A method for identifying multiple-stage adjustment and reconstruction of reservoirs based on fluid inclusion multi-parameters

Abstract

The application provides a method for identifying multiple adjustment and reconstruction phases of an oil reservoir based on fluid inclusion multi-parameters, and relates to the technical field of oil and gas geological exploration, and specifically comprises the following steps: preparing a fluid inclusion slice; measuring the homogenization temperature of a brine inclusion synchronous with the oil inclusion; performing pre-treatment on the oil inclusion and preparing a drilling core sample; crushing, extracting, separating and purifying the oil inclusion to obtain oil inclusion extract liquid to be concentrated; concentrating the oil inclusion extract liquid to be concentrated and analyzing the concentrated oil inclusion extract liquid by using a gas chromatograph-mass spectrometer; and calibrating the charging phase and establishing a time sequence of crude oil charging and adjustment and reconstruction. The technical scheme of the application overcomes the problem in the prior art that complete records of oil and gas charging and adjustment and reconstruction cannot be extracted from the molecular geochemical characteristics of fluid inclusions, indirect tracing of early lost crude oil cannot be achieved, and the charging time and adjustment and reconstruction process cannot be accurately determined.

Description

Technical Field

[0001] This invention relates to the field of oil and gas geological exploration technology, specifically to a method for multi-stage adjustment and transformation of oil reservoirs based on multi-parameter identification of fluid inclusions. Background Technology

[0002] In recent years, fluid inclusion geochemistry has made significant progress in characterizing hydrocarbon charging history. Chinese patent CN202511493969 discloses a method for analyzing the composition of single-phase oil inclusions based on crude oil inclusions. This method achieves precise screening of single-phase samples through fluorescence microscopy and quantitative fluorescence analysis, establishes a differentiated cleaning and hydrocarbon removal process for calcite and quartz, and utilizes a zirconia crushing device to achieve parallel processing of multiple samples. This significantly improves the efficiency and reliability of extracting the components of single-phase oil inclusion groups, providing effective technical support for the geochemical characterization of single-phase hydrocarbon charging.

[0003] However, the above methods are only applicable to single-period samples that can be pre-screened, and cannot identify the source of crude oil in the reservoir. At the same time, they do not involve the homogenization temperature measurement of brine inclusions captured at the same time as oil inclusions and the simulation of basin burial history, nor do they apply the molecular geochemical characteristics of fluid inclusions to identify reservoir adjustment and modification processes.

[0004] Therefore, there is a need for a multi-parameter method based on fluid inclusions to identify multiple phases of reservoir adjustment and modification, which can extract a complete record of oil and gas charging and modification from a microscale system by integrating multiple parameters such as fluid inclusions, fluorescence spectroscopy, homogenization temperature, burial history and thermal history, and oil inclusion geochemical analysis. This method would enable indirect tracing of early lost crude oil and precise determination of charging time and adjustment and modification processes. Summary of the Invention

[0005] The main objective of this invention is to provide a method for multi-stage adjustment and modification of oil reservoirs based on multi-parameter identification of fluid inclusions, in order to solve the problems in the prior art that it is impossible to extract a complete record of oil and gas charging and adjustment and modification from the molecular geochemical characteristics of fluid inclusions, and that it is impossible to achieve indirect tracing of early lost crude oil and accurate determination of charging time and adjustment and modification process.

[0006] To achieve the above objectives, this invention provides a method for multi-stage adjustment and stimulation of reservoirs based on multi-parameter identification of fluid inclusions, specifically including the following steps: S1, collect core samples from the target formation and prepare fluid inclusion thin sections.

[0007] S2, Fluorescence microscopy was used to observe the fluid inclusions in thin sections, quantitative fluorescence analysis was performed on the selected oil inclusions, and the homogenization temperature of the brine inclusions was determined.

[0008] S3, pretreatment of oil inclusions for extraction and preparation of core samples.

[0009] S4. The oil inclusions are broken down, extracted, separated, and purified to obtain the concentrated oil inclusion extract.

[0010] S5. The oil inclusion extract to be concentrated was concentrated and analyzed using gas chromatography-mass spectrometry.

[0011] S6, calibrate the charging period and establish a time series of crude oil charging and adjustment.

[0012] Furthermore, the specific process of step S1 is as follows: Collect core samples from different strata and structural locations in complex structural areas, and cut and grind the selected core samples on both sides to form fluid inclusion thin sheets.

