A directional seismic source excitation device and a seismic data acquisition method

Abstract

This invention provides a directional seismic source excitation device and a seismic data acquisition method, comprising: a top cover, installed on the upper end of the device, to restrict the upward transmission of energy from an explosive seismic source or other seismic source capable of generating explosive force; a middle tube, located in the middle of the device, containing the seismic source; a bottom plate, also located in the middle of the device, containing the explosive seismic source or other seismic source capable of generating explosive force, with grooves created to form weak points, guiding the energy of the explosive seismic source or other seismic source capable of generating explosive force to penetrate the bottom plate along the inner circle of the grooves; a guide tube, restricting the circumferential transmission of the energy after blasting and the mass block of the breached bottom plate; a cap, located at the bottom of the device, to prevent mud and sand from entering the guide tube during the process of lowering the device into a well; and fastening bolts for securing the top cover and the middle tube. By using the explosive force generated in the seismic source cavity to impact the weak points of the bottom plate of the seismic source device, the bottom plate detaches from the device at the weak points, achieving the purpose of directional seismic source excitation.

Description

Technical Field

[0001] This invention relates to the field of excitation methods for seismic exploration sources in geophysical exploration technology, and more specifically, to a directional source excitation device and a seismic data acquisition method. Background Technology

[0002] Seismic waves in seismic exploration are artificially generated. Artificial seismic sources are generally divided into two main types: explosive sources and non-explosive sources. Explosive sources mainly use solid explosives, detonators, and physical explosions (air guns, electric sparks, hammers, etc.), but each method has relatively limited excitation range and operating conditions.

[0003] Explosive seismic sources, as traditional sources in the seismic exploration industry, generate pulse signals with strong excitation energy and a wide spectrum. However, the excitation effect of explosive seismic sources is affected by geological conditions, the energy is not easy to control, the energy utilization rate is low, the destructiveness is high, and the construction is dangerous.

[0004] During the exploration and construction of explosive seismic sources, after the explosive seismic source charge is lowered into the well, the charge directly contacts the inner wall of the well in the circumferential direction. The upper end of the charge and the wellhead are filled with soil and rocks to bury it. The purpose is to use the inner wall of the well and the soil and rocks filling the well to restrict the circumferential diffusion and upward movement of energy during the blasting of the explosive seismic source charge, thereby improving the downward transmission rate of the blasting energy of the explosive seismic source charge.

[0005] However, in some soft Gobi and gravel strata, well drilling is difficult. The inner wall of the well and the soil and rocks filling the well cannot effectively limit the circumferential diffusion and upward movement of energy during the detonation of the explosive source charge, resulting in poor excitation quality of the explosive source in these exploration areas. Summary of the Invention

[0006] The purpose of this invention is to provide a directional seismic source excitation device and a seismic data acquisition method for seismic exploration or surface investigation. By limiting the lateral and upward transmission of blasting energy from explosive sources or other sources capable of generating explosive force, the energy is guided downward, effectively improving the quality of the seismic excitation wavelet.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A directional seismic source excitation device mainly includes a top cover, which is installed on the upper end of the device to restrict the upward transmission of energy from explosive sources or other sources that can generate explosive force.

[0009] The central tube, located in the middle of the device, contains the explosive source or other sources capable of generating explosive force.

[0010] Fastening bolts are used to fasten the top cover and the middle tube; however, the connection between the top cover and the middle tube may use other connection methods such as welding, depending on the different internal sources that generate explosive force.

[0011] The base plate, located in the middle of the device, holds the explosive source or other sources capable of generating explosive force. Grooves are created to form weak points, guiding the energy of the explosive source or other sources capable of generating explosive force to break through the base plate along the inner circle of the grooves.

[0012] The guide tube limits the circumferential transmission of the energy after the explosion and the impact force of the broken base plate mass block;

[0013] The cap, located at the bottom of the device, prevents mud and sand from entering the guide pipe during the process of lowering the device into the wellbore.

