A method for constructing the average molecular structure of heavy oil heavy components

Abstract

This invention relates to the field of molecular simulation technology. It provides a method for constructing the average molecular structure of heavy oil heavy components, including inputting parameters, generating core aromatic ring units, constructing inner aliphatic ring units, constructing outer aliphatic ring units, generating side chain units, and storing and outputting structural information. Through a traversal algorithm, multiple molecular structures that satisfy experimental data are generated at once, conforming to the compositional characteristics of complex heavy oil mixtures. This provides more usable molecular structures for molecular simulation, improving the accuracy and efficiency of molecular modeling. It can quickly generate molecular structures that perfectly match experimental data, and only requires input from mass spectrometers, elemental analyzers, 1H NMR spectroscopy, and infrared spectroscopy data, reducing experimental costs.

Description

Technical Field

[0001] This invention relates to the field of molecular simulation technology, and in particular to a method for constructing the average molecular structure of heavy oil recombinant components. Background Technology

[0002] Molecular dynamics simulations have been widely used to study the microscopic aggregation characteristics and dynamic evolution of heavy oil systems, and constructing accurate molecular structures is a key prerequisite for conducting molecular simulation research. Asphaltenes, the largest and most polar component in heavy oil, are a crucial component for thickening. Asphaltenes molecules include structures composed of a single aromatic core and structures composed of multiple aromatic cores. Traditional methods for constructing average molecular structures cannot reflect the true carbon and hydrogen information of the molecule, do not consider the case with multiple aromatic cores, have limited molecular models, and do not account for the influence of heteroatoms, thus failing to obtain accurate average molecular structures and affecting the accuracy of molecular simulation results. Summary of the Invention

[0003] In view of this, the present invention aims to propose a method for constructing the average molecular structure of heavy oil heavy components. By combining algorithms and molecular simulation technology, and by writing algorithms and inputting experimental data, the corresponding average molecular structures of asphaltenes, including one aromatic core and multiple aromatic cores, can be constructed, laying the groundwork for further research on heavy oil.

[0004] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0005] A method for constructing the average molecular structure of heavy oil heavy components, the method comprising the following steps:

[0006] S1. Input parameters: Obtain experimental data of petroleum samples through experiments, including relative molecular mass, percentage content of each element, content of each type of H atoms, and convert them into the number of atoms of each element. Input the number of core aromatic ring units c.

[0007] S2. Generating Core Aromatic Ring Units: Based on the converted number of carbon atoms, each core aromatic ring unit is dynamically adjusted to generate different aromatic ring structures, including six-carbon, four-carbon, and three-carbon rings. This achieves automated construction of aromatic ring structures, outputs all matching aromatic ring combinations, and calculates the number of carbon and hydrogen atoms consumed for each combination, as well as the number of binding sites N of the core aromatic ring. f ;

[0008] S3. Constructing the inner aliphatic ring unit: A layer of directly connected aliphatic rings is generated around the core aromatic ring unit to filter out unreasonable structures and output the number of carbon atoms consumed and the number of different types of hydrogen atoms generated therefrom.

[0009] S4. Construct outer aliphatic ring units: Generate other aliphatic rings layer by layer outside the first aliphatic ring, filter out unreasonable structures, and output the number of carbon atoms consumed and the number of different types of hydrogen atoms generated.

[0010] S5. Generate side chain units: Generate side chains from the remaining carbon and hydrogen atoms according to the type of the remaining hydrogen atoms, determine the specific positions of their connections, and filter out unreasonable structures by using constraints to output reasonable structures.

[0011] S6. Storage and output of structural information: Automatically record, classify, store, and format molecular structures that meet the characteristic requirements.

[0012] Furthermore, the petroleum sample contains elements including C, H, O, N, and S. O atoms are considered to form carbon-oxygen single or double bonds, N atoms are considered to form six-membered or five-membered rings, and S atoms are considered to form five-membered rings or disulfide bonds; H includes H2... A H α H β H γ Numerical corrections were performed on different types of H atoms, when H γ If the number of atoms is not a multiple of 3, adjust it to the nearest multiple of 3, and the difference in the total number is determined by H. β make up.

[0013] Furthermore, the specific method for generating the core aromatic ring unit is as follows:

[0014] S21. Each core aromatic ring unit is first assigned one six-carbon ring;

[0015] S22. Next, four-carbon rings are formed first. If they are divisible by 4, all of them are formed. If there is 1 carbon atom remaining, 2 four-carbon rings are reduced and 3 three-carbon rings are added. If there are 2 carbon atoms remaining, 1 four-carbon ring is reduced and 2 three-carbon rings are added. If there are 3 carbon atoms remaining, 1 three-carbon ring is added directly to ensure that all carbon atoms used to form the core aromatic ring can form a complete aromatic ring.

