Method for monitoring and controlling microbial single-well huff and puff by using crude oil chromatographic parameters

Abstract

The application discloses a method for monitoring and controlling single-well microbial huff and puff by using crude oil chromatographic parameters, which comprises the following steps: (1) screening oil wells; (2) screening an activator system suitable for the growth of oil production function microorganisms; (3) carrying out indoor oil displacement model test to determine the oil displacement effect of the activated oil production function microorganisms; (4) performing total hydrocarbon gas chromatographic analysis on the crude oil of the oil well activated by the activator system screened in the step (2) to obtain parameters reflecting the effective action of the oil production microorganisms on the crude oil of the oil well; (5) determining the relationship between the soak time and the parameters reflecting the effective action of the oil production microorganisms on the crude oil of the oil well; (6) determining the relationship between the production time and the parameters reflecting the effective action of the oil production microorganisms on the crude oil of the oil well; (7) adjusting the oil well according to the soak time determined in the step (5) and the production time determined in the step (6), and then adjusting the secondary microbial huff and puff according to the monitoring result of the oil well.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of tertiary oil recovery, and particularly relates to a method for monitoring and regulating microbial single-well huff and puff by using crude oil chromatographic parameters. BACKGROUND

[0002] Microbial single-well huff and puff technology is a technology of injecting oil production functional microorganisms and / or activator systems into single-well reservoirs and improving single-well productivity by using the propagation and metabolism of oil production functional microorganisms in reservoir environments. As an environmentally friendly, low-cost and sustainable oil production technology, microbial single-well huff and puff technology provides a new technical option for oilfield development and has broad application prospects. After the production of the oil well is opened for a period of time, the oil well production will gradually weaken. In order to further tap the potential of microbial single-well huff and puff, microbial secondary huff and puff or even microbial multi-cycle huff and puff can be carried out, so as to effectively improve the single-well productivity.

[0003] Xu Enjin, Li Mu, et al. disclosed the screening, evaluation and field application of huff and puff bacteria in the article "Research on Multi-cycle Huff and Puff Technology of Heavy Oil Microorganisms", and achieved certain huff and puff effect, but had the following shortcomings and deficiencies: (1) The huff and puff bacteria used by the oil well are all selected from exogenous microorganism strains, which need to be fermented on the ground before being injected into the reservoir, thereby increasing the construction cost; (2) The compatibility of the selected exogenous microorganisms with endogenous microorganisms in the reservoir ecosystem is questionable, and the oil reservoir adaptability evaluation of the exogenous microorganisms is lacking; (3) The nutrient system is injected into the reservoir to provide nutrition for the propagation and metabolism of the exogenous microorganisms, but the screening and evaluation research of the nutrient system are lacking; (4) The concentration change of the microorganisms in the reservoir environment is taken as the evaluation index of the secondary huff and puff, and when the concentration of the microorganisms in the huff and puff output liquid of the oil well is reduced to 10 4 4

[0004] The Chinese patent application with the patent application number 201811119953.4 and the invention name "A method for single-well huff and puff oil production by using endogenous microorganisms" discloses a method for improving the single-well huff and puff production by using endogenous microorganisms, which comprises the following steps: screening of test oil wells; screening of activating agents; determination of the injection amount of activating agents; determination of the shut-in time; field test and evaluation of test results. The screening of endogenous activating agents is mainly carried out for different oil layers at different temperatures, so that the selected activating agent formula can effectively activate the endogenous microorganisms in different oil layers of the test oil well. The method has the following disadvantages: (1) the abundance of endogenous microorganisms in different reservoirs is different, and the endogenous microorganisms in some reservoirs are scarce, which limits the application of single-well huff and puff oil production by using endogenous microorganisms; (2) the emulsification index and the bacterial concentration are used as the main evaluation indexes of the activation effect of the endogenous microorganisms in the reservoir, but there is a lack of physical simulation of the oil displacement of the activated endogenous microorganisms in the reservoir, which makes it impossible to effectively judge the oil displacement potential of the injected microorganisms in the reservoir environment, thereby increasing the risk of field huff and puff implementation; (3) the evaluation indexes and huff and puff adjustment scheme of the target oil well are missing, so that the subsequent field huff and puff test cannot be carried out.

[0005] In addition, whether to carry out the second huff and puff by using microorganisms is usually determined according to the changes of the oil increment and the water cut in the oil well. When there is no significant oil increment effect and the water cut of the oil well after the implementation of the single-well huff and puff by using microorganisms rises close to the value before the implementation, it is decided to carry out the second huff and puff by using microorganisms. The dynamic monitoring and control has a serious lag for the huff and puff by using microorganisms, so that the oil well is in a low-speed oil production period for a long time, and it is difficult to effectively exert the best benefits of the oil well production. SUMMARY

[0006] The present application provides a method for monitoring and controlling the single-well huff and puff by using microorganisms by using the chromatographic parameters of crude oil. The method has simple implementation process, strong pertinence and good controllability, and effectively improves the application effect of the microorganism oil production technology in the single-well huff and puff.

[0007] The present application fully utilizes the action characteristics of microorganisms on crude oil, analyzes the whole hydrocarbon chromatographic data of crude oil, screens the markers of different carbon numbers reflecting the change rule of the composition of crude oil, and then uses the peak area ratio of the markers as the marker parameters to determine the best soak time and the best opening time of the single-well huff and puff by using microorganisms, and the monitoring result of the marker parameters is used to control the single-well huff and puff by using microorganisms, which is a new method for quickly, effectively and sensitively characterizing the huff and puff effect by using microorganisms and predicting the adjustment of the second huff and puff.

[0008] The method for monitoring and controlling the single-well huff and puff by using microorganisms disclosed by the present application comprises the following steps, but is not limited to the following steps:

[0009] First, select suitable oil wells;

[0010] Then, based on the activation status of oil-producing microorganisms in the oil well, it is determined whether to add more oil-producing microorganisms, and the oil production potential of the activated microorganisms is determined through indoor physical model oil displacement experiments.

[0011] Then, the crude oil after activation by microorganisms was subjected to full hydrocarbon gas chromatography analysis. By comparison, marker components characterizing microbial-specific degradation were selected. The sum of the chromatographic peak areas of five marker components with a carbon number less than 20 was compared with C1 to C2. 30 By comparing the sum of the total areas of the component chromatographic peaks, parameters reflecting the effective effect of oil-producing microorganisms on crude oil in oil wells can be obtained;

[0012] Based on this, the optimal well-closing time was determined by optimizing the relationship between well-closing time and crude oil characteristic chromatographic parameters in the microbial huff and puff field.

[0013] After the well is shut down and production resumes, the correlation between production time and crude oil characteristic chromatographic parameters is used to determine the next steps for adjusting single-well measures, thereby further improving the microbial single-well huff and puff effect.

[0014] Technical solution: A method for monitoring and regulating microbial huff and puff in a single well using crude oil chromatographic parameters, comprising the following steps:

[0015] (1) Screening oil wells;

[0016] (2) Screening an activator system suitable for the growth of oil-producing microorganisms;

[0017] (3) Conduct indoor physical model oil displacement tests to determine the oil displacement effect of activated oil-producing microorganisms;

[0018] (4) Take the crude oil from the oil well after activation by the activator system screened in step (2) and perform full hydrocarbon gas chromatography analysis to obtain parameters reflecting the effective effect of oil production microorganisms on crude oil in the oil well.

[0019] (5) Determine the relationship between the well shut-in time and the parameters reflecting the effective effect of oil production microorganisms on crude oil in the well;

[0020] (6) Determine the relationship between production time and parameters reflecting the effective effect of oil-producing microorganisms on crude oil in oil wells;

[0021] (7) Adjust the oil well according to the well simmering time determined in step (5) and the production time determined in step (6), and then adjust the secondary microbial ingestion and expulsion according to the oil well monitoring results.

[0022] Furthermore, the criteria for selecting oil wells in step (1) are: reservoir temperature < 100℃, permeability > 10×10⁻⁶. -3 μm2 Formation water salinity < 80,000 mg / L, crude oil viscosity < 10,000 mPa·s, and possessing at least two types of oil recovery microorganisms with a concentration ≥ 10 2 The oil recovery microorganisms are one of the following: denitrifying bacteria, anaerobic bacteria, oleophilic bacteria, Bacillus, Pseudomonas, Alcaligenes, Rhodococcus, Short bacilli, Dist., and Clostridium.

[0023] Furthermore, step (2) includes the following steps:

[0024] (21) Through single-factor experiments, using the concentration of activated microorganisms as an indicator, the components of the activation system that can effectively activate microorganisms in oil wells, including carbon source, nitrogen source, phosphorus source and growth factor, were determined.

[0025] (22) via L93 4 An orthogonal experiment was conducted using four factors and three levels. The concentration of activated microorganisms and the proportion of oil-producing microorganisms were used as indicators to optimize and determine the optimal activator system for effectively activating oil-producing microorganisms in oil wells, as shown in Table 1 below:

[0026] Table 1. Factor Levels in the Orthogonal Experiment of the Activator System

[0027] Horizontal Carbon source (g / L) Nitrogen source (g / L) Phosphorus source (g / L) Growth factor (g / L) 1 5 10 1 0.1 2 10 30 3 0.5 3 20 50 5 1

[0028] The activator system contains 5–20 g / L carbon source, 10–50 g / L nitrogen source, 1–5 g / L phosphorus source, and 0.1–1 g / L growth factor.