[0014] The base plate has double-sided annular grooves and a propellant loading groove. The base plate is 30-50 mm thick, and the width of the double-sided annular grooves is 5-8 mm. After the grooves are cut on both sides, the remaining thickness of the base plate at the bottom of the grooves is 4-5 mm. The diameter of the propellant loading groove on the upper surface of the base plate is 70-80 mm, and the groove depth is 8-10 mm.

[0015] The mass of the mass block that separates from the bottom plate along the inner side of the double-sided annular groove is 3 to 4 kilograms.

[0016] The length of the guide tube is 300-350 mm.

[0017] The wall thickness of the middle tube is 12-16 mm.

[0018] The fastening bolts are M8-M10 in size and 40-45 mm in length.

[0019] The directional seismic source excitation device utilizes an upper cover, middle pipe, bottom plate, guide pipe, cap, and connecting bolts to form a semi-closed space with an overall wall thickness of 12-16 mm and a local thickness of 4-5 mm. Explosive sources or other sources capable of generating blasting force are placed within this semi-closed space. The design of side sealing and top pressure effectively restricts the circumferential diffusion and upward transmission of explosive energy. The blasting energy from the explosive source or other sources is guided downwards to impact the weak points in the slotted bottom plate. Under the action of the blasting force, the bottom plate bursts open from the slot, forming a directional and controllable excitation. Simultaneously, the guide pipe guides and restricts the lateral transmission of energy to the downward-moving shock wave and the mass block of the bottom plate after the blast, ensuring that most of the blasting energy and the mass block act vertically on the bottom surface, maximizing the use of blasting energy for longitudinal wave excitation.

[0020] The directional seismic source excitation device also includes an explosive machine that controls the detonation of the explosive source. This explosive machine also has a wireless signal transmission module, which is used to transmit the current pulse signal of the detonator connected inside the explosive to the seismic data acquisition instrument for synchronous seismic data acquisition.

[0021] The directional seismic source excitation device, which is deployed or buried underground in a specified direction and orientation, will generate seismic waves that propagate underground in the specified direction and orientation, thereby realizing directional seismic exploration.

[0022] The seismic data acquisition method using a directional source excitation device includes the following steps:

[0023] S1. Within the seismic exploration area, geophones are deployed according to the position of each geophone on all geophone survey lines laid out in the construction design, forming an exploration acquisition array.

[0024] S2. Within the seismic exploration area, according to the location of the well-shot source points on the seismic source line laid out in the construction design, well-shot drilling operations are carried out based on parameters such as the designed well depth and well diameter.

[0025] S3. Drilling a vertical borehole at the location of the borehole source point will generate seismic waves propagating vertically downwards using a directional seismic source device buried in the vertical borehole. Drilling a horizontal borehole or digging a horizontal trench at the location of the borehole source point will generate seismic waves propagating horizontally using a directional seismic source device buried in the horizontal borehole or horizontal trench. If a directional borehole is drilled in a specified direction and azimuth underground, the directional seismic source device buried in the directional borehole will generate seismic waves propagating in the specified direction and azimuth underground, thus achieving directional seismic exploration.

[0026] S4. Assembly of the directional seismic source excitation device and explosive charge: First, place the explosive charge into the middle tube, ensuring the tail end of the explosive charge contacts the groove on the base plate. Then, place the top cover into the middle tube, with the inner ring of the top cover pressing against the upper end face of the explosive charge. Finally, use bolts to connect and secure the top cover and the middle tube. Next, insert the sealing cap into the guide tube. Assembly is now complete.

[0027] S5. Place the detonator into the explosive charge, then place the directional seismic source activation device containing the explosive charge and detonator into the borehole of the well-fired seismic source. Cover the borehole with soil and compact the soil. Detonate according to the explosive source exploration and construction process. Simultaneously with detonating the explosive source, the detonator transmits the pulse current signal from the detonator inside the explosive charge to the seismic data acquisition instrument via a wireless signal transmission module, facilitating synchronous seismic data acquisition by the seismic data acquisition instrument.

