WO2023123977A1

WO2023123977A1 - Crude oil pseudocomponents, acquisition method thereof, and air injection reservoir development determination method based on crude oil component analysis

Info

Publication number: WO2023123977A1
Application number: PCT/CN2022/102994
Authority: WO
Inventors: 黄伟强; 张霞; 郑爱萍; 宋栋; 张卫国; 宋文志; 冀楠; 李宁
Original assignee: 中国石油天然气股份有限公司
Priority date: 2021-12-31
Filing date: 2022-06-30
Publication date: 2023-07-06
Also published as: CN116411957A

Abstract

The present invention provides crude oil pseudocomponents, an acquisition method thereof, and an air injection reservoir development determination method based on crude oil component analysis. A first crude oil pseudocomponent is formed by mixing, within a narrow distillate group of a target crude oil, each narrow distillate which has an oxidation rate with a negative temperature coefficient interval and which is fluid at the temperature of a reservoir. A second crude oil pseudocomponent is formed by mixing, within a narrow distillate group of the target crude oil, each narrow distillate which has an oxidation rate without a negative temperature coefficient interval and which is fluid at the temperature of the reservoir. A third crude oil pseudocomponent is formed by mixing, within a narrow distillate group of the target crude oil, each narrow distillate which has an oxidation rate with a negative temperature coefficient interval and which is not fluid at the temperature of the reservoir. A fourth crude oil pseudocomponent is formed by mixing, within a narrow distillate group of the target crude oil, each narrow distillate which has an oxidation rate without a negative temperature coefficient interval and which is not fluid at the temperature of the reservoir.

Description

Crude oil pseudo-components and its acquisition method, and determination method of reservoirs developed by air injection based on analysis of crude oil components

technical field

The invention belongs to the technical field of heavy oil development, and in particular relates to a method for obtaining pseudo-components of crude oil, a method for determining pseudo-components of crude oil and an air injection development reservoir based on analysis of crude oil components.

Background technique

In the modeling analysis of the development of crude oil injection into air, it is necessary to clarify which components participate in which chemical reactions and what are produced after the reactions during the entire displacement process. Crude oil is a complex mixture of a large number of hydrocarbons and non-hydrocarbon compounds, and there are two main difficulties in determining its chemical composition: (1) the components are extremely complex, and the relative molecular weights vary greatly from tens to thousands; There are many isomers; (2) There are a lot of mixed structure molecules. At the same time, every time a component and its reaction equation are added to the numerical model, the calculation time will increase geometrically.

Currently, there are mainly three types of classification methods for crude oil components:

(1) Four-component method (SARA method)——divide crude oil into four components: saturated hydrocarbons, aromatic hydrocarbons, colloids, and asphaltenes, among which asphaltene is the non-hydrocarbon with the largest relative molecular weight and the strongest polarity in crude oil Colloids are macromolecular non-hydrocarbon compounds that are second only to asphaltenes in relative molecular weight and polarity in crude oil.

(2) Distillation method—crude oil is divided according to the boiling point. Among them, the distillate oil with a boiling point range below 200°C is called light fraction, the distillate oil with a boiling point range of 200-350°C is called middle fraction, and the distillate oil above 350°C is called heavy fraction.

(3) Minimal model—crude oil is divided into heavy oil, light oil, and coke.

In the four-component method, there are frequent conversions between colloids and asphaltene, which is difficult to realize in actual simulation. In order to make up for this defect, the general thermal recovery simulation software——CMG’s STARS software uses carbon number as the basis for division. C33-C60 is classified as asphalt, C20-C32 is classified as colloids and aromatics, and C2-C19 is classified as saturated hydrocarbons. The four-component method uses carbon number as the component division unit, and combines the advantages of the SARA model, which can clearly describe the oxidation reaction in the fire flooding process.

So far, the four-component method has not been applied to the numerical simulation of air injection development. The main reasons are: first, the components divided by the carbon number do not match the oxidation activity. According to the above four-component method, C10 and C36 should be included in different pseudo-components, but at the same temperature and pressure, they tend to The same low-temperature oxidation and high-temperature combustion mode, that is, from the perspective of oxidation reaction, they should be combined into the same pseudo-component; paraffinic C20 hydrocarbons and aromatic C20 hydrocarbons have the same number of carbon atoms, but the paraffinic low temperature range Internal combustion, while aromatics burn in high-temperature regions, the oxidation activity is very different, as shown in Figure 1, from the perspective of oxidation, they should not be combined into the same pseudo-component; second, the thermochemical The reaction process and oil recovery mechanism in the flooding process make the research process extremely complicated; third, the transition conditions from low-temperature oxidation to high-temperature oxidation are not considered.

At present, the fractionation method has not been used in the mechanism analysis and numerical simulation research of air injection development.

The Minimal model is currently the most simple and practical air injection development analysis model, but it has serious shortcomings: first, the fuel only comes from the cracking of heavy oil; second, the same heavy oil, the fire flooding mechanism of saturated hydrocarbons and aromatic hydrocarbons is very different , there are large errors in using heavy oil, light oil, and coke to divide crude oil. In order to make up for the lack of consideration of the mechanism of low-temperature oxidation of crude oil in the Minimal model, in 2006 a component of fuel coke generated by low-temperature oxidation of crude oil was supplemented. Although this improvement is beneficial to the understanding of the development mechanism of air injection, this model has not been widely used in related mechanism and numerical simulation studies due to the large ambiguity in the research field of coke 1 production mechanism and oxidation mode.

