阅读说明：本技术 用于定量岩石样品中黄铁矿硫和有机硫的方法 (Method for quantifying pyrite sulfur and organic sulfur in rock samples ) 是由 A·阿布索 V·拉穆赫-瓦赫 D·皮尔洛特 I·科瓦列斯基 B·加西亚 T·瓦格纳 C· 于 2019-06-28 设计创作，主要内容包括：岩石样品在惰性气氛中经受加热过程,由该加热产生的流出物被氧化,对所释放的基于烃的化合物、CO、CO<Sub>2</Sub>和SO<Sub>2</Sub>进行测量,并由此推断出热解黄铁矿硫含量。然后由在惰性气氛中加热所获得的残余物在氧化气氛中加热,并对所释放的CO和CO<Sub>2</Sub>进行测量。至少根据热解黄铁矿硫含量和参数来确定热解硫含量,所述参数是样品有机物质的氧含量和氢含量的函数。还可以根据黄铁矿硫含量和在氧化气氛中的加热过程期间的SO<Sub>2</Sub>测量来确定有机硫含量。(The rock sample is subjected to a heating process in an inert atmosphere, the effluent resulting from this heating is oxidized, the liberated hydrocarbon-based compound, CO 2 And SO 2 Measurements were made and the pyrolysed pyrite sulfur content was inferred therefrom. The residue obtained from heating in an inert atmosphere is then heated in an oxidizing atmosphere and the released CO and CO are reacted 2 The measurement is performed. The pyrolysis sulfur content is determined based on at least the pyrolysis pyrite sulfur content and a parameter that is a function of the oxygen content and the hydrogen content of the organic matter of the sample. Can also be based on yellowIron ore sulfur content and SO during heating process in oxidizing atmosphere 2 Measuring to determine the organic sulphur content.)

1. A method for quantifying pyritic sulphur in a sedimentary rock sample, wherein at least the following steps are employed:

heating the sample in an inert atmosphere between a first temperature of 80 ℃ to 320 ℃ and a second temperature of 600 ℃ to 700 ℃ while following a first temperature course, and continuously measuring the amount of CO and the CO released during the first temperature course₂Amount of hydrocarbon-based compound;

B. continuously oxidizing at least a portion of the effluent resulting from said heating of said sample in an inert atmosphere, continuously measuring SO released by said oxidation of said effluent₂The amount being a function of the time of said heating in an inert atmosphere and being determined by said SO₂Quantifying at least one of the sulfur contents of the pyrolized pyrites

C. Heating the residue of the sample obtained from the heating in an inert atmosphere between a third temperature of 280 ℃ to 320 ℃ and a fourth temperature higher than or equal to 800 ℃ in an oxidizing atmosphere while following a second temperature course, and continuously measuring during the second temperature courseThe amount of CO released and CO₂The amount of (c);

characterized in that at least one pyrite sulfur content S contained in said sample^PyriteIs determined based on the following type of formula:

wherein α is a parameter representing the ratio of the pyrolysed pyrite sulfur relative to the total sulfur, β is a parameter representing the effect of a mineral matrix on the ratio, γ is a parameter representing the effect of an organic matrix on the ratio, the values of the parameters α and β are predetermined, and the parameter γ is determined by an equation of the type:

γ＝f(OI，HI)

wherein f is a function of at least one oxygen index OI and a hydrogen index HI that is at least the amount of the hydrocarbon-based compound measured during the heating in the inert atmosphere and the amount of the CO and the CO measured during the first and second temperature processes₂And the oxygen index OI is at least the amount of CO and the CO measured during the first and second temperature processes₂As a function of the amount of (c).

2. The method of claim 1, wherein the function f is a linear combination of the oxygen index OI and the hydrogen index HI, represented by the following type of formula: γ ═ a + OI + b × HI + c, where a, b, and c are predetermined constants.

3. The method of claim 2, wherein the constant a is 0.28 to 0.46, and preferably equal to 0.37.

4. A method according to any one of claims 2 and 3, wherein the constant b is from-0.007 to-0.005, and preferably equal to-0.006.

5. The method according to any one of claims 2 to 4, wherein the constant c is between 4.99 and 6.49 and preferably equal to 5.74.

6. Method according to any one of the preceding claims, wherein the hydrogen index HI is determined according to the following type of formula:

wherein the content of the first and second substances,

-S2 is the amount of hydrocarbon-based compound cracked during the first temperature course, S2 is determined from the amount of hydrocarbon-based compound released during the heating in an inert atmosphere,

-TOC is the total organic carbon content of the sample, written in the form TOC (% by weight) ═ PC + RC, where PC is the carbon emitted by the counter-carbon pairs CO and CO released during the first temperature course₂An organic carbon content from pyrolysis of the sample determined by performing the measurement, and wherein RC is a measure of the amount of CO and CO released during the second temperature course₂The residual organic carbon content of the sample determined by performing the measurement.

7. The method according to any one of the preceding claims, wherein the oxygen index OI is determined according to the following type of formula:

wherein:

-S3CO₂is CO measured between the first temperature of the first temperature course and a first intermediate temperature of the first temperature course₂In an amount of from 350 ℃ to 450 ℃, preferably equal to 400 ℃;

-TOC is the total organic carbon content of the sample, written TOC (% by weight) ═ PC + RC, where PC is the carbon emitted by the counter-carbon pairs CO and CO released during the first temperature course₂From the sample determined by performing the measurementThe organic carbon content of the pyrolysis of the product, and wherein RC is due to CO and CO released during the second temperature course₂The residual organic carbon content of the sample determined by performing the measurement.

8. The method of any one of claims 6 and 7, wherein the pyrolytic organic carbon content, PC, of the sample is determined according to a formula of the type:

and is

-S3CO₂Is CO measured between the first temperature of the first temperature course and a first intermediate temperature of the first temperature course₂In an amount of from 350 ℃ to 450 ℃, preferably equal to 400 ℃,

-S3CO is the amount of CO measured between the first temperature of the first temperature course and a second intermediate temperature of the first temperature course, the second intermediate temperature being between 500 ℃ and 600 ℃, preferably equal to 550 ℃;

-S3' CO is the amount of CO measured between the second intermediate temperature of the first temperature process and the second temperature of the first temperature process.

9. The method according to any one of claims 6 to 8, wherein the residual organic carbon content RC of the sample is determined according to an equation of the type:

wherein, S4CO and S4CO₂Corresponding to CO and CO respectively measured between the third temperature of the second temperature course and an intermediate temperature of the second temperature course₂In an amount such that the intermediate temperature is between 600 ℃ and 700 ℃, preferably equal to 650 ℃.

10. The method of any one of the preceding claims, wherein the sample is of a reservoir rock type, and wherein the first temperature range is 100 ℃ to 200 ℃.

11. The method of any one of the preceding claims, wherein the sample is a conventional source rock or an immature shale block type, and wherein the first temperature range is 280 ℃ to 320 ℃.

12. The method of any one of the preceding claims, wherein the sample is of the oil-or gas-bearing shale block type, and wherein the first temperature range is from 80 ℃ to 120 ℃.

13. The method according to any one of the preceding claims, wherein the parameter a is between 0.40 and 0.46, and preferably equal to 0.43.

14. The method of any one of the preceding claims, wherein the rock sample is clay-type and the parameter β is 0.04 to 0.7, and preferably equal to 0.38.

15. The method according to any one of claims 1 to 13, wherein the rock sample is of the marl type and the parameter β is between 0.7 and 0.9, and preferably equal to 0.78.

16. The method of any one of claims 1 to 13, wherein the rock sample is of the limestone type and parameter β is 0.85 to 0.97, and preferably equal to 0.9.

