A design method and device for delayed excitation charge with enhanced downward energy

Abstract

The embodiment of the present application is to provide a method and device for designing delayed excitation charges that enhance downward energy transmission, belonging to the field of geophysical engineering technology and equipment. The method includes the following steps: investigating the surface structure of the work area, obtaining surface structure data, and establishing a surface structure profile; obtaining seismic data and exploration data of the work area; determining the number of charge levels and the level spacing between each two adjacent explosive packages based on the surface structure data of the work area, the expected total charge amount, and the optimal single-stage charge amount; determining the delay time between each two adjacent explosive packages based on the level spacing and the excitation surrounding rock velocity between each two adjacent explosive packages; determining the length of the detonating cord between each two adjacent explosive packages based on the delay time between each two adjacent explosive packages; assembling each level of charge according to the length of the detonating cord between each two adjacent explosive packages and the number of charge levels, wherein each two adjacent explosive packages are connected by a detonating cord. The present application aims to improve the quality of seismic data.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of geophysical exploration engineering technology and equipment, and specifically, to a method and device for designing a delayed excitation charge for enhancing downward energy transmission. Background Art

[0002] As the degree of oil and gas exploration continues to increase, the requirements for seismic exploration accuracy are also getting higher and higher. According to records, the Fushan Sag in Hainan Province is located in the south-central part of the Beibu Gulf Basin. It is a Cenozoic rift basin with an area of ​​2920km 2 , its total oil resources are 3.01×10 8 t, and the total natural gas resources are 653.2×10 8 m 3 Exploration potential is significant. However, within the Fushan Sag in Hainan, igneous rocks are present over a large area at the surface, in the shallow Upper Tertiary layers, and within the Lower Tertiary, resulting in extremely poor seismic data quality in the area. Since 2003, a series of seismic exploration projects have significantly improved data quality and established an annual production capacity of 400,000 tons. However, seismic data still suffer from challenges such as low signal-to-noise ratio, which hinders oilfield exploration and development progress, necessitating an urgent need to improve data quality.

[0003] Since the critical angle between the volcanic rock and the overlying strata is very small, seismic waves with incident angles greater than or equal to the critical angle are converted into interference waves. Therefore, the energy of conventional excitation seismic waves converted into interference waves is much greater than the downward energy, causing scattering interference, energy shielding, and resulting in low quality of single-shot data. Summary of the Invention

[0004] The embodiments of the present application provide a method and device for designing a delayed excitation charge for enhancing down-conducting energy, aiming to suppress interference waves, enhance reflected signals, and increase down-conducting energy, thereby improving the quality of seismic data in igneous rock development areas.

[0005] In a first aspect, the present invention provides a method for designing a delayed-excitation charge with enhanced down-conducting energy, comprising the following steps:

[0006] Investigate the surface structure of the work area, obtain surface structure data, and establish a surface structure profile; the surface structure data includes the thickness of the igneous rock in the work area, the thickness of the underlying strata of the igneous rock, the velocity profile, and the velocity of the stimulated surrounding rock;

[0007] Obtain seismic data and exploration data in the work area, combine them with surface structure data, establish a velocity model, and perform forward modeling to determine the direction and frequency of the wave field excited by the secondary interference wave in the work area;

[0008] Determining the number of charge columns and the distance between each two adjacent explosive packages based on the surface structure data of the work area, the expected total charge amount and the optimal single-stage charge amount;

[0009] Determining the delay time between each two adjacent explosive packages according to the step spacing between each two adjacent explosive packages and the velocity of the excited surrounding rock;

[0010] Determine the length of the detonating cord between each two adjacent explosive packs based on the delay time between each two adjacent explosive packs;

[0011] According to the length of the detonating cord between each two adjacent explosive packs and the number and spacing of the explosive packs, the explosive packs of each level are assembled, wherein each two adjacent explosive packs are connected by the detonating cord.

[0012] Optionally, the determining of the number of charge columns and the distance between each two adjacent explosive cartridges based on the surface structure data of the work area, the expected total charge amount and the optimal single-stage charge amount includes:

[0013] Determine the total delay time based on the direction of the wave field excited by the secondary interference wave in the work area and the frequency of the secondary wave; the total delay time includes the difference in travel time of the seismic wave from the top and bottom of the delayed charge to the ground;

[0014] Determining the total length of the charge based on the difference in seismic wave travel time from the top and bottom of the delayed charge to the ground and the velocity of the excited surrounding rock;

[0015] Determine the number of charge columns and the length of a single-stage explosive package based on the desired total charge and the optimal single-stage charge.

[0016] The stage spacing between every two adjacent explosive cartridges is determined based on the total length of the explosive column, the number of stages of the explosive column and the length of a single-stage explosive cartridge.