The above-mentioned traditional method of dividing components based on carbon number cannot or is difficult to be applied to reservoir engineering and numerical simulation calculations, nor can it intuitively and concisely display the reaction process and oil recovery mechanism of crude oil in the air injection development process; only considering The low-temperature oxidation process and the high-temperature oxidation process cannot reflect the whole process of oxidation reaction, so it is impossible to determine the reservoir suitable for air injection development through the analysis and construction of crude oil components. At present, there is no particularly suitable method to screen the reservoirs suitable for air injection development, resulting in many failure cases of air injection production. In addition, the production failures in heavy oil air injection production due to the inconsistency between the previous simulation and the field production process are also abound.

Contents of the invention

The purpose of the present invention is to provide crude oil quasi-components and its obtaining method which can be effectively used to solve the problem of on-site crude oil recovery in air injection development.

Another object of the present invention is to provide a reservoir determination method for air injection development that helps to promote the smooth progress of on-site air injection development.

In order to achieve the above object, in the first aspect, the present invention provides a crude oil pseudo-component, wherein the crude oil pseudo-component is composed of a narrow fraction oil group of the target crude oil, the oxidation rate has a negative temperature coefficient range and at the reservoir temperature Liquid narrow distillates are formed by mixing.

In a preferred embodiment of the first aspect, the distillation range temperature range of the narrow distillate is 25°C;

For example, the narrow distillate group includes distillate oils with a distillation range greater than or equal to 100°C and less than 125°C, distillate oils with a distillation range of greater than or equal to 125°C and less than 150°C, distillate oils with a distillation range of greater than or equal to 150°C and less than 175°C, and distillate oils with a distillation range greater than or equal to 150°C and less than 175°C, Distillate oil with a distillation range of 175°C less than 200°C, and distillate oil with a distillation range of 200°C or greater than 225°C; further, the narrow fraction oil group includes distillate oil with a distillation range of less than 100°C.

In a preferred embodiment of the first aspect, the narrow distillate oil with a viscosity not exceeding 500 mPa·s has fluidity at the reservoir temperature, and the narrow distillate oil with a viscosity greater than 500 mPa·s has no fluidity.

In a preferred embodiment of the first aspect, the narrow distillate oil with a distillation range temperature below 200°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature greater than 200°C has no fluidity at the reservoir temperature.

In a preferred embodiment of the first aspect, the narrow distillate oil with a distillation range temperature below 300°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature greater than 300°C has no fluidity at the reservoir temperature.

In a second aspect, the present invention provides a crude oil pseudo-component, wherein the crude oil pseudo-component consists of a narrow fraction oil group of the target crude oil, the oxidation rate does not have a negative temperature coefficient range and has fluidity at the reservoir temperature Individual narrow distillates are blended to form.

In a preferred embodiment of the second aspect, the distillation range temperature range of the narrow distillate is 25°C;

In a preferred embodiment of the second aspect, the narrow distillate oil with a viscosity not exceeding 500 mPa·s has fluidity at the reservoir temperature, and the narrow distillate oil with a viscosity greater than 500 mPa·s has no fluidity.

In a preferred embodiment of the second aspect, the narrow distillate oil with a distillation range temperature below 200°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature above 200°C has no fluidity at the reservoir temperature .

In a preferred embodiment of the second aspect, the narrow distillate oil with a distillation range temperature below 300°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature above 300°C has no fluidity at the reservoir temperature .

In a preferred embodiment, the narrow distillate oil with a distillation range temperature below 200°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature above 200°C has no fluidity at the reservoir temperature.

In a preferred embodiment, the narrow distillate oil with a distillation range temperature below 300°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature above 300°C has no fluidity at the reservoir temperature.

In a third aspect, the present invention provides a crude oil pseudo-component, wherein the crude oil pseudo-component is composed of a narrow fraction oil group of the target crude oil, the oxidation rate has a negative temperature coefficient range and does not have fluidity at the reservoir temperature Individual narrow distillates are blended to form.

In a preferred embodiment of the third aspect, the distillation range temperature range of the narrow distillate is 25°C;

In a preferred embodiment of the third aspect, the narrow distillate oil with a viscosity not exceeding 500 mPa·s has fluidity at the reservoir temperature, and the narrow distillate oil with a viscosity greater than 500 mPa·s has no fluidity.

In a preferred embodiment of the third aspect, the narrow distillate oil with a distillation range temperature below 200°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature greater than 200°C has no fluidity at the reservoir temperature .

In a preferred embodiment of the third aspect, the narrow distillate oil with a distillation range temperature below 300°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature greater than 300°C has no fluidity at the reservoir temperature .

In a fourth aspect, the present invention provides a crude oil pseudo-component, wherein the crude oil pseudo-component is composed of a narrow fraction oil group of the target crude oil, the oxidation rate does not have a negative temperature coefficient range and does not have fluidity at the reservoir temperature The various narrow distillates are mixed to form.