17. The method of any one of the preceding claims, wherein SO released during the course of the second temperature is additionally measured₂From the SO measured during the first temperature course₂To determine at least one pyrolysis sulfur content S_PyrolysisAnd from the SO measured during the second temperature course₂To determine the sulfur oxide content S_{Oxidation by oxygen}And, at least from the pyrite sulfur content S^PyriteThe pyrolysis sulfur content S_PyrolysisAnd said sulfur oxide content S_{Oxidation by oxygen}To determine the organic sulfur content S^{Organic compounds}。

18. The method of claim 17, wherein the fourth temperature range is 800 ℃ to 900 ℃, wherein the organic sulfur content S is^{Organic compounds}Determined according to the following formula: s^{Organic compounds}＝S_Pyrolysis+S_{Oxidation by oxygen}-S^Pyrite。

19. A method according to claim 17, wherein the fourth temperature is above 1150 ℃ and preferably below 1250 ℃, wherein the sulphate sulphur content

Technical Field

The present invention relates to the technical field of the petroleum industry and more specifically to the field of exploration and development of geological formations in which hydrocarbons are trapped.

More particularly, the invention relates to the characterization and quantification of sulfur present in sedimentary rock, such as marine clays rich in organic materials.

Background

To meet the ever-increasing energy demand, the petroleum industry is increasingly devoted to the production of unconventional crude oils, which have higher sulfur contents than conventional oils. However, the sulfur content of unconventional crude oils, as well as the type of sulfur-containing organic compounds they contain, are key parameters for the quality of such oils and refined products derived therefrom. Furthermore, regulations dictate that products derived from refining have increasingly lower sulfur contents. It is therefore important to know how to accurately characterize and quantify the sulfur present in these sulfur crude oil derived rocks.

In the case of oil bearing rock, the two major sulfur compounds are organic sulfur and pyritic sulfur. The quantification of organic sulfur is independent of pyritic sulfur and is important in oil exploration because it allows one to accurately know the amount of sulfur associated with organic matter in source rocks from which the sulfur is present in the oil produced. In particular, the separate quantification of pyritic sulphur and organic sulphur makes it possible to:

characterization of the organic matter type of the source rock and prediction of the quality of the oil produced by the source rock with respect to its sulphur content: indeed, the characterization of the type of organic matter of a source rock is generally based on the organic matter in questionCarbon (C), hydrogen (H) and oxygen (O). Conventional characterization of this organic species type is carried out by means of a conventional Van crick torvum diagram (Van Krevelen diagram) showing the hydrogen/carbon (H/C) atomic ratio as a function of the oxygen/carbon (O/C) atomic ratio. Since the petroleum-producing potential of organic matter is determined by its H, C and O composition, this figure allows the differentiation of three organic matter types according to their petroleum potential. In fact, the map may relate to the source of the organic matter and the deposition environment. Generally, organic substances of lake type (type I), ocean type (type II) and land type (type III) are distinguished. The quantification of sulphur in organic matter is independent of the sulphur in pyrite (or pyrite sulphur), which provides an additional parameter enabling a more refined characterization of the type of organic matter and therefore its deposition environment and the type of petroleum it can produce. This finer characterization is done with an expanded three-dimensional van krey wiln diagram: H/C being O/C and S^{Organic compounds}Function of/C, wherein S^{Organic compounds}Is the content of organic sulfur. This expanded plot allows for more refined differentiation of various organic species types, particularly identifying type IS and type IIS organic species that have the same source as type I and type II but contain sulfur and may deposit in anoxic or calm sea environments. The presence of this sulfur also indicates that the petroleum oil obtained from the cracking of the organic material will have a higher sulfur content. In general, information about the type of organic matter of the source rock provides information about the potential of the source rock to produce oil and information about the expected quality of the oil, particularly about its sulfur content;

-providing parameters other than green rock contrast: indeed, petroliferous rock comparisons are a very important study that must be performed by those skilled in the art to evaluate petroleum systems. It consists in establishing a link between the oils contained in the reservoir (reservoir) and the source rocks from which they originate. It is known that cracking of source rocks containing organic materials rich in sulfur results in the formation of petroleum and gas also rich in sulfur, and therefore a method for quantifying the presence of sulfur in organic materials (independent of sulfur in pyrite) provides a key parameter for petrochemicals comparisons.

Disclosure of Invention

Method according to the invention

The invention relates to a method for quantifying pyritic sulphur in sedimentary rock samples, wherein at least the following steps are adopted:

A. while following the course of the first temperature, in an inert atmosphere, at a first temperature of 80 ℃ to 320 ℃ and a second temperature of 600 ℃ to 700 ℃Between temperatures, heating the sample, and continuously measuring the amount of CO and CO released during the first temperature course₂Amount of hydrocarbon-based compound;

B. continuously oxidizing at least a portion of the effluent resulting from said heating of said sample in an inert atmosphere, continuously measuring SO released by said oxidation of said effluent₂The amount being a function of the time of said heating in an inert atmosphere and being dependent on said SO₂Quantifying at least one of the sulfur contents of the pyrolized pyrites

C. Heating the residue of the sample obtained from the heating in an inert atmosphere between a third temperature of 280 ℃ to 320 ℃ and a fourth temperature higher than or equal to 800 ℃ in an oxidizing atmosphere while following a second temperature course, and continuously measuring the amount of CO and the CO released during the second temperature course₂The amount of (c);

characterized in that at least one pyrite sulfur content S contained in said sample^PyriteIs determined based on the following type of formula:

wherein α is a parameter representing the ratio of the pyrolysed pyrite sulfur relative to the total sulfur, β is a parameter representing the effect of a mineral matrix on the ratio, γ is a parameter representing the effect of an organic matrix on the ratio, the values of the parameters α and β are predetermined, and the parameter γ is determined by an equation of the type:

γ＝f(OI，HI)

wherein f is a function of at least one oxygen index OI and a hydrogen index HI, which is the amount of at least the hydrocarbon-based compound measured during the heating in the inert atmosphere and the amount of the CO and the CO measured during the first and second temperature processes₂And the oxygen indexOI is at least the amount of said CO and said CO measured during said first and second temperature processes₂As a function of the amount of (c).

According to an embodiment of the invention, the function f may be a linear combination of the oxygen index OI and the hydrogen index HI, which may be represented by the following type of formula: γ ═ a ═ OI + b ­ HI + c, where a, b, and c are predetermined constants.

Advantageously, the constant a may be between 0.28 and 0.46, and may preferably be equal to 0.37.

Preferably, the constant b may be-0.007 to-0.005, and may preferably be equal to-0.006.

Preferably, the constant c may be 4.99 to 6.49, and may preferably be equal to 5.74.

According to one embodiment of the invention, the hydrogen index HI may be determined according to the following type of formula:

wherein the content of the first and second substances,

-S2 is the amount of hydrocarbon-based compound cracked during the first temperature course, S2 is determined from the amount of hydrocarbon-based compound released during the heating in an inert atmosphere,

-TOC is the total organic carbon content of the sample, written in the form TOC (% by weight) ═ PC + RC, where PC is the carbon emitted by the counter-carbon pairs CO and CO released during the first temperature course₂The pyrolysed organic carbon content of the sample determined by the measurement being made and wherein RC is a measure of the amount of CO and CO released during the second temperature course₂The residual organic carbon content of the sample determined by performing the measurement.

According to one embodiment of the invention, the oxygen index OI may be determined according to the following type of equation:

wherein:

-S3CO₂is CO measured between the first temperature of the first temperature course and a first intermediate temperature of the first temperature course₂In an amount of from 350 ℃ to 450 ℃, preferably equal to 400 ℃,

-TOC is the total organic carbon content of the sample, written TOC (% by weight) ═ PC + RC, where PC is the carbon emitted by the counter-carbon pairs CO and CO released during the first temperature course₂An organic carbon content from pyrolysis of the sample determined by performing the measurement, and wherein RC is a measure of the amount of CO and CO released during the second temperature course₂The residual organic carbon content of the sample determined by performing the measurement.

