CN110412106B - Method for performing oil source comparison by using molybdenum isotope - Google Patents
Method for performing oil source comparison by using molybdenum isotope Download PDFInfo
- Publication number
- CN110412106B CN110412106B CN201910608051.5A CN201910608051A CN110412106B CN 110412106 B CN110412106 B CN 110412106B CN 201910608051 A CN201910608051 A CN 201910608051A CN 110412106 B CN110412106 B CN 110412106B
- Authority
- CN
- China
- Prior art keywords
- sample
- molybdenum
- crude oil
- oil
- hno
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/34—Purifying; Cleaning
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/62—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
- G01N2001/2866—Grinding or homogeneising
Abstract
The invention discloses a method for performing oil source comparison by using molybdenum isotopes. The method comprises the following steps: s100, separating and enriching molybdenum elements in the crude oil; s200, separating and enriching molybdenum elements in the source rocks; s300, testing and analyzing the content of the molybdenum element; s400, detecting and analyzing the stable isotope composition of molybdenum; s500, establishing delta through analysis of molybdenum isotopes in known different deposition environments, different maturity hydrocarbon source rocks and crude oil and hydrocarbon source rocks with different properties97Mo (‰) -oil reservoir type identification index chart; s600, determining the source and cause of the unknown oil source according to the established identification index chart. The invention utilizes molybdenum isotope to judge and identify oil gas source and cause, and provides technical and theoretical guidance for oil gas exploration target determination by rapidly determining oil gas cause.
Description
Technical Field
The invention belongs to the technical field of oil-gas exploration, and particularly relates to a method for performing oil source comparison by using molybdenum isotopes.
Background
Organic geochemistry research mainly focuses on composition, structure, origin and evolution of organic matters in geologic bodies, and in the field of oil and gas exploration, especially the comparison between oil and gas causes and oil sources is of great importance, and the research is highly valued because the exploration target evaluation and well location optimization, the scale and distribution rule of oil and gas reservoirs and the like are concerned. The conventional method is to use the indexes such as biological markers, carbon isotopes and the like to determine the cause and source of oil gas, and the method is successfully applied in most areas or oil gas fields. However, in some complex areas, such as the Tarim basin, whether the oil and gas are from the Han-Wu system or the Ordovician system, controversy exists. Therefore, it is necessary to develop a new index system for determining the cause of oil and gas.
Molybdenum is easy to adsorb and chelate by organic matters, so that the molybdenum is easy to enrich in hydrocarbon source rocks, enters oil gas in the hydrocarbon formation process and migrates along with the oil gas, and the molybdenum has important tracing value along with the processes of organic matter formation in deposition, thermal maturity hydrocarbon generation, migration aggregation and the like. The molybdenum stable isotope information in the hydrocarbon source rock and the oil gas in different basin areas, different cause types and different thermal evolution stages has certain difference values, and the oil gas cause can be judged and identified by using the difference values to guide oil gas exploration.
Disclosure of Invention
Based on the above background art, the present invention provides a method for performing oil source comparison by using molybdenum isotopes. The method fills the gap of identifying the source and the cause of the oil gas by using the molybdenum isotope at present, and provides technical and theoretical guidance for determining the oil gas exploration target by quickly determining the cause of the oil gas.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a method for performing oil source comparison by using molybdenum isotopes, which comprises the following steps:
s100, separating and enriching molybdenum elements in the crude oil;
s200, separating and enriching molybdenum elements in the source rocks;
s300, testing and analyzing the content of the molybdenum element;
s400, detecting and analyzing the stable isotope composition of molybdenum;
s500, establishing delta through analysis of molybdenum isotopes in known different deposition environments, different maturity hydrocarbon source rocks and crude oil and hydrocarbon source rocks with different properties97Mo (‰) -oil reservoir type identification index chart;
the mass fractionation of molybdenum is that molybdenum isotopes with different mass numbers are separated and enriched in different reactants in an oxidation-reduction reaction; non-mass fractionation is the fractionation of molybdenum isotopes in some reactions that is largely unaffected by mass factors.
S600, determining the source and the cause of the unknown oil source according to the established identification index chart, and guiding exploration deployment.
In the above methods, the source rock and crude oil are respectively from oil field cored well core or peripheral outcrop rock samples, petroleum samples of normal production wells, including crude oil, rock samples, etc. of different cause types and different maturity, and of different properties.
Preferably, said delta97Mo (‰) -oil deposit type identification index plate, delta of coal crude oil97Mo ranges from 1.04 to 1.58 per mill, delta of coal-series hydrocarbon source rock97Mo ranges from 0.78 to 1.41 per mill, delta of sea-phase crude oil97Mo ranges from 0.17 to 0.64 per mill, delta of marine hydrocarbon source rock97Mo ranges from 0.01 to 0.77 ‰, delta of continental-phase crude oil97Mo ranges from-0.46 to-0.14 per mill, delta of continental-phase hydrocarbon source rock97Mo (mill) ranges from-0.79 per mill to-0.08 per mill.
