Tight oil reservoir lithogenous phase quantitative characterization method and device based on pore transformation strength

Abstract

The invention relates to the technical field of oil and gas field development, and relates to a compact oil reservoir lithogenous phase quantitative characterization method and device based on pore transformation strength, and the method comprises the steps: obtaining the pore loss amount caused by the cementation effect, the pore loss amount caused by mechanical compaction, and the pore increase amount caused by the corrosion effect in a research area; based on the surface porosity of the research area, the pore loss amount caused by the cementation effect, the pore loss amount caused by mechanical compaction and the pore increment amount caused by the corrosion effect, the modification strength of the cementation effect on pores, the modification strength of the compaction effect on the pores and the modification strength of the corrosion effect on the pores are obtained; according to the modification strength of the cementing effect on the pores, the modification strength of the compaction effect on the pores and the modification strength of the corrosion effect on the pores, a tight oil reservoir diagenetic phase division parameter table is constructed; and determining the diagenetic phase of the target tight oil reservoir based on the diagenetic phase division parameter table of the tight oil reservoir. The method can provide a certain guiding effect for tight oil-gas exploration, and can be used for reference of similar cases.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas field development, and particularly relates to a method and device for quantitatively characterizing tight oil reservoir diagenetic facies based on pore reconstruction intensity. BACKGROUND

[0002] China is rich in tight oil resources, and research on reservoir classification and characterization has been very extensive and in-depth in the process of evaluating tight oil reservoir geology. From the 1960s and 1970s to the 21st century, the theory of oil and gas reservoir formation evolved from "source control theory" which took source rock as the main research object, "belt control theory" which took structural belt and oil and gas accumulation belt as the main research object, to "facies control theory" which took structure, sedimentary facies and diagenetic facies as the research object (Zou Canliang et al., 2005, 2008). Under the guidance of facies control theory, research on structure and sedimentary facies has been relatively mature, but as a key factor controlling reservoir development, basic research and quantitative evaluation of diagenetic facies are relatively shallow.

[0003] Reservoirs are constantly undergoing sedimentation and diagenesis, and the present reservoirs exhibit physical properties, pore structure, wettability, oil content, and rock mechanics heterogeneity, which are closely related to diagenetic evolution. The concept of diagenetic facies was first proposed by foreign scholar Railsback in 1984, and later Chen Yanhua defined diagenetic facies as the sum of petrologic, geochemical and petrophysical characteristics reflecting the diagenetic environment. Zou Canliang (2008) pointed out that diagenetic facies is the result of the comprehensive action of structure, fluid, temperature and pressure on sediments, and is mainly a genetic marker for characterizing the properties, types and advantages and disadvantages of reservoirs. It can be used to study the formation mechanism, spatial distribution and quantitative evaluation of reservoirs.

[0004] Current research on diagenetic facies mainly focuses on the division of diagenetic types and stages and the qualitative evaluation of pore reconstruction. Zou Canliang (2008) divided diagenetic facies into two categories: expansion diagenetic facies and densification diagenetic facies, and used the naming method of "porosity and permeability grade + rock type + diagenetic type", such as "low porosity and permeability sandstone dissolution facies". This method to some extent reflects the main controlling factors of pore evolution and is relatively intuitive and effective. However, for the current exploration and development requirements, only qualitative research on diagenesis cannot achieve effective development of oil and gas.

[0005] In terms of quantitatively characterizing the degree of pore reconstruction, previous methods have successively undergone quantitative characterization methods based on apparent dissolution rate, quantitative characterization methods based on apparent compaction rate, apparent cementation rate, micro-porosity and surface porosity calculation "diagenetic comprehensive coefficient", however, the limitations of these methods are that they only divide diagenetic facies, and are not associated with pore evolution, and the results are similar to qualitative division methods (Zou Cailiang et al., 2009; Yang Ning et al., 2014; Liu Hongkun et al., 2023). Methods for quantitatively characterizing pore reconstruction intensity based on diagenesis still need to be improved and innovated. SUMMARY

