Method and device for evaluating underground coal gasification selected area

Abstract

The invention provides a method and device for evaluating a coal underground gasification selected area, and belongs to the technical field of coal underground gasification. The method comprises the steps that the thickness value and coal volatile components of an underground coal seam in the coal underground gasification selected area to be evaluated are obtained; calculating the product of the thickness value and the coal volatile component to obtain an evaluation index; under the condition that the evaluation index is greater than or equal to a third threshold value, the evaluation result of the to-be-evaluated coal underground gasification selection area is suitable for carrying out coal underground gasification; under the condition that the evaluation index is smaller than a third threshold value, the evaluation result of the to-be-evaluated coal underground gasification selected area is not suitable for coal underground gasification. The device comprises a data acquisition module, a product calculation module and an evaluation result output module. The method is simple and convenient to use, small in calculation amount and easy to understand and memorize.

Description

Technical Field

[0001] The present application belongs to the technical field of underground coal gasification, and in particular, relates to a method and device for evaluating underground coal gasification area selection. Background Art

[0002] Underground Coal Gasification (UCG) is an engineering process that uses controlled combustion of coal in coal-bearing strata underground to produce combustible synthesis gas such as methane, hydrogen, and carbon monoxide under the thermal and chemical effects of coal.

[0003] Geological evaluation and site selection are the key to the implementation of UCG. They are crucial to the construction and stable operation of the gasifier and determine whether the gasifier can safely, long-term and stably produce qualified raw coal gas. In the existing technology, based on the experience of shallow UCG field tests and indoor research results, the optimization criteria for UCG favorable areas have been proposed, including some evaluation systems and indicators. In addition, in order to avoid the risks of gas escape, groundwater pollution, surface subsidence, etc., and to make the gasification process stable and economical, the basic principles of geological evaluation are proposed from multiple perspectives such as coal reserves, coal seam conditions, and geological structures. The appropriate values ​​of indicators such as coal seam thickness, inclination, water content, gangue content, distance from faults, roof and floor permeability, and gas permeability are pointed out in detail, and the basic methods and requirements for modern UCG site selection decisions are pointed out. With the development of underground coal gasification technology, geological evaluation standards have gradually transitioned from qualitative to quantitative. In order to clarify the geological factors affecting underground coal gasification, some area evaluation methods and models construct a large and complex geological indicator evaluation system, which mainly includes seven categories: coal rock and coal quality conditions, coal seam occurrence conditions, surrounding rock conditions, geological structure conditions, hydrogeological conditions, environmental geological conditions and other conditions.

[0004] In summary, the underground coal gasification zone selection evaluation process in the prior art usually requires obtaining a large number of parameters, and the calculation process is also quite complicated, so it is inconvenient to use. Summary of the invention

[0005] Based on the above technical problems, the present application proposes a method and device for evaluating underground coal gasification zones, which uses very few input parameters and can also obtain relatively accurate underground coal gasification zone evaluation results.

[0006] In the first aspect, the present application proposes a method for evaluating underground coal gasification area selection, comprising:

[0007] Obtain the thickness of underground coal seams and coal volatiles in the underground coal gasification area to be evaluated;

[0008] Calculate the product of the thickness value and the volatile matter of the coal to obtain the evaluation index;

[0009] When the evaluation index is greater than or equal to the third threshold, the evaluation result of the underground coal gasification area to be evaluated is suitable for carrying out underground coal gasification;

[0010] When the evaluation index is less than the third threshold value, the result of the evaluation of the underground coal gasification area to be evaluated is that it is not suitable for carrying out underground coal gasification.

[0011] The method for evaluating underground coal gasification area selection further includes:

[0012] Select the underground coal gasification area to be evaluated;

[0013] The selection principle of the underground coal gasification area to be evaluated is: select the underground coal gasification area whose coal resource volume is greater than a first threshold and the coal seam roof lithology density is greater than a second threshold as the underground coal gasification area to be evaluated.

[0014] The thickness value is multiple, and the coal volatilization is multiple;

[0015] The product of the calculated thickness value and the volatile matter of the coal is used to obtain an evaluation index, including:

[0016] Calculate a first average value of the plurality of thickness values ​​and a second average value of the plurality of coal volatiles;

[0017] The product of the first average value and the second average value is calculated to obtain an evaluation index.

