Portable green phase-change energy storage seismic source excitation device system and method

Abstract

The application discloses a portable green phase-change energy storage seismic source exciting device system and method, and belongs to the technical field of seismic exploration; the system comprises a seismic generation subsystem arranged in a seismic source, phase-change energy storage materials are stored in the seismic source, and the seismic generation subsystem has a preset defect; a self-generating heat subsystem is arranged outside the seismic source; the self-generating heat subsystem is communicated with the inside of the seismic generation subsystem through a heat transfer device; wherein the self-generating heat subsystem transmits heat to the inside of the seismic generation subsystem through the heat transfer device, the phase-change energy storage materials absorb the heat to change phase, the pressure in the seismic generation subsystem gradually increases, and explosion occurs when the rated pressure is reached. In the application, the self-generating heat subsystem transmits heat to the inside of the seismic generation subsystem through the heat transfer device, the phase-change energy storage materials absorb the heat to change phase, the pressure in the seismic generation subsystem gradually increases, and explosion occurs when the rated pressure is reached.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of seismic exploration technology, in particular to a portable green phase-change energy storage seismic source excitation device system and method. BACKGROUND

[0002] Using artificial seismic source to excite seismic wave is one of the key ways to realize the detection of regional underground structure, and has been widely used in oil and gas, coalfield and engineering geology, etc. Due to the gradual expansion of human activities, the excitation conditions are becoming more and more demanding, and the concept of environmental protection is deeply rooted in people's hearts. The traditional seismic sources such as explosive source, controlled source, air gun source, hammering source and electric spark source gradually fail to adapt to the requirements of complex surface geological conditions (mountainous area, urban area, marsh, etc.) and environmental protection, etc. At present, new types of portable green seismic sources are widely researched and developed, such as handheld impact seismic source (small electric spark source), backpack seismic source and portable drop hammer seismic source, etc. Although the miniaturization of the seismic source is achieved to some extent, the excitation energy of the seismic source is weak, the detection depth is shallow, and there are many limitations in the scope of application.

[0003] In recent years, the gas explosion source mainly using supercritical carbon dioxide has the advantages of strong explosion energy and green environmental protection, and plays an important role in urban underground space exploration, artificial seismic exploration in coal mine high gas environment and other fields. The explosion process of carbon dioxide source can be directly expressed by the formula: liquid carbon dioxide + heating → gasification expansion ≈ explosion. However, since the carbon dioxide source uses gunpowder as heating medium in the use process, and is initiated by electric current, the initiation process will produce electric spark, which may cause safety hazards, and there are also certain safety hazards in the storage and transportation of supercritical carbon dioxide. In summary, it is of great significance to develop safe, green, portable and efficient seismic source.

[0004] Therefore, it is necessary to provide a portable green phase-change energy storage seismic source excitation device system and method. SUMMARY

[0005] In view of the complex surface geological environment and the demand for green exploration, the present application provides a portable green phase-change energy storage seismic source excitation device system and method, which is used for safe and efficient excitation of field seismic source, and improves the exploration efficiency, so as to solve the problem of safety hazards existing in the excitation process of the existing seismic source.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0007] The seismic generating subsystem is arranged in the interior of the seismic source, and the phase-change energy storage material is stored in the interior of the seismic generating subsystem, and the seismic generating subsystem has a preset defect;

[0008] The self-generating heat subsystem is arranged outside the seismic source, and the self-generating heat subsystem is in communication with the interior of the seismic generating subsystem through the heat transfer device;

[0009] The self-generating heat subsystem transmits heat to the inside of the seismic generating subsystem through the heat transmission device, the phase change energy storage material absorbs heat to change phase, and the pressure inside the seismic generating subsystem gradually increases to explode when reaching the rated pressure.

[0010] Further, the seismic generating subsystem comprises:

[0011] The inner cylindrical shell is used for storing the phase change energy storage material, and the preset defect is located in the middle part of the inner cylindrical shell.

[0012] The outer cylindrical shell is spacedly wrapped outside the inner cylindrical shell, and the outer cylindrical shell is provided with an opening for the heat transmission device to enter.

[0013] Further, the inner cylindrical shell and the outer cylindrical shell both have a specific strength, and the phase change energy storage material is solid-gas type or liquid-gas type.

