Method, device, medium and equipment for determining supercritical CO2 content in oil reservoir

Abstract

The invention provides a method, a device, a medium and equipment for determining the content of supercritical CO2 in an oil reservoir. The method comprises the following steps: determining neutron porosity and density porosity in a whole well section of the oil reservoir based on standardized old well logging data; fitting a first curve based on normal neutron porosity and density porosity; determining the volume content of supercritical carbon dioxide contained in the oil well, and fitting a second curve based on the slope value corresponding to each first curve and the volume content of supercritical carbon dioxide in the corresponding oil well; determining the supercritical carbon dioxide volume content of the explored oil field according to the second curve; therefore, the influence of the supercritical carbon dioxide with different contents on the neutron porosity and the density porosity is different, and the slope corresponding to the first curve and the volume content of the supercritical carbon dioxide are subjected to secondary fitting, so that the relationship among the neutron porosity, the density porosity and the volume content of the supercritical carbon dioxide can be accurately reflected; and the oil reservoir productivity is accurately predicted.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and natural gas development, and in particular to a method, device, medium and equipment for determining the supercritical CO2 content in an oil reservoir. Background Art

[0002] The pre-salt carbonate formations in a Brazilian basin have been a hotspot for global oil and gas exploration in recent years. However, the oil and gas fields discovered pre-salt contain varying degrees of carbon dioxide (CO2), which not only directly reduces the hydrocarbon fluid content in the reservoirs and the economic benefits of exploration, but also brings many difficulties and challenges to oil and gas exploration, development and production.

[0003] Calculating the volumetric content of supercritical carbon dioxide is a key technology for oil and gas exploration and development in the basin's deepwater lacustrine carbonate reservoirs. However, existing technologies are currently unable to accurately measure the supercritical carbon dioxide content in reservoirs before production, making it difficult to accurately predict reservoir productivity. Summary of the Invention

[0004] In response to the problems existing in the prior art, the embodiments of the present invention provide a method, device, medium and equipment for determining the supercritical CO2 content in an oil reservoir, so as to solve or partially solve the technical problem in the prior art that the volume content of supercritical carbon dioxide in the oil reservoir cannot be accurately determined before oil and gas exploration and development, resulting in the inability to predict the oil reservoir production capacity and thus the inability to ensure the stability of productivity.

[0005] A first aspect of the present invention provides a method for determining the supercritical CO2 content in an oil reservoir, characterized in that the method comprises:

[0006] Standardizing old well logging data from multiple oil wells in an exploration oil field, and determining the neutron porosity and density porosity of the entire well section of the reservoir based on the standardized old well logging data; when the supercritical CO2 content at different depths in the entire well section is different, the corresponding neutron porosity and density porosity will also be different;

[0007] Eliminate abnormal neutron porosity and density porosity in the oil layer to obtain normal neutron porosity and density porosity;

[0008] For each oil well, fitting a first curve based on the normal neutron porosity and density porosity to determine a slope value corresponding to each first curve; determining a volume content of supercritical carbon dioxide contained in the oil well;

[0009] Fitting a second curve based on the slope value corresponding to each of the first curves and the volume content of supercritical carbon dioxide in the corresponding oil well;

[0010] The supercritical carbon dioxide volume content of the new well in the exploration oil field is determined according to the second curve.

[0011] In the above solution, the standardized processing of old well logging data of multiple oil wells in the exploration oil field includes:

[0012] Obtaining reference density data and reference neutron data corresponding to a reservoir marker layer of a standard well; the reservoir marker layer includes a mudstone layer, a salt rock layer, or a gypsum layer;

[0013] Obtaining current density data and current neutron data of the reservoir marker layer in the old well logging data, determining a density data calibration amount based on the reference density data and the current density data, and determining a neutron data calibration amount based on the reference neutron data and the current neutron data;

[0014] The density data of the remaining intervals in the old well logging data are calibrated based on the density data calibration amount, and the neutron data of the remaining intervals in the old well logging data are calibrated based on the neutron data calibration amount.

[0015] In the above solution, the method of determining the neutron porosity of the entire well section of the reservoir based on the standardized old well logging data includes:

[0016] According to the formula Determine the formation mud content V SH ;

[0017] Obtain the neutron porosity of the pure mudstone layer in the old well logging data, according to the formula Φ N =Φ log -V SH *Φ Nsh Determine the neutron porosity Φ in the remaining interval N ;in,

[0018] The SH is the shale index, the GCUR is the regional empirical constant, and the Φ log is the neutron value of the entire well section, the Φ Nsh is the neutron porosity of the pure mudstone layer in the logging data of the old well.

[0019] In the above solution, the method of determining the density porosity in the entire well section of the reservoir based on the standardized old well logging data includes:

[0020] According to the formula Determine the density porosity Φ in the entire well section of the reservoir D ;in,

[0021] ρ b is the formation density value in the old well logging data, ρ ma is the skeleton density value in the old well logging data, and the ρ f The fluid density value in the old well logging data, the ρ shis the density of pure mudstone in the old well logging data, and V SH is the formation mud content in the logging data of the old well.

