Correction method based on the influence of dissolved alteration reservoir on volcanic rock reserve calculation

Abstract

The present invention provides a method for correcting the influence of dissolution-altered reservoirs on the calculation of volcanic rock reserves. The method comprises: step 1, using core thin section analysis and other relevant data to determine the alteration mechanism and analyze the dissolution-altered characteristics; step 2, using core calibration logging to determine the logging response characteristics of invalid reservoirs due to alteration; step 3, using a reserve calculation method to determine the total reservoir reserves and the invalid reservoir reserves; step 4, determining the final volcanic rock reserves as the reserves after deducting the invalid reservoir reserves. The method for correcting the influence of dissolution-altered reservoirs on the calculation of volcanic rock reserves classifies reservoir types during the calculation process. Due to the particularity of the alteration characteristics of volcanic rock reservoirs, it is very important to consider the influence of dissolution-altered reservoir reserves, which solves the problem of the accuracy of the calculation of the total reservoir reserves of volcanic rock reservoirs due to dissolution-altered reservoirs.

Description

Technical Field

[0001] The invention relates to the field of oil and gas field exploration and development, and in particular to a method for correcting the influence of dissolved altered reservoirs on volcanic rock reserve calculation. Background Art

[0002] Volcanic oil and gas reservoirs are one of the hottest exploration and development targets at home and abroad. They have large reserves, considerable single-well production, and good exploration and development value. With the continuous increase in the world's demand for oil and gas resources, volcanic oil and gas reservoirs are receiving more and more attention. Due to the nature of magma, different eruption modes, and the influence of later tectonic diagenesis, the lithology and lithofacies of this type of reservoir are complex and diverse, with large vertical and horizontal changes, and the lithology identification is relatively complex, so the impact on reservoir reserves is also more prominent. Volcanic rock alteration causes a great change in the pore structure of the reservoir. According to the mechanism analysis, the well logging characteristic values ​​of unaltered or lightly altered volcanic rocks are different, and the influence of alteration on reservoir reserve calculation is not considered. In order to better cope with the exploration and development of volcanic oil and gas reservoirs, it is necessary to establish an effective and applicable volcanic reservoir reserve calculation method as soon as possible. Therefore, the invalid reservoir reserves formed by alteration are corrected from the final reserves, which is of great significance for the calculation of volcanic rock reserves and later exploration and development.

[0003] At present, there are two main methods for calculating oil and gas reserves: static method and dynamic method. For producing wells, the production data of the wells can be used for calculation. The main calculation methods are production decline method, material balance method and numerical simulation method.

[0004] In the Chinese patent application with application number: CN201410604885.6, a method for predicting the productivity of volcanic rock reservoirs is involved, which is carried out in the following steps: the first step is to collect basic parameters of the reservoir itself or the reservoir of similar reservoirs in the target block that has been tested, including single well productivity Q, perforated reservoir thickness h, crude oil volume coefficient B0, comprehensive skin coefficient s, perforation yield ratio PR, start-up pressure gradient λ, post-pressure test well permeability Ks, formation pressure pe, flow pressure pw, wellbore radius rw, fluid viscosity u, and fracture length, among which the unit of post-pressure test well permeability Ks is mD, the unit of formation pressure Pe and flow pressure Pw is MPa, the unit of wellbore radius rw is m, and the unit of fluid viscosity u is MPa·s.

[0005] In the Chinese patent application with application number: CN201811109629.4, a method for calculating the geothermal energy reserves of carbonate karst pores is involved, including: a first step of acquiring seismic wave data, processing the seismic wave data, and obtaining the location information of the geothermal energy reservoir as the first information; a second step of acquiring the information of the drilling well connected to the geothermal energy reservoir as the second information; a third step of acquiring the top and bottom boundary information of the carbonate karst pores as the third information based on the first information and the second information; a fourth step of deriving the volume of the carbonate karst pores based on the third information, and then deriving the geothermal reserves of the carbonate karst pores.

[0006] In the Chinese patent application with application number: CN201810227814.7, a quantitative characterization method for fault-karst type oil reservoirs is involved, including: establishing a development model of fault-karst bodies; conducting seismic prediction of fault-karst characteristics based on the fault-karst body development model; establishing a three-dimensional geological model of fault-karst oil reservoirs based on the karst development model; and correcting the three-dimensional geological model of fault-karst oil reservoirs based on production dynamic data.