[0013] Furthermore, the specific process of step S2 is as follows: S2.1, Fluorescence microscopy was performed on the prepared fluid inclusion thin sections. Ultraviolet or blue light was used as the excitation source to identify the occurrence, distribution and fluorescence spectral characteristics of oil inclusions in different phases.

[0014] S2.2, Select oil inclusions for quantitative fluorescence analysis, obtain the maximum main peak wavelength λmax, and establish a fluorescence spectrum database of oil inclusions from different phases.

[0015] S2.3 Identify gas-liquid two-phase brine inclusions that were captured concurrently with oil inclusions, based on occurrence relationships, host mineral growth sequences, and phase characteristics.

[0016] S2.4. Homogenization temperature was measured using a geological hot and cold stage to record the temperature at which the gas-liquid two-phase brine inclusions were homogenized into the liquid phase.

[0017] S2.5, through statistical analysis, the homogeneous temperature main peak range of brine inclusions in each period is obtained, and the crude oil charging period of different layers is divided by combining fluorescence spectral characteristics.

[0018] Furthermore, the specific process of step S3 is as follows: Based on the results of fluorescence microscopy and quantitative fluorescence analysis in S2, the host mineral type, particle size distribution and abundance of oil inclusions in each phase were identified, the grinding mesh of the core samples was determined, 20-30g of core samples with only single-phase oil injection were weighed, and the samples were ground to the predetermined mesh size using a pollution-free agate mortar under normal temperature conditions to obtain rock particle samples.

[0019] Furthermore, the specific process of step S4 is as follows: S4.1 Place the rock particle sample obtained in S3 in a clean beaker and wash it with 10%~15% hydrogen peroxide, 5%~10% dilute hydrochloric acid and aqua regia in sequence. Then, use dichloromethane and methanol for ultrasonic cleaning to remove free hydrocarbons and contaminants attached to the surface of the rock particles.

[0020] S4.2, Collect the final washing solution and perform component analysis using gas chromatography-mass spectrometry to ensure that there are no hydrocarbon residues on the surface of the rock particles. Then, transfer the washed rock particle sample to the crushing device, add chromatographically pure solvent, ensuring that the solvent level is above the particles, and crush the particles using a multi-stage crushing process, each stage lasting 5 to 10 minutes.

[0021] S4.3, transfer all the fine rock particles and solution in the crushing device to a clean beaker for ultrasonic-assisted extraction to fully dissolve the hydrocarbons remaining on the surface of the rock particles.

[0022] S4.4 After standing, take the solvent of the upper layer containing oil inclusions extract, remove the suspended rock debris, and collect the filtrate in a clean round-bottom flask to obtain the oil inclusion extract to be concentrated.

[0023] Furthermore, the specific process of step S5 is as follows: S5.1, The oil inclusion extract obtained in step S4 is placed in a rotary evaporator for preliminary concentration. The vacuum degree is adjusted to above -0.06MPa to allow the solvent to evaporate slowly, and the preliminarily concentrated oil inclusion extract is obtained.

[0024] S5.2, the pre-concentrated oil inclusion extract is transferred to a sample vial and purged with high-purity nitrogen at 30°C to further concentrate the pre-concentrated oil inclusion extract. The final volume is adjusted to 0.3~0.7mL to obtain a concentrated oil inclusion extract suitable for instrumental analysis.

[0025] S5.3. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the concentrated extract of oil inclusions. The chromatographic column was an HP-5MS capillary column or a DB-5MS capillary column, and the carrier gas was high-purity helium. The hydrocarbon components were separated by temperature program. The mass spectrometry used an electron impact ion source and acquired data in full scan or selected ion monitoring mode.

[0026] S5.4, qualitative and quantitative analysis of geochemical parameters, including: n-alkanes, isoprene-like alkanes, steranes, terpenes and aromatics in oil inclusions.

[0027] Furthermore, the specific process of step S6 is as follows: S6.1 Project the homogenization temperature data of brine inclusions of each period onto the burial history and thermal history evolution map of the corresponding strata, and read the corresponding geological age on the burial history map.

[0028] S6.2, by comparing the geochemical characteristics of oil extracts, the source of oil and gas is identified, and the time of oil and gas charging is determined by combining fluid inclusions with burial history. Finally, the time series of crude oil charging and adjustment is determined.

