阅读说明：本技术 一种页岩中已生成烃量的测量方法 (Method for measuring amount of generated hydrocarbons in shale ) 是由 罗霞 侯连华 赵忠英 林森虎 张丽君 庞正炼 付玲 黄凌 孙菲菲 麻伟娇 许昕 于 2020-04-30 设计创作，主要内容包括：本发明公开了一种页岩中已生成烃量的测量方法。该测量方法取密闭取心页岩岩心一分为二,一块立即进行页岩含气量测定,另一块称量后立即经二氯甲烷浸泡抽提、破碎后二氯甲烷再次抽提,再经极性更大的三氯甲烷抽提和抽提后岩石热解实验,可以很好的实现从页岩中已生成的游离态烃类到吸附态烃类、从轻质烃类到重质烃类的全部收集,最大限度保证页岩中已生成烃量的测量精度,克服了现有技术测量不全,数值偏低的缺陷,从而为页岩油原位转化地质评价及有利区优选提供可靠的技术支持。(The invention discloses a method for measuring the amount of hydrocarbons generated in shale. The measurement method divides a closed coring shale core into two parts, one part is used for immediately measuring the shale gas content, the other part is weighed and then is immediately soaked and extracted by dichloromethane, crushed and then extracted again by dichloromethane, and then is subjected to chloroform extraction with higher polarity and rock pyrolysis experiments after extraction, so that the complete collection from the free hydrocarbons generated in the shale to the adsorbed hydrocarbons and from the light hydrocarbons to the heavy hydrocarbons can be well realized, the measurement precision of the generated hydrocarbon content in the shale is ensured to the maximum extent, the defects of incomplete measurement and low numerical value in the prior art are overcome, and reliable technical support is provided for in-situ conversion evaluation of shale oil and preferential selection of a favorable area.)

1. A method for measuring the amount of hydrocarbons formed in shale, the method comprising the steps of:

s100, collecting a to-be-measured closed shale core on site, and weighing two core samples at the same position of the closed shale core respectively;

s200, immediately measuring the gas content of one core sample on site;

s300, immediately immersing another core sample into a dichloromethane solvent after weighing, conveying the core sample to a specified place for ultrasonic vibration extraction for first preset time, and then carrying out total hydrocarbon chromatography quantitative analysis on the extract;

s400, directly crushing the rock sample in the extraction solution, and then continuing ultrasonic vibration extraction for second preset time; then solid-liquid separation, carrying out total hydrocarbon chromatography quantitative analysis on the liquid, and calculating the hydrocarbon content of the part as a first hydrocarbon content; calculating the light hydrocarbon content lost in the sample crushing process as a second hydrocarbon content according to the change of the relative content shown by the chromatographic charts of typical compounds of S300 and S400;

s500, extracting a solid rock sample obtained by solid-liquid separation in S400 in a dichloromethane solvent, carrying out total hydrocarbon chromatography quantitative analysis on the extracted solution, and calculating the hydrocarbon content of the part to be a third hydrocarbon content; weighing quantitative solid powder after drying the rock sample, and performing rock pyrolysis analysis to obtain first rock residual hydrocarbon;

after the rock samples in S600 and S500 are extracted and dried, additionally weighing quantitative solid powder, putting the solid powder into a trichloromethane solvent for extraction, and weighing the solution after extraction and filtration until the solvent is completely volatilized to obtain the fourth hydrocarbon content of the part of the solution; weighing and quantitatively weighing the filtered rock sample after drying, and performing rock pyrolysis analysis to obtain second rock residual hydrocarbon;

s700, determining a correlation among the residual hydrocarbons of the first rock, the residual hydrocarbons of the second rock and the fourth hydrocarbon content according to the pyrolysis of the rocks of S500 and S600, and calculating the content of the hydrocarbons still remaining in the rocks after the chloroform extraction is applied to the rocks to be the fifth hydrocarbon content;

and S800, adding the first hydrocarbon content, the second hydrocarbon content, the third hydrocarbon content, the fourth hydrocarbon content and the fifth hydrocarbon content measured in the previous steps to obtain the total oil content, so as to obtain the total amount of the generated hydrocarbons of the shale.

