Method and device for determining hydrocarbon generation intensity of highly over-mature marine hydrocarbon source rock

Abstract

The invention provides a method and a device for determining the hydrocarbon generation intensity of high and over-mature marine hydrocarbon source rocks. The method comprises the following steps: acquiring an original logging curve of a layer section of a target development hydrocarbon source rock; obtaining organic carbon contents of hydrocarbon source rocks at different depths, and generating an organic carbon content curve of the hydrocarbon source rocks; performing multiple regression analysis on the obtained original logging curve and the hydrocarbon source rock organic carbon content curve, and selecting a target logging curve; establishing a hydrocarbon source rock organic carbon content fitting formula; constructing a hydrocarbon source rock hydrocarbon generation amount fitting formula; and obtaining a calculation formula of the hydrocarbon generation intensity of the highly over-mature marine hydrocarbon source rocks by utilizing a hydrocarbon source rock organic carbon content fitting formula, a hydrocarbon source rock hydrocarbon generation amount fitting formula, a logging data interval and the hydrocarbon source rock densities corresponding to the hydrocarbon source rock samples with different depths. A large number of core samples do not need to be collected, and the core sampling and analysis testing cost is reduced; and the corrected calculation formula utilizes an accumulation method, so that man-made interference caused when the average number of the parameters is selected is avoided, and the operability is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas accumulation, and in particular relates to a method and a device for determining the hydrocarbon generation intensity of highly over-mature marine source rocks. Background Art

[0002] Deep marine carbonate oil and gas reservoirs have great exploration potential and are an important oil and gas exploration field in my country. Efficient and accurate calculation of the hydrocarbon generation intensity of highly overmature marine source rocks is of great significance for oil and gas resource evaluation and favorable zone optimization. However, due to the deep burial and old age of highly overmature marine source rocks, it is difficult to obtain the evaluation parameters of the hydrocarbon generation potential of source rocks, so it is difficult to efficiently and accurately evaluate the hydrocarbon generation intensity of highly overmature marine source rocks. Summary of the invention

[0003] The inventors found that the current calculation of hydrocarbon generation intensity of source rocks is mainly based on the formula Q=H×C×ρ×HI, where H is the thickness of the source rock, C is the organic carbon content (TOC) of the source rock, ρ is the density of the source rock, and HI is the hydrogen index of the source rock. In the calculation process, the selection of these parameters mainly uses the average value of the target layer parameters, and the source rock is highly heterogeneous, and the hydrocarbon generation intensity result calculated by the average value of each parameter is low in accuracy and is also susceptible to human interference; on the other hand, obtaining these parameters of highly overmature marine source rocks requires a large number of samples, which takes a long time, is expensive, and has a high cost, and the hydrogen index of highly overmature marine source rocks is difficult to accurately obtain using experimental means.

[0004] In view of this, it is necessary to establish a method that can efficiently and accurately evaluate the hydrocarbon generation intensity of highly overmature marine source rocks, which can provide a basis for oil and gas resource prediction and oil and gas zone optimization, and is of great significance to oil and gas exploration.

[0005] Specifically, the method for determining the hydrocarbon generation intensity of highly overmature marine source rocks proposed in the present invention comprises the following steps:

[0006] Obtain the target layer section where source rocks are developed and obtain the original logging curve of the layer section;

[0007] Obtain the organic carbon content of source rock samples at different depths and generate a source rock organic carbon content curve;

[0008] Perform multiple regression analysis on the original well logging curve obtained and the organic carbon content curve of the source rock, and select the target well logging curve that meets the required correlation with the organic carbon content curve of the source rock;

[0009] Fitting the target logging curve with the organic carbon content of source rock samples obtained at different depths to establish a fitting formula for the organic carbon content of source rock;

[0010] Using the preset maturity of source rocks, a fitting formula for the hydrocarbon generation amount of source rocks is constructed;

[0011] Using the fitting formula of source rock organic carbon content, source rock hydrocarbon generation amount, logging data interval, and source rock density corresponding to source rock samples at different depths, the hydrocarbon generation intensity of highly overmature marine source rocks is obtained according to the following formula:

[0012] Q=∑V TOC ×H×ρ×V HI

[0013] Where Q is the hydrocarbon generation intensity of highly overmature marine source rocks, V TOC is the organic carbon content of source rock obtained by fitting formula, V HI is the hydrocarbon generation amount of source rock obtained by fitting formula of hydrocarbon generation amount of source rock, ρ is the density of source rock corresponding to source rock samples at different depths, and H is the interval of logging data.

