CN112431576B - Method for evaluating influence of carbon dioxide flooding asphaltene precipitation on recovery ratio - Google Patents
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Abstract
The invention belongs to the technical field of oil and gas field development, and provides a method for evaluating the influence of carbon dioxide flooding asphaltene precipitation on the recovery ratio. The method is to CO 2 On the basis of an experiment for driving asphaltene precipitation, a one-dimensional numerical model is established by using numerical simulation software to simulate core CO 2 And (4) displacement experiment. Using the bitumen reaction model, taking into account CO 2 The effect of asphaltene deposition on the core during flooding. Continuously adjusting parameters in a numerical model, correcting by using an object model experiment result, and establishing CO suitable for researching a sample 2 And (3) analyzing the influence of the asphaltene precipitation on the final recovery ratio by using an asphaltene precipitation one-dimensional model in the flooding process. The method has high repeatability and strong operability, and is convenient for oil field development technicians to master and apply.
Description
Technical Field
The invention belongs to the technical field of oil and gas field development, and particularly relates to a method for evaluating the influence of carbon dioxide flooding asphaltene precipitation on recovery ratio.
Background
In CO 2 CO injected in the oil displacement process 2 Dissolved in crude oil with CO 2 Increased concentration in crude oil, large amount of CO 2 The small molecules occupy the space on the surface of the asphaltene micelle, so that the micelle solvation layer formed by the asphaltene micelle cannot reach a certain thickness or form no micelle. The asphaltene molecules will further combine to form larger clusters, resulting in asphaltene flocculation and precipitation. And, as the injection pressure increases, CO 2 The dissolution amount in the crude oil is increased, the concentration of colloid serving as an asphaltene stabilizer is further reduced along with the increase of small molecular components in the crude oil, and asphaltene molecular groups are more easily combined to generate flocculation and precipitation.
The temperature rise is beneficial to the dissolution of the asphaltene in the crude oil, and simultaneously, the density of the crude oil is correspondingly reduced, so that the interaction force between the asphaltene and the colloid is weakened, the colloid molecules on the surface part of the asphaltene are desorbed, and the asphaltene loses the peripheral protection. In CO 2 During the displacement process, the asphaltene precipitation amount is continuously increased along with the increase of the pressure. The higher the original asphaltene content in the formation oil is, the larger the volume of the asphaltene colloid micelles in the formation oil is, the more the number of the asphaltene colloid micelles is, and the larger the shape of the formed asphaltene precipitate is under the same temperature and pressure conditions, the greater the influence on the permeability of the reservoir stratum is, and further the oil displacement effect of carbon dioxide is influenced, but an evaluation and calculation method for the influence of the asphaltene precipitate on the recovery ratio is lacked at present.
Disclosure of Invention
The invention aims to provide a method for evaluating the influence of carbon dioxide flooding asphaltene precipitation on recovery ratio. The technical problems in the prior art are overcome.
Therefore, the technical scheme provided by the invention is as follows:
a method for evaluating the influence of carbon dioxide flooding asphaltene precipitation on recovery ratio comprises the following steps:
step 1) collecting a target oil reservoir crude oil sample, and analyzing component composition;
step 2) carrying out interaction experiments of carbon dioxide and crude oil at different temperatures and different pressure differences to obtain asphaltene precipitation data generated by the carbon dioxide and the crude oil, and establishing a relational expression of temperature T, pressure difference delta P and asphaltene deposition amount;
step 3) obtaining different differential pressures and asphaltene deposition amounts under the conditions of target oil reservoir temperature and crude oil composition according to the relational expression of the temperature T, the differential pressure delta P and the asphaltene deposition amount;
step 4) establishing a one-dimensional numerical model of the physical properties of the target oil reservoir and the properties of the formation fluid by using Eclipse software;
step 5) inputting different pressure differences into the one-dimensional numerical model, and obtaining the asphaltene deposition amount of the crude oil of the target oil reservoir under different pressure differences according to an asphalt precipitation module in Eclipse software;
step 6) fitting the asphaltene deposition amount obtained in the experiment in the step 3) and the asphaltene deposition amount obtained by the one-dimensional numerical model in the step 5) to obtain a numerical model of carbon dioxide flooding asphaltene precipitation, and judging that the numerical model of carbon dioxide flooding asphaltene precipitation can be used for evaluating the recovery ratio of the target oil reservoir when the degree of fitting is not less than 0.9;
step 7) calculating the asphaltene precipitation consideration and the asphaltene precipitation non-consideration numerical model by utilizing the numerical model of the carbon dioxide flooding asphaltene precipitation, respectively outputting a recovery ratio curve of the asphaltene precipitation consideration and a recovery ratio curve of the asphaltene precipitation non-consideration, and then solving the correlation degree of the two curves;
and 8) when the correlation degree of the two curves is not less than 0.9, indicating that the asphaltene precipitation has no influence on the recovery ratio, and otherwise, indicating that the asphaltene precipitation has influence on the recovery ratio.