[0007] The above existing technologies are greatly different from the present invention and fail to solve the technical problem we want to solve. Therefore, we have invented a new correction method based on the influence of dissolved altered reservoirs on volcanic rock reserve calculation. Summary of the invention

[0008] The purpose of the present invention is to provide a method for correcting the influence of dissolution and alteration reservoirs on volcanic rock reserve calculation, which solves the problem of accuracy of total reserve calculation of volcanic rock reservoirs due to dissolution and alteration reservoirs.

[0009] The object of the present invention can be achieved by the following technical measures: a method for correcting the influence of dissolution-altered reservoirs on the calculation of volcanic rock reserves, the method for correcting the influence of dissolution-altered reservoirs on the calculation of volcanic rock reserves comprising:

[0010] Step 1: Use core thin section analysis and other relevant data to determine the alteration mechanism and analyze the characteristics of dissolution alteration;

[0011] Step 2, using core calibration logging to determine the logging response characteristics of the invalid reservoir due to alteration;

[0012] Step 3, determining the total reservoir reserves and the ineffective reservoir reserves by using the reserve calculation method;

[0013] Step 4: Determine the final volcanic rock reserves as the reserves after deducting the invalid reservoir reserves.

[0014] The purpose of the present invention can also be achieved by the following technical measures:

[0015] In step 1, according to the influence of dissolution and alteration on the reservoir, the characteristics of dissolution and alteration are analyzed by core thin section analysis and other relevant data. Alteration plays an important role in controlling the formation of volcanic rock reservoirs.

[0016] In step 1, the control effect of alteration on the formation of volcanic rock reservoirs is manifested as follows: devitrification and dissolution will produce secondary pores such as intercrystalline pores and dissolution pores, which are easy to form favorable reservoirs; conversely, the secondary minerals produced by alteration will fill the reservoir pores and cracks, reduce the effectiveness of the reservoir pores, and fill the reservoir space with the secondary minerals produced by alteration, forming an invalid reservoir.

[0017] In step 2, based on the identification of the alteration characteristics, the response characteristics of the invalid reservoir and the effective reservoir of clay-altered alteration on conventional logging are further determined. The clay produced by the alteration often contains a large amount of crystalline water, which fills the pores and cracks of the rock, resulting in an increase in the neutron logging value, a decrease in the density logging value, and a decrease in the resistivity, showing good reservoir characteristics, but the actual seepage characteristics are poor, and it is a non-reservoir or a poor reservoir. Intermediate-basic volcanic rocks are more susceptible to alteration, and primary pores are easily filled; the alteration characteristic sensitive logging curve is selected to compensate for the neutron and deep lateral resistivity.

[0018] In step 2, the compensation neutron greater than 31% and the deep lateral resistivity less than 10Ω·m are used as the limits of the sensitive parameters of the well logging curve of clay alteration characteristics. The sensitive parameters are used to establish the identification indicator factors of invalid reservoirs and effective reservoirs caused by alteration. When the index factor is greater than 31, it is an invalid reservoir, and when it is less than 31, it is an effective reservoir:

[0019]

[0020] Where: CNL is compensated neutron logging, %; R D is the deep lateral resistivity log, Ω·m.

[0021] In step 3, the total reserves of the reservoir and the reserves of the invalid reservoir are calculated respectively by using the logging response characteristics of the invalid reservoir due to alteration and the valid reservoir without alteration.

[0022] In step 3, the total reservoir reserves and the invalid reservoir reserves are calculated using a reserve calculation method based on the identified invalid reservoirs and valid reservoirs.

[0023] In step 3, the calculation formulas for the total volume of crude oil geological reserves and the volume of crude oil altered reservoir geological reserves are:

[0024]

[0025]

[0026] Where: N 总- Total geological reserves of crude oil by volume, 10 4 m 3 ; N 蚀变 -Oil volume alteration reservoir geological reserves, 10 4 m 3 ; B oi -Crude oil volume coefficient; A-Oil-bearing area, km 3 ;H 总 -Total effective thickness of reservoir, m; H 蚀变 -Effective thickness of altered reservoir, m; Φ e- Effective porosity, decimal; So-oil saturation, decimal.