[0014] Further, the self-generating heat subsystem comprises a cylindrical shell, the cylindrical shell is a water environment, and a self-generating heat system is arranged in the water environment; the self-generating heat subsystem is based on the self-generating heat system to change chemically in the water environment to increase the water temperature.

[0015] Further, the heat transmission device is a water guide pipe.

[0016] Further, the explosion energy is calculated by using the explosion energy formula of the compressible gas and water vapor container, and the formula is

[0017]

[0018] In the formula, E is the explosion energy, V is the internal volume of the container, P1 is the internal pressure of the container, P0 is the external pressure of the container, and K is the adiabatic index of the gas, which represents the ratio of the specific heat at constant pressure to the specific heat at constant volume, and the values of carbon dioxide and ammonia gas are 1.295 and 1.300 respectively.

[0019] Further, the explosion time of a specific seismic source model in different states is obtained by solving the kinetic equation, and the kinetic equation is

[0020]

[0021] In the formula, t is time, α is the percentage of reactant conversion to product, β is the heating rate, A is the pre-exponential factor, Ea is the activation energy, and f(a) is the reaction mechanism function, which is expressed in the form of reaction order in homogeneous reaction. n

[0022] ​Further, the radiation pattern of the seismic source is calculated by a displacement field calculation formula generated by the seismic moment tensor, and the displacement field calculation formula is

[0023]

[0024] In the formula, M ij is the seismic moment tensor, and has two subscripts i and j (both of which take values of 1, 2, and 3, corresponding to forces in x, y, and z directions), and can represent nine different force couple moments, when the subscripts i and j are the same (i.e., M 11 , M 22 , and M 33 ), M ij can be called a vector doublet; u is the displacement generated by the moment tensor source, and u k is the total displacement, and the subscript k takes values of 1, 2, and 3, corresponding to x, y, and z components, respectively, are the displacement of near-field terms, intermediate-field P waves, intermediate-field S waves, far-field P waves, and far-field S waves; r is the distance between the receiving point and the source point; γ is a direction factor; δ is a Dirac function, and the function value is 1 when the two subscript values are equal, and the function value is 0 in other cases; V P is the P wave velocity; V S is the S wave velocity; ρ is the medium density; τ represents a time;

[0025] The expression of each radiation pattern under different vector doublet sources is calculated as

[0026]

[0027] In the formula, u are radiation pattern functions, respectively representing near-field, intermediate-field P waves, intermediate-field S waves, far-field P waves, and far-field S waves generated by M ii .

[0028] A portable green phase change energy storage seismic source excitation method is applied to a portable green phase change energy storage seismic source excitation device system, and the method comprises the following steps:

[0029] S1, device installation

[0030] Shallow wells are drilled in a survey area, a seismic generation subsystem is placed at a suitable depth in the seismic source, and a self-generated heat subsystem is placed on the ground surface;

[0031] S2, chemical self-generated heat and pressurization

[0032] The self-generating heat material is filled into a water environment, and heat is generated in the water environment to rapidly increase the water temperature to a certain temperature, water with the certain temperature is guided into a seismic sub-system through a water guide pipe to heat the phase change energy storage material, the phase change energy storage material absorbs heat to change phase, and the internal pressure of the seismic sub-system gradually increases.

[0033] S3, detonation

[0034] When the internal pressure of the seismic sub-system reaches the maximum pressure that the preset defect can bear, the seismic sub-system breaks, thereby generating an earthquake signal.

[0035] The present application has the following beneficial effects:

[0036] 1. In the present application, the self-generating heat sub-system transmits heat to the interior of the seismic sub-system through a heat transmission device, the phase change energy storage material absorbs heat to change phase, the internal pressure of the seismic sub-system gradually increases, and explosion occurs when the rated pressure is reached.

[0037] 2. In the present application, the excitation process of the phase change energy storage material only relies on physical and chemical changes, does not need electric excitation, does not pollute the environment, does not involve dangerous environments such as high-voltage electricity, the operation process is safe and efficient, the explosion process is green, safe and efficient, belongs to the category of gas explosion sources, has strong energy release, large detection depth, and has great application prospect and scientific research value.