[0022] In the above solution, the method further includes:

[0023] According to the formula Determine the shale index SH; where,

[0024] The GR is the true natural gamma value of the current layer in the old well logging data. max The maximum natural gamma value is preset. min The preset minimum natural gamma value.

[0025] In the above solution, fitting a first curve based on the normal neutron porosity and density porosity includes:

[0026] For each oil well, a linear fitting is performed on the normal neutron porosity and density porosity based on a preset curve fitting function to obtain a first curve; the first curve has a linear characteristic.

[0027] In the above solution, fitting the second curve based on the slope value corresponding to each of the first curves and the volume content of supercritical carbon dioxide in the corresponding oil well includes:

[0028] Based on a preset curve fitting function, a linear fit is performed on the slope value corresponding to each of the first curves and the volume content of supercritical carbon dioxide in the corresponding oil well to obtain a second curve. The function corresponding to the second curve is: in,

[0029] described is the volume content of supercritical carbon dioxide, k is the slope of the second curve, n is a constant, and m is a constant.

[0030] A second aspect of the present invention provides an apparatus for determining the supercritical CO2 content in an oil reservoir, the apparatus comprising:

[0031] A data processing unit is used to standardize old well logging data of multiple oil wells in the exploration oil field, and determine the neutron porosity and density porosity of the entire well section of the oil reservoir based on the standardized old well logging data; when the supercritical CO2 content in the entire well section is different, the corresponding neutron porosity and density porosity will also be different; and abnormal neutron porosity and density porosity are eliminated to obtain normal neutron porosity and density porosity;

[0032] a first fitting unit configured to fit a first curve based on the normal neutron porosity and density porosity for each oil well, determine a slope value corresponding to each first curve, and determine a volume content of supercritical carbon dioxide contained in the oil well;

[0033] a second fitting unit, configured to fit a second curve based on the slope value corresponding to each of the first curves and the volume content of supercritical carbon dioxide in the corresponding oil well;

[0034] A determination unit is used to determine the supercritical carbon dioxide volume content of a new well in the exploration oil field according to the second curve.

[0035] According to a third aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the steps of any one of the methods described in the first aspect are implemented.

[0036] According to a fourth aspect of the present invention, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of any one of the methods described in the first aspect are implemented.

[0037] The present invention provides a method, device, medium and equipment for determining the supercritical CO2 content in an oil reservoir. The method comprises: standardizing old well logging data of multiple oil wells in an exploration oil field, and determining the neutron porosity and density porosity of the entire well section of the oil reservoir based on the standardized old well logging data; when the supercritical CO2 content in the entire well section is different, the corresponding neutron porosity and density porosity will also be different; eliminating abnormal neutron porosity and density porosity in the oil layer to obtain normal neutron porosity and density porosity; for each oil well, fitting a first curve based on the normal neutron porosity and density porosity, and determining the slope value corresponding to each first curve; determining the volume content of supercritical CO2 contained in the oil well, and based on each first curve, fitting a first curve based on the normal neutron porosity and density porosity to obtain a normal neutron porosity and density porosity; ... The slope value corresponding to the line is fitted to a second curve with the volume content of supercritical carbon dioxide in the corresponding oil well; the volume content of supercritical carbon dioxide in the new well of the exploration oil field is determined based on the second curve; in this way, since different contents of supercritical carbon dioxide have different effects on neutron porosity and density porosity, the present invention performs curve fitting on the corresponding relationship between the fitting curves of neutron porosity and density porosity and the supercritical carbon dioxide content, and further performs quadratic fitting on the slope corresponding to the curve and the supercritical carbon dioxide volume content, thereby accurately reflecting the relationship between neutron porosity, density porosity and supercritical carbon dioxide volume content, and then using neutron porosity and density porosity to accurately determine the volume content of supercritical carbon dioxide in the oil reservoir, and accurately predict the oil reservoir production capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be construed as limiting the present invention. The same reference numerals are used throughout the accompanying drawings to denote the same components.

