A method of determining a microbial single well huff and puff activator injection amount

Abstract

The application discloses a method for determining the injection amount of microbial single-well huff and puff activator, which comprises the following steps: (1) screening of test oil wells; (2) determination of test models; (3) determination of the relationship between biological field and activator theoretical treatment radius under single extreme difference condition; (4) determination of the relationship between biological field and activator theoretical treatment radius under different extreme difference conditions; and (5) determination of the injection amount of microbial huff and puff activator. The application has the following beneficial effects: (1) the method is simple, targeted, operable and accurate; (2) the injection amount of activator is saved by more than 30%, waste is avoided, and cost is reduced; (3) the on-site oil increasing effect is good, the effective period is more than 5 years, and the average daily oil increasing amount of single well is more than 5.0t; and (4) the application provides a scientific theoretical basis for determining or designing the injection amount of activator in the field test of microbial single-well huff and puff.

Description

Technical Field

[0001] This invention belongs to the field of microbial enhanced oil recovery technology, specifically relating to a method for determining the injection volume of microbial single-well huff and puff activator. Background Technology

[0002] Microbial single-well huff and puff refers to injecting a screened activator into a production well (oil well). The injected activator activates the microorganisms in the reservoir, and the microorganisms and their metabolites are used to treat the near-wellbore zone and wellbore, thereby improving the physical properties of crude oil, reducing crude oil flow resistance, and increasing oil well production.

[0003] Microbial single-well huff and puff has the advantages of low surface investment, simple operation, and quick results. In particular, it can improve the physical properties of crude oil, reduce crude oil flow resistance, and improve the efficiency of crude oil production in the wellbore and near-wellbore area.

[0004] Chinese invention patent application number 201510455322X, entitled "A Method for Improving the Huff and Puff Effect of Microorganisms in a Single Well," discloses a method for improving the huff and puff effect of microorganisms in a single well, comprising the following steps: (1) selection of a test well; (2) determination of the oxygen requirement of functional microorganisms; (3) on-site injection of functional microorganisms, activators, and oxygen; (4) on-site injection of subsequent air; (5) shutting in the test well; and (6) opening the test well for production. In the above patent, the determination of the on-site injection amount of microorganisms or activators for single-well huff and puff is based on the empirical formula "V=3.14R". 2 "HФβ", where β is the dosage coefficient, which is usually less than 1.0 (the specific value is related to the oil saturation).

[0005] However, the above method of determining the amount of activator injection has the following two problems: (1) R in the formula is the theoretical treatment radius of the activator, but the biofield sweep radius in microbial huff and puff is the key parameter that determines the huff and puff effect. Indoor studies have confirmed that microorganisms in the porous media of the reservoir have the characteristic of actively migrating to the oil-water interface. The biofield sweep radius is larger than the theoretical treatment radius of the activator. When the formula only considers the theoretical treatment radius of the activator, the amount of activator calculated is larger than the actual amount required, resulting in waste of activator and increased cost; (2) The reservoir generally has heterogeneity. Heterogeneity affects the sweep radius of the biofield and thus affects the implementation effect of microbial huff and puff. The formula lacks the reservoir heterogeneity correction factor, resulting in low accuracy of the activator amount calculated by the above formula. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, this invention provides a method for determining the injection amount of microbial single-well huff and puff activator. This method is simple, highly operable, and highly accurate. At the same time, it greatly reduces the amount of activator injected in the field, saving more than 30%, effectively avoiding waste of activator and reducing investment costs. This method provides a scientific theoretical basis for determining or designing the injection amount of activator in field tests of microbial single-well huff and puff.

[0007] Technical solution: A method for determining the injection volume of microbial single-well huff and puff activator, comprising the following steps: (1) Screening of test oil wells; (2) Determination of the experimental model; (3) Determination of the relationship between the biofield and the theoretical treatment radius of the activator under a single range condition; (4) Determination of the relationship between the biofield and the theoretical treatment radius of the activator under different range conditions; (5) Determination of the amount of microbial phagocytosis activator injected.

[0008] Furthermore, the screening criteria for the test oil wells in step (1) are: reservoir pressure less than 15 MPa, reservoir temperature less than 90℃, and total bacterial concentration in the reservoir greater than 1.0 × 10⁻⁶. 2 The oil volume / ml is less than 5000 mPa·s, and the well spacing between oil and water wells is greater than 50 m.