[0038] 3. Unlike traditional seismic sources (explosive seismic source, controllable seismic source, air gun seismic source, electric spark seismic source, drop hammer seismic source, etc.), the present application uses solid-gas type or liquid-gas type phase change energy storage material, self-generating heat material, high-strength metal or non-metal shell (aluminum alloy) and other related industrial basic materials, which are low in price, safe and environmentally friendly.

[0039] 4. The present application produces a modern exploration seismic source device system that meets the green development through a simple material combination method, and has the advantages of small size, portability, strong environmental adaptability, simple production and manufacturing process, low cost and strong implementation feasibility. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 It is a schematic diagram of the seismic source device in the present application. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0042] The present application uses phase change energy storage material and a chemical self-generating heat system to propose a portable green phase change energy storage seismic source device system and method based on a gas explosion seismic source, which is used for safe and efficient excitation of field seismic sources and improves exploration efficiency. Figure 1A portable green phase-change energy storage seismic source excitation device system comprises:

[0043] (1) Seismic source internal seismic generation subsystem

[0044] The seismic generation subsystem inside the seismic source is used to store phase-change energy storage materials, and the seismic generation subsystem has a preset defect. The seismic generation subsystem comprises: an inner cylindrical shell for storing phase-change energy storage materials; the preset defect is located in the middle of the inner cylindrical shell. An outer cylindrical shell is spaced apart and wrapped outside the inner cylindrical shell, and an opening is formed on the outer cylindrical shell for the heat transfer device to enter, for safety protection and continuous heat preservation of the entire seismic generation subsystem. The inner cylindrical shell and the outer cylindrical shell are both made of high-strength materials, and the phase-change energy storage material is solid-gas or liquid-gas.

[0045] Specifically, the phase-change energy storage material is the basic material for causing explosion, which realizes phase state change by absorbing external heat, generates a large amount of gas, and gradually forms an internal high-pressure state in the seismic generation subsystem. There is a certain defect in the middle of the seismic generation subsystem, and the breaking strength at the defect is relatively low, so when the internal pressure reaches the maximum pressure that the defect can withstand, the seismic generation subsystem will instantaneously break to both ends, that is, a pair of force sources F is generated.

[0046] In the embodiment of the present application, ammonium bicarbonate of solid-gas type is taken as an example of the phase-change energy storage material inside the seismic source. The main reason is that the material has low phase change temperature (58℃) and high phase change latent heat (3430J / g), and the product after phase change is carbon dioxide, ammonia and water. The material is low in price and meets the requirements of safety, greenness and environmental protection. The explosion energy and explosion time of the seismic source are the key parameters of the seismic generation system. Through the explosion energy calculation principle of the gas explosion seismic source and the thermal decomposition reaction kinetics equation, the theoretical calculation formula of the two is obtained, which is as follows:

[0047] Explosion energy: The phase-change energy storage seismic source essentially belongs to a gas explosion seismic source, and the principle of the explosion process is similar to that of the compressed gas and water vapor container explosion. Therefore, the compressed gas and water vapor container explosion energy formula can be used to calculate the explosion energy, as shown in formula (1).

[0048]

[0049] In the formula, E is the explosion energy; V is the internal volume of the container; P1 is the internal pressure of the container; P0 is the external pressure of the container; K is the adiabatic index of the gas, which represents the ratio of the specific heat at constant pressure to the specific heat at constant volume, and the values of carbon dioxide and ammonia are 1.295 and 1.300 respectively.

[0050] Assuming that the initial temperature of the phase change energy storage seismic source based on ammonium bicarbonate material is 15℃, the initial pressure is one standard atmosphere, the seismic source system is heated by the self-heat subsystem and maintained at 90℃, the thermal decomposition conversion efficiency of ammonium bicarbonate is 100%, and the maximum pressure that can be borne by the defect of the shell material of the seismic system is equal to the maximum pressure formed by the system, the explosion energy and the TNT equivalent of the seismic source of different specifications are calculated theoretically by using the actual gas state equation (R-K gas state equation proposed by Redlich and Kwong) and the energy calculation formula of the gas explosion seismic source, and the results are shown in Table 1.

