阅读说明：本技术 煤成气中煤系煤岩和泥岩贡献率碳同位素评价方法及装置 (Method and device for evaluating carbon isotope of coal-series coal rock and mudstone contribution rate in coal gasification ) 是由 李剑 王晓波 魏国齐 谢增业 李志生 国建英 王义凤 郝爱胜 崔会英 潘松圻 杨 于 2019-02-19 设计创作，主要内容包括：本发明提供一种煤成气中煤系煤岩和泥岩贡献率碳同位素评价方法及装置,该方法包括获取研究区已确定的煤成气样品中甲烷碳同位素分布范围、乙烷碳同位素分布范围及甲烷碳同位素分布范围差、乙烷碳同位素分布范围差；判读甲烷碳同位素分布范围差、乙烷碳同位素分布范围差的大小,并将碳同位素分布范围差较大的烷烃的碳同位素数据作为评价煤成气中煤系煤岩和泥岩贡献率的参数；根据煤成气碳同位素分布范围差较大的烷烃碳同位素数据的平均值、研究区煤系泥岩热模拟气碳同位素分布范围差较大的烷烃碳同位素数据最小端元值及研究区煤系煤岩热模拟气碳同位素分布范围差较大的烷烃碳同位素数据最大端元值,分别获得研究区煤成气中煤系煤岩和泥岩的贡献率。(The invention provides a method and a device for evaluating carbon isotopes of coal-series coal rock and mudstone contribution rate in coal-formed gas, wherein the method comprises the steps of obtaining a methane carbon isotope distribution range, an ethane carbon isotope distribution range, a methane carbon isotope distribution range difference and an ethane carbon isotope distribution range difference in a coal-formed gas sample determined in a research area; judging the size of the difference of the distribution range of the carbon isotopes of methane and the size of the difference of the distribution range of the carbon isotopes of ethane, and taking the carbon isotope data of the alkane with the larger difference of the distribution range of the carbon isotopes as parameters for evaluating the contribution rate of coal-series coal rock and mudstone in the coal-forming gas; and respectively obtaining the contribution rates of the coal-series coal rock and the mudstone in the coal-formed gas of the research area according to the average value of the alkane carbon isotope data with larger coal-formed gas carbon isotope distribution range difference, the minimum end-member value of the alkane carbon isotope data with larger coal-series mudstone thermal simulation gas carbon isotope distribution range difference of the research area and the maximum end-member value of the alkane carbon isotope data with larger coal-series coal rock thermal simulation gas carbon isotope distribution range difference of the research area.)

1. A method for evaluating carbon isotopes in coal-series coal rock and mudstone contribution rate in coal-forming gas is characterized by comprising the following steps:

acquiring a methane carbon isotope distribution range, an ethane carbon isotope distribution range, a methane carbon isotope distribution range difference and an ethane carbon isotope distribution range difference in a coal gas sample determined in a research area;

judging the size of the difference of the distribution range of the carbon isotopes of methane and the size of the difference of the distribution range of the carbon isotopes of ethane, and taking the carbon isotope data of the alkane with the larger difference of the distribution range of the carbon isotopes as parameters for evaluating the contribution rate of coal-series coal rock and mudstone in the coal-forming gas;

and respectively obtaining the contribution rates of the coal-series coal rock and the mudstone in the coal-series gas of the research area according to the average value of the alkane carbon isotope data with larger coal-forming gas carbon isotope distribution range difference, the minimum end-member value of the alkane carbon isotope data with larger coal-series mudstone thermal simulation gas carbon isotope distribution range difference of the research area and the maximum end-member value of the alkane carbon isotope data with larger coal-series coal rock thermal simulation gas carbon isotope distribution range difference of the research area.

2. The method of claim 1, further comprising, before obtaining the range of methane carbon isotope distribution, the range of ethane carbon isotope distribution, and the range difference of methane carbon isotope distribution and the range difference of ethane carbon isotope distribution in the coal gas sample determined in the research area:

and acquiring the data of alkane series carbon isotopes in the natural gas sample of the research area to judge whether the natural gas sample is coal-formed gas.

3. The method of claim 2, wherein the obtaining of the alkane series carbon isotope data in the natural gas sample of the research area to determine whether the natural gas sample is coal-formed gas comprises:

and acquiring alkane series carbon isotope data in a natural gas sample in a research area, and judging whether the natural gas sample is coal gas or not according to the alkane carbon isotope sequence, the methane carbon isotope data and the ethane carbon isotope data.

4. The method of claim 2 or 3, wherein the alkane series carbon isotope data includes at least carbon isotope data of methane and carbon isotope data of ethane.

