CN117007627A - Analysis method for quantitatively representing shale organic pore porosity by nuclear magnetic resonance technology - Google Patents
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- 238000005481 NMR spectroscopy Methods 0.000 title claims abstract description 67
- 239000011148 porous material Substances 0.000 title claims abstract description 61
- 238000004458 analytical method Methods 0.000 title claims abstract description 22
- 238000005516 engineering process Methods 0.000 title claims abstract description 9
- 238000012360 testing method Methods 0.000 claims abstract description 42
- 229920006395 saturated elastomer Polymers 0.000 claims abstract description 37
- 238000001228 spectrum Methods 0.000 claims abstract description 33
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 31
- 238000000034 method Methods 0.000 claims abstract description 18
- 238000001035 drying Methods 0.000 claims abstract description 7
- 238000009738 saturating Methods 0.000 claims abstract description 5
- SNRUBQQJIBEYMU-UHFFFAOYSA-N dodecane Chemical compound CCCCCCCCCCCC SNRUBQQJIBEYMU-UHFFFAOYSA-N 0.000 claims description 10
- 238000000685 Carr-Purcell-Meiboom-Gill pulse sequence Methods 0.000 claims description 3
- 230000037452 priming Effects 0.000 claims description 3
- 238000012512 characterization method Methods 0.000 description 6
- 239000003153 chemical reaction reagent Substances 0.000 description 5
- 238000004364 calculation method Methods 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
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- 239000003245 coal Substances 0.000 description 2
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- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
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- 238000013459 approach Methods 0.000 description 1
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- 239000002734 clay mineral Substances 0.000 description 1
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- 238000005553 drilling Methods 0.000 description 1
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- 238000012764 semi-quantitative analysis Methods 0.000 description 1
- 238000009489 vacuum treatment Methods 0.000 description 1
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Abstract
The application discloses an analysis method for quantitatively characterizing shale organic pore porosity by utilizing nuclear magnetic resonance technology, which comprises the following steps: A. performing nuclear magnetic resonance test on the dried shale sample to obtain a base signal; B. c, performing nuclear magnetic resonance test after the dried shale sample is saturated with water, and subtracting the base signal obtained in the step A from the obtained signal to obtain the relaxation time T of the shale sample saturated with water 2 Spectrum, according to shale sample saturated water relaxation time T 2 Spectrum to obtain total porosity; C. c, drying the shale sample tested in the step B, and saturating the shale sample with light oil; D. placing the shale sample treated in the step C in MnCl 2 Self-priming of the solution to saturate MnCl 2 Solution, saturated MnCl 2 And C, performing nuclear magnetic resonance test after the solution, and subtracting the base signal obtained in the step A from the obtained signal to obtain shale sample saturated MnCl 2 Solution relaxation time T 2 Spectra, according to shale sample saturation MnCl 2 Solution relaxation time T 2 The spectrum gives the organic pore porosity. The application provides an analysisThe method can be used for qualitatively and quantitatively analyzing the organic pore content of the shale sample with lower cost.
Description
Technical Field
The application relates to the field of petroleum exploration and development, and particularly relates to a method for determining shale organic pore porosity based on a low-field nuclear magnetic resonance technology aiming at the microstructure characterization of an unconventional reservoir, which is used for finely describing shale pore structure characteristics.
Background
Shale gas is in free, adsorbed and small dissolved states that are present in the pores or cracks of shale and its interlayers. Unlike conventional gas reservoirs, the pores in shale gas reservoirs are distributed in nanoscale dimensions and the pore types have diverse characteristics (which can be classified into organic pores, inorganic pores and microcracks by the type of formation), which presents difficulties for reservoir pore structure characterization work and also makes conventional gas reservoir evaluation methods difficult to apply in this field.
Quantitative determination of the relative content of organic and inorganic pores is a major difficulty in the characterization of the micro-pore structure of shale reservoirs. This requires dividing the different types of pores and determining their relative amounts based on a qualitative assessment of the pore type. Aiming at the scientific problem, the existing method mainly utilizes technologies such as a focused ion beam scanning electron microscope (FIB-SEM) and nano CT scanning to carry out three-dimensional reconstruction on the basis of 2D image recognition statistics. The related instruments are difficult to popularize due to high use cost, which results in high test cost (usually 2-3 ten thousand yuan per sample).