[0014] Furthermore, the target layer section where source rocks are developed is obtained, and the original logging curve of the layer section is obtained, including:

[0015] Investigate the structure and sedimentary background of the target area, understand the development characteristics of the main lithologies in the target area, screen out the layers where source rocks are developed, and obtain the original logging curves of the layers.

[0016] Furthermore, the original logging curves at least include an acoustic wave curve, a natural gamma curve, a resistivity curve, and a density curve.

[0017] Furthermore, the target logging curve is fitted with the organic carbon content of source rock samples obtained at different depths, and a fitting formula for the organic carbon content of source rock is established, including:

[0018] The established fitting formula for the organic carbon content of source rocks is:

[0019] V TOC =ΣA i ×C i +B

[0020] Among them, V TOC is the organic carbon content of source rock samples obtained at different depths, C i is the data of the i-th target logging curve, A i is the coefficient corresponding to the i-th logging curve, and B is the calculation parameter;

[0021] The organic carbon content of source rock samples at different depths and the data of target logging curves are used to obtain the coefficients and calculation parameters corresponding to the logging curves.

[0022] Furthermore, using the preset maturity of source rocks, a fitting formula for the hydrocarbon generation amount of source rocks is constructed, including:

[0023] The fitting formula of hydrocarbon generation amount of source rock is:

[0024] V HI =α×In(Ro)+β

[0025] Where Ro is the maturity of source rock, V HI is the hydrocarbon generation amount of source rock obtained by fitting the maturity of source rock, α and β are calculation parameters, and the calculation parameters are obtained by comparing the maturity of source rock and the hydrocarbon generation amount of source rock.

[0026] Furthermore, the maturity of the source rock is obtained by experimental testing or by using depth fitting.

[0027] Furthermore, the logging curve data interval is 0.125m.

[0028] On the other hand, the present invention also proposes a device for determining the hydrocarbon generation intensity of highly over-mature marine source rocks, comprising an original logging curve acquisition module, an organic carbon content curve generation module, a target logging curve screening module, a first formula establishment module, a second formula establishment module, and a hydrocarbon generation intensity calculation module, wherein:

[0029] The original logging curve acquisition module is used to obtain the target layer section where source rocks are developed and obtain the original logging curve of the layer section;

[0030] An organic carbon content curve generation module is used to obtain the organic carbon content of source rock samples at different depths and generate a source rock organic carbon content curve;

[0031] The target logging curve screening module is used to perform a multivariate regression analysis on the original logging curve obtained and the organic carbon content curve of the source rock, and select the target logging curve whose correlation with the organic carbon content curve of the source rock meets the requirements;

[0032] The first formula establishment module is used to fit the target well logging curve with the source rock organic carbon content of the source rock samples obtained at different depths, and establish a source rock organic carbon content fitting formula;

[0033] The second formula building module is used to construct a fitting formula for hydrocarbon generation amount of source rocks using the preset maturity of source rocks;

[0034] The hydrocarbon generation intensity calculation module is used to obtain the hydrocarbon generation intensity of highly over-mature marine source rocks according to the following formula using the fitting formula of source rock organic carbon content, source rock hydrocarbon generation amount, logging data interval, and source rock density corresponding to source rock samples at different depths:

[0035] Q=∑V TOC×H×ρ×V HI

[0036] Where Q is the hydrocarbon generation intensity of highly overmature marine source rocks, V TOC is the organic carbon content of source rock obtained by fitting formula, V HI is the hydrocarbon generation amount of source rock obtained by fitting formula of hydrocarbon generation amount of source rock, ρ is the density of source rock corresponding to source rock samples at different depths, and H is the interval of logging data.

[0037] In a third aspect, an embodiment of the present invention further discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the aforementioned method for determining the hydrocarbon generation intensity of highly overmature marine source rocks.