[0017] Optionally, determining the delay time between each two adjacent explosive packs based on the step spacing between each two adjacent explosive packs and the velocity of the excited surrounding rock includes:

[0018] Based on the total delay time, obtaining an excitation time difference;

[0019] Obtaining the number of charge columns, the length of a single-stage explosive package, and the explosive package detonation velocity; determining the explosive package detonation time based on the number of charge columns, the length of a single-stage explosive package, and the explosive package detonation velocity;

[0020] Determining the detonation time of the detonating cord based on the excitation time difference and the detonation time of the explosive package;

[0021] The delay time between each two adjacent explosive packs is determined based on the detonation cord transmission time and the number of explosive columns.

[0022] Optionally, determining the length of the detonating cord between each two adjacent explosive packs based on the delay time between each two adjacent explosive packs includes:

[0023] Obtaining the detonation length of the explosive package and the detonation velocity of the detonating cord;

[0024] Determining the basic length of the detonating cord based on the detonation velocity of the detonating cord and the delay time between each two adjacent explosive packs;

[0025] The length of the detonating cord is determined based on the basic length of the detonating cord and the detonation length of the explosive cartridge.

[0026] Optionally, determining the total delay time based on the direction of the wave field excited by the secondary interference wave in the work area and the frequency of the secondary wave includes:

[0027] Based on the frequency of the secondary wave, the period of the secondary wave is obtained by using a relationship between period and frequency;

[0028] The total delay time is half of the secondary wave period.

[0029] Optionally, the total length of the charge is determined based on the difference in travel time of seismic waves from the top and bottom of the delayed charge to the ground and the velocity of the excited surrounding rock;

[0030] Use the following formula:

[0031] L = T1·V1;

[0032] Where L is the total length of the charge; T1 is the difference in travel time of the seismic wave from the top and bottom of the delayed charge to the ground; V1 is the velocity of the excited surrounding rock.

[0033] Optionally, the step spacing between each two adjacent explosive packages is determined based on the total length of the explosive column, the number of charge column stages and the length of a single-stage explosive package, using the following formula:

[0034] D = (L - L2·S) / (S-1);

[0035] Where D is the stage spacing; L is the total length of the explosive column; L2 is the length of a single-stage explosive package; and S is the number of explosive column stages.

[0036] Optionally, the explosive charge detonation time is determined based on the number of charge columns, the length of a single-stage explosive charge, and the explosive charge detonation velocity using the following formula:

[0037] T2=(L2·S) / V2;

[0038] Where, T2 is the explosive package detonation time; L2 is the length of a single-stage explosive package; V2 is the explosive package detonation velocity; S is the number of explosive column stages.

[0039] Optionally, a threaded tube is provided, the threaded tube being installed between two adjacent explosive packs, the detonating cord being wound around the threaded tube; the threaded tube being used to reduce the detonation velocity of the detonating cord between the two adjacent explosive packs to be consistent with the velocity of the excitation surrounding rock;

[0040] The length of the threaded tube is consistent with the step spacing between every two adjacent explosive packs;

[0041] The speed reduction ratio of the threaded tube is set based on the delay time between each two adjacent explosive packs and the step spacing between each two adjacent explosive packs.

[0042] In a second aspect, an embodiment of the present application provides a device for designing a delayed excitation charge for enhancing downward energy transmission, comprising:

[0043] The survey module is used to survey the surface structure of the work area, obtain surface structure data, and establish a surface structure profile; the surface structure data includes the thickness of the igneous rock in the work area, the thickness of the underlying strata of the igneous rock, the velocity profile, and the velocity of the stimulated surrounding rock;

[0044] The secondary wave acquisition module is used to obtain seismic data and exploration data in the work area, combine them with surface structure data, establish a velocity model, and perform forward modeling to determine the direction and frequency of the wave field excited by the secondary interference wave in the work area;

[0045] a step spacing determination module, which determines the number of charge columns and the step spacing between each two adjacent explosive packages based on the surface structure data of the work area, the expected total charge amount and the optimal single-stage charge amount;

[0046] a delay time determination module, which determines the delay time between each two adjacent explosive packages according to the step spacing between each two adjacent explosive packages and the velocity of the excited surrounding rock;

[0047] a detonating cord length determination module, which determines the length of the detonating cord between each two adjacent explosive packs based on the delay time between each two adjacent explosive packs;

[0048] The installation module is used to assemble each level of explosive column according to the length of the detonating cord between each adjacent two explosive packets and the number of the explosive column stages and the stage spacing, wherein each adjacent two explosive packets are connected by the detonating cord.