In terms of calculation methods, the prior art is mainly based on the method of linear regression of petrophysical parameters and geochemical parameters to calculate the organic pores in shale. The scanning electron microscope 2D image is identified, and the organic hole and inorganic hole surface hole rate is calculated by a statistical method, so that the statistics of the organic holes under the microscopic scale is carried out, the methods are mainly based on semi-quantitative analysis, the result is limited to the microscopic scale, and the accuracy is greatly influenced by the sample size.
In summary, the quantitative characterization method for shale organic holes and inorganic holes in the prior art has the problems of high test cost, difficulty in qualitative and quantitative determination, limited application range and low accuracy.
Disclosure of Invention
According to the analysis method for quantitatively characterizing the porosity of the shale organic pores by utilizing the nuclear magnetic resonance technology, which aims at the problems in the prior art, the organic pore and inorganic pore contents of the shale can be determined under the low-field nuclear magnetic resonance condition by treating shale samples by different reagents, so that the testing cost is reduced, the applicability is wide, and the testing accuracy is improved.
The application provides an analysis method for quantitatively characterizing shale organic pore porosity by utilizing nuclear magnetic resonance technology, which comprises the following steps:
A. performing nuclear magnetic resonance test on the dried shale sample to obtain a base signal;
B. c, performing nuclear magnetic resonance test after the dried shale sample is saturated with water, and subtracting the base signal obtained in the step A from the obtained signal to obtain the relaxation time T of the shale sample saturated with water 2 Spectrum, according to shale sample saturated water relaxation time T 2 Spectrum to obtain total porosity;
C. c, drying the shale sample tested in the step B, and saturating the shale sample with light oil;
D. placing the shale sample treated in the step C in MnCl 2 Self-priming of the solution to saturate MnCl 2 Solution, saturated MnCl 2 And C, performing nuclear magnetic resonance test after the solution, and subtracting the base signal obtained in the step A from the obtained signal to obtain shale sample saturated MnCl 2 Solution relaxation time T 2 Spectra, according to shale sample saturation MnCl 2 Solution relaxation time T 2 The spectrum gives the organic pore porosity.
In the present application, the term "organic pores" refers to the pores distributed within the shale organic matter, and the term "inorganic pores" refers broadly to the pores distributed between and within the mineral particles. The total porosity of shale generally refers to the sum of organic and inorganic pore porosity.
Since shale samples may themselves carry nuclear magnetic resonance signals and noise signals derived from strongly bound water within the sample, fluids within closed cells, magnetic impurities, etc., prior to saturation with water. In the step A of the analysis method, the basal signal of the shale sample is tested, and the saturated water relaxation time T of the shale sample is obtained 2 Spectral and shale sample saturated MnCl 2 Solution relaxation time T 2 Subtracting the data of the base signal from the spectral time can avoid interference.
In the application, nuclear magnetic resonance data obtained by testing can be subjected to inversion calculation by using data processing software equipped with a nuclear magnetic resonance analyzer to obtain relaxation time T 2 A spectrum.
In the step B, saturated water is carried out on the shale sample, the organic holes and the inorganic holes are filled with water, the shale sample with the saturated water is put into a nuclear magnetic resonance apparatus, nuclear magnetic resonance signals can be calculated through inversion by using data processing software equipped by the nuclear magnetic resonance apparatus, and the saturated water relaxation time T of the shale sample is obtained 2 Spectrum, so that the total porosity of the shale sample can be calculated. In the present application, a method of calculating porosity by nuclear magnetic resonance general in industry can be adopted, for example, refer to Zla B, dla B, yca B, et al application of Nuclear Magnetic Resonance (NMR) in coalbed methane and shale reservoirs: A review [ J ]].International Journal of Coal Geology,2018. Nuclear magnetic resonance calculated porosity method disclosed.
The wettability of different matrixes in shale is different, the organic matters are generally oleophilic, and the mineral matrixes are hydrophilic, and the light oil is firstly used for saturation, so that all pores of a sample are filled with the light oil. Then put the saturated light oil sample into MnCl 2 Self-priming is carried out in the solution, at this time, the light oil in the inorganic holes is replaced by MnCl due to the oleophylic organic holes and the hydrophilic inorganic holes 2 The solution and the organic holes are still light oil. Mn (Mn) 2+ The nuclear magnetic resonance signal of the water phase is eliminated, at the moment, nuclear magnetic resonance test is carried out on the sample, only light oil in the organic pores generates nuclear magnetic resonance signals, and the porosity of the organic pores of the shale sample can be obtained by the same calculation method of saturated water experiments.