[0038] In a fourth aspect, based on the same inventive concept, an embodiment of the present invention further provides a computer-readable storage medium, which stores the method for executing the aforementioned method for determining the hydrocarbon generation intensity of highly over-mature marine source rocks.

[0039] Based on the above technical solution, the beneficial effects of the present invention compared with the prior art are as follows:

[0040] The present invention uses the logging data of the standard developed source rock layer section, combined with the source rock organic carbon content fitting formula and the source rock hydrocarbon generation amount fitting formula established by experimental and theoretical demonstration to obtain a revised high-overmature marine source rock hydrocarbon generation intensity calculation formula. The present invention does not need to collect a large number of core samples, reducing the costs of core sampling and analysis and testing, and can be used in areas with few wells and deep layers where core samples are difficult to obtain, improving the limitations of previous methods; the revised high-overmature marine source rock hydrocarbon generation intensity calculation formula also uses the accumulation method, avoiding the human interference caused by the selection of the average number of parameters, and increasing operability. The method can be used to obtain the hydrocarbon generation intensity data of each well location, draw maps such as hydrocarbon generation intensity, and can effectively support the optimization of favorable zones and the demonstration of risk targets. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 This is a schematic flow chart of a method for determining the hydrocarbon generation intensity of highly over-mature marine source rocks in Example 1 of the present invention;

[0043] Figure 2This is a schematic diagram of fitting each original well logging curve involved in step S130 with the organic carbon content curve of the source rock in the first embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of obtaining a fitting calculation formula for source rock TOC content by fitting the natural gamma curve GR and the acoustic wave curve AC as target logging curves with the source rock organic carbon content curve in step S140 in the first embodiment of the present invention;

[0045] Figure 4 This is a schematic diagram of the experimental results showing that the hydrocarbon generation conversion rate of source rocks is in a logarithmic relationship with maturity in Example 1 of the present invention;

[0046] Figure 5 This is a schematic diagram of the structure of a device for determining the hydrocarbon generation intensity of highly over-mature marine source rocks in Example 2 of the present invention. DETAILED DESCRIPTION

[0047] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0048] Embodiment 1

[0049] The present invention proposes a method for efficiently and accurately evaluating the hydrocarbon generation intensity of highly over-mature marine source rocks, which provides a basis for oil and gas resource prediction and oil and gas zone optimization, and is of great significance to oil and gas exploration. Figure 1 As shown, the method for determining the hydrocarbon generation intensity of highly over-mature marine source rocks includes steps S110 to S160, specifically:

[0050] Step S110, obtaining a target layer segment where source rocks are developed, and obtaining an original logging curve of the layer segment.

[0051] In practical applications, we first investigate the structure and sedimentary background of the target area, understand the development characteristics of the main lithologies in the target area, screen out the layers where source rocks are developed, and obtain the acoustic wave curves, natural gamma curves, resistivity curves, density curves and other logging curves of the layers.

[0052] Step S120, obtaining the source rock organic carbon content of source rock samples at different depths, and generating a source rock organic carbon content curve.

[0053] The source rock organic carbon content (which can be recorded as TOC content) of a certain amount of source rock samples at different depths can be obtained through experimental testing to generate a source rock organic carbon content curve.

[0054] Step S130, performing a multivariate regression analysis on the original well logging curve obtained and the organic carbon content curve of the source rock, and selecting a target well logging curve that meets the required correlation with the organic carbon content curve of the source rock.

[0055] Using the logging curves obtained in step S110, a multivariate regression analysis is performed on each logging curve and the TOC content curve generated in step S120, and each logging curve is fitted with the TOC content curve to obtain the correlation between each logging curve and the TOC content curve. The logging curve with a good correlation with the TOC content curve is preferred, and the selected multiple logging curves are used as target logging curves.

[0056] In some embodiments, the well logging curves with a correlation with the TOC content curve greater than 0.5 are selected as well logging curves, such as Figure 2 In the natural gamma curve GR (correlation R 2 is 0.6464), acoustic wave curve AC (correlation R 2 is 0.6118) as the target logging curve.