[0049] Beneficial effects: Based on the surface structure of the work area obtained through investigation, the seismic data and exploration data of the work area obtained are combined, and based on the direction and frequency of the wave field excited by the secondary interference wave in the work area, the detonating cord length and delay time of the multi-stage charge are calculated, and the multi-stage charge excitation is designed. The energy generated after the multi-stage charge is excited is directional and can be superimposed and strengthened directly below to effectively weaken the secondary wave interference generated by the excitation and enhance the downward energy, so as to achieve the effect of improving the quality of seismic data in the igneous rock development area. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0051] Figure 1 This is a flowchart of the steps of the design method proposed in one embodiment of the present application;

[0052] Figure 2 This is a schematic diagram of the structure of the drug column proposed in one embodiment of the present application;

[0053] Figure 3 This is a schematic structural diagram of a threaded pipe proposed in one embodiment of the present application;

[0054] Figure 4 It is a structural diagram of a design device proposed in one embodiment of the present application. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0056] In one embodiment, referring to Figure 1 , shows a flowchart of the steps of a method for designing a delayed excitation charge with enhanced downward energy transmission according to an embodiment of the present invention, as shown in FIG. Figure 1 As shown, this design method may specifically include the following steps:

[0057] S101, investigating the surface structure of the work area, obtaining surface structure data, and establishing a surface structure profile; the surface structure data includes the thickness of the igneous rock in the work area, the thickness of the underlying strata of the igneous rock, the velocity profile, and the velocity of the stimulated surrounding rock;

[0058] When conducting surface surveys, micro-logging technology is used. Micro-logging technology can more accurately select the best exciting lithology and well depth for field seismic data acquisition.

[0059] S102, obtaining seismic data and exploration data in the work area, combining them with surface structure data, establishing a velocity model, and performing forward modeling to determine the direction and frequency of the wave field excited by the secondary interference wave in the work area;

[0060] The data obtained from micro-logging are studied using methods such as data processing and interpretation and wave dynamics analysis. Combined with the exploration data, a surface velocity model is established. Based on the velocity model, forward modeling is performed to determine the direction and frequency of the wave field excited by the secondary interference wave in the work area. When designing the charge column, the secondary interference wave can be suppressed by the charge column, which can obtain better quality seismic data.

[0061] S103, based on the surface structure data of the work area, the expected total charge amount and the optimal single-stage charge amount, determining the number of charge column stages and the stage spacing between every two adjacent explosive packages.

[0062] The charge column in this embodiment is composed of multiple explosive bags and multiple threaded tubes. The number of charge column stages refers to the number of stages of the designed multi-stage charge column, and explosive bags are set at both ends of each stage. The level spacing between each adjacent explosive bag is the distance between the explosive bags.

[0063] During excitation, multiple explosive packs distributed on the multi-stage charge column can be excited in sequence to obtain a delayed excitation effect, thereby aggregating the energy generated by the excitation.

[0064] S104, determining a delay time between each two adjacent explosive packages based on the step spacing between each two adjacent explosive packages and the velocity of the excited surrounding rock;

[0065] This embodiment sets the charge column in a multi-stage charge column mode by determining the delay time between each two adjacent explosive packages, so that the charge column can be delayed in excitation. The delayed excitation is to allow the wave field energy excited by different explosive packages to be superimposed and strengthened in the same direction directly below, while the superposition in other directions is weakened, thereby reducing the secondary wave interference generated by the wave field in other directions.

[0066] S105, determining the length of the detonating cord between each two adjacent explosive packs based on the delay time between each two adjacent explosive packs;

[0067] The detonating cord is connected between two adjacent explosive packs. The length of the detonating cord needs to be determined by the delay time. The delay time between two adjacent explosive packs can be controlled by the length of the detonating cord.

[0068] S106, assembling each level of explosive cartridges according to the length of the detonating cord between each two adjacent explosive cartridges and the number of stages and the stage spacing of the explosive cartridges, wherein each two adjacent explosive cartridges are connected by the detonating cord.

[0069] The charge is assembled according to the number of charge levels and the length of the detonating cord to form a multi-stage charge, which has the effect of delayed excitation;

[0070] In this embodiment, the surface structure of the work area is obtained based on the investigation, and the seismic data and exploration data of the work area are combined. Based on the direction and frequency of the wave field excited by the secondary interference wave in the work area, the detonating cord length and delay time of the multi-stage charge are calculated, and the multi-stage charge excitation is designed. The energy generated after the multi-stage charge is excited is directional and can be superimposed and strengthened directly below to effectively weaken the secondary wave interference generated by the excitation and enhance the downward energy, so as to achieve the effect of improving the quality of seismic data in the igneous rock development area.

[0071] In one embodiment, referring to Figure 1 As shown, a flowchart of a method for designing a delayed excitation charge with enhanced down-conducting energy according to an embodiment of the present application is shown. Figure 1 As shown, the following steps are included:

[0072] S101, investigating the surface structure of the work area, obtaining surface structure data, and establishing a surface structure profile; the surface structure data includes the thickness of the igneous rock in the work area, the thickness of the underlying strata of the igneous rock, the velocity profile, and the velocity of the stimulated surrounding rock;

[0073] S102, obtaining seismic data and exploration data in the work area, combining them with surface structure data, establishing a velocity model, and performing forward modeling to determine the direction and frequency of the wave field excited by the secondary interference wave in the work area;

[0074] The seismic data and exploration data of the work area can be obtained from the data accumulated in the previous exploration; by combining with the surface structure data, the established velocity model can reflect the stratigraphic conditions of the work area. Through the forward modeling of the velocity model, the charge column can be designed according to the direction and frequency of the secondary interference wave. The secondary interference wave can be suppressed by the multi-stage delayed excitation charge column, which can obtain higher quality seismic data.