[0027] In step 4, the reserves of the target wells in the target area are calculated according to the reserves calculation method, and then the reserves of the invalid reservoirs are calculated. Finally, the reserves of the altered invalid reservoirs are deducted to obtain the final result reserves.

[0028] In step 4, determine the final volcanic rock reserves N 最终 The formula is:

[0029] N 最终 =N 总 -N 蚀变

[0030] Where: N 总 - Total geological reserves of crude oil by volume, 10 4 m 3 ; N 蚀变 -Oil volume alteration reservoir geological reserves, 10 4 m 3 .

[0031] The correction method based on the influence of dissolution-altered reservoirs on the calculation of volcanic rock reserves in the present invention starts with the alteration mechanism of volcanic rocks, analyzes the influence of alteration on reservoirs, and then establishes alteration-only indicator factors to divide altered reservoirs based on actual analysis data. The influence on the result of effective reserves of volcanic rocks due to the reserves caused by invalid reservoirs caused by dissolution-altered reservoirs is involved. The existing reserve calculation method does not consider the influence of dissolution-altered reservoirs on reserve calculation, and the reservoir types are not classified during the calculation process. Due to the particularity of the alteration characteristics of volcanic rock reservoirs, it is very important to consider the influence of dissolution-altered reservoir reserves. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a flow chart of a specific embodiment of the method for correcting the influence of dissolved altered reservoir on volcanic rock reserve calculation according to the present invention;

[0033] Figure 2 is an alteration characteristic diagram for analyzing different core slices in a specific embodiment of the present invention;

[0034] Figure 3 The conventional well logging and nuclear magnetic well logging diagrams of the 1070m-1170m interval of the volcanic reservoir of Well X4 in a specific embodiment of the present invention;

[0035] Figure 4 It is a schematic diagram of the alteration characteristics of the volcanic rock reservoir in a certain oil field and the well-connected profile of the top interface of the oil and gas layer in a specific embodiment of the present invention.

[0036] Figure 5 The conventional logging and nuclear magnetic logging diagrams of the 1410m-1510m interval of the volcanic reservoir of Well X3 in a specific embodiment of the present invention;

[0037] Figure 6 The conventional logging and nuclear magnetic logging diagrams of the 1030m-1130m interval of the volcanic reservoir in Well X6 in a specific embodiment of the present invention are shown. DETAILED DESCRIPTION

[0038] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0039] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations and / or combinations thereof.

[0040] like Figure 1 As shown, Figure 1 The present invention is a flow chart of a method for correcting the influence of dissolved altered reservoirs on volcanic rock reserve calculation.

[0041] Step 1: Based on the results of the influence of dissolution and alteration on the reservoir, the characteristics of dissolution and alteration are analyzed by core thin section analysis and other relevant data. Alteration has an important controlling effect on the formation of volcanic rock reservoirs, which is mainly manifested as follows: devitrification and dissolution will produce secondary pores such as intercrystalline pores and dissolution pores, which are easy to form favorable reservoirs; on the contrary, the secondary minerals produced by alteration will fill the reservoir pores and cracks, reducing the effectiveness of the reservoir pores. What is mentioned here is that the secondary minerals produced by alteration fill the reservoir space and form an invalid reservoir;

[0042] Step 2: According to the identification of the above-mentioned alteration characteristics, the response characteristics of the invalid reservoir and the effective reservoir of clay-induced alteration on conventional logging are further determined. The clay produced by alteration often contains a large amount of crystal water, which is filled in the pores and cracks of the rock, resulting in an increase in the neutron logging value, a decrease in the density logging value, and a decrease in the resistivity, showing good reservoir characteristics, but the actual seepage characteristics are poor, and it is a non-reservoir or a poor reservoir. Generally, intermediate-basic volcanic rocks are more susceptible to alteration, and primary pores are easily filled; then, the compensation neutron and deep lateral resistivity of the alteration characteristic sensitive logging curve are selected. Through research and analysis, the compensation neutron greater than 31% and the deep lateral resistivity less than 10Ω·m are used as the boundaries of the sensitive parameters of the logging curve of clay-induced alteration characteristics. The sensitive parameters are used to establish the identification indicator factors of the invalid reservoir and the effective reservoir caused by alteration. When the index factor is greater than 31, it is an invalid reservoir, and when it is less than 31, it is an effective reservoir:

[0043]

[0044] Where: CNL, is compensated neutron logging, %; R D , is the deep lateral resistivity logging, Ω·m.