[0057] Step S140, fitting the target logging curve with the source rock organic carbon content of source rock samples obtained at different depths, and establishing a source rock organic carbon content fitting formula.

[0058] Specifically, the established fitting formula for the organic carbon content of source rocks can be:

[0059] V TOC =ΣA i ×C i + B (1)

[0060] Among them, V TOC is the organic carbon content of source rock samples obtained at different depths, C i is the data of the i-th target logging curve, A i is the coefficient corresponding to the i-th logging curve, and B is the calculation parameter. The coefficient A corresponding to the logging curve can be obtained by using the organic carbon content of source rock samples at different depths and the data of the target logging curve. i , calculate parameter B.

[0061] Specifically, Figure 2 As shown, assuming that the natural gamma curve GR and the acoustic wave curve AC in the figure are taken as the target logging curves, the natural gamma curve GR and the acoustic wave curve AC are fitted with the TOC content obtained in the experiment, and combined with formula (1), the fitting calculation formula (2) of the TOC content of the source rock in the current embodiment is obtained, and then the coefficients a and b corresponding to the logging curve are calculated, and the value of the parameter c is calculated.

[0062] V TOC = a×AC + b×GR + c (2)

[0063] Wherein, AC is the acoustic wave curve data, GR is the natural gamma curve, both of which are obtained from well logging data. The fitting calculation formula for source rock TOC content obtained in this embodiment is as follows: Figure 3 , as shown in formula (3), we get a=0.0648,b=0.0155,c=4.1463:

[0064] V TOC = 0.0648×AC + 0.0155×GR - 4.1463 (3)

[0065] Step S150, constructing a fitting formula for hydrocarbon generation of source rocks using the preset maturity of source rocks.

[0066] After a large number of experimental simulations, the inventors found that the hydrocarbon generation conversion rate of source rocks is logarithmically related to maturity, so the hydrocarbon production of source rocks is logarithmically related to maturity (e.g. Figure 4 As shown in Figure 4), the maturity of source rocks can be used to fit the corresponding hydrocarbon generation amount of source rocks, and the hydrocarbon generation amount calculation formula (4) can be obtained:

[0067] V HI =α× In(Ro) +β (4)

[0068] Where Ro is the maturity of source rock, V HI The hydrocarbon generation amount of the source rock obtained by fitting the maturity of the source rock, α and β are calculation parameters, and the calculation parameters are obtained by comparing the maturity of the source rock and the hydrocarbon generation amount of the source rock. The maturity Ro of the source rock can be obtained by experimental testing or fitted using depth. The inventors found that maturity is positively correlated with depth and low temperature gradient. The geothermal gradient of a certain area can generally be queried, so the corresponding maturity can be fitted using depth.

[0069] Step S160, using the fitting formula of the organic carbon content of the source rock, the fitting formula of the hydrocarbon generation amount of the source rock, the logging data interval, and the density of the source rock corresponding to the source rock samples at different depths, the hydrocarbon generation intensity of the highly overmature marine source rock is obtained according to the following formula:

[0070] Q=∑V TOC ×H×ρ× V HI (5)

[0071] Where Q is the hydrocarbon generation intensity of highly overmature marine source rocks, V TOC is the organic carbon content of source rock obtained by fitting the organic carbon content formula (Formula (1)), V HI is the hydrocarbon generation amount of source rock obtained by fitting the hydrocarbon generation amount formula (Formula (4)), ρ is the density of source rock corresponding to source rock samples at different depths, which can be obtained from the well logging curve, and H is the interval of well logging data.

[0072] Specifically, in practical applications, the hydrocarbon generation intensity of the source rock at the corresponding depth can be calculated by first using the TOC content of the source rock obtained by formula (1) and the hydrocarbon generation amount of the source rock obtained by formula (4). The calculation formula is shown in formula (6):

[0073] Q1=V TOC ×ρ×V HI (6)

[0074] Where V TOC is the TOC content of the source rock at the corresponding depth calculated by formula (1); ρ is the density of the source rock at the corresponding depth, which can be obtained from the well logging curve in step S110; V HI is the hydrocarbon generation amount of source rock calculated by formula (2).