5. The method according to claim 1, wherein the contribution rates of the coal-derived gas coal-derived rock and the mudstone in the research area are respectively obtained according to the following formula 1) and formula 2) according to the average value of the alkane carbon isotope data with a large difference in the coal-derived gas carbon isotope distribution range, the minimum end-member value of the alkane carbon isotope data with a large difference in the thermal simulated gas carbon isotope distribution range of the mudstone in the research area, and the maximum end-member value of the alkane carbon isotope data with a large difference in the thermal simulated gas carbon isotope distribution range of the coal-derived gas shale in the research area:

X＝(C_iaverage-C_icoal series mudstone end member_min)/(C_iCoal series coal rock end member_max-C_iCoal series mudstone end member_min) × 100% equation 1);

y ═ 100% -X formula 2);

in the formula 1) and the formula 2), X is the contribution rate of coal-series coal rocks in the coal gasification gas;

y is the contribution rate of coal-series mudstone in coal gasification;

C_iaveragethe average value of the alkane carbon isotope data with larger distribution range difference of the carbon isotopes of the coal gas is obtained;

C_{i coal series mudstone end member min}For the coal series of the research areaThe minimum end-member value of alkane carbon isotope data with large difference of distribution range of gas carbon isotopes is simulated by mudstone heat;

C_{i coal series coal rock end member max}Simulating the maximum end-member value of the alkane carbon isotope data with large gas carbon isotope distribution range difference for the coal measure coal rock thermal simulation of the research area;

i is 1 or 2.

6. The method according to claim 1, wherein when the minimum end-member value of the alkane carbon isotope data with a large difference in the thermal simulated gas carbon isotope distribution range of the coal-series mudstone of the research area and/or the maximum end-member value of the alkane carbon isotope data with a large difference in the thermal simulated gas carbon isotope distribution range of the coal-series mudstone of the research area cannot be obtained, the contribution rates of the coal-series coal rock and the mudstone in the coal-series mudstone of the research area are respectively obtained according to the average value of the alkane carbon isotope data with a large difference in the coal-gas carbon isotope distribution range, the minimum end-member value of the alkane carbon isotope data with a large difference in the coal-gas carbon isotope distribution range and/or the maximum end-member value of the alkane carbon isotope data with a large difference in the coal-gas carbon isotope distribution range.

7. The method as claimed in claim 6, wherein the contribution rates of coal-based coal petrography and mudstone in coal-derived gas in the research area are respectively obtained according to the following formula 3) and formula 4) according to the average value of the alkane carbon isotope data with large coal-derived gas carbon isotope distribution range difference, the minimum end-member value of the alkane carbon isotope data with large coal-derived gas carbon isotope distribution range difference and/or the maximum end-member value of the alkane carbon isotope data with large coal-derived gas carbon isotope distribution range difference:

X＝(C_iaverage-C_{i coal series mudstone end member min}Or C_imin)/(C_{i coal series coal rock end member max}Or C_imax-C_{i coal series mudstone end member min}Or Ci_min) × 100% equation 3);

y ═ 100% to X formula 4);

in the formula 3) and the formula 4), X is the contribution rate of coal-series coal rocks in the coal gasification gas;

y is the contribution rate of coal-series mudstone in coal gasification;

C_iminthe minimum end-member value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference is obtained;

C_imaxthe maximum end-member value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference is obtained;

C_iaveragethe average value of the alkane carbon isotope data with larger distribution range difference of the carbon isotopes of the coal gas is obtained;

C_{i coal series mudstone end member min}Simulating the minimum end-member value of alkane carbon isotope data with larger gas carbon isotope distribution range difference for the coal series mudstone thermal simulation of the research area;

C_{i coal series coal rock end member max}Simulating the maximum end-member value of the alkane carbon isotope data with large gas carbon isotope distribution range difference for the coal measure coal rock thermal simulation of the research area;

i is 1 or 2.

8. The method according to claim 6 or 7, wherein the average value of the alkane carbon isotope data with the larger difference in the coal gas carbon isotope distribution range, the minimum end-member value of the alkane carbon isotope data with the larger difference in the coal gas carbon isotope distribution range and/or the maximum end-member value of the alkane carbon isotope data with the larger difference in the coal gas carbon isotope distribution range is obtained according to the alkane carbon isotope distribution range with the larger difference in the carbon isotope distribution range in the coal gas sample which has been determined in the research area.