[0045] Step 3: using the logging response characteristics of the divided invalid reservoirs due to alteration and the valid reservoirs without alteration, respectively calculate the total reserves of the reservoir and the reserves of the invalid reservoir. In the reserve calculation method step, according to the identified invalid reservoirs and valid reservoirs, the total reserves of the reservoir and the reserves of the invalid reservoir are calculated using the reserve calculation method;

[0046] Step 4: Calculate the reserves of the target wells in the target area according to the reserve calculation method, then calculate the reserves of the invalid reservoirs, and finally deduct the reserves of the altered invalid reservoirs to obtain the final result reserves.

[0047] The present invention improves the calculation process of volcanic rock reserves by deducting the reserves of invalid reservoirs caused by dissolution and alteration, thereby improving the calculation accuracy of reservoir reserves and being more in line with actual conditions.

[0048] In the specific embodiment 1 of the application of the present invention, the calculation of the reserves of the volcanic reservoir of the X4 well in a certain oil field is taken as an example to illustrate the specific implementation method of the patent of the present invention.

[0049] The first step is to analyze the influence of dissolution and alteration on the reservoir using different core slices ( Figure 2) and other relevant information, analyze the characteristics of dissolution and alteration. The core on the left has feldspar dissolution, and flaky chlorite is distributed in the pores. The core on the right has feldspar dissolution, and carbon and pyrite are distributed in the pores. It can be found that when severe dissolution and alteration occur, it will show silky characteristics, the pore structure of the reservoir will deteriorate, and the permeability will deteriorate. Alteration has an important control effect on the formation of volcanic rock reservoirs, which is mainly manifested in: devitrification and dissolution will produce secondary pores such as intercrystalline pores and dissolution pores, which are easy to form favorable reservoirs; conversely, the secondary minerals produced by alteration will fill the reservoir pores and cracks, reducing the effectiveness of the reservoir pores. What is said here is that the secondary minerals produced by alteration fill the reservoir space and form an invalid reservoir;

[0050] The second step is to further determine the response characteristics of the invalid reservoir and the effective reservoir caused by the alteration on conventional logging based on the identification of the alteration characteristics. The soil produced by the alteration often contains a large amount of crystalline water, which fills the pores and cracks of the rock, such as the 1070m-1105m layer of the X4 well in the example, which causes the neutron logging value to increase, the density logging value to decrease, and the resistivity to decrease, showing good reservoir characteristics, but the actual seepage characteristics are poor, which is a non-reservoir or a poor reservoir. Generally, intermediate-basic volcanic rocks are more susceptible to alteration, and primary pores are easily filled. Therefore, alteration is a common phenomenon in volcanic rocks, and abnormal responses appear in the logging curve and affect the effective reservoir space ( Figure 3 ). Alteration also has a great influence on the measurement results of nuclear magnetic resonance logging. There are fewer macropores in nuclear magnetic resonance, and small and micropores are the main ones. When volcanic rocks are altered, their products contain a large amount of bound water, which increases the porosity of clay bound water. At the same time, clay minerals fill the reservoir space, which reduces the effective porosity of nuclear magnetic resonance. The compensated neutrons and deep lateral resistivity of the alteration characteristic sensitive logging curve are selected. Through research and analysis, the compensated neutrons greater than 31% and the deep lateral resistivity less than 10Ω·m are used as the boundaries of the clay-altered sensitive curve. The parameters are used to establish the identification indicator factors of invalid reservoirs and effective reservoirs caused by alteration. When the index factor is greater than 31, it is an invalid reservoir, and less than 31 is an effective reservoir:

[0051]

[0052] Where: CNL, is compensated neutron logging, %; R D , is the deep lateral resistivity logging, Ω·m.