[0028] S6. Following steps S1 to S4, sequentially deploy directional seismic source excitation devices in the wellbore of each seismic source point within the seismic exploration area, and collect artificial seismic wave data excited by the directional seismic source excitation devices at this seismic source point.

[0029] S7. Process the collected artificial seismic data to obtain reflected wave imaging data volume, and use the reflected wave imaging data volume to perform fine structural interpretation of underground geological bodies.

[0030] S8. Perform inversion processing on the collected data, extract relevant attributes, and conduct comprehensive prediction, evaluation, and quantitative interpretation of fluid distribution within underground geological bodies and oil and gas reservoirs.

[0031] The beneficial effects of this invention are: by using an external device to limit the lateral and upward transmission of explosive energy from the explosive source or other sources that can generate explosive force, and to guide the energy downward, without changing the existing state of the explosive, the effect of the metal block hammering is added to the explosive force, which can effectively improve the quality of the seismic excitation wavelet and improve the quality of seismic acquisition. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the directional seismic source excitation device of the present invention;

[0033] Figure 2 This is a schematic diagram of the slotted bottom plate of the directional seismic source excitation device of the present invention;

[0034] Figure 3 This is a schematic diagram of the guide tube of the directional seismic source excitation device of the present invention;

[0035] Figure 4 This is a schematic diagram of the directional seismic source excitation device and propellant charge installation of the present invention;

[0036] Figure 5 This is a schematic diagram of the directional seismic source excitation device of the present invention. Detailed Implementation

[0037] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, these embodiments do not constitute a limitation of the present invention and are merely examples. The advantages of the present invention will become clearer and easier to understand by describing them.

[0038] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative effort should all fall within the protection scope of the present invention.

[0039] The following is an example of the directional seismic source excitation device and seismic data acquisition method of the present invention.

[0040] Figure 1 This is a schematic diagram of the directional seismic source excitation device of the present invention. Figure 2 This is a schematic diagram of the slotted bottom plate of the directional seismic source excitation device of the present invention. Figure 3This is a schematic diagram of the guide tube of the directional seismic source excitation device of the present invention. The directional seismic source excitation device provided by the present invention mainly includes an upper cover 1, which is installed at the upper end of the device to restrict the upward transmission of energy from the explosive seismic source or other seismic sources capable of generating explosive force; a middle tube 2, located in the middle of the device, which holds the explosive seismic source or other seismic sources capable of generating explosive force; a bottom plate 3, located in the middle of the device, which holds the explosive seismic source or other seismic sources capable of generating explosive force, with grooves to create weak points, guiding the energy of the explosive seismic source or other seismic sources capable of generating explosive force to break through the bottom plate along the inner circle of the grooves; a guide tube 4, which restricts the circumferential transmission of the energy after blasting and the mass block 34 of the broken bottom plate; a sealing cover 5, located at the bottom of the device, which prevents mud and sand from entering the guide tube during the process of lowering the device into the well hole; and fastening bolts 6, used to fasten the upper cover and the middle tube.

[0041] The base plate 3 has an upper annular groove 31 on its upper end face, a lower annular groove 32 on its lower end face, and a medicine column mounting groove 33 in the middle of its upper end face.

[0042] The base plate 3 is 30-50 mm thick, and the upper annular groove 31 and the lower annular groove 32 are both 5-8 mm wide. After opening the annular grooves on both sides, the bottom thickness of the base plate is 4-5 mm.

[0043] The diameter of the drug cartridge mounting groove 33 is between 70 and 80 mm, and the groove depth is between 8 and 10 mm; after activation, the mass block 34, which separates from the bottom plate along the inner side of the double-sided annular groove, has a mass of 3 to 4 kg; the wall thickness of the middle tube 2 is between 12 and 16 mm.