In a preferred embodiment of the fourth aspect, the distillation range temperature range of the narrow distillate is 25°C;

In a preferred embodiment of the fourth aspect, the narrow distillate oil with a viscosity not exceeding 500 mPa·s has fluidity at the reservoir temperature, and the narrow distillate oil with a viscosity greater than 500 mPa·s has no fluidity.

In a preferred embodiment of the fourth aspect, the narrow distillate oil with a distillation range temperature below 200°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature greater than 200°C has no fluidity at the reservoir temperature .

In a preferred embodiment of the fourth aspect, the narrow distillate oil with a distillation range temperature below 300°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature greater than 300°C has no fluidity at the reservoir temperature .

In a fifth aspect, the present invention provides a method for obtaining crude oil quasi-components, wherein the method includes:

Obtain the narrow distillate group of the target crude oil;

Carry out oxidation kinetics test to each narrow distillate oil in the narrow distillate oil group, determine whether the oxidation rate of each narrow distillate oil has negative temperature coefficient interval (that is, NTC interval); Store each narrow distillate oil in the narrow distillate oil group Fluidity test at reservoir temperature to determine whether each narrow distillate has fluidity at reservoir temperature;

Based on whether the oxidation rate of each narrow fraction of the target crude oil has a negative temperature coefficient range and whether each narrow fraction has fluidity at the reservoir temperature, the pseudo-component of the target crude oil is obtained; where,

The oxidation rate has a negative temperature coefficient interval and each narrow distillate oil with fluidity at the reservoir temperature is mixed to form the first pseudo-component of the target crude oil;

The oxidation rate does not have a negative temperature coefficient interval and the narrow distillates with fluidity at the reservoir temperature are mixed to form the second pseudo-component of the target crude oil;

The narrow fractions whose oxidation rate has a negative temperature coefficient interval and have no fluidity at the reservoir temperature are mixed to form the third pseudo-component of the target crude oil;

The narrow distillates whose oxidation rates do not have a negative temperature coefficient range and which do not have fluidity at the reservoir temperature mix to form the fourth pseudo-component of the target crude oil.

In a preferred embodiment of the fifth aspect, the distillation range temperature range of the narrow distillate is 25°C;

In a preferred embodiment of the fifth aspect, the narrow distillate oil with a viscosity not exceeding 500 mPa·s has fluidity at the reservoir temperature, and the narrow distillate oil with a viscosity greater than 500 mPa·s has no fluidity.

Among them, the narrow distillates that do not have fluidity at the reservoir temperature can be considered as medium-heavy narrow distillates, and the narrow distillates that have fluidity at the reservoir temperature can be considered as light narrow distillates.

In a preferred embodiment of the fifth aspect, the narrow distillate oil with a distillation range temperature below 200°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature greater than 200°C has no fluidity at the reservoir temperature .

In a preferred embodiment of the fifth aspect, the narrow distillate oil with a distillation range temperature below 300°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature greater than 300°C has no fluidity at the reservoir temperature .

The traditional method of obtaining quasi-components with the unit of carbon number makes the simulation research process of air injection development extremely complicated and cannot reflect the whole process of oxidation reaction, so it cannot be effectively applied to solve the problem of on-site crude oil exploitation. The present invention provides a brand new crude oil The pseudo-component acquisition method obtains four crude oil pseudo-components. The types of crude oil pseudo-components are simple and can well reflect the oxidation reaction process in air injection development. The determination of the mining method can well promote the smooth progress of on-site air injection development.

In a sixth aspect, the present invention provides a method for determining reservoirs developed by air injection based on analysis of crude oil components, wherein the method includes:

Obtain the narrow distillate group of target reservoir crude oil;

Carry out oxidation kinetics test on each narrow distillate oil in the narrow distillate oil group to determine whether the oxidation rate of each narrow distillate oil has a negative temperature coefficient interval (ie NTC interval); Fluidity test at reservoir temperature to determine whether each narrow distillate is fluid at the target reservoir temperature;

Based on whether the oxidation rate of each narrow fraction oil has a negative temperature coefficient range and whether each narrow fraction oil has fluidity at the target reservoir temperature, the first pseudo-component, the second pseudo-component, and the third pseudo-component of the target reservoir crude oil are carried out. The components and the fourth pseudo-component are determined; wherein, the first pseudo-component of crude oil is composed of narrow fractions of crude oil whose oxidation rate has a negative temperature coefficient interval and has fluidity at reservoir temperature, and the second pseudo-component of crude oil is composed of The oxidation rate does not have a negative temperature coefficient interval and is composed of various narrow fractions of crude oil that are fluid at the reservoir temperature. The crude oil is composed of various narrow fractions, and the fourth pseudo component of crude oil is composed of various narrow fractions of crude oil whose oxidation rate does not have a negative temperature coefficient range and does not have fluidity at the reservoir temperature;

When the target reservoir crude oil has the first pseudo-component and/or the third pseudo-component, the target reservoir is used as an air injection development reservoir for air injection development.