[0029] This invention offers the following advantages: It utilizes the original hydrocarbon information preserved within fluid inclusions—a closed geological system—as a research carrier. By integrating multiple parameters such as fluorescence spectroscopy, homogenization temperature, basin simulation, and oil inclusion geochemical analysis, it systematically extracts complete records of crude oil charging and adjustment at the microscopic scale, thereby accurately identifying the source and origin of crude oil in each phase. This overcomes the bottleneck of traditional oil source correlation methods in areas with multiple phases of intense tectonic alteration. For the first time, fluid inclusion geochemistry is applied to the precise determination of the genesis of crude oil charging in each phase, achieving indirect tracing of crude oil lost after early charging. This overcomes the limitation of traditional oil source correlation relying solely on the geochemical information of mixed crude oil in the current reservoir, thus establishing the source identification and genetic connection of crude oil in each phase. Combining multi-phase charging information recorded by fluid inclusions with basin simulation effectively identifies adjustment and alteration events after the formation of hydrocarbon reservoirs, filling the gap in traditional methods for tracing early lost hydrocarbon information and providing a new technical path for the study of multi-phase hydrocarbon accumulation and adjustment in complex tectonic areas. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 The flowchart of a multi-stage adjustment and stimulation method for reservoirs based on multi-parameter identification of fluid inclusions according to the present invention is shown.

[0031] Figure 2 The petrographic features of blue fluorescent oil inclusions in the K1bs group of well (A) KL2-J204, 3921.06m, are shown.

[0032] Figure 3 The petrographic features of blue fluorescent oil inclusions in the K1y group of well (B) of this invention, at 5159.57m, are shown.

[0033] Figure 4 The frequency distribution histogram of fluorescence spectra of oil inclusions in the K1bs group of a gas field according to the present invention is shown.

[0034] Figure 5The frequency distribution histogram of fluorescence spectra of oil inclusions in the K1y group of a gas field according to the present invention is shown.

[0035] Figure 6 The histogram of homogenization temperature frequency distribution of gas-liquid two-phase brine inclusions contemporaneous with blue fluorescent oil inclusions in a gas field K1bs group of the present invention is shown.

[0036] Figure 7 The histogram of homogenization temperature frequency distribution of gas-liquid two-phase brine inclusions contemporaneous with blue fluorescent oil inclusions in a gas field K1y group of the present invention is shown.

[0037] Figure 8 The present invention illustrates the chromatographic and mass spectrometric spectra of saturated hydrocarbons containing blue fluorescent oil inclusions in the K1bs group of a gas field.

[0038] Figure 9 The present invention illustrates the chromatographic and mass spectra of saturated hydrocarbons containing blue fluorescent oil inclusions in the K1y group of a gas field.

[0039] Figure 10 The present invention Ph / nC is shown. 18 With Pr / nC 17 Intersection diagram.

[0040] Figure 11 The present invention illustrates Pr / Ph and C 27 / C 29 ααα20R intersection diagram.

[0041] Figure 12 The present invention C is shown. 19 TT / C 23 TT and C 24 Tet / C 26 TT intersection diagram.

[0042] Figure 13 The present invention illustrates gamma-ceramide / C 30 hopane and C 27 / C 29 ααα20R intersection diagram.

[0043] Figure 14 This invention demonstrates how the crude oil charging time of the K1bs and K1y reservoirs in a gas field can be determined by combining burial history. Detailed Implementation

[0044] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] like Figure 1 The method for multi-stage adjustment and stimulation of reservoirs based on multi-parameter identification of fluid inclusions, as shown, specifically includes the following steps: S1, collect core samples from the target formation and prepare fluid inclusion thin sections.

[0046] S2, Fluorescence microscopy was used to observe the fluid inclusions in thin sections, quantitative fluorescence analysis was performed on the selected oil inclusions, and the homogenization temperature of the brine inclusions was determined.

[0047] S3, pretreatment of oil inclusions for extraction and preparation of core samples.

[0048] S4. The oil inclusions are broken down, extracted, separated, and purified to obtain the concentrated oil inclusion extract.

[0049] S5. The oil inclusion extract to be concentrated was concentrated and analyzed using gas chromatography-mass spectrometry.

[0050] S6, calibrate the charging period and establish a time series of crude oil charging and adjustment.

[0051] Specifically, the process of step S1 is as follows: Core samples were collected from different strata and structural locations within complex geological zones. Based on detailed core descriptions, priority was given to selecting strata with clear oil-bearing displays and well-developed cementation. The samples were ensured to represent the geological record of each phase of oil and gas injection. The selected core samples were cut and ground on both sides into thin sections of fluid inclusions of a certain thickness for subsequent fluorescence microscopy and thermometry.