[0075] Considering the interval H of the logging curve data, that is, the logging data corresponding to a depth every H distance, the hydrocarbon generation intensity of the source rock at a certain depth obtained by formula (6) is accumulated, which is the hydrocarbon generation intensity of the source rock at the corresponding thickness, and the improved calculation formula for the hydrocarbon generation intensity of the high-overmature marine source rock is obtained (formula (5)). In the formula, H is the interval of the logging data, which is generally 0.125m. Using typical well data, the hydrocarbon generation intensity of the source rock can be determined according to formula (5).

[0076] The present invention uses the logging data of the standard developed source rock layer section, combined with the source rock organic carbon content fitting formula and the source rock hydrocarbon generation amount fitting formula established by experimental and theoretical demonstration to obtain a revised high-overmature marine source rock hydrocarbon generation intensity calculation formula. The present invention does not need to collect a large number of core samples, reducing the costs of core sampling and analysis and testing, and can be used in areas with few wells and deep layers where core samples are difficult to obtain, improving the limitations of previous methods; the revised high-overmature marine source rock hydrocarbon generation intensity calculation formula also uses the accumulation method, avoiding the human interference caused by the selection of the average number of parameters, and increasing operability. The method can be used to obtain the hydrocarbon generation intensity data of each well location, draw maps such as hydrocarbon generation intensity, and can effectively support the optimization of favorable zones and the demonstration of risk targets.

[0077] Embodiment 2

[0078] The present invention also proposes a device for determining the hydrocarbon generation intensity of highly over-mature marine source rocks, such as Figure 5 As shown, it includes an original logging curve acquisition module 10, an organic carbon content curve generation module 20, a target logging curve screening module 30, a first formula establishment module 40, a second formula establishment module 50, and a hydrocarbon generation intensity calculation module 60, wherein:

[0079] The original logging curve acquisition module 10 is used to acquire the target layer section where source rocks are developed and to acquire the original logging curve of the layer section.

[0080] In practical applications, we first investigate the structure and sedimentary background of the target area, understand the development characteristics of the main lithologies in the target area, screen out the layers where source rocks are developed, and obtain the acoustic wave curves, natural gamma curves, resistivity curves, density curves and other logging curves of the layers.

[0081] The organic carbon content curve generating module 20 is used to obtain the organic carbon content of source rock samples at different depths and generate a source rock organic carbon content curve.

[0082] The source rock organic carbon content (which can be recorded as TOC content) of a certain amount of source rock samples at different depths can be obtained through experimental testing to generate a source rock organic carbon content curve.

[0083] The target logging curve screening module 30 is used to perform a multivariate regression analysis on the acquired original logging curve and the organic carbon content curve of the source rock, and select a target logging curve whose correlation with the organic carbon content curve of the source rock meets the requirements.

[0084] Using the logging curve obtained in the original logging curve acquisition module 10, a multivariate regression analysis is performed on each logging curve and the TOC content curve generated by the organic carbon content curve generation module 20, and each logging curve is fitted with the TOC content curve to obtain the correlation between each logging curve and the TOC content curve. The logging curve with a good correlation with the TOC content curve is preferred, and the selected multiple logging curves are used as target logging curves.

[0085] The first formula building module 40 is used to fit the target well logging curve with the source rock organic carbon content of source rock samples obtained at different depths, and to establish a fitting formula for the source rock organic carbon content.

[0086] Specifically, the established fitting formula for the organic carbon content of source rocks can be:

[0087] V TOC =ΣA i ×C i + B (1)

[0088] Among them, V TOC is the organic carbon content of source rock samples obtained at different depths, C i is the data of the i-th target logging curve, A i is the coefficient corresponding to the i-th logging curve, and B is the calculation parameter. The coefficient A corresponding to the logging curve can be obtained by using the organic carbon content of source rock samples at different depths and the data of the target logging curve. i , calculate parameter B.

[0089] The second formula building module 50 is used to construct a fitting formula for the hydrocarbon generation amount of the source rock using the preset maturity of the source rock.