[0053] The third step is to study the reserve calculation method. The present invention eliminates the problem of invalid reservoir reserve calculation caused by alteration and improves the reserve parameters to achieve the accuracy of reserve calculation. The well profile analysis of some wells in the target area, combined with the previous research on the structural characteristics of Carboniferous volcanic rock weathering bodies, shows that there is a strong alteration zone (hydrolysis zone) at the top of the Carboniferous, with large neutrons and low resistivity, but poor permeability, which plays a shielding role and controls the oil-bearing top boundary. The solid line is the top of the oil and gas display ( Figure 4 ), it can be seen that the dissolution development in this area is obvious in the lateral direction; the total reserves of the reservoir and the reserves of the invalid reservoir are calculated respectively by using the logging response characteristics of the divided effective reservoir and invalid reservoir. In the reserve calculation method step, according to the identified invalid reservoir and effective reservoir, the total reserves of the reservoir and the invalid reservoir reserves are calculated by using the reserve calculation method, which are 58.64 and 10.97 respectively, and the invalid reservoir reserves account for 18.71%. The final reserves after deducting the invalid reservoir reserves are 47.67;

[0054] The fourth step is to calculate the reserves of the target wells in the target area according to the reserve calculation method, and then calculate the reserves of the invalid reservoirs caused by alteration. Finally, the reserves of the invalid reservoirs are deducted to obtain the final result reserves (Table 1). The results show that alteration has a great influence on the reserves of volcanic rock reservoirs. Therefore, it is of great significance to consider the deduction of the invalid reservoir reserves caused by alteration in volcanic rocks in the calculation of volcanic rock reserves and the subsequent exploration and development.

[0055] Table 1 Final result reserve table

[0056]

[0057]

[0058] In the specific embodiment 2 of the application of the present invention, the calculation of the reserves of the volcanic reservoir of the X3 well in a certain oil field is taken as an example to illustrate the specific implementation method of the patent of the present invention.

[0059] The first step is to analyze the characteristics of dissolution and alteration based on the effects of dissolution and alteration on reservoirs, using different core thin section analyses and other relevant data. Alteration has an important controlling effect on the formation of volcanic rock reservoirs, which is mainly manifested in the following ways: devitrification and dissolution will produce secondary pores such as intercrystalline pores and dissolution pores, which are easy to form favorable reservoirs; conversely, secondary minerals produced by alteration will fill reservoir pores and cracks, reducing the effectiveness of reservoir pores. What is mentioned here is that secondary minerals produced by alteration fill the reservoir space and form invalid reservoirs;

[0060] The second step is to further determine the response characteristics of invalid reservoirs and effective reservoirs caused by alteration on conventional logging based on the identification of the alteration characteristics. The soil produced by alteration often contains a large amount of crystalline water, which fills the pores and cracks of the rock, such as the 1475m-1500m layer of the X3 well in the example, which causes the neutron logging value to increase, the density logging value to decrease, and the resistivity to decrease, showing good reservoir characteristics, but the actual seepage characteristics are poor, and it is a non-reservoir or a poor reservoir. Generally, intermediate-basic volcanic rocks are more susceptible to alteration, and primary pores are easily filled. Therefore, alteration is a common phenomenon in volcanic rocks, and abnormal responses appear in the logging curve and affect the effective storage space ( Figure 5 ). Alteration also has a great influence on the measurement results of nuclear magnetic resonance logging. There are fewer macropores in nuclear magnetic resonance, and small and micropores are the main ones. When volcanic rocks are altered, their products contain a large amount of bound water, which increases the porosity of clay bound water. At the same time, clay minerals fill the reservoir space, which reduces the effective porosity of nuclear magnetic resonance. The compensated neutrons and deep lateral resistivity of the alteration characteristic sensitive logging curve are selected. Through research and analysis, the compensated neutrons greater than 31% and the deep lateral resistivity less than 10Ω·m are used as the boundaries of the clay-altered sensitive curve. The parameters are used to establish the identification indicator factors of invalid reservoirs and effective reservoirs caused by alteration. When the index factor is greater than 31, it is an invalid reservoir, and less than 31 is an effective reservoir:

[0061]

[0062] Where: CNL, is compensated neutron logging, %; R D , is the deep lateral resistivity logging, Ω·m.