[0052] Specifically, the process of step S2 is as follows: S2.1 Fluorescence microscopy observation of the prepared fluid inclusion thin sections under a combined polarizing and fluorescence microscope, using ultraviolet or blue light excitation source, to identify the occurrence, distribution and fluorescence spectral characteristics of oil inclusions in different phases.

[0053] S2.2, Select oil inclusions for quantitative fluorescence analysis, obtain the maximum main peak wavelength λmax, and establish a fluorescence spectrum database of oil inclusions from different phases.

[0054] S2.3 Identify gas-liquid two-phase brine inclusions that were captured concurrently with oil inclusions, based on occurrence relationships, host mineral growth sequences, and phase characteristics.

[0055] S2.4. Homogenization temperature was measured using a geological hot and cold stage. A segmented heating program was used during the test. When approaching the phase transition point, the heating rate was reduced to 0.1~0.5 °C / min. The temperature at which the gas and liquid phases homogenized into the liquid phase was recorded. No less than 30 valid test data were collected for each period. The geological hot and cold stages included the Linkam THMSG 600 hot and cold stage and similar stages.

[0056] S2.5, through statistical analysis, the homogeneous temperature main peak range of brine inclusions in each period is obtained, and the crude oil charging period of different layers is divided by combining fluorescence spectral characteristics.

[0057] Specifically, the process of step S3 is as follows: Based on the results of fluorescence microscopy and quantitative fluorescence analysis in S2, the host mineral type, particle size distribution and abundance of oil inclusions in each phase were identified. Based on this, the grinding mesh number of the sample was determined to ensure that the grinding mesh number was less than the maximum diameter of the observed oil inclusions. 20-30 g of core samples from wells with only a single phase of oil filling were weighed and ground to the predetermined mesh number using a pollution-free agate mortar and pestle at room temperature. This ensured that the oil inclusions were fully exposed on the surface of the rock particles, while avoiding excessive grinding that could lead to the rupture of the inclusions and loss of the contents through volatilization, thus obtaining a rock particle sample.

[0058] Specifically, the process of step S4 is as follows: S4.1 Place the rock sample obtained in S3 in a clean beaker and wash it sequentially with 10%~15% hydrogen peroxide, 5%~10% dilute hydrochloric acid and aqua regia to remove carbonate minerals, sulfides and iron and manganese oxides. Then use dichloromethane and methanol for ultrasonic cleaning to remove free hydrocarbons and contaminants attached to the surface of rock particles and avoid interfering with the original components of the oil inclusions.

[0059] S4.2, Collect the final washing solution and perform component analysis using gas chromatography-mass spectrometry to ensure that there are no hydrocarbon residues on the surface of the rock particles. After ensuring that there are no hydrocarbon residues on the surface of the rock particles, transfer the washed sample to a ball mill equipped with zirconia crushing balls or a similar crushing device. Add chromatographically pure solvent, ensuring that the solvent level is above the particles. Use a multi-stage crushing process for 5-10 minutes each time. During the crushing process, the solvent continuously soaks the rock particles to fully dissolve the hydrocarbon components released after the oil inclusions rupture.

[0060] S4.3, transfer all the fine rock particles and solution in the crushing device to a clean beaker for ultrasonic-assisted extraction to fully dissolve the hydrocarbons remaining on the surface of the rock particles.

[0061] S4.4 After standing, take the solvent of the upper layer containing oil inclusions extract, remove the suspended rock debris, and collect the filtrate in a clean round-bottom flask to obtain the oil inclusion extract to be concentrated.

[0062] Specifically, the process of step S5 is as follows: S5.1, The oil inclusion extract obtained in step S4 is placed in a rotary evaporator for preliminary concentration. The vacuum degree is adjusted to above -0.06MPa to allow the solvent to evaporate slowly, avoiding the loss of target hydrocarbon components with solvent azeotropy, and the oil inclusion extract is obtained after preliminary concentration.

[0063] S5.2, the pre-concentrated oil inclusion extract is transferred to a sample vial and purged with high-purity nitrogen at 30°C to further concentrate the pre-concentrated oil inclusion extract. The final volume is adjusted to 0.3~0.7mL to obtain a concentrated oil inclusion extract suitable for instrumental analysis.