[0009] Furthermore, step (2) includes the following steps: (2a) Determining the dimensions of the three-dimensional model body; (2b) Determination of the proportion of quartz sand; (2c) Simulated core filling; Furthermore, the standard dimensions of the three-dimensional model body in step (2a) are as follows: 500mm≤length≤1000mm, 500mm≤width≤1000mm, and 50mm≤height≤100mm.

[0010] Furthermore, the number of sampling points of the three-dimensional object model body is greater than 30.

[0011] Furthermore, the quartz sand proportioning in step (2b) includes a quartz sand proportioning for the low-permeability zone and a quartz sand proportioning for the high-permeability zone, wherein: The standard for the proportion of quartz sand in the low-permeability zone is as follows: 30-40 mesh 8-9wt%; 40-60 mesh 10-15wt%; 80-100 mesh 20-25wt%; 100-150 mesh 12-15wt%; 200-300 mesh 6-8wt%; The balance is 60-80 mesh; The standard for the proportioning of quartz sand in the high-permeability zone is as follows: 30-40 mesh 1-5wt%; 40-60 mesh 10-15wt%; 80-100 mesh 35-40wt%; 100-150 mesh 5-10wt%; 200-300 mesh 1-3wt%; The remaining weight is 60-80 mesh.

[0012] Furthermore, step (2c) includes the following steps: Using the quartz sand gradation ratio determined in step (2b), five sets of simulated cores with ranges of 2, 4, 6, 8, and 10 were respectively filled, where: The permeability in the low-permeability zone is 450×10 -3 μm 2 ~550×10 -3 μm 2 ; The permeability in the high-permeability zone is 950×10 -3 μm 2 ~1050×10 -3 μm 2 1950×10 -3 μm 2 ~2050×10 -3 μm 2 2900×10 -3 μm 2 ~3100×10 -3 μm 2 3900×10 -3 μm 2 ~4100×10 -3 μm 2 4900×10 -3 μm 2 ~5100×10 -3 μm 2 .

[0013] Furthermore, the specific steps of step (3) are as follows: (31) Simulate core vacuum until the simulated core vacuum level is below -0.09 MPa; (32) Saturate the formation water in the test well. The saturation rate of the formation water is 3-5 ml / min. Calculate the pore volume of the simulated core. (33) The crude oil in the saturation test well was saturated at a rate of 3-5 ml / min; (34) Use the five-point well pattern for one water drive, with a water drive rate of 2-3 ml / min, and continue water drive until the water content of the oil well produced is greater than 90%. (35) Inject 0.1-0.15 PV activator solution into the simulated oil well at a rate of 3-5 ml / min, and calculate the theoretical treatment radius r1 of the activator; (36) Well closed and cultured for 15-30 days; (37) Sampling is performed at each sampling point of the three-dimensional physical model body, and the bacterial concentration in the sample at each sampling point is analyzed and obtained; (38) Draw the field map of the simulated core microbial concentration field, and determine the average treatment radius r2 of the biofield based on the field map of the microbial concentration field; (39) Determine the quantitative relationship between the treatment radius of the biofield and the theoretical treatment radius of the activator under a single range condition.

[0014] Furthermore, the specific method for determining the average treatment radius r2 of the biofield based on the field map of the bacterial concentration field in step (38) is as follows: (381) Using the field diagram of the bacterial concentration field, the threshold for effective bacterial concentration is set to 1.0 × 10⁻⁶. 7 The bacterial concentration is determined by the number of cells / ml, which defines the effective bacterial concentration boundary. (382) Calculate the area occupied by the boundary of the effective bacterial concentration based on the boundary of the effective bacterial concentration; (383) Based on the formula for the area of ​​a circle, the average treatment radius r2 of the biofield is calculated by the area occupied by the effective bacterial concentration.

[0015] Furthermore, step (4) includes the following steps: Based on the quantitative relationship between the biofield treatment radius and the theoretical treatment radius of the activator under the single range condition determined in step (3), a plot of the relationship is drawn with the range k on the horizontal axis and r2 / r1 on the vertical axis. A curve showing the relationship between r2 / r1 and k is then fitted, where: r2 / r1= The correlation coefficient of the fitted curve is greater than 0.995.