[0029] Furthermore, in step (21), the carbon source is one of sucrose, glucose, or molasses.

[0030] Furthermore, in step (21), the nitrogen source is one of monosodium glutamate, ammonium nitrate, sodium nitrate, ammonium chloride, soybean meal hydrolysate, corn flour hydrolysate, or starch hydrolysate.

[0031] Furthermore, in step (21), the phosphorus source is one of sodium polyphosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, or disodium hydrogen phosphate.

[0032] Furthermore, the growth factor in step (21) is one of the following: methionine, yeast extract, mannitol, xylitol, p-hydroxytoluene, or small molecule peptide.

[0033] Furthermore, step (3) includes the following steps:

[0034] (31) Determine the microbial concentration of a set of tests for the optimal activator system finally determined in step (22). If the concentration of microorganisms is ≥10 8If the number of copies / mL is less than 3, proceed to step (32); otherwise, end the operation.

[0035] (32) Determine the proportion of oil recovery functional microorganisms in a set of tests of the optimal activator system finally determined in step (22). If it is ≥55%, proceed to step (34); otherwise, proceed to step (33).

[0036] (33) Add the oil-producing functional microbial fermentation broth to the optimal activator system finally determined in step (22), and then reactivate the fermentation system in step (31). At this time, if the proportion of oil-producing functional microorganisms is ≥55%, proceed to step (35); otherwise, end the operation.

[0037] Among them: the concentration of oil-producing microorganisms in the oil-producing microbial fermentation broth is 10. 8 ~10 9 copies / mL;

[0038] The volume ratio of the oil recovery functional microbial fermentation broth to the optimal activator system finally determined in step (22) is (5-20):100;

[0039] (34) Conduct physical simulation oil displacement experiments:

[0040] (341) Fill the rock core, vacuum saturate the formation water, and measure the porosity and permeability parameters;

[0041] (342) Saturate the oil and calculate the original oil saturation;

[0042] (343) One water drive to the core produced fluid with a water content of more than 95%;

[0043] (344) Inject 0.3PV of the activator system selected in step (2) and incubate at reservoir temperature for 10-15 days;

[0044] (345) Finally, perform a second water flooding to 100% water content and calculate the oil displacement effect; if the crude oil recovery rate increases by ≥15%, proceed to step (4); otherwise, end the operation.

[0045] (35) Conduct physical simulation oil displacement experiments:

[0046] (351) Fill the rock core, vacuum saturate the formation water, and measure the porosity and permeability parameters;

[0047] (352) Saturate the oil and calculate the original oil saturation;

[0048] (353) One water drive to produce core fluid with a water content of over 95%;

[0049] (354) Inject 0.3PV of the activator system selected in step (2) and the mixture of the fermentation broth of the oil-producing microorganisms, and let it stand at the reservoir temperature for 10-15 days;

[0050] (345) Finally, perform a second water flooding to 100% water content and calculate the oil displacement effect; if the crude oil recovery rate increases by ≥15%, proceed to step (4); otherwise, end the operation.

[0051] Furthermore, in step (4), the full hydrocarbon gas chromatography analysis refers to screening and identifying five relatively high peak values ​​with a carbon number less than 20 that can reflect the change law of crude oil composition after the action of oil-producing microorganisms through the full hydrocarbon gas chromatogram of crude oil. These components have the characteristics of significant changes and easy identification. Finally, parameters that can characterize the effect of crude oil in oil wells are determined.

[0052] Furthermore, the parameter characterizing the effect of crude oil in oil wells refers to the five highest peaks (C50, C60, C70, C80, C90, C90, C90, C90) of the marker components. a C b C c C d C e The sum of the areas and C1 to C 30 By comparing the sum of the total peak areas of the components, a parameter reflecting the effective effect of oil-producing microorganisms on crude oil from oil wells is obtained: C a +C b +C c +C d +C e / ∑C 30 .

[0053] Furthermore, the relationship between the well-sinking time mentioned in step (5) and the parameter reflecting the effective effect of oil-producing microorganisms on crude oil in the oil well refers to:

[0054] The activator system selected in step (2) was injected into the oil well at the microbial huff and puff site, and the well was kept simmered to allow it to fully multiply for different periods of time. The simmering time, the number of microorganisms, and the parameter C reflecting the effective effect of the oil-producing microorganisms on the crude oil were continuously monitored. a +C b +C c +C d +C e / ∑C 30 Based on the correlation characteristics between them, the optimal well shut-in time is determined by optimizing the monitoring results. The well shut-in time index must simultaneously meet the following conditions:

[0055] The concentration of activated microorganisms is ≥10. 7 copies / mL;

[0056] C a +Cb +C c +C d +C e / ∑C 30 ≥20%.

[0057] Furthermore, the injection volume V of the activator system selected in step (2) + oil recovery function microbial fermentation fluid injected into the oil well at the microbial huff and puff site is calculated according to the following formula:

[0058] V = 3.14r 2 HФβ

[0059] Where: V—the amount of activator injected into the system, m 3 ;

[0060] r—processing radius, m, with a value range of 8 to 10;

[0061] H—Effect thickness of high-permeability oil layer, m;

[0062] Ф—Porosity of the oil layer, dimensionless;

[0063] β—Dosage coefficient, dimensionless, with a value range of 0.6 to 0.8.

[0064] When C a +C b +C c +C d +C e / ∑C 30 ≤5% indicates that the injected microbial system has not been effective in this oil well, and the contact efficiency between the activated microorganisms and crude oil is low. Further research should be conducted to increase the contact area between the injected system and crude oil.

[0065] Furthermore, the relationship between the production time mentioned in step (6) and the parameter reflecting the effective effect of oil-producing microorganisms on crude oil in the oil well refers to:

[0066] After meeting the well-clogging time requirements for microbial single-well huff and puff application in step (5) above, the well is opened for production.

[0067] Then, on-site sampling was conducted to continuously monitor well production time, daily oil increase, and chromatographic parameter C. a +C b +C c +C d +C e / ∑C 30 The correlation characteristics between them;

[0068] The optimal production time is determined based on monitoring results.

[0069] Furthermore, in step (6), when the oil well monitoring indicators simultaneously meet the following conditions: peak daily oil production increase of a single well ≥ 3t, C a +C b +C c +C d +C e / ∑C 30 When the percentage is greater than 5%, maintain normal production of the oil well.

[0070] Furthermore, the results of the dynamic monitoring of the oil well in step (7) can be categorized into three types:

[0071] (a) Well start-up production time of churn-and-puff wells ≤ 20 days, C a +C b +C c +C d +C e / ∑C 30 If the concentration is ≤5%, it indicates that the microbial injection system is not suitable for field application requirements, and a more suitable microbial injection system should be obtained after further research.

[0072] (b) When 30d ≤ well start-up production time of the churn well ≤ 180d, C a +C b +C c +C d +C e / ∑C 30 When the percentage is ≤5%, it indicates that the microbial injection system is suitable for field application requirements and has a certain microbial single-well huff and puff effect. However, the huff and puff effective period needs to be further extended. In the next step, the single-well huff and puff oil enhancement effect of microorganisms can be further improved by optimizing and increasing the well simmering time or the injection volume of the microbial system.

[0073] (c) When the well-starting production time of the churn well is >180 days, C a +C b +C c +C d +C e / ∑C 30 When the percentage is ≤5%, it indicates that the microbial injection system is suitable for field application requirements, and the single-well microbial huff and puff effect is significant. The original system injection process can be continued for secondary microbial huff and puff applications in the field.

[0074] In this application document: C a +C b +C c +C d +C e / ∑C 30 This indicates that the peaks of the five or fewer carbons less than 20 are relatively high, representing the five or fewer characteristic component chromatographic peaks. a C b Cc C d C e The sum of the areas and C1 to C 30 Compare the sum of the total peak areas of each component. C a +C b +C c +C d +C e It can represent 1, 2, 3, 4, or 5 marker component chromatographic peaks.

[0075] Compared with existing technologies, the method for monitoring and regulating microbial single-well huff and puff using crude oil chromatographic parameters disclosed in this invention has the following advantages and beneficial effects:

[0076] (1) This invention is based on the method of gas chromatography analysis of crude oil full hydrocarbons. It is applicable to the field dynamic monitoring of single-well huff and puff of all microorganisms. It has the characteristics of simple operation, high sensitivity and strong reliability.

[0077] (2) This invention makes full use of the special oil fingerprint of microorganisms, which can not only predict and regulate the optimal well simmering time and optimal production time of microbial single well huff and puff, but also make directional adjustments to the subsequent microbial secondary huff and puff measures based on the field monitoring results.

[0078] (3) This invention solves the problems caused by the previous microbial single-well huff and puff field monitoring data being too reliant on indirect biological indicators, which led to difficulties in controlling the optimal well shut-in time and optimal production time, and the lag in secondary huff and puff adjustments. This invention adopts direct biological indicators of crude oil action, which greatly improves the controllability and effectiveness of on-site dynamic adjustments. Attached Figure Description

[0079] Figure 1 This is a flowchart of a method for monitoring and regulating microbial huff and puff in a single well using crude oil chromatographic parameters, as disclosed in this invention.