According to some embodiments of the application, step C further comprises performing a nuclear magnetic resonance test on the shale sample after saturation with light oil. According to the relaxation time T of shale sample saturated light oil 2 The spectrum confirms whether the sample is completely dry without moisture residue, if T 2 When the spectrum shows that moisture remains, the shale samples are not completely dried, and the follow-up test results are affected, so that the shale samples cannot be used continuously; if T 2 The spectrum shows no moisture residue and proceeds to the next step.
The nuclear magnetic resonance test result of the step C can also observe the degree of light oil entering the pores, and the degree is equal to the T of the previous and subsequent steps 2 The spectra are compared.
In the application, the standard for judging the shale sample saturation reagent is that the result of the multiple nuclear magnetic resonance test is relatively constant.
According to some embodiments of the application, the method further comprises subtracting the organic porosity from the total porosity to obtain an inorganic pore porosity of the shale sample.
According to some embodiments of the application, step C saturates the light oil by: and C, vacuumizing the dried shale sample tested in the step B, and placing the shale sample in light oil.
According to some embodiments of the applicationIn a mode, the light oil is C 5 -C 12 Preferably dodecane.
According to some embodiments of the application, the saturated light oil is carried out at a pressure of 8-12MPa, preferably 10 MPa.
According to some embodiments of the application, the shale sample is obtained by pre-treating a shale core or block sample, wherein the pre-treating preferably comprises cutting the shale core or block sample into shale sample columns with equal volumes in a direction perpendicular to a bedding surface, and calculating a total volume parameter of the sample.
According to some embodiments of the application, the shale samples are of any shape that can be placed into a low field nmr, but the size and shape of each sample should be as uniform as possible to reduce relative errors during testing.
According to some embodiments of the application, the top and bottom surfaces of the shale sample column are parallel to the bedding surface.
According to some embodiments of the application, the shale sample column has a length of 3-5cm.
According to some embodiments of the application, the shale sample column has a diameter of 2.5-2.6cm, for example 2.54cm.
According to some embodiments of the present application, the shale sample is baked in step a, resulting in a dried shale sample.
According to some embodiments of the application, the drying temperature is 110-130 ℃.
According to some embodiments of the application, the drying time is 22-26 hours.
According to some embodiments of the application, the dried shale sample is saturated with water in step B by: and (5) placing the dried shale sample in a KCl solution for saturation.
According to the application, the shale sample is saturated with water by adopting the KCl solution, and the KCl can effectively inhibit the water-sensitive reaction of clay minerals in the core saturated water process, so that the damage of the sample is avoided.
According to some embodiments of the application, the KCl solution is 2.5-3.5% by mass.
According to some embodiments of the application, the KCl solution is 3% by mass.
According to some embodiments of the application, step B further comprises: the shale sample is evacuated before it is saturated with water.
According to some embodiments of the application, the saturated water process of step B comprises subjecting the sample to a vacuum for about 1 hour, and then placing the sample in a 3% by mass KCl solution for saturation under high pressure for 48 hours. After taking out the sample, the filter paper wetted with the KCl solution wipes off the liquid attached to the surface of the sample, and then the sample is placed into a low-field nuclear magnetic resonance apparatus for testing.
According to some embodiments of the application, saturating the dried shale sample with water is performed at a pressure of 8-12MPa, preferably 10 MPa.
According to some embodiments of the present application, the shale sample after testing in step B is placed in an oven and dried at 110-130 ℃ for, for example, 24 hours to remove water from the sample. The dried sample is then subjected to a vacuum treatment using a vacuum pump for about 1 hour, and then the sample is placed in a light oil reagent for saturation under high pressure for 48 hours, for example. After taking out the sample, the filter paper wetted with light oil wipes off the liquid attached to the surface of the sample, and then the sample is put into a low-field nuclear magnetic resonance apparatus for testing.
According to some embodiments of the application, the vacuum is applied to a vacuum level of-0.06 to-0.04 MPa, preferably-0.05 MPa.
According to some embodiments of the application, the MnCl in step D 2 The mass fraction of the solution is 41-45%.
According to some embodiments of the application, the MnCl in step D 2 The mass fraction of the solution was 43%.
According to some embodiments of the application, the self priming is performed at a pressure of 8-12MPa, preferably 10 MPa.