The following is a detailed description of each step:
s100, separating and enriching molybdenum elements in the crude oil.
Preferably, S100 specifically includes:
s110, preparing a crude oil sample;
s120, separating and purifying molybdenum in the crude oil sample.
Further preferably, the preparation of the S110 crude oil sample comprises:
s111, taking fresh crude oil, sequentially adding petroleum ether and ethanol for mixing and dissolving, and heating to obtain a primary sample; wherein, petroleum ether and ethanol are organic solvents with good effect of dissolving organic matters in crude oil.
Preferably, the proportions of crude oil, petroleum ether and ethanol are: (6-8 g): 14-16 mL: 14-16 mL. More preferably (6-8 g): 15mL of: 15 mL.
Preferably, the heating temperature is 75-85 ℃ and the heating time is 11-13 hours. More preferably, the heating is carried out at a temperature of 80 ℃ for a period of 12 hours.
For example, in the embodiment of the present invention, the step specifically includes:
taking about 20g of a fresh crude oil sample from an oil outlet well head of a production well site; weighing 6-8 g of fresh crude oil in a quartz beaker, adding 15mL of petroleum ether, shaking up to mix the crude oil and the petroleum ether basically, adding 15mL of absolute ethyl alcohol, and heating for 12 hours at 80 ℃ on an electric hot plate after shaking up.
And S112, weighing the fresh crude oil again, and repeating the process of S111.
S113, standing the primary samples prepared twice at normal temperature, respectively extracting upper oil samples, mixing, adding absolute ethyl alcohol, shaking up, and heating to prepare a crude oil sample to be tested.
Preferably, the mixture is kept still for 22-24 hours and heated at 60-70 ℃ for 16-18 hours. More preferably, the mixture is left to stand for 24 hours and heated at 60 ℃ for 18 hours.
The reason why the mixing is carried out in two times in this example is to allow the organic component to be sufficiently dissolved and to shorten the heating time.
Further preferably, the separation and purification of the molybdenum element in the S120 crude oil sample comprises:
1) digesting a crude oil sample;
2) dissolving the digested sample in HNO3And HF, heating for reaction until the sample is completely dissolved; evaporating to dryness to form wet salt after the reaction is finished, and then using HNO3Removing redundant HF, finally adding HCl, and evaporating to dryness to obtain powder;
3) purifying a Mo sample by using a Chelx100 resin and TSK-8HG resin double-column method, separating molybdenum element by using 7mol/LHCl as a medium, evaporating a molybdenum solution obtained by purification to dryness, and converting the molybdenum solution into 2% HNO3Medium to be tested.
Preferably, the digestion solvent is dichloromethane, and the digestion reagent is HNO3-H2O2And (4) digesting the system.
In S120, the crude oil molybdenum element is separated by dissolving a sample by using an organic solvent dichloromethane, CH2Cl2Can fully dissolve petroleum, make each component in the crude oil disperse uniformly, fully contact with a digestion reagent to improve the oxidation efficiency, obtain a monitoring result with better repeatability, and select HNO as the digestion reagent3-H2O2Digestion system to remove H from crude oil2S and organic impurities.
For example, S120 in the embodiment of the present invention specifically includes:
1) accurately weighing 1g of crude oil sample in a high-pressure closed digestion tank, and adding 2mL of CH2Cl2Fully dissolving the crude oil, and then adding 5mL of concentrated HNO3-H2O2Digesting the reagent at the high temperature of 200 ℃ for 5min, cooling, then using high-purity water to fix the volume to 30mL, and placing the fixed-volume sample in a drying cabinet at the temperature of 600 ℃ for 24h to remove organic matters.
2) 2mL of 2mol/L HNO was added3And 4mL of 0.5mol/L HF, covering a cover, dissolving the sample, and putting the sample into an oven for reacting for 48 hours at 220 ℃; the steps can be repeated until the sample is completely dissolved, the sample is taken out after cooling, and the sample is dried on a heating plate at 200 ℃ until the sample is in a wet salt state; then 2mL of 2mol/L HNO is added3And (3) removing redundant HF, repeatedly removing the HF for 3 times, finally adding 5mL of 6mol/L HCl, and evaporating to dryness to obtain powder. The volatile components in the sample are volatilized, and organic matters are removed.
3) Purifying the Mo sample by using a Chelx100 resin and TSK-8HG resin double-column method, separating molybdenum element by using 7mol/L HCl as a medium, evaporating the purified molybdenum solution to dryness, and converting the molybdenum solution into 2% HNO3Medium, to be tested, waiting for elemental content determination and isotope analysis of S300 and S400. Conversion to 2% HNO3The medium is specifically as follows: adding 8mol/L HNO3About 20. mu.L of sample was converted to 2% HNO3A medium; conversion of the sample to 2% HNO3The medium is used to meet the acidic medium requirement of instrument test.