[0075] S103, based on the surface structure data of the work area, the expected total charge amount and the optimal single-stage charge amount, determines the number of charge columns and the distance between each two adjacent explosive packages; comprising the following sub-steps:

[0076] like Figure 2 As shown, Figure 2 The basic structure of a powder column is shown; it includes multiple explosive packs, and two adjacent explosive packs are connected by PVC pipes.

[0077] Figure 3 The structure of the threaded tube used in this embodiment is shown. The PVC tube is a specially made tube made of PVC. Both ends of the threaded tube are provided with threaded structures for connecting to explosive packs. The detonating cord used to detonate two adjacent explosive packs is also wrapped around the threaded tube. The threaded tube can connect two adjacent explosive packs and provide support for them.

[0078] In this embodiment, the explosive packs are prefabricated, so the relevant parameters of the explosive packs, such as the explosive pack detonation velocity, the length of the single-stage explosive pack and the amount of explosive, are all prefabricated and unchanged. During the design, it is only necessary to determine the required number of explosive packs based on the required amount of explosive and the number of stages of the explosive column. If the existing prefabricated explosive packs cannot meet the needs, the required explosive packs can also be obtained through customization.

[0079] When designing the explosive charge dosage, the delayed charge column's high delayed excitation frequency results in rapid energy decay. Therefore, the total charge dosage used in this embodiment is slightly higher than conventional dosages. Furthermore, the charge dosage for each level of explosives must be designed to account for the smallest unit of the formed explosive charge and the dominant excitation frequency of the small explosive charge. Typically, the dominant frequency of the wavelet excited by an explosive charge is high, while high-frequency components in the formation decay rapidly. If the high-frequency attenuation of the target layer exceeds the instrument's dynamic range, the excited high frequencies become wasted, resulting in low total energy.

[0080] Sub-step 1031, when determining the step spacing between every two adjacent explosive packs, it is necessary to first calculate the total delay time of the explosive column.

[0081] Sub-step 1032, determining a total delay time based on the direction of the wave field excited by the secondary interference wave in the work area and the frequency of the secondary wave, includes:

[0082] Based on the frequency of the secondary wave, the period of the secondary wave is obtained by the relationship between the period and the frequency; wherein the relationship between the period and the frequency is as follows:

[0083]

[0084] Where f is the frequency and T is the period.

[0085] After obtaining the frequency of the secondary wave, the size of the period can be calculated using the above formula.

[0086] The total delay time of the drug column is half of the secondary wave period. Once the total delay time of the drug column is determined, the drug column can be designed based on the total delay time.

[0087] The total delay time includes the difference in travel time of seismic waves from the top and bottom of the delayed charge to the ground and the excitation time difference, and the difference in travel time of seismic waves from the top and bottom of the delayed charge to the ground and the excitation time difference are consistent.

[0088] Sub-step 1033, when determining the total length of the charge, it is necessary to base the difference in travel time of the seismic wave from the top and bottom of the delayed charge to the ground and the velocity of the excited surrounding rock.

[0089] Use the following formula:

[0090] L = T1·V1;

[0091] Where L is the total length of the charge; T1 is the difference in travel time of the seismic wave from the top and bottom of the delayed charge to the ground; V1 is the velocity of the excited surrounding rock.

[0092] The total length of the explosive column is the sum of the lengths of the multiple explosive packages plus the sum of the step spacings between two adjacent explosive packages.

[0093] Therefore, when obtaining the stage spacing between two adjacent explosive packages, the length of a single-stage explosive package and the number of explosive column stages should be obtained based on the total length of the explosive column.

[0094] Sub-step 1034, based on the total length of the charge, the number of charge stages, and the length of a single-stage explosive package, the stage spacing between each two adjacent explosive packages is determined using the following formula:

[0095] D = (L - L2·S) / (S-1);

[0096] Where D is the stage spacing; L is the total length of the explosive column; L2 is the length of a single-stage explosive package; and S is the number of explosive column stages.

[0097] The stage spacing is calculated based on the number of stages and the total length of the explosive column, and the threaded pipe with the required length is cut based on the stage spacing between each two adjacent explosive packs.

[0098] S104, determining the delay time between each two adjacent explosive packages based on the step spacing between each two adjacent explosive packages and the velocity rate of the surrounding rock. This includes the following sub-steps:

[0099] Sub-step 1041, based on the total delay time, obtain the excitation time difference; the excitation time difference and the difference in the travel time of the seismic wave from the top and bottom of the delay charge to the ground constitute the total delay time, and the excitation time difference is consistent with the difference in the travel time of the seismic wave from the top and bottom of the delay charge to the ground, so the excitation time difference is half of the total delay time.

[0100] The excitation time difference is the sum of the explosive package detonation time and the detonation cord detonation time, so before calculating the length of the detonating cord, we must first determine the explosive package detonation time.