[0080] Figure 2 This is a chromatogram of the total hydrocarbons in crude oil after microbial action in oil well A in Example 1.

[0081] Figure 3 This is a chromatogram of the total hydrocarbons in crude oil after microbial action in oil well D in Example 2.

[0082] Figure 4 This is a chromatogram of the total hydrocarbons in crude oil after microbial action in oil well F in Example 3.

[0083] Figure 5 This is a chromatogram of the total hydrocarbons in crude oil after microbial action in oil well G in Example 4. Detailed Implementation

[0084] The specific embodiments of the present invention are described in detail below.

[0085] The endpoints and any values ​​of the ranges disclosed in this application are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. With regard to numerical ranges, the endpoint values ​​of each range, and the endpoint values ​​of each range with individual point values, can be gradually combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this application.

[0086] Example 1: Taking well A in Shengli Oilfield as an example

[0087] A method for monitoring and regulating microbial huff and puff in a single well using crude oil chromatographic parameters includes the following steps:

[0088] (1) Screening oil wells:

[0089] Oil well A has a reservoir temperature of 55℃, crude oil viscosity of 1850 mPa·s, formation water salinity of 2260 mg / L, and permeability of 1300 × 10⁻⁶. -3 μm 2 The effective thickness of the oil layer is 6.9 m, and the porosity is 0.30. Before the implementation of microbial single-well huff and puff, the oil production rate was 0.5 t / d, the liquid production rate was 2 t / d, and the water cut was 75%. Based on the population structure analysis of the oil well microorganisms, the types of oil-producing functional microorganisms were determined to be denitrifying bacteria and anaerobic bacteria, and the reservoir microbial concentration was 220 copies / mL, which met the well selection conditions, as shown in Table 2.

[0090] Table 2. Reservoir microbial analysis in well A

[0091] Category Denitrifying bacteria, anaerobic bacilli Reservoir microbial concentration (copies / mL) 220

[0092] (2) Screening an activator system suitable for the growth of oil-producing microorganisms

[0093] First, the concentrations of carbon source, nitrogen source, phosphorus source, and growth factor were fixed, and single-factor optimization experiments were conducted on these components.

[0094] The single-factor optimization results of the activator system in Tables 3 to 6 show that molasses is the best carbon source compared to glucose and sucrose.

[0095] Compared with monosodium glutamate, ammonium nitrate, sodium nitrate, ammonium chloride, corn flour hydrolysate and starch hydrolysate, soybean meal hydrolysate is the best nitrogen source;

[0096] Compared to sodium polyphosphate, ammonium dihydrogen phosphate, and disodium hydrogen phosphate, diammonium hydrogen phosphate is the best phosphorus source.

[0097] Compared to methionine, yeast extract, mannitol, p-hydroxytoluene, and small molecule peptides, xylitol is the best growth factor.

[0098] Table 3 Single-factor experiments with different carbon sources for the activator system.

[0099] Carbon source 5 g / L Microbial concentration copies / mL Sucrose 1.3 x 10 8 ]]> Glucose 1.8 x 10 8 ]]> Molasses 2.0 x 10 8 ]]>

[0100] Table 4 Single-factor experiments with different nitrogen sources for the activator system.

[0101] Nitrogen source 10 g / L Microbial concentration copies / mL Sodium glutamate 2.0 x 10 8 ]]> Ammonium nitrate 2.2 x 10 8 ]]> Sodium nitrate 1.8 x 10 8 ]]> Ammonium chloride 2.6 x 10 8 ]]> Soybean hydrolysate 3.8 x 10 8 ]]> Corn powder hydrolysate 2.9 x 10 8 ]] Starch hydrolysate 2.5 x 10 8 ]]>

[0102] Table 5 Single-factor experiments with different phosphorus sources for the activator system.

[0103] Phosphorus source 1 g / L Microbial concentration copies / mL Sodium polyphosphate 3.5 x 10 8 ]]> Ammonium dihydrogen phosphate 3.3 x 10 8 ]]> Diammonium hydrogen phosphate 4.0 x 10 8 ]] Disodium hydrogen phosphate 3.8 x 10 8 ]]>

[0104] Table 6 Single-factor experiments with different growth factors in the activator system.

[0105] Growth factor 0.1 g / L Microbial concentration copies / mL Methionine 4.1 x 10 8 ]]> Yeast powder 3.6 x 10 8 ]]> Mannitol 4.4 x 10 8 ]]> Xylitol 5.0 x 10 8 ]]> p-Hydroxytoluene 3.6 x 10 8 ]]> Small molecule peptide 4.0 x 10 8 ]]>

[0106] Then, the concentration of the components in the activator system, consisting of molasses, soybean meal hydrolysate, diammonium hydrogen phosphate, and xylitol, was further optimized to design L93. 4 An orthogonal experiment was conducted using a 4-factor, 3-level model. The optimal activator system for effectively activating denitrifying bacteria and anaerobic bacteria in oil wells was determined, with the concentration of activated microorganisms and the proportion of oil-producing microorganisms as indicators. The results are shown in Table 7. System #5, consisting of molasses 10 g / L, soybean meal hydrolysate 30 g / L, diammonium hydrogen phosphate 5 g / L, and xylitol 0.1 g / L, was the optimal activator system, resulting in a microbial concentration of 5.8 × 10⁻⁶. 8 The population of oil-producing functional microorganisms, including denitrifying bacteria and anaerobic bacteria, accounts for 63% of the total population, giving them a dominant position in the microbial ecosystem.

[0107] Table 7 Statistical results of orthogonal optimization experiments for the activator system

[0108]

[0109]

[0110] (3) Using the activator system screened above, an indoor physical model oil displacement experiment was conducted, specifically including the following steps:

[0111] (31) The microbial concentration of the 5# activator system in step (22) is ≥10 8 If copies / mL, proceed to step (32);

[0112] (32) The proportion of oil recovery functional microorganisms in the No. 5 activator system in step (22) is 60% or ≥55%, then proceed to step (34);

[0113] (34) Conduct physical simulation oil displacement experiments:

[0114] (341) Fill the rock core, vacuum saturate the formation water, and measure the porosity and permeability parameters;

[0115] (342) Saturate the oil and calculate the original oil saturation;

[0116] (343) One water drive to the core produced fluid with a water content of more than 95%;

[0117] (344) Inject 0.3PV5# activator system and incubate statically at reservoir temperature for 15 days;

[0118] (345) Finally, perform a second water flooding to 100% water content and calculate the oil displacement effect; if the crude oil recovery rate increases by ≥15%, proceed to step (4); otherwise, end the operation.

[0119] As can be seen from the core displacement results in Table 8, the injection of 0.3PV of the No. 5 activator system can activate reservoir microorganisms and increase crude oil recovery by 16.5%, demonstrating the potential for single-well huff and puff using reservoir endogenous microorganisms.

[0120] Table 8. Microbial enhanced oil recovery effect of oil well A

[0121]

[0122] (4) Take the optimal activator system screened in step (2) to fully activate the oil-producing microorganisms, and perform full hydrocarbon gas chromatography analysis on the crude oil after their action to obtain parameters reflecting the effective effect of the oil-producing microorganisms on the crude oil of the oil well.

[0123] Gas chromatography analysis of crude oil after the action of oil-producing microorganisms revealed degradation of heavy components and C. 20 The light hydrocarbon component of the crude oil had previously increased. Gas chromatography was used to screen and identify marker components that could reflect the changes in crude oil composition after microbial activity: C8, C... 10 C 15 The peak areas of three markers and their correlation with C1 to C2 were analyzed. 30 By comparing the chromatographic peak areas, the monitoring parameters characterizing the microbial swallowing and purging effect were obtained: C8+C 10 +C 15 / ∑C 30 The specific details of the chromatogram are as follows: Figure 2 As shown.

[0124] (5) Determine the relationship between the well shut-in time and the parameters reflecting the effective effect of oil production microorganisms on crude oil in oil wells;

[0125] First, the activator system is injected into oil well A through the annulus of the casing and sleeve. The injection volume is:

[0126] V = 3.14r 2 HФβ=3.14×8 2 ×6.9×0.3×0.6=250m 3

[0127] Where r1 takes the value 8 and β1 takes the value 0.6.

[0128] Then, the well was shut in to allow the microorganisms in the reservoir to grow and multiply effectively, and to fully interact with the crude oil. After shutting in the well for different periods of time, such as 5 days, 8 days, 10 days, 12 days, 15 days, and 18 days, the well was opened and samples were taken for index monitoring. The specific monitoring results are shown in Table 9.

[0129] Table 9. Optimization results of monitoring the shut-in time of oil well A

[0130]

[0131]

[0132] Based on the above-mentioned well-steaming time, microbial concentration, and C8+C 10 +C 15 / ∑C 30 The correlation characteristics among the characteristic chromatographic parameters of crude oil determined that the optimal shut-in time for microbial huff and puff in oil well A was 18 days, at which time the concentration of activated microorganisms was 2.8 × 10⁻⁶. 7 The value of the characteristic chromatographic parameter, copies / mL, is 20%, which meets the well opening time requirement.