[0090] After a large number of experimental simulations, the inventors found that the hydrocarbon generation conversion rate of source rocks is logarithmically related to maturity, so the hydrocarbon production of source rocks is logarithmically related to maturity (e.g. Figure 4 As shown in Figure 4), the maturity of source rocks can be used to fit the corresponding hydrocarbon generation amount of source rocks, and the hydrocarbon generation amount calculation formula (4) can be obtained:

[0091] V HI =α× In(Ro) +β (4)

[0092] Where Ro is the maturity of source rock, V HI The hydrocarbon generation amount of the source rock obtained by fitting the maturity of the source rock, α and β are calculation parameters, and the calculation parameters are obtained by comparing the maturity of the source rock and the hydrocarbon generation amount of the source rock. The maturity Ro of the source rock can be obtained by experimental testing or fitted using depth. The inventors found that maturity is positively correlated with depth and low temperature gradient. The geothermal gradient of a certain area can generally be queried, so the corresponding maturity can be fitted using depth.

[0093] The hydrocarbon generation intensity calculation module 60 is used to obtain the hydrocarbon generation intensity of the highly over-mature marine source rock according to the following formula using the fitting formula of the organic carbon content of the source rock, the fitting formula of the hydrocarbon generation amount of the source rock, the interval of the well logging data, and the density of the source rock corresponding to the source rock samples at different depths:

[0094] Q=∑V TOC ×H×ρ× V HI (5)

[0095] Where Q is the hydrocarbon generation intensity of highly overmature marine source rocks, V TOC is the organic carbon content of source rock obtained by fitting formula, V HI is the hydrocarbon generation amount of the source rock obtained by the fitting formula of the hydrocarbon generation amount of the source rock, ρ is the density of the source rock corresponding to the source rock samples at different depths, which can be obtained from the original logging curve in the original logging curve acquisition module 10, and H is the logging data interval, which is generally 0.125m.

[0096] For a more detailed implementation of the device of the present invention, please refer to Example 1, which will not be described in detail here. The device for determining the hydrocarbon generation intensity of highly overmature marine source rocks of the present invention uses the logging data of the standard developed source rock layer section, and combines the source rock organic carbon content fitting formula and the source rock hydrocarbon generation amount fitting formula established by experimental and theoretical demonstration to obtain a revised high overmature marine source rock hydrocarbon generation intensity calculation formula. The present invention does not require the collection of a large number of core samples, reducing the costs of core sampling and analysis and testing, and can be used in areas with few wells and deep layers where core samples are difficult to obtain, improving the limitations of previous methods; the revised high overmature marine source rock hydrocarbon generation intensity calculation formula also uses the accumulation method, avoiding the human interference caused by the parameters when selecting the average, and increasing operability. The present invention can be used to obtain the hydrocarbon generation intensity data of each well location, draw maps such as hydrocarbon generation intensity, and effectively support the optimization of favorable zones and the demonstration of risk targets.

[0097] In addition, an embodiment of the present invention further discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the method for determining the hydrocarbon generation intensity of highly overmature marine source rocks as described in Embodiment 1.

[0098] Based on the same inventive concept, an embodiment of the present invention also provides a computer-readable storage medium, which stores a method for segmenting continuous data of node seismic acquisition for executing the method for determining the hydrocarbon generation intensity of highly overmature marine source rocks recorded in Example 1.

[0099] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0100] The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is encompassed in a manner similar to the term "including", as explained by "including," used as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

Claims

1. A method for determining the hydrocarbon generation intensity of highly overmature marine source rocks, characterized in that: The following steps are involved: Obtain the target layer section where source rocks are developed and obtain the original logging curve of the layer section; Obtain the organic carbon content of source rock samples at different depths and generate a source rock organic carbon content curve; Perform multiple regression analysis on the original well logging curve obtained and the organic carbon content curve of the source rock, and select the target well logging curve that meets the required correlation with the organic carbon content curve of the source rock; Fitting the target logging curve with the organic carbon content of source rock samples obtained at different depths to establish a fitting formula for the organic carbon content of source rock; Using the preset maturity of source rocks, a fitting formula for the hydrocarbon generation amount of source rocks is constructed; Using the fitting formula of source rock organic carbon content, source rock hydrocarbon generation amount, logging data interval, and source rock density corresponding to source rock samples at different depths, the hydrocarbon generation intensity of highly overmature marine source rocks is obtained according to the following formula: Q=∑V TOC ×H×ρ×HI Where Q is the hydrocarbon generation intensity of highly overmature marine source rocks, V TOC is the organic carbon content of source rock obtained by the fitting formula of organic carbon content of source rock, HI is the hydrocarbon generation amount of source rock obtained by the fitting formula of hydrocarbon generation amount of source rock, ρ is the density of source rock corresponding to source rock samples at different depths, and H is the interval of logging data.