According to one embodiment of the invention, the pyrolytic organic carbon content PC of the sample is determined according to the following type of formula:

and is and

-S3CO₂is CO measured between the first temperature of the first temperature course and a first intermediate temperature of the first temperature course₂In an amount of from 350 ℃ to 450 ℃, preferably equal to 400 ℃;

-S3CO is the amount of CO measured between the first temperature of the first temperature course and a second intermediate temperature of the first temperature course, the second intermediate temperature being between 500 ℃ and 600 ℃, preferably equal to 550 ℃;

-S3' CO is the amount of CO measured between the second intermediate temperature of the first temperature process and the second temperature of the first temperature process.

According to one embodiment of the invention, the residual organic carbon content RC of the sample is determined according to an equation of the type:

wherein, S4CO and S4CO₂Corresponding to CO and CO respectively measured between the third temperature of the second temperature course and an intermediate temperature of the second temperature course₂In an amount such that the intermediate temperature is between 600 ℃ and 700 ℃, preferably equal to 650 ℃.

According to a first alternative of the invention, the sample is of a reservoir rock type and the first temperature may be from 100 ℃ to 200 ℃.

According to a second alternative of the invention, wherein the sample is of conventional source rock or immature shale block (shale play) type, the first temperature may be 280 ℃ to 320 ℃.

According to a third alternative of the invention, wherein the sample is of the oil-or gas-bearing shale block type and the first temperature may be 80 ℃ to 120 ℃.

According to an embodiment of the invention, said parameter α may be between 0.40 and 0.46, and is preferably equal to 0.43.

According to an embodiment of the invention, wherein the rock sample may be clay-type, the parameter β may be 0.04 to 0.7, and preferably equal to 0.38.

According to an embodiment of the invention, wherein the rock sample may be of the marl type, and for this purpose the parameter β may be 0.7 to 0.9, and preferably equal to 0.78.

According to an embodiment of the invention, wherein the rock sample may be of the limestone type and for this the parameter β may be 0.85 to 0.97, and preferably equal to 0.9.

According to a variant of an embodiment of the invention, the SO released during the course of the second temperature can also be measured₂Can be determined from the SO measured during the first temperature course₂To determine at least one pyrolysis sulfur content S_PyrolysisAnd from the SO measured during the second temperature course₂To determine the sulfur oxide content S_{Oxidation by oxygen}And, may be determined from at least the pyrite sulfur content S^PyriteThe pyrolysis sulfur content S_PyrolysisAnd said sulfur oxide content S_{Oxidation by oxygen}To determine the organic sulfur content S^{Organic compounds}。

According to an embodiment of the present invention, wherein the fourth temperature is 800 ℃ to 900 ℃, the organic sulfur content S may be determined according to the following formula^{Organic compounds}：S^{Organic compounds}＝S_Pyrolysis+S_{Oxidation by oxygen}-S^Pyrite。

According to another alternative embodiment of the invention, wherein said fourth temperature is higher than 1150 ℃ and preferably lower than 1250 ℃, said SO measurable during said second temperature course₂Amount to determine sulfate sulfur content

And the organic sulfur content can be deduced from the following formula:

further features and advantages of the method according to the invention will become apparent after reading the following description of non-limiting exemplary embodiments, with reference to the attached drawings described hereinafter.

Drawings

FIG. 1a shows the use of SO during the heating process under an inert atmosphere to which the rock sample is subjected₂One example of a detector taking a measurement.

FIG. 1b shows the use of SO during the heating process under an oxidizing atmosphere to which the rock sample is subjected₂One example of a detector taking a measurement.

FIG. 2 shows SO released during the heating process under an inert atmosphere for four different weight samples of pure igneous pyrite₂Representative curve of the amount.

Figure 3a shows a representative histogram of mineral matrix effects as a function of the mineral mix class studied.

Figure 3b shows a representative bar graph of the average effect of clay, carbonate and intermediate formation on the sulphur ratio in the pyrite released during pyrolysis as a function of the mineral mixture category studied.

Figure 3c shows the evolution of mineral matrix effects as a function of mineral carbon.

Figure 4 shows the comparison between the effect of organic matter obtained by analyzing the mixture composed of pyrite and various types of organic matter and the effect of organic matter determined by the method of the invention.

FIG. 5a shows the total sulfur content of various types of samples determined by the method of the invention as a function of the actual total sulfur content of these samples.

FIG. 5b shows the pyritic sulphur content of the various types of samples determined by the method of the invention as a function of the actual pyritic sulphur content of these samples.

Figure 5c shows the organic sulphur content of various types of samples determined by the method of the invention as a function of the actual organic sulphur content of these samples.

FIG. 5d shows the pyritic sulphur content of various types of samples determined by the prior art method as a function of the actual pyritic sulphur content of these samples.

Figure 5e shows the organic sulphur content of various types of samples determined by prior art methods as a function of the actual organic sulphur content of these samples.

Detailed Description

Detailed description of the method

In general, one of the objects of the present invention is a method for the accurate quantification of pyritic sulphur present in sedimentary rock samples. In particular, the present invention can separately quantify pyritic sulfur and organic sulfur. Advantageously, according to the method of the present invention, in addition to pyritic sulphur, the organic sulphur present in the sedimentary rock sample can be quantified.

The invention can be applied to any type of sedimentary rock containing pyrite and/or organic matter containing sulphur. In particular, the invention is applicable to source, reservoir or shale zone (shale) samples.

In general, rock samples may be obtained, for example, from core cuttings in the associated subterranean formation or may be produced from rock cuttings from drilling. Advantageously, the samples obtained are prepared (by washing, screening, sorting, etc.) to remove impurities (e.g., drilling mud, contaminants, etc.), and then ground by hand or with a mechanical grinder.

The process according to the invention can be advantageously used, but not in a limiting manner, as described in detail in patent EP2,342,557(US8,796,035)

Device [ France IFP New energy company (IFP Energies Nouvelles, France)]And (5) implementing.

The method according to the invention comprises at least the following steps:

1. heating process under inert atmosphere (pyrolysis)

2. Heating process under oxidizing atmosphere (oxidation)

3. And (4) quantifying the pyrite sulfur.

According to a first variant, the method according to the invention may further comprise: and a fourth step of quantifying organic sulfur after the step 3 is finished.

According to a second variant, the method may further comprise the steps of: one or more parameters required to perform the following step 3 are calibrated. This calibration step can likewise be carried out before step 1 or before step 2 or before step 3, or in parallel with one of these steps 1 or 2.

Steps 1 to 3 of the method according to the invention, as well as the first and second variants of the method according to the invention, are described below.

1. Heating process under inert atmosphere (pyrolysis)

During this step, the relevant sedimentary rock sample is heated in an inert atmosphere (for example, in a nitrogen or helium gas flow) according to a predetermined time-varying temperature program (sub-step 1.1 below). At the same time, at least part of the effluent resulting from this heating is subjected to a continuous oxidation in an inert atmosphere (substep 1.2, below).

1.1. Heating in inert atmosphere

According to the invention, the sample is heated according to a predetermined temperature course by pyrolysis between a temperature T1 and a temperature T2, the temperature T1 being between 80 ℃ and 320 ℃, the temperature T2 being between 600 ℃ and 700 ℃, preferably 650 ℃.

According to one embodiment of the invention, the course of the temperature of heating in the inert atmosphere may consist of a temperature gradient (or heating rate) ranging from 0.1 ℃/min to 30 ℃/min, preferably from 20 ℃/min to 30 ℃/min, more preferably equal to 25 ℃/min. According to another embodiment of the invention, the course of the temperature of the heating in the inert atmosphere may comprise at least one stationary temperature phase during which the temperature is kept constant and at least one temperature gradient (or heating rate), which may be arranged before or after the at least one stationary phase.

According to an embodiment of the invention in which the sample analyzed is a reservoir rock, the temperature T1 ranges from 100 ° to 200 ℃ and is preferably equal to 180 ℃. As regards the relevance of this temperature range to this type of rock sample, reference may be made to patent EP 0691540B 1.