S200, separating and enriching molybdenum elements in the source rocks.
Preferably, S200 specifically includes:
s210, selecting and crushing a rock sample to obtain sample powder of the hydrocarbon source rock;
s220, separating and purifying molybdenum element in the sample powder.
Preferably, S210 includes:
s211, selecting a rock sample;
and S212, crushing the sample, and grinding to obtain sample powder.
In the present embodiment, the process of preparing the sample powder at S210 includes:
1) selecting a rock sample: and (4) observing whether the surface of the rock sample is fresh or not and the weathering degree, and taking a photo to describe the information of the sample and inputting the information into a sample table. Wrapping the sample with clean cloth, covering the top and bottom surfaces of the sample with a wood board, hammering the wood board with a steel hammer to break the sample, selecting about 5g of sample particles with fresh four sides, no quartz vein and no wormhole structure after the sample is broken, clamping the sample with a disposable clamp, putting the sample into a sample bag, and recording and taking the number.
2) Sample crushing: selecting two identical grinding tanks, placing one of the grinding tanks into an agate ball, a) adding quartz sand into the grinding tank with the agate ball to cover the agate ball in half, screwing the two grinding tanks, placing the grinding tanks on a sample crusher, fixing the grinding tanks, rotating the grinding tanks at a speed of 1300r/min for 3 minutes, taking down the quartz powder after the rotation is finished, observing whether the inner surfaces of the grinding tanks are clean, and continuing the step if the inner surfaces of the grinding tanks are not clean. b) Clamping a sample in a sample bag by using a disposable pliers, putting the sample into a grinding tank, screwing the sample on a sample crusher, fixing the sample at a speed of 1300r/min, rotating the sample for 3 minutes, taking down the sample powder after the rotation is finished, pouring the sample powder onto disposable paper, wiping the inner surface of the grinding tank and an agate ball by using a disposable paper towel to pour the sample powder out as much as possible, and pouring the sample powder into the sample bag to record a serial number. c) Washing the grinding tank, and repeating the step a) for 2-3 times (for sure to ensure that the inner surface of the grinding tank is clean). Then the next sample crushing work is carried out in sequence.
Preferably, the separation and purification of the molybdenum element in the S220 sample powder comprises:
1) adding HCl into the sample powder in a high-pressure digestion tank to perform digestion reaction; after the reaction is finished, centrifugally cleaning the mixture by using deionized water;
2) drying the centrifugally cleaned sample, and grinding into powder;
3) purifying the Mo sample by using Chelex-100 resin to separate out the molybdenum element;
firstly, 2mol/L of HNO is used3Completely dissolving the sample powder with 6mol/L HNO3The solution and deionized water are used for cleaning the resin, then the mixed solution of 0.02mol/L HCl and 0.2mol/L HF is used for washing the same amount of the isomorphin of the molybdenum, and 8mol/L NH is used3Solution collection ion exchange resinEvaporating the molybdenum solution obtained by purification to dryness and dissolving the molybdenum solution in nitric acid, and finally dissolving the sample in 0.3mol/L HNO3The solution is to be tested, and the elemental content determination and isotope analysis of S300 and S400 are waited.
In the embodiment of the present invention, the separation and purification of molybdenum in the S220 sample powder includes:
1) weighing about 1g of sample powder in a 20mL high-pressure digestion tank, adding 20mL of 3mol/L HCl by using a liquid transfer gun, covering a cover, fully reacting, standing for 24h, then washing by using deionized water, putting into a 3200r/min centrifugal machine for centrifugation for ten minutes after washing, washing for at least 4 times, and washing until the sample powder is no longer acidic. This step selects HCl to dissolve the sample because many carbonates, hydroxides, various sulfides, etc. can be dissolved by hydrochloric acid.
2) Putting into a 75 ℃ oven for reaction for 12-20h, drying, grinding into powder by a weighing spoon, and weighing 6 mg.
3) Purifying Mo sample with chelating resin Chelex-100 to separate out molybdenum element, and preparing 2mol/L HNO3Completely dissolving the sample powder with 6mol/L HNO3Washing ion exchange resin with solution and deionized water, washing the same amount of molybdenum allelotide with mixed solution of 0.02mol/L HCl and 0.2mol/L HF, and then washing with 8mol/L NH3The solution is collected to molybdenum element in ion exchange resin, is evaporated to dryness in a drying oven at 150 ℃ and then 2mol/L HNO is used3Dissolving the solution, and finally dissolving the sample in 0.3mol/L HNO3The solution is to be tested, and the elemental content determination and isotope analysis of S300 and S400 are waited.
And S300, testing and analyzing the content of the molybdenum element.
And in S300, a multi-receiving inductively coupled plasma mass spectrometer MC-ICP-MS is used for measuring the content of the molybdenum element.