2. The measuring method according to claim 1, wherein the ultrasonic vibration extraction temperature in S300 and S400 is room temperature to 40 ℃, and the change of the solvent is observed at any time in the process, so that the core sample is submerged by the solvent; the first preset time and the second preset time are both 12-24 h.

3. The method according to claim 1, wherein the crushing in S400 is performed under liquid nitrogen cooling, and the crushing is performed to 60-80 mesh.

4. The measuring method as claimed in claim 1, wherein gas content of the core sample is measured in S200 by SY/T6940-2013 "shale gas content measuring method";

extracting in S500 according to an industry standard SY/T5118-; carrying out rock pyrolysis analysis according to GB/T18602-;

extracting in S600 according to an industry standard SY/T5118-; the analysis of the rock pyrolysis was carried out according to GB/T18602-.

5. The method of claim 1, wherein the total amount of hydrocarbons produced from the shale in S800 comprises gas content and total oil content.

6. The measurement method according to claim 1, wherein S100 specifically comprises:

s110, preparing a gas content on-site measuring instrument, a weighing device and a sealable container containing dichloromethane on a coring site;

s120, when the sealed shale core is taken out of the barrel, processing the sealed shale core; and (3) rapidly sampling after the treatment is finished, respectively taking two core samples at the same position, and weighing after removing the surface sealing liquid and the surface rock of the core samples.

7. The measurement method as recited in claim 6, wherein the core sample weighs 20-40 grams.

8. The measurement method according to claim 6, wherein S300 specifically comprises:

s310, placing the other core sample into a container containing dichloromethane, and sealing the container to ensure that the dichloromethane submerges the core sample by more than 2 cm;

s320, placing the closed container containing the rock sample and the dichloromethane in the S310 into a room temperature cabinet at the room temperature of 40 ℃ below zero, and transporting the closed container back to a laboratory from the site;

s330, placing the closed container into an ultrasonic water bath kettle for ultrasonic vibration, detecting the temperature and the solvent in the experimental process, ensuring that the temperature is between room temperature and 40 ℃, submerging the rock sample with dichloromethane solvent, and carrying out ultrasonic treatment for 12 to 24 hours;

s330: taking out a small amount of extract to perform full hydrocarbon gas chromatography analysis; the remaining sample is ready for use.

9. The measurement method according to claim 8, wherein S400 specifically includes:

s410, putting the residual samples in the S330 into a sample crusher, putting the sample crusher into liquid nitrogen, and crushing the rock samples to 60-80 meshes; the residual sample comprises residual extract and a rock sample soaked in the extract;

s420, simultaneously moving the crushed powder sample and a dichloromethane solvent into a container containing dichloromethane, and sealing;

s430, placing the closed container into an ultrasonic water bath kettle for ultrasonic vibration, detecting the temperature and the solvent in the experimental process, ensuring the temperature to be between room temperature and 40 ℃, submerging the powder sample by using the dichloromethane solvent, and carrying out ultrasonic treatment for 12 to 24 hours;

s440, filtering to perform solid-liquid separation, wherein a powder sample is for later use;

s450, adding a small amount of solution into an internal standard for gas chromatography quantitative analysis, calculating the hydrocarbon content of the part to be a first hydrocarbon content, and putting the rest solution sample into a refrigerator;

s460: and calculating the light hydrocarbon content lost in the sample crushing process as a second hydrocarbon content according to the change of the relative content shown by the chromatographic patterns of the typical compounds of S300 and S400.

10. The measurement method according to claim 9, wherein S700 specifically includes:

s710, carrying out correlation analysis on the first rock residual hydrocarbon, the second rock residual hydrocarbon and the fourth hydrocarbon content, and fitting a relational expression;

s720, according to the relation fitted in the S710, calculating the hydrocarbon content remained in the rock after the chloroform extraction is applied in the S600 as a fifth hydrocarbon content;

preferably, the fitted relation is: (S11-S12) ═ 3.096WO4-0.0506,

the fifth hydrocarbon content is calculated by: WO5 ═ (S12+ 0.0506)/3.096;

wherein WO4 is the fourth hydrocarbon content in% (i.e., expressed as a percentage); WO5 for a fifth hydrocarbon content in%; s11 is first rock residual hydrocarbon in mg/g rock; s12 is second rock residual hydrocarbons in mg/g rock.