According to one embodiment of the invention, wherein the sample analyzed is a conventional source rock or an immature shale block (for example black shale), the temperature T1 is between 280 ° and 320 ℃ and preferably equal to 300 ℃. Regarding the correlation of this temperature range with this type of rock sample, reference may be made to Behar et al, 2001.

According to one embodiment of the invention, wherein the sample analyzed is an oil-containing shale zone (e.g. oil shale) or a gas-containing shale zone (e.g. gas shale), the temperature T1 is between 80 ° and 120 ℃ and preferably equal to 100 ℃. As regards the relevance of this temperature range to this type of rock sample, reference may be made to patent FR 3021748 (application US 2015/0346179).

According to the invention, the amount of carbon monoxide CO and the carbon dioxide CO released during the heating process in an inert atmosphere are measured₂Amount of hydrocarbon-based compound. Hydrocarbon-based compounds can be measured by flame ionization detector or FID, and can be split by infrared IRPhotometer for CO and CO₂The measurement of (2).

According to a preferred embodiment of the invention, based on carbon monoxide and carbon dioxide measurements made during the heating process in an inert atmosphere, it can be determined that:

amount of carbon monoxide of organic origin only S3 CO: this amount corresponds to the amount of carbon monoxide measured between the temperature T1 of the heating process in an inert atmosphere and a first intermediate temperature T1 'of the heating process in this inert atmosphere, T1' being between 500 ℃ and 600 ℃, preferably equal to 550 ℃;

amount of carbon monoxide of organic and mineral origin S3' CO: this amount corresponds to the amount of carbon monoxide measured between a first intermediate temperature T1' of the heating process in an inert atmosphere and a second temperature T2 of the heating process in an inert atmosphere;

amount of carbon dioxide of organic origin only S3CO₂Measured between the temperature T1 of the process in an inert atmosphere and a second intermediate temperature of the heating process in an inert atmosphere, ranging from 350 ℃ to 450 ℃, preferably equal to 400 ℃.

According to one embodiment of the invention, the pyrolytic organic carbon content PC is determined according to the following type of formula:

wherein Q is the amount of hydrocarbon-based compound measured during the heating process in an inert atmosphere.

1.2. Oxidation of the effluent obtained by heating in an inert atmosphere

According to the invention, at least a portion of the effluent released during pyrolysis is oxidized upon release. Thus, the sulfur-containing gases present in the pyrolysis effluent are oxidized to SO upon release₂. According to one embodiment of the invention, the oxidation of the pyrolysis effluent is carried out by a combustion chamber (e.g., an oxidation oven) in the presence of an oxygen-containing gas and optionally a catalyst.

According to the invention, the pyrolysis is carried out by SO₂Detectors such as Ultraviolet (UV) or Infrared (IR) spectrophotometersMeasuring the SO produced thereby₂. SO released during pyrolysis is thus obtained₂As a function of pyrolysis time and/or temperature.

FIG. 1a shows an example of a curve (denoted by C1), which is SO₂Measurement of quantities (more precisely, from SO)₂The amplitude a measured by a detector, such as an ultraviolet spectrophotometer) as a function of the pyrolysis time (denoted by T) and also shows the evolution of the pyrolysis temperature (denoted by T) as a function of the pyrolysis time in dashed lines. For this example, and for purposes of illustration, temperature T1 is selected to be equal to 300 ℃, temperature T2 is selected to be equal to 650 ℃, temperature T3 is selected to be equal to 300 ℃, and temperature T4 is selected to be equal to 1200 ℃. It can be observed that the curve C1 includes a plurality of peaks. In particular, in this curve C1, a peak C is observed, which corresponds to the part of the sulphur contained in the pyrite during pyrolysis (hereinafter referred to as "pyrolysed pyrite sulphur" and indicated as

) Is released. Furthermore, the first two peaks a and B of curve C1 correspond to the sulfur contained in thermally labile organic compounds that are vaporizable and thermally cleavable, respectively.

According to the invention, the sulphur content of the pyrolysed pyriteFrom SO measured during the pyrolysis step₂Is determined. According to one embodiment of the invention, the sulfur content of the pyrolized pyrite is

Can be determined from SO recorded during the pyrolysis stage₂The area under the representative peak of pyrolitic pyritic sulphur on the measurement curve (see peak C in fig. 1 a) is divided by the weight of the sample analyzed and determined by pyrolysis sulphur calibration coefficient weighting. The pyrolitic pyrite sulfur content is expressed as a weight percentage, i.e., the weight of pyrolitic pyrite sulfur divided by the weight of the sample and multiplied by 100.

According to one embodiment of the invention, analysisPyrolytic Sulfur content S in samples_PyrolysisCan be determined from SO recorded during the pyrolysis heating process₂The area under the measurement curve is divided by the weight of the analyzed sample and determined weighted by the pyrolysis sulfur calibration coefficient (correspondingly, the sulfur oxide calibration coefficient). These amounts are expressed as weight percent, i.e., the weight of the pyrolysis sulfur divided by the weight of the sample and multiplied by 100.

According to one embodiment of the present invention, the pyrolysis sulfur calibration factor may be determined from at least one reference sample having a known sulfur content, the reference sample being subjected to a pyrolysis heating process. Thereafter, the pyrolysis sulfur calibration coefficient is determined by SO released by the reference sample during the pyrolysis heating process₂Is itself divided by the weight of the reference sample. According to one embodiment of the present invention, the reference sample used to determine the calibration coefficient for pyrolysis sulfur may be natural sulfur.

2. Heating process in an oxidizing atmosphere (oxidation)

According to the invention, the sample is heated according to a predetermined temperature course under an oxidizing atmosphere between a temperature T3 and a temperature T4, the temperature T3 being between 280 ℃ and 320 ℃, preferably 300 ℃, the temperature T4 being greater than or equal to 800 ℃.

According to one embodiment of the invention, the temperature course of heating in an oxidizing atmosphere may consist of a temperature gradient (or heating rate) comprised between 0.1 and 30 ℃/min, preferably between 20 and 30 ℃/min, more preferably equal to 25 ℃/min. According to another embodiment of the invention, the course of the temperature of the heating in the oxidizing atmosphere may comprise at least one quiescent temperature phase during which the temperature is kept constant and at least one temperature gradient (or heating rate), which may be arranged before or after the at least one quiescent phase.

According to one embodiment of the invention, this step may be carried out by means of an oxidation oven, the pyrolysis residue being purged with an air stream.

According to the invention, the amount of carbon monoxide is measured continuously during the heating process in an oxidizing atmosphere. CO and CO during the Oxidation phase₂The measurement of (b) can be performed by an infrared IR spectrophotometer.

According to the invention, the CO and CO are carried out as a result of the heating of the residue from the pyrolysis in an oxidizing atmosphere₂The residual organic carbon content, hereinafter denoted as RC, is determined as a function of the measurements.

According to one embodiment of the invention, the method is based on CO and CO carried out during a heating process in an oxidizing atmosphere₂Measuring, at least:

amount of carbon monoxide of organic origin only (which is subsequently denoted as S4 CO): this quantity corresponds to the quantity of carbon monoxide released between the temperature T3 of the heating process in the oxidizing atmosphere and an intermediate temperature of the heating process in the oxidizing atmosphere, said intermediate temperature being comprised between 600 ℃ and 700 ℃, preferably equal to 650 ℃;

amount of carbon dioxide of organic origin only (which is subsequently denoted as S4CO)₂): this quantity corresponds to the quantity of carbon dioxide measured between the temperature T3 of the heating process in the oxidizing atmosphere and an intermediate temperature of the heating process in the oxidizing atmosphere, said intermediate temperature being comprised between 600 ℃ and 700 ℃, preferably equal to 650 ℃.

According to one embodiment of the invention, the residual organic carbon content RC is determined according to an equation of the type:

according to the invention, the following is also determined:

hydrogen index (subsequently represented by HI), which corresponds to the hydrogen content of the organic substances of the sample. According to the invention, the index is determined at least by the amount of hydrocarbon-based compound measured during the heating process in an inert atmosphere and the CO and CO measured during the heating process in an inert atmosphere and during the heating process in an oxidizing atmosphere₂Is determined by the amount of;

an oxygen index (subsequently represented by OI), which corresponds to the oxygen content of the organic substances of the sample. According to the invention, the index is determined from at least CO and CO measured during the heating process in an inert atmosphere and during the heating process in an oxidizing atmosphere₂Is determined.