The relation of the temperature T, the pressure difference delta P and the deposition amount of the asphaltene in the step 2) is as follows:
y＝ae (bT+cΔp)
wherein a, b and c are constants; t is temperature, DEG C; Δ P is the differential pressure, MPa.
The process of establishing the one-dimensional numerical model of the physical properties of the target oil reservoir and the properties of the formation fluid by using Eclipse software in the step 4) is as follows:
and inputting the average porosity, permeability, original oil saturation, original pressure and formation temperature of a target oil reservoir into Eclipse software to generate a one-dimensional numerical model.
The specific process for obtaining the deposition amount of the asphaltene under different pressure differences according to the asphalt precipitation module in the Eclipse software in the step 5) is as follows:
under the condition that the reaction rate of asphaltene precipitation is not changed, the precipitation coefficient, the blockage coefficient and the carrying flow coefficient are adjusted, and the deposition amount of asphalt under different pressure differences is obtained by utilizing an asphalt precipitation module.
The asphaltene deposition amount calculation formula is as follows:
in the formula, epsilon i Represents the volume fraction of the precipitation amount of the asphaltene in the direction i without dimension; alpha represents the sedimentation coefficient, day -1 (ii) a d represents a correction coefficient without dimension; t represents a time variable; phi represents porosity, dimensionless; c a Represents the volume concentration,%, of the asphaltene aggregate state; f oi Represents Darcy flow, m 3 (ii) a Gamma denotes the clogging coefficient, m -3 (ii) a Beta represents the carry flow coefficient, m -3 ；U oi Represents the oil phase flow rate, m/day; u shape cr Represents the critical flow rate, m/day.
And 7) inputting deposition damage in a numerical model of the carbon dioxide flooding asphaltene precipitation when an asphaltene precipitation influence curve is output and considered in the step 7), wherein the deposition damage comprises the influence of the asphaltene precipitation on the porosity and the reservoir permeability.
The asphaltene precipitation reaction rate is determined through experiments or obtained through an asphaltene precipitation module, and the asphaltene precipitation reaction rate formula is as follows:
in the formula, R a Indicates the asphaltene precipitation reaction rate, day -1 ；r ia Indicates the asphaltene precipitation Rate, day -1 ；r ai Indicating the rate of asphaltene redissolution, day -1 ；C a Represents the volume concentration,%, of the asphaltene aggregate state; c i Denotes the volume concentration,%, of the asphaltene particles.
The effect of asphaltene deposition on porosity is calculated by the following formula:
phi denotes porosity after being affected by asphaltene deposition; phi is a 0 Represents the initial porosity, dimensionless; ε represents the volume fraction of asphaltene deposition, dimensionless.
The effect of asphaltene deposition on reservoir permeability was calculated by the following formula:
in the formula, delta represents a permeability injury index and has no dimension; epsilon represents the volume fraction of the deposition amount of asphaltene, and has no dimension; phi is a 0 Represents initial porosity, dimensionless; k represents the current absolute permeability, mD; k is a radical of 0 Representing the original absolute permeability, mD.
The beneficial effects of the invention are:
the method for evaluating the influence of the carbon dioxide flooding asphaltene precipitation on the recovery ratio provided by the invention fully combines the oil reservoir geological research result, and analyzes the influence of the carbon dioxide flooding asphaltene precipitation on the ultimate recovery ratio by theoretical analysis and experimental research and adopting numerical simulation calculation.