[0018] The method for evaluating underground coal gasification area selection further includes:

[0019] When the evaluation result shows that there are multiple underground coal gasification areas to be evaluated that are suitable for carrying out underground coal gasification, the corresponding multiple evaluation indexes are sorted from large to small;

[0020] The underground coal gasification selection areas corresponding to the first M evaluation indexes are selected from the ranking as the underground coal gasification selection areas that are ultimately suitable for carrying out underground coal gasification.

[0021] The volatile content of coal refers to the yield of volatile organic matter after coal is heated in an airtight state under specified conditions.

[0022] The coal volatile matter is the dry ash-free volatile matter of coal.

[0023] The thickness value ranges from [1.5m to 15m].

[0024] In a second aspect, the present application proposes a device for evaluating underground coal gasification selection, comprising:

[0025] A data acquisition module is used to obtain the thickness of underground coal seams and coal volatiles in the underground coal gasification area to be evaluated;

[0026] The product calculation module is used to calculate the product of the thickness value and the volatile matter of the coal to obtain the evaluation index;

[0027] An evaluation result output module is used to, when the evaluation index is greater than or equal to a third threshold, determine that the evaluation result of the underground coal gasification selection area to be evaluated is suitable for carrying out underground coal gasification; when the evaluation index is less than the third threshold, determine that the evaluation result of the underground coal gasification selection area to be evaluated is not suitable for carrying out underground coal gasification.

[0028] In a third aspect, the present application proposes an electronic device, comprising: a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the method for evaluating underground coal gasification selection is executed.

[0029] In a fourth aspect, the present application proposes a computer-readable storage medium storing executable instructions, which, when executed, enable a processor to execute the method for evaluating underground coal gasification zones.

[0030] Beneficial effects:

[0031] The present application proposes a method and device for evaluating underground coal gasification zones. The present application uses two most basic and critical geological parameters, including: the thickness of the coal seam and the volatile matter of the coal, and utilizes the product of the two as a rapid evaluation index. It can not only conduct a preliminary rapid evaluation of the underground coal gasification zones, but also quantitatively rank the zones. The application has the characteristics of being simple, convenient, and easy to understand and remember. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a flow chart of the method for evaluating underground coal gasification area selection in Example 1 of the present application;

[0033] Figure 2 This is a rapid evaluation index diagram of underground coal gasification selection area according to an embodiment of the present application;

[0034] Figure 3 This is a flow chart of the method for evaluating underground coal gasification area selection in Example 2 of the present application;

[0035] Figure 4 This is a flow chart of the method for evaluating underground coal gasification area selection in Example 3 of the present application;

[0036] Figure 5 This is a principle block diagram of the device for evaluating underground coal gasification zone selection in Example 3 of the present application. DETAILED DESCRIPTION

[0037] The present disclosure is further described below in conjunction with the embodiments shown in the accompanying drawings.

[0038] Geological evaluation and site selection are the key to the implementation of UCG. They are crucial to the construction and stable operation of the gasifier and determine whether the gasifier can safely, long-term and stably produce qualified raw coal gas. Based on the experience of shallow UCG field tests and indoor research results, many scholars have proposed the optimization criteria for UCG favorable areas. In recent years, some scholars have gradually proposed some evaluation systems and indicators. In order to avoid the risks of gas escape, groundwater pollution, surface subsidence, and make the gasification process stable and economical, some scholars have proposed the basic principles of geological evaluation from multiple perspectives such as coal reserves, coal seam conditions, and geological structures. They have pointed out in detail the appropriate values ​​of indicators such as coal seam thickness, inclination, water content, gangue content, distance from faults, roof and floor permeability, and gas permeability. At the same time, they have pointed out the basic methods and requirements for modern UCG site selection decisions. With the development of underground coal gasification technology, geological evaluation standards have gradually transitioned from qualitative to quantitative. In the prior art, a hierarchical model for evaluating coal seam resource conditions has been constructed, and the weight coefficients of the evaluation indicators are ranked as follows: coal rock and coal quality > hydrogeology > coal seam occurrence > geological structure, and the feasibility of the main mining coal seam in the Ningzheng mining area has been evaluated. Some other researchers have used the secondary fuzzy comprehensive evaluation method to construct a drilling underground gasification geological evaluation model, calculated the score value of the adaptability of coal seam underground gasification, and pointed out that the comprehensive score of the No. 5 coal seam in the Jinghai coal-bearing area of ​​Tianjin belongs to the underground gasification suitable area. Other researchers have established a multi-level fuzzy mathematical evaluation model, which can be used to calculate the underground coal gasification index Ai. Class I favorable areas are the key areas of UCG. These selection evaluation methods and models are to clarify the geological factors affecting underground coal gasification. By constructing a large number of complex geological indicator evaluation systems, they mainly include seven categories: coal rock and coal quality conditions, coal seam occurrence conditions, surrounding rock conditions, geological structure conditions, hydrogeological conditions, environmental geological conditions and other conditions. A lot of parameters need to be obtained during the evaluation process, and the calculation process is also quite complicated, so it is very inconvenient to use.