The test of the content of the molybdenum element specifically comprises the following steps:
1) and drying the sample in an oven at the temperature of more than 150 ℃ for 2 hours to remove the adsorbed water on the surface of the sample.
2) 5g of sample is accurately weighed, the sample is placed in a high-temperature furnace at 800 ℃ for ashing treatment, and 5mL of nitric acid is added into the treated residue. Placing on an electric heating plate, keeping the temperature at 250 ℃, and heating for dissolving. If turbidity occurs, adding proper amount of 0.5mol/L sulfuric acid to remove.
3) The Ca ions in the sample can be removed by adding a proper amount of 2mol/L ammonium chloride.
4) Adding 5mL of each of high-purity HCl and high-purity HF, covering and sealing a steel sleeve, and putting the mixture into an oven at 200 ℃ for constant temperature for 48 hours. After cooling, the mixture was evaporated to dryness on a hot plate, and 3mL of high purity HCl was added and evaporated to a wet salt state (to remove residual HF).
5) The total molybdenum content was then determined by performing a total digestion in diaminoethane tetraacetate and making the solution acidic. And (3) determining the content of the iron element by using the digested sample, and determining by using a multi-receiving inductively coupled plasma mass spectrometer MC-ICP-MS.
And S400, detecting and analyzing the stable isotope composition of the molybdenum.
Preferably, the stable isotope composition of molybdenum is analyzed in S400 using a multi-receiver inductively coupled plasma mass spectrometer MC-ICP-MS detection.
1) The cleaned and cut samples were crushed and burned at 200-300 ℃ for 10 hours in double distilled HCl-HF-HNO3Is digested and then subjected to a second digestion in aqua regia.
2) The molybdenum isotope sample was purified by chelating resin Chelex-100. The purified sample was measured by a double-focusing multi-receiver Plasma mass spectrometer Nu Plasma HR manufactured by Nu Instruments. The DSN-100 type film was used to exsolve into the plasma.
3) Washing the sample with 0.5mol/L nitric acid for 5 min; then, the standard sample is washed by 0.05mol/L nitric acid for 3 min.
4) The MC-ICP-MS is used for measuring the isotope with high precision, the sample-standard sample intersection method is used for instrument quality discrimination correction, and the measured molybdenum isotope ratio result is expressed by the thousandth deviation of the sample relative to the standard sample.
S500, establishing delta through analysis of known molybdenum isotopes in different deposition environments, different maturity of source rocks, and crude oil and natural gas97Mo (mill) -oil reservoir type identification index chart. At the establishment of delta97Mo (‰) -reservoir type identificationWhen the index chart is used, the value range and the threshold value parameters of the molybdenum isotope ratios of oil reservoirs with different cause types need to be determined, and the molybdenum mass fractionation and non-mass fractionation information characteristics of the oil reservoirs with different cause types are summarized.
S600, determining the source and the cause of the unknown oil source according to the established identification index chart, and guiding exploration deployment.
After the method is used for establishing the identification index chart, the source and the cause of oil gas can be determined by carrying out molybdenum isotope analysis on the crude oil sample of the new well, and subsequent exploration deployment is guided.
Drawings
FIG. 1 shows δ established in accordance with an embodiment of the present invention97Mo (mill) -oil reservoir type identification index chart.
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 embodiment of the invention is specifically explained by taking a Bohai Bay basin oil reservoir as an example, and the specific method comprises the following steps:
s111, taking about 20g of a fresh crude oil sample from an oil outlet well head of a production well site; weighing 6-8 g of fresh crude oil in a quartz beaker, adding 15mL of petroleum ether, shaking up to mix the crude oil and the petroleum ether basically, adding 15mL of absolute ethyl alcohol, and heating for 12 hours at 80 ℃ on an electric hot plate after shaking up.
And S112, weighing 6-8 g of fresh crude oil in the quartz beaker again, and repeating the process of S110.
S113, standing the primary samples prepared twice for 24 hours at normal temperature, respectively extracting upper oil samples, mixing, adding 20mL of absolute ethyl alcohol, shaking up, and heating at 60 ℃ for 18 hours on an electric hot plate to prepare a crude oil sample to be tested.
S120, separation and purification of molybdenum element in the crude oil sample:
1) accurately weighing 1g of crude oil sample in a high-pressure closed digestion tank, and adding 2mL of CH2Cl2Fully dissolving the crude oil, and then5mL of concentrated HNO was added3-H2O2Digesting the reagent at the high temperature of 200 ℃ for 5min, cooling, then using high-purity water to fix the volume to 30mL, and placing the fixed-volume sample in a drying cabinet at the temperature of 600 ℃ for 24h to remove organic matters.