[0133] (6) Determine the relationship between production time and parameters reflecting the effective effect of oil-producing microorganisms on crude oil in oil wells;

[0134] Oil well A was shut down for 18 days before being reopened for normal production. Samples were taken at different times to compare daily oil and C8+C levels. 10 +C 15 / ∑C 30 The crude oil's characteristic chromatographic parameters and other indicators were monitored to determine the optimal production time of the well, and the secondary microbial huff and puff measures were adjusted based on the monitoring results. The specific monitoring results are shown in Table 10.

[0135] Table 10 Optimization Results of Monitoring Production Time of Oil Well A

[0136]

[0137] The results above show that when oil well A is in normal production for 90 days, the daily oil production increase reaches 2.5t, C8+C 10 +C 15 / ∑C 30 The characteristic chromatographic parameter value of crude oil decreased slowly from 20% to 4%, indicating that the microbial injection system has a certain single-well huff and puff effect on oil well A.

[0138] (7) Adjust the oil well according to the well simmering time determined in step (5) and the production time determined in step (6), and then adjust the secondary microbial ingestion and expulsion according to the oil well monitoring results.

[0139] The changes in the oil well dynamic monitoring results fall into the second category. To further extend the effective period of single-well huff and puff, secondary microbial huff and puff adjustments are necessary. Subsequently, the effectiveness of secondary microbial huff and puff can be optimized and improved by increasing parameters such as well-closing time or the injection volume of the microbial system.

[0140] Example 2: Taking a certain oil well D in Shengli Oilfield as an example

[0141] A method for monitoring and regulating microbial huff and puff in a single well using crude oil chromatographic parameters includes the following steps:

[0142] (1) Screening oil wells;

[0143] The reservoir temperature of oil well D is 60℃, the crude oil viscosity is 980 mPa·s, the formation water salinity is 1360 mg / L, and the permeability is 1000 × 10⁻⁶. -3 μm 2 The effective thickness of the oil layer is 2.0 m, and the porosity is 0.22. Before the implementation of microbial single-well huff and puff, the oil production rate was 1.5 t / d, the liquid production rate was 10 t / d, and the water cut was 83%. Based on the population structure analysis of the oil well microorganisms, the types of oil-producing functional microorganisms were determined to be Bacillus, Pseudomonas, and Anaerobic Bacillus. The concentration of reservoir microorganisms was 500 copies / mL, which met the well selection conditions, as shown in Table 11.

[0144] Table 11 Reservoir Microbial Analysis in Well D

[0145] Category of oil production functional microorganisms Bacillus, Pseudomonas and anaerobic bacilli Reservoir microbial concentration (copies / mL) 500

[0146] (2) Screening an activator system suitable for the growth of oil-producing microorganisms

[0147] First, with the concentrations of carbon source, nitrogen source, phosphorus source, and growth factor fixed, single-factor optimization experiments were conducted on these components:

[0148] The single-factor optimization results of the activator system from Tables 12 to 15 show that:

[0149] Compared to glucose and molasses, sucrose is the optimal carbon source, and the activated microbial concentration is 3.3 × 10⁻⁶. 8 copies / mL;

[0150] Compared with monosodium glutamate, soybean meal hydrolysate, sodium nitrate, ammonium chloride, corn flour hydrolysate, and starch hydrolysate, ammonium nitrate is the optimal nitrogen source, with an activated microbial concentration of 3.9 × 10⁻⁶. 8 copies / mL;

[0151] Compared to sodium polyphosphate, ammonium dihydrogen phosphate, and disodium hydrogen phosphate, diammonium hydrogen phosphate is the optimal phosphorus source, with an activated microbial concentration of 4.2 × 10⁻⁶. 8 copies / mL;

[0152] Compared to methionine, xylitol, mannitol, p-hydroxytoluene, and small molecule peptides, yeast extract is the optimal growth factor, with an activated microbial concentration of 4.6 × 10⁻⁶. 8 copies / mL.

[0153] Table 12 Single-factor experiments with different carbon sources for the activator system.

[0154] Carbon source 5 g / L Microbial concentration copies / mL Sucrose 3.3 x 10 8 ]]> Glucose 2.0 x 10 8 ]]> Molasses 1.9 x 10 8 ]]>

[0155] Table 13 Single-factor experiments with different nitrogen sources for the activator system.

[0156] Nitrogen source 10 g / L Microbial concentration copies / mL Sodium glutamate 2.0 x 10 8 ]]> Ammonium nitrate 3.9 x 10 8 ]]> Sodium nitrate 1.8 x 10 8 ]]> Ammonium chloride 2.6 x 10 8 ]]> Soybean hydrolysate 1.8 x 10 8 ]]> Corn powder hydrolysate 2.9 x 10 8 ]]> Starch hydrolysate 3.0 x 10 8 ]]>

[0157] Table 14 Single-factor experiments with different phosphorus sources for the activator system

[0158] Phosphorus source 1 g / L Microbial concentration copies / mL Sodium polyphosphate 2.5 x 10 8 ]]> Ammonium dihydrogen phosphate 3.8 x 10 8 ]]> Diammonium hydrogen phosphate 4.2 x 10 8 ]]> Disodium hydrogen phosphate 3.6 x 10 8 ]]

[0159] Table 15 Single-factor experiments with different growth factors in the activator system.

[0160] Growth factor 0.1 g / L Microbial concentration copies / mL Methionine 3.1 x 10 8 ]] Yeast powder 4.6 x 10 8 ]]> Mannitol 3.4 x 10 8 ]]> Xylitol 4.0 x 10 8 ]]> p-Hydroxytoluene 3.6 x 10 8 ]] Small molecule peptide 2.0 x 10 8 ]]>

[0161] Then, the concentration of the activator system, consisting of sucrose, ammonium nitrate, diammonium hydrogen phosphate, and yeast powder, was further optimized to effectively activate the oil recovery microorganisms, including Bacillus, Pseudomonas, and anaerobic bacteria, in oil wells. The L93 design... 4 An orthogonal experiment was conducted using a 4-factor, 3-level model. The optimal activator system was determined by evaluating the concentration of activated microorganisms and the proportion of oil-producing functional microorganisms. The specific results are shown in Table 16. System #6, with sucrose 10 g / L, ammonium nitrate 50 g / L, diammonium hydrogen phosphate 1 g / L, and yeast powder 0.5 g / L, was the optimal activator system, resulting in a microbial concentration of 6.0 × 10⁻⁶. 8The population of oil-producing functional microorganisms, including Bacillus, Pseudomonas, and anaerobic bacteria, accounted for 50% of the total, indicating a lack of dominant population. Therefore, it is necessary to introduce exogenous oil-producing functional microbial fermentation broth to regulate and enhance their dominant position in the reservoir microbial ecosystem.

[0162] Table 16 Statistical results of orthogonal optimization experiments for the activator system

[0163]

[0164] Different concentrations of 2.0 × 10 8 A sample of oil recovery microbial fermentation broth at a concentration of copies / mL was introduced into the formation water sample of oil well D. After incubation for a period of time with the addition of activator #6, the optimal injection volume of the exogenous oil recovery microbial fermentation broth was determined by the proportion of oil recovery microorganisms. Table 17 shows that when the injection volume of the exogenous oil recovery microbial fermentation broth was 120 mL / L, the proportion of activated oil recovery microorganisms reached 65%, indicating that Bacillus, Pseudomonas, and anaerobic bacteria gradually transformed into dominant oil recovery microorganisms in the reservoir environment, which is beneficial for maximizing oil recovery.

[0165] Table 17 Optimization results of injection volume of microbial fermentation broth for oil recovery

[0166]

[0167] (3) Indoor model oil displacement experiments were conducted using the activator system selected above.

[0168] As can be seen from the core displacement results in Table 18, injecting 0.3PV of 6# activator system and 12% concentration of exogenous oil recovery functional microbial fermentation fluid can activate reservoir microorganisms and increase crude oil recovery rate by up to 20.0%, and has the potential to utilize reservoir endogenous microorganisms for single-well huff and puff.

[0169] Table 18 Microbial enhanced oil recovery effect of oil well D

[0170]

[0171] (4) Take the activator system screened and optimized in step (2) and the oil-producing functional microorganisms after being activated and regulated by the oil-producing functional microorganisms, and perform full hydrocarbon gas chromatography analysis to obtain parameters reflecting the effective effect of oil-producing microorganisms on oil well crude oil.

[0172] Gas chromatography analysis of crude oil from well D after microbial activity in the oil recovery system revealed degradation of heavy components and C. 20The light hydrocarbon component of the crude oil had previously increased. Gas chromatography was used to screen and identify marker components that could reflect the changes in crude oil composition after microbial activity: C6, C... 10 C 16 C 17 The sum of the peak areas of the four markers and C1 to C2 were used to determine their composition. 30 By comparing the sums of the chromatographic peak areas, the monitoring parameter characterizing the microbial swallowing and purging effect was obtained: C6+C 10 +C 16 +C 17 / ∑C 30 The specific details of the chromatogram are as follows: Figure 3 As shown.

[0173] (5) Determine the relationship between the well shut-in time and the parameters reflecting the effective effect of oil production microorganisms on crude oil in oil wells;

[0174] First, the activator system is injected into well D through the annulus of the casing, with the injection volume being:

[0175] V1 = 3.14r 2 HФβ=3.14×9 2 ×2.0×0.22×0.7=78.3m 3

[0176] Where r1 takes the value 9 and β1 takes the value 0.7.