[0064] S5.3. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the concentrated extract of oil inclusions. The chromatographic column was an HP-5MS capillary column or a DB-5MS capillary column, and the carrier gas was high-purity helium. The hydrocarbon components were separated by temperature program. The mass spectrometry used an electron impact ion source and acquired data in full scan or selected ion monitoring mode.

[0065] S5.4, through comparison with standard spectral libraries and identification of characteristic ions of biomarker compounds, qualitative and quantitative analysis of geochemical parameters is performed. Geochemical parameters include: n-alkanes, isoprene-like alkanes, steranes, terpenes and aromatics in oil inclusions. Biomarker compound characteristic ions include: m / z 217, m / z 191 and m / z 178, thereby accurately determining the chemical composition and geochemical characteristics of oil inclusions in each phase.

[0066] Specifically, the process of step S6 is as follows: S6.1 Based on the completion of fluorescence spectroscopy analysis of oil inclusions and homogenization temperature determination of brine inclusions in the same period, the homogenization temperature data of brine inclusions in each period are projected onto the burial history and thermal history evolution map of the corresponding strata, and the corresponding geological age is read on the burial history map, so as to accurately determine the charging time of crude oil in each period.

[0067] S6.2, by comparing the geochemical characteristics of oil extracts, the source of oil and gas is identified, and the time of oil and gas charging is determined by combining fluid inclusions with burial history. Finally, the time series of crude oil charging and adjustment is determined.

[0068] To verify the method proposed in this invention, a verification experiment was conducted using two gas reservoirs in the Cretaceous Bashkichik Formation and Yagelem Formation of a gas field as examples: Based on detailed core descriptions and oil-bearing show observations, 33 core samples were selected from the Cretaceous Yageliemu Formation (K1y) and Bashkichik Formation (K1bs) reservoirs in wells KT1 and KL2-J204 of a gas field, with sampling depths ranging from 3900 to 6100 m. The Yageliemu Formation gas reservoir lies beneath the Bashkichik Formation gas reservoir, and the two reservoirs exhibit similar fluid properties. Priority was given to selecting sections with well-developed calcite veins and quartz secondary enlarged margins, and high oil inclusion abundance, to ensure that the samples could preserve geological information on different stages of oil and gas charging and adjustment. The selected core samples were ground into double-sided polished fluid inclusion thin sections with a thickness of approximately 0.05 mm, ensuring uniform thickness, a smooth and clean surface, and good transparency. This ensured clear identification of the occurrence and phase of fluid inclusions during subsequent fluorescence microscopy observation and met the experimental requirements for homogenization temperature determination.

[0069] Fluorescence microscopy was used to observe the prepared fluid inclusion sections under a combined polarized and fluorescence microscope. Ultraviolet light was used as the excitation source to identify the occurrence, distribution characteristics, fluorescence color, and intensity differences of oil inclusions from different stages. Figure 2 As shown, A2 is a magnified view of a point in A1, and A3 is a distribution map of oil inclusions in A2 under ultraviolet excitation. It can be seen that the K1y reservoir of a certain gas field only has abundant blue fluorescent oil inclusions, mainly distributed in secondary assemblages within healed microfractures of quartz grains. Figure 3 As shown, B2 is a magnified detail of a point in B1, and B3 is a distribution map of oil inclusions in B2 under ultraviolet excitation. It can be seen that the K1bs reservoir of a certain gas field only has abundant blue fluorescent oil inclusions, mainly distributed in secondary assemblages within healed microfractures of quartz grains. Figure 4 As shown, the maximum fluorescence wavelength λmax of oil inclusions in the K1y group reservoir of well KT1 is concentrated in the range of 450~460 nm. Figure 5 As shown, the maximum fluorescence wavelength λmax of the reservoir oil inclusions in the K1bs group of well KL2-J204 is concentrated in the range of 440~450 nm. Figure 4 and Figure 5 It can be seen that the captured crude oils have similar thermal maturity. Based on this, according to the occurrence relationship, host mineral growth sequence, and phase characteristics, brine inclusions captured at the same time as the oil inclusions were identified, and homogenization temperatures were measured using a Linkam THMSG 600 hot and cold stage. A segmented heating program was used during the test: the heating rate was 10 °C / min below 60 °C, and decreased to 2 °C / min above 60 °C. The heating rate was further reduced near the phase transition point, and the temperature at which the gas and liquid phases homogenized into the liquid phase was recorded. At least 30 valid test data points were collected for each period. Statistical analysis was used to obtain the main peak range of homogenization temperatures for brine inclusions in each period. The statistical results are shown below. Figure 6 and Figure 7 As shown: In the K1bs reservoir, the homogenization temperature peak of the gas-liquid two-phase brine inclusions contemporaneous with the blue fluorescent oil inclusions is between 90 and 100 °C (31 valid data points), while in the K1y reservoir, the homogenization temperature peak of the gas-liquid two-phase brine inclusions contemporaneous with the blue fluorescent oil inclusions is between 100 and 110 °C (43 valid data points).