[0039] In order to simply, conveniently and accurately evaluate the coal resource conditions in the underground coal gasification zone, the present application provides a method and device for evaluating underground coal gasification zones. When the coal resources are large and the rock properties of the coal seam roof are dense, the two most basic coal geological resource parameters are used to conduct zone evaluation research. Without considering the engineering geological conditions, it is possible to quickly evaluate whether the underground coal seams in certain blocks meet the basic conditions for underground coal gasification, and conduct preliminary zone selection.

[0040] Embodiment 1:

[0041] This embodiment proposes a method for evaluating underground coal gasification area selection, such as Figure 1 As shown, including:

[0042] Step S1: Obtain the thickness value of the underground coal seam and the volatile matter of the coal in the underground coal gasification selection area to be evaluated;

[0043] In this embodiment, two parameters, namely, the thickness of the coal seam and the volatile matter of the coal, which are of decisive significance to the quality of the coal seam resources for underground coal gasification, are selected for evaluation.

[0044] The thickness of the coal seam directly affects the gasification calorific value and gasification efficiency, and is abbreviated as H. Considering that when the thickness of the coal seam is less than 1.5m, the cooling effect of the top and bottom plates of the coal seam will lead to poor underground gasification thermal efficiency and a decrease in the calorific value of the coal gas, this embodiment believes that the thickness range of the coal seam that is more suitable for underground coal gasification is [1.5m~15m].

[0045] Volatile matter is the combustible gas produced by the thermal decomposition of organic matter in coal under certain temperature and conditions, and is abbreviated as V. The yield of volatile organic matter after coal is heated in an airtight state under specified conditions is called volatile matter. In fact, the volatile matter produced by coal under such conditions includes the gaseous products of pyrolysis of organic matter in coal, as well as water vapor produced by water in coal and CO2 decomposed by carbonate minerals. Volatile matter is part of coal volatile matter, but it is not equivalent to volatile matter. In addition, volatile matter is not an inherent substance in coal, but a thermal decomposition product of coal under a specific heating system. It is a mixed gas composed of various hydrocarbons, hydrogen, carbon monoxide and other compounds, which is consistent with the combustible gas produced after underground coal gasification. Therefore, the amount of volatile matter is a key resource indicator of underground coal gasification. Volatile matter is also the main indicator for classifying coal, and is used to preliminarily determine the processing and utilization properties of coal. The yield of volatile matter in coal is closely related to the degree of coalification. The lower the degree of coalification, the higher the volatile matter. As the degree of coalification deepens, the volatile matter gradually decreases. According to my country's coal quality index classification standards, volatile matter can be divided into 6 levels, as shown in Table 1.

[0046] Table 1 Classification standards of coal volatile matter

[0047] Level Name Code Volatile matter on dry ash-free basis (Vdaf) range / % Extra low volatile coal SLV ≤10.00 Low volatile coal LV >10.00～20.00 Medium volatile coal MV >20.00～28.00 Medium to high volatile coal MHV >28.00～37.00 High volatile coal HV >37.00～50.00 Extra high volatile coal HA >50.00

[0048] As can be seen from Table 1, the coal volatile matter is the dry ash-free volatile matter of the coal.

[0049] Step S2: Calculate the product of the thickness value and the volatile matter of the coal to obtain an evaluation index;

[0050] In this embodiment, the thickness value (H) of the coal seam and the value of the volatile matter (V) of the coal are multiplied, and the product H×V is used as a rapid evaluation index of underground coal gasification.

[0051] Step S3: When the evaluation index is greater than or equal to the third threshold, the evaluation result of the underground coal gasification area to be evaluated is suitable for underground coal gasification; when the evaluation index is less than the third threshold, the evaluation result of the underground coal gasification area to be evaluated is not suitable for underground coal gasification.