[0039] In the attached figure:

[0040] Figure 1 A schematic flow chart of a method for determining supercritical carbon dioxide content in an oil reservoir according to one embodiment of the present invention is shown;

[0041] Figure 2 A schematic diagram of a first curve obtained by linearly fitting the neutron porosity and density porosity of each oil well according to one embodiment of the present invention is shown;

[0042] Figure 3 A schematic diagram of a first curve fitted based on neutron porosity and density porosity is shown according to one embodiment of the present invention when the volume content of supercritical carbon dioxide at different depths in the oil layer of the same oil well is approximately the same;

[0043] Figure 4 A schematic diagram of a first curve fitted based on neutron porosity and density porosity is shown when there is a significant difference in the volume content of supercritical carbon dioxide at different depths of the oil layer in the same oil well according to one embodiment of the present invention;

[0044] Figure 5 A schematic diagram of a second curve obtained by fitting the slope value of the first curve with the corresponding supercritical carbon dioxide volume content according to one embodiment of the present invention is shown;

[0045] Figure 6 A schematic diagram of the structure of an apparatus for determining the supercritical CO2 content in an oil reservoir according to one embodiment of the present invention is shown;

[0046] Figure 7 A first curve schematic diagram corresponding to an oil field according to an embodiment of the present invention is shown;

[0047] Figure 8 A second curve schematic diagram corresponding to an oil field according to an embodiment of the present invention is shown;

[0048] Figure 9 A first curve schematic diagram corresponding to a layer section with a depth of 5460 to 5500 meters in an oil well to be explored according to one embodiment of the present invention is shown;

[0049] Figure 10 A first curve schematic diagram corresponding to a layer section with a depth of 5500 to 5560 meters in an oil well to be explored according to one embodiment of the present invention is shown;

[0050] Figure 11 A first curve schematic diagram corresponding to a layer section with a depth of 5570 to 5660 meters in an oil well to be explored according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0051] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0052] The present invention mainly uses data from well logging, core experiments, etc. to study the effects of different supercritical carbon dioxide contents on density porosity and neutron porosity, and ultimately establishes the differential relationship between the effects of different supercritical carbon dioxide contents and density porosity and neutron porosity, and quantifies this difference, thereby quickly and accurately quantitatively calculating the supercritical carbon dioxide volume content of the oil field to be explored and developed, providing a basis for well site deployment and test layer decision-making for oil and gas exploration and development, and guiding oil and gas field exploration and development.

[0053] Among them, neutron logging records the hydrogen index, which is the hydrogen content per unit volume (1cm 3 ) to the number of hydrogen nuclei in the same volume of fresh water. Then according to the definition, the hydrogen index of a pure water layer is 1; carbon dioxide does not contain hydrogen atoms, so the hydrogen index is 0; and the hydrogen index of liquid hydrocarbons is similar to that of water, and the hydrogen index of natural gas is very low. If the depth of the formation for oil and gas exploration exceeds 5,000 meters, the formation temperature and pressure are higher than the critical temperature and critical pressure of CO2. Therefore, carbon dioxide has special physical properties in the pores of the formation rock, and its density is close to that of liquid. It can be seen that under formation conditions, oil and gas layers containing different contents of supercritical carbon dioxide have different response characteristics to density porosity and neutron porosity. Therefore, the present invention uses the difference in the relationship between the influence of different contents of supercritical carbon dioxide and density porosity and neutron porosity to provide a method for determining the content of supercritical CO2 in oil reservoirs. As Figure 1 As shown, the method mainly includes the following steps:

[0054] S110, standardizing old well logging data of multiple oil wells in the exploration oil field, and determining the neutron porosity and density porosity in the entire well section of the reservoir based on the standardized old well logging data; when the supercritical CO2 content in the entire well section is different, the corresponding neutron porosity and density porosity will also be different.

[0055] In the same exploration oil field, there are many old wells (wells that have been produced) and new wells (wells that have just started production). This embodiment uses the logging data of the old wells to determine the relationship between supercritical carbon dioxide and density porosity and neutron porosity, and thus determines the volume content of supercritical carbon dioxide in the new wells based on this relationship.

[0056] Based on this, the present invention first needs to obtain old well logging data of multiple produced oil wells in the exploration oil field. The old well logging data may be affected by multiple factors such as logging instruments, lithology, wellbore conditions, mud invasion, etc., and there will be errors, which will lead to errors in the neutron porosity and density porosity determined based on the old well logging data.

[0057] To improve the accuracy of subsequent supercritical CO2 content determination, it is necessary to standardize the old well logging data for each oil well. Neutron porosity and density porosity for the entire reservoir interval are then determined based on this standardized old well logging data. The entire reservoir interval generally includes oil layers, dry layers, and water layers. Since water layers and dry layers do not contain crude oil, after determining the neutron porosity and density porosity for the entire reservoir interval in this embodiment, only the neutron porosity and density porosity of the oil layer interval are required for subsequent processing.

[0058] Specifically, oil and water layers can be identified based on logging intersection charts, mud logging, formation pressure regression fluid density and other methods, thereby screening out the neutron porosity and density porosity corresponding to the oil layer from the neutron porosity and density porosity of the entire well section.