[0070] Based on the results of fluorescence microscopy and quantitative fluorescence analysis, core samples from well KL2-J204 at 3921.06m and well KT1 at 5159.57m were selected, with approximately 20g of each sample weighed. Both samples contained only single-phase blue fluorescent oil inclusions. Subsequently, the samples were crushed into fragments of 0.5~0.25 mm (approximately 35~60 mesh) using an agate mortar and pestle to fully expose the host rock particles of the oil inclusions, while avoiding excessive crushing that could lead to premature rupture of the inclusions or loss of contents due to volatilization.

[0071] The obtained fragmented samples underwent thorough cleaning to remove free hydrocarbons and contaminants adhering to the particle surface, avoiding interference with the original components of the oil inclusions. First, the samples were ultrasonically cleaned with 10%–15% hydrogen peroxide for 10–15 min to remove organic matter between rock particles. Then, they were ultrasonically cleaned with 5% dilute hydrochloric acid for 10–15 min to dissolve and remove carbonate minerals. Next, the samples were reacted in boiling aqua regia for 5–10 min to thoroughly remove sulfides and iron / manganese oxides. The samples were repeatedly rinsed with distilled water until neutral, and then dried. Finally, the samples were ultrasonically cleaned sequentially with methanol, a mixture of dichloromethane and methanol (93:7 volume ratio), and pure dichloromethane, 2–3 times for each reagent, 10–15 min each time, to ensure complete removal of residual hydrocarbons from the rock particle surface. The final cleaning solution was used as the test sample and analyzed using gas chromatography-mass spectrometry (GC-MS) to detect the presence of residual hydrocarbons. If no hydrocarbons were detected, it indicated that the hydrocarbons were completely removed, meeting the fragmentation requirements.

[0072] The cleaned samples were transferred to a crushing apparatus equipped with zirconia crushing balls. 40 mL of dichloromethane (analytical grade, redistilled) was added, and a multi-stage crushing process was employed: the instrument parameters were set to 5 min for each crushing cycle, a total of 3 crushing cycles, and a 10 min interval between adjacent crushing cycles to minimize the evaporation loss of oil in the fluid inclusions. During the crushing process, the solvent continuously soaked the rock particles, ensuring the complete dissolution of hydrocarbon components released after the oil inclusions ruptured. Subsequently, all the finely crushed rock particles and solution in the crushing apparatus were transferred to a clean beaker for ultrasonic-assisted extraction, allowing the hydrocarbons remaining on the surface of the rock particles to dissolve completely. 40 mL of dichloromethane was added to the crushing vessel for soaking for 2 hours. The resulting soaking solution was transferred to the same beaker, and this soaking operation was repeated twice. After standing, the solvent containing the oil inclusion extract in the upper layer of the beaker was collected, filtered through a microporous membrane to remove suspended rock fragments, and the filtrate was collected in a clean round-bottom flask to obtain the oil inclusion extract to be concentrated.

[0073] The oil inclusion extract to be concentrated was initially concentrated in a rotary evaporator, with the water bath temperature controlled not to exceed 40 °C and the vacuum adjusted to above -0.06 MPa to allow the solvent to evaporate slowly and avoid loss of target hydrocarbon components through azeotropic distillation. After initial concentration, the remaining solution was transferred to a sample vial and purged with high-purity nitrogen at 30 °C to further concentrate the initially concentrated oil inclusion extract. The final volume was adjusted to 0.3–0.7 mL to obtain a concentrated oil inclusion extract suitable for instrumental analysis.