According to one embodiment of the invention, it may be determined that:

-hydrogen index HI, obtained from a formula of the type:

wherein S2 corresponds to the amount of hydrocarbon-based compound cracked during heating of the sedimentary rock sample in an inert atmosphere, S2 is determined from the amount of hydrocarbon-based compound Q released during heating in an inert atmosphere, and TOC corresponds to the total organic carbon content, and is determined for this embodiment of the invention according to the following formula: TOC (wt.%) PC + RC.

According to this embodiment of the invention, the amount of hydrocarbon-based compound S2 cracked during the heating of the sedimentary rock sample in an inert atmosphere corresponds to the hydrocarbon-based compound not present in free form in the rock sample studied. The expert is well aware of a method for determining the amount S2 of hydrocarbon-based compounds cracked during heating of a sedimentary rock sample in an inert atmosphere from the amount Q of hydrocarbon-based compounds released during heating in an inert atmosphere, in particular from a pyrogram representing the evolution of the amount Q of hydrocarbon-based compounds released during heating in an inert atmosphere. In fact, the pyrogram typically has a number of peaks: the first peak (generally denoted by S1) corresponds to the hydrocarbon-based compound present in the sample in free form, and the other peaks below correspond to the amount of hydrocarbon-based compound cracked during heating of the sedimentary rock sample in an inert atmosphere. Thus, quantity S2 can be determined from the surface area of the peak in the pyrogram that is different from peak S1;

-an oxygen index OI obtained from the following type of formula:

wherein, S3CO₂Is the amount of carbon dioxide of organic origin measured during the heating process in an inert atmosphere, and TOC is the total organic carbon content defined as described above.

3. Quantification of pyrite sulfur

According to the invention, during this step, the pyrite sulphur content S contained in the sedimentary rock sample studied^PyriteBy pyrolysis of pyrite sulfur according to the formula

And a weighting function p (α, β, γ) (see below, section "below as determined

S of a function of^PyriteExpression (c):

and, according to the present invention,

S^pyriteExpressed as weight percent, i.e., the weight of the pyritic sulfur divided by the weight of the sample and multiplied by 100, and:

the parameter α represents the ratio of the pyrite sulphur released in the pyrolysis stage with respect to its total sulphur and can be considered as the degree of thermal degradation of the pyrite. According to one embodiment of the invention, the parameter α is between 0.40 and 0.46, and preferably equal to 0.43;

the parameter β represents the effect of the mineral substrate on the rate of chalcopyrite sulphur released during the pyrolysis stage. In fact, the mineral matrix reduces the amount of sulphur of the pyrite released during the pyrolysis stage. According to one aspect of the invention, the parameter β may be 0.04 to 0.97, depending on the type of rock from which the sample under investigation is derived. According to an embodiment of the invention, in which the rock sample under investigation is of the clay type, the parameter β may be between 0.04 and 0.7, and preferably equal to 0.38. According to an embodiment of the invention, in which the rock sample under investigation is of the marl type, the parameter β may be between 0.7 and 0.9, and preferably equal to 0.78. According to an embodiment of the invention, in which the rock sample under investigation is of the limestone type, the parameter β may be between 0.85 and 0.97, and is preferably equal to 0.90;

the parameter γ represents the effect of the organic matrix on the rate of pyrite sulphur released during the pyrolysis phase and is predetermined by an equation of the type:

γ＝f(OI，HI)

where f is a function of at least the oxygen index OI and the hydrogen index HI, these indices being determined during step 2 of the process according to the invention.

According to a preferred embodiment of the invention, the function f is a linear combination of the oxygen index OI and the hydrogen index HI, which can be represented by the following type of formula: γ ═ a ═ OI + b ­ HI + c, where a, b, and c are predetermined constants. In fact, the analyses carried out on different samples (see below, section "calibration of constants a, b and c of parameter γ") can confirm the linear nature of the organic matrix influence with respect to the hydrogen index and the oxygen index.

Advantageously, the constant a is between 0.28 and 0.46 and preferably equal to 0.37, and/or the constant b is between-0.005 and-0.007 and preferably equal to-0.006, and/or the constant c is between 4.99 and 6.49 and preferably equal to 5.74. In fact, the analyses carried out on different samples (see below, section "calibration of constants a, b and c of parameter γ") can confirm the linear nature of the organic matrix influence with respect to the hydrogen index and the oxygen index. Advantageously, γ may be 0.34 (wt%) to 74 (wt%).

Apparatus for carrying out the method of the invention

According to one embodiment of the invention, the above steps 1 and 2 can be obtained by means of what has been developed by the applicant and described in detail in patent EP2,342,557(US8,796,035)

Plant (IFP new energy company, france). In practice, the amount of the liquid to be used,

the device at least comprises the following components:

-a furnace for carrying out pyrolysis in a non-oxidizing atmosphere,

means for oxidizing a sulfur-containing effluent obtained from pyrolysis,

for continuous measurement of SO contained in the effluent after oxidation₂A device of a quantity, such as an Ultraviolet (UV) or Infrared (IR) spectrophotometer,

means for transferring the pyrolysis residue to an oxidation oven,

a furnace for carrying out the oxidation in an oxidizing atmosphere,

for continuous measurement of SO contained in said fraction after oxidation₂A device of a quantity, such as an Ultraviolet (UV) or Infrared (IR) spectrophotometer,

means for measuring hydrocarbon-based compounds released during pyrolysis, e.g. a Flame Ionization Detector (FID),

for the reaction of carbon monoxide (CO) and carbon dioxide (CO)₂) The device for performing the measurement, for example, an Infrared (IR) spectrophotometer.

According to an alternative of an embodiment of the method of the invention, the method can also be carried out by a system comprising a single pyrolysis furnace, which can be operated in a non-oxidizing atmosphere and an oxidizing atmosphere, with a device for measuring sulphur dioxide (SO)₂) Of a hydrocarbon-based compound, a device for measuring the amount of a hydrocarbon-based compound, and a device for measuring carbon monoxide (CO) and carbon dioxide (CO)₂) The components of (1) are mated.

Variant 1: quantification of organic sulfur

Described below is a first variant of the process of the invention, which, in addition to the amount of pyritic sulphur present in the sample studied, is also intended to determine the amount of organic sulphur present in this same sample. For this purpose, during the oxidation step 2 of the pyrolysis residue described above, the SO produced by the oxidation of the pyrolysis residue and contained in the oxidation effluent is additionally measured₂. For example, the SO₂The measurement is carried out by a UV or IR spectrophotometer. Thereby obtaining SO released during oxidation₂As a function of, for example, oxidation time and/or temperature.

FIG. 1b shows an example of a curve (denoted by C2), which is SO₂Measurement of quantities (more precisely, from SO)₂The amplitude a measured by a detector, such as an ultraviolet spectrophotometer) as a function of the oxidation time (denoted by T) and also shows the evolution of the oxidation temperature (denoted by T) as a function of the oxidation time. For this example, and for purposes of illustration, temperature T1 is selected to be equal to 300 ℃, temperature T2 is selected to be equal to 650 ℃, temperature T3 is selected to be equal to 300 ℃, and temperature T4 is selected to be equal to 1200 ℃.

It can be observed that the curve C2 includes a plurality of peaks. In particular, on this curve C2, a peak F is observed, which corresponds to the sulphur contained in the sulphate during oxidation (hereinafter referred to as "sulphate sulphur" and indicated as "sulphate sulphur")

) Is released. Likewise, it can be observed that curve C2 shows two first peaks D and E, almost combined, corresponding respectively to the organic sulphur contained in the organic compound (which is thermally refractory or generated during the pyrolysis stage) and to the pyritic sulphur. It can therefore be noted that the SO released during the oxidation phase is recorded₂The two peaks cannot be distinguished and therefore the organic and pyritic sulphur cannot be distinguished.