[0177] Next, inject the oil recovery functional microbial fermentation broth, the injection volume of which is:

[0178] V2=V1×C=78.3×1000×0.12=9396L=9.396m 3

[0179] Where C is set to the optimized injection concentration of 12%.

[0180] 78.3m³ of oil was injected into well D through the annulus of the casing. 3 The 6# activator system and 9.396m 3 A mixed fermentation broth of Bacillus, Pseudomonas, and anaerobic bacteria was prepared, and then the well was shut in to allow the microorganisms in the reservoir environment to grow and multiply effectively, and to fully interact with the crude oil. Samples were taken and monitored at different times, such as 5, 10, 15, 20, 25, and 30 days after well shut-in. The specific results are shown in Table 19.

[0181] Table 19 Optimization Results of Monitoring the Shutdown Time of Oil Well D

[0182]

[0183] Based on the above-mentioned well-steaming time, microbial concentration, and C6+C10 +C 16 +C 17 / ∑C 30 The correlation characteristics among the characteristic chromatographic parameters of crude oil determined that the optimal shut-in time for microbial huff and puff in oil well D was 30 days, at which time the concentration of activated microorganisms was 5.8 × 10⁻⁶. 7 The number of copies / mL and the value of the characteristic chromatographic parameter were 22%, which met the requirements for well opening and well shut-in, thus ending the well shut-in process.

[0184] (6) Determine the relationship between production time and parameters reflecting the effective effect of oil production microorganisms on crude oil in oil wells;

[0185] Oil well D was shut down for 30 days before being reopened for normal production. Samples were taken at different times to analyze daily oil and C6+C content. 10 +C 16 +C 17 / ∑C 30 The crude oil's characteristic chromatographic parameters and other indicators were monitored to determine the optimal production time of the well, and the secondary microbial huff and puff measures were adjusted based on the monitoring results. The specific monitoring results are shown in Table 20.

[0186] Table 20 Optimization Results of Monitoring Production Time of Oil Well D

[0187]

[0188] The results above show that when oil well D is in normal production for 260 days, the daily oil production increase reaches 4.5t, C6+C 10 +C 16 +C 17 / ∑C 30 The characteristic chromatographic parameters of crude oil first rose to 25% and then decreased to 5%, indicating that the microbial injection system is suitable for field application requirements and the single-well huff and puff effect of microorganisms is significant.

[0189] (7) Adjust the oil well according to the well simmering time determined in step (5) and the production time determined in step (6), and then adjust the secondary microbial ingestion and expulsion according to the oil well monitoring results.

[0190] The results of the dynamic monitoring of the oil well fall into the third category. Next, we will continue to use the original microbial injection system and corresponding injection process to carry out the field application of microbial secondary single-well huff and puff.

[0191] Example 3: Taking a certain oil well F in Shengli Oilfield as an example

[0192] A method for monitoring and regulating microbial huff and puff in a single well using crude oil chromatographic parameters includes the following steps:

[0193] (1) Analysis of characteristic chromatographic parameters of crude oil after microbial action in oil wells:

[0194] The reservoir temperature of oil well F is 71℃, the crude oil viscosity is 2360 mPa·s, the formation water salinity is 8500 mg / L, and the permeability is 520 × 10⁻⁶. -3 μm 2 The effective oil layer thickness is 18.0 m, and the porosity is 0.32. Before the implementation of microbial single-well huff and puff, the oil production rate was 2.0 t / d, the liquid production rate was 50 t / d, and the water cut was 96%. Based on the population structure analysis of the oil well microorganisms, the species of oil-producing functional microorganisms were determined to be Pseudomonas and Alcaligenes, and the concentration of reservoir microorganisms was 2 × 10⁻⁶. 3 The copies / mL meet the well selection criteria, as shown in Table 21.

[0195] Table 21 Reservoir Microbial Analysis of Well F

[0196] Category of oil production functional microorganisms Pseudomonas and Alcaligenes Reservoir microbial concentration (copies / mL) 2 x 10 3 ]]

[0197] (2) Screening an activator system suitable for the growth of oil-producing microorganisms

[0198] To effectively activate microorganisms in the oil reservoir and enhance their oil recovery capabilities, single-factor optimization experiments were first conducted on the carbon, nitrogen, phosphorus, and growth factors in the activator system. The results of the single-factor optimization of the activator system, as shown in Tables 22 to 25, indicate that the optimal carbon, nitrogen, phosphorus, and growth factors are molasses, monosodium glutamate, sodium polyphosphate, and small molecule peptides, respectively.

[0199] Table 22 Single-factor experiments with different carbon sources in the activator system

[0200] Carbon source 5 g / L Microbial concentration copies / mL Sucrose 2.0 x 10 8 ]]> Glucose 1.3 x 10 8 <!-- 14 -->]]> Molasses 5.9 x 10 7 ]]

[0201] Table 23 Single-factor experiments with different nitrogen sources in the activator system.

[0202]

[0203]

[0204] Table 24 Single-factor experiments with different phosphorus sources in the activator system

[0205] Phosphorus source 1 g / L Microbial concentration copies / mL Sodium polyphosphate 2.8 x 10 8 ]] Ammonium dihydrogen phosphate 1.8 x 10 8 ]]> Diammonium hydrogen phosphate 2.2 x 10 8 ]]> Disodium hydrogen phosphate 2.5 x 10 8 ]]

[0206] Table 25 Single-factor experiments of different growth factors in the activator system

[0207] Growth factor 0.1 g / L Microbial concentration copies / mL Methionine 2.1 x 10 8 ]]> Yeast powder 2.2 x 10 8 ]]> Mannitol 1.4 x 10 8 ]]> Xylitol 2.0 x 10 8 ]]> p-Hydroxytoluene 2.6 x 10 8 ]]> Small molecule peptide 3.0 x 10 8 ]]

[0208] Then, the concentration of the activator system, mainly composed of sucrose, monosodium glutamate, sodium polyphosphate, and small molecule peptides, was further optimized to design L93. 4An orthogonal experiment was conducted using a 4-factor, 3-level model. The optimal activator system for effectively activating Pseudomonas and Alcaligenes in oil wells was determined, with the concentration of activated microorganisms and the proportion of oil-producing microorganisms as indicators. The results are shown in Table 26. System #7, with 20 g / L sucrose, 10 g / L monosodium glutamate, 5 g / L sodium polyphosphate, and 0.5 g / L small molecule peptides, was the optimal activator system, resulting in a microbial concentration of 3.6 × 10⁻⁶. 8 The population of oil-producing microorganisms, Pseudomonas and Alcaligenes, accounted for 60% of the total, giving them a dominant position in the microbial ecosystem.

[0209] Table 26 Statistical results of orthogonal optimization experiments for the activator system

[0210]

[0211]

[0212] (3) Indoor model oil displacement experiments were conducted using the activator system selected above.

[0213] As can be seen from the core displacement results in Table 27, the No. 7 optimal activator system with 0.3PV injection can activate reservoir microorganisms and increase crude oil recovery by 21.4%, demonstrating the potential for single-well huff and puff using reservoir endogenous microorganisms.

[0214] Table 27 Microbial enhanced oil recovery effect of oil well F

[0215]

[0216] (4) After the activator system screened in step (2) has activated the oil well's oil production functional microorganisms, the crude oil is subjected to full hydrocarbon gas chromatography analysis to obtain parameters reflecting the effective effect of the oil production microorganisms on the crude oil.

[0217] Crude oil from well F, after microbial activity, was subjected to full-hydrocarbon gas chromatography analysis. The gas chromatograms were used to screen and identify marker components reflecting the changes in crude oil composition following microbial activity: C9 and C2. 11 C 13 The sum of the peak areas of the three markers and the values ​​of C1 to C2 were used to determine their relative positions. 30 By comparing the sums of the chromatographic peak areas, the monitoring parameter characterizing the microbial swallowing and purging effect was obtained: C9+C 11 +C 13 / ∑C 30 The specific details of the chromatogram are as follows: Figure 4 As shown.

[0218] (5) Determine the relationship between the well shut-in time and the parameters reflecting the effective effect of oil production microorganisms on crude oil in oil wells;

[0219] First, the activator system is injected into oil well F through the annulus of the casing and sleeve. The injection volume is:

[0220] V = 3.14r 2 HФβ=3.14×10 2 ×18.0×0.32×0.8=1446.9m 3

[0221] Where r1 takes the value 10 and β1 takes the value 0.8.

[0222] Then, the well was shut in to allow the microorganisms in the reservoir to grow and multiply effectively, and to fully interact with the crude oil. After shutting in the well for different periods of 3, 5, 8, 10, 12, and 15 days, samples were taken for index monitoring. The specific monitoring results are shown in Table 28.

[0223] Table 28 Optimization Results of Monitoring the Shutdown Time of Oil Well F

[0224]

[0225] Based on the above-mentioned well-steaming time, microbial concentration, and C9+C 11 +C 13 / ∑C 30 The correlation characteristics among the characteristic chromatographic parameters of crude oil determined that the optimal shut-in time for microbial huff and puff in oil well F was 15 days, at which time the concentration of activated microorganisms was 1.2 × 10⁻⁶. 8 The number of copies / mL and the value of the characteristic chromatographic parameter are 25%, which meets the requirements for well opening time.