Technical Field

The invention relates to the technical field of petroleum exploration, in particular to a method for measuring the amount of generated hydrocarbons in shale.

Background

Shale is an important hydrocarbon source rock layer series and is also an important reservoir layer series, and as exploration becomes mature, exploration of the shale layer series is paid more and more attention by explorators. The United states rate is firstly innovated in a mature-high mature shale layer system through a fracturing technology to obtain oil and gas exploration success, the shale layer system for producing oil and gas mainly adopts marine facies deposition, the shale layer system has the characteristic of interbedded distribution of high-TOC hydrocarbon source rocks and compact reservoirs, the thermal evolution degree of the hydrocarbon source rocks is in an oil and moisture generation stage (Ro is between 1.0 and 1.7 percent), hydrocarbons are subjected to concentration diffusion or short-distance migration, and the resources can be developed and utilized through a horizontal well and a volume transformation technology. The buried depth of the Chinese onshore shale is generally more than 300 meters, but the maturity is generally low (Ro is less than 1.0 percent), and according to the American shale oil exploration and development experience, the shale with Ro less than 1.1 percent has difficulty in obtaining commercial oil flow. However, the shale can be developed in commercial scale through in-situ heating hydrocarbon generation conversion, the potential of oil and gas resources is large, the resource amount of the shale in situ conversion technology with low maturity in China is estimated to be about 700-900 hundred million tons preliminarily, and the shale in situ conversion technology has a great exploration prospect.

Such shale oil resources comprise two parts: firstly, hydrocarbons generated by shale are retained in source rock without migration, and the hydrocarbon content of the part is high, including macromolecular oil gas generated in the early stage of shale and difficult to flow and discharge and micromolecular oil gas generated in the mature stage of shale and easy to flow and discharge; and oil gas generated by kerogen in the shale heating process. Wherein, the measurement of the hydrocarbon amount generated by the shale directly influences the evaluation of the shale in-situ conversion potential and the exploration decision making.

But because the content of the hydrocarbons generated by the shale is very difficult to measure, firstly, the light hydrocarbons generated in the shale are easy to lose; secondly, because the shale pores are very small, the nanopores are dominant, the shale adsorption capacity is strong, and the determination of the heavy hydrocarbon quantity in the nanopores is very difficult. At present, the following techniques exist for determining the content of hydrocarbons generated in shale, but none of them can accurately measure the content of hydrocarbons generated in shale.

The method in the prior art comprises the following steps: the traditional method for measuring the hydrocarbon content comprises the conventional chloroform asphalt 'A' extraction, ROCK-EVAL thermal desorption hydrocarbon and other methods. The pyrolysis method is used for measuring the generated hydrocarbon amount in the shale, namely the crushed shale is heated to 300 ℃ in a pyrolysis furnace and is kept at the constant temperature for 3min, and the content of free hydrocarbon S1 in the shale is quantitatively analyzed by detecting through a hydrogen ion flame detector; then heating to 600 ℃, keeping the temperature for 3min, detecting by a hydrogen ion flame detector, and quantitatively analyzing the hydrocarbon conversion amount of residual hydrocarbon and organic matters in the shale S2. And (3) measuring the generated hydrocarbon amount in the shale by an extraction method, namely extracting the crushed shale by using chloroform, and volatilizing the chloroform to obtain the generated hydrocarbon amount in the shale. The organic solvent suitable for the method can also comprise xylene, solvent gasoline and the like.

The second method in the prior art comprises the following steps: and (4) an indirect analysis method, namely indirectly obtaining the generated hydrocarbon content of the shale by adopting methods such as near infrared spectrum analysis, logging evaluation, indirect calculation of organic carbon content, calculation of shale conductivity equation and the like.