[0059] In one embodiment, standardization processing is performed on old well logging data of multiple oil wells in an exploration oil field, including:

[0060] Obtaining reference density data and reference neutron data corresponding to a reservoir marker layer of a standard well; the reservoir marker layer includes a mudstone layer, a salt rock layer, or a gypsum layer;

[0061] Obtaining current density data and current neutron data of the reservoir marker layer in the old well logging data, determining a density data calibration amount based on the reference density data and the current density data, and determining a neutron data calibration amount based on the reference neutron data and the current neutron data;

[0062] The density data of the remaining intervals in the old well logging data are calibrated based on the density data calibration amount, and the neutron data of the remaining intervals in the old well logging data are calibrated based on the neutron data calibration amount.

[0063] Since the materials of mudstone layers, salt rock layers or gypsum layers are relatively stable, the data measured by different instruments under different conditions are not much different. Therefore, this embodiment selects the mudstone layer, salt rock layer or gypsum layer of the standard well as the marker layer. The marker layer has a corresponding reference density data and a corresponding reference neutron data. Then, the current density data and the current neutron data in the old well logging data are obtained, and the difference between the reference density data and the current density data is used as the density data calibration amount. The density data of the remaining layer sections in the old well logging data are calibrated according to the density data calibration amount; similarly, the difference between the reference neutron data and the current neutron data is used as the neutron data calibration amount, and the density data of the remaining layer sections in the old well logging data are calibrated according to the neutron data calibration amount; so as to eliminate the deviation caused by non-geological factors such as different instruments or calibration errors.

[0064] The selection criteria for standard wells are: (1) having systematic coring data; (2) having strong regional representativeness in terms of structure, lithology, oil content, etc.; and (3) having a complete, comprehensive, and accurate logging series.

[0065] For example, assuming that the formation density of the marker layer of a standard well is 2.5, and the formation density of the corresponding layer in the old well logging data of an oil well is 2.55, then the calibration amount is -0.05.

[0066] If the fluid density value of the old well logging data in the oil layer of the oil well is A, then the fluid density value after calibration should be A-0.05.

[0067] The normalized old well log data can then be used to determine neutron porosity throughout the reservoir, including:

[0068] According to the formula Determine the formation mud content V SH ;

[0069] Obtain the neutron porosity of the pure mudstone layer in the old well logging data, according to the formula Φ N =Φ log -V SH *Φ Nsh Determine the neutron porosity Φ in the remaining interval N ;in,

[0070] The SH is the shale index, the GCUR is the regional empirical constant, which can be determined based on mining experience or fitting core data, and is not limited here. log is the neutron value of the entire well section, the Φ Nsh is the neutron porosity of pure mudstone layers in old well logging data.

[0071] The mud index SH is determined according to the following method:

[0072] According to the formula Determine the shale index SH; where,

[0073] GR is the true natural gamma value of the current layer in the old well logging data. max is the preset maximum natural gamma value, GR min The preset minimum natural gamma value.

[0074] It should be noted that the actual natural gamma values ​​corresponding to different layers of the entire oil well and different depth sections of the oil layer should be different. In the old well logging data corresponding to the entire well section, the maximum natural gamma value and the minimum natural gamma value can be found, and the corresponding mud index in each layer can be determined according to the above formula.

[0075] The neutron porosity of pure mudstone layers can be directly read from old well logging data, while the neutron porosity of other layers requires further calculation. Once the neutron porosity of the pure mudstone layer is obtained, the neutron porosity of other layers can be determined using the above formula.

[0076] After the neutron porosity is determined, the density porosity of the entire well section needs to be determined. In one embodiment, the density porosity of the entire well section of the reservoir is determined based on the standardized old well logging data, including:

[0077] According to the formula Determine the density porosity Φ in the entire well section of the reservoir D ;in,

[0078] ρ b is the formation density value in the old well logging data, ρ ma is the skeleton density value in the old well logging data, ρ f is the fluid density value in the old well logging data, ρ sh is the density of pure mudstone in the old well logging data, V SH It is the formation mud content in the logging data of old wells.

[0079] Thus, according to the above method, the neutron porosity and density porosity of the entire well section in each oil well can be determined.

[0080] S111, eliminating abnormal neutron porosity and density porosity of the oil layer to obtain normal neutron porosity and density porosity;

[0081] The oil layer may also include a tight layer, which is usually considered to be a dry layer and does not contain fluid. Therefore, the neutron porosity and density porosity corresponding to the dry layer are not helpful for determining the supercritical carbon dioxide content. Therefore, it is necessary to eliminate the abnormal neutron porosity and abnormal density porosity in the oil layer, that is, the neutron porosity and density porosity of the dry layer in the oil layer section need to be eliminated.

[0082] During the actual elimination process, a neutron porosity threshold (e.g., 5%) and a density porosity threshold (e.g., 5%) are pre-set. Neutron porosities below the neutron porosity threshold are eliminated, and the remaining neutron porosities are normal neutron porosities. Similarly, density porosities below the density porosity threshold are eliminated, and the remaining density porosities are normal density porosities.