[0226] (6) Determine the relationship between production time and parameters reflecting the effective effect of oil-producing microorganisms on crude oil in oil wells;

[0227] Oil well F was shut down for 15 days before being reopened for normal production. Samples were taken at different times to compare daily oil and C9+C content. 11 +C 13 / ∑C 30 The crude oil's characteristic chromatographic parameters and other indicators were monitored to determine the optimal production time of the well, and the secondary microbial huff and puff measures were adjusted based on the monitoring results. The specific monitoring results are shown in Table 29.

[0228] Table 29 Optimization Results of Monitoring Production Time of Oil Well F

[0229]

[0230] The results above show that when oil well F is in normal production for 20 days, the daily oil production increase reaches 2.5t, C9+C 11 +C 13 / ∑C 30The values ​​of the characteristic chromatographic parameters of crude oil showed a sharp downward trend, decreasing from 26% to 5% in a short period of time.

[0231] (7) Adjust the oil well according to the well simmering time determined in step (5) and the production time determined in step (6), and then adjust the secondary microbial ingestion and expulsion according to the oil well monitoring results.

[0232] The results of dynamic monitoring of the oil well fall into the first category, indicating that the microbial injection system is not suitable for the actual application requirements in the field and the oil production increase effect is not significant. The injection system should be readjusted, and a suitable microbial injection system for this oil well should be obtained through subsequent research.

[0233] Example 4: Taking a certain oil well G in Shengli Oilfield as an example

[0234] A method for monitoring and regulating microbial huff and puff in a single well using crude oil chromatographic parameters includes the following steps:

[0235] (1) Screening oil wells:

[0236] The reservoir temperature of oil well G is 80℃, the crude oil viscosity is 960 mPa·s, the formation water salinity is 35600 mg / L, and the permeability is 1700 × 10⁻⁶. -3 μm 2 The effective thickness of the oil layer is 8.5 m, and the porosity is 0.35. Before the implementation of microbial single-well huff and puff, the oil production rate was 0.2 t / d, the liquid production rate was 20 t / d, and the water cut was 90%. Based on the population structure analysis of the oil well microorganisms, the types of oil-producing functional microorganisms were determined to be oleophilic bacilli, clostridium, anaerobic bacilli, and Bacillus. The reservoir microbial concentration was 500 copies / mL, which met the well selection conditions, as shown in Table 30.

[0237] Table 30 Reservoir Microbial Analysis in Well G

[0238] Category Oilibacter, Clostridium, anaerobic bacilli, Bacillus Reservoir microbial concentration (copies / mL) 500

[0239] (2) Screening an activator system suitable for the growth of oil-producing microorganisms

[0240] First, the concentrations of carbon source, nitrogen source, phosphorus source, and growth factor were fixed, and single-factor optimization experiments were conducted on these components.

[0241] The single-factor optimization results of the activator system in Tables 31 to 34 show that sucrose is the best carbon source compared to glucose and molasses.

[0242] Compared with monosodium glutamate, ammonium nitrate, ammonium chloride, soybean meal hydrolysate, corn flour hydrolysate and starch hydrolysate, sodium nitrate is the best nitrogen source;

[0243] Compared to sodium polyphosphate, ammonium dihydrogen phosphate, and disodium hydrogen phosphate, diammonium hydrogen phosphate is the best phosphorus source.

[0244] Compared to xylitol, yeast extract, mannitol, p-hydroxytoluene, and small molecule peptides, methionine is the best growth factor.

[0245] Table 31 Single-factor experiments with different carbon sources for the activator system.

[0246] Carbon source 5 g / L Microbial concentration copies / mL Sucrose 2.2 x 10 8 ]]> Glucose 1.3 x 10 8 ]]> Molasses 0.8 x 10 8 ]]

[0247] Table 32 Single-factor experiments with different nitrogen sources for the activator system.

[0248] Nitrogen source 10 g / L Microbial concentration copies / mL Sodium glutamate 1.8 x 10 8 ]]> Ammonium nitrate 1.9 x 10 8 ]]> Sodium nitrate 2.8 x 10 8 ]]> Ammonium chloride 2.0 x 10 8 ]]> Soybean hydrolysate 2.1 x 10 8 ]]> Corn powder hydrolysate 2.1 x 10 8 ]]> Starch hydrolysate 2.0 x 10 8 ]]>

[0249] Table 33 Single-factor experiments with different phosphorus sources for the activator system.

[0250] Phosphorus source 1 g / L Microbial concentration copies / mL Sodium polyphosphate 2.1 x 10 8 ]]> Ammonium dihydrogen phosphate 2.0 x 10 8 ]]> Diammonium hydrogen phosphate 2.6 x 10 8 ]]> Disodium hydrogen phosphate 2.2 x 10 8 ]]>

[0251] Table 34 Single-factor experiments with different growth factors in the activator system

[0252] Growth factor 0.1 g / L Microbial concentration copies / mL Methionine 3.3 x 10 8 ]]> Yeast powder 3.0 x 10 8 ]]> Mannitol 3.1 x 10 8 ]]> Xylitol 3.0 x 10 8 ]]> p-Hydroxytoluene 2.3 x 10 8 ]]> Small molecule peptide 2.6 x 10 8 ]]>

[0253] Then, the concentration of the components in the activator system, consisting of sucrose, sodium nitrate, diammonium hydrogen phosphate, and methionine, was further optimized to design L93. 4 An orthogonal experiment was conducted using a 4-factor, 3-level model. The optimal activator system for effectively activating oil-producing microorganisms (including *Bacillus oleophilus*, *Clostridium*, anaerobic bacteria, and *Bacillus*) in oil wells was determined, with the concentration of activated microorganisms and the proportion of oil-producing microorganisms as indicators. The results are shown in Table 35. System #6, with sucrose 10 g / L, sodium nitrate 50 g / L, diammonium hydrogen phosphate 1 g / L, and methionine 0.5 g / L, was the optimal activator system, resulting in a microbial concentration of 4.9 × 10⁻⁶. 8 The population of oil-producing microorganisms, including oleophilic bacilli, clostridium, anaerobic bacilli, and Bacillus, accounts for 60% of the total, giving them a dominant position in the microbial ecosystem.

[0254] Table 35 Statistical results of orthogonal optimization experiments for the activator system

[0255]

[0256]

[0257] (3) Using the activator system screened above, an indoor physical model oil displacement experiment was conducted, specifically including the following steps:

[0258] (31) The microbial concentration of the 6# activator system in step (22) is ≥10 8If copies / mL, proceed to step (32);

[0259] (32) The proportion of oil recovery functional microorganisms in the 6# activator system in step (22) is 60% or ≥55%, then proceed to step (34);

[0260] (34) Conduct physical simulation oil displacement experiments:

[0261] (341) Fill the rock core, vacuum saturate the formation water, and measure the porosity and permeability parameters;

[0262] (342) Saturate the oil and calculate the original oil saturation;

[0263] (343) One water drive to the core produced fluid with a water content of more than 95%;

[0264] (344) Inject 0.3PV 6# activator system and incubate statically at reservoir temperature for 10 days;

[0265] (345) Finally, perform a second water flooding to 100% water content and calculate the oil displacement effect; if the crude oil recovery rate increases by ≥15%, proceed to step (4); otherwise, end the operation.

[0266] As can be seen from the core displacement results in Table 36, the injection of 0.3PV of the No. 6 activator system can activate reservoir microorganisms and increase crude oil recovery by 15.5%, demonstrating the potential for single-well huff and puff using reservoir endogenous microorganisms.

[0267] Table 36 Microbial enhanced oil recovery effect of oil well A

[0268]

[0269] (4) After the activator system screened in step (2) has activated the oil well's oil production functional microorganisms, the crude oil is subjected to full hydrocarbon gas chromatography analysis to obtain parameters reflecting the effective effect of the oil production microorganisms on the crude oil.

[0270] Crude oil from well F, after microbial activity, underwent full-hydrocarbon gas chromatography analysis. The gas chromatograms were used to screen and identify marker components reflecting the changes in crude oil composition following microbial activity: C7 and C9. The sum of the peak areas of these two markers was compared with those of C1 to C9. 30 By comparing the sum of the chromatographic peak areas, the monitoring parameter characterizing the microbial swallowing and purging effect is obtained: C7 + C9 / ∑C 30 The specific details of the chromatogram are as follows: Figure 5 As shown.

[0271] (5) Determine the relationship between the well shut-in time and the parameters reflecting the effective effect of oil production microorganisms on crude oil in oil wells;

[0272] First, an activator system is injected into oil well G through the annulus of the casing and sleeve. The injection volume is:

[0273] V = 3.14r 2 HФβ=3.14×9 2 ×8.5×0.35×0.7=529.7m 3

[0274] Where: r1 takes the value 9, β1 takes the value 0.7;

[0275] Then, the well is shut in to allow the oil-producing microorganisms in the reservoir to grow and multiply effectively, and to fully interact with the crude oil. After shutting in the well for different periods of 5, 10, 15, 20, 25, and 30 days, samples are taken for index monitoring. The specific monitoring results are shown in Table 37.