[0016] Furthermore, the amount of microbial phagocytosis activator injected in step (5) is determined according to the following formula: ,in: in: —Activator injection volume, m 3 ; — Biofield treatment radius, m; — Oil layer thickness of the test well, in meters (m). — The porosity of the oil reservoir in the test well, as a decimal; —r2 / r1 relational function.

[0017] Beneficial Effects: The method for determining the injection volume of microbial single-well huff and puff activator disclosed in this invention has the following beneficial effects: (1) The method is simple and has the characteristics of being highly targeted, highly operable and highly accurate; (2) The amount of activator injected using this method is lower than that determined by conventional methods, saving more than 30% of the amount of activator injected, effectively avoiding waste of activator and reducing investment costs; (3) It not only effectively saves the amount of activator injected, but also has a good on-site oil increase effect, with an effective period of more than 5 years and an average daily oil increase of more than 5.0t per well; (4) This invention provides a scientific theoretical basis for determining or designing the amount of activator injected in field tests of microbial single-well huff and puff. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the sampling point distribution of the three-dimensional object model body in Example 1; Figure 2 In Example 1 A schematic diagram of the relationship curve as k changes; Figure 3 In Example 2 A schematic diagram of the relationship curve as k changes; Figure 4 In Example 3 A schematic diagram of the relationship curve as k changes.

[0019] Figure 5 This is a flowchart of a method for determining the injection amount of microbial single-well huff and puff activator disclosed in this invention. Detailed Implementation

[0020] The specific embodiments of the present invention are described in detail below.

[0021] Example 1 Well A in a certain block of Shengli Oilfield 12 The oil well has a reservoir pressure of 12.5 MPa, a temperature of 78℃, a crude oil viscosity of 985 mPa·s, a well spacing of 100 m between oil and water wells, and a total bacterial concentration in the formation water of 1.1 × 10⁻⁶. 2The sample size is [number] cells / ml, the oil layer thickness is 8.5m, the porosity is 0.325, and the range is 2.5. The method of this invention is used to calculate the field injection volume of the microbial single-well huff-and-puff activator. The specific steps are as follows: (1) Screening of test oil wells Test well A 12 The reservoir pressure is 12.5 MPa, the temperature is 78℃, the crude oil viscosity is 985 mPa·s, the well spacing between oil and water is 100 m, and the total bacterial concentration in the formation water is 1.1 × 10⁻⁶. 2 The number of cells / ml meets the screening requirements of this invention.

[0022] (2) Determination of the experimental model; (2a) Determination of the dimensions of the three-dimensional model body The model's dimensions are: length 500mm, width 500mm, height 50mm. The model has 36 sampling points. (2b) Determination of the proportion of quartz sand The specific proportions of quartz sand for low-permeability areas are as follows: 30-40 mesh 8.2wt%, 40-60 mesh 12.5wt%, 60-80 mesh 35.2wt%, 80-100 mesh 22.3wt%, 100-150 mesh 14.5wt%, and 200-300 mesh 7.3wt%.

[0023] The specific proportions of quartz sand in the high-permeability zone are as follows: 30-40 mesh 2.5wt%, 40-60 mesh 12.2wt%, 60-80 mesh 40.5wt%, 80-100 mesh 37.3wt%, 100-150 mesh 6.3wt%, and 200-300 mesh 1.2wt%.

[0024] (2c) Simulated core loading Using the quartz sand mix determined in step (2b), five simulated core samples with permeability ranges of 2, 4, 6, 8, and 10 were filled, namely Y1, Y2, Y3, Y4, and Y5, respectively. The permeability of the low-permeability zone was 500 × 10⁻⁶ for each sample. -3 μm 2 The permeability in the high-permeability zone is 1000×10 -3 μm 2 2000×10 -3 μm 2 3000×10 -3 μm 2 4000×10 -3 μm 2 5000×10 -3 μm 2 .