[0083] S112, for each oil well, fitting a first curve based on the normal neutron porosity and density porosity, determining a slope value corresponding to each first curve; and determining a volume content of supercritical carbon dioxide contained in the oil well;

[0084] For each oil well, after the normal density porosity and the normal neutron porosity are determined, a first curve may be fitted based on the normal neutron porosity and density porosity, and a slope value corresponding to each first curve may be determined.

[0085] In one embodiment, fitting a first curve based on normal neutron porosity and density porosity includes:

[0086] For each oil well, a linear fitting is performed on the normal neutron porosity and density porosity based on a preset curve fitting function to obtain a first curve; the first curve has a linear characteristic.

[0087] As mentioned above, since only the oil layer contains crude oil, in fact, this embodiment only performs curve fitting on the normal neutron porosity and density porosity in the oil layer. Then, for each oil well, the curve fitting function can be used to fit the neutron porosity and density porosity at different depths of the oil layer to obtain the first curve y=k i x; where y is the neutron porosity, x is the density porosity, i is the well number, k is the i is the slope value corresponding to the first curve.

[0088] Among them, the first curve of each oil well can be referred to Figure 2 , Figure 2 The first curves corresponding to multiple oil wells are shown, which are y=k1x, y=k2x, y=k3x, y=k4x, y=k5x, y=k6x, y=k7x, y=k8x, and y=k9x.

[0089] It should be noted that, generally speaking, if the volume content of supercritical carbon dioxide at different depths in the oil layer of the same oil well is roughly the same, then the neutron porosity and density porosity of the oil well are only fitted into a first curve, such as Figure 3 However, if the volume content of supercritical carbon dioxide at different depths in the oil layer of the same oil well is quite different, two first curves may be fitted, such as Figure 4 shown.

[0090] In order to intuitively see the relationship between the volume content of supercritical carbon dioxide contained in the oil well and the slope value of the first curve, it is necessary to further determine the volume content of supercritical carbon dioxide contained in the oil well and create an intersection relationship between the slope value of the first curve and the corresponding volume content of supercritical carbon dioxide.

[0091] It should be noted that after the production of old wells, crude oil samples can be obtained and analyzed to obtain the supercritical CO2 volume content corresponding to each produced oil well. Thus, for each oil well, after the first curve between the supercritical CO2 volume content, neutron porosity, and density porosity is determined, an intersection relationship between the first curve and the corresponding supercritical CO2 volume content can be established.

[0092] The intersection relationship is essentially used to characterize the relationship between the slope value of the first curve and the volume content of supercritical carbon dioxide. The intersection relationship can be presented in the form of a table, a document or a chart, which is not limited here.

[0093] For example, if it is presented in the form of a plate, you can Figure 2 The corresponding supercritical carbon dioxide volume content is added to the first curve in FIG. For the first curve with a slope value of k1, the corresponding supercritical carbon dioxide volume content is V1.

[0094] When presented in a table format, the first curve and the corresponding supercritical carbon dioxide volume content may be arranged in pairs in the table.

[0095] Since supercritical carbon dioxide has a smaller effect on density porosity but a greater effect on neutron porosity, and the higher the carbon dioxide content, the smaller the neutron porosity and the smaller the slope value. That is, if k1>k2>k3>...k i , then V1 <V2<……Vi。

[0096] S113, fitting a second curve based on the slope value corresponding to each of the first curves and the volume content of supercritical carbon dioxide in the corresponding oil well;

[0097] Once the intersection relationship between the first curve and the corresponding supercritical carbon dioxide volume content is determined, the supercritical carbon dioxide volume content of the new well in the exploration oil field can actually be determined based on the intersection relationship. However, only an approximate range can be determined, and the supercritical carbon dioxide volume content cannot be quantitatively determined.

[0098] For example, assuming that the slope value of the first curve corresponding to the density porosity and neutron porosity of the new well in the exploration oil field is determined to be between k2 and k3, then it means that the critical volume content of carbon dioxide contained in the new well in the exploration oil field is between V2 and V3.

[0099] Therefore, in order to accurately and quantitatively determine the volumetric content of supercritical carbon dioxide in the exploration oil field, it is necessary to fit a second curve based on the slope of the first curve and the volumetric content of supercritical carbon dioxide in the corresponding oil well. The second curve can represent the relationship between the slope of the first curve and the volumetric content of supercritical carbon dioxide.

[0100] Specifically, for example, the volume content of supercritical carbon dioxide corresponding to k1 is V1, the volume content of supercritical carbon dioxide corresponding to k2 is V2, and k i The corresponding supercritical carbon dioxide volume content is Vi, then the slope value k of the first curve can be i The second curve is fitted with the corresponding supercritical carbon dioxide volume content Vi, and the second curve also has a linear relationship. As the volume content of dissolved carbon dioxide in the liquid hydrocarbon increases, the slope value of the second curve gradually decreases.