[0101] Sub-step 1042: Obtain the number of charge columns, the length of a single-stage explosive package, and the explosive package detonation velocity; and determine the explosive package detonation time using the following formula based on the number of charge columns, the length of a single-stage explosive package, and the explosive package detonation velocity:

[0102] T2=(L2·S) / V2;

[0103] Where, T2 is the explosive package detonation time; L2 is the length of a single-stage explosive package; V2 is the explosive package detonation velocity; S is the number of explosive column stages.

[0104] Sub-step 1043, determining the detonation time of the detonating cord based on the excitation time difference and the detonation time of the explosive package;

[0105] The detonation time of the detonating cord is the activation time difference minus the detonation time of the explosive package.

[0106] Sub-step 1044, determining the delay time between each two adjacent explosive charges based on the detonation cord transmission time and the number of explosive charges.

[0107] S105, determining the length of the detonating cord between each two adjacent explosive packs based on the delay time between each two adjacent explosive packs; comprising the following sub-steps:

[0108] Sub-step 1051, obtaining the detonation length of the explosive package and the detonation velocity of the detonating cord;

[0109] Sub-step 1052, determining the basic length of the detonating cord based on the detonation velocity of the detonating cord and the delay time between each two adjacent explosive packs; the basic length of the detonating cord, i.e., the portion of the detonating cord involved in the excitation time difference timing, is obtained by multiplying the detonation velocity of the detonating cord by the delay time.

[0110] Sub-step 1053: determining the length of the detonating cord based on the basic length of the detonating cord and the detonation length of the explosive cartridge.

[0111] The total length of the detonating cord is then calculated by adding the basic length of the detonating cord to the initial length of the explosive charge. The initial length of the explosive charge is the portion of the detonating cord that remains outside the charge column to detonate the explosive charge. The detonation time of this portion of the detonating cord is not included in the total delay time.

[0112] The invention also includes providing a threaded tube, wherein the threaded tube is installed between two adjacent explosive packs, and the detonating cord is wound around the threaded tube;

[0113] The threaded tube is installed between two adjacent explosive packs, can connect the two adjacent explosive packs, and can reduce the detonation time of the detonating cord between the two adjacent explosive packs, so that the detonation velocity of the explosive column matches the velocity of the excited surrounding rock.

[0114] The length of the threaded tube is consistent with the step spacing between each two adjacent explosive packs.

[0115] The speed reduction ratio of the threaded tube is set based on the delay time between each adjacent explosive charge and the step spacing between each adjacent explosive charge. The threaded tube is used to reduce the detonation velocity of the detonating cord between adjacent explosive charges to the same velocity as the surrounding rock. When the detonating cord is wound onto the threaded tube, its diameter increases, and the length of the detonating cord travels longer, affecting the travel time of the explosive charge's excitation energy between adjacent explosive charges. This reduces the detonation velocity of the explosive charge, aligning it with the velocity of the surrounding rock. The speed reduction ratio of the threaded tube is determined by its diameter; a larger diameter increases the speed reduction ratio.

[0116] S106, assembling each level of explosive cartridges according to the length of the detonating cord between each two adjacent explosive cartridges and the number of stages and the stage spacing of the explosive cartridges, wherein each two adjacent explosive cartridges are connected by the detonating cord.

[0117] The explosive columns are set and assembled according to the obtained detonating cord length, number of explosive column stages, length of a single-stage explosive package and the stage spacing between each two adjacent explosive packages.

[0118] When assembling the explosive charge, a threaded tube is installed between two adjacent explosive packs. The outer wall of the threaded tube is threaded, and the detonating cord wrapped around it needs to be embedded in the threads. This allows the threaded tube to slow down the detonating cord and protect it from damage during installation. Once the explosive charge is assembled, it is placed in the designated firing location and fired.

[0119] In this embodiment, the surface structure of the work area is obtained based on the investigation, and the seismic data and exploration data of the work area are combined. Based on the direction and frequency of the wave field excited by the secondary interference wave in the work area, the detonating cord length and delay time of the multi-stage charge are calculated, and the multi-stage charge excitation is designed. The energy generated after the multi-stage charge is excited is directional and can be superimposed and strengthened directly below to effectively weaken the secondary wave interference generated by the excitation and enhance the downward energy, so as to achieve the effect of improving the quality of seismic data in the igneous rock development area.

[0120] In one embodiment, Figure 1 A flowchart of the steps of a method for designing a delayed excitation charge to enhance downward energy transmission is shown.

[0121] In this embodiment, it is taken as an example that the frequency of the interference wave to be suppressed is 50 Hz and the velocity of the excited surrounding rock is 2000 m / s.

[0122] Based on the surface structure data obtained, a three-stage charge was designed, consisting of three explosive cartridges and two sections of threaded pipe, with the two sections connecting two adjacent explosive cartridges. Each section of the explosive cartridge is 0.7m long, with a detonation velocity of 5000m / s. The detonation velocity of the detonating cord connecting the two adjacent explosive cartridges is 7200m / s.