9. A coal measures coal petrography and mudstone contribution rate carbon isotope evaluation device in coal gasification, its characterized in that includes:

the first data acquisition module is used for acquiring a methane carbon isotope distribution range, an ethane carbon isotope distribution range, a methane carbon isotope distribution range difference and an ethane carbon isotope distribution range difference in a coal gas sample determined in a research area;

the data comparison and evaluation parameter determination module is used for judging the size of the difference of the distribution range of the methane carbon isotopes and the size of the difference of the distribution range of the ethane carbon isotopes, and taking the carbon isotope data of the alkane with the larger difference of the distribution range of the carbon isotopes as parameters for evaluating the contribution rate of coal-series coal rock and mudstone in the coal gas;

the first contribution rate obtaining module is used for respectively obtaining the contribution rates of the coal-series coal petrography and the mudstone in the research area according to the average value of the alkane carbon isotope data with larger coal-series gas carbon isotope distribution range difference, the minimum end-member value of the alkane carbon isotope data with larger research area coal-series mudstone thermal simulation gas carbon isotope distribution range difference and the maximum end-member value of the alkane carbon isotope data with larger research area coal-series coal rock thermal simulation gas carbon isotope distribution range difference.

10. The apparatus of claim 9, further comprising:

and the second data acquisition module is used for acquiring the alkane series carbon isotope data in the natural gas sample in the research area so as to judge whether the natural gas sample is coal-formed gas.

11. The apparatus of claim 10, wherein the second data acquisition module is specifically configured to:

and acquiring alkane series carbon isotope data in a natural gas sample in a research area, and judging whether the natural gas sample is coal gas or not according to the alkane carbon isotope sequence, the methane carbon isotope data and the ethane carbon isotope data.

12. The apparatus of claim 10 or 11, wherein the second data acquisition module is further configured to:

the method comprises the steps of obtaining alkane series carbon isotope data at least comprising methane and ethane carbon isotope data in a natural gas sample in a research area, and judging whether the natural gas sample is coal-formed gas or not according to the alkane carbon isotope sequence and the methane and ethane carbon isotope data.

13. The apparatus according to claim 9, wherein the first contribution rate obtaining module is specifically configured to:

according to the average value of the alkane carbon isotope data with large coal gas isotope distribution range difference, the minimum end-member value of the alkane carbon isotope data with large research area coal-series mudstone thermal simulation gas carbon isotope distribution range difference and the maximum end-member value of the alkane carbon isotope data with large research area coal-series mudstone thermal simulation gas carbon isotope distribution range difference, the contribution rates of the coal-series coal rock and the mudstone in the coal gas of the research area are respectively obtained according to the following formula 1) and formula 2):

X＝(C_iaverage-C_{i coal series mudstone end member min})/(C_{i coal series coal rock end member max}-C_{i coal series mudstone end member min}) × 100% equation 1);

y ═ 100% -X formula 2);

in the formula 1) and the formula 2), X is the contribution rate of coal-series coal rocks in the coal gasification gas;

y is the contribution rate of coal-series mudstone in coal gasification;

C_iaveragethe average value of the alkane carbon isotope data with larger distribution range difference of the carbon isotopes of the coal gas is obtained;

C_{i coal series mudstone end member min}Simulating the minimum end-member value of alkane carbon isotope data with larger gas carbon isotope distribution range difference for the coal series mudstone thermal simulation of the research area;

C_{i coal series coal rock end member max}Simulating the maximum end-member value of the alkane carbon isotope data with large gas carbon isotope distribution range difference for the coal measure coal rock thermal simulation of the research area;

i is 1 or 2.

14. The apparatus of claim 9, further comprising a second contribution rate obtaining module configured to:

when the minimum end-member value of the alkane carbon isotope data with large difference of the distribution range of the coal-series mudstone thermal simulation gas carbon isotopes in the research area and/or the maximum end-member value of the alkane carbon isotope data with large difference of the distribution range of the coal-series mudstone thermal simulation gas carbon isotopes in the research area cannot be obtained, the contribution rates of the coal-series coal rock and the mudstone in the coal-series mudstone in the research area are respectively obtained according to the average value of the alkane carbon isotope data with large difference of the distribution range of the coal-gas carbon isotopes, the minimum end-member value of the alkane carbon isotope data with large difference of the distribution range of the coal-gas carbon isotopes and/or the maximum end-member value of the alkane carbon isotope data with large difference of the distribution range of the coal-gas carbon isotopes.