[0074] The concentrated extract of oil inclusions was analyzed using gas chromatography-mass spectrometry (GC-MS): an Agilent 8890 GC was used, equipped with an HP-5MS UI capillary column (60 m × 0.25 mm × 0.25 μm), with high-purity helium as the carrier gas and a flow rate of 1.00 mL / min; the mass spectrometer employed an electron impact (EI) ionization source with an ionization energy of 70 eV and an ionization source temperature of 230 °C, using a temperature-programmed method to separate the hydrocarbon components. Qualitative and quantitative analyses of geochemical parameters such as saturated hydrocarbons and aromatics in the oil inclusions were performed by comparing with a standard spectral library and identifying characteristic ions of biomarkers such as m / z 217 and m / z 191.

[0075] Analysis results as follows Figure 8 and Figure 9 As shown, the saturated hydrocarbon biomarker compounds in the oil inclusions of the K1y and K1bs reservoirs in a certain gas field exhibit highly consistent characteristics: n-alkanes nC 17 and nC 18 The relative abundance was significantly higher than that of phytane (Ph) and pterostilbene (Pr); C in the tricyclic terpenoid series 19 TT abundance was generally lower than C. 23 TT; C in the hopane series30 hopane (C 30 H) was abundant, while gammacerane (Ga) and C were abundant. 30 rearranged hopane (C 30 Diahopane was less abundant; regular sterane C 27 ααα20R–C 28 ααα20R–C 29 ααα20R exhibits a typical "V"-shaped distribution, and C 27 / C 29 The ααα20R ratio is relatively high. For example... Figure 10 , Figure 11 , Figure 12 and Figure 13 As shown, the cross-plot of multi-parameter biomarkers indicates that the oil inclusion sample points of the two reservoirs are densely distributed and highly overlapping, confirming that the crude oil in the K1y and K1bs reservoirs are homologous and both originate from the same source rock.

[0076] The homogenization temperature data of brine inclusions from each phase are projected onto the corresponding stratigraphic and thermal evolution maps. The corresponding geological ages are then read from the burial history maps, thus accurately determining the charging time of each phase of crude oil. For example... Figure 14 As shown, blue fluorescent oil was injected into the K1y reservoir during the depositional period of the Jidike Formation (23.3~19.8 Ma) and into the upper K1bs reservoir during the depositional period of the Kangcun Formation (15~5.3 Ma). Since the crude oil in the K1y and K1bs reservoirs has the same origin, both originating from the same source rock, combined with the tectonic evolution history of the work area, it can be seen that the oil generated by the source rock of the Triassic Huangshanjie Formation was preferentially injected into the lower K1y reservoir during the depositional period of the Jidike Formation (23.3~19.8 Ma). Subsequently, during the depositional period of the Kangcun Formation (15~5.3 Ma), driven by the Himalayan orogeny, the fault system was reactivated, and the ancient oil that had accumulated in the K1y reservoir underwent vertical adjustment and interlayer migration along the faults, and was injected into the upper K1bs reservoir. At this time, the crude oil in the K1y and K1bs reservoirs has a clear inheritance relationship and the same origin. Therefore, through multi-parameter analysis of fluid inclusions, the complete dynamic evolution sequence of crude oil charging time and adjustment and transformation of a gas field was accurately reconstructed, and the process of blue fluorescent oil adjustment and transformation of a gas field was clarified.

[0077] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for multi-stage adjustment and stimulation of oil reservoirs based on multi-parameter identification of fluid inclusions, characterized in that, Specifically, the steps include the following: S1, collect core samples from the target formation and prepare fluid inclusion thin sections; S2, Fluorescence microscopy was used to observe the fluid inclusions in thin sections, quantitative fluorescence analysis was performed on the selected oil inclusions, and the homogenization temperature of the brine inclusions was determined. S3, pretreatment of oil inclusions for extraction and preparation of core samples; S4, the oil inclusions are crushed, extracted, separated and purified to obtain the concentrated oil inclusion extract; S5, the oil inclusion extract to be concentrated is concentrated and the concentrated oil inclusion extract is analyzed by gas chromatography-mass spectrometry; S6, calibrate the charging period and establish a time series of crude oil charging and adjustment.

2. The method for multi-stage adjustment and stimulation of reservoirs based on multi-parameter identification of fluid inclusions according to claim 1, characterized in that, The specific process of step S1 is as follows: Collect core samples from different strata and structural locations in complex structural areas, and cut and grind the selected core samples on both sides to form fluid inclusion thin sheets.