Relevant criteria are: CN104897712A, a method and a system for measuring oil content of shale. Collecting a shale core, and sampling in the middle to perform nuclear magnetic resonance detection; and (3) hermetically crushing, quantifying the mass of light hydrocarbon by using a chromatograph, and calculating the oil content of the shale by using a nuclear magnetic resonance method after oil and water are extracted.

None of the prior art is satisfactory for accurate measurement of the amount of hydrocarbons produced by shale. The pyrolysis method heats the shale to 300 ℃ to obtain the content of residual hydrocarbon S1 in the shale, wherein the residual hydrocarbon S1 comprises light hydrocarbon in the shale and part of heavy hydrocarbon and asphaltene generated in the shale, and part of heavy hydrocarbon and asphaltene are distributed in the rock pyrolysis hydrocarbon S2. Therefore, the measured S1 content fails to evaluate the oil content in shale. The pyrolysis method heats the shale to 600 ℃ to obtain the hydrocarbon conversion amount S2 of residual hydrocarbon and organic matter in the shale, including the heavy hydrocarbon content, the asphaltene content and the oil-gas amount converted by the organic matter in the shale, which cannot represent the generated hydrocarbon amount of the shale, and the S1, the S2 and the combination thereof cannot obtain the generated hydrocarbon amount generated and retained in the shale. Meanwhile, in the heating process of the shale, the crude oil in the shale is partially cracked to generate gas, so that part of oil is lost; no sealing measures are taken in the shale crushing process, so that part of oil content is lost, the used sample amount is small and is about 100mg, and the error is large. Thus, an accurate amount of shale generated hydrocarbons cannot be obtained.

The extraction method does not adopt a sealing measure in the shale crushing process, adopts a non-fresh sample, and is dried after being placed for a period of time, so that part of oil in the shale is lost; when shale is crushed, no sealing and organic solvent protection is adopted, so that part of oil is lost; the organic solvent is chloroform, xylene and solvent gasoline, the boiling points of the organic solvent are respectively 61 ℃, 138.35 ℃ and 80 ℃, the boiling point of light hydrocarbon in the crude oil is about 50 ℃, and partial light hydrocarbon loss is caused in the volatilization process of the organic solvent. The shale nanometer pore is developed, the heavy hydrocarbon in the shale can not be completely extracted by using the chloroform bitumen A extraction method, and the generated hydrocarbon content of the shale is lower.

An indirect analysis method is to adopt indirect methods such as near infrared spectroscopy, well logging, organic carbon content, shale conductivity equation and the like to obtain the amount of hydrocarbons generated by the shale, and a calculation result is calibrated by real generated hydrocarbon measurement data to determine whether the calculation result is reasonable, but the prior art cannot solve the problem of accurate measurement of the oil content of the shale. Thus, indirect analysis also fails to obtain an accurate amount of shale hydrocarbons that have been produced.

Therefore, the prior art scheme can not realize accurate quantitative measurement of the oil content of the shale, and a new method for measuring and calculating the generated hydrocarbon content in the shale is urgently needed to be developed so as to meet the requirements of development and evaluation of in-situ modification of shale oil.

Disclosure of Invention

The invention aims to overcome the defects that the prior art cannot accurately measure the oil content of shale and provides a method for measuring the generated hydrocarbon content in the shale.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for measuring the amount of hydrocarbons formed in shale, as shown in fig. 1, the method comprising the steps of:

s100, collecting a to-be-measured closed shale core on site, and weighing two core samples at the same position of the closed shale core respectively;

s200, immediately measuring the gas content of one core sample on site;

s300, immediately immersing another core sample into a dichloromethane solvent after weighing, conveying the core sample to a specified place for ultrasonic vibration extraction for first preset time, and then carrying out total hydrocarbon chromatography quantitative analysis on the extract;

s400, directly crushing the rock sample in the extraction solution, and then continuing ultrasonic vibration extraction for second preset time; then solid-liquid separation, carrying out total hydrocarbon chromatography quantitative analysis on the liquid, and calculating the hydrocarbon content of the part as a first hydrocarbon content; calculating the light hydrocarbon content lost in the sample crushing process as a second hydrocarbon content according to the change of the relative content shown by the chromatographic charts of typical compounds of S300 and S400;