[0063] The third step is to conduct research on the reserve calculation method. The present invention deducts the problem of invalid reservoir reserve calculation caused by alteration and improves the reserve parameters to achieve the accuracy of reserve calculation. The total reserves of the reservoir and the reserves of the invalid reservoir are calculated respectively by using the logging response characteristics of the divided effective reservoir and invalid reservoir. In the steps of the reserve calculation method, according to the identified invalid reservoir and effective reservoir, the total reserves of the reservoir and the invalid reservoir reserves are calculated by using the reserve calculation method, which are 221.64 and 6.31 respectively. The invalid reservoir reserves account for 2.85%, and the final reserves after deducting the invalid reservoir reserves are 215.33;

[0064] In the specific embodiment 3 of the application of the present invention, the calculation of the reserves of the volcanic reservoir of the X6 well in a certain oil field is taken as an example to illustrate the specific implementation method of the patent of the present invention.

[0065] The first step is to analyze the influence of dissolution and alteration on the reservoir using different core slices ( Figure 2) and other relevant data to analyze the characteristics of dissolution and alteration. Alteration has an important controlling effect on the formation of volcanic rock reservoirs, which is mainly manifested in the following aspects: devitrification and dissolution will produce secondary pores such as intercrystalline pores and dissolution pores, which are easy to form favorable reservoirs; on the contrary, the secondary minerals produced by alteration will fill the reservoir pores and cracks, reducing the effectiveness of the reservoir pores. What is mentioned here is that the secondary minerals produced by alteration fill the reservoir space and form an invalid reservoir;

[0066] The second step is to further determine the response characteristics of invalid reservoirs and effective reservoirs caused by alteration on conventional logging based on the identification of the alteration characteristics. The soil produced by alteration often contains a large amount of crystalline water, which fills the pores and cracks of the rock, such as the 1030m-1130m layer of the X6 well in the example, which causes the neutron logging value to increase, the density logging value to decrease, and the resistivity to decrease, showing good reservoir characteristics, but the actual seepage characteristics are poor, and it is a non-reservoir or a poor reservoir. Generally, intermediate-basic volcanic rocks are more susceptible to alteration, and primary pores are easily filled. Therefore, alteration is a common phenomenon in volcanic rocks, and abnormal responses appear in the logging curve and affect the effective reservoir space ( Figure 6 ). Alteration also has a great influence on the measurement results of nuclear magnetic resonance logging. There are fewer macropores in nuclear magnetic resonance, and small and micropores are the main ones. When volcanic rocks are altered, their products contain a large amount of bound water, which leads to an increase in the clay bound water porosity. At the same time, clay minerals fill the reservoir space, which reduces the effective porosity of nuclear magnetic resonance. In the 1080m-1090m layer of the well, similar three-porosity display characteristics of good physical properties and low resistivity appeared, but the wellbore curve showed a large expansion phenomenon and the signal spectrum at the nuclear magnetic resonance logging had an obvious backward shift phenomenon. It is believed that this layer section is not caused by alteration. The compensated neutron and deep lateral resistivity of the alteration characteristic sensitive logging curve were selected. Through research and analysis, the compensated neutron greater than 31% and the deep lateral resistivity less than 10Ω·m were used as the boundaries of the clay-altered alteration characteristic sensitive curve. The parameters were used to establish the identification indicator factors of invalid reservoirs and effective reservoirs caused by alteration. When the index factor is greater than 31, it is an invalid reservoir, and when it is less than 31, it is an effective reservoir:

[0067]

[0068] Where: CNL, is compensated neutron logging, %; R D , is the deep lateral resistivity logging, Ω·m.

[0069] The third step is to conduct research on the reserve calculation method. The present invention deducts the problem of invalid reservoir reserve calculation caused by alteration and improves the reserve parameters to achieve the accuracy of reserve calculation. The total reserves of the reservoir and the reserves of the invalid reservoir are calculated respectively by using the logging response characteristics of the divided effective reservoir and invalid reservoir. In the steps of the reserve calculation method, according to the identified invalid reservoir and effective reservoir, the total reserves of the reservoir and the invalid reservoir reserves are calculated by using the reserve calculation method, which are 89.17 and 11.23 respectively. The invalid reservoir reserves account for 12.59%, and the final reserves after deducting the invalid reservoir reserves are 77.94;

[0070] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0071] Except for the technical features described in the specification, all other technical features are known technologies to those skilled in the art.