[0051] Table 1 Comparison of the property characteristics of the phase change energy storage seismic source

[0052]

[0053]

[0054] In the calculation process, the phase change of water and the influence of the reaction with water and ammonia are not considered, and the related parameters of carbon dioxide and ammonia are taken as the average values (such as the adiabatic index K). The data show that the phase change energy storage seismic source can realize small-scale and strong-energy explosion, and nearly 60MPa of internal high pressure and nearly 30kJ of explosion energy can be formed in a columnar seismic source model with a diameter of 5cm, a height of 10cm and a mass of ammonium bicarbonate of 237g. The explosion energy of the seismic source is related to the specification parameters of the seismic source and the pressure resistance of the defect of the shell of the seismic system. Increasing the specification of the seismic source and improving the pressure resistance of the defect of the shell can increase the explosion energy, but blindly increasing the specification of the seismic source will greatly reduce the phase change conversion efficiency, leading to a too long seismic excitation time or difficulty in normally exciting the seismic source. The mass of ammonium bicarbonate, the phase change conversion efficiency and other factors will also directly affect the size of the internal pressure formed in the phase change process.

[0055] Explosion time: The explosion time is closely related to the phase change efficiency of the phase change energy storage material, and in the seismic source model proposed in the present example, it can be understood as the time required for the thermal decomposition of ammonium bicarbonate to a certain value. The explosion time of the seismic source is related to the environment. In a heterogeneous system under isothermal and non-isothermal conditions, the thermal decomposition reaction of ammonium bicarbonate satisfies the kinetic equations (2) and (3), respectively. The explosion time of a specific seismic source model under different conditions can be obtained by solving the kinetic equation.

[0056]

[0057] In the formula, t is time; α is the percentage of the conversion of reactants to products; β is the heating rate, β=dT / dt; A is the pre-exponential factor, Ea is the activation energy; f(a) is the reaction mechanism function, which is generally expressed in the form of reaction order f(a)=(1-α) n in homogeneous reactions.

[0058] In addition, the radiation pattern of the source can reflect the displacement variation with the observation point position when the earthquake occurs at the same time, therefore, it is necessary to analyze the radiation pattern of the source in depth. Aki and Richard (2002) proposed a displacement field calculation formula generated by the seismic moment tensor, as shown in formula (4). The displacement field contains near-field, intermediate field and far-field. According to the formula, it can be found that the time function of the near-field, intermediate field or far-field is controlled by the directional factor, that is, each term has a specific radiation pattern.

[0059]

[0060] In the formula, M ij is the seismic moment tensor, and has two subscripts i and j (both of which are 1, 2, 3, corresponding to the forces in the x, y and z directions), which can represent 9 different force couple moments. When the subscripts i and j are the same (i.e. M 11 , M 22 , M 33 ), M ij can be called a vector dipole; u is the displacement generated by the moment tensor source, and u k is the total displacement, and subscript k takes values 1, 2, 3, corresponding to the x, y and z components, are the displacements of the near-field term, the intermediate field P wave, the intermediate field S wave, the far-field P wave and the far-field S wave respectively; r is the distance between the receiving point and the source point; γ is the directional factor; δ is the Dirac function, which is 1 when the two subscript values are equal, and 0 in other cases; V P is the longitudinal wave velocity; V S is the transverse wave velocity; ρ is the medium density; τ represents a time.

[0061] The phase change energy storage source can have various forms. Taking the columnar phase change energy storage source designed in the application as an example, since it can generate a pair of forces with equal size and opposite direction, it is simplified as a vector dipole source. The expression of each radiation pattern under different vector dipole sources can be calculated from formula (4) as formulas (5)-(9).

[0062]

[0063] In the formula, u are the radiation pattern functions, respectively representing the near-field, the intermediate field P wave, the intermediate field S wave, the far-field P wave and the far-field S wave generated by M ii .

[0064] (2) External self-generating heat subsystem of the source

[0065] The self-generating heat subsystem is in communication with the interior of the seismic generating subsystem through a heat transfer device, wherein the heat transfer device is preferably a water guide pipe. The self-generating heat subsystem comprises a columnar shell, and a water environment is arranged in the columnar shell, and a self-generating heat system is arranged in the water environment.