According to this first variant of the invention, the pyrolysis sulfur S released during pyrolysis_PyrolysisContent of (D) and sulphur oxide S released during the oxidation of the pyrolysis residue_{Oxidation by oxygen}Respectively from SO during a heating process in an inert atmosphere and a heating process in an oxidizing atmosphere₂And measuring to quantify. According to this variant of the invention, the total sulfur content S_{General assembly}Also determined as two contents S_PyrolysisAnd S_{Oxidation by oxygen}The sum of (a) and (b), i.e.:

S_{general assembly}＝S_Pyrolysis+S_{Oxidation by oxygen}，

These amounts are expressed as weight percent (wt%), i.e., the weight of total sulfur divided by the weight of the sample and multiplied by 100.

According to one embodiment of this first variant of the invention, the sample is analyzed for the content of pyrolysis sulfur S_Pyrolysis(phase ofThe sulfur oxide content S_{Oxidation by oxygen}) Can be determined from SO recorded during the pyrolysis heating process (and correspondingly during the oxidative heating process)₂The area under the measurement curve is divided by the weight of the analyzed sample and determined weighted by the pyrolysis sulfur calibration coefficient (and correspondingly, the sulfur oxide calibration coefficient). These contents are expressed as weight percent, i.e., the weight of the pyrolysis sulfur (and, correspondingly, the sulfur oxide) divided by the weight of the sample and multiplied by 100.

According to this first variant of the invention, the organic sulphur content S contained in the rock sample studied^{Organic compounds}At least the total sulfur content S_{General assembly}And the sulfur content S of the pyrite^PyriteThe difference between them.

According to a first embodiment of this first variant of the invention, in which the temperature T4 at the end of the oxidation is between 800 ℃ and 900 ℃, the organic sulphur content S contained in the sample is^{Organic compounds}Can be determined according to the following type of formula:

S^{organic compounds}＝S_{General assembly}–S^Pyrite。

According to a second embodiment of this first variant of the invention, in which the temperature T4 at the end of the oxidation is between 1150 ℃ and 1250 ℃, preferably 1200 ℃, the organic sulphur content S contained in said sample^{Organic compounds}This may be determined in the following manner:

from SO recorded during the oxidation phase₂The area under the representative peak of the measurement curve for sulfate sulphur is divided by the weight of the analytical sample and weighted by a sulfur oxide calibration coefficient (see step 3 above for determining this calibration coefficient), the sulfate sulphur content being determined

Carrying out quantification;

-organic sulphur content S^{Organic compounds}Is determined by the following type of formula:

indeed, for variants of this embodiment, it is possible to distinguish betweenCorresponds to the peak released during the oxidation of the sulphur contained in the sulphate salt which occurs at high temperature

(see peak F in FIG. 1 a). According to this second embodiment of the invention, the determination of the organic sulphur content is more accurate.

Variant 2: calibration of parameters alpha, beta and gamma

According to one embodiment of the invention, the parameters α and/or β and/or γ as defined above may be calibrated before or during the implementation of the method of the invention, for example before step 1, step 2 or step 3 described above, or in parallel with step 1 and/or 2.

Calibration of the parameter α

According to an embodiment of the invention, the parameter α may be calibrated by estimating the ratio of the released pyrite sulphur during the pyrolysis phase with respect to the total sulphur from at least one pure pyrrhotite sample. According to an embodiment of the present invention, "pure" pyrite may be obtained by cleaning natural pyrite by chemical attack to remove its impurities.

An example of parameter alpha calibration is described below. Four samples (represented by E1, E2, E3, E4, respectively) of different weights (2 mg, 3mg, 4mg, and 8mg, respectively) from a single sample of pure pyrrhotite were passed through eachThe plant (new energy company IFP, france) performs pyrolysis. In particular for this example of parameter alpha calibration, each sample is placed atIn the pyrolysis furnace of the apparatus, the sample is then heated at 300 ℃ to 650 ℃ under a nitrogen flow of 150 ml/min with a temperature gradient of 25 ℃/min. Subsequently, the sulphur-containing effluent released by each of the pure pyrrhotite samples studied was entrained by the nitrogen flow

The combustion chamber (oxidation furnace) of the plant, where the sulfur-containing effluent is converted to SO in the form of a continuous stream₂Then SO₂Is brought into SO₂A detector, here by

SO of the plant₂The detector continuously quantifies it. Then, the solid residue of each sample of pyrrhotite obtained after the pyrolysis process was completed was placed in

In the oxidation oven of the apparatus, the sample is then heated at 300 ℃ to 850 ℃ with a temperature gradient of 20 ℃/min under a flow of air of 100 ml/min. Released SO₂The effluent is carried over to SO₂A detector where the effluent passes

SO of the plant₂The detector performs continuous quantification.

FIG. 2 shows SO released by samples E1, E2, E3, and E4 during the pyrolysis stage described above₂The recording of the quantity (more precisely the amplitude) over time t. The curve T also shown in this figure 2 corresponds to the evolution of the temperature to which each sample studied was subjected during this same pyrolysis phase. Thus, in particular in this figure it can be observed that there are representative peaks of thermal degradation of pyrite during the pyrolysis phase, analyzed in respective different weights. The pyrolysed sulphur content (pyrolysed pyrites sulphur content) of the sample of pyrogenic pyrite is calculated by: the sulfur content of the reference sample was multiplied by the area under each curve E1, E2, E3, and E4, divided by the weight of the sample, and the pyrolytic sulfur content of the pyrrhotite sample was related to the SO released by the reference sample (e.g., natural sulfur) during the pyrolytic heating process₂The area under the measurement curve itself divided by the weight of the reference sample. The ratio between the sulphur content of the pyrolysed pyrite and the total sulphur content of the pyrite is calculated. The results show that: the weight ratio of the released pyritic sulphur during pyrolysis was 0.43 ± 0.03 wt%, whatever the weight analyzed. End of pyrolysis processThe remaining proportion of pyritic sulphur (0.57 ± 0.03 wt%) is then released during the oxidation phase.

Thus, calibration as described above may determine that the parameter α is 0.40 to 0.46, and that it is equal to 0.43 on average.

Calibration of parameter β

According to one embodiment of the invention, the parameter β, which represents the effect of the mineral matrix on the amount of pyrite sulphur released during the pyrolysis phase, can be calibrated from at least one mixture of pyrite and at least one mineral type, which is representative of the rock sample to be studied by the method of the invention.

Examples of calibrating the parameter β for various mineral types are described below. For an example of this parameter beta calibration, a mixture was prepared from the following two main groups of minerals:

clay/silicate-based minerals, such as:

silica (maple white dew sand, france), the mixture prepared with silica being the reference mixture, since silica is known to be non-reactive;

kaolinite (type: CMS KGa 1 b);

montmorillonite (model: Mx 80);

illite (wolley clay, france): since this sample naturally contains carbonate, it was decarbonated with hydrochloric acid;

carbonate-based minerals, such as:

calcite (france);

dolomite (eugay, spain);

siderite (peru).

The following mixtures were then prepared:

-2 mg pyrite +98 mg of each clay/silicate-based mineral;

-2 mg pyrite +58 mg of each carbonate-based mineral;

2mg pyrite +98 mg clay (all clay/silicate based minerals equal parts 1/4; 1/4; 1/4; 1/4);

2mg pyrite +58 mg carbonate (equal parts 1/3; 1/3; 1/3 for all carbonate-based minerals);

various ratios of clay and carbonate of 2mg pyrite +58 mg, namely:

93% clay and 7% carbonate;

69% clay and 31% carbonate;

51% clay and 49% carbonate;

26% clay and 74% carbonate.