[0025] (3) Determination of the relationship between the biofield and the theoretical treatment radius of the activator under a single range condition The determination method described herein comprises the following specific steps: The above five sets of simulated cores (Y1, Y2, Y3, Y4, Y5) were evacuated until the vacuum level of the simulated cores reached -0.09 MPa; Saturation test well A 12 The formation water was saturated at a rate of 3 ml / min. The pore volume PV of the simulated core was calculated to be 3.82 L, 3.95 L, 4.12 L, 4.25 L, and 4.37 L, respectively. The crude oil in the saturation test well was saturated at a rate of 3 ml / min. A five-point well pattern was used for one water drive at a rate of 2 ml / min until the water content of the well produced fluid reached 90%. The test oil wells were injected with 0.1PV activator solution at injection rates of 0.382L, 0.395L, 0.412L, 0.425L, and 0.437L, respectively, at a rate of 3ml / min. The theoretical treatment radius r1 of the activator was calculated to be 8.1, 7.9, 8.2, 8.0, and 7.8cm, respectively. After the activator injection is completed, the well is shut in and incubated for 15 days. After the well shut-in period ends, samples are taken from each sampling point on the model.

[0026] Figure 1 The distribution maps of the model sampling points and the bacterial concentrations in the samples from each sampling point of the simulated core are shown in Tables 1, 2, 3, 4, and 5, respectively. Field maps of the simulated core bacterial concentration field were plotted using Surfer software. Based on the field maps of the bacterial concentration field, the average treatment radius r2 of the biofield was determined to be 17.0, 13.4, 11.5, 9.6, and 8.6 cm, respectively. The quantitative relationship between the treatment radius of the biofield and the theoretical treatment radius of the activator under a single range condition was determined to be r2 = 2.1r1, r2 = 1.7r1, r2 = 1.4r1, r2 = 1.2r1, and r2 = 1.1r1, respectively.

[0027] Table 1. Bacterial concentration test results at various sampling points of simulated core Y1, bacteria / ml Table 2. Bacterial concentration test results at various sampling points of simulated core Y2, bacteria / ml Table 3. Bacterial concentration test results at various sampling points of simulated core Y3, bacteria / ml Table 4. Bacterial concentration test results at various sampling points of simulated core Y4, bacteria / ml Table 5. Bacterial concentration test results at each sampling point of simulated core Y5, bacteria / ml (4) Determination of the relationship between the biofield and the theoretical treatment radius of the activator under different range conditions Based on the quantitative relationship between the biofield treatment radius and the theoretical treatment radius of the activator under the single range condition determined in step (3), when k=2, r2= 2.1r1; when k=4, r2= 1.7r1; when k=6, r2= 1.4r1; when k=8, r2= 1.2r1; and when k=10, r2= 1.1r1. Plot the x-axis as the range k and the y-axis as r2 / r1, and fit the curve showing the relationship between r2 / r1 and k. See [link to relevant documentation]. Figure 2 r2 / r1 = =0.05k 2 -0.55k+2.6, the correlation coefficient R of the fitted curve 2 =1.0.

[0028] (5) Determination of the amount of microbial phagocytosis activator injected =3.1416 × 5.2 2 ×8.5×0.325 / (0.05×2.5 2 -0.55×2.5+2.6) =234.67 / (0.3125-1.375+2.6) =234.67 / 1.54 =152.4m 3 Where: V1—Amount of activator injected, m 3 ; R— The treatment radius of the biofield is 2m. h— Oil layer thickness of the test well, in meters (m). — The porosity of the oil reservoir in the test well is dimensionless. —r2 / r1 relational function.

[0029] The activator injection volume determined by the method of this invention was used to conduct a field test of microbial single-well huff and puff. The activator formulation was 5.0 g / L glucose, 2.5 g / L peptone, and 0.3 g / L dipotassium hydrogen phosphate. The field test results showed that the oil well was effective for 6.5 years, with an average daily oil increase of 5.8 t per well. At the same time, compared with the existing technology, the activator injection volume was reduced by 32.2%, and the field test results were good.

[0030] Example 2 Well C in a certain block of Shengli Oilfield 15 The oil well has a reservoir pressure of 10.2 MPa, a temperature of 72℃, a crude oil viscosity of 1256 mPa·s, a well spacing of 150 m between oil and water wells, and a total bacterial concentration in the formation water of 2.0 × 10⁻⁶. 2 The sample size is [number] cells / ml, the oil layer thickness is 5.0 m, the porosity is 0.312, and the range is 3.0. The method of this invention is used to calculate the field injection volume of the microbial single-well huff-and-puff activator. The specific steps are as follows: (1) Screening of test oil wells Test oil well C 15 The reservoir pressure is 10.2 MPa, the temperature is 72℃, and the crude oil viscosity is 1256. mPa·s, oil and water well spacing 150m, formation water total bacteria concentration 2.0×10 2 The number of cells / ml meets the screening requirements of this invention.