[0006] The present application aims to provide a method and device for quantitatively characterizing diagenetic facies of tight oil reservoirs based on pore reconstruction intensity. To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] A method for quantitatively characterizing diagenetic facies of tight oil reservoirs based on pore reconstruction intensity, characterized in that the method comprises,

[0008] obtaining the pore loss amount caused by cementation, the pore loss amount caused by mechanical compaction, and the pore increase amount caused by dissolution in the study area;

[0009] based on the surface porosity of the study area, the pore loss amount caused by cementation, the pore loss amount caused by mechanical compaction, and the pore increase amount caused by dissolution, obtaining the reconstruction intensity of pores by cementation, the reconstruction intensity of pores by compaction, and the reconstruction intensity of pores by dissolution;

[0010] constructing a diagenetic facies division parameter table for tight oil reservoirs according to the reconstruction intensity of pores by cementation, the reconstruction intensity of pores by compaction, and the reconstruction intensity of pores by dissolution;

[0011] determining the diagenetic facies of the target tight oil reservoir based on the diagenetic facies division parameter table for tight oil reservoirs.

[0012] Further, the reconstruction intensity of pores by cementation is as follows:

[0013]

[0014] wherein E 胶结 is the reconstruction intensity of pores by cementation, is the pore loss amount caused by cementation, is the surface porosity of the study area, is the pore loss amount caused by mechanical compaction, is the pore increase amount caused by dissolution.

[0015] Further,

[0016] wherein E压实 the reformation intensity of the porosity by mechanical compaction, the loss of porosity caused by cementation, the surface porosity of the study area, the loss of porosity caused by mechanical compaction, the increase of porosity caused by dissolution.

[0017] Further,

[0018] In the formula, E 溶蚀 the reformation intensity of the porosity by mechanical compaction, the loss of porosity caused by cementation, the surface porosity of the study area, the loss of porosity caused by mechanical compaction, the increase of porosity caused by dissolution.

[0019] Further,

[0020]

[0021]

[0022]

[0023] In the formula, Q the measured porosity of the sample, 胶结物 the content of cement in the rock framework, the porosity at a certain depth after only mechanical compaction, the surface porosity of the study area.

[0024] Further,

[0025] In the formula, C is the compression coefficient of the rock; and z is the burial depth of the sample.

[0026] Further, the parameter table for dividing the diagenetic facies of the tight oil reservoir divides the diagenetic facies of the tight oil reservoir into a compaction facies, a cementation facies, a dissolution-cementation facies, a cementation-dissolution facies, or a dissolution facies, wherein,

[0027] when the reformation intensity of the porosity by compaction is ≥ 85%, the diagenetic facies of the tight oil reservoir is the compaction facies;

[0028] when the reformation intensity of the porosity by compaction is < 85%, the diagenetic facies of the tight oil reservoir is the cementation facies, the dissolution-cementation facies, the cementation-dissolution facies, or the dissolution facies.

[0029] Further, when the intensity of the compaction on the pore is less than 85%, and the intensity of the dissolution on the pore / the intensity of the cementation on the pore is less than or equal to 0.5, the diagenetic facies of the tight oil reservoir is a cementation facies; or,

[0030] When the intensity of the compaction on the pore is less than 85%, and 0.5 < the intensity of the dissolution on the pore / the intensity of the cementation on the pore ≤ 1.0, the diagenetic facies of the tight oil reservoir is a dissolution-cementation facies; or,

[0031] When the intensity of the compaction on the pore is less than 85%, and 1.0 < the intensity of the dissolution on the pore / the intensity of the cementation on the pore ≤ 1.5, the diagenetic facies of the tight oil reservoir is a cementation-dissolution facies; or,

[0032] When the intensity of the compaction on the pore is less than 85%, and the intensity of the dissolution on the pore / the intensity of the cementation on the pore is greater than 1.5, the diagenetic facies of the tight oil reservoir is a dissolution facies.