[0123] like Figure 3 As shown, the threaded tube selected in this embodiment is made of PVC with a wall thickness of 1mm and high hardness. The tube has an outer diameter of 6.0cm, a groove depth of 0.4cm, and a pitch of 0.3cm. The detonating cord detonation distance is greater than 3cm. Using a 3.5cm pitch, a 5cm thick threaded tube with a diameter of 6.0cm after wrapping the detonating cord, the diameter becomes the same as the diameter of the explosive. The speed reduction ratio is 3.6, meaning that the apparent velocity of a detonating cord with a detonation velocity of 7200m / s can be reduced to a minimum of 2000m / s after wrapping. By providing a threaded tube, the detonation velocity of the explosive column can be reduced to the velocity of the surrounding rock, thereby maximizing the energy transmitted by the seismic wave.

[0124] According to the interference wave frequency of 50Hz that needs to be suppressed, its period is calculated to be 20ms. Half of 20ms is the total delay time of the charge, which is 10ms. During ground observation, the total delay time includes the excitation time difference and the difference in travel time of the seismic wave from the top and bottom of the delayed charge to the ground. Because the detonation velocity of the charge is consistent with the velocity of the excited surrounding rock, the excitation time difference and the difference in travel time of the seismic wave from the top and bottom of the delayed charge to the ground are also equal, both of which are 5ms.

[0125] The total length of the charge is obtained based on the difference between the velocity of the excited surrounding rock and the travel time of the seismic wave from the top and bottom of the delayed charge to the ground; by using the following formula:

[0126] L = T1·V1;

[0127] Where L is the total length of the charge; T1 is the difference in travel time of the seismic wave from the top and bottom of the delayed charge to the ground; V1 is the velocity of the excited surrounding rock.

[0128] Assuming the travel time difference of the seismic wave from the top and bottom of the delayed charge to the ground is 5 ms and the excited surrounding rock velocity is 2000 m / s, the total length of the charge is obtained to be 10 m.

[0129] The total length of the explosive column includes the total length of the three sections of explosive packs and the total length of the two sections of threaded pipes; among them, the threaded pipes are connected between two adjacent explosive packs, and the length of each section of threaded pipe is the step spacing between each two adjacent explosive packs.

[0130] Based on the total length of the explosive column, the number of stages of the explosive column and the length of a single-stage explosive package, the stage spacing between each two adjacent explosive packages is determined; the following formula can be obtained:

[0131] D = (L - L2·S) / (S-1);

[0132] Where D is the stage spacing; L is the total length of the explosive column; L2 is the length of a single-stage explosive package; and S is the number of explosive column stages.

[0133] Substituting the data into the calculation, we can get that the step spacing between each two adjacent explosive packs = (10-0.7*3) / (3-1);

[0134] The step spacing between each two adjacent explosive packs is 3.95m, and two sections of threaded pipe with a length of 3.95m are cut for use.

[0135] The excitation time difference is 5ms, which is the sum of the explosive package detonation time and the detonation cord detonation time. The explosive package detonation time is calculated based on the length of the single-stage explosive package, the explosive package detonation velocity and the number of explosive column stages using the following formula:

[0136] T2=(L2·S) / V2;

[0137] Where, T2 is the explosive package detonation time; L2 is the length of a single-stage explosive package; V2 is the explosive package detonation velocity; S is the number of explosive column stages.

[0138] Substituting the explosive package length of 0.7m, explosive package detonation velocity of 5000m / s and the charge column number 3, we can obtain that the explosive package detonation time T2 is 0.42ms; then the detonation cord detonation time is 5-0.42=4.58ms.

[0139] Then, based on the detonation velocity of the detonating cord and the delay time between each two adjacent explosive packs, a basic length of the detonating cord is determined;

[0140] The length of the detonating cord is determined based on the basic length of the detonating cord and the detonation length of the explosive cartridge.

[0141] In this embodiment, the detonation length of the explosive pack is 0.7 m, and there are two sections. The delay time between each two adjacent explosive packs is 2.29 ms. Therefore, the length of the detonating cord = 0.7*2 + (2.29*2*7200) / 1000; the length of the detonating cord is 17.9 m. Two sections of detonating cord with a length of 17.9 m are cut for use.

[0142] Regarding the selection of threaded tubes, since they connect between two adjacent explosive charges and are wrapped around the detonating cord, the tubes reduce the detonation velocity of the detonating cord between two adjacent explosive charges to a value consistent with the velocity of the surrounding rock. The speed reduction ratio of the threaded tubes is determined by the delay time between each two adjacent explosive charges and the step spacing between each two adjacent explosive charges.

[0143] In this embodiment, the threaded tube needs to reduce the detonation speed of the detonating cord from 7200 m / s to the excitation speed of the surrounding rock of 2000 m / s, so a threaded tube with a speed reduction ratio of 3.6 should be selected.

[0144] After cutting the corresponding detonating cord and threaded tube, enter the installation process.

[0145] The installation process is as follows:

[0146] First, connect the first explosive pack to the load-bearing rope and fix it, then connect the explosive pack to the threaded pipe and fix the connection. Then one person first puts the detonating cord on the explosive barrel and wraps it with insulating tape, starts to wrap it at the threaded pipe, and wraps it with insulating tape to fix it. While wrapping, go down the well. At the end, make sure that the detonating cord remains 0.7m outside the threaded pipe.