[0031] (2) Determination of the experimental model; (2a) Determination of the dimensions of the three-dimensional model body The model's dimensions are: length 800mm, width 800mm, and height 60mm. The model has 36 sampling points. (2c) Determination of the proportion of quartz sand The specific proportions of quartz sand for low-permeability areas are as follows: 30-40 mesh 8.0wt%, 40-60 mesh 10.0wt%, 60-80 mesh 39.0wt%, 80-100 mesh 20.0wt%, 100-150 mesh 15.0wt%, and 200-300 mesh 8wt%.

[0032] The specific proportions of quartz sand in the high-permeability zone are as follows: 30-40 mesh 1.0wt%, 40-60 mesh 10.0wt%, 60-80 mesh 48wt%, 80-100 mesh 35.0wt%, 100-150 mesh 5.0wt%, and 200-300 mesh 1.0wt%.

[0033] (2c) Simulated core loading Using the quartz sand mix determined in step (2b), five simulated core samples with permeability ranges of 2, 4, 6, 8, and 10 were filled, namely X1, X2, X3, X4, and X5, respectively. The permeability of the low-permeability zone was 450 × 10⁻⁶ for all samples. -3 μm 2 The permeability in the high-permeability zone is 950×10 -3 μm 2 1950×10 -3 μm 2 2900×10 -3 μm2 3900×10 -3 μm 2 4900×10 -3 μm 2 .

[0034] (3) Determination of the relationship between the biofield and the theoretical treatment radius of the activator under a single range condition The determination method described herein comprises the following specific steps: The above five sets of simulated cores (X1, X2, X3, X4, X5) were evacuated until the vacuum level of the simulated cores was -0.09 MPa; Saturation test oil well C 15 The formation water was saturated at a rate of 5 ml / min. The pore volume PV of the simulated core was calculated to be 11.8 L, 12.1 L, 12.6 L, 13.2 L, and 13.5 L, respectively. The crude oil in the saturation test well was saturated at a rate of 5 ml / min. A five-point well pattern was used for one water drive, with a water drive rate of 3 ml / min, until the water content of the oil well produced fluid reached 90%. The test oil wells were injected with 0.15PV activator solution at concentrations of 1.77L, 1.85L, 1.89L, 1.98L, and 2.02L, respectively, at an injection rate of 5ml / min. The theoretical treatment radius r1 of the activator was calculated to be 16.8 cm, 17.2 cm, 17.4 cm, 17.8 cm, and 18.0 cm, respectively. After the activator injection is completed, the well is shut in and incubated for 30 days. After the well shut-in period, samples were taken from each sampling point of the model to simulate the bacterial concentration in the samples from each sampling point of the core, as shown in Tables 6, 7, 8, 9, and 10. The field map of the simulated core bacterial concentration field was plotted using Surfer software. Based on the field map of the bacterial concentration field, the average treatment radius r2 of the biofield was determined to be 43.7, 36.1, 29.6, 24.9, and 21.6 cm, respectively. The quantitative relationship between the treatment radius of the biofield and the theoretical treatment radius of the activator under a single range condition was determined to be r2 = 2.6r1, r2 = 2.1r1, r2 = 1.7r1, r2 = 1.4r1, and r2 = 1.2r1, respectively.

[0035] Table 6. Bacterial concentration test results at each sampling point of simulated core X1, bacteria / ml Table 7. Bacterial concentration test results at each sampling point of simulated core X2, bacteria / ml Table 8. Bacterial concentration test results at each sampling point of simulated core X3, bacteria / ml Table 9. Bacterial concentration test results at each sampling point of simulated core X4, bacteria / ml Table 10. Bacterial concentration test results at each sampling point of simulated core X5, bacteria / ml (4) Determination of the relationship between the biofield and the theoretical treatment radius of the activator under different range conditions Based on the quantitative relationship between the biofield treatment radius and the theoretical treatment radius of the activator under the single range condition determined in step (3), when k=2, r2= 2.6r1; when k=4, r2= 2.1r1; when k=6, r2= 1.7r1; when k=8, r2= 1.4r1; and when k=10, r2= 1.2r1. Plot the x-axis as the range k and the y-axis as r2 / r1, and fit the curve showing the relationship between r2 / r1 and k. See [link to relevant documentation]. Figure 3 r2 / r1 = ω(k) = 0.05k 2 -0.65k+3.2, the correlation coefficient R of the fitted curve 2 =1.0.