[0044] Figure 4 , Figure 5 This demonstrates how the invention is applied in seismic exploration. The directional seismic source excitation device mainly includes an upper cover 1, a middle tube 2, a base plate 3, a guide tube 4, a sealing cap 5, and fastening bolts 6. The upper cover 1 and the middle tube 2 are fixedly connected by bolts. The middle tube 2 and the guide tube 4 are welded to both sides of the base plate 3. Circular closed grooves are milled into both sides of the base plate 3; the sealed portion within the grooves is the weak point of the device. The sealing cap 5 is a plastic sleeve that fits tightly against the outer wall of the guide tube 4, providing a sealing function. Figure 2 , Figure 3 The illustrated embodiment demonstrates the installation and activation process of the directional seismic source excitation device and the explosive charge.

[0045] The directional seismic source excitation device also includes an explosive machine that controls the detonation of the explosive source. This explosive machine also has a wireless signal transmission module, which is used to transmit the current pulse signal of the detonator connected inside the explosive to the seismic data acquisition instrument for synchronous seismic data acquisition.

[0046] The seismic data acquisition method using a directional source excitation device includes the following steps:

[0047] S1. Within the seismic exploration area, geophones are deployed according to the position of each geophone on all geophone survey lines laid out in the construction design, forming an exploration acquisition array.

[0048] S2. Within the seismic exploration area, according to the location of the well-shot source points on the seismic source line laid out in the construction design, well-shot drilling operations are carried out based on parameters such as the designed well depth and well diameter.

[0049] S3. Drilling a vertical borehole at the location of the borehole source point will generate seismic waves propagating vertically downwards using a directional seismic source device buried in the vertical borehole. Drilling a horizontal borehole or digging a horizontal trench at the location of the borehole source point will generate seismic waves propagating horizontally using a directional seismic source device buried in the horizontal borehole or horizontal trench. If a directional borehole is drilled in a specified direction and azimuth underground, the directional seismic source device buried in the directional borehole will generate seismic waves propagating in the specified direction and azimuth underground, thus achieving directional seismic exploration.

[0050] S4. Assembly of the directional seismic source excitation device and the explosive charge: First, place the explosive charge 7 into the middle tube 2, with the tail of the explosive charge 7 contacting the groove on the base plate 3. Then, place the upper cover 1 into the middle tube 2, with the inner ring surface of the upper cover 1 pressing against the upper end face of the explosive charge 7. Finally, use bolts 6 to connect and tighten the upper cover 1 and the middle tube 2. Next, insert the sealing cap 5 into the guide tube 4. Assembly is complete.

[0051] S5. Place the detonator 8 into the explosive charge 7, then place the directional seismic source excitation device containing the explosive charge 7 and the detonator 8 into the borehole of the well-fired seismic source, and cover and compact the well with soil and rock. Detonate according to the explosive source exploration and construction process. At the same time as detonating the explosive source, the detonator transmits the pulse current signal of the detonator inside the explosive to the seismic data acquisition instrument through a wireless signal transmission module, facilitating synchronous seismic data acquisition by the seismic data acquisition instrument.

[0052] S6. Following steps S1 to S4, sequentially deploy directional seismic source excitation devices in the wellbore of each seismic source point within the seismic exploration area, and collect artificial seismic wave data excited by the directional seismic source excitation devices at this seismic source point.

[0053] S7. Process the collected artificial seismic data to obtain reflected wave imaging data volume, and use the reflected wave imaging data volume to perform fine structural interpretation of underground geological bodies.

[0054] S8. Perform inversion processing on the collected data, extract relevant attributes, and conduct comprehensive prediction, evaluation, and quantitative interpretation of fluid distribution within underground geological bodies and oil and gas reservoirs.

[0055] All other parts not described in detail are existing technology.