2) 2mL of 2mol/L HNO was added3And 4mL of 0.5mol/L HF, covering a cover, dissolving the sample, and putting the sample into an oven for reacting for 48 hours at 220 ℃; the steps can be repeated until the sample is completely dissolved, the sample is taken out after cooling, and the sample is dried on a heating plate at 200 ℃ until the sample is in a wet salt state; then 2mL of 2mol/L HNO is added3And (3) removing redundant HF, repeatedly removing the HF for 3 times, finally adding 5mL of 6mol/L HCl, and evaporating to dryness to obtain powder.
3) Purifying the Mo sample by using a Chelx100 resin and TSK-8HG resin double-column method, separating molybdenum element by using 7mol/L HCl as a medium, evaporating the purified molybdenum solution to dryness, and converting the molybdenum solution into 2% HNO3Medium to be tested. Conversion to 2% HNO3The medium is specifically as follows: adding 8mol/L HNO3About 20. mu.L of sample was converted to 2% HNO3A medium; conversion of the sample to 2% HNO3The medium is used to meet the acidic medium requirement of instrument test.
S210, preparing source rock sample powder:
1) selecting a rock sample: and (4) observing whether the surface of the rock sample is fresh or not and the weathering degree, and taking a photo to describe the information of the sample and inputting the information into a sample table. Wrapping the sample with clean cloth, covering the top and bottom surfaces of the sample with a wood board, hammering the wood board with a steel hammer to break the sample, selecting about 5g of sample particles with fresh four sides, no quartz vein and no wormhole structure after the sample is broken, clamping the sample with a disposable clamp, putting the sample into a sample bag, and recording and taking the number. 2) Sample crushing: selecting two identical grinding tanks, placing one of the grinding tanks into an agate ball, a) adding quartz sand into the grinding tank with the agate ball to cover the agate ball in half, screwing the two grinding tanks, placing the grinding tanks on a sample crusher, fixing the grinding tanks, rotating at 1300 rpm for 3 minutes, taking down the quartz powder after the rotation is finished, observing whether the inner surfaces of the grinding tanks are clean, and continuing the step if the inner surfaces of the grinding tanks are not clean. b) Clamping a sample in a sample bag by using a disposable pliers, putting the sample into a grinding tank, screwing the sample on a sample crusher, fixing the sample at a speed of 1300r/min, rotating the sample for 3 minutes, taking down the sample powder after the rotation is finished, pouring the sample powder onto disposable paper, wiping the inner surface of the grinding tank and an agate ball by using a disposable paper towel to pour the sample powder out as much as possible, and pouring the sample powder into the sample bag to record a serial number. c) Washing the grinding tank, and repeating the step a) for 2-3 times (for sure to ensure that the inner surface of the grinding tank is clean). Then the next sample crushing work is carried out in sequence.
S220, separation and purification of molybdenum in sample powder:
1) weighing about 1g of sample powder in a 20mL high-pressure digestion tank, adding 20mL of 3mol/L HCl by using a liquid transfer gun, covering a cover, fully reacting, standing for 24h, then washing by using deionized water, putting into a 3200r/min centrifugal machine for centrifugation for ten minutes after washing, washing for at least 4 times, and washing until the sample powder is no longer acidic.
2) Putting into a 75 ℃ oven for reaction for 12-20h, drying, grinding into powder by a weighing spoon, and weighing 6 mg.
3) Purifying Mo sample with chelating resin Chelex-100 to separate out molybdenum element, and preparing 2mol/L HNO3Completely dissolving the sample powder with 6mol/L HNO3Washing ion exchange resin with solution and deionized water, washing the same amount of molybdenum allelotide with mixed solution of 0.02mol/L HCl and 0.2mol/L HF, and then washing with 8mol/L NH3The solution is collected to molybdenum element in ion exchange resin, is evaporated to dryness in a drying oven at 150 ℃ and then 2mol/L HNO is used3Dissolving, finally dissolving the sample in 0.3mol/L HNO3Solution, to be tested.
S300, testing and analyzing the content of the molybdenum element:
1) and drying the sample in an oven at the temperature of more than 150 ℃ for 2 hours to remove the adsorbed water on the surface of the sample.
2) 5g of sample is accurately weighed, the sample is placed in a high-temperature furnace at 800 ℃ for ashing treatment, and 5mL of nitric acid is added into the treated residue. Placing on an electric heating plate, keeping the temperature at 250 ℃, and heating for dissolving. If turbidity occurs, adding proper amount of 0.5mol/L sulfuric acid to remove.
3) The Ca ions in the sample can be removed by adding a proper amount of 2mol/L ammonium chloride.
4) Adding 5mL of each of high-purity HCl and high-purity HF, covering and sealing a steel sleeve, and putting the mixture into an oven at 200 ℃ for constant temperature for 48 hours. After cooling, the mixture was evaporated to dryness on a hot plate, and 3mL of high purity HCl was added and evaporated to a wet salt state (to remove residual HF).