15. The apparatus according to claim 14, wherein the second contribution rate obtaining module is specifically configured to:

according to the average value of the alkane carbon isotope data with the large coal gas carbon isotope distribution range difference, the minimum end member value of the alkane carbon isotope data with the large coal gas carbon isotope distribution range difference and/or the maximum end member value of the alkane carbon isotope data with the large coal gas carbon isotope distribution range difference, the contribution rates of coal series coal rocks and mudstones in the coal gas of the research area are respectively obtained according to the following formula 3) and formula 4):

X＝(C_iaverage-C_{i coal series mudstone end member min}Or C_imin)/(C_{i coal series coal rock end member max}Or C_imax-C_{i coal series mudstone end member min}Or C_imin) × 100% equation 3);

y ═ 100% to X formula 4);

in the formula 3) and the formula 4), X is the contribution rate of coal-series coal rocks in the coal gasification gas;

y is the contribution rate of coal-series mudstone in coal gasification;

C_iminthe minimum end-member value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference is obtained;

C_imaxthe maximum end-member value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference is obtained;

C_iaveragethe average value of the alkane carbon isotope data with larger distribution range difference of the carbon isotopes of the coal gas is obtained;

C_{i coal series mudstone end member min}Simulating the minimum end-member value of alkane carbon isotope data with larger gas carbon isotope distribution range difference for the coal series mudstone thermal simulation of the research area;

C_{i coal series coal rock end member max}For the coal-series coal petrography heat of the research areaSimulating the maximum end member value of alkane carbon isotope data with larger gas carbon isotope distribution range difference;

i is 1 or 2.

16. The apparatus of claim 14 or 15, further comprising a third data acquisition module configured to:

according to the alkane carbon isotope distribution range with larger carbon isotope distribution range difference in the coal gas sample determined in the research area, the average value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference, the minimum end-member value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference and/or the maximum end-member value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference are obtained.

17. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to implement the method for evaluating carbon isotopes in coal-based coal petrography and mudstone contribution rate of coal-derived gas according to any one of claims 1 to 8.

18. A computer-readable storage medium storing a computer program for executing the method for evaluating carbon isotopes in coal-derived coal and mudstone contribution rate in coal-derived gas according to any one of claims 1 to 8.

Technical Field

The invention relates to a method and a device for evaluating carbon isotopes in coal-series coal rock and mudstone contribution rate in coal-forming gas, and belongs to the technical field of gas source comparison and resource evaluation in natural gas exploration.

Background

The natural gas of China is mainly coal gas, and the coal gas accounts for about 70% of the natural gas of China and mainly comes from coal-series hydrocarbon source rocks. Therefore, as an important gas source rock, the coal-based hydrocarbon source rock plays an important role in China, and plays an extremely important role in the hydrocarbon source rock for the development of the natural gas industry in China. The coal-series hydrocarbon source rocks comprise two main types of coal-series coal rocks and coal-series mudstone, wherein the organic matter type of the coal-series coal rocks is a typical humus type, the abundance TOC of the organic matter is high, and the total thickness is relatively small; the coal-series mudstone has a partial rotten mud type organic matter type, relatively low organic matter abundance TOC and relatively large total thickness. The method has the advantages that the contribution of coal rock and mudstone in the coal-series hydrocarbon source rock is determined, and the method has important significance for optimizing favorable zones of a coal-series hydrocarbon source rock distribution area, evaluating favorable targets and guiding exploration. The research on the cause and the source of natural gas in the current oil and gas exploration generally only needs to determine whether a natural gas field (reservoir) is coal gas or oil gas, whether the natural gas field (reservoir) is from coal-series source rocks or sapropel-type source rocks, and whether the natural gas field (reservoir) is from which coal-series source rocks or sapropel-type source rocks, and no further deep research on the contribution of the coal rocks and the mudrocks in the determined natural gas field (reservoir) from the coal-series source rocks is carried out. When natural gas resource evaluation of a coal-based hydrocarbon source rock distribution area is carried out, a large number of hydrocarbon source rock thermal simulation experiment methods are generally required to be carried out to obtain gas production rates of coal rocks and mudstones in a research area, gas production amounts of the coal rocks and the mudstones in the coal-based hydrocarbon source rocks are respectively calculated by combining thicknesses, organic matter abundances and distribution areas of the coal rocks and the mudstones, and finally contribution of the coal-based coal rocks or the mudstones in a natural gas field (reservoir) is roughly estimated according to the gas production amounts of the coal-based mudstones and the coal rocks. The method needs a large amount of basic data, the calculation process is complex and tedious, the workload is huge, the experimental simulation data is greatly influenced by experimental conditions, human factors, sample non-mean values and the like, and the gas generation data cannot reflect the influence of the transportation accumulation dissipation process in the later period, so the method is tedious, and the accuracy and the reliability of the calculation result are relatively poor.

Therefore, a method and a device for quickly, effectively and accurately quantitatively evaluating coal rock and mudstone contributions from coal-based hydrocarbon source rocks in coal-derived gas are needed.