[0276] Table 37 Monitoring and optimization results of well G shut-in time

[0277]

[0278]

[0279] Based on the above-mentioned well-closing time, microbial concentration, and C7+C9 / ∑C 30 The correlation characteristics among the characteristic chromatographic parameters of crude oil determined that the optimal shut-in time for microbial huff and puff in oil well G was 30 days, at which time the concentration of activated microorganisms was 6.0 × 10⁻⁶. 7 The number of copies / mL and the value of the characteristic chromatographic parameter were 28%, which met the requirements for well opening time.

[0280] (6) Determine the relationship between production time and parameters reflecting the effective effect of oil production microorganisms on crude oil in oil wells;

[0281] Oil well G was shut down for 30 days before being reopened for normal production. Samples were taken at different times to analyze daily oil and C7+C9 / ∑C. 30 The crude oil's characteristic chromatographic parameters and other indicators were monitored to determine the optimal production time of the well, and the secondary microbial huff and puff measures were adjusted based on the monitoring results. The specific monitoring results are shown in Table 38.

[0282] Table 38 Monitoring and optimization results of production time of oil well G

[0283]

[0284] The results above show that when oil well G is in normal production for 150 days, the daily oil production increase reaches 5.3t, C7+C9 / ∑C 30The characteristic chromatographic parameters of crude oil first rose to 35% and then decreased to 3%, indicating that the microbial injection system has a certain single-well huff and puff effect on oil well G.

[0285] (7) Adjust the oil well according to the well simmering time determined in step (5) and the production time determined in step (6), and then adjust the secondary microbial ingestion and expulsion according to the oil well monitoring results.

[0286] The changes in the oil well dynamic monitoring results fall into the second category. To further extend the effective period of single-well huff and puff, secondary microbial huff and puff adjustments are necessary. Subsequently, the effectiveness of secondary microbial huff and puff can be improved by increasing parameters such as well-drainage time or the injection volume of the microbial system to increase the number of microorganisms or expand the contact area between the microorganisms and crude oil.

[0287] Example 5: Taking a certain oil well H in Shengli Oilfield as an example

[0288] A method for monitoring and regulating microbial huff and puff in a single well using crude oil chromatographic parameters includes the following steps:

[0289] (1) Screening oil wells:

[0290] The reservoir temperature of oil well H is 38℃, the crude oil viscosity is 3600 mPa·s, the formation water salinity is 56100 mg / L, and the permeability is 360 × 10⁻⁶. -3 μm 2 The effective thickness of the oil layer is 12.0 m, and the porosity is 0.28. Before the implementation of microbial single-well huff and puff, the oil production rate was 1.5 t / d, the liquid production rate was 5 t / d, and the water cut was 70%. Based on the population structure analysis of the oil well microorganisms, the types of microorganisms for oil production were determined to be Pseudomonas, Rhodococcus, and Short Bacillus, with a reservoir microbial concentration of 680 copies / mL, which meets the well selection conditions, as shown in Table 39.

[0291] Table 39 Reservoir Microbial Analysis in Well H

[0292] Category of oil production functional microorganisms Pseudomonas, Rhodococcus and Brevibacterium Reservoir microbial concentration (copies / mL) 680

[0293] (2) Screening an activator system suitable for the growth of oil-producing microorganisms

[0294] First, with the concentrations of carbon source, nitrogen source, phosphorus source, and growth factor fixed, single-factor optimization experiments were conducted on these components:

[0295] The single-factor optimization results of the activator system from Tables 40 to 43 show that:

[0296] Compared to sucrose and molasses, glucose is the optimal carbon source, and the activated microbial concentration is 4.6 × 10⁻⁶. 8 copies / mL;

[0297] Compared with ammonium nitrate, sodium nitrate, ammonium chloride, soybean meal hydrolysate, corn flour hydrolysate, and starch hydrolysate, monosodium glutamate (MSG) is the optimal nitrogen source, with an activated microbial concentration of 5.0 × 10⁻⁶. 8 copies / mL;

[0298] Compared to sodium polyphosphate, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate, disodium hydrogen phosphate is the optimal phosphorus source, with an activated microbial concentration of 5.2 × 10⁻⁶. 8 copies / mL;

[0299] Compared to methionine, yeast extract, mannitol, p-hydroxytoluene, and small molecule peptides, xylitol is the optimal growth factor, with an activated microbial concentration of 5.5 × 10⁻⁶. 8 copies / mL.

[0300] Table 40 Single-factor experiments with different carbon sources for the activator system.

[0301] Carbon source 5 g / L Microbial concentration copies / mL Sucrose 2.3 x 10 8 ]]> Glucose 4.6 x 10 8 ]]> Molasses 2.9 x 10 8 ]]>

[0302] Table 41 Single-factor experiments with different nitrogen sources for the activator system

[0303] Nitrogen source 10 g / L Microbial concentration copies / mL Sodium glutamate 5.0 x 10 8 ]]> Ammonium nitrate 2.9 x 10 8 ]] Sodium nitrate 2.8 x 10 8 ]]> Ammonium chloride 0.6 x 10 8 ]]> Soybean hydrolysate 1.0 x 10 8 ]]> Corn powder hydrolysate 2.0 x 10 8 ]]> Starch hydrolysate 3.0 x 10 8 ]]>

[0304] Table 42 Single-factor experiments with different phosphorus sources for the activator system.

[0305] Phosphorus source 1 g / L Microbial concentration copies / mL Sodium polyphosphate 1.5 x 10 8 ]]> Ammonium dihydrogen phosphate 1.8 x 10 8 ]]> Diammonium hydrogen phosphate 2.2 x 10 8 ]]> Disodium hydrogen phosphate 5.2 x 10 8 ]]>

[0306] Table 43 Single-factor experiments with different growth factors in the activator system

[0307] Growth factor 0.1 g / L Microbial concentration copies / mL Methionine 5.1 x 10 8 ]] Yeast powder 4.6 x 10 8 ]]> Mannitol 5.0 x 10 8 ]]> Xylitol 5.5 x 10 8 ]]> p-Hydroxytoluene 4.5 x 10 8 ]]> Small molecule peptides 4.2 x 10 8 ]]>

[0308] Then, the concentration of the activator system, consisting of glucose, monosodium glutamate, disodium hydrogen phosphate, and xylitol, was further optimized to effectively activate Pseudomonas, Rhodococcus, and Short Bacillus bacteria in the oil well. The L93 design... 4 An orthogonal experiment was conducted using a 4-factor, 3-level model. The optimal activator system was determined by evaluating the concentration of activated microorganisms and the proportion of oil-producing functional microorganisms. The specific results are shown in Table 44. System #3, with glucose 5 g / L, monosodium glutamate 50 g / L, disodium hydrogen phosphate 5 g / L, and xylitol 1 g / L, was the optimal activator system, resulting in a microbial concentration of 5.9 × 10⁻⁶. 8 The population of oil-producing functional microorganisms, including Pseudomonas, Rhodococcus, and Short Bacillus, accounted for 40% of the total, indicating a lack of dominant population. Therefore, it is necessary to introduce exogenous oil-producing functional microbial fermentation broth to regulate and enhance their dominant position in the reservoir microbial ecosystem.

[0309] Table 44 Statistical results of orthogonal optimization experiments for the activator system

[0310]

[0311] Different concentrations of 3.6 × 10 8 A sample of oil recovery microbial fermentation broth at a concentration of 80 mL / L was introduced into the formation water sample of well H. After incubation for a period of time with the addition of activator #3, the optimal injection volume of the exogenous oil recovery microbial fermentation broth was determined by the proportion of oil recovery microorganisms. Table 45 shows that when the injection volume of the exogenous oil recovery microbial fermentation broth was 80 mL / L, the proportion of activated oil recovery microorganisms reached 56%, indicating that Pseudomonas, Rhodococcus, and Short Bacillus gradually transformed into dominant oil recovery microorganisms in the reservoir environment, which is beneficial for enhancing oil recovery capabilities.

[0312] Table 45 Optimization results of injection volume of microbial fermentation broth for oil recovery

[0313]

[0314] (3) Indoor model oil displacement experiments were conducted using the activator system selected above.

[0315] As can be seen from the core displacement results in Table 46, injecting the No. 3 activator system with 0.3PV and the external oil recovery functional microbial fermentation fluid with a concentration of 80mL / L can activate reservoir microorganisms and increase crude oil recovery by 13.0%, but it does not have the potential to use reservoir endogenous microorganisms for single-well huff and puff.