5) The total molybdenum content was then determined by performing a total digestion in diaminoethane tetraacetate and making the solution acidic. And (3) determining the content of the iron element by using the digested sample, and determining by using a multi-receiving inductively coupled plasma mass spectrometer MC-ICP-MS.
S400, detecting and analyzing the stable isotope composition of molybdenum:
(1) the cleaned and cut samples were crushed and burned at 200-300 ℃ for 10 hours in double distilled HCl-HF-HNO3Is digested and then subjected to a second digestion in aqua regia.
(2) The molybdenum isotope sample was purified by chelating resin Chelex-100. The purified sample was measured by a double-focusing multi-receiver Plasma mass spectrometer Nu Plasma HR manufactured by NuInstructions. The DSN-100 type film was used to exsolve into the plasma.
(3) Washing the sample with 0.5mol/L nitric acid for 5 min; then, the standard sample is washed by 0.05mol/L nitric acid for 3 min.
(4) The MC-ICP-MS is used for measuring the isotope with high precision, the sample-standard sample intersection method is used for instrument quality discrimination correction, and the measured molybdenum isotope ratio result is expressed by the thousandth deviation of the sample relative to the standard sample.
S500, establishing value ranges and boundary value parameters of molybdenum isotope ratios of oil reservoirs with different cause types through analyzing known molybdenum isotopes in different deposition environments, hydrocarbon source rocks with different maturity degrees and crude oil and natural gas, summarizing molybdenum mass fractionation and non-mass fractionation information characteristics of the oil reservoirs with different cause types, and establishing delta97Mo (mill) -oil reservoir type identification index chart.
Respectively collecting typical Bohai Bay basin samples, and detecting the composition and content of molybdenum isotopes in hydrocarbon source rocks and crude oil; according to the detection result, establishing value ranges and boundary value parameters of molybdenum isotope ratios of different cause types, summarizing molybdenum mass fractionation and non-mass fractionation information characteristics of different types of oil gas, establishing an identification index chart, and determining oil gas sources and causeAnd direct the exploration deployment. Wherein delta of molybdenum isotope in each oil reservoir sample of Bohai Bay basin97The results of the Mo (‰) data are shown in Table 1 below:
TABLE 1 Delta of molybdenum isotopes in oil reservoir samples of Bohai Bay basin97Data of Mo (‰)
Determining value ranges and boundary value parameters of molybdenum isotope ratios of oil reservoirs with different cause types according to data in table 1, summarizing molybdenum mass fractionation and non-mass fractionation information characteristics of the oil reservoirs with different causes, and measuring delta97The value of Mo is 1.32 per mill and 1.10 per mill of coal oil, 0.38 per mill and-0.42 per mill of land phase oil, and 0.52 per mill and 0.64 per mill of sea phase oil. A plurality of test analyses of a plurality of samples are carried out, and a judgment index chart is established as shown in figure 1.
At delta97Mo (‰) -oil deposit type identification index plate, delta of coal crude oil97Mo ranges from 1.04 to 1.58 per mill, delta of coal-series hydrocarbon source rock97Mo ranges from 0.78 to 1.41 per mill, delta of sea-phase crude oil97Mo ranges from 0.17 to 0.64 per mill, delta of marine hydrocarbon source rock97Mo ranges from 0.01 to 0.77 ‰, delta of continental-phase crude oil97Mo ranges from-0.46 to-0.14 per mill, delta of continental-phase hydrocarbon source rock97Mo (mill) ranges from-0.79 per mill to-0.08 per mill.
S600, judging the index chart according to the established figure 1, determining the source and the cause of the unknown oil source, and guiding exploration deployment.
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.
Claims (14)
1. A method for performing oil source comparison by using molybdenum isotopes is characterized by comprising the following steps:
s100, separating and enriching molybdenum elements in the crude oil;
s200, separating and enriching molybdenum elements in the source rocks;
s300, testing and analyzing the content of the molybdenum element;
s400, detecting and analyzing the stable isotope composition of molybdenum;
s500, establishing delta through analysis of molybdenum isotopes in known different deposition environments, different maturity hydrocarbon source rocks and crude oil and hydrocarbon source rocks with different properties97Mo,% o-reservoir type identification index chart;
s600, determining the source and cause of an unknown oil source according to the established identification index chart;
in S300, a multi-receiving inductively coupled plasma mass spectrometer MC-ICP-MS is used for measuring the content of the molybdenum element, and the method comprises the following steps:
1) drying the sample to remove the adsorbed water on the surface of the sample;
2) accurately weighing 5g of sample, and carrying out ashing treatment; adding 5mL of nitric acid into the treated residue, placing the residue on an electric hot plate, keeping the temperature at 250 ℃, and heating to dissolve the residue; if the turbid matter appears, adding a proper amount of 0.5mol/L sulfuric acid to remove;
3) adding 2mol/L ammonium chloride to remove Ca ions in the sample;
4) adding 5mL of each of high-purity HCl and high-purity HF, covering and sealing a steel sleeve, and putting the mixture into an oven at 200 ℃ for keeping the temperature for 48 hours; after cooling, evaporating to dryness on an electric hot plate, and then adding 3mL of high-purity HCl to evaporate to a wet salt state;
5) the total molybdenum content was then determined by total digestion in diaminoethane tetraacetate and by making the solution acidic; and (3) determining the content of the iron element by using the digested sample, and determining by using a multi-receiving inductively coupled plasma mass spectrometer MC-ICP-MS.