[0066] Specifically, the self-generating heat subsystem is a heat source of the whole system, and the main principle is that different chemical materials are mixed in the water environment, a large amount of heat is generated through chemical change, and the heat is transmitted to the seismic generating subsystem in the interior of the seismic source.

[0067] It can be understood that the self-generating heat subsystem in the application transmits heat to the interior of the seismic generating subsystem through the heat transfer device, the phase change energy storage material absorbs heat to change the phase state, and the internal pressure of the seismic generating subsystem gradually increases to explode when the rated pressure is reached.

[0068] The self-generating heat subsystem outside the seismic source is based on the chemical change of the self-generating heat system in the water environment, and transmits sufficient heat to the seismic generating system in the interior of the seismic source to ensure that the seismic source can be effectively excited. Considering the influence of the size of the seismic source and the excitation efficiency, the system needs to have the characteristics of fast temperature rising rate and high energy efficiency. The self-generating heat system has many types, and common types include a calcium oxide heat generating system, a nitrite and ammonium salt heat generating system, a nitrite and urea heat generating system, a hydrogen peroxide heat generating system, and a polyhydroxy aldehyde heat generating system. In addition, a heating bag mainly composed of calcium oxide, aluminum powder and sodium carbonate has excellent heating performance and is commonly used for food heating and can be used as a scheme for constructing the self-generating heat system. The shell of the self-generating heat system is used for storing the self-generating heat material and heat preservation of the whole self-generating heat subsystem, and has excellent heat resistance and thermal insulation.

[0069] In the application, the excitation process of the phase change energy storage material only relies on physical and chemical changes, does not need electric excitation, does not pollute the environment, does not involve dangerous environments such as high-voltage electricity, the operation process is safe and efficient, the explosion process is green, safe and efficient, belongs to the category of gas explosion seismic sources, has strong energy release, large detection depth, and has great application prospect and scientific research value.

[0070] Unlike traditional seismic sources (explosive seismic sources, controllable seismic sources, air gun seismic sources, electric spark seismic sources, drop hammer seismic sources, etc.), the application uses solid-gas type or liquid-gas type phase change energy storage materials, self-generating heat materials, high-strength metal or non-metal shells (aluminum alloy) and other related industrial basic materials, which are low in price, safe and environmentally friendly.

[0071] The application produces a modern exploration seismic source device system meeting green development by adopting a simple material combination mode, and has the advantages of small size, portability, strong environmental adaptability, simple production and manufacturing process, low cost and strong implementation feasibility.

[0072] A portable green phase change energy storage seismic source excitation method is applied to a portable green phase change energy storage seismic source excitation device system, and the method comprises the following steps:

[0073] S1, device installation

[0074] A shallow well is drilled in a survey area, a seismic subsystem is placed at a suitable depth in the seismic source, and a self-heating subsystem is placed on the ground surface.

[0075] S2, chemical self-heating and pressurization

[0076] The self-heating material is filled into the water environment, heat is generated in the water environment, the water temperature is rapidly increased to a high temperature state, the high-temperature water is introduced into the seismic subsystem through the water guide pipe to heat the phase change energy storage material, the phase change energy storage material absorbs heat and changes phase, and the internal pressure of the seismic subsystem is gradually increased.

[0077] S3, detonation

[0078] After the internal pressure of the seismic subsystem is pressurized for a period of time, when the internal pressure of the seismic subsystem reaches the maximum pressure that the preset defect can withstand, the seismic subsystem breaks, a pair of force sources F are generated, and a seismic signal is generated.

[0079] The above-described embodiments only describe the preferred modes of the application and do not limit the scope of the application. Without departing from the design spirit of the application, various modifications and improvements to the technical solutions of the application made by those skilled in the art shall fall within the protection scope of the claims of the application.