The method is to CO 2 On the basis of an experiment of asphaltene precipitation caused by flooding, numerical simulation software is used for establishing a one-dimensional numerical model and simulating core CO 2 And (4) displacement experiment. Using the bitumen reaction model, taking into account CO 2 The effect of asphaltene deposition on the core during flooding. At a value ofContinuously adjusting parameters in the model, correcting by using the experimental result of the object model, and establishing CO suitable for researching the sample 2 And (3) analyzing the influence of the asphaltene precipitation on the final recovery ratio by using an asphaltene precipitation one-dimensional model in the flooding process. The method has high repeatability and strong operability, and is convenient for oil field development technicians to master and apply.
This will be described in further detail below with reference to the accompanying drawings.
Drawings
FIG. 1 is a graph comparing results of numerical model calculations and experimental results of asphaltene precipitation;
FIG. 2 is a plot of model calculations versus modeled asphaltene-considered versus non-considered asphaltene precipitation recovery.
Detailed Description
The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.
The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention.
Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In addition, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their context in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
Example 1:
the embodiment provides a method for evaluating the influence of carbon dioxide flooding asphaltene precipitation on recovery ratio, which comprises the following steps:
step 1) collecting a target oil reservoir crude oil sample, and analyzing component composition;
step 2) carrying out interaction experiments of carbon dioxide and crude oil at different temperatures and different pressure differences to obtain asphaltene precipitation data generated by the carbon dioxide and the crude oil, and establishing a relational expression of temperature T, pressure difference delta P and asphaltene deposition amount;
step 3) obtaining different differential pressures and asphaltene deposition amounts under the conditions of target oil reservoir temperature and crude oil composition according to the relational expression of the temperature T, the differential pressure delta P and the asphaltene deposition amount;
step 4) establishing a one-dimensional numerical model of the physical properties of the target oil reservoir and the properties of the formation fluid by using Eclipse software;
step 5) inputting different pressure differences into the one-dimensional numerical model, and obtaining the asphaltene deposition amount of the crude oil of the target oil reservoir under different pressure differences according to an asphalt precipitation module in Eclipse software;
step 6) fitting the asphaltene deposition amount obtained in the experiment in the step 3) and the asphaltene deposition amount obtained by the one-dimensional numerical model in the step 5) to obtain a numerical model of carbon dioxide flooding asphaltene precipitation, and when the degree of fitting is not less than 0.9, judging that the numerical model of carbon dioxide flooding asphaltene precipitation can be used for evaluating the recovery ratio of the target oil reservoir;
step 7) calculating the asphaltene precipitation consideration and the asphaltene precipitation non-consideration numerical model by utilizing the numerical model of the carbon dioxide flooding asphaltene precipitation, respectively outputting a recovery ratio curve of the asphaltene precipitation consideration and a recovery ratio curve of the asphaltene precipitation non-consideration, and then solving the correlation degree of the two curves;
and 8) when the correlation degree of the two curves is not less than 0.9, indicating that the asphaltene precipitation has no influence on the recovery ratio, and otherwise, indicating that the asphaltene precipitation has influence on the recovery ratio.
The principle of the invention is as follows:
developing an experiment of generating asphaltene precipitation through reaction of carbon dioxide and crude oil, establishing a one-dimensional numerical model based on experimental data, target reservoir physical properties and formation fluid properties, and simulating core CO by using numerical simulation software 2 And (4) a displacement experiment, namely evaluating the influence of asphaltene precipitation on the final recovery ratio of the carbon dioxide flooding.
In CO 2 CO injected in the oil displacement process 2 Dissolved in crude oil with CO 2 Increased concentration in crude oil, large amount of CO 2 The small molecules occupy the space on the surface of the asphaltene micelle, so that the concentration of colloid is relatively reduced, and thus a micelle solvation layer formed by the asphaltene micelle cannot reach a certain thickness or form no micelle. The asphaltene molecules will further combine to form larger clusters, resulting in asphaltene flocculation and precipitation. And, as the injection pressure increases, CO 2 The dissolution amount in the crude oil is increased, the concentration of colloid serving as an asphaltene stabilizer is further reduced along with the increase of small molecular components in the crude oil, and asphaltene molecular groups are more easily combined to generate flocculation and precipitation.