[0036] (5) Determination of the amount of microbial phagocytosis activator injected =3.1416 × 8.0 2 ×5.0×0.312 / (0.05×3.0 2 -0.65×3.0+3.2) =313.66 / (0.45-1.95+3.2) =234.67 / 1.7 =138.0m 3 Where: V1—Amount of activator injected, m 3 ; R— Biofield treatment radius, m; h— The thickness of the oil layer in the test well, in meters (m). — The porosity of the oil reservoir in the test well is dimensionless. —r2 / r1 relational function.

[0037] The activator injection volume determined using the method of this invention is 138.0 mg / L. 3A field test of microbial single-well huff and puff was conducted. The activator formula was 4.5 g / L starch, 3.2 g / L sodium nitrate, and 0.25 g / L dipotassium hydrogen phosphate. The field test results showed that the oil well was effective for 7.2 years, with an average daily oil increase of 6.3 tons per well. Compared with existing technologies, the activator injection volume was reduced by 45.3%, and the field test results were good.

[0038] Example 3 Well E in a certain block of Shengli Oilfield 31 The oil well has a reservoir pressure of 11.5 MPa, a temperature of 75℃, a crude oil viscosity of 1856 mPa·s, a well spacing of 180 m between oil and water wells, and a total bacterial concentration in the formation water of 5.0 × 10⁻⁶. 3 The sample size is [number] cells / ml, the oil layer thickness is 7.5m, the porosity is 0.305, and the range is 2.3. The method of this invention is used to calculate the field injection volume of the microbial single-well huff-and-puff activator. The specific steps are as follows: (1) Screening of test oil wells Test well E 31 The reservoir pressure is 11.5 MPa, the temperature is 75℃, and the crude oil viscosity is 1856. mPa·s, oil and water well spacing 180m, formation water total bacteria concentration 5.0×10 5 The number of cells / ml meets the screening requirements of this invention.

[0039] (2) Determination of the experimental model; (2a) Determination of the dimensions of the three-dimensional model body The model body has the following dimensions: length 1000mm, width 1000mm, height 100mm, and sampling points 30.

[0040] (2b) Determination of the proportion of quartz sand The specific proportions of quartz sand for low-permeability zones are as follows: 30-40 mesh 9.0wt%, 40-60 mesh 15wt%, 60-80 mesh 33.0wt%, 80-100 mesh 25.0wt%, 100-150 mesh 12.0wt%, and 200-300 mesh 6.0wt%.

[0041] The specific proportions of quartz sand in the high-permeability zone are as follows: 30-40 mesh 5.0wt%, 40-60 mesh 15.0wt%, 60-80 mesh 27.0wt%, 80-100 mesh 40.0wt%, 100-150 mesh 10.0wt%, and 200-300 mesh 3.0wt%.

[0042] (2c) Simulated core loading Using the quartz sand mix determined in step (2b), five simulated core samples with permeability ranges of 2, 4, 6, 8, and 10 were filled, namely Z1, Z2, Z3, Z4, and Z5, respectively. The permeability of the low-permeability zone was 550 × 10⁻⁶ for all samples. -3 μm 2 The permeability in the high-permeability zone is 1050×10 -3 μm 2 2050×10 -3 μm 2 3100×10 -3 μm 2 4100×10 -3 μm 2 5100×10 -3 μm 2 .