According to some embodiments of the application, the test parameters of the nmr apparatus are set as follows: with CPMG sequences, tw=6000, ns=64, te=0.2, nech=1000.
Where TW is waiting time, NS is the number of overlapping times, TE is the echo interval, NECH is the number of echoes.
According to some embodiments of the application, the nmr used in the application is a low field nmr with a magnetic field strength of 0.3±0.03T.
The setting of relevant test parameters of the nuclear magnetic resonance instrument can be changed according to the instrument model, the use requirement and the sample condition of a user, and mainly provides a general low-field nuclear magnetic resonance parameter setting scheme.
The self-priming time of the step D in the application can be properly adjusted according to the actual condition of the sample.
According to some embodiments of the application, during the self-priming in step D, samples are taken every 1-2 days for nuclear magnetic resonance testing until a nuclear magnetic resonance T is measured 2 No further changes in the spectrum occur.
According to some embodiments of the application, the self priming time is 14-16 days.
Compared with the prior art, the application has the following beneficial effects:
(1) According to the analysis method provided by the application, the shale sample is subjected to saturation treatment by using different reagents, so that the pores of the shale sample can pass through nuclear magnetic resonance T 2 Characterization by spectral means, differentiation of organic and inorganic pores by differences in the Kong Runshi properties of organic and inorganic pores, by relaxation time T 2 And (3) analyzing and calculating a spectrum, so that the total porosity and the organic pore porosity of the sample can be obtained, and the contents of the organic pores and the inorganic pores of the shale sample can be obtained.
(2) The analysis method provided by the application has wide applicability to shale samples, can analyze different types of shale samples, is not limited to microcosmic angles, has high result accuracy and is less influenced by samples.
(3) The analysis method provided by the application only needs to test in a low-field nuclear magnetic resonance instrument (about 1000 yuan samples/time and containing sample preparation), the instrument price is relatively low, and the test analysis can be carried out on batched samples at the same time, so that the research cost is greatly reduced.
(4) The analysis method provided by the application can provide basis for developing shale pore heterogeneity characterization, shale pore evolution research, shale rock matrix physical property research and the like, and has wide application value in the oil and gas exploration and development fields such as shale gas resource evaluation, unconventional oil and gas exploration and the like.
Drawings
FIG. 1 is a schematic flow chart of an analysis method according to an embodiment of the application;
FIG. 2 shows a nuclear magnetic resonance T of shale sample 1 according to an embodiment of the present application 2 A spectrum;
FIG. 3 shows a nuclear magnetic resonance T of shale sample as sample 2 according to an embodiment of the present application 2 A spectrum;
FIG. 4 shows a nuclear magnetic resonance T of shale sample 3 according to an embodiment of the present application 2 A spectrum;
FIG. 5 shows a nuclear magnetic resonance T of shale sample 4 according to an embodiment of the present application 2 A spectrum;
FIG. 6 shows a nuclear magnetic resonance T of shale sample 5 according to an embodiment of the present application 2 A spectrum;
FIG. 7 shows a nuclear magnetic resonance T of shale sample 6 according to an embodiment of the present application 2 A spectrum.
Detailed Description
In order that the application may be more readily understood, the application will be described in detail below with reference to the following examples, which are given by way of illustration only and are not limiting of the scope of application of the application.
The nuclear magnetic resonance apparatus used in the application is purchased from the company of new mai, su, and is model MesoMR23/12-060H-I nuclear magnetic resonance apparatus;
the shale sample used in the application is 4-well Longmaxi shale in Chuan Dong region;
dodecane used in the present application was analytically pure and was purchased from guangdong Weng Jiang chemical reagent limited.
Example 1
Referring to fig. 1, the shale sample is quantitatively characterized by organic/inorganic pores, comprising the following steps:
(1) Selecting a drilling core, cutting the core into standard plunger samples with the diameter of 2.54cm and the length of 3cm in a direction perpendicular to a bedding surface by using a core cutter, and then calculating the total volume of the plunger samples to be 15.2cm 3 ；
(2) The shale sample obtained in (1) is dried at 120 ℃ for 24 hours to remove water and volatile impurities in the pores of the sample. Nuclear magnetic resonance testing was then performed (CPMG sequence, tw=6000, ns=64, te=0.2, nech=10000, magnetic field strength 0.3T was used for the nuclear magnetic resonance test parameter settings) to obtain nuclear magnetic basal signals of the samples.