Critical pressure for asphaltene precipitation, CO, determined by carbon dioxide and crude oil reaction experiments 2 Minimum miscible pressure of crude oil system, and CO 2 Crude oil composition conditions. CO 2 2 The material base of asphaltene precipitation in the flooding process is CO 2 The asphalt is fully contacted with the components of crude oil containing the asphaltene, then the pressure condition (critical pressure) under which the asphaltene is separated out and the pressure (minimum miscible pressure) under which the asphaltene separation amount begins to decrease are adopted, and whether the asphaltene precipitation is generated or not can be visually judged through an interaction experiment of carbon dioxide and the crude oil.
If the correlation degree between the recovery curve of considering the asphaltene and the recovery curve of not considering the asphaltene precipitation is more than 0.9, the asphaltene precipitation does not influence the recovery efficiency; if the correlation between the recovery curve of the recovery factor of the considered asphaltene and the recovery curve of the non-considered asphaltene precipitation is less than 0.9, the asphaltene precipitation influences the recovery factor, and the asphaltene precipitation amount must be calculated in the recovery factor prediction.
Example 2:
on the basis of example 1, this example provides a method for evaluating the influence of carbon dioxide flooding on the recovery ratio of asphaltene precipitation, and the relationship between temperature T and pressure difference Δ P in step 2) and the deposition amount of asphaltene is as follows:
y＝ae (bT+cΔp)
wherein a, b and c are constants; t is temperature, DEG C; Δ P is the differential pressure, MPa.
In the embodiment, a calculation expression of the deposition amount of the asphaltene after the carbon dioxide and the crude oil are reacted is established according to experimental data. The deposition amount of asphaltene is exponential with both temperature and pressure difference. Three groups of data are substituted in the formula, and three constant values of a, b and c can be obtained.
Example 3:
on the basis of example 1, this example provides a method for evaluating the influence of carbon dioxide flooding asphaltene precipitation on recovery efficiency, and the process of establishing a one-dimensional numerical model of the target reservoir physical property and formation fluid property by using Eclipse software in step 4) is as follows:
and inputting the average porosity, permeability, original oil saturation, original pressure and formation temperature of a target oil reservoir into Eclipse software to generate a one-dimensional numerical model.
Each parameter is shown in table 3, and a one-dimensional numerical model is automatically generated after the parameter is input by Eclipse software.
Example 4:
on the basis of example 1, this example provides a method for evaluating the influence of carbon dioxide flooding asphaltene precipitation on recovery efficiency, and the specific process of obtaining the asphaltene deposition amount under different pressure differences according to the asphaltene precipitation module in Eclipse software in step 5) is as follows:
under the condition that the reaction rate of asphaltene precipitation is not changed, the precipitation coefficient, the blockage coefficient and the carrying flow coefficient are adjusted, and the deposition amount of asphalt under different pressure differences is obtained by utilizing an asphalt precipitation module.
Continuously adjusting parameters (sedimentation coefficient, blockage coefficient and carrying flow coefficient) in a one-dimensional numerical model, correcting by using an object model experiment result, and establishing CO suitable for researching a sample 2 And (3) carrying out an asphaltene precipitation one-dimensional model in the flooding process to analyze the influence of asphaltene precipitation on the ultimate recovery ratio.
Example 5:
on the basis of example 1 or 4, this example provides a method for evaluating the effect of carbon dioxide flooding on the recovery ratio of asphaltene deposits, which is calculated as follows:
in the formula, epsilon i Represents the volume fraction of the precipitation amount of the asphaltene in the direction i without dimension; a represents the sedimentation coefficient, day -1 (ii) a d represents a correction coefficient without dimension; t represents a time variable; phi represents porosity, dimensionless; c a Represents the volume concentration,%, of the asphaltene aggregate state; f oi Represents Darcy flow, m 3 (ii) a Gamma denotes the plugging coefficient, m -3 (ii) a Beta represents the carry flow coefficient, m -3 ；U oi Represents the oil phase flow rate, m/day; u shape cr Represents the critical flow rate, m/day.