[0016] S23. Based on experimental data, use heteroatoms to replace carbon atoms to form N-containing five-membered rings, N-containing six-membered rings, or S-containing five-membered rings.

[0017] S24. With the number of carbon atoms remaining constant, every 3 four-carbon rings can be converted into 4 three-carbon rings, thereby generating different combinations of aromatic rings and outputting different reasonable structures.

[0018] Furthermore, the generated core aromatic ring unit satisfies the following condition:

[0019] I. The number of aromatic carbons does not exceed 1 / 2 of the total number of carbon atoms, nor does it exceed twice the number of H atoms. A With H α The sum of quantities;

[0020] II. Each core has at least one aromatic ring, that is, each core has at least one six-carbon ring;

[0021] III. Within the same core, if there is already a six-carbon ring, constructing a second aromatic ring requires four carbon atoms, thus generating a four-carbon ring. When constructing a third aromatic ring, four carbon atoms can be added to form a four-carbon ring, or three carbon atoms can be added to form a three-carbon ring. However, if the six-carbon ring and the four-carbon ring are not fully constructed, a three-carbon ring cannot be directly constructed. A six-carbon ring cannot be directly connected to a three-carbon ring.

[0022] VI. Based on the above conditions, the number of aromatic carbons cannot be 1, 2, 3, 4, 5, 7, 8, 9, 11, 12, or 15.

[0023] Furthermore, the number of binding sites N f The calculation method is as follows: each six-carbon ring has 6 sites; when a four-carbon ring is connected, 2 sites are consumed and 4 sites are added; when a three-carbon ring is connected, 2 sites are consumed and 3 sites are added. The final total is N. f =6×N AR6 +(4-2)×N AR4 +(3-2)×N AR3 N AR6 The number of six-carbon rings, N AR4 The number of four carbon rings, N AR3 The number of tricarbon rings.

[0024] The binding site is the location around the aromatic carbon where a carbon atom / hydrogen atom can be attached, or where an aromatic ring / aliphatic ring can be attached.

[0025] Furthermore, the specific method for constructing the inner aliphatic ring unit is as follows: on the periphery of the generated core aromatic ring unit, carbon atoms are used to replace H atoms at two adjacent binding sites, and one or two carbon atoms are added between the two adjacent binding sites to form an aliphatic ring structure.

[0026] Furthermore, it satisfies: 0≤r1≤N f ;

[0027] 0 ≤ t1 ≤ r1, and t1 ≤ N f -r1;

[0028] 0≤m1≤r1, m1≤6c, and m1≤6t1;

[0029] Where r1 is the number of aliphatic rings in the inner aliphatic ring unit; t1 is the number of breakpoints, that is, the number of segments of aliphatic rings formed in the first aliphatic ring structure generated around the central aromatic ring; m1 is the number of multipoints, that is, the number of times two more carbon atoms are added between two binding sites around the central aromatic ring to form one aliphatic ring structure.

[0030] Furthermore, the constructed inner adipose ring unit satisfies the following conditions:

[0031] When r1<1 / 3·N f When m1 ≤ 2c;

[0032] When 1 / 3·N f ≤r1<1 / 2·N f When 2c≤m1≤3c;

[0033] When 1 / 2·N f ≤r1<2 / 3·N f When 3c≤m1≤4c;

[0034] When r1≥2 / 3·N f When m1 ≥ 4c;

[0035] When r1=N f At that time, m1 = 6c;

[0036] When 0 <r1<N f When t1 ≠ 0;

[0037] When r1=0, t1=m1=0;

[0038] When t1≠0, N f / c≥r1 / t1;

[0039] When N f When r = 6c, r1 = m1.

[0040] There are three possibilities for the formation of an aliphatic ring between two sites: no carbon atom needs to be added, one carbon atom needs to be added, or two carbon atoms need to be added. Generally, the second possibility is the most likely. The first and third possibilities can be neutralized into the second, so we only consider the case of adding two carbon atoms. Furthermore, if aliphatic rings are added to all sites, after neutralization, the m1 of all aromatic cores will be 6, meaning the maximum m1 for each aromatic core is 6.

[0041] Furthermore, the calculation methods for the number of carbon atoms and the number of hydrogen atoms of different types in the constructed inner aliphatic ring unit are as follows:

[0042] Number of carbon atoms N C1 =2r1+t1+m1;

[0043] H A Number N HA =N f -r1-t1;

[0044] H α Number N Hα =r1+3t1;

[0045] H β Number N Hβ1 =2r1+2m1.

[0046] Furthermore, the outer adipose ring unit comprises n layers of adipose ring structures, where n ≥ 1 and n is an integer. The inner adipose ring unit is designated as the first layer of adipose ring structure, and the adipose ring structures in the outer adipose ring unit are counted starting from the second layer. Then, for the i-th layer of adipose ring structure in the outer adipose ring unit, 2 ≤ i ≤ n + 1, the following condition is satisfied:

[0047] 0≤r i ≤r i-1 And 0≤t i ≤r i ,0≤m i ≤m i-1 And m i ≤r i ; where r i t represents the number of fatty rings in the i-th layer of fatty ring structure; i The number of breakpoints, i.e., the number of segments of the fatty ring formed in the i-th layer of the fatty ring structure; m i The number of times a multi-point number is formed is the number of times two carbon atoms are added between two binding sites around the previous layer of aliphatic ring structure to form one aliphatic ring structure in this layer.

[0048] And, when r i =r i-1 At that time, t i =t i-1 m i =m i-1 , and m i-1 ≥t i-1 ;

[0049] When r i When = 0, m i =0;

[0050] When r i When t ≠ 0, i ≠0;

[0051] When r i-1 -t i-1 <r i <r i-1 hour:

[0052] ①r i -(r i-1 -t i-1 )≤mi and t i ≤t i-1 ;

[0053] ②r i-1≥2t i-1 At that time, t i =t i-1 ;

[0054] ③r i-1 <2t i-1 At that time, t i ≥r i-1 -t i-1 And t i-1 -t i ≤r i-1 -r i ;

[0055] When r i ≤r i-1 -t i-1 At that time, t i +r i ≤r i-1 .

[0056] Furthermore, the calculation method for the number of carbon atoms and the number of hydrogen atoms of different types in the i-th layer aliphatic ring structure of the constructed outer aliphatic ring unit is as follows:

[0057] Number of carbon atoms N Ci =2r i +t i +m i ;

[0058] H β Number N Hβi =2r i +2t i +2m i .

[0059] Furthermore, the specific method for generating sidechains is as follows: all H γ All form methyl groups at the ends of the carbon chains, that is, every 3 H atoms γ The side chain is attached to a single carbon atom; the remaining carbon atoms forming the carbon chain should be greater than the number of terminal methyl groups and the number of carbon chains attached to the aromatic core; if the side chain is not attached to the aromatic ring, then all rings will generate H... A and H α All conditions are met according to experimental data, and the carbon-to-hydrogen ratio in the remaining atoms forming the carbon chain is equal to 1 / 2; if the side chain is attached to the aromatic ring, then all the H atoms on the aromatic ring... α and H A The quantity and H of experimental data α and H A The ratio ΔN of the difference in quantity Hα / ΔN HA=-2, after removing the methyl group at the end of the carbon chain, the carbon-hydrogen ratio in all atoms forming the carbon chain should be equal to 1 / 2; finally, based on experimental data, heteroatom structures located on the carbon chain are added, including disulfide bonds, carbon-oxygen double bonds, and carbon-oxygen single bonds.

[0060] Compared with existing technologies, the method for constructing the average molecular structure of heavy oil heavy components described in this invention has the following advantages:

[0061] (1) The method for constructing the average molecular structure of heavy oil heavy components described in this invention considers as many heteroatom types as possible, covers more possible structures of heavy oil heavy components, and is the first to generate asphaltenes molecules with multiple aromatic cores through nuclear magnetic resonance hydrogen spectrum data.

[0062] (2) The method for constructing the average molecular structure of heavy oil components described in this invention generates multiple molecular structures that meet the experimental data at one time through the traversal algorithm, which conforms to the composition characteristics of complex mixtures of heavy oil and provides more usable molecular structures for molecular simulation.

[0063] (3) The method for constructing the average molecular structure of heavy oil components described in this invention improves the accuracy and efficiency of molecular modeling, can quickly generate molecular structures that fully conform to experimental data, and only requires input of mass spectrometer, elemental analyzer, nuclear magnetic resonance hydrogen spectrum and infrared spectrum data, thus reducing experimental costs. Attached Figure Description

[0064] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0065] Figure 1 This is a diagram illustrating the breakpoint;

[0066] Figure 2 This is a multi-point diagram;

[0067] Figure 3 The following are partial structures of Example 1: (a) is structure numbered 1, (b) is structure numbered 2, (c) is structure numbered 12, (d) is structure numbered 13, (e) is structure numbered 32, and (f) is structure numbered 33.

[0068] Figure 4 The following are partial structures of Example 2: (a) is structure numbered 1, (b) is structure numbered 2, (c) is structure numbered 16, (d) is structure numbered 17, (e) is structure numbered 27, and (f) is structure numbered 29.

[0069] Figure 5The following are partial structures of Example 3: (a) is structure number 1, (b) is structure number 2, (c) is structure number 14, and (d) is structure number 15. Detailed Implementation

[0070] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0071] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0072] Example 1

[0073] A method for constructing the average molecular structure of heavy oil heavy components, the method comprising the following steps:

[0074] S1, Input parameters:

[0075] A sample of Shengli Zheng 364-XN363 oil was used as the sample, and experimental data of the petroleum sample were obtained through experiments.

[0076] The relative molecular mass distribution and mean relative molecular mass of heavy oil gums and asphaltenes were determined by GPC. The instrument used in the experiment was a HELEOS System gel chromatograph from Wyatt, USA. The chromatographic column was an Agilent plgel 10μm column. The column temperature was 40℃, the mobile phase was tetrahydrofuran (THF), and the mobile phase rate was 1.0 mL / min. The results are as follows.

[0077] Table 1 Sample Test Data

[0078]

[0079] The quantitative nuclear magnetic resonance spectra of heavy oil and its resins and asphaltenes were determined using a Bruker 600M ADVAN liquid nuclear magnetic resonance spectrometer. 1 (H NMR), with CDCL3 as solvent, the results are as follows.

[0080] Table 2 Mass fraction of different types of hydrogen

[0081]

[0082] The elemental contents of C, H, S, and N in heavy oil resins and asphaltenes were determined using a Vario EL CHSN elemental analyzer from Elementar (Germany). The O element content was calculated using the difference method, and the results are as follows.

[0083] Table 3. Mass fraction (%) of different elements

[0084]

[0085] Based on the above data, the content of each element is shown in the table below.

[0086] Table 4 Mass fraction of each element

[0087]

[0088] Based on Table 4, the molecular formula is C4, calculated to have the number of atoms for each element. 64 H 84 O2N1, the number of H atoms of different types are as follows: H A 5, H α 13, H β 51, H γ 15.

[0089] Input the number of core aromatic ring units c=1.

[0090] S2. Generating Core Aromatic Ring Units: Based on the converted number of carbon atoms, each core aromatic ring unit is dynamically adjusted to generate different aromatic ring structures, including six-carbon ring AR6, four-carbon ring AR4, and three-carbon ring AR3. This achieves automated construction of aromatic ring structures, outputs all matching aromatic ring combinations, and calculates the number of carbon and hydrogen atoms consumed for each combination, as well as the number of binding sites N of the core aromatic ring. f ;

[0091] The specific method is as follows:

[0092] S21, the core aromatic ring unit is first assigned one six-carbon ring;

[0093] S22. Next, four-carbon rings are formed first. If they are divisible by 4, all four-carbon rings are formed. If there is 1 carbon atom remaining, 2 four-carbon rings are reduced and 3 three-carbon rings are added. If there are 2 carbon atoms remaining, 1 four-carbon ring is reduced and 2 three-carbon rings are added. If there are 3 carbon atoms remaining, 1 three-carbon ring is added directly, ensuring that all carbon atoms used to form the core aromatic ring can form a complete aromatic ring. For example, the composition of aromatic ring numbered 1 in Table 5 is [6,4,4,4,3].

[0094] S23. Based on experimental data, use heteroatoms to replace carbon atoms to form N-containing five-membered rings, N-containing six-membered rings, or S-containing five-membered rings.

[0095] S24. With the number of carbon atoms remaining constant, every 3 four-carbon rings can be converted into 4 three-carbon rings, thereby generating different combinations of aromatic rings and outputting different reasonable structures.

[0096] The generated core aromatic ring unit satisfies the following conditions:

[0097] I. The number of aromatic carbons does not exceed 1 / 2 of the total number of carbon atoms, nor does it exceed twice the number of H atoms. A With H α The sum of quantities;

[0098] II. Each core has at least one aromatic ring, that is, each core has at least one six-carbon ring;

[0099] III. Within the same core, if there is already a six-carbon ring, constructing a second aromatic ring requires four carbon atoms, thus generating a four-carbon ring. When constructing a third aromatic ring, four carbon atoms can be added to form a four-carbon ring, or three carbon atoms can be added to form a three-carbon ring. However, if the six-carbon ring and the four-carbon ring are not completed, a three-carbon ring cannot be directly constructed. The six-carbon ring AR6 cannot be directly connected to the three-carbon ring AR3.

[0100] VI. Based on the above conditions, the number of aromatic carbons cannot be 1, 2, 3, 4, 5, 7, 8, 9, 11, 12, or 15.

[0101] Number of binding sites N f The calculation method is as follows:

[0102] Each six-carbon ring has 6 sites. Connecting a four-carbon ring consumes 2 sites and adds 4 sites. Connecting a three-carbon ring consumes 2 sites and adds 3 sites, resulting in a total of N. f =6×N AR6 +(4-2)×N AR4 +(3-2)×N AR3 N AR6 The number of six-carbon rings, N AR4 The number of four carbon rings, N AR3 The number of tricarbon rings.

[0103] S3. Constructing the inner aliphatic ring unit: A layer of directly connected aliphatic rings is generated around the core aromatic ring unit as the first aliphatic ring structure. There are three possibilities for the formation of an aliphatic ring between two adjacent binding sites on the core aromatic ring unit: no carbon atom is needed, one carbon atom is added, and two carbon atoms are added. In general, the second possibility is the most likely. The first and third possibilities can be neutralized into the second possibility, that is, adding two carbon atoms to form an aliphatic ring structure.

[0104] Furthermore, it satisfies: 0≤r1≤N f ;

[0105] 0 ≤ t1 ≤ r1, and t1 ≤ N f -r1;

[0106] 0≤m1≤r1, m1≤6c, and m1≤6t1;

[0107] Where r1 is the number of fatty rings in the inner fatty ring unit; t1 is the number of breakpoints, that is, the number of segments of fatty rings formed in the first layer of fatty ring structure generated around the central aromatic ring, such as... Figure 1 As shown, three aliphatic ring segments (red, yellow, and blue) are formed around the central aromatic ring unit, i.e., t1=3; m1 is the number of points, i.e., the number of times two carbon atoms need to be added between the two binding sites around the central aromatic ring to form one aliphatic ring structure, such as... Figure 2 As shown, the binding sites around the central aromatic carbon are red. Adding two carbon atoms (blue) between these binding sites to form an aromatic ring structure is considered one iteration, referred to as a multi-site structure. Figure 2 In the middle, m1=3.

[0108] Filter out unreasonable structures according to the following conditions:

[0109] When r1<1 / 3·N f When m1 ≤ 2c;

[0110] When 1 / 3·N f ≤r1<1 / 2·N f When 2c≤m1≤3c;

[0111] When 1 / 2·N f ≤r1<2 / 3·N f When 3c≤m1≤4c;

[0112] When r1≥2 / 3·N f When m1 ≥ 4c;

[0113] When r1=·N f At that time, m1 = 6c;

[0114] When 0 <r1<N f When t1 ≠ 0;

[0115] When r1=0, t1=m1=0;

[0116] When t1≠0, N f / c≥r1 / t1.

[0117] By applying the above rules, 98% of unreasonable structures can be filtered out.

[0118] Calculate the number of carbon atoms consumed and the number of hydrogen atoms of different types generated as a result:

[0119] Number of carbon atoms N C1 = 2r1 + t1 + m1;

[0120] H A Number N HA = N f - r1 - t1;

[0121] H α Number N Hα = r1 + 3t1;

[0122] Number of Hβ Hβ1 = 2r1 + 2m1.

[0123] S4. Construct the outer aliphatic ring unit: Generate other layers of aliphatic rings layer by layer outside the first layer of aliphatic rings.

[0124] Construct the second layer of aliphatic ring structure:

[0125] 0 ≤ r2 ≤ r1 and 0 ≤ t2 ≤ r2, 0 ≤ m2 ≤ m1 and m2 ≤ r2; where, r2 is the number of aliphatic rings in the second layer of aliphatic ring structure; t2 is the number of break points, that is, the number of segments of the aliphatic rings formed in the second layer of aliphatic ring structure generated around the inner aliphatic ring unit (the first layer of aliphatic ring structure); m2 is the number of multi-points, that is, the number of times of adding 2 carbon atoms between two binding sites around the inner aliphatic ring unit to form 1 aliphatic ring structure.

[0126] Filter out unreasonable structures according to the following conditions:

[0127] When r2 = r1, t2 = t1, m2 = m1, and m1 > t1;

[0128] When r2 = 0, m2 = 0;

[0129] When r2 ≠ 0, t2 ≠ 0;

[0130] When r1 - t1 < r2 < r1:

[0131] ① r2 - (r1 - t1) ≤ m2 and t2 ≤ t1;

[0132] ② When r1 ≥ 2t1, t2 = t1;

[0133] ③ When r1 < 2t1, t2 ≥ r1 - t1 and t1 - t2 ≤ r1 - r2;

[0134] When r2 ≤ r1 - t1, t2 + r2 ≤ r1.

[0135] After being constrained by the above rules, 98% of the unreasonable structures can be filtered out.

[0136] Calculate and output the consumed number of carbon atoms and the number of different types of hydrogen atoms generated therefrom:

[0137] Number of carbon atoms N C2 =2r² + t² + m²;

[0138] H β Number N Hβ2 =2r² + 2t² + 2m².

[0139] The method for producing the third adipose ring structure is the same as above.

[0140] S5. Generate side chain units: Generate side chains from the remaining carbon and hydrogen atoms according to the type of the remaining hydrogen atoms, determine the specific positions of their connections, and filter out unreasonable structures by using constraints to output reasonable structures.

[0141] The specific requirements are as follows:

[0142] Ⅰ. All H γ All form methyl groups at the ends of the carbon chains, that is, every 3 H atoms γ It is attached to a carbon atom;

[0143] II. The remaining carbon atoms forming the carbon chain should be greater than the number of terminal methyl groups and the number of carbon chains connecting the aromatic nucleus;

[0144] III. If the side chain is not attached to the aromatic ring, then all rings will generate H A and H α All meet the experimental data, and the carbon-hydrogen ratio in the remaining atoms forming the carbon chain is equal to 1 / 2;

[0145] VI. If the side chain is attached to the aromatic ring, then all H on the aromatic ring... α and H A The quantity and H of experimental data α and H A The ratio ΔN of the difference in quantity Hα / ΔN HA =-2, after removing the methyl group at the end of the carbon chain, the carbon-hydrogen ratio of all atoms forming the carbon chain should be equal to 1 / 2;

[0146] Where, ΔN HA =N HA-实验 -N HA-芳香环 ΔN Hα =N Hα-实验 -N Hα-芳香环 .

[0147] V. Finally, based on the experimental data, heteroatom structures located on the carbon chain are added, including disulfide bonds, carbon-oxygen double bonds, and carbon-oxygen single bonds.

[0148] By applying the above rules, 98% of unreasonable structures can be filtered out.

[0149] S6. Storage and output of structural information: Automatically record, classify, store, and format molecular structures that meet the characteristic requirements.

[0150] When the number of core aromatic ring units c=1, there are a total of 43 structures, as shown in the table below.

[0151] Table 5. Statistics of molecular structures meeting the characteristic requirements when c=1.

[0152]

[0153] Figure 3 Six of the structures are given: structure number 1, structure number 2, structure number 12, structure number 13, structure number 32, and structure number 33.

[0154] Example 2

[0155] S1, Input parameters:

[0156] Similar to Example 1, the Shengli Zheng 364-XN363 oil sample was used as the sample, and the experimental parameters were the same as in Example 1, with the number of core aromatic ring units c=2.

[0157] S2-S6 are the same as in Example 1.

[0158] When the number of core aromatic ring units c=2, there are a total of 309 structures. The following table shows 45 examples of these structures.

[0159] Table 6. Statistics of molecular structures meeting the characteristic requirements when c=2.

[0160]

[0161] Figure 4 Six of the structures are given: structure number 1, structure number 2, structure number 16, structure number 17, structure number 27, and structure number 29.

[0162] Example 3

[0163] S1, Input parameters:

[0164] Similar to Example 1, the Shengli Zheng 364-XN363 oil sample was used as the sample, and the experimental parameters were the same as in Example 1, with the number of core aromatic ring units c=3.

[0165] S2-S6 are the same as in Example 1.

[0166] When the number of core aromatic ring units c=3, there are a total of 179 structures. The following table shows 24 examples of these structures.

[0167] Table 7. Statistics of molecular structures meeting the characteristic requirements when c=3.

[0168]

[0169] The method of this invention generates multiple molecular structures that meet the experimental data at once through a traversal algorithm, which conforms to the compositional characteristics of complex mixtures of heavy oil. This provides more usable molecular structures for molecular simulation, improves the accuracy and efficiency of molecular modeling, and can quickly generate molecular structures that fully conform to the experimental data. Furthermore, it only requires input from mass spectrometers, elemental analyzers, proton nuclear magnetic resonance spectra, and infrared spectra, thus reducing experimental costs.

[0170] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for constructing the average molecular structure of heavy oil heavy components, characterized in that, The method includes the following steps: S1. Input parameters: Obtain experimental data of petroleum samples through experiments, including relative molecular mass, percentage content of each element, content of each type of H atoms, and convert them into the number of atoms of each element. Input the number of core aromatic ring units c. S2. Generating Core Aromatic Ring Units: Based on the converted number of carbon atoms, each core aromatic ring unit is dynamically adjusted to generate different aromatic ring structures, including six-carbon, four-carbon, and three-carbon rings. This achieves automated construction of aromatic ring structures, outputs all matching aromatic ring combinations, and calculates the number of carbon and hydrogen atoms consumed for each combination, as well as the number of binding sites N of the core aromatic ring. f ; S3. Constructing the inner aliphatic ring unit: A layer of directly connected aliphatic rings is generated around the core aromatic ring unit to filter out unreasonable structures and output the number of carbon atoms consumed and the number of different types of hydrogen atoms generated therefrom. S4. Construct outer aliphatic ring units: Generate other aliphatic rings layer by layer outside the first aliphatic ring, filter out unreasonable structures, and output the number of carbon atoms consumed and the number of different types of hydrogen atoms generated. S5. Generate side chain units: Generate side chains from the remaining carbon and hydrogen atoms according to the type of the remaining hydrogen atoms, determine the specific positions of their connections, and filter out unreasonable structures by using constraints to output reasonable structures. S6. Storage and output of structural information: Automatically record, classify, store, and format molecular structures that meet the characteristic requirements.

2. The method for constructing the average molecular structure of heavy oil heavy components according to claim 1, characterized in that, The specific method for generating the core aromatic ring unit is as follows: S21. Each core aromatic ring unit is first assigned one six-carbon ring; S22. Next, four-carbon rings are formed first. If they are divisible by 4, all of them are formed. If there is 1 carbon atom remaining, 2 four-carbon rings are reduced and 3 three-carbon rings are added. If there are 2 carbon atoms remaining, 1 four-carbon ring is reduced and 2 three-carbon rings are added. If there are 3 carbon atoms remaining, 1 three-carbon ring is added directly to ensure that all carbon atoms used to form the core aromatic ring can form a complete aromatic ring. S23. Based on experimental data, use heteroatoms to replace carbon atoms to form N-containing five-membered rings, N-containing six-membered rings, or S-containing five-membered rings. S24. With the number of carbon atoms remaining constant, every 3 four-carbon rings can be converted into 4 three-carbon rings, thereby generating different combinations of aromatic rings and outputting different reasonable structures.

3. The method for constructing the average molecular structure of heavy oil heavy components according to any one of claims 1-2, characterized in that, The generated core aromatic ring unit satisfies the following conditions: I. The number of aromatic carbons does not exceed 1 / 2 of the total number of carbon atoms, nor does it exceed twice the number of H atoms. A With H α The sum of quantities; II. Each core has at least one aromatic ring, that is, each core has at least one six-carbon ring; III. Within the same core, if there is already a six-carbon ring, constructing a second aromatic ring requires four carbon atoms, thus generating a four-carbon ring. When constructing a third aromatic ring, four carbon atoms can be added to form a four-carbon ring, or three carbon atoms can be added to form a three-carbon ring. However, if the six-carbon ring and the four-carbon ring are not fully constructed, a three-carbon ring cannot be directly constructed. A six-carbon ring cannot be directly connected to a three-carbon ring. VI. Based on the above conditions, the number of aromatic carbons cannot be 1, 2, 3, 4, 5, 7, 8, 9, 11, 12, or 15.

4. The method for constructing the average molecular structure of heavy oil heavy components according to any one of claims 1-2, characterized in that, Number of binding sites N f The calculation method is as follows: each six-carbon ring has 6 sites; when a four-carbon ring is connected, 2 sites are consumed and 4 sites are added; when a three-carbon ring is connected, 2 sites are consumed and 3 sites are added. The final total is N. f =6×N AR6 +(4-2)×N AR4 +(3-2)×N AR3 N AR6 The number of six-carbon rings, N AR4 The number of four carbon rings, N AR3 The number of tricarbon rings.

5. The method for constructing the average molecular structure of heavy oil heavy components according to claim 1, characterized in that, The specific method for constructing the inner aliphatic ring unit is as follows: on the periphery of the generated core aromatic ring unit, carbon atoms replace H atoms at two adjacent binding sites, and one or two carbon atoms are added between the two adjacent binding sites to form an aliphatic ring structure. Furthermore, it satisfies: 0≤r1≤N f ; 0 ≤ t1 ≤ r1, and t1 ≤ N f -r1; 0≤m1≤r1, m1≤6c, and m1≤6t1; Where r1 is the number of aliphatic rings in the inner aliphatic ring unit; t1 is the number of breakpoints, that is, the number of segments of aliphatic rings formed in the first aliphatic ring structure generated around the central aromatic ring; m1 is the number of multipoints, that is, the number of times two more carbon atoms are added between two binding sites around the central aromatic ring to form one aliphatic ring structure.