Then pass through

The apparatus (IFP new energy company, france) subjects these different samples to steps 1 and 2 as described above. More specifically, each sample was placed on

In the pyrolysis furnace of the apparatus, the sample is then heated at 300 ℃ to 650 ℃ under a nitrogen flow of 150 ml/min with a temperature gradient of 25 ℃/min. According to one embodiment of the invention, the sulfur-containing effluent released by each sample is entrained by a nitrogen stream

The combustion chamber (oxidation furnace) of the plant, where the sulfur-containing effluent is converted to SO in the form of a continuous stream₂Then SO₂Is brought into continuous dosing

SO of the plant₂A detector. Then, the solid residue of each sample obtained after the pyrolysis process was completed was placed inIn the oxidation oven of the apparatus, the sample is then heated at 300 ℃ to 850 ℃ with a temperature gradient of 20 ℃/min under a flow of air of 100 ml/min. Released SO₂The effluent is carried over to SO₂A detector where the effluent passes

SO of the plant₂The detector performs continuous quantification.

The term "influence of the mineral matrix" is then given in terms of size according to a formula of the type:

wherein the content of the first and second substances,

is the pyrolysed pyrite sulphur released by the reference sample (consisting of pure pyrogenic pyrite and silica) and

is the pyrolysed pyrite sulphur released from the mixture under investigation (pure pyrogenic pyrite plus mineral or mineral mixture). To estimate the size, the size is estimated relative to a reference sample

And the mixture under investigation

To determine the sulfur content of the pyrolized pyrite.

FIG. 3a shows the effect E of the mineral matrix in the case of clay/silicate-based minerals and carbonate-based minerals_{Mineral substance}Representative histograms as a function of the mixture category studied, more precisely, for the following mixture categories:

-M1: a mixture consisting of pyrite and quartz (reference sample);

-M2: a mixture consisting of pyrite and kaolinite;

-M3: a mixture consisting of pyrite and illite;

-M4: a mixture consisting of pyrite and montmorillonite;

-M5: a mixture consisting of pyrite and calcite;

-M6: a mixture consisting of pyrite and dolomite;

-M7: a mixture consisting of pyrite and siderite.

FIG. 3b shows the average effect E of clay, carbonate and intermediate formation (intermedia formats) on the ratio of sulfur in pyrite released during pyrolysis for the following mixtures_{Mineral substance}The mixture is:

-M8: a mixture consisting of 100% clay;

-M9: a mixture consisting of 93% clay and 7% carbonate;

-M10: a mixture consisting of 69% clay and 31% carbonate;

-M11: a mixture consisting of 51% clay and 49% carbonate;

-M12: a mixture consisting of 26% clay and 74% carbonate;

-M13: mixture consisting of 100% carbonate.

Fig. 3a and 3b also show error bars for each histogram bar.

These error bars were obtained by estimating the standard deviation established by repeated analysis as described above.

Thus, the results obtained by subjecting the various mixtures described above to the method of calibrating the parameter β described above demonstrate that the mineral matrix can reduce the rate of sulphur in the pyrite released during the pyrolysis stage. However, this effect varies greatly depending on the type of mineral present. The relative reduction of the rate of sulphur released during pyrolysis of pyrite ranges from 0% to 40% in the presence of clay/silicate-based minerals, and from 60% to 98% in the presence of carbonate-based minerals (see figure 3 a). The average effect of clay was 6% while the average effect of carbonate reached 93% (see figure 3 b). Between these two extremes, the influence of the mineral matrix E is observed_MThe evolution as a function of the ratio of clay and carbonate in the mixture increases (see figure 3 b).

FIG. 3c shows the effect E of the mineral matrix_{Mineral substance}As mineral carbon [ hereinafter, mineral C (MinC) ]]Can be, for example, with

The parameters measured by the apparatus (IFP New energy Co., France) and this is an indicator of the carbonate content of the mixture. In this figure it can be observed that mineral C varies in the range of 0 to 12 wt%, which corresponds to 0 to 100 wt% calcite equivalent. With this parameter, three lithology types can be defined: clay, marl and limestone. Region (A) in FIG. 3C represents a clay region in which the carbonate-calcite equivalent content is from 0% to 30% by weight (0. ltoreq. mineral C clay<3.6 wt%). In this clay formation zone, the influence of the matrix on the amount of sulphur of the pyrite released in the pyrolysis stage is 6% to 70%, with an average of 38%. Region (B) in FIG. 3C represents a marlite region having a carbonate-calcite equivalent content of 30% to 70% (3.6 wt. ≦ mineral C marlite<8.4 wt%). In the marl formation zone, the matrix has an average influence value on the amount of sulphur of the pyrite released during the pyrolysis stage ranging from 70% to 87%, with an average of 78%. Region (C) in FIG. 3C represents a limestone region having a carbonate-calcite equivalent content of 70% to 100% (8.4 wt% mineral C limestone 12 wt%). In the limestone formation zone, the matrix has an average influence value on the amount of sulphur of the pyrite released in the pyrolysis stage ranging from 87% to 94%, with an average of 90%.

Depending on the type of sedimentary formation, therefore, the parameter β ranges between 0.06 and 0.94, and more specifically,

-in the case of clays: the value of the parameter β is on average equal to 0.38;

-in the case of marl: the value of the parameter β is on average equal to 0.78;

-in the case of limestone: the value of the parameter β is on average equal to 0.90.

Calibration of constants a, b and c of parameter γ

This step can be carried out within the scope of a preferred embodiment of the method of the invention, wherein the parameter γ is written in the form:

γ＝a*OI+b*HI+c，

where a, b, and c are predetermined constants.

According to one embodiment of the invention comprising the step of calibrating the constants a, b and c of the parameter γ, it is possible to prepare a mixture consisting of pyrite and different types of organic matter, each generally expressed as:

-type I: lake organic matter, such as "green river shale" [ new world (Eocene, USA ];

-type II: marine organic matter, such as "thin shale" of the paris basin [ toalarch (Toarcian), france ];

-type II: marine organic matter from ODP 959 wells, [ conian-Santonian (connician-Santonian), ivory coast-garner ];

-oxidized form II: marine organic matter, such as "thin shale" of the paris basin [ toartician (Toarcian), france ], was artificially oxidized according to the method described in the literature Landais et al, 1991;

-type IIS: marine organic matter rich in organic sulfur, such as "phosphorus Formation" (U.S.);

-type III: terrestrial organic materials such as "Calvert formations" (Calvert Bluff Formation) (ancient new world, usa);

-oxidized form III: terrestrial organic materials, such as the "Calvert Bluff Formation" (Calvert Bluff Formation) (ancient times, usa), are artificially oxidized according to the method described in Landais et al, 1991;

-a mixture of forms II and III: a mixture of marine and terrestrial organic matter, such as "thin shale" of the paris basin (Toarcian, france), and such as "Calvert Bluff Formation" (ancient new world, usa).

The term "influence of the organic matrix" is then given in terms of size according to a formula of the type:

wherein the content of the first and second substances,

is a pyrolysed pyrite sulphur obtained after analysis of a mixture formed from pyrite and organic matter, as described in step 1 above, andis the expected value for the pyrolized pyritic sulfur of the mixture. The theoretical reference value is calculated as follows:

by passing

The apparatus (IFP New energy Co, France) analyzed each organic matter sample individually to quantify its sulphur content of the pyrolysed pyrite (as described in step 1 above);

by passingThe plant (IFP new energy company, france) analyzes pyrite individually to quantify its pyrolysed pyrite sulfur content (as described in step 1 above);

-adding the pyrite sulphur from the pyrolysis of pyrite and the pyrite sulphur from the pyrolysis of organic matter in a ratio according to the pyrite/organic matter ratio.