[0147] During the descent, one person pulls the load rope, another holds the threaded pipe upright and securely, and another adds filler to balance buoyancy. When the top of the threaded pipe reaches the wellhead, the second-stage explosive charge is attached. The remaining 0.7m of the third-stage detonating cord is then straightened and attached to the second-stage explosive charge, securing the package.

[0148] When the second explosive charge is lowered into the well, its upper end is connected to the lower end of the second threaded pipe. The second section of detonating cord is wrapped with insulating tape around the second explosive charge. This is then wound around the second threaded pipe and secured with insulating tape. This process continues as the charge is lowered into the well, leaving 0.7m of detonating cord free for connection to the third explosive charge. During the lowering process, one person pulls the load rope, one holds the threaded pipe upright and secures it, and a third adds filler (the number of explosive charges increases, and the procedure is the same as for lowering the second charge).

[0149] The lower end of the third explosive charge was connected to the upper end of the second threaded tube, and an electric detonator was placed in the detonator chamber of the third charge. The detonator connection was strictly carried out in accordance with the "full-process short-circuit charging method." The connection was wrapped with insulating tape, and the anti-floating fork was attached. The charge was lowered down the well using gravity, gently pressed down with the blasting rod when necessary. During the lowering process, one person was responsible for pulling the load rope to prevent the charge from becoming disjointed.

[0150] After the explosive column is in place, use fine sand to seal the well; after the well is sealed, it can be activated.

[0151] In one embodiment, if Figure 4 As shown, a device for designing a delayed excitation charge for enhancing downward energy transmission is provided, comprising:

[0152] The survey module is used to survey the surface structure of the work area, obtain surface structure data, and establish a surface structure profile; the surface structure data includes the thickness of the igneous rock in the work area, the thickness of the underlying strata of the igneous rock, the velocity profile, and the velocity of the stimulated surrounding rock;

[0153] The secondary wave acquisition module is used to obtain seismic data and exploration data in the work area, combine them with surface structure data, establish a velocity model, and perform forward modeling to determine the direction and frequency of the wave field excited by the secondary interference wave in the work area;

[0154] a step spacing determination module, which determines the number of charge columns and the step spacing between each two adjacent explosive packages based on the surface structure data of the work area, the expected total charge amount and the optimal single-stage charge amount;

[0155] a delay time determination module, which determines the delay time between each two adjacent explosive packages according to the step spacing between each two adjacent explosive packages and the velocity of the excited surrounding rock;

[0156] a detonating cord length determination module, which determines the length of the detonating cord between each two adjacent explosive packs based on the delay time between each two adjacent explosive packs;

[0157] The installation module is used to assemble each level of explosive column according to the length of the detonating cord between each adjacent two explosive packets and the number of the explosive column stages and the stage spacing, wherein each adjacent two explosive packets are connected by the detonating cord.

[0158] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0159] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0160] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device that includes the element.

[0161] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for designing a delayed excitation charge with enhanced down-conducting energy, characterized in that: The following steps are involved: Investigate the surface structure of the work area, obtain surface structure data, and establish a surface structure profile; the surface structure data includes the thickness of the igneous rock in the work area, the thickness of the underlying strata of the igneous rock, the velocity profile, and the velocity of the stimulated surrounding rock; Obtain seismic data and exploration data in the work area, combine them with surface structure data, establish a velocity model, and perform forward modeling to determine the direction and frequency of the wave field excited by the secondary interference wave in the work area; Determining the number of charge columns and the distance between each two adjacent explosive packages based on the surface structure data of the work area, the expected total charge amount and the optimal single-stage charge amount; Determining the delay time between each two adjacent explosive packages according to the step spacing between each two adjacent explosive packages and the velocity of the excited surrounding rock; Determine the length of the detonating cord between each two adjacent explosive packs based on the delay time between each two adjacent explosive packs; Assembling the explosive columns of each level according to the length of the detonating cord between each two adjacent explosive packs and the number and spacing of the explosive columns, wherein each two adjacent explosive packs are connected by the detonating cord; The method of determining the number of charge columns and the distance between each two adjacent explosive packages based on the surface structure data of the work area, the expected total charge amount and the optimal single-stage charge amount includes: Determine the total delay time based on the direction of the wave field excited by the secondary interference wave in the work area and the frequency of the secondary wave; the total delay time includes the difference in travel time of the seismic wave from the top and bottom of the delayed charge to the ground; Determining the total length of the charge based on the difference in seismic wave travel time from the top and bottom of the delayed charge to the ground and the velocity of the excited surrounding rock; Determine the number of charge columns and the length of a single-stage explosive package based on the desired total charge and the optimal single-stage charge. The stage spacing between every two adjacent explosive cartridges is determined based on the total length of the explosive column, the number of stages of the explosive column and the length of a single-stage explosive cartridge.