2. The method of claim 1, wherein δ97Delta of coal crude oil in Mo,% o-reservoir type identification index chart97Mo, range of 1.04-1.58 per mill, delta of coal-series hydrocarbon source rock97Mo, 0.78-1.41 per mill range, delta of sea phase crude oil97Mo, 0.17-0.64 per mill, delta of marine hydrocarbon source rock97Mo, 0.01-0.77 ‰, delta of continental-phase crude oil97Mo, the range of-0.46 to-0.14 per mill, delta of continental facies hydrocarbon source rock97Mo, the range of per mill is-0.79 per mill to-0.08 per mill.
3. The method of claim 1, wherein the source rock and crude oil are derived from an oil field cored or marginal outcrop rock sample, respectively, a petroleum sample from a normal production well.
4. The method according to claim 1, wherein S100 specifically comprises:
s110, preparing a crude oil sample;
s120, separating and purifying molybdenum element in the crude oil sample.
5. The method of claim 4, wherein the preparing of the S110 crude oil sample comprises:
s111, taking fresh crude oil, sequentially adding petroleum ether and ethanol for mixing and dissolving, and heating to obtain a primary sample;
s112, weighing fresh crude oil again, and repeating the process of S111;
s113, standing the primary samples prepared twice at normal temperature, respectively extracting upper oil samples, mixing, adding absolute ethyl alcohol, shaking up, and heating to prepare a crude oil sample to be tested.
6. The method of claim 5, wherein in S111, the ratio of crude oil, petroleum ether and ethanol is: 6-8 g: 14-16 mL: 14-16 mL.
7. The method according to claim 5, wherein the heating in S111 is performed at a temperature of 75 to 85 ℃ for 11 to 13 hours.
8. The method according to claim 5, wherein the S113 is left standing for 22 to 24 hours and heated at 60 to 70 ℃ for 16 to 18 hours.
9. The method as claimed in claim 4, wherein the separation and purification of molybdenum element in the S120 crude oil sample comprises:
1) digesting a crude oil sample;
2) dissolving the digested sample in HNO3And HF, heating for reaction until the sample is completely dissolved; evaporating to dryness to form wet salt after the reaction is finished, and then using HNO3Removing redundant HF, finally adding HCl, and evaporating to dryness to obtain powder;
3) purifying a Mo sample by using a Chelx100 resin and TSK-8HG resin double-column method, separating molybdenum element by using 7mol/LHCl as a medium, evaporating a molybdenum solution obtained by purification to dryness, and converting the molybdenum solution into 2% HNO3Medium to be tested.
10. The method according to claim 9, wherein the digestion solvent is dichloromethane and the digestion reagent is HNO3-H2O2And (4) digesting the system.
11. The method according to claim 1, wherein S200 specifically comprises:
s210, selecting and crushing a rock sample to obtain sample powder of the hydrocarbon source rock;
s220, separating and purifying molybdenum element in the sample powder.
12. The method of claim 11, wherein S210 comprises:
s211, selecting a rock sample;
and S212, crushing the sample, and grinding to obtain sample powder.
13. The method of claim 11, wherein the separation and purification of the molybdenum element in the S220 sample powder comprises:
1) adding HCl into the sample powder in a high-pressure digestion tank to perform digestion reaction; after the reaction is finished, centrifugally cleaning the mixture by using deionized water;
2) drying the centrifugally cleaned sample, and grinding into powder;
3) purifying the Mo sample by using Chelex-100 resin to separate out the molybdenum element;
firstly, 2mol/L of HNO is used3Completely dissolving the sample powder with 6mol/L HNO3The solution and deionized water are used for cleaning the resin, then the mixed solution of 0.02mol/L HCl and 0.2mol/L HF is used for washing the same amount of the isomorphin of the molybdenum, and 8mol/L NH is used3Collecting molybdenum element in ion exchange resin, purifying to obtain molybdenum solution, evaporating to dryness, dissolving with nitric acid, and dissolving in 0.3mol/L HNO3Solution, to be tested.