[0052] In this embodiment, since the product of the lower limit of the more suitable coal seam gasification thickness of 1.5m and the limit value of the highest volatile matter of coal of 100%; the product of the upper limit of the more suitable coal seam gasification thickness of 15m and the value of the low volatile matter of coal of 10%, both are 1.5, H×V=1.5 is used as the rapid evaluation index of underground coal gasification, so the third threshold value can be set to 1.5. When the product of the thickness value (H) of the coal seam and the volatile matter (V) of the block is ≥1.5, it means that the evaluation result of the underground coal gasification area to be evaluated is suitable for carrying out underground coal gasification; when the product of the thickness (H) of the coal seam and the volatile matter (V) is <1.5, it means that the evaluation result of the underground coal gasification area to be evaluated is suitable for carrying out underground coal gasification. Figure 2 shown.

[0053] The method for evaluating the underground coal gasification area of ​​this embodiment only uses two parameters, namely, the thickness value of the underground coal seam in the underground coal gasification area to be evaluated and the coal volatile matter; the evaluation index is obtained by multiplying the thickness value and the coal volatile matter; when the evaluation index is greater than or equal to the third threshold value, the evaluation result of the underground coal gasification area to be evaluated is suitable for carrying out underground coal gasification; when the evaluation index is less than the third threshold value, the evaluation result of the underground coal gasification area to be evaluated is not suitable for carrying out underground coal gasification. This embodiment only uses the product of two parameters to obtain the evaluation index, and can perform a preliminary and rapid evaluation of the underground coal gasification area based on the evaluation index. The method of this embodiment is simple and convenient to use, has a small amount of calculation, and is easy to understand and remember.

[0054] Embodiment 2:

[0055] The method for evaluating underground coal gasification area selection in this embodiment is as follows: Figure 3 As shown, including:

[0056] Step S101: Selecting an underground coal gasification area to be evaluated;

[0057] In this embodiment, the selection principle of the underground coal gasification area to be evaluated is: select the underground coal gasification area where the coal resource amount is greater than the first threshold and the coal seam roof lithology density is greater than the second threshold as the underground coal gasification area to be evaluated. That is to say, in this embodiment, only when the coal resource amount in a certain area is large and the coal seam roof lithology is dense, will the area be considered as the underground coal gasification area to be evaluated.

[0058] Step S102: Obtain the thickness value of the underground coal seam and the volatile matter of the coal in the underground coal gasification selection area to be evaluated;

[0059] In this embodiment, the volatile content of coal refers to the yield of volatile organic matter after the coal is heated in an airtight state under specified conditions.

[0060] The coal volatile matter is the dry ash-free volatile matter of coal.

[0061] The thickness value ranges from [1.5m to 15m].

[0062] Step S103: Calculate the product of the thickness value and the volatile matter of the coal to obtain an evaluation index;

[0063] In actual situations, the thickness of a coal seam may have multiple different collected values ​​depending on the collection location. Similarly, there may be multiple coal volatiles collected at different locations. Therefore, to obtain an evaluation index, it is necessary to first take the average values ​​of the thickness value and the coal volatiles, respectively, and finally take the product of the two average values ​​as the evaluation index.

[0064] The product of the calculated thickness value and the volatile matter of the coal is used to obtain an evaluation index, including:

[0065] Calculate a first average value of the plurality of thickness values ​​and a second average value of the plurality of coal volatiles;

[0066] The product of the first average value and the second average value is calculated to obtain an evaluation index.

[0067] Step S104: When the evaluation index is greater than or equal to the third threshold, the evaluation result of the underground coal gasification area to be evaluated is suitable for carrying out underground coal gasification; when the evaluation index is less than the third threshold, the evaluation result of the underground coal gasification area to be evaluated is not suitable for carrying out underground coal gasification.

[0068] The method for evaluating the underground coal gasification area proposed in this embodiment first needs to select the underground coal gasification area to be evaluated. When the coal resources are large and the lithology of the coal seam roof is dense, the product of the thickness value and the coal volatile matter is calculated to obtain the evaluation index. When there are multiple values ​​for both the thickness value and the coal volatile matter, the first average value of the multiple thickness values ​​and the second average value of the multiple coal volatile matter are calculated; the product of the first average value and the second average value is calculated to obtain the evaluation index. Finally, when the evaluation index is greater than or equal to the third threshold value, the evaluation result of the underground coal gasification area to be evaluated is suitable for carrying out underground coal gasification; when the evaluation index is less than the third threshold value, the evaluation result of the underground coal gasification area to be evaluated is not suitable for carrying out underground coal gasification. The method of this embodiment takes into account the selection principle of the underground coal gasification area to be evaluated, and takes into account the actual situation that both the thickness value and the coal volatile matter may have multiple values. Under the above conditions, this embodiment only uses the product of two parameters to obtain the evaluation index, and can perform a preliminary and rapid evaluation of the underground coal gasification area according to the evaluation index. The method of this embodiment is simple and convenient to use, has a small amount of calculation, and is easy to understand and remember.