[0101] In one embodiment, fitting the second curve based on the slope value corresponding to each first curve and the volume content of supercritical carbon dioxide in the corresponding oil well includes:

[0102] Based on a preset curve fitting function, a linear fit is performed on the slope value corresponding to each first curve and the volume content of supercritical carbon dioxide in the corresponding oil well to obtain a second curve. The function corresponding to the second curve is:

[0103] in,

[0104] is the volume content of supercritical carbon dioxide, K is the slope of the second curve, n is a constant, and m is a constant.

[0105] For example, assuming that the slope value of the first curve corresponding to the above multiple oil wells and the volume content of supercritical carbon dioxide are used for fitting, the second curve obtained can be referred to as Figure 5 .

[0106] S114: Determine the supercritical carbon dioxide volume content of the new well in the exploration oil field according to the second curve.

[0107] After the function corresponding to the second curve is determined, when it is necessary to measure the volume content of supercritical carbon dioxide contained in a new well in the same exploration oil field, it is only necessary to determine the corresponding slope value of the first curve based on the logging data of the new well, and then quantitatively determine the volume content of supercritical carbon dioxide in the oil field to be explored based on the slope value of the first curve and the function corresponding to the above-mentioned second curve.

[0108] For example, assuming that the slope of the first curve corresponding to the density porosity and neutron porosity of a new well in an exploration oil field is determined to be 90, 90 can be substituted into the function corresponding to the second curve to obtain a corresponding supercritical carbon dioxide volume content.

[0109] The present invention performs curve fitting on the corresponding relationship between the fitting curves of neutron porosity and density porosity and the supercritical carbon dioxide content, and further performs quadratic fitting on the slope corresponding to the curve and the supercritical carbon dioxide volume content, thereby accurately reflecting the relationship between neutron porosity, density porosity and supercritical carbon dioxide volume content. Furthermore, neutron porosity and density porosity can be used to accurately determine the supercritical carbon dioxide volume content in new wells in the oil field and accurately predict the oil reservoir production capacity.

[0110] Based on the same inventive concept as in the above embodiment, this embodiment also provides a device for determining the supercritical CO2 content in an oil reservoir, such as Figure 6 As shown, the device includes:

[0111] The data processing unit 61 is used to standardize the old well logging data of multiple oil wells in the exploration oil field, and determine the neutron porosity and density porosity of the entire well section of the oil reservoir based on the standardized old well logging data; when the supercritical CO2 content at different depths in the entire well section is different, the corresponding neutron porosity and density porosity will also be different; and the abnormal neutron porosity and density porosity in the oil layer are eliminated to obtain normal neutron porosity and density porosity;

[0112] A first fitting unit 62 is configured to fit a first curve based on the normal neutron porosity and density porosity for each oil well, determine a slope value corresponding to each first curve, and determine a volume content of supercritical carbon dioxide contained in the oil well;

[0113] A second fitting unit 63 is configured to fit a second curve based on the slope value corresponding to each of the first curves and the volume content of supercritical carbon dioxide in the corresponding oil well;

[0114] The determination unit 64 is configured to determine the volume content of supercritical carbon dioxide in the new well of the exploration oil field according to the second curve.

[0115] Since the apparatus described in the embodiments of the present invention is used to implement the method for determining the supercritical CO2 content in an oil reservoir according to the embodiments of the present invention, the specific structure and variations of the apparatus are readily apparent to those skilled in the art based on the methods described in the embodiments of the present invention, and therefore, a detailed description thereof will not be given here. All apparatuses used in the methods according to the embodiments of the present invention fall within the scope of protection of the present invention.

[0116] In practical applications, when the method and apparatus provided in the above embodiment are used to determine the volume content of supercritical carbon dioxide in an oil field, the following is achieved:

[0117] First, the logging data is standardized, and then the neutron porosity and density porosity values ​​of the entire well section are calculated, and the neutron porosity and density porosity values ​​lower than 0.05 are eliminated. Then, the first curve is fitted based on the normal neutron porosity and density porosity. Figure 7 shown.

[0118] exist Figure 7 In the figure, it can be seen that the slope value of the first curve and the corresponding supercritical carbon dioxide volume content are, for example, k1 is 1.23, and the corresponding V1 is less than 5%; k2 is 0.95, and the corresponding V2 is 12%; k3 is 0.8275, and the corresponding V3 is 25%; k4 is 0.779, and the corresponding V4 is 42.5%; k5 is 0.661, and the corresponding V5 is 45%; k6 is 0.586, and the corresponding V6 is 60%; k7 is 0.427, and the corresponding V7 is 67%; k8 is 0.279, and the corresponding V8 is 76.5%; k9 is -0.067, and the corresponding V9 is greater than 95%.