(3) The sample after the test in (2) is vacuumized for 1 hour (the vacuum degree is-0.05 MPa) by using a vacuum pump, and then the sample is placed in KCl solution with the mass fraction of 3% for saturation for 48 hours under the condition of high pressure (the pressure is 10 MPa). After taking out the sample, the filter paper wetted with the KCl solution wipes off the liquid adhering to the surface of the sample, and then the sample is subjected to nuclear magnetic resonance test (test parameters are the same as (2)).
(4) The shale sample after the test of (3) is placed in an oven and placed at 110 ℃ for 24 hours to remove water in the sample. And then the dried sample is vacuumized for 1 hour (the vacuum degree is-0.05 MPa) by using a vacuum pump, and then the sample is placed in dodecane to be saturated for 48 hours under the condition of high pressure (the pressure is 10 MPa). After taking out the sample, the liquid attached to the surface of the sample was wiped off with a filter paper wetted with dodecane, and then the sample was subjected to nuclear magnetic resonance test (test parameters are the same as (2)).
(5) Placing the shale sample after the test in (4) in saturated MnCl 2 Self-priming experiments (pressure 10 MPa) were carried out in solution (mass fraction 43%) for 15 days. Taking out the sample every two days for nuclear magnetic resonance test, observing self-priming condition of the sample until the nuclear magnetic resonance T of 15 th day and the previous day 2 The spectra are basically the same, and the final analysis result is taken as shale MnCl 2 Nuclear magnetic resonance data of solution self-priming experiments.
(6) Reference is made to Zla B, dla B, yca B, et al application of Nuclear Magnetic Resonance (NMR) in coalbed methane and shale reservoirs:A review [ J ]].International Journal of Coal Geology,2018. The nuclear magnetic resonance calculated porosity method disclosed therein calculates porosity. Specifically, the shale sample obtained by the test in (2) is used for the saturated water relaxation time T 2 Calculating the spectrum and the total volume of the sample to obtain the total porosity of the shale sample; saturated MnCl of shale sample obtained by testing in (5) 2 Solution relaxation time T 2 Calculating the spectrum and the total volume of the sample to obtain the organic pore porosity of the shale sample; the organic porosity is subtracted from the total porosity of the sample to obtain the inorganic porosity of the sample. The organic and inorganic pore content of the shale sample can be calculated.
Qualitative and quantitative analysis is carried out on the organic holes/inorganic holes of the shale samples by using different shale samples through the analysis method, so as to respectively obtain nuclear magnetic resonance relaxation time T 2 The spectra are shown in FIGS. 2-7.
As can be seen from fig. 2-7, in the self-priming experiment, the nuclear magnetic resonance porosity (which can be determined by T 2 The peak area of the spectrum is characterized) decrease and then plateau, the results from the 15 and 30 day self-priming approaches, the final results representing the organic pore porosity of the shale sample.
Through T 2 The results of the spectrum calculation are shown in Table 1.
TABLE 1
As can be seen from the results in Table 1, the shale sample nuclear magnetic resonance basal signal is distributed between 0.34 and 0.57%, the nuclear magnetic resonance porosity is distributed between 2.54 and 5.62%, the organic pore porosity is distributed between 1.59 and 3.40%, the inorganic pore porosity is distributed between 0.89 and 2.22%, and the organic Kong Zhanbi 52.9.9 and 68.8%. The organic pore porosity calculated by the analysis method disclosed by the application is close to the theoretical organic pore porosity calculated by the actual organic matter and inorganic matter content of the sample, so that the analysis method provided by the application can be used for carrying out qualitative and quantitative analysis on the organic pores/inorganic pores of shale more accurately.
Comparative example
The same shale samples 1-6 are identified by using a scanning electron microscope 2D image, and the organic pore surface porosity is calculated by a statistical method, so that the organic pores under the microscopic scale are counted, and the porosity results are shown in Table 2.
TABLE 2
In summary, the analysis method for quantitatively characterizing the porosity of the shale organic pores by utilizing the nuclear magnetic resonance technology provided by the application can quantitatively analyze the organic pores and the inorganic pores in the shale, and only needs to use a low-field nuclear magnetic resonance spectrometer, so that the detection cost is low.