[0069] Embodiment three:

[0070] This embodiment proposes a method for evaluating underground coal gasification area selection, such as Figure 4 As shown, including:

[0071] Step S201: Selecting an underground coal gasification area to be evaluated;

[0072] In this embodiment, the selection principle of the underground coal gasification area to be evaluated is: select the underground coal gasification area where the coal resource volume is greater than the first threshold and the coal seam roof lithology density is greater than the second threshold as the underground coal gasification area to be evaluated. That is to say, in this embodiment, only when the coal resource volume in a certain area is large and the coal seam roof lithology is denser, will the area be considered as the underground coal gasification area to be evaluated.

[0073] Step S202: Obtain the thickness value of the underground coal seam and the volatile matter of the coal in the underground coal gasification selection area to be evaluated;

[0074] In this embodiment, the volatile content of coal refers to the yield of volatile organic matter after the coal is heated in an airtight state under specified conditions.

[0075] The coal volatile matter is the dry ash-free volatile matter of coal.

[0076] The thickness value ranges from [1.5m to 15m].

[0077] Step S203: Calculate the product of the thickness value and the volatile matter of the coal to obtain an evaluation index;

[0078] Step S204: When the evaluation index is greater than or equal to the third threshold, the evaluation result of the underground coal gasification area to be evaluated is suitable for carrying out underground coal gasification; when the evaluation index is less than the third threshold, the evaluation result of the underground coal gasification area to be evaluated is not suitable for carrying out underground coal gasification.

[0079] In actual situations, the thickness of a coal seam may have multiple different collected values ​​depending on the collection location. Similarly, there may be multiple coal volatiles collected at different locations. Therefore, to obtain an evaluation index, it is necessary to first take the average values ​​of the thickness value and the coal volatiles, respectively, and finally take the product of the two average values ​​as the evaluation index.

[0080] The product of the calculated thickness value and the volatile matter of the coal is used to obtain an evaluation index, including:

[0081] Calculate a first average value of the plurality of thickness values ​​and a second average value of the plurality of coal volatiles;

[0082] The product of the first average value and the second average value is calculated to obtain an evaluation index.

[0083] Step S205: when the evaluation result shows that there are multiple underground coal gasification areas to be evaluated that are suitable for carrying out underground coal gasification, sorting the corresponding multiple evaluation indexes from large to small;

[0084] Step S206: Select the underground coal gasification selection areas corresponding to the first M evaluation indexes from the ranking as the underground coal gasification selection areas that are ultimately suitable for carrying out underground coal gasification.

[0085] In this embodiment, considering that there may be multiple underground coal gasification selection areas to be evaluated that are suitable for carrying out underground coal gasification, it is necessary to sort all the evaluation indexes from large to small, and select the underground coal gasification selection areas corresponding to the first M evaluation indexes from the sorting as the underground coal gasification selection areas that are finally suitable for carrying out underground coal gasification. For example, in this embodiment, M=3, that is, the first 3 corresponding underground coal gasification selection areas with larger evaluation indexes are selected as the underground coal gasification selection areas that are finally suitable for carrying out underground coal gasification. Specifically, multiple blocks can be preferentially sorted according to the size of the product of the thickness value (H) of the coal seam and the volatile matter (V) of the coal. The larger the product result, that is, the larger the evaluation index, the higher the ranking, and the more suitable it is to carry out underground coal gasification.