[0119] Then, the slope value of the first curve and the corresponding supercritical carbon dioxide volume content are subjected to curve fitting to obtain the second curve, such as Figure 8 shown. Figure 8 The function corresponding to the second curve in is:

[0120]

[0121] When using the second curve to determine the volume content of supercritical carbon dioxide in an oil well to be explored in a basin, refer to Figures 9 to 11 , the first curve corresponding to the depth section of 5460-5500 meters in the oil well to be explored is determined to be: y=0.7383x+0.0396;

[0122] The first curve corresponding to the depth range of 5500-5560 meters is:

[0123] y=0.7482x+0.0471;

[0124] The first curve corresponding to the depth range of 5570-5660 meters is:

[0125] y=0.7168x+0.0165.

[0126] Among them, the slope value of the first curve corresponding to the depth section of 5460 to 5500 meters is 0.7383. Substituting this slope value into the function corresponding to the second curve, it can be obtained that the volume content of supercritical carbon dioxide is 46.5%. Later, through sampling analysis during mining, it was determined that the volume content of supercritical carbon dioxide in this depth section was 44%.

[0127] The slope value of the first curve corresponding to the depth section of 5500 to 5560 meters is 0.7482. Substituting this slope value into the function corresponding to the second curve, it can be obtained that the volume content of supercritical carbon dioxide is 45.755%. Later, during mining, sampling analysis determined that the volume content of supercritical carbon dioxide in this depth section was 44%.

[0128] The slope value of the first curve corresponding to the depth section of 5570 to 5660 meters is 0.7168. Substituting this slope value into the function corresponding to the second curve, it can be obtained that the volume content of supercritical carbon dioxide is 47.98%. Later, during mining, sampling analysis determined that the volume content of supercritical carbon dioxide in this depth section was 45%.

[0129] It can be seen that when the method of the present invention is used to determine the volume content of supercritical carbon dioxide, the test error is less than 5%, and the accuracy is relatively high.

[0130] Based on the same inventive concept, this embodiment provides a computer device, as shown in the figure, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, any step of the method described above is implemented.

[0131] Based on the same inventive concept, this embodiment provides a computer-readable storage medium, as shown in the figure, which stores a computer program. When the computer program is executed by a processor, it implements the steps of any of the methods described above.

[0132] Through one or more embodiments of the present invention, the present invention has the following beneficial effects or advantages:

[0133] The present invention provides a method, device, medium and equipment for determining the supercritical CO2 content in an oil reservoir. The method comprises: standardizing old well logging data of multiple oil wells in an exploration oil field, and determining the neutron porosity and density porosity of the entire well section of the oil reservoir based on the standardized old well logging data; when the supercritical CO2 content at each depth in the entire well section is different, the corresponding neutron porosity and density porosity will also be different; eliminating abnormal neutron porosity and density porosity of the oil layer to obtain normal neutron porosity and density porosity; for each oil well, fitting a first curve based on the normal neutron porosity and density porosity to determine the slope value corresponding to each first curve; determining the volume content of supercritical carbon dioxide contained in the oil well; and calculating the slope value of each first curve based on the slope of each first curve. The slope value corresponding to the line is fitted to a second curve with the volume content of supercritical carbon dioxide in the corresponding oil well; the volume content of supercritical carbon dioxide in the new well of the exploration oil field is determined based on the second curve; in this way, since different contents of supercritical carbon dioxide have different effects on neutron porosity and density porosity, the present invention performs curve fitting on the corresponding relationship between the fitting curves of neutron porosity and density porosity and the supercritical carbon dioxide content, and further performs quadratic fitting on the slope corresponding to the curve and the volume content of supercritical carbon dioxide, thereby accurately reflecting the relationship between neutron porosity, density porosity and supercritical carbon dioxide volume content, and then using neutron porosity and density porosity to accurately determine the volume content of supercritical carbon dioxide in the new well of the oil reservoir, and accurately predict the oil reservoir production capacity.

[0134] The algorithm and display provided herein are not inherently related to any particular computer, virtual system or other device. Various general-purpose systems can also be used together with the teachings based on this. According to the above description, it is obvious that the structure required for constructing this type of system. In addition, the present invention is not directed to any specific programming language. It should be understood that various programming languages ​​can be utilized to realize the content of the present invention described herein, and the above description of specific languages ​​is for the purpose of disclosing the best mode of the present invention.

[0135] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0136] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the claims below, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Accordingly, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of the invention.

[0137] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and in addition may be divided into multiple submodules or subunits or subcomponents. All features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed herein may be combined in any combination, except that at least some of such features and / or processes or units are mutually exclusive. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature providing the same, equivalent or similar purpose.

[0138] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not other features, combinations of features from different embodiments are intended to be within the scope of the present invention and to form different embodiments. For example, in the claims below, any of the claimed embodiments may be used in any combination.

