a base and a detector; the base is provided with a mounting portion, and the detector is arranged in the mounting portion; the track pitch adjustment module is arranged on the base.

3. The shallow seismic exploration system according to claim 1, characterized in that: The winding belt is a measuring tape, and the track distance adjustment module includes a shell and a limit buckle for fixing the extended length of the winding belt; the winding belt is arranged in the shell, and when the limit buckle is released, the winding belt shrinks into the shell.

4. The shallow seismic exploration system according to claim 1, characterized in that: The winding belt is a flexible belt, and the track distance adjustment module includes a roller shaft and a hand wheel for adjusting the extension length of the winding belt; one end of the winding belt is fixed on the roller shaft.

5. The shallow seismic exploration system according to claim 1, characterized in that: The seismic source vehicle is provided with an excitation module; the excitation module comprises a heavy hammer for excitation, a traction machine for lifting the heavy hammer to a set height, and an electromagnetic suction component for fixing or releasing the heavy hammer at the set height; The weight is provided with an excitation switch. When the weight contacts the ground, the excitation switch sends a first signal to enable an external timing device to record the current time.

6. The shallow seismic exploration system according to claim 5, characterized in that: A plurality of pulleys are arranged between the traction machine and the heavy hammer.

7. The shallow seismic exploration system according to claim 5, characterized in that: The seismic source vehicle is provided with a control module 4 to enable the traction machine and the electromagnetic suction component of the excitation module to work in coordination.

8. The shallow seismic exploration system according to claim 1, characterized in that: The winding belt is provided with scale marks.

9. A shallow seismic exploration method, characterized in that: Based on the shallow seismic exploration system according to any one of claims 1 to 8, wherein a plurality of said detection units are arranged in parallel front and back, the system comprises the following steps: Step 1: The track distance is adjusted by adjusting the extension length of the take-up belt between each detection unit through the track distance adjustment module to adjust the track distance; Step 2: Adjust the length of the towing rope to adjust the offset and the offset; Step 3: The excitation module of the source vehicle works, the electromagnetic suction component loses power, and the heavy hammer is released for excitation. When the heavy hammer contacts the ground, the excitation switch sends a first signal, so that the external timing device records the current time, and each detector records the seismic signal respectively. The traction machine lifts the heavy hammer to the set height again and the electromagnetic suction component is powered to fix the heavy hammer; Step 4: The source vehicle moves forward to the next level of excitation point; Step 5: Repeat steps 3 and 4 until the record is complete.

10. The shallow seismic exploration method according to claim 1, characterized in that: In step 1, the track spacing is 0.5 to 1 m; in step 2, the offset distance is 2 to 4 times the track spacing; in step 4, the source vehicle moves a distance equal to the track spacing each time.

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