14. The method of claim 1, wherein stable isotope composition of molybdenum is analyzed in S400 using multi-receiver inductively coupled plasma mass spectrometer MC-ICP-MS detection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910608051.5A CN110412106B (en) | 2019-07-08 | 2019-07-08 | Method for performing oil source comparison by using molybdenum isotope |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910608051.5A CN110412106B (en) | 2019-07-08 | 2019-07-08 | Method for performing oil source comparison by using molybdenum isotope |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110412106A CN110412106A (en) | 2019-11-05 |
| CN110412106B true CN110412106B (en) | 2022-03-29 |
Family
ID=68360460
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910608051.5A Active CN110412106B (en) | 2019-07-08 | 2019-07-08 | Method for performing oil source comparison by using molybdenum isotope |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110412106B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106153871A (en) * | 2015-03-23 | 2016-11-23 | 中国石油化工股份有限公司 | A kind of OIL SOURCE CORRELATION method |
| CN109253994A (en) * | 2018-10-31 | 2019-01-22 | 中国石油天然气股份有限公司 | A kind of oil-gas-source mercury isotope detection method and device |
-
2019
- 2019-07-08 CN CN201910608051.5A patent/CN110412106B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106153871A (en) * | 2015-03-23 | 2016-11-23 | 中国石油化工股份有限公司 | A kind of OIL SOURCE CORRELATION method |
| CN109253994A (en) * | 2018-10-31 | 2019-01-22 | 中国石油天然气股份有限公司 | A kind of oil-gas-source mercury isotope detection method and device |
Non-Patent Citations (4)
| Title |
|---|
| Determination of the Isotopic Composition of Molybdenum in the Bottom Sediments of Freshwater Basins;D. N. Malinovskii等;《GEOCHEMISTRY INTERNATIONAL》;20070430;第45卷(第4期);全文 * |
| 含水原油中金属含量的测定;居美华;《杭州化工》;20040930;第34卷(第3期);第37页左栏第1段、最后1段，右栏第3段 * |
| 微波消解-ICP-MS法同时测定营养素补充剂中20种元素;曹璨等;《分析仪器》;20170528(第3期);第67-72页 * |
| 钼及钼同位素地球化学――同位素体系、测试技术及在地质中的应用;徐林刚等;《矿床地质》;20110215;第30卷(第01期);第110页右栏最后1段，第111页左栏第1段、右栏第1段 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110412106A (en) | 2019-11-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110412107B (en) | Method for developing oil source comparison by using uranium isotope | |
| CN110412112B (en) | Method for performing oil source comparison by using magnesium isotope | |
| CN102798644B (en) | Separating method and detection method for free carbon in vanadium carbide | |
| Huang et al. | High-precision determination of stable potassium and magnesium isotopes utilizing single column separation and multicollector inductively coupled plasma mass spectrometry | |
| CN110412110B (en) | Method for performing oil source comparison by using lithium isotope | |
| CN110426443B (en) | Method for performing oil source comparison by using copper isotope | |
| CN111443079A (en) | Method for simultaneously detecting contents of trace As, Pb, Cd, Zn, Cr, Co and V elements in ferric trichloride | |
| CN110412106B (en) | Method for performing oil source comparison by using molybdenum isotope | |
| CN110412111B (en) | Method for performing oil source comparison by using chromium isotope | |
| CN108593606B (en) | Method for testing germanium content in coal by utilizing atomic fluorescence spectroscopy | |
| CN110412113B (en) | Method for performing oil source comparison by using strontium isotope | |
| CN110412108B (en) | Method for performing oil source comparison by using iron isotope | |
| CN102661885A (en) | Method for enriching trace metallic elements in crude oil or deposited organic matters | |
| Shunxin et al. | Separation and preconcentration of Se (IV)/Se (VI) speciation on algae and determination by graphite furnace atomic absorption spectrometry in sediment and water | |
| KR101136557B1 (en) | measurement method for fluorine of soil | |
| CN110412109B (en) | Method for performing oil source comparison by using zinc isotope | |
| CN104655713A (en) | Method for measuring lithium isotope in fluid inclusion water | |
| CN112461945B (en) | Method for simultaneously and rapidly analyzing dibutyl phosphate, monobutyl phosphate, n-butyric acid, NO 3-and NO2- | |
| CN102830074A (en) | Quantitative analysis method of scandium in titanium slag chlorinated waste | |
| Law et al. | Solvent extraction in the presence of emulsion-forming residues. Application to the atomic absorption determination of gold in low-grade ores | |
| Salar Amoli et al. | Closed vessels microwave digestion method for uranium analysis of soils using alpha-spectroscopy | |
| CN111443078A (en) | Method for simultaneously detecting contents of trace As, Pb, Cd, Zn and Cr elements in ferrous chloride | |
| CN112710724B (en) | Method and device for quickly determining shale gas high-yield well group based on uranium isotope content | |
| CN112710725B (en) | Sandstone type uranium ore deep penetration geochemical ionization weak information extraction method | |
| CN115993391B (en) | Method for determining years and analyzing Mg isotopes of fourth-period rock salt sample U-Th |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |