Method for determining maturity of solid bitumen with very high thermal evolution degree

Abstract

The application discloses a method for determining maturity of solid bitumen with extremely high thermal evolution degree and relates to the field of oil and gas geochemistry. The method comprises the following steps: separating soluble organic matter components in the solid bitumen to be measured to obtain saturated hydrocarbons, and detecting conventional maturity biomarkers in the saturated hydrocarbon components to determine whether the conventional maturity biomarkers are invalid or reversed; if the conventional maturity biomarkers are invalid, it indicates that the solid bitumen is over-mature, and the next step is performed; detecting whether the saturated hydrocarbon components contain 1,1,3-trimethyl-2-alkylcyclohexane series compounds to determine whether beta-carotane in the organic matter of the solid bitumen has undergone thermal evolution; determining absolute contents of the beta-carotane and the costane in the organic matter of the solid bitumen after thermal evolution, and calculating a ratio; and calculating the maturity of the organic matter: Ro=0.52lnX+3.3469; wherein, X is the ratio of the absolute contents of the costane and the beta-carotane. The application detects the costane and the beta-carotane, and provides valuable insights for evaluation of other highly thermally evolved hydrocarbons and related exploration work.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas geochemistry, and particularly relates to a method for determining maturity of solid bitumen with extremely high thermal evolution degree. BACKGROUND

[0002] The determination of the evolution process of organic matter largely depends on the maturity parameter. In the lower Paleozoic and older marine strata, the main source of oil is low algae and bacteria, rather than vitrinite particles from higher plants. This distinction poses a challenge to the determination of maturity. Bitumen reflectance (Ro) is usually used to evaluate the maturity of organic matter (OM) in ancient strata, and when comparing migrated pyrolytic solid bitumen found in ancient reservoirs with residual bitumen particles present in source rocks, various measurement techniques used to evaluate Ro can produce different results. In addition, due to differences in methods, researchers' analysis of Ro can have inherent errors. In addition, in solid bitumen exhibiting extremely high maturity or affected by abnormal thermal events, Ro values show significant variability, and no unified standard has been formed so far.

[0003] Molecular markers of organic matter play a crucial role in understanding its origin and evolution process, however, it has been a challenge to evaluate high evolution maturity of organic matter using molecular markers. Gas chromatography-mass spectrometry is a key technology for studying the molecular composition of crude oil. For immature organic matter, carbon preference index (CPI) or odd-even preference (OEP) can be used to distinguish the maturity of organic matter. These ratios show good adaptability during the maturation process of immature source rocks, however, once oil is formed, these indicators can no longer effectively determine the maturity of oil. Pristane (Pr) and phytane (Ph) are also used as maturity indicators, but they are more commonly used to distinguish depositional environments, especially the chart proposed by Volkman (1988). Ts and Tm represent a class of tricyclic terpenoid biomarkers derived from hopanoids, these configurations are produced by the transformation of unstable biological ββ configuration to more stable βα and αβ geological configurations. At the late stage of over-maturation, when Ro exceeds 1.3, convergence may occur, making it difficult to make a clear judgment, and dibenzothiophene (DBT) and its alkylated derivatives are important organosulfur compounds, which exist in sediments, coal and crude oil.

[0004] The stability of different isomers with different thermal stabilities is often used to synthesize compounds related to maturity indicators, such as 4-MDBT / 1-DMBT. There are certain limitations in using DBT series compounds to evaluate maturity. Compounds in the DBT series are not only affected by thermal degradation, but also by other factors. In carbonate rocks, the main thermochemical sulfate reduction (TSR) effect will cause changes in various potential organic sulfur compounds, thereby challenging analysis. The PHN series (PHN) is widely used as a thermal maturity indicator, and different indicators are selected according to the hydrocarbon source and maturity. Due to the difference in the content of substituents in different kerogens, 1-8 methylphenanthrene (1-MP) is commonly found in type II-I kerogens, which are characterized by a higher content of MP. PHN is chemically stable and not easily biodegraded, so it is often used to evaluate the degree of biodegradation. Similar to DBT, the PHN series exhibits similar behavior of substituted MP compounds in highly mature organic matter, resulting in ineffective indicators. Recently, diamondoid (DMD) compounds have been found to be useful in evaluating maturity levels. The cage-like molecular structure of DMD has been identified as an important indicator for evaluating oil cracking, and DMD exists in a maturity range of Ro 1.0-2.7. Certain isomerization parameters of DMD, including the methyl diamondoid index (MAI), the dimethyl diamondoid index (DMAI)-1, DMAI-2, the trimethyl diamondoid index (TMAI)-1, and TMAI-2, have significant correlations with the maturity levels of highly cracked crude oil. After excluding diagenetic DMD, the presence of DMD in crude oil indicates that the crude oil has entered the mature stage. However, for DMD, attention needs to be paid to the uncertainty caused by hydrocarbon volatilization during separation and detection.

[0005] In recent years, many researchers have attempted to use ROCK-Eval parameters to evaluate the maturity of highly evolved organic matter, using parameters such as maximum hydrocarbon content temperature (Tmax) and hydrogen index (HI) to calculate Ro values equivalently. However, this method is limited when dealing with solid bitumen containing a large amount of inert carbon. On the one hand, the Tmax value may exceed the detection limit due to its high magnitude; on the other hand, the HI value is often low due to the late evolution stage, resulting in ineffective indicators.

[0006] Therefore, finding a simple and effective method to evaluate the maturity of highly evolved organic matter is a problem that needs to be solved by the present application. SUMMARY

[0007] The present application provides a method for determining the maturity of solid bitumen with extremely high thermal evolution, which aims to solve the problems in the above background art.

[0008] In order to achieve the above technical purposes, the present application mainly adopts the following technical solutions:

[0009] The application discloses a method for determining maturity of solid bitumen with extremely high thermal evolution degree.

[0010] Step 1: separating soluble organic matter components in the solid bitumen to be measured to obtain saturated hydrocarbons, and detecting conventional maturity biomarkers in the saturated hydrocarbon components to determine whether the maturity range of the organic matter is invalid or reversed, and determining the maturity range of the organic matter; if invalid, it represents that the solid bitumen is over-mature, and the next step is performed.

[0011] Step 2: detecting whether the saturated hydrocarbon components contain 1,1,3-trimethyl-2-alkylcyclohexane series compounds to determine whether the beta-carotane in the organic matter of the solid bitumen has undergone thermal evolution; if yes, it proves that the beta-carotane in the organic matter of the solid bitumen has undergone thermal evolution, otherwise, it represents that the beta-carotane in the organic matter of the solid bitumen has not undergone thermal evolution.

[0012] Step 3: determining the absolute content of the beta-carotane and the caryophyllane in the solid bitumen organic matter after thermal evolution, and calculating the ratio of the absolute content of the caryophyllane to the beta-carotane.

[0013] Step 4: according to the ratio of the absolute content of the caryophyllane to the beta-carotane, the maturity of the organic matter is calculated by using the following formula: Ro=0.52lnX+3.3469.

[0014] In the preferred embodiment of the application, in step 1, the method for separating the soluble organic matter components in the solid bitumen to be measured to obtain saturated hydrocarbons comprises the following steps.

[0015] Step 11: crushing the solid bitumen sample to be measured and extracting the sample with dichloromethane to obtain an extract.

[0016] Step 12: separating the extract into saturated hydrocarbons, aromatic hydrocarbons, non-hydrocarbons and asphaltene by silica gel column chromatography and alumina column chromatography.

[0017] Further, step 12 specifically uses the following method.

[0018] The extract is added into proper n-hexane, shaken uniformly, precipitated overnight, and the asphaltene is separated out.

[0019] The solution after removing the asphaltene is concentrated and transferred into a solid-phase adsorption column filled with alumina, eluted with an eluent to obtain saturated hydrocarbon, aromatic hydrocarbon and non-hydrocarbon components.

[0020] The solution after removing the asphaltene is concentrated and transferred into a solid-phase adsorption column filled with alumina, eluted with an eluent to obtain saturated hydrocarbon, aromatic hydrocarbon and non-hydrocarbon components.

[0021] Preferably, the eluent is a first eluent composed of n-hexane and dichloromethane and a second eluent composed of dichloromethane and methanol, the volume ratio of n-hexane to dichloromethane in the first eluent is 1:2, and the volume ratio of dichloromethane to methanol in the second eluent is 93:7.

[0022] In the preferred embodiment of the present application, in step 1, the conventional maturity biomarker in the saturated hydrocarbon component is C29 sterane parameters, respectively, C29-ββ / (ββ+αα) and C29-αα20s / (20s+20R) chart and methyphenanthrene discrimination chart.

[0023] In the preferred embodiment of the present application, in step 2, the method for determining whether the β-carotane in the solid bitumen organic matter has undergone thermal evolution is:

[0024] The absolute content of 1,1,3-trimethyl-2-alkylcyclohexane series compounds in the saturated hydrocarbon component is detected by GC-MS;

[0025] The peak time of 1,1,3-trimethyl-2-alkylcyclohexane series compounds is compared with that of n-alkanes with the same carbon number, and when the error of the slope and intercept is within 5%, it is considered that the series compounds are thermal degradation products of cembrene;

[0026] When it is determined that 1,1,3-trimethyl-2-alkylcyclohexane series compounds are thermal degradation products of cembrene, it is determined that the β-carotane has undergone thermal evolution.

[0027] Further, the absolute content of 1,1,3-trimethyl-2-alkylcyclohexane series compounds, the absolute content of β-carotane and cembrene are detected by GC-MS, and the GC-MS detection conditions are:

[0028] Chromatographic column: HP-5MS, 60m x 250μm x 0.25μm;

[0029] Carrier gas: helium;

[0030] Inlet temperature: 300℃;

[0031] Injection method: pulse splitless injection, with an injection flow rate of 1.0mL / min;

[0032] Heating program: the temperature is raised to 100℃ at a rate of 20℃ / min, and then the temperature is raised to 315℃ at a rate of 3℃ / min, and maintained for 20min;

[0033] Mass spectrometer: Agilent-5977B quadrupole mass spectrometer, quadrupole rod temperature is 150 DEG C, ionization energy of EI ion source is 70eV, temperature is 230 DEG C, scanning method is full scan and selective ion scan at the same time.

[0034] Further, the absolute content of the 1,1,3-trimethyl-2-alkylcyclohexane series compound, the absolute content of beta-carotane and the absolute content of saflan are calculated by the following formula respectively:

[0035] 1,1,3-trimethyl-2-alkylcyclohexane series compound absolute content = 1,1,3-trimethyl-2-alkylcyclohexane series compound area / standard sample peak area x standard sample weight / soluble organic matter weight;

[0036] Beta-carotane absolute content = beta-carotane peak area / standard sample peak area x standard sample weight / soluble organic matter weight;

[0037] Saflan absolute content = saflan peak area / standard sample peak area x standard sample weight / soluble organic matter weight.

[0038] The application also discloses applications of saflan and beta-carotane in detecting maturity of solid bitumen with extremely high thermal evolution degree.

[0039] Compared with the prior art, the application has the following beneficial effects:

[0040] The application provides a new method for determining maturity of solid bitumen with extremely high thermal evolution degree, detects by saflan and beta-carotane, enhances geochemical understanding of the evolution process of solid bitumen, and provides valuable insights for evaluation and related exploration work of other highly thermally evolved hydrocarbons. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0042] Figure 1 It is a separation schematic diagram of soluble organic matter components in the solid bitumen to be measured;

[0043] Figure 2 It is a C29 sterane parameter;

[0044] Figure 3 It is MPI and MPR parameters and Ro correlation;

[0045] Figure 4 It is a saflan peak position;

[0046] Figure 5 The peak positions of β-carotene and 1,1,3-trimethyl-2-alkylcyclohexane series compounds are shown.