Disclosure of Invention

In order to solve the above disadvantages and shortcomings, an object of the present invention is to provide a method for evaluating carbon isotopes in coal-based coal rock and mudstone contribution rate in coal-derived gas. The quantitative evaluation method provided by the invention can quickly, accurately and effectively quantitatively evaluate the coal rock and mudstone contribution of the coal-series hydrocarbon source rock in the coal-derived gas, and provides technical support for deepening the research on the cause and source of natural gas and guiding the exploration of the coal-derived gas.

The invention also aims to provide a carbon isotope evaluation device for coal-based coal rock and mudstone contribution rate in coal-forming gas.

It is also an object of the invention to provide a computer apparatus.

It is still another object of the present invention to provide a computer-readable storage medium.

In order to achieve the above object, in one aspect, the present invention provides a method for evaluating carbon isotopes in coal-derived coal petrography and mudstone contribution rate in coal-derived gas, wherein the method includes:

acquiring a methane carbon isotope distribution range, an ethane carbon isotope distribution range, a methane carbon isotope distribution range difference and an ethane carbon isotope distribution range difference in a coal gas sample determined in a research area;

judging the size of the difference of the distribution range of the carbon isotopes of methane and the size of the difference of the distribution range of the carbon isotopes of ethane, and taking the carbon isotope data of the alkane with the larger difference of the distribution range of the carbon isotopes as parameters for evaluating the contribution rate of coal-series coal rock and mudstone in the coal-forming gas;

and respectively obtaining the contribution rates of the coal-series coal rock and the mudstone in the coal-series gas of the research area according to the average value of the alkane carbon isotope data with larger coal-forming gas carbon isotope distribution range difference, the minimum end-member value of the alkane carbon isotope data with larger coal-series mudstone thermal simulation gas carbon isotope distribution range difference of the research area and the maximum end-member value of the alkane carbon isotope data with larger coal-series coal rock thermal simulation gas carbon isotope distribution range difference of the research area.

According to an embodiment of the invention, a stainless steel high pressure cylinder with a double valve may be used to collect the natural gas sample from the research area in the method.

Wherein the gas pressure of the stainless steel high-pressure steel cylinder is 3-6 MPa.

According to an embodiment of the present invention, in the method, before obtaining the range of distribution of the methane carbon isotopes, the range of distribution of the ethane carbon isotopes, and the difference of the range of distribution of the methane carbon isotopes and the difference of the range of distribution of the ethane carbon isotopes in the coal gas sample determined in the research area, the method further preferably comprises:

and acquiring the data of alkane series carbon isotopes in the natural gas sample of the research area to judge whether the natural gas sample is coal-formed gas.

According to an embodiment of the present invention, in the method, preferably, the acquiring data of the alkane series carbon isotopes in the natural gas sample in the research area to determine whether the natural gas sample is coal-formed gas includes:

acquiring the carbon isotope data of alkane series in a natural gas sample of a research area and obtaining the carbon isotope data according to the carbon isotope sequence (C) of alkane₁、C₂、C₃、C₄) And judging whether the natural gas sample is coal gas or not according to the methane carbon isotope data and the ethane carbon isotope data.

In the method according to an embodiment of the present invention, preferably, the alkane series carbon isotope data includes at least carbon isotope data of methane and carbon isotope data of ethane.

According to an embodiment of the present invention, in the method, preferably, the contribution rates of the coal-series coal petrography and the mudstone in the coal-series gas of the research area are respectively obtained according to the following formula 1) and formula 2) according to an average value of the alkane carbon isotope data with a large difference in the coal-series gas carbon isotope distribution range, a minimum end-member value of the alkane carbon isotope data with a large difference in the thermal simulated gas carbon isotope distribution range of the mudstone of the coal-series mudstone of the research area, and a maximum end-member value of the alkane carbon isotope data with a large difference in the thermal simulated gas carbon isotope distribution range of the coal-series mudstone of the research area:

X＝(C_iaverage-C_{i coal series mudstone end member min})/(C_{i coal series coal rock end member max}-C_{i coal series mudstone end member min}) × 100% equation 1);

y ═ 100% -X formula 2);

in the formula 1) and the formula 2), X is the contribution rate of coal-series coal rocks in the coal gasification gas;

y is the contribution rate of coal-series mudstone in coal gasification;

C_iaveragethe average value of the alkane carbon isotope data with larger distribution range difference of the carbon isotopes of the coal gas is obtained;

C_{i coal series mudstone end member min}Is the research areaThe minimum end-member value of the alkane carbon isotope data with large distribution range difference of the coal series mudstone thermal simulation gas carbon isotopes;

C_{i coal series coal rock end member max}Simulating the maximum end-member value of the alkane carbon isotope data with large gas carbon isotope distribution range difference for the coal measure coal rock thermal simulation of the research area;

i is 1 or 2.