s500, extracting a solid rock sample obtained by solid-liquid separation in S400 in a dichloromethane solvent, carrying out total hydrocarbon chromatography quantitative analysis on the extracted solution, and calculating the hydrocarbon content of the part to be a third hydrocarbon content; weighing quantitative solid powder after drying the rock sample, and performing rock pyrolysis analysis to obtain first rock residual hydrocarbon;

after the rock samples in S600 and S500 are extracted and dried, additionally weighing quantitative solid powder, putting the solid powder into a trichloromethane solvent for extraction, and weighing the solution after extraction and filtration until the solvent is completely volatilized to obtain the fourth hydrocarbon content of the part of the solution; weighing and quantitatively weighing the filtered rock sample after drying, and performing rock pyrolysis analysis to obtain second rock residual hydrocarbon;

s700, determining a correlation among the residual hydrocarbons of the first rock, the residual hydrocarbons of the second rock and the fourth hydrocarbon content according to the pyrolysis of the rocks of S500 and S600, and calculating the content of the hydrocarbons still remaining in the rocks after the chloroform extraction is applied to the rocks to be the fifth hydrocarbon content;

and S800, adding the first hydrocarbon content, the second hydrocarbon content, the third hydrocarbon content, the fourth hydrocarbon content and the fifth hydrocarbon content measured in the previous steps to obtain the total oil content, so as to obtain the total amount of the generated hydrocarbons of the shale.

The measuring method can obtain the generated hydrocarbon content in the shale to the maximum extent, and provides reliable technical support for shale oil in-situ geological reconstruction and selected area evaluation.

According to the method for measuring the amount of hydrocarbons generated in the shale, the temperature of the ultrasonic vibration extraction in S300 and S400 is between room temperature and 40 ℃, and the change of the solvent is observed at any time in the process, so that the core sample is ensured to be submerged by the solvent; the first preset time and the second preset time are both 12-24 h.

According to the method for measuring the amount of hydrocarbons formed in the shale, the sample is crushed to 60-80 meshes under the cooling of liquid nitrogen in S400.

According to the method for measuring the amount of hydrocarbons generated in the shale, SY/T6940-2013 shale gas content measuring method is adopted to measure the gas content of a core sample in S200;

extracting in S500 according to an industry standard SY/T5118-; carrying out rock pyrolysis analysis according to GB/T18602-;

extracting in S600 according to an industry standard SY/T5118-; the analysis of the rock pyrolysis was carried out according to GB/T18602-.

According to the method for measuring the amount of hydrocarbons produced in the shale, in S800, the total amount of hydrocarbons produced in the shale includes gas content and total oil content.

According to the method for measuring the amount of hydrocarbons generated in shale, S100 specifically includes:

s110, preparing a gas content on-site measuring instrument, a weighing device and a sealable container containing dichloromethane on a coring site;

s120, when the sealed shale core is taken out of the barrel, processing the sealed shale core; rapidly sampling after treatment, respectively taking two core samples at the same position, removing the surface sealing liquid and the surface rock of the core samples, and weighing; preferably, the core sample has a weight of 20-40 grams.

According to the method for measuring the amount of hydrocarbons generated in shale, S300 specifically includes:

s310, placing the other core sample into a container containing dichloromethane, and sealing the container to avoid dichloromethane solvent volatilization as much as possible and ensure that the dichloromethane submerges the core sample by more than 2 cm;

s320, placing the closed container containing the rock sample and the dichloromethane in the S310 into a room temperature cabinet at the room temperature of 40 ℃ below zero, and transporting the closed container back to a laboratory from the site; because the boiling temperature of dichloromethane is 39.5 ℃, in order to avoid the volatilization of dichloromethane solvent as much as possible, the temperature is ensured to be between room temperature and 40 ℃;

s330, placing the closed container into an ultrasonic water bath to carry out ultrasonic vibration (the ultrasonic water bath is placed in a fume hood), detecting the temperature and the solvent in the experimental process, ensuring the temperature to be between room temperature and 40 ℃, submerging the rock sample with dichloromethane solvent, and carrying out ultrasonic treatment for 12 to 24 hours;

s330: a small amount of the extract (about 1mL) was taken out for all-hydrocarbon gas chromatography analysis; the remaining sample is ready for use.