The deposition amount of asphaltene is composed of three parts of precipitation deposition, blockage deposition and re-transportation. The deposition condition of the asphaltene is characterized by the asphaltene sedimentation coefficient, the asphaltene blockage coefficient and the carrying flow coefficient.
Example 6:
on the basis of example 1, this example provides a method for evaluating the influence of carbon dioxide flooding asphaltene precipitation on recovery efficiency, and in step 7), when the influence curve of asphaltene precipitation on recovery efficiency is taken into consideration, deposition damage is input in a numerical model of carbon dioxide flooding asphaltene precipitation, wherein the deposition damage comprises the influence of asphaltene precipitation on porosity and reservoir permeability.
The numerical model of the carbon dioxide flooding asphaltene precipitation comprises a precipitation judgment condition, asphaltene precipitation amount calculation and precipitation damage calculation.
And (3) deposition judgment conditions:
determining asphaltene precipitation critical pressure, CO, according to physical experiments 2 Minimum miscible pressure of crude oil system, and CO 2 The composition condition of crude oil is three parts. CO 2 2 The material base of asphaltene precipitation in the flooding process is CO 2 The asphalt is fully contacted with the components of crude oil containing the asphaltene, then the pressure condition (critical pressure) under which the asphaltene is separated out and the pressure (minimum miscible pressure) under which the asphaltene separation amount begins to decrease are adopted, and whether the asphaltene precipitation is generated or not can be visually judged through an interaction experiment of carbon dioxide and the crude oil.
Asphaltene precipitation amount:
the asphaltene precipitation amount under different conditions is calculated by expressing the asphaltene component precipitation rate and the forward and reverse reaction rate of the asphaltene component precipitation to form the aggregate.
Asphaltene deposition amount:
consists of three parts of precipitation deposition, blocking deposition and re-transportation. The deposition condition of the asphaltene is characterized by the asphaltene sedimentation coefficient, the asphaltene blockage coefficient and the carrying flow coefficient.
In the formula, epsilon i Represents the volume fraction of the precipitation amount of the asphaltene in the direction i without dimension; a represents the sedimentation coefficient, day -1 (ii) a d represents a correction coefficient without dimension; t represents a time variable; phi represents porosity, dimensionless; c a Represents the volume concentration,%, of the asphaltene aggregate state; f oi Represents Darcy flow, m 3 (ii) a Gamma denotes the plugging coefficient, m -3 (ii) a Beta represents the carry flow coefficient, m -3 ；U oi Represents the oil phase flow rate, m/day; u shape cr Represents the critical flow rate, m/day.
Deposition damage:
including the effect of asphaltene deposition on porosity and permeability.
Example 7:
on the basis of example 4, this example provides a method for evaluating the effect of carbon dioxide flooding asphaltene precipitation on recovery ratio, wherein the asphaltene precipitation reaction rate is determined experimentally or obtained by an asphaltene precipitation module, and the formula of the asphaltene precipitation reaction rate is as follows:
in the formula, R a Indicates the reaction rate of asphaltene precipitation, day -1 ；r ia Indicates the asphaltene precipitation Rate, day -1 ；r ai Indicating the rate of asphaltene redissolution, day -1 ；C a Represents the volume concentration,%, of the asphaltene aggregate state; c i Represents the volume concentration,%, of asphaltene particles.
Example 8:
on the basis of example 6, this example provides a method for evaluating the effect of carbon dioxide flooding of asphaltene precipitation on recovery efficiency, the effect of asphaltene precipitation on porosity being calculated by the following formula:
phi denotes porosity after being affected by asphaltene deposition; phi is a 0 Represents initial porosity, dimensionless; ε represents the asphaltene deposition volume fraction without dimension.
The effect of asphaltene deposition on reservoir permeability was calculated by the following formula:
in the formula, delta represents a permeability injury index and has no dimension; epsilon represents the volume fraction of the deposition amount of asphaltene, and has no dimension; phi is a unit of 0 Represents initial porosity, dimensionless; k represents the current absolute permeability, mD; k is a radical of 0 Representing the original absolute permeability, mD.