Further, each sample as described above was passed as described in step 2 above

The apparatus (IFP New energy Co., France) determines the hydrogen index HI and the oxygen index OI. In particular, for this purpose, it is preferred that,

-the pyrolytic organic carbon content PC is determined by the formula:

-the residual organic carbon content RC is determined by the following formula:

the oxygen index OI is determined by the following formula:

-the hydrogen index HI is determined by the following formula:

the influence E on the organic substrate is then carried out as a function of the oxygen index OI and the hydrogen index HI and of the constants a, b and c of the parameter γ as defined above_{Organic compounds}(iii) relevant multivariate regression, and determining the form of said function expressed as γ ═ a × OI + b × HI + c. The linear regression thus described makes it possible to obtain the following formula for the parameter γ representing the influence of the organic matrix:

V＝0.37*OI-0.006*HI+5.74。

fig. 4 shows the comparison between the values γ thus determined by regression (continuous straight line) and the values determined by measurement of the various samples as described above (diamonds). It is possible to observe the values obtained by gamma and the E determined by measurement_{Organic compounds}A good correlation between the values (linear regression coefficient R2 of 0.77) indicates that the effect of organic species can be reliably predicted from the oxygen index OI and the hydrogen index HI. Furthermore, on the basis of these experiments on various types of samples, the following error bars are defined for each constant:

-a＝0.37±0.09

-b＝-0.006±0.001

-c＝5.74±0.75

further, it is known that generally 0. ltoreq. HI (mg HC/g TOC)). ltoreq.900 and 0. ltoreq. OI (mg CO)₂TOC ≦ 200, γ may range from 0.34 wt% (HI 900; OI 0) to 74 wt% (HI 0; OI 200).

Determining expressions of weighting functions

The weighting function p (α, β, γ) according to the method of the invention is different from that of patent application FR17/59447 (application number). The reason for the expression of the weighting function of the method of the invention is detailed below.

Denotes a pyrolitic pyrite sulfur content, which is reduced by the presence of mineral and organic substrates. Thus, in the first step, it is recommended to correct the sulphur content of the pyrolysed pyrite for mineral and organic influences

Thus, this allows quantification of total pyrolysed pyrite sulfur

Subsequent derivation of Total pyrite Sulfur S^Pyrite。

Correction of mineral effects Corr beta：

Mineral impact β represents the rate of pyrolitic pyritic sulphur remaining in the mineral matrix. Thus, knowing the effect β of the mineral matrix, it can be found that pyrolysing pyritic sulphur without this mineral matrix effect

The formula for the mineral impact can be written in the following way:

corr β is then defined according to the following formula, which represents the amount of pyrolysed pyrite sulfur remaining in the mineral matrix:

correcting organic effects CorrE_{Organic compounds}：

The organic effect γ represents the ratio of pyrolized pyritic sulfur remaining in the organic matrix. Thus, knowing the effect γ of the organic matrix, it was possible to find pyrolysed pyritic sulphur without the effect of the organic matrix

The formula for the organic effect can be written in the following way:

CorrE is then defined according to_{Organic compounds}It represents the amount of pyrolitic pyritic sulphur remaining in the organic matrix:

total pyrolysis pyrite sulfur

Is calculated by

Then, in the following manner

(reduced pyrolysis sulfur content affected by the presence of mineral and organic substrates), the sum of Corr β (amount of pyrolysis pyritic sulfur retained in mineral substrate) and Corr γ (amount of pyrolysis pyritic sulfur retained in organic substrate) gives the total pyrolysis pyritic sulfur

Total pyrite sulfur S^PyriteIs calculated by

Total pyrite sulfurS^PyriteFrom total pyrolysis of pyrite sulphur

And parameter alpha (total pyrolysed pyrite sulfur)

Sulfur S relative to total pyrite^PyriteRatio of (d) to calculate:

thus, the following expression of the weighting function is derived from the following, which makes it possible to derive from the measured pyrolitic pyrite sulphur

To determine the total pyrite sulfur S^Pyrite：

Application examples

The following application examples are intended to evaluate the quality of the results obtained by carrying out the process of the invention. To this end, various mixtures formed by adding 9 sedimentary rock samples containing only known amounts of organic sulfur to known weights of pyrite were produced. Rock samples were taken from three different strata [ "Orbamous", "phosphor (phosphor)" and "Limagne (Ligagne)" ], and were taken from different levels of these strata. The properties of these nine sedimentary rock samples are summarized in the first nine rows of tables 1a and 1b below. To these 9 samples different weights of pyrite were added according to the characteristics summarized in lines 10 and 11 of tables 1a and 1b below. In this way, mixtures of 14 "pyrite + obax" types (this type is subsequently denoted as EXA), mixtures of 6 "pyrite + phosphide" types (this type is subsequently denoted as EXB) and mixtures of 8 "pyrite + rimantane" types (this type is subsequently denoted as EXC) were produced.

Then, on the one hand, by the process of the present invention and, on the other hand, by the process according to the prior art described in patent application FR17/59447, the pyritic sulphur content and the organic sulphur content of each of these mixtures are determined.

The method of the invention comprises

Plant (france IFP new energy company). More specifically, each mixture was placed in

In the pyrolysis furnace of the apparatus, the mixture is then heated at 300 ℃ to 650 ℃ under a nitrogen flow of 150 ml/min with a temperature gradient of 25 ℃/min. According to one embodiment of the invention, the sulfur-containing effluent released by each sample is entrained by a nitrogen streamThe combustion chamber of the plant (also called oxidation furnace), where the sulfur-containing effluent is converted to SO in the form of a continuous stream₂Then SO₂Is brought into continuous dosing

SO of the plant₂A detector. After the pyrolysis has ended, the residues of the mixture are transferred from the pyrolysis furnace to a reactorThe oxidation oven of the apparatus, then the sample is heated at 300 ℃ to 850 ℃ or 1200 ℃ according to the embodiment with a temperature gradient of 20 ℃/min under a flow of air of 100 ml/min. SO released by the oxidation₂The effluent is brought into pairWhich is continuously dosedSO of the plant₂A detector. The total sulfur content, the pyrite sulfur content, and the organic sulfur content of each mixture were determined by performing the inventive method as described above.

FIGS. 5a, 5b and 5c show the total sulfur content (INV TS), the pyrite sulfur content (INV S) obtained by the method according to the invention, respectively_Pyrite) And organic sulfur content (INV S)_{Organic compounds}) Respectively as the total sulfur reference content (VR TS), the pyrite sulfur reference content (VRS) of each type EXA mixture (i.e., 14 "pyrite + Oxburgs" mixtures), each type EXB mixture (i.e., 6 "pyrite + phosphor-containing" mixtures), and each type EXC mixture (i.e., 8 "pyrite + Limnite" mixtures)_Pyrite) And organic sulfur reference content (VR S)_{Organic compounds}) As a function of (c).

Very good correlations (slope of correlation close to 1) between the total sulphur content, the pyritic sulphur content and the organic sulphur content determined using the method of the invention and the total sulphur reference content, the pyritic sulphur reference content and the organic sulphur reference content can be observed in fig. 5a, 5b and 5 c. This confirms the accuracy of the determination of the sulfur content and organic sulfur content of the pyrite in the sample by the method of the present invention.

FIGS. 5d and 5e show the sulphur content (AA S) of the pyrite obtained by the process according to the prior art, respectively_Pyrite) And organic sulfur content (AA S)_{Organic compounds}) As the pyrite sulfur reference content (VR S) for each EXA-type mixture (i.e., 14 "pyrite + Oxburgs" mixtures), each EXB-type mixture (i.e., 6 "pyrite + phosphor-containing" mixtures), and each EXC-type mixture (i.e., 8 "pyrite + Limnite" mixtures), respectively_Pyrite) And organic sulfur reference content (VR S)_{Organic compounds}) As a function of (c).

In fig. 5d and 5e, poor correlations between the content of pyritic sulphur and organic sulphur determined using the method according to the prior art and the reference content of pyritic sulphur and organic sulphur can be observed.

Therefore, the present invention can significantly improve the accuracy of determining the sulfur content of the pyrite contained in the sedimentary rock sample, and thus significantly improve the accuracy of determining the organic sulfur content contained in the sedimentary rock sample.

TABLE 1a

TABLE 1b