[0086] The method for evaluating underground coal gasification zones proposed in this embodiment first requires selecting an underground coal gasification zone to be evaluated. When the coal resources are large and the lithology of the coal seam roof is dense, the product of the thickness value and the coal volatile matter is calculated to obtain an evaluation index. When there are multiple values ​​for both the thickness value and the coal volatile matter, a first average value of the multiple thickness values ​​and a second average value of the multiple coal volatile matters are calculated; the product of the first average value and the second average value is calculated to obtain an evaluation index. When the evaluation index is greater than or equal to a third threshold value, the evaluation result of the underground coal gasification zone to be evaluated is suitable for carrying out underground coal gasification; when the evaluation index is less than the third threshold value, the evaluation result of the underground coal gasification zone to be evaluated is not suitable for carrying out underground coal gasification. Finally, when there are multiple underground coal gasification zones to be evaluated whose evaluation results are suitable for carrying out underground coal gasification, the corresponding multiple evaluation indices are sorted from large to small; and the underground coal gasification zones corresponding to the first M evaluation indices are selected from the sorted order as the underground coal gasification zones finally suitable for carrying out underground coal gasification. The method of this embodiment not only takes into account the selection principle of the underground coal gasification zone to be evaluated, and the actual situation that the thickness value and the coal volatile matter may have multiple values, but also takes into account that when there are multiple evaluation results, this embodiment can still use the product of two parameters to obtain the evaluation index, and can perform a preliminary and rapid evaluation of the underground coal gasification zone based on the evaluation index. The method of this embodiment is simple and convenient to use, requires little calculation, and is easy to understand and remember.

[0087] Embodiment 4:

[0088] This embodiment is a specific example of implementation three, and the process of applying this application in a specific project is described in detail in the example.

[0089] Example 1:

[0090] Step S201: Selecting an underground coal gasification area to be evaluated;

[0091] In this example, in a certain area in the northern part of the Ordos Basin, the coal resources are relatively large and the main coal seam roof is mudstone, which meets the selection principle of the underground coal gasification area to be evaluated, that is, the underground coal gasification area with coal resources greater than the first threshold and the coal seam roof lithology density greater than the second threshold is selected as the underground coal gasification area to be evaluated.

[0092] Step S202: Obtain the thickness value of the underground coal seam and the volatile matter of the coal in the underground coal gasification selection area to be evaluated;

[0093] Step S203: Calculate the product of the thickness value and the volatile matter of the coal to obtain an evaluation index;

[0094] Step S204: When the evaluation index is greater than or equal to the third threshold, the evaluation result of the underground coal gasification area to be evaluated is suitable for carrying out underground coal gasification; when the evaluation index is less than the third threshold, the evaluation result of the underground coal gasification area to be evaluated is not suitable for carrying out underground coal gasification.

[0095] A main coal seam of the Jurassic system is located in a certain area in the northern part of the Ordos Basin. The general thickness is 2-5m, the average thickness of the coal seam is about 3.78m, and the maximum thickness of a single coal seam can reach 12.36m. The coal seam is mainly long flame coal, the volatile matter of coal is 30%-50%, and the average volatile matter of coal is about 43%. Using the average value, H×V=1.63>1.5, it is preliminarily evaluated that the coal seam is more suitable for underground coal gasification.

[0096] Example 2:

[0097] Step S201: Selecting an underground coal gasification area to be evaluated;

[0098] In this example, in a certain area in the eastern part of the Junggar Basin, the coal resources are relatively large and the main coal seam roof is mudstone, which also meets the selection principle of the underground coal gasification area to be evaluated, that is, the underground coal gasification area with coal resources greater than the first threshold and the coal seam roof lithology density greater than the second threshold is selected as the underground coal gasification area to be evaluated.

[0099] Step S202: Obtain the thickness value of the underground coal seam and the volatile matter of the coal in the underground coal gasification selection area to be evaluated;

[0100] Step S203: Calculate the product of the thickness value and the volatile matter of the coal to obtain an evaluation index;

[0101] Step S204: When the evaluation index is greater than or equal to the third threshold, the evaluation result of the underground coal gasification area to be evaluated is suitable for carrying out underground coal gasification; when the evaluation index is less than the third threshold, the evaluation result of the underground coal gasification area to be evaluated is not suitable for carrying out underground coal gasification.

[0102] In this example, in a certain area in the eastern part of the Junggar Basin, a coal seam of the Xishanyao Formation is generally about 12m thick. 12m is directly used as the thickness value of the coal seam. The coal seam has good continuity, and the degree of coal metamorphism increases from north to south. It mainly develops into lignite and long flame coal. The coal rank is low and the volatile matter is high, generally 50%-70%. The average volatile matter of coal is about 62%. Using the average value, H×V=7.44>1.5. It is preliminarily evaluated that the coal seam is more suitable for underground coal gasification.

[0103] Comparison of Example 1 and Example 2:

[0104] When the evaluation result shows that there are multiple underground coal gasification selection areas to be evaluated that are suitable for carrying out underground coal gasification, the corresponding multiple evaluation indexes are sorted from large to small; and the underground coal gasification selection areas corresponding to the first M evaluation indexes are selected from the sorting as the underground coal gasification selection areas that are finally suitable for carrying out underground coal gasification.