Through the model deposition judgment condition, the asphaltene precipitation amount calculation, the asphaltene deposition amount calculation and the deposition damage calculation, the evaluation of the four parts can be carried out on CO 2 The rate of asphaltene deposition during flooding is affected. And determining asphaltene precipitation conditions and parameters required in the deposition amount calculation process according to the related experimental results of the asphaltene deposition of the crude oil and the rock core in the research block, thereby ensuring that the asphaltene deposition model effect is consistent with the experimental results.
Example 9:
based on example 1, this example will explain the present invention in detail by taking a certain reservoir as an example, and the steps are as follows:
step 1) crude oil component analysis: and collecting a crude oil sample of the target oil reservoir, and analyzing the composition of crude oil components. See table 1.
TABLE 1 crude oil component analysis Table
| Components | Mole fraction (%) | Components | Mole fraction (%) |
| CO 2 | 0.08 | C 17 | 1.85 |
| N 2 | 1.03 | C 18 | 1.55 |
| C 1 | 29.99 | C 19 | 1.48 |
| C 2 | 8.84 | C 20 | 1.17 |
| C 3 | 7.36 | C 21 | 1.14 |
| iC 4 | 0.79 | C 22 | 1.02 |
| nC 4 | 1.58 | C 23 | 1 |
| iC 5 | 1.57 | C 24 | 0.85 |
| nC 5 | 1.8 | C 25 | 0.86 |
| C 6 | 1.81 | C 26 | 0.84 |
| C 7 | 1.77 | C 27 | 0.87 |
| C 8 | 2.92 | C 28 | 0.82 |
| C 9 | 3.05 | C 29 | 0.74 |
| C 10 | 3.01 | C 30 | 0.63 |
| C 11 | 2.78 | C 31 | 0.51 |
| C 12 | 2.88 | C 32 | 0.42 |
| C 13 | 2.71 | C 33 | 0.37 |
| C 14 | 2.73 | C 34 | 0.33 |
| C 15 | 2.19 | C 35 | 0.3 |
| C 16 | 2.03 | C 36+ | 2.33 |
| General assembly | 100 | Asphaltene content (%) | 0.0195 |
Step 2) interaction experiment of carbon dioxide and crude oil
At different temperatures, different pressures and CO 2 Under the condition of injection amount, crude oil and CO 2 The gases reacted and it was judged that pitch precipitation occurred, see table 2.
Table 2 experimental reaction results table
The statistic generated experimental data of each sample shows that the deposition amount of asphaltene has an exponential relation with temperature and pressure difference, and CO can be established 2 The asphaltene precipitation index type characterization method after the reaction with crude oil comprises the following steps:
y＝0.00972e (0.000846T+0.0085469Δp)
step 3) calculation of asphaltene precipitation amount of target oil reservoir
Calculating the asphaltene precipitation amount corresponding to the target oil reservoir temperature of 80 ℃ and different pressures according to the relational expression generated in the step 2).
Step 4) establishing a one-dimensional model
And establishing a one-dimensional numerical model according to basic parameters such as the average porosity, the permeability, the original oil saturation, the original pressure, the formation temperature and the like of the target oil reservoir, and referring to table 3.
TABLE 3 one-dimensional model basis parameters
Step 5) establishing a numerical model of carbon dioxide flooding asphaltene precipitation
First determining the asphaltene precipitation reaction rate R using an asphalt precipitation module a And fitting the one-dimensional numerical model under different pressure conditions with the experimental data in the step 3) by continuously adjusting the sedimentation coefficient, the blockage coefficient and the carrying flow coefficient in the attached table 4.
TABLE 4 carbon dioxide flooding asphaltene precipitation model parameters
As shown in fig. 1, the experimental data are consistent with the digital-analog calculation result, which shows that the model established in step 5) can quantitatively and accurately represent the carbon dioxide flooding asphaltene precipitation.
Step 6) influence of carbon dioxide flooding asphaltene precipitation on recovery ratio
And 5) calculating the recovery ratio under the condition of considering the asphaltene precipitation and not considering the asphaltene precipitation by using the model established in the step 5), and evaluating the influence of the asphaltene precipitation on the recovery ratio.