In a preferred embodiment of the sixth aspect, during the air injection development process, the crude oil oxidation process is controlled;

Further, the crude oil oxidation process is controlled by controlling the combustion temperature in the optimal combustion temperature range; further, the optimal combustion temperature is determined by the following method:

Conduct air injection development simulation experiments on target reservoirs under different combustion temperature conditions;

According to the simulation experiment results, determine the optimal combustion temperature;

Further, the control method of the oxidation process is determined by simulating and analyzing the role of each pseudo-component in the oxidation process, including:

The factors considered in the simulation analysis of the effect of the first pseudo-component on the oxidation reaction process include: ①When the heating reaches the pyrolysis temperature, this part of the component is released;

②Because the reservoir has been heated and the oxygen intake is insufficient, low-temperature oxidation will generate coke, block the pores, and affect the subsequent entry of oxygen into these pores, and when the oxygen is rich but the temperature of the reservoir is not high, the combustion is unfavorable;

③ When the oxygen intake is sufficient, the temperature rises to a certain extent so that the coke generated by this part of the oxygenation reaction can be ignited and burned;

④Under the conditions of suitable temperature and oxygen intake, whether it can enter high-temperature oxidation as soon as possible, so as to drive high-temperature oxidation of other pseudo-component crude oil in the surrounding area.

Furthermore, the factors considered in the simulation analysis of the effect of the second pseudo component on the oxidation reaction process include: ① When the heating reaches the pyrolysis temperature, the release of this part of the component;

Furthermore, the factors considered in the simulation analysis of the effect of the third pseudo-component on the oxidation reaction process include: ① Under the conditions of suitable temperature and oxygen intake, whether it can enter high-temperature oxidation as soon as possible, thereby driving other pseudo-components around High temperature oxidation of crude oil;

Furthermore, the factors considered in the simulation analysis of the influence of the fourth pseudo-component on the oxidation reaction process include: ① Under the conditions of suitable temperature and oxygen intake, high-temperature oxidation of this part of the pseudo-component crude oil occurs;

②Because the reservoir has been heated and the oxygen intake is not enough, low-temperature oxidation will generate coke, block the pores, and affect the subsequent entry of oxygen into these pores, and when the oxygen is rich but the reservoir temperature is not high, the combustion is unfavorable;

In a preferred embodiment of the sixth aspect, the distillation range temperature range of the narrow distillate oil is 25°C;

In a preferred embodiment of the sixth aspect, the narrow distillate oil with a viscosity not exceeding 500 mPa·s has fluidity at the reservoir temperature, and the narrow distillate oil with a viscosity greater than 500 mPa·s has no fluidity.

In a preferred embodiment of the sixth aspect, the narrow distillate oil with a distillation range temperature below 200°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature greater than 200°C has no fluidity at the reservoir temperature .

In a preferred embodiment of the sixth aspect, the narrow distillate oil with a distillation range temperature below 300°C has fluidity at the reservoir temperature; the narrow distillate oil with a distillation range temperature greater than 300°C has no fluidity at the reservoir temperature .

The inventor explored the oxidation kinetics characteristics of crude oil and its fractions by conducting oxidation kinetics experiments on crude oil and its fractions collected from different regions with different viscosities, and found that crude oil and its fractions were oxidized at low temperature and high temperature. Sometimes there is a negative temperature coefficient (NTC) oxidation process between them. Although the oxidation reaction rate of the fuel will decrease with the increase of temperature within a certain range of the negative temperature coefficient oxidation process, which will lead to ignition delay and other phenomena, but the negative temperature coefficient The interval of coefficient oxidation process is also the interval with oxidation reaction activity, which is helpful to promote the recovery process of crude oil so as to better realize the development of air injection. Further proper control of this process can also lead to increased production of crude oil recovery.

At present, the success rate of the implemented fire flooding development (i.e. air injection development) projects is very low. One of the reasons is the complexity of the fire flooding process itself. The fire flooding process includes a series of chemical reactions, three-phase complex migration processes and various This reaction phenomenon, there is a lack of in-depth understanding of how the combustion process works in oil reservoirs. The inventors of the present invention, based on the research on narrow fractions of crude oil, found that the NTC interval is not a disadvantageous factor in the development of air injection, but it is an active interval of oxidation activity. The whole reaction process has a significant beneficial effect, promotes the smooth progress of the air injection development, and greatly improves the success rate of the air injection development. The NTC interval in the oxidation process reaction with negative temperature coefficient between low temperature oxidation and high temperature oxidation is a key parameter to characterize the oxidation reaction activity of crude oil. Based on this, the inventor proposes the technical solution claimed in the present invention.

In the technical solution provided by the present invention, crude oil pseudo-components are constructed according to fluidity and whether there is a negative temperature coefficient (NTC) interval between the low-temperature oxidation process and the high-temperature oxidation process, and the pseudo-components combined with NTC are obtained , can well reflect the oxidation process of low temperature, high temperature and negative temperature coefficient, so that it can well reflect the whole process of oxidation reaction. In addition, the technical scheme provided by the present invention has fewer types of pseudo-components, which is convenient for further research on the matching conditions of different pseudo-components crude oil and oxidation process to obtain matching conditions with fewer relationship parameters, which helps to simplify the simulation of on-site crude oil The mathematical model of the research is used to obtain the required accurate conditions and control parameters, so as to realize the successful completion of air injection mining.