What has been described above is merely a preferred example of the present application. It should be noted that other equivalent modifications and improvements will occur to those skilled in the art, and are intended to be within the scope of the present application, as a matter of common general knowledge in the art, in light of the technical teaching provided by the present application.
Claims (10)
1. An analytical method for quantitatively characterizing shale organic pore porosity by utilizing nuclear magnetic resonance technology, which is characterized by comprising the following steps:
A. performing nuclear magnetic resonance test on the dried shale sample to obtain a base signal;
B. c, performing nuclear magnetic resonance test after the dried shale sample is saturated with water, and subtracting the base signal obtained in the step A from the obtained signal to obtain the relaxation time T of the shale sample saturated with water 2 Spectrum, according to shale sample saturated water relaxation time T 2 Spectrum to obtain total porosity;
C. c, drying the shale sample tested in the step B, and saturating the shale sample with light oil;
D. placing the shale sample treated in the step C in MnCl 2 Self-priming of the solution to saturate MnCl 2 Solution, saturated MnCl 2 And C, performing nuclear magnetic resonance test after the solution, and subtracting the base signal obtained in the step A from the obtained signal to obtain shale sample saturated MnCl 2 Solution relaxation time T 2 Spectra, according to shale sample saturation MnCl 2 Solution relaxation time T 2 The spectrum gives the organic pore porosity.
2. The method of analysis of claim 1, further comprising subtracting the organic pore porosity from the total porosity to yield an inorganic pore porosity of the shale sample.
3. The analytical method according to claim 1 or 2, characterized in that step C is performed by saturating the light oil by: b, vacuumizing the dried shale sample tested in the step B, and placing the shale sample in light oil;
and/or the light oil is C 5 -C 14 Preferably dodecane;
and/or the saturated light oil is carried out at a pressure of 8-12MPa, preferably 10 MPa.
4. An analysis method according to any one of claims 1 to 3, wherein the shale sample is obtained from a shale core or block sample after a pretreatment process, the pretreatment process preferably comprising cutting the shale core or block sample into shale sample cylinders of equal volume in a direction perpendicular to the bedding plane, calculating the total volume parameter of the sample.
5. The method of analysis of claim 4, wherein the top and bottom surfaces of the shale sample column are parallel to the bedding surface;
preferably, the shale sample column has a length of 3-5cm;
preferably, the shale sample column has a diameter of 2.5-2.6cm, for example 2.54cm.
6. The method according to any one of claims 1 to 5, wherein in step a, the shale sample is dried to obtain a dried shale sample;
preferably, the temperature of the drying treatment is 110-130 ℃;
preferably, the drying treatment is carried out for a period of 22 to 26 hours.
7. The method of any one of claims 1-6, wherein the dried shale sample is saturated with water in step B by: placing the dried shale sample in KCl solution for saturation;
preferably, the KCl solution has a mass fraction of 2.5-3.5%;
and/or, the dried shale sample is saturated with water at a pressure of 8-12MPa, preferably 10 MPa.
8. The method according to any one of claims 1 to 7, wherein in step D the MnCl 2 The mass fraction of the solution is 41-45%, preferably 43%;
and/or the self-priming is carried out at a pressure of 8-12MPa, preferably 10 MPa.
9. The method of any one of claims 1-8, wherein the test parameters of the nmr instrument are set to: with CPMG sequences, tw=6000, ns=64, te=0.2, nech=1000.
10. The method according to any one of claims 1 to 9, wherein MnCl is added every 1 to 2 days during self-priming in step D 2 Shale samples in solution are taken out for nuclear magnetic resonance testing until nuclear magnetic resonance T is detected 2 The spectrum is not changed any more, and saturated MnCl is obtained 2 Shale samples of the solution;
preferably, the self priming time is 14-16 days.
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| CN117269223A (en) * | 2023-11-20 | 2023-12-22 | 东北石油大学三亚海洋油气研究院 | Method for calibrating multi-scale crack two-dimensional nuclear magnetism T1-T2 distribution of lamellar shale |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117269223A (en) * | 2023-11-20 | 2023-12-22 | 东北石油大学三亚海洋油气研究院 | Method for calibrating multi-scale crack two-dimensional nuclear magnetism T1-T2 distribution of lamellar shale |
| CN117269223B (en) * | 2023-11-20 | 2024-01-26 | 东北石油大学三亚海洋油气研究院 | Method for calibrating multi-scale crack two-dimensional nuclear magnetism T1-T2 distribution of lamellar shale |
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