See fig. 2. The correlation degree of the recovery curve of the recovery factor of the considered asphaltene and the recovery factor of the precipitation of the not considered asphaltene reaches 0.999, which shows that the influence of the asphaltene on the recovery factor is small, and the precipitation amount of the asphaltene does not need to be calculated in the recovery factor prediction.
The above examples are merely illustrative of the present invention and should not be construed as limiting the scope of the invention, which is intended to be covered by the claims and any design similar or equivalent to the scope of the invention.
Claims (9)
1. A method for evaluating the influence of carbon dioxide flooding asphaltene precipitation on recovery ratio is characterized by comprising the following steps:
step 1) collecting a target oil reservoir crude oil sample, and analyzing component composition;
step 2) carrying out interaction experiments of carbon dioxide and crude oil at different temperatures and different pressure differences to obtain asphaltene precipitation data generated by the carbon dioxide and the crude oil, and establishing a relational expression of temperature T, pressure difference delta P and asphaltene deposition amount;
step 3) obtaining different differential pressures and asphaltene deposition amounts under the conditions of target oil reservoir temperature and crude oil composition according to the relational expression of the temperature T, the differential pressure delta P and the asphaltene deposition amount;
step 4) establishing a one-dimensional numerical model of the physical properties of the target oil reservoir and the properties of the formation fluid by using Eclipse software;
step 5) inputting different pressure differences into the one-dimensional numerical model, and obtaining the asphaltene deposition amount of the crude oil of the target oil reservoir under different pressure differences according to an asphalt precipitation module in Eclipse software;
step 6) fitting the asphaltene deposition amount obtained in the experiment in the step 3) and the asphaltene deposition amount obtained by the one-dimensional numerical model in the step 5) to obtain a numerical model of carbon dioxide flooding asphaltene precipitation, and judging that the numerical model of carbon dioxide flooding asphaltene precipitation can be used for evaluating the recovery ratio of the target oil reservoir when the degree of fitting is not less than 0.9;
step 7) calculating the numerical model considering the asphaltene precipitation and the numerical model not considering the asphaltene precipitation by using the numerical model of the carbon dioxide flooding asphaltene precipitation, respectively outputting a curve considering the asphaltene precipitation recovery ratio and a curve not considering the asphaltene precipitation recovery ratio, and then calculating the correlation of the two curves;
and 8) when the correlation degree of the two curves is not less than 0.9, indicating that the asphaltene precipitation has no influence on the recovery ratio, and otherwise, indicating that the asphaltene precipitation has influence on the recovery ratio.
2. The method for evaluating the effect of carbon dioxide flooding on the recovery ratio of asphaltene precipitation according to claim 1, wherein the relationship between temperature T, pressure difference Δ P and the amount of asphaltene deposition in step 2) is as follows:
y＝ae (bT+cΔp)
wherein a, b and c are constants; t is temperature, DEG C; Δ P is the differential pressure, MPa.
3. The method for evaluating the effect of carbon dioxide flooding asphaltene precipitation on recovery efficiency according to claim 1, wherein the Eclipse software is applied in the step 4) to establish a one-dimensional numerical model of the target reservoir properties and formation fluid properties as follows:
and (3) inputting the average porosity, permeability, original oil saturation, original pressure and formation temperature of a target oil reservoir into Eclipse software to generate a one-dimensional numerical model.
4. The method for evaluating the influence of carbon dioxide flooding asphaltene precipitation on recovery ratio according to claim 1, wherein the specific process for obtaining the asphaltene deposition amount under different pressure differences according to the asphaltene precipitation module in Eclipse software in the step 5) is as follows:
under the condition that the reaction rate of asphaltene precipitation is not changed, the precipitation coefficient, the blockage coefficient and the carrying flow coefficient are adjusted, and the deposition amount of asphalt under different pressure differences is obtained by utilizing an asphalt precipitation module.