6. The method for constructing the average molecular structure of heavy oil heavy components according to claim 5, characterized in that, The constructed inner adipose ring unit satisfies the following conditions: When r1<1 / 3·N f When m1 ≤ 2c; When 1 / 3·N f ≤r1<1 / 2·N f When 2c≤m1≤3c; When 1 / 2·N f ≤r1<2 / 3·N f When 3c≤m1≤4c; When r1≥2 / 3·N f When m1 ≥ 4c; When r1=N f At that time, m1 = 6c; When 0 <r1<N f When t1 ≠ 0; When r1=0, t1=m1=0; When t1≠0, N f / c≥r1 / t1; When N f When r = 6c, r1 = m1.

7. The method for constructing the average molecular structure of heavy oil heavy components according to claim 5, characterized in that, The calculation methods for the number of carbon atoms and the number of hydrogen atoms of different types in the constructed inner aliphatic ring unit are as follows: Number of carbon atoms N C1 =2r1+t1+m1; H A number N HA = N f - r1 - t1; H α Number N Hα =r1+3t1; H β Number N Hβ1 =2r1+2m1.

8. The method for constructing the average molecular structure of heavy oil heavy components according to claim 1, characterized in that, The outer adipose ring unit consists of n layers of adipose ring structures, where n ≥ 1 and n is an integer. The inner adipose ring unit is designated as the first layer of adipose ring structure. The adipose ring structures in the outer adipose ring unit are counted starting from the second layer. Then, for the i-th layer of adipose ring structure in the outer adipose ring unit, 2 ≤ i ≤ n + 1, the following condition is satisfied: 0≤r i ≤r i-1 And 0≤t i ≤r i ,0≤m i ≤m i-1 And m i ≤r i ; where r i t represents the number of fatty rings in the i-th layer of fatty ring structure; i The number of breakpoints, i.e., the number of segments of the fatty ring formed in the i-th layer of the fatty ring structure; m i The number of times a multi-point number is formed is the number of times two carbon atoms are added between two binding sites around the previous layer of aliphatic ring structure to form one aliphatic ring structure in this layer. And, when r i =r i-1 At that time, t i =t i-1 m i =m i-1 And m i-1 ≥t i-1 ; When r i When = 0, m i =0; When r i When t ≠ 0, i ≠0; When r i-1 -t i-1 <r i <r i-1 hour: ①r i -(r i-1 -t i-1 )≤m i And t i ≤t i-1 ; ②r i-1 ≥2t i-1 At that time, t i =t i-1 ; ③r i-1 <2t i-1 At that time, t i ≥r i-1 -t i-1 And t i-1 -t i ≤r i-1 -r i ; When r i ≤r i-1 -t i-1 At that time, t i +r i ≤r i-1 .

9. The method for constructing the average molecular structure of heavy oil heavy components according to claim 8, characterized in that, The calculation method for the number of carbon atoms and the number of hydrogen atoms of different types in the i-th layer aliphatic ring structure in the constructed outer aliphatic ring unit is as follows: Number of carbon atoms N Ci =2r i +t i +m i ; H β Number N Hβi =2r i +2t i +2m i .

10. The method for constructing the average molecular structure of heavy oil heavy components according to claim 1, characterized in that, The specific method for generating sidechains is as follows: all H γ All form methyl groups at the ends of the carbon chains, that is, every 3 H atoms γ The side chain is attached to a single carbon atom; the remaining carbon atoms forming the carbon chain should be greater than the number of terminal methyl groups and the number of carbon chains attached to the aromatic core; if the side chain is not attached to the aromatic ring, then all rings will generate H... A and H α All must meet the experimental data, and the carbon-to-hydrogen ratio in the remaining atoms forming the carbon chain must be equal to 1 / 2; if the side chain is attached to the aromatic ring, then all H atoms on the aromatic ring must be... α and H A The quantity and H of experimental data α and H A The ratio ΔN of the difference in quantity Hα / ΔN HA =-2, after removing the methyl group at the end of the carbon chain, the carbon-hydrogen ratio in all atoms forming the carbon chain should be equal to 1 / 2; finally, based on experimental data, heteroatom structures located on the carbon chain are added, including disulfide bonds, carbon-oxygen double bonds, and carbon-oxygen single bonds.

Images