According to the method for measuring the amount of hydrocarbons generated in the shale, S400 specifically includes:

s410, putting the residual samples in the S330 into a sample crusher, putting the sample crusher into liquid nitrogen, and crushing the rock samples to 60-80 meshes (about 0.18 mm); the residual sample comprises residual extract and a rock sample soaked in the extract;

s420, simultaneously moving the crushed powder sample and a dichloromethane solvent into a container containing dichloromethane, and sealing;

s430, placing the closed container into an ultrasonic water bath kettle for ultrasonic vibration, detecting the temperature and the solvent in the experimental process, ensuring the temperature to be between room temperature and 40 ℃, submerging the powder sample by using the dichloromethane solvent, and carrying out ultrasonic treatment for 12 to 24 hours;

s440, filtering to perform solid-liquid separation, wherein a powder sample is for later use;

s450, adding a small amount of solution into an internal standard for gas chromatography quantitative analysis, calculating the hydrocarbon content of the part to be a first hydrocarbon content, and putting the rest solution sample into a refrigerator;

s460: and calculating the light hydrocarbon content lost in the sample crushing process as a second hydrocarbon content according to the change of the relative content shown by the chromatographic patterns of the typical compounds of S300 and S400.

According to the method for measuring the amount of hydrocarbons generated in shale of the present invention, S700 specifically includes:

s710, carrying out correlation analysis on the first rock residual hydrocarbon, the second rock residual hydrocarbon and the fourth hydrocarbon content, and fitting a relational expression;

s720, according to the relation fitted in the S710, calculating the hydrocarbon content remained in the rock after the chloroform extraction is applied in the S600 as a fifth hydrocarbon content;

preferably, the fitted relation is: (S11-S12) ═ 3.096WO4-0.0506,

the fifth hydrocarbon content is calculated by: WO5 ═ (S12+ 0.0506)/3.096;

wherein WO4 is the fourth hydrocarbon content in% (i.e., expressed as a percentage); WO5 for a fifth hydrocarbon content in%; s11 is first rock residual hydrocarbon in mg/g rock; s12 is second rock residual hydrocarbons in mg/g rock.

The difference between the residual hydrocarbons S11 and S12 represents the hydrocarbons extracted by chloroform in S600, and this value has a good linear relationship with the hydrocarbon content WO4 (as fitted in the preferred embodiment of the present invention: the pyrolysis residual hydrocarbon content (S11-S12) ═ 3.096WO4-0.0506), and by this linear relationship formula, it is possible to reverse the hydrocarbon content remaining in the rock without chloroform extraction when the residual hydrocarbons are pyrolyzed to S12 after extraction in S600, and by this formula it is calculated as WO5(WO5 ═ S12+ 0.0506)/3.096).

The invention provides a method for measuring the amount of hydrocarbons generated in shale, which is characterized in that when a sealed core is taken out of a barrel, two samples are taken at the same position, one sample is immediately subjected to shale gas content measurement, and the other sample is immediately put into a sealed container containing a dichloromethane solvent, so that the loss of light components caused by the prior art is effectively prevented. Meanwhile, through ultrasonic vibration of the core sample from block to powder and finally extraction of the powder sample by using a solvent with stronger polarity, the method can well realize the complete collection of the free hydrocarbons to the adsorbed hydrocarbons and the light hydrocarbons to the heavy hydrocarbons generated in the shale, thereby ensuring the measurement precision of the generated hydrocarbon amount in the shale to the maximum extent, overcoming the defects of incomplete measurement and low numerical value in the prior art and further providing reliable technical support for shale oil in-situ conversion geological evaluation and favorable area optimization.

Drawings

FIG. 1 is a flow chart of a method for measuring the amount of hydrocarbons formed in shale provided by the present invention.