2. The design method according to claim 1, characterized in that: The method of determining the delay time between each two adjacent explosive packs according to the step spacing between each two adjacent explosive packs and the velocity of the excited surrounding rock comprises: Based on the total delay time, obtaining an excitation time difference; Obtaining the number of charge columns, the length of a single-stage explosive package, and the explosive package detonation velocity; determining the explosive package detonation time based on the number of charge columns, the length of a single-stage explosive package, and the explosive package detonation velocity; Determining the detonation time of the detonating cord based on the excitation time difference and the detonation time of the explosive package; The delay time between each two adjacent explosive packs is determined based on the detonation cord transmission time and the number of explosive columns.

3. The design method according to claim 2, characterized in that: The method of determining the length of the detonating cord between each two adjacent explosive packs according to the delay time between each two adjacent explosive packs comprises: Obtaining the detonation length of the explosive package and the detonation velocity of the detonating cord; Determining the basic length of the detonating cord based on the detonation velocity of the detonating cord and the delay time between each two adjacent explosive packs; The length of the detonating cord is determined based on the basic length of the detonating cord and the detonation length of the explosive cartridge.

4. The design method according to claim 1, characterized in that: The determining of the total delay time based on the direction of the wave field excited by the secondary interference wave in the work area and the frequency of the secondary wave comprises: Based on the frequency of the secondary wave, the period of the secondary wave is obtained by using a relationship between period and frequency; The total delay time is half of the secondary wave period.

5. The design method according to claim 1, characterized in that: Determining the total length of the charge based on the difference in seismic wave travel time from the top and bottom of the delayed charge to the ground and the velocity of the excited surrounding rock; Use the following formula: L = T1·V1; Where L is the total length of the charge; T1 is the difference in travel time of the seismic wave from the top and bottom of the delayed charge to the ground; V1 is the velocity of the excited surrounding rock.

6. The design method according to claim 1, characterized in that: The step spacing between each two adjacent explosive packages is determined based on the total length of the explosive column, the number of stages of the explosive column and the length of a single-stage explosive package, using the following formula: D = (L - L2·S) / (S-1); Where D is the stage spacing; L is the total length of the explosive column; L2 is the length of a single-stage explosive package; and S is the number of explosive column stages.

7. The design method according to claim 2, characterized in that: The explosive charge transmission time is determined based on the number of charge columns, the length of a single-stage explosive charge, and the explosive charge detonation velocity using the following formula: T2=(L2·S) / V2; Where, T2 is the explosive package detonation time; L2 is the length of a single-stage explosive package; V2 is the explosive package detonation velocity; S is the number of explosive column stages.

8. The design method according to claim 1, characterized in that: The invention also includes providing a threaded tube, the threaded tube being installed between two adjacent explosive packs, the detonating cord being wound around the threaded tube; the threaded tube being used to reduce the detonation velocity of the detonating cord between the two adjacent explosive packs to the same velocity as the surrounding rock; The length of the threaded tube is consistent with the step spacing between every two adjacent explosive packs; The speed reduction ratio of the threaded tube is set based on the delay time between each two adjacent explosive packs and the step spacing between each two adjacent explosive packs.

9. A device for designing a delayed excitation charge to enhance downward energy transmission, characterized in that: include: Survey module, used to investigate the surface structure of the work area, obtain surface structure data, and establish surface structure profiles; The surface structure data include the thickness of the igneous rock in the work area, the thickness of the underlying strata of the igneous rock, the velocity profile and the velocity of the stimulated surrounding rock; The secondary wave acquisition module is used to obtain seismic data and exploration data in the work area, combine them with surface structure data, establish a velocity model, and perform forward modeling to determine the direction and frequency of the wave field excited by the secondary interference wave in the work area; a step spacing determination module, which determines the number of charge columns and the step spacing between each two adjacent explosive packages based on the surface structure data of the work area, the expected total charge amount and the optimal single-stage charge amount; Determine the total delay time based on the direction of the wave field excited by the secondary interference wave in the work area and the frequency of the secondary wave; the total delay time includes the difference in seismic wave travel time from the top and bottom of the delayed charge column to the ground; determine the total length of the charge column based on the difference in seismic wave travel time from the top and bottom of the delayed charge column to the ground and the excited surrounding rock velocity; determine the number of charge column stages and the length of a single-stage explosive package based on the desired total charge amount and the optimal single-stage charge amount; determine the stage spacing between each two adjacent explosive packages based on the total length of the charge column, the number of charge column stages and the length of a single-stage explosive package; a delay time determination module, which determines the delay time between each two adjacent explosive packages according to the step spacing between each two adjacent explosive packages and the velocity of the excited surrounding rock; a detonating cord length determination module, which determines the length of the detonating cord between each two adjacent explosive packs based on the delay time between each two adjacent explosive packs; The installation module is used to assemble each level of explosive column according to the length of the detonating cord between each adjacent two explosive packets and the number of the explosive column stages and the stage spacing, wherein each adjacent two explosive packets are connected by the detonating cord.

Images