Claims

1. A directional seismic source excitation device, characterized in that, include: The top cover (1) restricts the upward transmission of energy from the explosive source or other sources that can generate explosive force; The middle tube (2) contains the explosive source or other sources that can generate explosive force; The top cover (1) is fixedly installed on the top of the middle tube (2); The bottom plate (3) is located in the lower part of the middle tube (2) and is used to hold the seismic source; The base plate (3) has an upper annular groove (31) on its upper end face, a lower annular groove (32) on its lower end face, and a medicine column mounting groove (33) in the middle of its upper end face. The bottom plate (3) is 30-50 mm thick, and the width of the upper annular groove (31) and the lower annular groove (32) is 5-8 mm. After opening the annular grooves on both sides, the bottom thickness of the bottom plate (3) is 4-5 mm. The diameter of the drug column mounting groove (33) is between 70 and 80 mm, and the groove depth is 8 to 10 mm; after activation, the mass block (34) that separates from the bottom plate along the inner side of the double-sided annular groove of the bottom plate has a mass of 3 to 4 kg; the wall thickness of the middle tube (2) is 12 to 16 mm; The lower end of the middle tube (2) also includes a guide tube (4) to limit the energy after the explosion and the impact force of the broken bottom plate mass block (34) to be transmitted circumferentially; The bottom of the guide tube (4) is also fitted with a cap (5) to prevent debris from entering the guide tube (4).

2. The directional seismic source excitation device according to claim 1, characterized in that, It also includes an explosive device for controlling the detonation of the explosive source, wherein the explosive device includes a wireless signal transmission module for transmitting the current pulse signal of the detonator connected inside the explosive to the seismic data acquisition instrument for synchronous seismic data acquisition.

3. The seismic data acquisition method for the directional source excitation device according to claim 1 or 2, characterized in that, Includes the following steps: S1. Within the seismic exploration area, geophones are deployed according to the position of each geophone on all geophone survey lines laid out in the construction design, forming an exploration acquisition array. S2. Within the seismic exploration area, according to the location of the well-shot source points on the seismic source line laid out in the construction design, well-shot drilling operations are carried out based on parameters such as the designed well depth and well diameter. S3. Drilling a vertical borehole at the location of the borehole source point will generate seismic waves propagating vertically downwards using a directional seismic source device buried in the vertical borehole. Drilling a horizontal borehole or digging a horizontal trench at the location of the borehole source point will generate seismic waves propagating horizontally using a directional seismic source device buried in the horizontal borehole or horizontal trench. If a directional borehole is drilled in a specified direction and azimuth underground, the directional seismic source device buried in the directional borehole will generate seismic waves propagating in the specified direction and azimuth underground, thus achieving directional seismic exploration. S4. Assembly of directional seismic source excitation device and explosive charge: First, put the explosive charge (7) into the middle tube (2), and the tail of the explosive charge (7) contacts the groove on the bottom plate (3). Then, put the top cover (1) into the middle tube (2), and press the inner ring surface of the top cover (1) against the upper end face of the explosive charge (7). Then, connect and tighten the top cover (1) and the middle tube (2). Then, put the sealing cover (5) into the guide tube (4) to complete the assembly. S5. Place the detonator (8) into the explosive charge (7), and then place the directional seismic source excitation device containing the explosive charge (7) and the detonator (8) into the wellbore of the well-fired seismic source. Cover the well with soil and stone and compact it. Detonate according to the explosive seismic source exploration and construction process. At the same time as detonating the explosive seismic source, the detonator transmits the pulse current signal of the detonator inside the explosive to the seismic data acquisition instrument through the wireless signal transmission module, so as to facilitate the seismic data acquisition instrument to carry out synchronous seismic data acquisition. S6. Following steps S1 to S4, sequentially deploy directional seismic source excitation devices in the wellbore of each seismic source point within the seismic exploration area, and collect artificial seismic wave data excited by the directional seismic source excitation devices at this seismic source point. S7. Process the collected artificial seismic data to obtain reflected wave imaging data volume, and use the reflected wave imaging data volume to perform fine structural interpretation of underground geological bodies. S8. Perform inversion processing on the collected data, extract relevant attributes, and conduct comprehensive prediction, evaluation, and quantitative interpretation of fluid distribution within underground geological bodies and oil and gas reservoirs.

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