In the technical solution provided by the present invention, four pseudo-components that can represent the main oxidation reaction properties in thermochemical flooding development are obtained based on the complex crude oil mixture. The respective pseudo-components can be simulated respectively in the three oxidation processes of low temperature, negative temperature coefficient and high temperature in the development of thermochemical flooding:

(1) The four pseudo-components can simulate the low-temperature and high-temperature oxidation processes, including the generation of coke by low-temperature oxidation when the reservoir has been heated and the oxygen intake is insufficient, which blocks the pores and affects the subsequent entry of oxygen into these pores; When the layer temperature is not high, the combustion is unfavorable; when the oxygen intake is sufficient, the temperature rises to a certain extent so that the coke generated by this part of the oxygenation reaction can be ignited and burned.

(2) The pseudo-component with NTC interval can also simulate how to make better use of the negative temperature coefficient oxidation process, for example, under the action of additives, what temperature and oxygen intake can make the component promote the heavy weight of coke, coke and surrounding residues? High-temperature oxidation of high-quality fractions as soon as possible, driving other pseudo-component crude oils to undergo high-temperature oxidation;

(3) Pseudo-components without NTC interval and no fluidity can simulate the conditions of high-temperature oxidation, that is, what temperature and oxygen intake make this part of oil undergo high-temperature oxidation.

(4) The light components can also simulate thermal pyrolysis, that is, when the heating reaches the pyrolysis temperature, this part of the light components will be released.

Furthermore, the existence of pseudo-components with NTC interval can promote the whole reaction process of crude oil air injection development, promote the smooth progress of gas flooding and air injection development, and greatly improve the success rate of air injection development.

In the technical scheme of the determination method of the air injection development reservoir based on the analysis of crude oil components provided by the present invention, it is further possible to screen the air injection development reservoir based on whether the crude oil contains pseudo components in the NTC interval, and select the reservoir containing the NTC interval. The crude oil reservoirs with pseudo-components are used as air injection development reservoirs for air injection development. During the air injection development process of the target reservoir, the pseudo-components in the crude oil with the NTC range help the crude oil in the reservoir to enter the high-temperature combustion state smoothly, greatly improving the on-site crude oil recovery, and better ensuring the injection efficiency. The success of air development.

In short, the pseudo-components obtained by the crude oil pseudo-components acquisition method provided by the present invention are helpful for analysis and exploration including crude oil physical properties, reservoir physical properties, pore blockage, oxygen enrichment, and the influence of fuel and gas amount on the development effect of air injection ; When applied to the numerical simulation analysis of air injection development, it can simplify the model calculation and avoid problems such as too long numerical simulation time and poor calculation stability; it can be effectively used to solve the problem of on-site crude oil extraction in air injection development. The air injection development reservoir determination method based on the analysis of crude oil components provided by the invention is helpful to promote the smooth progress of on-site air injection development.

Description of drawings

Figure 1 shows the thermal reaction characteristics of C20 carbon alkane and dimethyl anthracene at 4.1MPa.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Apparently, the described embodiments are some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1

This embodiment provides a method for obtaining crude oil pseudo-components and the first pseudo-component, the second pseudo-component, the third pseudo-component, and the fourth pseudo-component obtained by the method.

In the present embodiment, the crude oil quasi-component acquisition method comprises:

1) Collect 1# crude oil (the viscosity of surface degassed oil is 540mPa·s), and distill 1# crude oil to obtain the narrow fraction oil group of 1# crude oil;

The distillation range temperature of each narrow distillate in the narrow distillate group is shown in Table 1;

2) Carry out oxidation kinetics test on each narrow distillate oil in the narrow distillate oil group, determine whether the oxidation rate of each narrow distillate oil has a negative temperature coefficient interval (ie NTC interval); for each narrow distillate oil in the narrow distillate oil group Carry out a fluidity test at the reservoir temperature to determine whether each narrow distillate has fluidity at the reservoir temperature (narrow distillates with a viscosity not exceeding 500mPa·s have fluidity at the reservoir temperature, and those with a viscosity greater than 500mPa·s Narrow distillates are not fluid);

Among them, the oxidation kinetics test uses a fast compressor to test narrow fractions;

See Table 1 for the results;

Table 1 Oxidation kinetics test results of 1# crude oil narrow distillate using fast compressor

Wherein the equivalence ratio refers to the ratio of the amount of air and narrow distillate;

Narrow distillate oil 1, narrow distillate oil 2, narrow distillate oil 3, and narrow distillate oil 4 have fluidity at the reservoir temperature, and narrow distillate oil 5 and narrow distillate oil 6 have no fluidity at the reservoir temperature;

3) Based on whether the oxidation rate of each narrow fraction of the target crude oil has a negative temperature coefficient range and whether each narrow fraction has fluidity at the reservoir temperature, the pseudo-component of the target crude oil is obtained;

The oxidation rate has a negative temperature coefficient range and the narrow fractions with fluidity at the reservoir temperature are mixed to form the first pseudo-component of the target crude oil; in this embodiment, it is composed of narrow fraction 1 and narrow fraction 2;

The oxidation rate does not have a negative temperature coefficient interval and the narrow fractions that have fluidity at the reservoir temperature are mixed to form the second pseudo-component of the target crude oil; in this embodiment, it is composed of narrow fractions 3 and 4;

The narrow fractions whose oxidation rate has a negative temperature coefficient range and have no fluidity at the reservoir temperature are mixed to form the third pseudo-component of the target crude oil; in this embodiment, it is composed of narrow fraction 5;

The narrow fractions whose oxidation rate does not have a negative temperature coefficient range and which do not have fluidity at the reservoir temperature mix to form the fourth pseudo-component of the target crude oil; in this embodiment, it consists of narrow fraction 6.