[0033] The application further provides a device for quantitatively characterizing diagenetic facies of a tight oil reservoir based on the intensity of pore modification, which comprises,

[0034] A first acquisition unit is configured to acquire the amount of pore loss caused by cementation, the amount of pore loss caused by mechanical compaction, and the amount of pore increase caused by dissolution;

[0035] A second acquisition unit is configured to acquire the intensity of the cementation on the pore, the intensity of the compaction on the pore, and the intensity of the dissolution on the pore based on the surface porosity of the research area, the amount of pore loss caused by cementation, the amount of pore loss caused by mechanical compaction, and the amount of pore increase caused by dissolution;

[0036] A construction unit is configured to construct a diagenetic facies classification parameter table of the tight oil reservoir according to the intensity of the cementation on the pore, the intensity of the compaction on the pore, and the intensity of the dissolution on the pore.

[0037] A determination unit is configured to determine the diagenetic facies of the target tight oil reservoir based on the diagenetic facies classification parameter table of the tight oil reservoir.

[0038] Further,

[0039] The intensity of the cementation on the pore is calculated according to the following formula:

[0040]

[0041] The intensity of the compaction on the pore is calculated according to the following formula:

[0042]

[0043] The reconstruction intensity of the dissolution to the pore is as follows:

[0044]

[0045] In the formula, E 胶结 is the reconstruction intensity of the cementation to the pore, is the pore loss amount caused by the cementation, is the surface porosity of the research area, is the pore loss amount caused by the mechanical compaction, is the pore increase amount caused by the dissolution, E 压实 is the reconstruction intensity of the mechanical compaction to the pore, E 溶蚀 is the reconstruction intensity of the dissolution to the pore.

[0046] Further, the second construction unit is used for dividing the tight oil reservoir diagenetic facies into a compaction facies, a cementation facies, a dissolution-cementation facies, a cementation-dissolution facies or a dissolution facies according to a tight oil reservoir diagenetic facies division parameter table, wherein,

[0047] When the reconstruction intensity of the compaction to the pore is greater than or equal to 85%, the tight oil reservoir diagenetic facies is the compaction facies.

[0048] When the reconstruction intensity of the compaction to the pore is less than 85%, the tight oil reservoir diagenetic facies is the cementation facies, the dissolution-cementation facies, the cementation-dissolution facies or the dissolution facies.

[0049] Technical effects and advantages of the present application:

[0050] The prerequisite for the systematic research on the reservoir porosity evolution in the present application is to clarify the diagenesis of the reservoir. After the diagenesis is clarified, the quantitative description of the diagenetic reconstruction can accurately and intuitively reflect the main control factors of the reservoir quality. Based on the systematic research on the reservoir characteristics and the diagenesis, the reservoir diagenetic evolution sequence is reconstructed, the influence of each diagenesis on the reservoir porosity is quantitatively calculated, and then the quantitative evolution mode of the reservoir porosity is established. Thus, the requirements of the fine characterization of the reservoir are met, and certain guidance is provided for the exploration of the tight oil and gas, which can be used as a reference for similar cases.

[0051] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and achieved by the structures indicated in the specification and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 It is the flow chart of the tight oil reservoir diagenetic facies quantitative characterization method based on the pore reconstruction intensity of the present application;

[0053] Figure 2aFor the cement content in the sample contained in the XRD whole rock analysis data in the embodiment of the present application is statistically scattered according to the depth;

[0054] Figure 2b For the loss of porosity of the sandy conglomerate and the sandy rock in the research area caused by cementation is obtained according to the formula 1 in the embodiment of the present application, and a scatter plot is obtained;

[0055] Figure 3a For the inner envelope line of the evolution trend with the depth of the sandy rock and the sandy conglomerate is fitted to obtain the surface porosity and the compaction coefficient of the sandy conglomerate and the sandy rock in the research area in the embodiment of the present application;

[0056] Figure 3b For the compaction loss porosity of the sandy conglomerate and the sandy rock in the research area is evaluated according to the formula 2 in the embodiment of the present application;