Claims

1. A portable green phase-change energy storage seismic source activation device, characterized in that, The portable green phase-change energy seismic source excitation device comprises a seismic source and a self-generating heat system. The self-generating heat system is in communication with the inside of the seismic source through a heat transfer device. The self-generating heat system transmits heat to the inside of the seismic source through the heat transfer device, and the phase-change energy storage material absorbs the heat to change the phase, so that the internal pressure of the seismic source gradually increases and explodes when the rated pressure is reached. The seismic source comprises an inner cylindrical shell for storing the phase-change energy storage material, and a preset defect is located in the middle of the inner cylindrical shell. An outer cylindrical shell is spacedly wrapped outside the inner cylindrical shell, and an opening for the heat transfer device to enter is formed on the outer cylindrical shell. The self-generating heat system comprises a cylindrical shell, a water environment in the cylindrical shell, and a self-generating heat system arranged in the water environment. The inner cylindrical shell and the outer cylindrical shell have a specific strength, and the phase-change energy storage material is solid-gas or liquid-gas. The heat transfer device is a water guide pipe.

2. The portable green phase-change energy storage seismic source activation device of claim 1, wherein, The explosion energy can be calculated by using the formula of the explosion energy of a container filled with compressed gas and water vapor.

3. The portable green phase-change energy storage seismic source activation device of claim 1, wherein, In the formula, E is the explosion energy, V is the internal volume of the container, P1 is the internal pressure of the container, P0 is the external pressure of the container, and K is the adiabatic index of the gas, which represents the ratio of the specific heat at constant pressure to the specific heat at constant volume, and the values of carbon dioxide and ammonia gas are 1.295 and 1.300, respectively.

4. The portable green phase-change energy storage seismic source activation device of claim 1, wherein, The explosion time of a specific seismic source model under different states is obtained by solving the kinetic equation. ， The seismic source radiation pattern is calculated by the displacement field calculation formula of the seismic moment tensor.

5. The portable green phase-change energy storage seismic source activation device of claim 4, wherein, The expression of each radiation pattern under different vector dipole sources is calculated. ， where t is time; a is the percent conversion of reactants to products; β is the heating rate, where β = dT / dt; A is the pre-exponential factor, Ea is the activation energy; and f(a) is a reaction mechanism function, which in the case of a homogeneous reaction is expressed in the form of a reaction order, f(a) = (1 - a) n where R is the gas constant and T is temperature. g where t is time; a is the percent conversion of reactants to products; β is the heating rate, where β = dT / dt; A is the pre-exponential factor, Ea is the activation energy; and f(a) is a reaction mechanism function, which in the case of a homogeneous reaction is expressed in the form of a reaction order, f(a) = (1 - a) n where R is the gas constant and T is temperature. < 6. The portable green phase-change energy storage seismic source activation device of claim 5, wherein, The method is applied to the portable green phase-change energy seismic source excitation device of any one of claims 1-6. ， where M ij is the seismic moment tensor, with two indices i and j, both ranging from 1 to 3, corresponding to the x, y, z directions, and can represent 9 different force couples, when i and j are the same, i.e. M 11 , M 22 , M 33 , M ij are called vector double-couple; u is the displacement produced by the moment tensor source, u k is the total displacement, with index k ranging from 1 to 3, corresponding to the x, y, z components, , , , , are the near-field term, the mid-field P-wave term, the mid-field S-wave term, the far-field P-wave term, and the far-field S-wave term, respectively; r is the distance between the receiver and the source; γ is the directional factor; δ is the Dirac function, with value 1 when the two indices are the same, and 0 otherwise; V P is the P-wave velocity; V S is the S-wave velocity; ρ is the medium density; τ represents a time; γ i represents the cosine of the angle between the ray direction and the x-axis, γ k represents the cosine of the angle between the ray direction and the y-axis, γ j represents the cosine of the angle between the ray direction and the z-axis, and δ is the Dirac function, where δ ij represents 1 when the coordinate directions i and j are the same, and 0 otherwise; δ ki represents 1 when the coordinate directions k and i are the same, and 0 otherwise; δ kj represents 1 when the coordinate directions k and j are the same, and 0 otherwise. S1, device installation ， wherein , , , , are radiation pattern functions representing the near field, the intermediate field P-wave, the intermediate field S-wave, the far field P-wave and the far field S-wave, respectively, generated by M ii .

7. A method of portable green phase-change energy storage seismic source activation, characterized by, S2, chemical self-generating heat and pressurization S3, detonation When the internal pressure of the seismic source reaches the maximum pressure that the preset defect can withstand, the seismic source breaks, thereby generating a seismic signal. ​ ​ ​ ​

Images