3. The method for multi-stage adjustment and stimulation of reservoirs based on multi-parameter identification of fluid inclusions according to claim 1, characterized in that, The specific process of step S2 is as follows: S2.1, Fluorescence microscopy was performed on the prepared fluid inclusion thin sections to identify the occurrence, distribution and fluorescence spectral characteristics of oil inclusions in different phases; S2.2, Select oil inclusions for quantitative fluorescence analysis, obtain the maximum main peak wavelength λmax, and establish a fluorescence spectrum database of oil inclusions in different phases; S2.3, Identify gas-liquid two-phase brine inclusions that were captured concurrently with oil inclusions based on occurrence relationship, host mineral growth sequence and phase characteristics; S2.4, Homogenization temperature was measured using a geological hot and cold stage to record the temperature at which the gas-liquid two-phase brine inclusions were homogenized into the liquid phase; S2.5, through statistical analysis, the homogeneous temperature main peak range of brine inclusions in each period is obtained, and the crude oil charging period of different layers is divided by combining fluorescence spectral characteristics.

4. The method for multi-stage adjustment and stimulation of reservoirs based on multi-parameter identification of fluid inclusions according to claim 1, characterized in that, The specific process of step S3 is as follows: Based on the results of fluorescence microscopy and quantitative fluorescence analysis in S2, the host mineral type, particle size distribution and abundance of oil inclusions in each phase were identified, and the grinding mesh of the core samples was determined. 20-30g of core samples with only single-phase oil injection were weighed and ground to the predetermined mesh size using a pollution-free agate mortar at room temperature to obtain rock particle samples.

5. The method for multi-stage adjustment and stimulation of reservoirs based on multi-parameter identification of fluid inclusions according to claim 1, characterized in that, The specific process of step S4 is as follows: S4.1 Place the rock particle sample obtained in S3 in a clean beaker and wash it with 10%~15% hydrogen peroxide, 5%~10% dilute hydrochloric acid and aqua regia in sequence. Then use dichloromethane and methanol for ultrasonic cleaning to remove free hydrocarbons and contaminants attached to the surface of the rock particles. S4.2, Collect the last washing liquid and perform component analysis using gas chromatography-mass spectrometry to ensure that there are no hydrocarbon residues on the surface of the rock particles. Then, transfer the washed rock particle sample to the crushing device, add chromatographically pure solvent, and ensure that the solvent level is above the particles. Use a multi-stage crushing process to crush the particles, each time for 5 to 10 minutes. S4.3, transfer all the fine rock particles and solution in the crushing device to a clean beaker for ultrasonic-assisted extraction to fully dissolve the hydrocarbons remaining on the surface of the rock particles; S4.4 After standing, take the solvent of the upper layer containing oil inclusions extract, remove the suspended rock debris, and collect the filtrate in a clean round-bottom flask to obtain the oil inclusion extract to be concentrated.

6. The method for multi-stage adjustment and stimulation of reservoirs based on multi-parameter identification of fluid inclusions according to claim 1, characterized in that, The specific process of step S5 is as follows: S5.1, The oil inclusion extract obtained in step S4 is placed in a rotary evaporator for preliminary concentration. The vacuum degree is adjusted to above -0.06MPa to allow the solvent to evaporate slowly, and the oil inclusion extract is obtained after preliminary concentration. S5.2, the pre-concentrated oil inclusion extract is transferred to a sample vial and purged with high-purity nitrogen at 30°C to further concentrate the pre-concentrated oil inclusion extract. The final volume is adjusted to 0.3~0.7mL to obtain a concentrated oil inclusion extract suitable for instrumental analysis. S5.3, Gas chromatography-mass spectrometry was used to analyze the concentrated extract of oil inclusions. The chromatographic column was an HP-5MS capillary column or a DB-5MS capillary column, and the carrier gas was high-purity helium. The hydrocarbon components were separated by temperature program. The mass spectrometry used an electron impact ion source and acquired data in full scan or selected ion monitoring mode. S5.4, qualitative and quantitative analysis of geochemical parameters, including: n-alkanes, isoprene-like alkanes, steranes, terpenes and aromatics in oil inclusions.

7. The method for multi-stage adjustment and stimulation of reservoirs based on multi-parameter identification of fluid inclusions according to claim 1, characterized in that, The specific process of step S6 is as follows: S6.1 Project the homogenization temperature data of brine inclusions in each period onto the burial history and thermal history evolution map of the corresponding strata, and read the corresponding geological age on the burial history map; S6.2, by comparing the geochemical characteristics of oil extracts, the source of oil and gas is identified, and the time of oil and gas charging is determined by combining fluid inclusions with burial history. Finally, the time series of crude oil charging and adjustment is determined.

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