According to the specific embodiment of the invention, in the method, the paraffin carbon isotope data C with large differences in the distribution range of the coal-series coal petrography thermal simulation gas carbon isotopes in the research area is used for considering that the kerogen carbon isotopes of the coal-series coal petrography are relatively heavy, the kerogen carbon isotopes of the coal-series mudstone are relatively light, the natural gas generated by the coal-series coal petrography is also relatively heavy and the natural gas generated by the coal-series mudstone is also relatively light according to the matrix continuing effect_{i coal series coal rock end member max}The alkane carbon isotope data C with larger distribution range difference of the thermal simulation gas carbon isotopes of the coal series mudstone in the research area is the maximum end member_{i coal series mudstone end member min}Is the smallest end member.

According to an embodiment of the present invention, in the method, preferably, when the minimum end-member value of the alkane carbon isotope data with a large difference in the thermal simulated gas carbon isotope distribution range of the coal-series mudstone in the research area and/or the maximum end-member value of the alkane carbon isotope data with a large difference in the thermal simulated gas carbon isotope distribution range of the coal-series mudstone in the research area cannot be obtained, the contribution rates of the coal-series coal rock and the mudstone in the coal-series gas in the research area are respectively obtained according to the average value of the alkane carbon isotope data with a large difference in the coal-gas carbon isotope distribution range, the minimum end-member value of the alkane carbon isotope data with a large difference in the coal-gas carbon isotope distribution range and/or the maximum end-member value of the alkane carbon isotope data with a large difference in the coal-gas carbon isotope distribution range.

According to an embodiment of the present invention, in the method, preferably, the contribution rates of coal-derived coal petrography and mudstone in coal gas in the research area are obtained according to the following formula 3) and formula 4) according to an average value of the alkane carbon isotope data with a large difference in coal gas carbon isotope distribution range, a minimum end-member value of the alkane carbon isotope data with a large difference in coal gas carbon isotope distribution range and/or a maximum end-member value of the alkane carbon isotope data with a large difference in coal gas carbon isotope distribution range:

X＝(C_iaverage-C_{i coal series mudstone end member min}Or C_imin)/(C_{i coal series coal rock end member max}Or C_imax-C_{i coal series mudstone end member min}Or C_imin) × 100% equation 3);

y ═ 100% to X formula 4);

in the formula 3) and the formula 4), X is the contribution rate of coal-series coal rocks in the coal gasification gas;

y is the contribution rate of coal-series mudstone in coal gasification;

C_iminthe minimum end-member value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference is obtained;

C_imaxthe maximum end-member value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference is obtained;

C_iaveragethe average value of the alkane carbon isotope data with larger distribution range difference of the carbon isotopes of the coal gas is obtained;

C_{i coal series mudstone end member min}Simulating the minimum end-member value of alkane carbon isotope data with larger gas carbon isotope distribution range difference for the coal series mudstone thermal simulation of the research area;

C_{i coal series coal rock end member max}Simulating the maximum end-member value of the alkane carbon isotope data with large gas carbon isotope distribution range difference for the coal measure coal rock thermal simulation of the research area;

i is 1 or 2.

According to an embodiment of the present invention, in the method, preferably, an average value of the alkane carbon isotope data with the larger difference in the coal gas carbon isotope distribution ranges, a minimum end-member value of the alkane carbon isotope data with the larger difference in the coal gas carbon isotope distribution ranges and/or a maximum end-member value of the alkane carbon isotope data with the larger difference in the coal gas carbon isotope distribution ranges is obtained according to the alkane carbon isotope distribution ranges with the larger difference in the coal gas carbon isotope distribution ranges in the coal gas sample determined by the research area.

On the other hand, the invention also provides a carbon isotope evaluation device for coal-series coal rock and mudstone contribution rate in coal-forming gas, which comprises the following components:

the first data acquisition module is used for acquiring a methane carbon isotope distribution range, an ethane carbon isotope distribution range, a methane carbon isotope distribution range difference and an ethane carbon isotope distribution range difference in a coal gas sample determined in a research area;

the data comparison and evaluation parameter determination module is used for judging the size of the difference of the distribution range of the methane carbon isotopes and the size of the difference of the distribution range of the ethane carbon isotopes, and taking the carbon isotope data of the alkane with the larger difference of the distribution range of the carbon isotopes as parameters for evaluating the contribution rate of coal-series coal rock and mudstone in the coal gas;

the first contribution rate obtaining module is used for respectively obtaining the contribution rates of the coal-series coal petrography and the mudstone in the research area according to the average value of the alkane carbon isotope data with larger coal-series gas carbon isotope distribution range difference, the minimum end-member value of the alkane carbon isotope data with larger research area coal-series mudstone thermal simulation gas carbon isotope distribution range difference and the maximum end-member value of the alkane carbon isotope data with larger research area coal-series coal rock thermal simulation gas carbon isotope distribution range difference.