[0047] Figure 6 A comparison of peak times between 1,1,3-trimethyl-2-alkylcyclohexane series compounds and n-alkanes;

[0048] Figure 7 The graph shows the relationship between stigmacane / β-carotene and Ro. Detailed Implementation

[0049] 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.

[0050] Example 1

[0051] This embodiment focuses on the determination of medium-solid asphalt in the periphery of the Ordos Basin.

[0052] A method for determining the maturity of solid asphalt with extremely high thermal evolution degree includes the following steps:

[0053] Step 1: Separate the soluble organic matter components in the solid asphalt to be tested to obtain saturated hydrocarbons, and detect the conventional maturity biomarkers in the saturated hydrocarbon components to determine whether they are ineffective or reversed, and determine the maturity range of the organic matter; if ineffective, it means that the solid asphalt is over-mature, and proceed to the next step.

[0054] like Figure 1 As shown, the solid asphalt sample to be tested was first pulverized to 100 mesh and extracted with dichloromethane for 72 hours. The extract was separated into saturated hydrocarbons, aromatics, non-hydrocarbons, and asphaltenes by silica gel column chromatography and alumina column chromatography. The separation process was as follows: no more than 30 mg of the extract was added to an appropriate amount of n-hexane and shaken well, and the precipitate was allowed to stand overnight to separate the asphaltenes. After removing the asphaltenes, the solution was concentrated to 0.5 mL and transferred to a solid-phase adsorption column packed with alumina. The saturated hydrocarbons, aromatics, and non-hydrocarbon components were eluted with eluents of n-hexane and dichloromethane (volume ratio 1:2) and dichloromethane and methanol (volume ratio 93:7).

[0055] The saturated hydrocarbon component is analyzed for molecular marker of maturity to ensure that the organic matter has entered the over-mature stage. First, the molecular marker indexes currently applied to the maturity parameter judgment are judged and analyzed. The specific indexes are C29 sterane parameters, specifically C29-ββ / (ββ+αα) and C29-αα20s / (20s+20R) charts and methylphenanthrene discrimination charts (MPI and MPR discrimination charts), as shown in Figure 2 , Figure 3

[0056] As shown in Figure 2 , the points of the C29-ββ / (ββ+αα) and C29-αα20s / (20s+20R) charts fall in the over-mature range, that is, it can be judged that they are all over-mature; as shown in Figure 3 , the MPI and MPR do not have correlation with the maturity Ro measured by the asphalt reflectance (Ro) measured by the Raman spectrum, and the correlation R 2 <0.2, which represents that the molecular marker index C29 sterane parameter of the traditional maturity parameter judgment has failed and cannot be used to judge the maturity of the solid asphalt.

[0057] When the Raman spectrum is used to measure the asphalt reflectance (Ro), the peak height ratio (ID / IG) of the asphalt in the Raman spectrum is the clearest and most convenient to analyze its relationship with Ro. The asphalt reflectance calculation formula is as follows:

[0058] Ro = 5.64*(Id / IG)-0.745

[0059] The experimental test environment temperature is set to 25°C. The light source uses a YAG laser with a wavelength of 532.06 nm, an output power of 350-400 mW, and a line width of less than 0.1 nm. The power of the laser beam irradiated on the sample surface is generally 60-80 mW. The instrument uses a silicon standard sample for wave number calibration, and the calibration peak shift is 520.70 cm-1. The data acquisition time is generally 10-20 seconds, and the number of superimposed acquisition times is 20-70 times.

[0060] Step 2, detecting whether the saturated hydrocarbon component contains 1,1,3-trimethyl-2-alkylcyclohexane series compounds to judge whether the β-carotane in the solid asphalt organic matter has undergone thermal evolution. If yes, it proves that the β-carotane in the solid asphalt organic matter has undergone thermal evolution, otherwise, it represents that the β-carotane in the solid asphalt organic matter has not undergone thermal evolution.

[0061] The 1,1,3-trimethyl-2-alkylcyclohexane series compounds have the following general structural formula:

[0062]

[0063] ​The beta-carotane has a general structure as shown in the following formula:

[0064]

[0065] Since the 1,1,3-trimethyl-2-alkylcyclohexane series compound is only derived from thermal degradation in the petroleum system, it is generally not contained in the low mature oil, and thus, when the 1,1,3-trimethyl-2-alkylcyclohexane series compound is found to exist, it can be considered as a thermal degradation product of carotenane, and the carotenane at this time is obtained by thermal degradation of beta-carotane.

[0066] In this step of the present application, the absolute content of the 1,1,3-trimethyl-2-alkylcyclohexane series compound in the saturated hydrocarbon component is detected by GC-MS.

[0067] The GC-MS analysis is performed by using an Agilent-7890B / 5977B MSD combined gas chromatograph and mass spectrometer. The chromatographic column is HP-5MS (60m x 250μm x 0.25μm), and the carrier gas is helium. The inlet temperature is set to 300℃. The sampling method is pulse split sampling, and the sampling flow rate is maintained at 1.0mL / min. The heating program is: first, the temperature is increased to 100℃ at a speed of 20℃ / min, and then the temperature is increased to 315℃ at a speed of 3℃ / min, and maintained for 20min. The mass spectrometer is an Agilent-5977B quadrupole mass spectrometer, and the quadrupole rod temperature is 150℃. The ionization energy of the EI ion source is 70eV, and the temperature is 230℃. The scanning method is full scan (50-550μm) and selective ion scan at the same time.

[0068] The mass chromatogram of m / z 123 is called, and the retention time and peak shape characteristics are compared by referring to the published literature, so as to identify and detect the 1,1,3-trimethyl-2-alkylcyclohexane series compound and calculate the absolute content, as shown in the following formula: Figure 5 The absolute content calculation method is as follows:

[0069] 1,1,3-trimethyl-2-alkylcyclohexane series compound absolute content = 1,1,3-trimethyl-2-alkylcyclohexane series compound area / standard sample peak area x standard sample weight / weight of soluble organic matter

[0070] On this basis, the 1,1,3-trimethyl-2-alkylcyclohexane series compound is compared with the n-alkane of the same carbon number in the peak time, the slope and intercept are compared, and when the error is within 5%, it is considered that the series compound is a thermal degradation product of carotenane, as shown in the following formula: Figure 6

[0071] ​When the 1,1,3-trimethyl-2-alkylcyclohexane series compounds were determined to be the thermal degradation products of crocetane, it was judged that the β-carotane had undergone thermal evolution.

[0072] Step 3, the absolute content of β-carotane and crocetane in the solid bitumen organic matter after thermal evolution was determined, and the ratio of the absolute content of crocetane to β-carotane was calculated.

[0073] This step also uses gas chromatography-mass spectrometry (GC-MS) technology to analyze and identify the compounds, and the integral areas of different compounds on the mass spectrum are obtained, and the area is used to calculate the content of the compound.

[0074] The GC-MS analysis conditions are the same as those in the above step 2, and are carried out by using an Agilent-7890B / 5977B MSD combined gas chromatograph and mass spectrometer. The chromatographic column is HP-5MS (60m x 250μm x 0.25μm), and the carrier gas is helium. The inlet temperature is set to 300℃. The sampling method is pulse split sampling, and the sampling flow rate is maintained at 1.0mL / min. The heating program is: first increase the temperature to 100℃ at a rate of 20℃ / min, and then increase the temperature to 315℃ at a rate of 3℃ / min, and maintain for 20min. The mass spectrometer is Agilent-5977B quadrupole mass spectrometer, and the quadrupole rod temperature is 150℃. The ionization energy of the EI ion source is 70eV, and the temperature is 230℃. The scanning method is full scan (50-550μm) and selective ion scan at the same time.

[0075] The mass chromatogram of m / z 85 is called, and by referring to the published literature, the retention time and peak shape characteristics are compared, the crocetane compound is identified and detected, and the absolute content is calculated. Crocetane (2,6,11,15-tetramethylhexadecane) is an irregular tail-to-tail C 20 isoprenoid hydrocarbon. The peak position is located between n-C 18 and phytane, as shown in Figure 4 The absolute content calculation method is:

[0076] The absolute content of crocetane = the peak area of crocetane / the peak area of the standard sample x the weight of the standard sample / the weight of the soluble organic matter.

[0077] The mass chromatogram of m / z 125 is called, and by referring to the published literature, the retention time and peak shape characteristics are compared, the β-carotane compound is identified and detected, and the absolute content is calculated. The absolute content calculation method is:

[0078] The absolute content of β-carotane = the peak area of β-carotane / the peak area of the standard sample x the weight of the standard sample / the weight of the soluble organic matter.

[0079] According to the calculation result, the ratio of absolute content of caryophyllane to beta-carotane is calculated.

[0080] Step 4, according to the ratio of absolute content of caryophyllane to beta-carotane, the maturity of organic matter is calculated by the following formula: Ro=0.52lnX+3.3469;

[0081] Wherein, Ro represents the maturity of organic matter, and X is the ratio of absolute content of caryophyllane to beta-carotane.

[0082] Verification example

[0083] Taking the mesosolid bitumen from the same source as that of example 1, i.e. the Erdos basin periphery, as the research target, the thermal maturity thereof is determined by using Raman spectrum to calculate. The relevant Raman parameters are obtained as shown in Table 1, and the maturity range is 2.51-4.61.

[0084] Table 1

[0085]

[0086]

[0087] Figure 7 The caryophyllane / beta-carotane thermal maturity index proposed in example 1 of the present application. It can be obviously seen that the maturity parameter has good correlation with the maturity Ro calculated by using the traditional Raman spectrum, and the correlation R 2 is more than 0.88, which proves the effectiveness of the index.

[0088] The principle and implementation mode of the present application are described by using specific examples in the present application, and the above example is only used to help understand the method and core idea of the present application; meanwhile, for the general technical personnel in the field, the specific implementation mode and application range will be changed according to the idea of the present application. In conclusion, the content of the present specification should not be understood as the limitation of the present application.

Claims

1. A method for determining the maturity of a solid bitumen of very high thermal evolution degree, characterized in that, It comprises the following steps: Step 1, separating soluble organic matter components in the solid bitumen to be tested to obtain saturated hydrocarbons, and detecting conventional maturity biomarkers in the saturated hydrocarbon components to determine whether they are invalid or reversed and determine the maturity range of the organic matter; If invalid, it represents that the solid bitumen is over-mature, and the next step is performed; Step 2, detecting whether the saturated hydrocarbon components contain 1,1,3-trimethyl-2-alkylcyclohexane series compounds to determine whether the beta-carotane in the solid bitumen organic matter has undergone thermal evolution, if yes, it proves that the beta-carotane in the solid bitumen organic matter has undergone thermal evolution, otherwise, it represents that the beta-carotane in the solid bitumen organic matter has not undergone thermal evolution; Step 3, determining the absolute content of beta-carotane and caryophyllane in the solid bitumen organic matter after thermal evolution, and calculating the ratio of the absolute content of caryophyllane to beta-carotane; Step 4, according to the ratio of the absolute content of caryophyllane to beta-carotane, the maturity of the organic matter is calculated by the following formula: Ro = 0.52lnX + 3.3469; Wherein, Ro represents the maturity of the organic matter, and X is the ratio of the absolute content of caryophyllane to beta-carotane.

2. The method of determining the degree of maturity of a very high-heat- evolved solid bitumen according to claim 1, characterized in that, In step 1, the method for separating soluble organic matter components in the solid bitumen to be tested to obtain saturated hydrocarbons comprises the following steps: Step 11, crushing the solid bitumen sample to be tested and extracting with dichloromethane to obtain an extract; Step 12, separating the extract into saturated hydrocarbons, aromatic hydrocarbons, non-hydrocarbons and asphaltene by silica gel column chromatography and alumina column chromatography.

3. The method of determining the degree of maturity of a very high-heat- evolved solid bitumen according to claim 2, wherein, Step 12 specifically adopts the following method: The extract is added to an appropriate amount of n-hexane, shaken uniformly, precipitated overnight, and the asphaltene is separated out; The solution after removing the asphaltene is concentrated and transferred to a solid phase adsorption column filled with alumina, and eluted with an eluent to obtain saturated hydrocarbon, aromatic hydrocarbon and non-hydrocarbon components.

4. The method of determining the degree of maturity of a very high-heat- evolved solid bitumen according to claim 3, wherein, The eluent is a first eluent composed of n-hexane and dichloromethane and a second eluent composed of dichloromethane and methanol, in the first eluent, the volume ratio of n-hexane to dichloromethane is 1:2, in the second eluent, the volume ratio of dichloromethane to methanol is 93:

7.

5. The method of determining the degree of maturity of a very high-heat- evolved solid bitumen according to claim 1, wherein, In step 1, the conventional maturity biomarkers in the saturated hydrocarbon components are C29 sterane parameters, which are C29-ββ / (ββ+αα) and C29-ααα20s / (20s+20R) chart and methylphenanthrene discrimination chart.

6. The method of determining the degree of maturity of a very high-heat- evolved solid bitumen according to claim 1, wherein, In step 2, the method for determining whether the beta-carotane in the solid bitumen organic matter has undergone thermal evolution is as follows: The absolute content of 1,1,3-trimethyl-2-alkylcyclohexane series compounds in the saturated hydrocarbon components is detected by GC-MS; The peak time of 1,1,3-trimethyl-2-alkylcyclohexane series compounds and n-alkane with the same carbon number is compared, the slope and intercept are compared, and when the error is within 5%, it is considered that the series compounds are thermal degradation products of caryophyllane; After it is determined that 1,1,3-trimethyl-2-alkylcyclohexane series compounds are thermal degradation products of caryophyllane, it is determined that beta-carotane has undergone thermal evolution.

7. The method of determining the degree of maturity of a very high-heat- evolved solid bitumen according to claim 6, wherein, The absolute content of 1,1,3-trimethyl-2-alkylcyclohexane series compounds, the absolute content of β-carotane and the absolute content of saflan were detected by GC-MS, and the GC-MS detection conditions were as follows: Chromatographic column: HP-5MS, 60 m x 250 μm x 0.25 μm; Carrier gas: helium; Inlet temperature: 300 ℃; Injection method: pulse splitless injection, and the injection flow rate was kept at 1.0 mL / min; Heating program: the temperature was raised to 100 ℃ at a speed of 20 ℃ / min, and then the temperature was raised to 315 ℃ at a speed of 3 ℃ / min, and was kept for 20 min; Mass spectrometer: Agilent-5977B quadrupole mass spectrometer, the quadrupole rod temperature was 150 ℃, the ionization energy of the EI ion source was 70 eV, the temperature was 230 ℃, and the scanning method was full scan and selective ion scan at the same time.

8. The method of determining the degree of maturity of a very high-heat- evolved solid bitumen according to claim 7, wherein, The absolute content of 1,1,3-trimethyl-2-alkylcyclohexane series compounds, the absolute content of β-carotane and the absolute content of saflan were calculated by the following formulas respectively: Absolute content of 1,1,3-trimethyl-2-alkylcyclohexane series compounds = area of 1,1,3-trimethyl-2-alkylcyclohexane series compounds / area of standard sample peak x weight of standard sample / weight of soluble organic matter; Absolute content of β-carotane = area of β-carotane peak / area of standard sample peak x weight of standard sample / weight of soluble organic matter; Absolute content of saflan = area of saflan peak / area of standard sample peak x weight of standard sample / weight of soluble organic matter.

9. Use of saflan and β-carotane in a method for determining the maturity of a solid bitumen with a very high thermal evolution degree as claimed in claim 1.

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