[0043] (3) Determination of the relationship between the biofield and the theoretical treatment radius of the activator under a single range condition The determination method described herein comprises the following specific steps: The above five sets of simulated cores (Z1, Z2, Z3, Z4, Z5) were evacuated until the vacuum level of the simulated cores reached -0.09 MPa; Saturation test well E 31 The formation water was saturated at a rate of 4 ml / min. The pore volume PV of the simulated core was calculated to be 32.5 L, 33.5 L, 34.2 L, 35.0 L, and 36.8 L, respectively. The crude oil in the saturation test well was saturated at a rate of 4 ml / min. A five-point well pattern was used for one water drive, with a water drive rate of 2.5 ml / min, until the water content of the oil well produced fluid reached 90%. The test oil wells were injected with 0.10PV activator solution at concentrations of 3.25L, 3.35L, 3.42L, 3.50L, and 3.68L, respectively, at an injection rate of 4ml / min. The theoretical treatment radius r1 of the activator was calculated to be 10.2 cm, 10.3 cm, 10.4 cm, 10.7 cm, and 10.8 cm, respectively. After the activator injection is completed, the well is shut in and incubated for 20 days. After the well shut-in period, samples were taken from each sampling point of the model to simulate the bacterial concentration in the samples from each sampling point of the core. A field map of the simulated core bacterial concentration field was plotted. Based on the field map of the bacterial concentration field, the average treatment radius r2 of the biofield was determined to be 24.48, 20.6, 15.6, 12.84, and 11.88 cm, respectively. The quantitative relationship between the treatment radius of the biofield and the theoretical treatment radius of the activator under a single range condition was determined to be r2 = 2.4r1, r2 = 2.0r1, r2 = 1.5r1, r2 = 1.2r1, and r2 = 1.1r1, respectively.

[0044] (4) Determination of the relationship between the biofield and the theoretical treatment radius of the activator under different range conditions Based on the quantitative relationship between the biofield treatment radius and the theoretical treatment radius of the activator under the single range condition determined in step (3), when k=2, r2= 2.4r1; when k=4, r2= 2.0r1; when k=6, r2= 1.5r1; when k=8, r2= 1.2r1; and when k=10, r2= 1.1r1. Plot the x-axis as the range k and the y-axis as r2 / r1, and fit the curve showing the relationship between r2 / r1 and k. See [link to relevant documentation]. Figure 4 r2 / r1 = ω(k) = 0.0014k 2 -0.341k+3.06, the correlation coefficient R of the fitted curve 2 =0.991.

[0045] (5) Determination of the amount of microbial phagocytosis activator injected =3.1416 × 9.0 2 ×7.5×0.305 / (0.00143×2.3 2 -0.3414×2.3+3.06) =582.10 / (0.0075647-0.78522+3.06) =582.10 / 2.28 =255.3m 3 Where: V1—Amount of activator injected, m 3 ; R— Biofield treatment radius, m; h— The thickness of the oil layer in the test well, in meters (m). — The porosity of the oil reservoir in the test well is dimensionless. —r2 / r1 relational function.

[0046] The activator injection amount determined using the method of this invention is 255.3 mg / L. 3 A field test of microbial single-well huff and puff was conducted. The activator formula was 4.2 g / L starch, 3.0 g / L sodium nitrate, and 0.22 g / L dipotassium hydrogen phosphate. The field test results showed that the oil well was effective for 7.5 years, with an average daily oil increase of 7.0 t per well. Compared with existing technologies, the activator injection volume was reduced by 42.2%, and the field test results were good.