Fig. 2 shows the correlation between S11, S12 and WO4 fitted in the example of the present invention.

Detailed Description

In order to more clearly illustrate the invention, the invention is further described below in connection with preferred embodiments. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.

The technical solution of the present invention is explained in detail by a specific embodiment.

The embodiment provides a method for measuring and calculating the amount of hydrocarbons generated in shale, which comprises the following steps:

s10, preparing a gas content on-site measuring instrument, a balance and a sealable container containing a dichloromethane solvent on a coring site, rapidly and respectively taking two samples at the same position when the sealed core is taken out of the barrel, and weighing after removing the sealing liquid and the surface rock, wherein the weight of the samples is 20-40 g.

S20, measuring the gas content of the shale sample to WG according to the SY/T6940-2013 shale gas content measuring method. And putting the other sample into a sealable bottle containing a dichloromethane solvent, sealing to avoid volatilization loss and ensure that the solvent submerges the rock by at least more than 2cm, putting the sealed bottle containing the rock and the dichloromethane solvent into a normal-temperature cabinet, ensuring the temperature to be between room temperature and 40 ℃, avoiding the dichloromethane solvent from volatilizing to the greatest extent, wherein the boiling point temperature of the dichloromethane is 39.5 ℃, and finally transporting the sample back to the laboratory from the site.

S30, firstly, placing the ultrasonic water bath in a fume hood, then placing the closed bottle containing the dichloromethane solvent and the rock core in the ultrasonic water bath for ultrasonic vibration, detecting the temperature and the solvent in the ultrasonic vibration process, ensuring the temperature to be between room temperature and 40 ℃, enabling the dichloromethane solvent to submerge the rock sample, taking out a very small amount of solution (about 1mL) for full hydrocarbon gas chromatography analysis after ultrasonic vibration for 12 to 24 hours, and keeping the rest sample for later use.

S40: placing the S30 sample (comprising rock and dichloromethane) into a sample crusher, placing the sample crusher into liquid nitrogen, and crushing the rock sample to about 0.18mm (60-80 mesh); simultaneously moving the crushed powder sample and a dichloromethane solvent into a closed container containing dichloromethane, and sealing the container; putting the sealed container into an ultrasonic water bath kettle for ultrasonic vibration, detecting the temperature and the solvent in the experimental process, ensuring the temperature to be between room temperature and 40 ℃, submerging the powder sample by using the dichloromethane solvent, and carrying out ultrasonic treatment for 12 to 24 hours; filtering and separating the solution and the rock sample; adding a small amount of internal standard into the solution for gas chromatography quantitative analysis, calculating the hydrocarbon content of the part as the first hydrocarbon content WO1, and putting the rest liquid sample into a refrigerator; calculating the light hydrocarbon content lost in the sample crushing process as a second hydrocarbon content WO2 according to the change of the relative content shown by the chromatographic patterns of typical compounds S30 and S40; powder samples were ready for use.

S50, putting the rock sample to be used of S40 into a dichloromethane solvent, extracting according to an industry standard SY/T5118-; weighing quantitative solid powder after the rock sample is dried, and carrying out rock pyrolysis analysis according to GB/T18602-.

S60: and (3) weighing the sample in S50, then placing the sample into a trichloromethane solvent, extracting according to an industry standard SY/T5118-.

Step S70: the hydrocarbon content still remaining in the rock after the extraction with chloroform was calculated as a fifth hydrocarbon content WO5, based on the correlations between the pyrolysis measurements of S11, S12 and WO4 for the rocks S50 and S60.

Step S80: the measured values of the above steps are added to obtain the total oil content WO of WO1, WO2, WO3, WO4 and WO5, so as to obtain the total amount of hydrocarbons (including gas content WG and total oil content WO) generated by the shale.

With the above measurement method of the present embodiment, the amount of hydrocarbons that have been produced from the shale of the erudos basin length 73 was measured.

And respectively collecting two shale samples at the same depth within 30 minutes after the 85-well sealed core is taken out of the barrel, and collecting 38 shale samples in total, wherein the sample depths are shown in table 1.