According to a specific embodiment of the present invention, preferably, the apparatus further comprises:

and the second data acquisition module is used for acquiring the alkane series carbon isotope data in the natural gas sample in the research area so as to judge whether the natural gas sample is coal-formed gas.

According to an embodiment of the present invention, in the apparatus, preferably, the second data obtaining module is specifically configured to:

and acquiring alkane series carbon isotope data in a natural gas sample in a research area, and judging whether the natural gas sample is coal gas or not according to the alkane carbon isotope sequence, the methane carbon isotope data and the ethane carbon isotope data.

According to a specific embodiment of the present invention, in the apparatus, preferably, the second data obtaining module is further configured to:

the method comprises the steps of obtaining alkane series carbon isotope data at least comprising methane and ethane carbon isotope data in a natural gas sample in a research area, and judging whether the natural gas sample is coal-formed gas or not according to the alkane carbon isotope sequence and the methane and ethane carbon isotope data.

According to a specific embodiment of the present invention, in the apparatus, preferably, the first contribution ratio obtaining module is specifically configured to:

according to the average value of the alkane carbon isotope data with large coal gas isotope distribution range difference, the minimum end-member value of the alkane carbon isotope data with large research area coal-series mudstone thermal simulation gas carbon isotope distribution range difference and the maximum end-member value of the alkane carbon isotope data with large research area coal-series mudstone thermal simulation gas carbon isotope distribution range difference, the contribution rates of the coal-series coal rock and the mudstone in the coal gas of the research area are respectively obtained according to the following formula 1) and formula 2):

X＝(C_iaverage-C_{i coal series mudstone end member min})/(C_{i coal series coal rock end member max}-C_{i coal series mudstone end member min}) × 100% equation 1);

y ═ 100% -X formula 2);

in the formula 1) and the formula 2), X is the contribution rate of coal-series coal rocks in the coal gasification gas;

y is the contribution rate of coal-series mudstone in coal gasification;

C_iaveragethe average value of the alkane carbon isotope data with larger distribution range difference of the carbon isotopes of the coal gas is obtained;

C_{i coal series mudstone end member min}Simulating the minimum end-member value of alkane carbon isotope data with larger gas carbon isotope distribution range difference for the coal series mudstone thermal simulation of the research area;

C_{i coal series coal rock end member max}Simulating the maximum end-member value of the alkane carbon isotope data with large gas carbon isotope distribution range difference for the coal measure coal rock thermal simulation of the research area;

i is 1 or 2.

According to a specific embodiment of the present invention, the apparatus further includes a second contribution rate obtaining module, where the second contribution rate obtaining module is configured to:

when the minimum end-member value of the alkane carbon isotope data with large difference of the distribution range of the coal-series mudstone thermal simulation gas carbon isotopes in the research area and/or the maximum end-member value of the alkane carbon isotope data with large difference of the distribution range of the coal-series mudstone thermal simulation gas carbon isotopes in the research area cannot be obtained, the contribution rates of the coal-series coal rock and the mudstone in the coal-series mudstone in the research area are respectively obtained according to the average value of the alkane carbon isotope data with large difference of the distribution range of the coal-gas carbon isotopes, the minimum end-member value of the alkane carbon isotope data with large difference of the distribution range of the coal-gas carbon isotopes and/or the maximum end-member value of the alkane carbon isotope data with large difference of the distribution range of the coal-gas carbon isotopes.

According to a specific embodiment of the present invention, in the apparatus, preferably, the second contribution ratio obtaining module is specifically configured to:

according to the average value of the alkane carbon isotope data with the large coal gas carbon isotope distribution range difference, the minimum end member value of the alkane carbon isotope data with the large coal gas carbon isotope distribution range difference and/or the maximum end member value of the alkane carbon isotope data with the large coal gas carbon isotope distribution range difference, the contribution rates of coal series coal rocks and mudstones in the coal gas of the research area are respectively obtained according to the following formula 3) and formula 4):

X＝(C_iaverage-C_{i coal series mudstone end member min}Or C_imin)/(C_{i coal series coal rock end member max}Or C_imax-C_{i coal series mudstone end member min}Or C_imin) × 100% equation 3);

y ═ 100% to X formula 4);

in the formula 3) and the formula 4), X is the contribution rate of coal-series coal rocks in the coal gasification gas;

y is the contribution rate of coal-series mudstone in coal gasification;