[0105] By comparing the rapid evaluation indexes of underground coal gasification selection areas in these two regions, the coal seams in the Junggar Basin (evaluation index is 7.44) are significantly better than those in the Ordos Basin (evaluation index is 1.63). Therefore, the coal seams in the Junggar Basin are ranked higher.

[0106] This embodiment uses two examples to elaborate the application process of the method for evaluating underground coal gasification selection area of ​​this application. In the prior art, the selection area evaluation method and model of underground coal gasification involve a large number of geological parameters, and the calculation process is also quite complicated, so it is very inconvenient to use. This embodiment uses the two most basic and most critical geological parameters, the thickness value of the coal seam (H) and the volatile matter of the coal (V), and uses the product of the two as a rapid evaluation index, which can not only perform a preliminary rapid evaluation of the underground coal gasification selection area, but also can quantitatively rank the selection area, which has the characteristics of being simple, convenient, easy to understand and remember, etc.

[0107] Embodiment five:

[0108] This embodiment provides a device for evaluating underground coal gasification area selection, such as Figure 5 As shown, it includes: a data acquisition module, a product calculation module, and an evaluation result output module;

[0109] The data acquisition module is connected to the product calculation module, and the product calculation module is connected to the evaluation result output module;

[0110] A data acquisition module is used to obtain the thickness of underground coal seams and coal volatiles in the underground coal gasification area to be evaluated;

[0111] The product calculation module is used to calculate the product of the thickness value and the volatile matter of the coal to obtain the evaluation index;

[0112] An evaluation result output module is used to, when the evaluation index is greater than or equal to a third threshold, determine that the evaluation result of the underground coal gasification selection area to be evaluated is suitable for carrying out underground coal gasification; when the evaluation index is less than the third threshold, determine that the evaluation result of the underground coal gasification selection area to be evaluated is not suitable for carrying out underground coal gasification.

[0113] The device for evaluating underground coal gasification zone selection further comprises:

[0114] A selection area module, connected to the data acquisition module, for selecting an underground coal gasification area to be evaluated;

[0115] The selection principle of the underground coal gasification area to be evaluated is: select the underground coal gasification area with coal resources greater than the first threshold and the coal seam roof lithology density greater than the second threshold as the underground coal gasification area to be evaluated.

[0116] The device for evaluating underground coal gasification zone selection further comprises:

[0117] A sorting module is connected to the evaluation result output module and is used to sort the corresponding multiple evaluation indexes from large to small when the evaluation result shows that there are multiple underground coal gasification selection areas to be evaluated that are suitable for carrying out underground coal gasification; and select the underground coal gasification selection areas corresponding to the first M evaluation indexes from the sorting as the underground coal gasification selection areas that are finally suitable for carrying out underground coal gasification.

[0118] The device for evaluating underground coal gasification selection area proposed in this embodiment uses a data acquisition module to obtain the thickness value of the underground coal seam and the coal volatile matter in the underground coal gasification selection area to be evaluated; uses a product calculation module to calculate the product of the thickness value and the coal volatile matter to obtain an evaluation index; finally, uses an evaluation result output module to determine that the evaluation result of the underground coal gasification selection area to be evaluated is suitable for carrying out underground coal gasification when the evaluation index is greater than or equal to a third threshold value; and when the evaluation index is less than the third threshold value, the evaluation result of the underground coal gasification selection area to be evaluated is not suitable for carrying out underground coal gasification. The device of this embodiment uses the product of two parameters to obtain the evaluation index, and can perform a preliminary and rapid evaluation of the underground coal gasification selection area based on the evaluation index. The device is simple and convenient to use, has a small amount of calculation, and is easy to understand and remember.

[0119] Embodiment six:

[0120] This embodiment proposes an electronic device, including: a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the method for evaluating underground coal gasification selection is executed.

[0121] The electronic device may be a mobile phone, a computer or a tablet computer, etc., including a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method for evaluating the selection area of ​​underground coal gasification as described in the embodiment is implemented. It is understood that the electronic device may also include an input / output (I / O) interface and a communication component.

[0122] The processor is used to execute all or part of the steps in the method for evaluating underground coal gasification area selection as described in the above embodiment. The memory is used to store various types of data, which may include instructions of any application or method in the electronic device, as well as data related to the application.

[0123] The processor can be an application specific integrated circuit (ASIC), a digital signal processor (DSP), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller, a microprocessor or other electronic components, and is used to execute the method for evaluating underground coal gasification zones described in the above embodiments.