[0047] 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 determining the injection volume of a microbial single-well huff and puff activator, characterized in that, Includes the following steps: (1) Screening of test oil wells; (2) Determination of the experimental model; (3) Determination of the relationship between the biofield and the theoretical treatment radius of the activator under a single range condition; (4) Determination of the relationship between the biofield and the theoretical treatment radius of the activator under different range conditions; Based on the quantitative relationship between the biofield treatment radius and the theoretical treatment radius of the activator under the single range condition determined in step (3), a plot of the relationship is drawn with the range k on the horizontal axis and r2 / r1 on the vertical axis. A curve showing the relationship between r2 / r1 and k is then fitted, where: r2 / r1= The correlation coefficient of the fitted curve is greater than 0.995; (5) Determination of the injection amount of microbial phagocytosis activator, wherein: the injection amount of microbial phagocytosis activator is determined according to the following formula: ,in: in: —Activator injection volume, m 3 ; — Biofield treatment radius, m; — Oil layer thickness of the test well, in meters (m). — The porosity of the oil reservoir in the test well, as a decimal; —r2 / r1 relational function, where: Step (2) includes the following steps: (2a) Determining the dimensions of the three-dimensional model body; (2b) Determination of the proportion of quartz sand; (2c) Simulated core filling; The specific steps of step (3) are as follows: (31) Simulate core vacuum until the simulated core vacuum level is below -0.09 MPa; (32) Saturate the formation water in the test well. The saturation rate of the formation water is 3-5 ml / min. Calculate the pore volume of the simulated core. (33) The crude oil in the saturation test well was saturated at a rate of 3-5 ml / min; (34) Use the five-point well pattern for one water drive, with a water drive rate of 2-3 ml / min, and continue water drive until the water content of the oil well produced is greater than 90%. (35) Inject 0.1-0.15 PV activator solution into the simulated oil well at a rate of 3-5 ml / min, and calculate the theoretical treatment radius r1 of the activator; (36) Well closed and cultured for 15-30 days; (37) Sampling is performed at each sampling point of the three-dimensional physical model body, and the bacterial concentration in the sample at each sampling point is analyzed and obtained; (38) Draw the field map of the simulated core microbial concentration field, and determine the average treatment radius r2 of the biofield based on the field map of the microbial concentration field; (39) Determine the quantitative relationship between the treatment radius of the biofield and the theoretical treatment radius of the activator under a single range condition; The specific method for determining the average treatment radius r2 of the biofield based on the field map of the bacterial concentration field in step (38) is as follows: (381) Using the field diagram of the bacterial concentration field, the threshold for effective bacterial concentration is set to 1.0 × 10⁻⁶. 7 The bacterial concentration is determined by the number of cells / ml, which defines the effective bacterial concentration boundary. (382) Calculate the area occupied by the boundary of the effective bacterial concentration based on the boundary of the effective bacterial concentration; (383) Based on the formula for the area of ​​a circle, the average treatment radius r2 of the biofield is calculated by the area occupied by the effective bacterial concentration.

2. The method for determining the injection volume of a microbial single-well huff and puff activator according to claim 1, characterized in that, The screening criteria for the test wells in step (1) are: reservoir pressure less than 15 MPa, reservoir temperature less than 90℃, and total bacterial concentration greater than 1.0 × 10⁻⁶. 2 The oil volume / ml is less than 5000 mPa·s, and the well spacing between oil and water wells is greater than 50 m.

3. The method for determining the injection volume of a microbial single-well huff and puff activator according to claim 1, characterized in that, The standard dimensions of the three-dimensional model body in step (2a) are as follows: 500mm≤length≤1000mm, 500mm≤width≤1000mm, and 50mm≤height≤100mm.

4. The method for determining the injection volume of a microbial single-well huff and puff activator according to claim 2, characterized in that, The number of sampling points of the three-dimensional object model body is greater than 30.

5. The method for determining the injection volume of a microbial single-well huff and puff activator according to claim 2, characterized in that, The quartz sand mix proportions in step (2b) include the quartz sand mix proportions for the low-permeability zone and the quartz sand mix proportions for the high-permeability zone, wherein: The standard for the proportion of quartz sand in the low-permeability zone is as follows: 30-40 mesh 8-9wt%; 40-60 mesh 10-15wt%; 80-100 mesh 20-25wt%; 100-150 mesh 12-15wt%; 200-300 mesh 6-8wt%; The balance is 60-80 mesh; The standard for the proportioning of quartz sand in the high-permeability zone is as follows: 30-40 mesh 1-5wt%; 40-60 mesh 10-15wt%; 80-100 mesh 35-40wt%; 100-150 mesh 5-10wt%; 200-300 mesh 1-3wt%; The remaining weight is 60-80 mesh.

6. The method for determining the injection volume of a microbial single-well huff and puff activator according to claim 5, characterized in that, Step (2c) includes the following steps: Using the quartz sand gradation ratio determined in step (2b), five sets of simulated cores with ranges of 2, 4, 6, 8, and 10 were respectively filled, where: The permeability in the low-permeability zone is 450×10 -3 μm 2 ~550×10 -3 μm 2 ; The permeability in the high-permeability zone is 950×10 -3 μm 2 ~1050×10 -3 μm 2 1950×10 -3 μm 2 ~2050×10 -3 μm 2 2900×10 -3 μm 2 ~3100×10 -3 μm 2 3900×10 -3 μm 2 ~4100×10 -3 μm 2 4900×10 -3 μm 2 ~5100×10 -3 μm 2 .

Images