[0139] The various component embodiments of the present invention can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) can be used in practice to implement some or all of the functions of some or all of the components in the gateway, proxy server, or system according to an embodiment of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program implementing the present invention can be stored on a computer-readable medium, or can have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0140] It should be noted that the above embodiments illustrate rather than limit the invention, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between brackets should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising several different elements and by means of appropriately programmed computers. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

[0141] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0142] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for determining the supercritical CO2 content in an oil reservoir, characterized in that: The method comprises: Standardize the old well logging data of multiple oil wells in the exploration oil field, and determine the neutron porosity and density porosity of the entire well section of the reservoir based on the standardized old well logging data; when the supercritical CO2 content at each depth in the entire well section is different, the corresponding neutron porosity and density porosity will also be different; Eliminate abnormal neutron porosity and density porosity in the oil layer to obtain normal neutron porosity and density porosity; For each oil well, fitting a first curve based on the normal neutron porosity and density porosity to determine the slope value corresponding to each first curve; and determining the volume content of supercritical carbon dioxide contained in the oil well; Fitting a second curve based on the slope value corresponding to each of the first curves and the volume content of supercritical carbon dioxide in the corresponding oil well; The supercritical carbon dioxide volume content of the new well in the exploration oil field is determined according to the second curve.

2. The method according to claim 1, characterized in that The standardized processing of old well logging data of multiple oil wells in the exploration oil field includes: Obtaining reference density data and reference neutron data corresponding to a reservoir marker layer of a standard well; the reservoir marker layer includes a mudstone layer, a salt rock layer or a gypsum layer; Acquire current density data and current neutron data of the reservoir marker layer in the old well logging data, determine a density data calibration amount based on the reference density data and the current density data, and determine a neutron data calibration amount based on the reference neutron data and the current neutron data; The density data of the remaining layers in the old well logging data are calibrated based on the density data calibration amount, and the neutron data of the remaining layers in the old well logging data are calibrated based on the neutron data calibration amount.

3. The method according to claim 1, characterized in that The method of determining the neutron porosity of the entire well section of the reservoir based on the standardized old well logging data comprises: According to the formula Determine the formation mud content V SH ; Obtain the neutron porosity in the pure mudstone layer from the old well logging data, according to the formula Φ N =Φ log -V SH *Φ Nsh Determine the neutron porosity Φ in the remaining interval N ;in, SH is the shale index, GCUR is the regional empirical constant, and Φ log is the neutron value in the whole well section, the Φ Nsh It is the neutron porosity of the pure mudstone layer in the logging data of the old well.

4. The method according to claim 1, characterized in that The method of determining the density porosity of the entire well section of the reservoir based on the standardized old well logging data includes: According to the formula Determine the density porosity Φ in the entire well section of the reservoir D ; where ρ b is the formation density value in the logging data of the old well, ρ ma is the skeleton density value in the old well logging data, and the ρ f The fluid density value in the old well logging data, the ρ sh is the density value of pure mudstone in the old well logging data, and V SH is the formation mud content in the logging data of the old well.

5. The method according to claim 3, characterized in that The method further comprises: According to the formula Determine the shale index SH; where, The GR is the true natural gamma value of the current layer in the old well logging data. max The maximum natural gamma value is preset. min The preset minimum natural gamma value.

6. The method according to claim 1, characterized in that The fitting of a first curve based on the normal neutron porosity and density porosity comprises: For each oil well, a linear fit is performed on the normal neutron porosity and density porosity based on a preset curve fitting function to obtain a first curve; the first curve has a linear characteristic.

7. The method according to claim 1, characterized in that Fitting a second curve based on the slope value corresponding to each of the first curves and the supercritical carbon dioxide volume content in the corresponding oil well includes: Based on a preset curve fitting function, a linear fit is performed on the slope value corresponding to each of the first curves and the volume content of supercritical carbon dioxide in the corresponding oil well to obtain a second curve. The function corresponding to the second curve is: in, Said is the volume content of supercritical carbon dioxide, k is the slope of the second curve, n is a constant, and m is a constant.

8. A device for determining the supercritical CO2 content in an oil reservoir, characterized in that: The device comprises: The data processing unit is used to standardize the old well logging data of multiple oil wells in the exploration oil field, and determine the neutron porosity and density porosity of the entire well section of the oil reservoir based on the standardized old well logging data; when the supercritical CO2 content at each depth in the entire well section is different, the corresponding neutron porosity and density porosity will also be different; eliminate the abnormal neutron porosity and density porosity in the oil layer to obtain normal neutron porosity and density porosity; A first fitting unit is used for fitting a first curve based on the normal neutron porosity and density porosity for each oil well, and determining a slope value corresponding to each first curve; and determining a volume content of supercritical carbon dioxide contained in the oil well; A second fitting unit, configured to fit a second curve based on the slope value corresponding to each of the first curves and the volume content of supercritical carbon dioxide in the corresponding oil well; A determination unit is used to determine the volume content of supercritical carbon dioxide in a new well of the exploration oil field according to the second curve.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method according to any one of claims 1 to 7 are implemented.

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