[0057] Figure 3c For the porosity increased by the dissolution of the sandy conglomerate and the sandy rock in the research area is reduced in combination with the formula 5 in the embodiment of the present application;

[0058] Figure 4 For the compaction-cementation-dissolution porosity reconstruction triangle and the lithofacies division in the embodiment of the present application;

[0059] Figure 5a For the porosity distribution characteristics of the reservoir under the lithofacies of the sandy conglomerate in the third member of Fengshen Formation in the embodiment of the present application;

[0060] Figure 5b For the porosity distribution characteristics of the reservoir under the lithofacies of the sandy rock in the second member of Fengshen Formation in the embodiment of the present application;

[0061] Figure 6a For the plane distribution characteristics of the lithofacies of the sandy conglomerate in the third member of Fengshen Formation in the embodiment of the present application;

[0062] Figure 6b For the plane distribution characteristics of the lithofacies of the sandy rock in the second member of Fengshen Formation in the embodiment of the present application. DETAILED DESCRIPTION

[0063] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0064] To solve the problems in the prior art, the present application discloses a method for quantitatively characterizing lithofacies of a tight oil reservoir based on porosity reconstruction intensity, as shown in Figure 1 The method comprises,

[0065] Step 1: obtaining the pore loss amount caused by cementation in the study area, the pore loss amount caused by mechanical compaction, and the pore increase amount caused by dissolution;

[0066] Step 2: obtaining the reconstruction strength of pores caused by cementation, the reconstruction strength of pores caused by compaction, and the reconstruction strength of pores caused by dissolution based on the surface porosity in the study area, the pore loss amount caused by cementation, the pore loss amount caused by mechanical compaction, and the pore increase amount caused by dissolution;

[0067] Step 3: constructing a parameter table for dividing the diagenetic facies of the tight oil reservoir according to the reconstruction strength of pores caused by cementation, the reconstruction strength of pores caused by compaction, and the reconstruction strength of pores caused by dissolution;

[0068] Step 4: determining the diagenetic facies of the target tight oil reservoir based on the parameter table for dividing the diagenetic facies of the tight oil reservoir.

[0069] Compaction pore loss, cementation pore loss and dissolution pore increase are three major mechanisms of pore evolution in the diagenetic process. Based on XRD whole rock analysis, the components in the rock are divided into cement and primary sediment. The compaction curve is determined by the inner envelope of the cement-free porosity with depth, the compaction pore loss is evaluated, and the pores greater than the compaction curve are the dissolution pore increase. The diagenetic reconstruction strength is quantitatively characterized by the compaction pore loss and the dissolution pore increase, and then the diagenetic facies is divided.

[0070] In one specific embodiment of the present application, in step 1, the pore loss amount caused by cementation is the absolute volume of cement in unit volume of rock, therefore, the cementation pore loss amount can be expressed as:

[0071]

[0072] In the formula, is the measured porosity of the sample, with a unit of %; Q 胶结物 is the content of cement in the rock framework, with a unit of %; is the pore loss amount caused by cementation, with a unit of %.

[0073] It is assumed that when no cementation occurs, the evolution of porosity is mainly controlled by mechanical compaction and dissolution, and its size is the sum of the present measured porosity and the cementation loss porosity . In the case of the same lithology, The scatter plot inner envelope about the burial depth is the normal evolution trend of the pores under the mechanical compaction, which is exponentially attenuated with the burial depth. The normal evolution trend line of the pores can be expressed as:

[0074]

[0075] In the formula, is the porosity at a certain depth after mechanical compaction only, with the unit of %; is the surface porosity of the study area, with the unit of %; C is the rock compression coefficient, dimensionless; and z is the sample burial depth, with the unit of m.

[0076] Therefore, the porosity loss amount caused by compaction can be expressed as:

[0077]

[0078] In the formula, is the porosity loss amount caused by mechanical compaction, with the unit of %; and other parameters are the same as above.