C_iminthe minimum end-member value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference is obtained;

C_imaxfor the alkane carbon isotope data with larger distribution range difference of coal gas carbon isotopesThe maximum end-member value of;

C_iaveragethe average value of the alkane carbon isotope data with larger distribution range difference of the carbon isotopes of the coal gas is obtained;

C_{i coal series mudstone end member min}Simulating the minimum end-member value of alkane carbon isotope data with larger gas carbon isotope distribution range difference for the coal series mudstone thermal simulation of the research area;

C_{i coal series coal rock end member max}Simulating the maximum end-member value of the alkane carbon isotope data with large gas carbon isotope distribution range difference for the coal measure coal rock thermal simulation of the research area;

i is 1 or 2.

According to a specific embodiment of the present invention, the apparatus further includes a third data acquisition module, where the third data acquisition module is configured to:

according to the alkane carbon isotope distribution range with larger carbon isotope distribution range difference in the coal gas sample determined in the research area, the average value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference, the minimum end-member value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference and/or the maximum end-member value of the alkane carbon isotope data with larger coal gas carbon isotope distribution range difference are obtained.

In yet another aspect, the present invention further provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor implements the method for evaluating carbon isotopes in coal-based coal petrography and mudstone contribution rate in coal-forming gas when executing the computer program.

In still another aspect, the present invention further provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program for executing the method for evaluating carbon isotopes in coal-derived coal petrography and mudstone contribution rate in coal-derived gas.

The method for evaluating the carbon isotope contribution rate of the coal-series coal rock and the mudstone in the coal-forming gas is a quantitative evaluation method for the contribution rate of the coal-series coal rock and the mudstone in the coal-forming gas based on the alkane carbon isotope. The quantitative evaluation method provided by the invention can quickly, accurately and effectively quantitatively evaluate the coal rock and mudstone contributions of the coal source rock in the coal gas, and further can provide powerful technical support for deepening the research of natural gas origin and source and guiding the coal gas exploration.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

FIG. 1 is a flow chart of a method for evaluating carbon isotopes in coal-based coal petrography and mudstone contribution rate in coal-formed gas according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a carbon isotope evaluation device for coal-based coal rock and mudstone contribution rate in coal-formed gas according to an embodiment of the invention;

FIG. 3 is a graph of the determination of the cause of natural gas in a Kg deep gas field according to an embodiment of the present invention.

Detailed Description

In order to clearly understand the technical features, objects and advantages of the present invention, the following detailed description of the technical solutions of the present invention will be made with reference to the following specific examples, which should not be construed as limiting the implementable scope of the present invention.

Fig. 1 is a flowchart of a method for evaluating carbon isotopes in coal-based coal petrography and mudstone contribution rate in coal-formed gas in an embodiment of the present invention, as shown in fig. 1, the method includes:

step 101, acquiring a methane carbon isotope distribution range, an ethane carbon isotope distribution range, a methane carbon isotope distribution range difference and an ethane carbon isotope distribution range difference in a coal gas sample determined in a research area;

102, judging the size of the difference of the distribution range of the methane carbon isotopes and the size of the difference of the distribution range of the ethane carbon isotopes, and taking carbon isotope data of alkanes with larger difference of the distribution range of the carbon isotopes as parameters for evaluating the contribution rate of coal-series coal rocks and mudstone in the coal-forming gas;

103, respectively obtaining the contribution rates of the coal-series coal rock and the mudstone in the coal-series gas of the research area according to the average value of the alkane carbon isotope data with larger coal-series gas carbon isotope distribution range difference, the minimum end-member value of the alkane carbon isotope data with larger coal-series mudstone thermal simulation gas carbon isotope distribution range difference of the research area and the maximum end-member value of the alkane carbon isotope data with larger coal-series coal rock thermal simulation gas carbon isotope distribution range difference of the research area.

In one embodiment, before obtaining the range of distribution of the methane carbon isotope, the range of distribution of the ethane carbon isotope, and the difference of the range of distribution of the methane carbon isotope and the difference of the range of distribution of the ethane carbon isotope in the coal gas sample that have been determined in the research area, the method further includes:

and acquiring the data of alkane series carbon isotopes in the natural gas sample of the research area to judge whether the natural gas sample is coal-formed gas.

In an embodiment, the acquiring data of the alkane series carbon isotopes in the natural gas sample in the research area to determine whether the natural gas sample is coal-formed gas includes:

and acquiring alkane series carbon isotope data in a natural gas sample in a research area, and judging whether the natural gas sample is coal gas or not according to the alkane carbon isotope sequence, the methane carbon isotope data and the ethane carbon isotope data.