It can be seen from Table 1 that the reactivity of narrow distillate oils with NTC intervals has obvious advantages over the reactivity of narrow distillate oils without NTC intervals.

This embodiment also provides a method for determining reservoirs developed by air injection based on analysis of crude oil components, wherein the method includes:

Obtain the first pseudo-component, the second pseudo-component, the third pseudo-component, and the fourth pseudo-component with reference to the crude oil pseudo-component acquisition method provided in this embodiment;

The 1# crude oil contains both the first pseudo-component and the third pseudo-component, and the reservoir where the 1# crude oil is located is used as an air injection development reservoir for air injection development.

During the air injection development process of the reservoir where the 1# crude oil is located, the crude oil burns smoothly and enters the high temperature range, and the air injection development is successfully realized.

Example 2

In the present embodiment, the crude oil quasi-component acquisition method includes:

1) Collect 2# crude oil (surface degassed oil viscosity 5900mPa s), distill 2# crude oil to obtain the narrow fraction oil group of 2# crude oil;

The distillation range temperature of each narrow distillate in the narrow distillate group is shown in Table 2;

2) Carry out oxidation kinetics test on each narrow distillate oil in the narrow distillate oil group, determine whether the oxidation rate of each narrow distillate oil has a negative temperature coefficient interval (ie NTC interval); Carry out the fluidity test at the reservoir temperature to determine whether each narrow distillate has fluidity at the reservoir temperature (the narrow distillate with a viscosity not exceeding 500mPa·s at the reservoir temperature has fluidity, and the narrow distillate with a viscosity greater than 500mPa·s Narrow distillates are not fluid);

Among them, the oxidation kinetics test uses a fast compressor to test the narrow distillate oil; the results are shown in Table 2;

Table 2 Oxidation kinetics test results of 2# crude oil narrow distillate using fast compressor

Narrow distillate 1, narrow distillate 2 and narrow distillate 5 have obvious low temperature, negative temperature coefficient and high temperature three-stage oxidation characteristics, strong reactivity, and ignition delay in the range of negative temperature coefficient;

Narrow distillate oil 1 and narrow distillate oil 2 have fluidity at reservoir temperature, while narrow distillate oil 3, narrow distillate oil 4 and narrow distillate oil 5 have no fluidity at reservoir temperature;

The oxidation rate has a negative temperature coefficient interval and each narrow fraction oil with fluidity at the reservoir temperature is mixed to form the first pseudo-component of the target crude oil; in this embodiment, it is composed of narrow fraction oil 1;

The narrow fractions whose oxidation rate does not have a negative temperature coefficient range and which have fluidity at the reservoir temperature are mixed to form the second pseudo-component of the target crude oil; in this embodiment, it consists of narrow fraction 2;

The narrow fractions whose oxidation rate has a negative temperature coefficient range and have no fluidity at the reservoir temperature are mixed to form the third pseudo-component of the target crude oil; in this embodiment, it is composed of the narrow fraction 3;

The narrow fractions whose oxidation rate does not have a negative temperature coefficient range and which do not have fluidity at the reservoir temperature are mixed to form the fourth pseudo-component of the target crude oil; in this example, it is composed of narrow fractions 4 and 5.

It can be seen from Table 2 that the reactivity of narrow distillate oils with NTC intervals has obvious advantages over the reactivity of narrow distillate oils without NTC intervals.

The 2# crude oil contains both the first pseudo-component and the third pseudo-component. The reservoir where the 2# crude oil is located is used as the air injection development reservoir for conventional air injection development. air development.

During the conventional air injection development process of the reservoir where the 2# crude oil is located, the crude oil burns smoothly and enters the high temperature range, and the air injection development is successfully realized. See Table 3 for development indicators.

The oil production of Example 2 is lower than that of Example 1 during the development process of air injection. The role of each pseudo-component in the oxidation process can be further simulated and analyzed to determine the appropriate mining method to control the oxidation process and apply it to actual mining; other methods can also be used to control the oxidation process; thereby improving mining efficiency, such as Control the combustion temperature to be at the optimum combustion temperature, so as to get better mining effect.

In order to better realize the air injection development of the reservoir where the 2# crude oil is located, this embodiment provides a new method for determining the air injection development reservoir based on the analysis of crude oil components, wherein the method includes:

The simulation experiment of air injection development under different combustion temperature conditions was carried out on the reservoir where 2# crude oil is located; the results are shown in Table 4; according to the simulation experiment results, the optimal combustion temperature was determined, and the optimal combustion temperature was determined to be 450-500 °C. Not higher than 550°C;

The 2# crude oil contains both the first pseudo-component and the third pseudo-component. The reservoir where the 2# crude oil is located is used as the air injection development reservoir for air injection development with controlled combustion temperature, specifically according to the air injection volume shown in Table 3 Air injection development, during the air injection development process, the combustion temperature is maintained between 450-500 °C.