5. The method for evaluating the effect of carbon dioxide flooding on the recovery ratio of asphaltene precipitation according to claim 1 or 4, wherein the amount of asphaltene deposition is calculated as follows:
in the formulaAnd epsilon represents the volume fraction of the precipitation amount of asphaltenes in the i direction, and has no dimension; alpha represents the sedimentation coefficient, day -1 (ii) a d represents a correction coefficient without dimension; t represents a time variable; phi represents porosity, dimensionless; c a Represents the volume concentration,%, of the asphaltene aggregate state; f oi Represents Darcy flow, m 3 (ii) a Gamma denotes the plugging coefficient, m -3 (ii) a Beta represents the carry flow coefficient, m -3 ；U 0i Represents the flow velocity of the oil phase, m 3 /day；U cr Represents the critical flow velocity, m 3 /day。
6. The method of evaluating the effect of carbon dioxide flooding asphaltene precipitation on recovery factor of claim 1, wherein: and 7) inputting deposition damage in a numerical model of the carbon dioxide flooding asphaltene precipitation when an asphaltene precipitation influence curve is output and considered in the step 7), wherein the deposition damage comprises the influence of the asphaltene precipitation on the porosity and the reservoir permeability.
7. The method of evaluating the effect of carbon dioxide flooding asphaltene precipitation on recovery factor of claim 4, wherein: the asphaltene precipitation reaction rate is determined through experiments or obtained through an asphaltene precipitation module, and the asphaltene precipitation reaction rate formula is as follows:
in the formula, R a Indicates the reaction rate of asphaltene precipitation, day -1 ；r ia Indicates the asphaltene precipitation Rate, day -1 ；r ai Indicating the rate of asphaltene redissolution, day -1 ；C a Represents the volume concentration,%, of the asphaltene aggregate state; c i Represents the volume concentration,%, of asphaltene particles.
8. The method of evaluating the effect of carbon dioxide flooding of asphaltene precipitation on recovery factor of claim 6, wherein the effect of asphaltene deposition on porosity is calculated by the formula:
phi denotes porosity after being affected by asphaltene deposition; phi is a 0 Represents the initial porosity, dimensionless; ε represents the asphaltene deposition volume fraction without dimension.
9. The method of evaluating the effect of carbon dioxide flooding asphaltene precipitation on recovery factor of claim 6, wherein the effect of asphaltene deposition on reservoir permeability is calculated by:
in the formula, delta represents a permeability injury index and has no dimension; epsilon represents the volume fraction of the deposition amount of asphaltene, and has no dimension; phi is a 0 Represents initial porosity, dimensionless; k represents the current absolute permeability, mD; k is a radical of 0 Representing the original absolute permeability, mD.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2132041A1 (en) * | 1993-09-21 | 1995-03-22 | Abul K. M. Jamaluddin | Process for removing and preventing near-wellbore damage due to asphaltene precipitation |
| WO2010148204A2 (en) * | 2009-06-17 | 2010-12-23 | University Of Massachusetts | Particle stabilized emulsions for extraction of hydrocarbons from oil sands and oil shale |
| CN107941838A (en) * | 2017-11-14 | 2018-04-20 | 西安石油大学 | The quantitative evaluation method that a kind of carbon dioxide drive process studies on asphaltene precipitation device to hole larynx distribution influences |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2132041A1 (en) * | 1993-09-21 | 1995-03-22 | Abul K. M. Jamaluddin | Process for removing and preventing near-wellbore damage due to asphaltene precipitation |
| WO2010148204A2 (en) * | 2009-06-17 | 2010-12-23 | University Of Massachusetts | Particle stabilized emulsions for extraction of hydrocarbons from oil sands and oil shale |
| CN107941838A (en) * | 2017-11-14 | 2018-04-20 | 西安石油大学 | The quantitative evaluation method that a kind of carbon dioxide drive process studies on asphaltene precipitation device to hole larynx distribution influences |
Non-Patent Citations (2)
| Title |
|---|
| CO_2驱沥青质沉积对致密储层的伤害机理――以鄂尔多斯盆地延长组长8储层为例;乞照等;《断块油气田》;20200525(第03期);全文 * |
| 基于最小二乘支持向量机的二氧化碳驱油沥青质沉积对储层伤害的动态分析;吴君达等;《科学技术与工程》;20200828(第24期);全文 * |
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