Claims

1. A correction method based on the influence of dissolved alteration reservoir on volcanic rock reserve calculation, characterized in that: The correction method based on the influence of dissolved altered reservoir on volcanic rock reserve calculation includes: Step 1: Use core thin section analysis to determine the alteration mechanism and analyze the characteristics of dissolution alteration; Step 2, using core calibration logging to determine the logging response characteristics of the invalid reservoir due to alteration; Step 3, determining the total reservoir reserves and the ineffective reservoir reserves by using the reserve calculation method; Step 4, determining the final volcanic rock reserves as the reserves after deducting the invalid reservoir reserves; In step 1, according to the results of the influence of dissolution and alteration on the reservoir, the characteristics of dissolution and alteration are analyzed by core thin section analysis and other relevant data. Alteration plays an important role in controlling the formation of volcanic rock reservoirs. The control effect of alteration on the formation of volcanic rock reservoirs is manifested as follows: devitrification and dissolution will produce secondary pores such as intercrystalline pores and dissolution pores, which are easy to form favorable reservoirs; conversely, the secondary minerals produced by alteration will fill the reservoir pores and cracks, reduce the effectiveness of the reservoir pores, and fill the reservoir space for the secondary minerals produced by alteration, forming an invalid reservoir; In step 2, according to the identification of the alteration characteristics, the response characteristics of the invalid reservoir and the effective reservoir of clay-altered alteration on conventional logging are further determined. The clay produced by the alteration often contains a large amount of crystal water, which fills the pores and cracks of the rock, resulting in an increase in the neutron logging value, a decrease in the density logging value, and a decrease in the resistivity, showing good reservoir characteristics, but the actual seepage characteristics are poor, and it is a non-reservoir or a poor reservoir. Intermediate-basic volcanic rocks are more susceptible to alteration, and primary pores are easily filled; the alteration characteristic sensitive logging curve is selected to compensate for the neutron and deep lateral resistivity; The compensation neutron greater than 31% and the deep lateral resistivity less than 10Ω·m are used as the limits of the sensitive parameters of the logging curve of clay alteration characteristics. The sensitive parameters are used to establish the identification indicator factors of invalid reservoirs and effective reservoirs caused by alteration. When the index factor is greater than 31, it is an invalid reservoir, and when it is less than 31, it is an effective reservoir: Where: CNL is compensated neutron logging, %; R D is the deep lateral resistivity log, Ω·m; In step 3, the total reserves of the reservoir and the reserves of the invalid reservoir are calculated respectively by using the logging response characteristics of the invalid reservoir due to alteration and the valid reservoir without alteration; According to the identified invalid reservoirs and effective reservoirs, the total reservoir reserves and invalid reservoir reserves are calculated using the reserve calculation method; In step 4, the reserves of the target wells in the target area are calculated according to the reserves calculation method, and then the reserves of the invalid reservoirs are calculated. Finally, the reserves of the altered invalid reservoirs are deducted to obtain the final result reserves.

2. The method for correcting the influence of dissolved altered reservoirs on volcanic rock reserve calculation according to claim 1 is characterized in that: In step 3, the calculation formulas for the total volume of crude oil geological reserves and the volume of crude oil altered reservoir geological reserves are: Where: N 总 - Total geological reserves of crude oil by volume, 10 4 m 3 ; N 蚀变 -Oil volume alteration reservoir geological reserves, 10 4 m 3 ; B oi -Crude oil volume coefficient; A-Oil-bearing area, km 3 ; H 总 -Total effective thickness of reservoir, m; H 蚀变 -Effective thickness of altered reservoir, m; Φ e- Effective porosity, decimal; So-oil saturation, decimal.

3. The method for correcting the influence of dissolved altered reservoirs on volcanic rock reserve calculation according to claim 1, characterized in that: In step 4, determine the final volcanic rock reserves N 最终 The formula is: N 最终 =N 总 -N 蚀变 Where: N 总 - Total geological reserves of crude oil by volume, 10 4 m 3 ; N 蚀变 -Oil volume alteration reservoir geological reserves, 10 4 m 3 .

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