During the air injection development process with controlled combustion temperature in the reservoir where the 2# crude oil is located, the crude oil burns smoothly and enters the high temperature range, and the air injection development is successfully realized. See Table 3 for development indicators.

It can be seen from Table 3 that taking measures to control the oxidation process can significantly improve the mining effect.

Table 3 Comparison of injection and production indicators during the field test of the reservoir where 2# crude oil is located

the	常规方式的注空气开发Conventional Air Injection Development	控制燃烧温度的注空气开发Development of Air Injection for Controlling Combustion Temperature
累产油(t)Accumulated oil production (t)	28892889	68266826
平均月产油(t)Average monthly oil production (t)	412.7412.7	975.7975.7
累产液(t)Accumulated fluid (t)	3686236862	6401264012
平均月产液(t)Average monthly fluid production (t)	52665266	45724572
累注汽(t)Accumulated steam injection (t)	2319623196	3764737647
月注汽(t)Monthly steam injection (t)	33143314	26892689

The optimal combustion temperature data of table 4 embodiment 4 heavy oil

Example 3

1) Collect 3# crude oil (the viscosity of ground degassed oil is 21000mPa·s), and distill 3# crude oil to obtain the narrow fraction oil group of 1# crude oil;

The distillation range temperature of each narrow distillate in the narrow distillate group is shown in Table 3;

Among them, the oxidation kinetics test was carried out with a fast compressor and an adiabatic acceleration calorimeter;

See Table 5 for the results;

Table 5 Oxidation kinetics test results of narrow distillates of 3# crude oil using fast compressor

3# crude oil has almost no fractions below 200°C and fractions between 250°C-425°C, and there are only very small fractions in the two distillation temperature ranges of 200-225°C and 225-250°C, which can be ignored; 200-225°C fractions The oil does not have the NTC phenomenon; due to the small distillation harvest, it is impossible to judge whether there is an NTC range in the distillate oil at 225-250°C;

Due to the restriction that the distillation temperature of the experimental oil by the rapid compressor is not higher than 300°C, the 3# crude oil cannot be tested by the rapid compressor; for other narrow fractions of the 3# crude oil that cannot be tested by the rapid compressor, adiabatic acceleration is used Calorimeter (ARC) was used to test the lumped characteristics of oxidation kinetics; in order to ensure the continuity and comparability of the results, firstly, under the same temperature and pressure control conditions, the adiabatic acceleration calorimeter and The comparison experiment of the fast compressor was carried out, and the same result was obtained, which confirmed the comparability of the two experimental equipment for the crude oil experiment;

The 425-450°C distillate of 3# crude oil, the residual oil with a distillation temperature greater than 505°C, and the 3# crude oil were tested for oxidation kinetics using an adiabatic acceleration calorimeter; the 425-450°C distillate oil of 3# crude oil, with a distillation temperature greater Residual oil at 505°C and 3# crude oil both show three-stage oxidation characteristics of low temperature, negative temperature coefficient and high temperature; among them, 425-450°C distillate has low-temperature exotherm at 150-180°C, and high-temperature exotherm begins at 200°C, there is a weak ignition delay phenomenon between 180-200°C, and the continuous temperature range of the ignition delay phenomenon is narrow; the residual oil with a distillation temperature greater than 505°C reacts strongly at low temperature, and has a strong ignition delay phenomenon, and the ignition delay phenomenon occurs after 350°C. Obvious high-temperature reaction is seen; the low-temperature oxidation exotherm of 3# crude oil is at 170-230°C, but the high-temperature exotherm starts at 350°C, and the ignition delay phenomenon lasts in a wide temperature range.

The narrow fractions of oxidation rate with negative temperature coefficient range and fluidity at reservoir temperature are mixed to form the first pseudo-component of the target crude oil; there is no such component in this example.

Narrow fractions whose oxidation rates do not have a negative temperature coefficient interval and are fluid at the reservoir temperature mix to form the second pseudo-component of the target crude oil; this component is absent in this example.

The narrow fractions whose oxidation rate has a negative temperature coefficient interval and are not fluid at the reservoir temperature are mixed to form the third pseudo-component of the target crude oil; narrow fractions 1 and 2 are composed in this example.

Narrow fractions whose oxidation rates do not have a negative temperature coefficient interval and which are not fluid at reservoir temperature mix to form the fourth pseudo-component of the target crude oil; this component is absent in this example.

It can be seen from Table 3 that the reactivity of narrow distillate oils with NTC range is better.

This embodiment also provides a method for determining a production method based on analysis of crude oil components in air injection development, wherein the method includes:

The 3# crude oil only contains the third pseudo-component, and the reservoir where the 3# crude oil is located is used as an air injection development reservoir for air injection development.

During the air injection development process of the reservoir where the 3# crude oil is located, the crude oil burns smoothly and enters the high temperature range, and the air injection development is successfully realized.

The oil production in the air injection development process of Example 2 is not as good as the oil production in Example 2 when air injection production is carried out in a conventional way. The role of each pseudo-component in the oxidation process can be further simulated and analyzed to determine the appropriate mining method to control the oxidation process and apply it to actual mining; other methods can also be used to control the oxidation process; thereby improving mining efficiency, such as In the same manner as in Example 2, the combustion temperature is controlled to be at the optimum combustion temperature to carry out the oxidation reaction, so that a better mining effect can be obtained.