[0316] Table 46 Microbial oil recovery effect of oil well H

[0317]

[0318] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A method for monitoring and regulating microbial huff and puff in a single well using crude oil chromatographic parameters, characterized in that, Includes the following steps: (1) Screening oil wells; (2) Screening an activator system suitable for the growth of oil-producing microorganisms; (3) Conduct indoor physical model oil displacement tests to determine the oil displacement effect of activated oil-producing microorganisms; (4) Take the crude oil from the oil well after activation by the activator system screened in step (2) and perform full hydrocarbon gas chromatography analysis to obtain parameters reflecting the effective effect of oil production microorganisms on crude oil in the oil well. (5) Determine the relationship between the well shut-in time and the parameters reflecting the effective effect of oil production microorganisms on crude oil in the well; (6) Determine the relationship between production time and parameters reflecting the effective effect of oil-producing microorganisms on crude oil in oil wells; (7) Adjust the oil well according to the well-closing time determined in step (5) and the production time determined in step (6), and then adjust the secondary microbial huff and puff according to the oil well monitoring results, wherein: Step (4) involves full hydrocarbon gas chromatography analysis, which uses the full hydrocarbon gas chromatogram of crude oil to screen and identify five relatively high peak values ​​with a carbon number less than 20 that can reflect the changes in crude oil composition after the action of oil-producing microorganisms. These components have the characteristics of significant changes and easy identification. Finally, parameters that can characterize the effect of crude oil production in oil wells are determined. The parameter characterizing the effect of crude oil in oil wells refers to the five highest peaks (C50, less than 20 carbons) and the five highest peaks (C50, less than 20 carbons) of the marker components. a C b C c C d C e The sum of the areas and C1 to C 30 By comparing the sum of the total peak areas of the components, a parameter reflecting the effective effect of oil-producing microorganisms on crude oil from oil wells is obtained: C a +C b +C c +C d +C e / ∑C 30 ; The relationship between the well-sinking time mentioned in step (5) and the parameter reflecting the effective effect of oil-producing microorganisms on crude oil in the well refers to: The activator system selected in step (2) was injected into the oil well at the microbial huff and puff site, and the well was kept simmered to allow it to fully multiply for different periods of time. The simmering time, the number of microorganisms, and the parameter C reflecting the effective effect of the oil-producing microorganisms on the crude oil were continuously monitored. a +C b +C c +C d +C e / ∑C 30 Based on the correlation characteristics between them, the optimal well shut-in time is determined by optimizing the monitoring results. The well shut-in time index must simultaneously meet the following conditions: The concentration of activated microorganisms is ≥10. 7 copies / mL; C a +C b +C c +C d +C e / ∑C 30 ≥20%; The relationship between the production time mentioned in step (6) and the parameters reflecting the effective effect of oil-producing microorganisms on crude oil in oil wells refers to: After meeting the well-closing time requirements for microbial single-well huff and puff application in step (5) above, the well is opened for production. Then, on-site sampling was conducted to continuously monitor well production time, daily oil increase, and chromatographic parameter C. a +C b +C c +C d +C e / ∑C 30 The correlation characteristics between them; The optimal production time is determined based on monitoring results.

2. The method for monitoring and regulating microbial single-well huff and puff using crude oil chromatographic parameters as described in claim 1, characterized in that, The criteria for selecting oil wells in step (1) are: reservoir temperature < 100℃, permeability > 10×10⁻⁶. -3 μm 2 Formation water salinity < 80,000 mg / L, crude oil viscosity < 10,000 mPa·s, and possessing at least two types of oil recovery microorganisms with a concentration ≥ 10 2 The oil recovery microorganisms are one of the following: denitrifying bacteria, anaerobic bacteria, oleophilic bacteria, Bacillus, Pseudomonas, Alcaligenes, Rhodococcus, Short bacilli, Dist., and Clostridium.

3. The method for monitoring and regulating microbial single-well huff and puff using crude oil chromatographic parameters as described in claim 1, characterized in that, Step (2) includes the following steps: (21) Through single-factor experiments, using the concentration of activated microorganisms as an indicator, the components of the activation system that can effectively activate microorganisms in oil wells, including carbon source, nitrogen source, phosphorus source and growth factor, were determined. (22) Through L93 4 An orthogonal experiment was conducted using four factors and three levels. The concentration of activated microorganisms and the proportion of oil-producing functional microorganisms were used as indicators to optimize and determine the optimal activator system for effectively activating oil-producing functional microorganisms in oil wells. Among these factors: The activator system contains 5–20 g / L carbon source, 10–50 g / L nitrogen source, 1–5 g / L phosphorus source, and 0.1–1 g / L growth factor.

4. The method for monitoring and regulating microbial single-well huff and puff using crude oil chromatographic parameters as described in claim 3, characterized in that, In step (21), the carbon source is one of sucrose, glucose, or molasses.

5. The method for monitoring and regulating microbial single-well huff and puff using crude oil chromatographic parameters as described in claim 3, characterized in that, In step (21), the nitrogen source is one of the following: monosodium glutamate, ammonium nitrate, sodium nitrate, ammonium chloride, soybean meal hydrolysate, corn flour hydrolysate, or starch hydrolysate.

6. The method for monitoring and regulating microbial single-well huff and puff using crude oil chromatographic parameters as described in claim 3, characterized in that, In step (21), the phosphorus source is one of sodium polyphosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, or disodium hydrogen phosphate.

7. The method for monitoring and regulating microbial single-well huff and puff using crude oil chromatographic parameters as described in claim 3, characterized in that, The growth factors in step (21) are: one of the following: methionine, yeast extract, mannitol, xylitol, p-hydroxytoluene, and small molecule peptides.

8. The method for monitoring and regulating microbial single-well huff and puff using crude oil chromatographic parameters as described in claim 1, characterized in that, Step (3) includes the following steps: (31) Determine the microbial concentration of a set of tests for the optimal activator system finally determined in step (22). If the concentration of microorganisms is ≥10 8 If the number of copies / mL is less than 3, proceed to step (32); otherwise, end the operation. (32) Determine the proportion of oil recovery functional microorganisms in a set of tests of the best activator system finally determined in step (22). If it is ≥55%, proceed to step (34); otherwise, proceed to step (33). (33) Add the oil-producing functional microbial fermentation broth to the optimal activator system finally determined in step (22), and then reactivate the fermentation system in step (31). At this time, if the proportion of oil-producing functional microorganisms is ≥55%, proceed to step (35); otherwise, end the operation. Among them: the concentration of oil-producing microorganisms in the oil-producing microbial fermentation broth is 10. 8 ~10 9 copies / mL; The volume ratio of the oil recovery functional microbial fermentation broth to the optimal activator system finally determined in step (22) is (5-20):100; (34) Conduct physical simulation oil displacement experiments: (341) Fill the rock core, vacuum saturate the formation water, and measure the porosity and permeability parameters; (342) Saturate the oil and calculate the original oil saturation; (343) One water drive to the core produced fluid with a water content of more than 95%; (344) Inject 0.3PV of the activator system selected in step (2) and incubate at reservoir temperature for 10-15 days; (345) Finally, perform a second water flooding to 100% water content and calculate the oil displacement effect; if the crude oil recovery rate increases by ≥15%, proceed to step (4); otherwise, end the operation. (35) Conduct physical simulation oil displacement experiments: (351) Fill the rock core, vacuum saturate the formation water, and measure the porosity and permeability parameters; (352) Saturate the oil and calculate the original oil saturation; (353) One water drive to produce core fluid with a water content of over 95%; (354) Inject 0.3PV of the activator system selected in step (2) and the mixture of the fermentation broth of the oil-producing microorganisms, and let it stand at the reservoir temperature for 10 to 15 days. (345) Finally, perform a second water flooding to 100% water content and calculate the oil displacement effect; if the crude oil recovery rate increases by ≥15%, proceed to step (4); otherwise, end the operation.

9. The method for monitoring and regulating microbial single-well huff and puff using crude oil chromatographic parameters as described in claim 1, characterized in that, The injection volume V of the activator system selected in step (2) + oil recovery function microbial fermentation fluid in the oil well at the microbial huff and puff site is calculated according to the following formula: V=3.14r 2 HФβ Where: V—the amount of activator injected into the system, m 3 ; r—processing radius, m, with a value range of 8 to 10; H—Effect thickness of high-permeability oil layer, m; Ф—Porosity of the oil layer, dimensionless; β—Dosage coefficient, dimensionless, with a value range of 0.6 to 0.

8.

10. The method for monitoring and regulating microbial single-well huff and puff using crude oil chromatographic parameters as described in claim 1, characterized in that, In step (6), when the oil well monitoring indicators simultaneously meet the following conditions: peak daily oil production of a single well ≥ 3t, C a +C b +C c +C d +C e / ∑C 30 When the percentage is greater than 5%, maintain normal production of the oil well.

11. The method for monitoring and regulating microbial single-well huff and puff using crude oil chromatographic parameters as described in claim 8, characterized in that, There are three types of results from the dynamic monitoring of the oil wells in step (7): (a) Well opening time of the sluice-flow well ≤20 days, C a +C b +C c +C d +C e / ∑C 30 If the concentration is ≤5%, it indicates that the microbial injection system is not suitable for field application requirements, and a more suitable microbial injection system should be obtained after further research. (b) When 30d ≤ well opening production time of the churn well ≤ 180d, C a +C b +C c +C d +C e / ∑C 30 When the percentage is ≤5%, it indicates that the microbial injection system is suitable for field application requirements and has a certain microbial single-well huff and puff effect. However, the huff and puff effective period needs to be further extended. Next, we can further improve the single-well huff and puff oil-increasing effect of microorganisms by optimizing and increasing the well simmering time or the injection volume of the microbial system. (c) When the well-starting production time of the churn well is >180 days, C a +C b +C c +C d +C e / ∑C 30 When the percentage is ≤5%, it indicates that the microbial injection system is suitable for field application requirements, and the single-well throughput effect of microorganisms is significant. The original system injection process should be continued for the field application of secondary throughput of microorganisms.

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