2. The method according to claim 1, characterized in that The step of obtaining a target layer section where source rocks are developed and obtaining an original well logging curve of the layer section includes: Investigate the structure and sedimentary background of the target area, understand the development characteristics of the main lithologies in the target area, screen out the layers where source rocks are developed, and obtain the original logging curves of the layers.

3. The method according to claim 1, characterized in that The original logging curves at least include sonic curves, natural gamma curves, resistivity curves, and density curves.

4. The method according to claim 1, characterized in that The method of fitting the target logging curve with the organic carbon content of source rock samples obtained at different depths to establish a fitting formula for the organic carbon content of the source rock includes: The established fitting formula for the organic carbon content of source rocks is: V TOC =ΣA i ×C i +B Among them, V TOC is the organic carbon content of source rock samples obtained at different depths, C i is the data of the i-th target logging curve, A i is the coefficient corresponding to the i-th logging curve, and B is the calculation parameter; The organic carbon content of source rock samples at different depths and the data of target logging curves are used to obtain the coefficients and calculation parameters corresponding to the logging curves.

5. The method according to claim 1, characterized in that The method of constructing a fitting formula for hydrocarbon generation amount of source rocks by using the preset maturity of source rocks includes: The fitting formula of hydrocarbon generation amount of source rock is: HI=α×In(Ro)+β Where Ro is the maturity of source rock, HI is the hydrocarbon generation of source rock obtained by fitting the maturity of source rock, α and β are calculation parameters, and the calculation parameters are obtained by comparing the maturity of source rock and the hydrocarbon generation of source rock.

6. The method according to claim 1, characterized in that The maturity of the source rock is obtained by experimental testing or by depth fitting.

7. The method according to claim 1, characterized in that The logging curve data interval is 0.125m.

8. A device for determining the hydrocarbon generation intensity of highly overmature marine source rocks, characterized in that: It includes an original logging curve acquisition module, an organic carbon content curve generation module, a target logging curve screening module, a first formula establishment module, a second formula establishment module, and a hydrocarbon generation intensity calculation module, wherein: The original logging curve acquisition module is used to acquire the target layer segment where source rocks are developed and to acquire the original logging curve of the layer segment; The organic carbon content curve generating module is used to obtain the organic carbon content of source rock samples at different depths and generate a source rock organic carbon content curve; The target logging curve screening module is used to perform a multivariate regression analysis on the acquired original logging curve and the source rock organic carbon content curve, and select a target logging curve whose correlation with the source rock organic carbon content curve meets the requirements; The first formula establishment module is used to fit the target well logging curve with the source rock organic carbon content of the source rock samples obtained at different depths, and establish a source rock organic carbon content fitting formula; The second formula building module is used to construct a fitting formula for hydrocarbon generation amount of source rocks by using the preset maturity of source rocks; The hydrocarbon generation intensity calculation module is used to obtain the hydrocarbon generation intensity of highly overmature marine source rocks according to the following formula using the fitting formula of source rock organic carbon content, the fitting formula of source rock hydrocarbon generation amount, the logging data interval, and the source rock density corresponding to source rock samples at different depths: Q=∑V TOC ×H×ρ×HI Where Q is the hydrocarbon generation intensity of highly overmature marine source rocks, V TOC is the organic carbon content of source rock obtained by the fitting formula of organic carbon content of source rock, HI is the hydrocarbon generation amount of source rock obtained by the fitting formula of hydrocarbon generation amount of source rock, ρ is the density of source rock corresponding to source rock samples at different depths, and H is the interval of well logging data.

9. 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 computer program, the method of any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for executing the method according to any one of claims 1 to 7.

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