The embodiment of the present invention selects 1# oil, 2# oil and 3# oil, where three crude oils with NTC interval distillates are located for air injection production, and the final air injection production can be carried out smoothly, indicating that the selection of oil with NTC The air injection production of the reservoir where the crude oil of the interval distillate is located can help to ensure the smooth progress of the air development.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims

A crude oil pseudo-component, wherein the crude oil pseudo-component is formed by mixing various narrow fractions in the narrow fraction oil group of the target crude oil, whose oxidation rate has a negative temperature coefficient range and has fluidity at the reservoir temperature.
A crude oil pseudo-component, wherein the crude oil pseudo-component is formed by mixing various narrow fractions in the narrow fraction oil group of the target crude oil, whose oxidation rate does not have a negative temperature coefficient range and has fluidity at the reservoir temperature.
A crude oil pseudo-component, wherein the crude oil pseudo-component is formed by mixing various narrow fractions in the narrow fraction oil group of the target crude oil, the oxidation rate has a negative temperature coefficient range and has no fluidity at the reservoir temperature.
A crude oil pseudo-component, wherein the crude oil pseudo-component is formed by mixing various narrow fractions in the narrow fraction oil group of the target crude oil, whose oxidation rate does not have a negative temperature coefficient range and does not have fluidity at the reservoir temperature.
The crude oil quasi-component according to any one of claims 1-4, wherein,

The distillation range temperature range of the narrow distillate is 25°C;

At the reservoir temperature, the narrow distillate oil with a viscosity not exceeding 500mPa·s has fluidity, and the narrow distillate oil with a viscosity greater than 500mPa·s has no fluidity.
The method for obtaining the crude oil quasi-component described in any one of claims 1-4, wherein, the method comprises:

Obtain the narrow distillate group of the target crude oil;

Carry out oxidation kinetics test on each narrow distillate in the narrow distillate group to determine whether the oxidation rate of each narrow distillate has a negative temperature coefficient range; Performance test to determine whether each narrow distillate is fluid at the reservoir temperature;

Based on whether the oxidation rate of each narrow fraction of the target crude oil has a negative temperature coefficient range and whether each narrow fraction has fluidity at the reservoir temperature, the pseudo-component of the target crude oil is obtained; where,

The oxidation rate has a negative temperature coefficient interval and each narrow distillate oil with fluidity at the reservoir temperature is mixed to form the first pseudo-component of the target crude oil;

The oxidation rate does not have a negative temperature coefficient interval and the narrow distillates with fluidity at the reservoir temperature are mixed to form the second pseudo-component of the target crude oil;

The narrow fractions whose oxidation rate has a negative temperature coefficient interval and have no fluidity at the reservoir temperature are mixed to form the third pseudo-component of the target crude oil;

The narrow distillates whose oxidation rates do not have a negative temperature coefficient range and which do not have fluidity at the reservoir temperature mix to form the fourth pseudo-component of the target crude oil.
A method for determining reservoirs developed by air injection based on analysis of crude oil components, wherein the method includes:

Obtain the narrow distillate group of target reservoir crude oil;

Carry out oxidation kinetics tests on each narrow distillate in the narrow distillate group to determine whether the oxidation rate of each narrow distillate has a negative temperature coefficient range; Fluidity test to determine whether each narrow distillate is fluid at the target reservoir temperature;

Based on whether the oxidation rate of each narrow fraction oil has a negative temperature coefficient range and whether each narrow fraction oil has fluidity at the target reservoir temperature, the first pseudo-component, the second pseudo-component, and the third pseudo-component of the target reservoir crude oil are carried out. The components and the fourth pseudo-component are determined; wherein, the first pseudo-component of crude oil is composed of narrow fractions of crude oil whose oxidation rate has a negative temperature coefficient interval and has fluidity at reservoir temperature, and the second pseudo-component of crude oil is composed of The oxidation rate does not have a negative temperature coefficient range and is composed of narrow fractions of crude oil that are fluid at the reservoir temperature. The crude oil is composed of various narrow fractions, and the fourth pseudo component of crude oil is composed of various narrow fractions of crude oil whose oxidation rate does not have a negative temperature coefficient range and does not have fluidity at the reservoir temperature;

When the target reservoir crude oil has the first pseudo-component and/or the third pseudo-component, the target reservoir is used as an air injection development reservoir for air injection development.
The determination method according to claim 7, wherein,

The distillation range temperature range of the narrow distillate is 25°C;

At the reservoir temperature, the narrow distillate oil with a viscosity not exceeding 500mPa·s has fluidity, and the narrow distillate oil with a viscosity greater than 500mPa·s has no fluidity.
The determination method according to claim 7, wherein, during the air injection development process, the crude oil oxidation process is controlled by controlling the combustion temperature in an optimal combustion temperature range.
According to the method for determining according to claim 9, the optimum combustion temperature is determined in the following manner:

Conduct air injection development simulation experiments on target reservoirs under different combustion temperature conditions;

According to the simulation experiment results, the optimal combustion temperature is determined.