And removing the sealing liquid on the surface layer of the core by cotton yarns within 5 minutes, and removing the surface layer of the core by 2 cm. 19 samples are collected and the gas content of the shale (table 1) is measured immediately according to SY/T6940-2013 standard, in addition, 19 samples are respectively put into a closed bottle containing dichloromethane, the solvent is ensured to submerge the rock for at least more than 2cm, then the closed bottle containing the rock and the dichloromethane solvent is put into a normal temperature cabinet, the temperature is ensured to be 40 ℃ below zero, the dichloromethane solvent is prevented from volatilizing as far as possible, the boiling temperature of the dichloromethane is 39.5 ℃, and finally, the samples are transported back to the laboratory from the site.

Putting an ultrasonic water bath into a fume hood, then putting a closed bottle containing a dichloromethane solvent and a rock core into the ultrasonic water bath for ultrasonic vibration, detecting the temperature and the solvent in the ultrasonic vibration process, ensuring the temperature to be between room temperature and 40 ℃, ensuring the dichloromethane solvent to submerge a rock sample, taking out a very small amount of solution (about 1mL) for full hydrocarbon gas chromatography after ultrasonic vibration is carried out for 12 to 24 hours, putting the rest samples (comprising the rock and the dichloromethane) into a sample crusher, putting the sample crusher into liquid nitrogen, and crushing the rock sample to about 0.18mm (60 to 80 meshes); simultaneously moving the crushed powder sample and a dichloromethane solvent into a closed bottle containing dichloromethane, sealing the bottle, then placing the bottle into an ultrasonic water bath kettle for ultrasonic vibration, detecting the temperature and the solvent in the experimental process, ensuring the temperature to be between room temperature and 40 ℃, submerging the powder sample by the dichloromethane solvent, and carrying out ultrasonic treatment for 12 to 24 hours; filtering and separating the solution and the rock sample; a small amount of internal standard was added to the solution for quantitative analysis by gas chromatography, and the hydrocarbon content of this fraction was calculated to be WO1 (Table 1).

The light hydrocarbon content lost during the sample comminution process WO2 (table 1) was calculated from the change in relative content of the integrated areas of the chromatographic profiles of the two compounds selected nC7 and nC8, based on two chromatographic analyses.

After ultrasonic treatment, the powder sample is put into a dichloromethane solvent, extraction is carried out according to the industrial standard SY/T5118-2005, and the total hydrocarbon chromatography quantitative analysis is carried out on the solution after extraction, and the hydrocarbon content of the part is calculated to be WO3 (Table 1).

Weighing quantitative solid powder GB/T18602-; weighing the rest solid powder sample, putting the weighed sample into a trichloromethane solvent, extracting according to an industry standard SY/T5118-.

The hydrocarbon content WO5 (table 1) still remaining in the rock after the extraction with chloroform was calculated from the correlation between S11, S12 and WO4 determined by the pyrolysis of the rock.

The fitted relationship of S11, S12 and WO4 is shown in fig. 2, with y being 3.096x-0.0506, with x on the abscissa being WO4 in% (i.e. expressed as a percentage) and y on the ordinate being (S11-S12) in mg/g rock; WO5 was then calculated according to WO5 ═ (S12+0.0506)/3.096) and the results are given in table 1.

The total oil content WO (Table 1) is obtained by adding WO1, WO2, WO3, WO4 and WO5, so as to obtain the total amount of hydrocarbons generated by the shale (comprising the gas content WG and the total oil content WO).

TABLE 1 oil content and Total oil and gas contents of shale in each step of this example

Table 2 table of analysis data of rock pyrolysis in different stages in this embodiment

The method can accurately obtain the content of all generated oil and gas in the shale, particularly the content of generated gas and light components in the shale, thereby effectively preventing the loss of the light components caused by the prior art and overcoming the defects that the hydrocarbon content generated in the shale can not be accurately measured in the prior art.

It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that other variations or modifications may be made on the basis of the above description, and all embodiments may not be exhaustive, and all obvious variations or modifications may be included within the scope of the present invention.