[0124] Embodiment seven:

[0125] This embodiment provides a computer-readable storage medium storing executable instructions, which, when executed, enable a processor to execute the method for evaluating underground coal gasification zones.

[0126] If implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium.

[0127] Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method for evaluating underground coal gasification selection areas described in the various embodiments of the present application.

[0128] The aforementioned storage media include: flash memory, hard disk, multimedia card, card-type memory (for example, SD (Secure Digital Memory Card) or DX (Memory Data Register, MDR abbreviation, memory data register) memory, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, CD, server, APP (Application, abbreviation of application software) application store and other media that can store program verification codes, on which computer programs are stored. When the computer program is executed by the processor, the various steps of the above-mentioned method for evaluating underground coal gasification selection can be implemented.

[0129] The various embodiments in the present disclosure are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0130] The protection scope of the present disclosure is not limited to the above-mentioned embodiments. Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the scope and spirit of the present disclosure. If these changes and modifications fall within the scope of the claims of the present disclosure and their equivalents, the intention of the present disclosure also includes these changes and modifications.

Claims

1. A method for evaluating underground coal gasification area selection, characterized in that: include: Obtain the thickness of underground coal seams and coal volatiles in the underground coal gasification area to be evaluated; Calculate the product of the thickness value and the volatile matter of the coal to obtain the evaluation index; When the evaluation index is greater than or equal to the third threshold, the evaluation result of the underground coal gasification area to be evaluated is suitable for carrying out underground coal gasification; When the evaluation index is less than the third threshold value, the result of the evaluation of the underground coal gasification area to be evaluated is that it is not suitable for carrying out underground coal gasification.

2. The method for evaluating underground coal gasification zones according to claim 1, characterized in that: The method for evaluating underground coal gasification area selection further includes: Select the underground coal gasification area to be evaluated; The selection principle of the underground coal gasification area to be evaluated is: select the underground coal gasification area whose coal resource volume is greater than a first threshold and the coal seam roof lithology density is greater than a second threshold as the underground coal gasification area to be evaluated.

3. The method for evaluating underground coal gasification area selection according to claim 1, characterized in that: The thickness value is multiple, and the coal volatilization is multiple; The product of the calculated thickness value and the volatile matter of the coal is used to obtain an evaluation index, including: Calculate a first average value of the plurality of thickness values ​​and a second average value of the plurality of coal volatiles; The product of the first average value and the second average value is calculated to obtain an evaluation index.

4. The method for evaluating underground coal gasification area selection according to claim 3, characterized in that: The method for evaluating underground coal gasification area selection further includes: When the evaluation result shows that there are multiple underground coal gasification areas to be evaluated that are suitable for carrying out underground coal gasification, the corresponding multiple evaluation indexes are sorted from large to small; The underground coal gasification selection areas corresponding to the first M evaluation indexes are selected from the ranking as the underground coal gasification selection areas that are ultimately suitable for carrying out underground coal gasification.

5. The method for evaluating underground coal gasification area selection according to claim 1, characterized in that: The volatile content of coal refers to the yield of volatile organic matter after coal is heated in an airtight state under specified conditions.

6. The method for evaluating underground coal gasification area selection according to claim 5, characterized in that: The coal volatile matter is the dry ash-free volatile matter of coal.

7. The method for evaluating underground coal gasification area selection according to claim 1, characterized in that: The thickness value ranges from [1.5m to 15m].

8. A device for evaluating underground coal gasification zone selection, characterized in that: include: A data acquisition module is used to obtain the thickness of underground coal seams and coal volatiles in the underground coal gasification area to be evaluated; The product calculation module is used to calculate the product of the thickness value and the volatile matter of the coal to obtain the evaluation index; An evaluation result output module, configured to output, when the evaluation index is greater than or equal to a third threshold value, an evaluation result of the underground coal gasification area to be evaluated is suitable for carrying out underground coal gasification; When the evaluation index is less than the third threshold value, the result of the evaluation of the underground coal gasification area to be evaluated is that it is not suitable for carrying out underground coal gasification.

9. An electronic device, characterized in that: include: A memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method for evaluating underground coal gasification areas according to any one of claims 1 to 7 is executed.

10. A computer-readable storage medium, characterized in that: It stores executable instructions, which, when executed, enable the processor to execute the method for evaluating underground coal gasification areas as described in any one of claims 1-7.

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