[0079] In the formula, In the depth evolution diagram, the part of porosity exceeding the normal compaction curve is the pore increase caused by dissolution, and thus the dissolution pore increase amount can be expressed as:

[0080]

[0081] In the formula, is the porosity increase amount caused by dissolution.

[0082] In one specific embodiment of the present application, for step 2, the modification efficiency of three types of diagenesis on porosity is normalized, and the porosity modification intensity is as follows: the modification intensity of cementation on porosity is as follows:

[0083]

[0084] In the formula, E 胶结 is the modification intensity of cementation on porosity, with the unit of %; is the porosity loss amount caused by cementation, is the surface porosity of the study area, is the porosity loss amount caused by mechanical compaction, is the porosity increase amount caused by dissolution.

[0085]

[0086] In the formula, E 压实 is the modification intensity of mechanical compaction on porosity, with the unit of %; is the porosity loss amount caused by cementation, is the surface porosity of the study area, is the porosity loss amount caused by mechanical compaction, is the porosity increase amount caused by dissolution.

[0087]

[0088] E = (P0-P1) / P0 溶蚀 is the reconstruction strength of the dissolution to the pores, unit: %; is the loss of the pores caused by the cementation, is the surface porosity of the research area, is the loss of the pores caused by the mechanical compaction, is the increase of the pores caused by the dissolution.

[0089] In one specific embodiment of the present application, for step 3, according to the proportion of the three pore reconstruction mechanisms, the dense oil reservoir diagenetic facies is divided into the following types by using the dense oil reservoir diagenetic facies division parameter table: compaction facies, cementation facies, dissolution-cementation facies, cementation-dissolution facies and dissolution facies, wherein, as shown in Table 1:

[0090] When the reconstruction strength of the compaction to the pores is ≥ 85%, the dense oil reservoir diagenetic facies is the compaction facies;

[0091] When the reconstruction strength of the compaction to the pores is < 85%, the dense oil reservoir diagenetic facies is the cementation facies, the dissolution-cementation facies, the cementation-dissolution facies or the dissolution facies, wherein,

[0092] When the reconstruction strength of the compaction to the pores is < 85%, and the reconstruction strength of the dissolution to the pores / the reconstruction strength of the cementation to the pores is ≤ 0.5, the dense oil reservoir diagenetic facies is the cementation facies; or,

[0093] When the reconstruction strength of the compaction to the pores is < 85%, and 0.5 < the reconstruction strength of the dissolution to the pores / the reconstruction strength of the cementation to the pores ≤ 1.0, the dense oil reservoir diagenetic facies is the dissolution-cementation facies; or,

[0094] When the reconstruction strength of the compaction to the pores is < 85%, and 1.0 < the reconstruction strength of the dissolution to the pores / the reconstruction strength of the cementation to the pores ≤ 1.5, the dense oil reservoir diagenetic facies is the cementation-dissolution facies; or,

[0095] When the reconstruction strength of the compaction to the pores is < 85%, and the reconstruction strength of the dissolution to the pores / the reconstruction strength of the cementation to the pores is greater than 1.5, the dense oil reservoir diagenetic facies is the dissolution facies.

[0096] Table 1 diagenetic facies division parameter table

[0097]

[0098] The present application also provides a device for quantitatively characterizing the dense oil reservoir diagenetic facies based on the pore reconstruction strength, which comprises,

[0099] The first obtaining unit is configured to obtain a pore loss amount caused by cementation, a pore loss amount caused by mechanical compaction, and a pore increase amount caused by dissolution;

[0100] The second obtaining unit is configured to obtain a cementation reconstruction intensity on pores, a compaction reconstruction intensity on pores, and a dissolution reconstruction intensity on pores based on the surface porosity of the research area, the pore loss amount caused by cementation, the pore loss amount caused by mechanical compaction, and the pore increase amount caused by dissolution;

[0101] The constructing unit is configured to construct a tight oil reservoir diagenetic facies division parameter table according to the cementation reconstruction intensity on pores, the compaction reconstruction intensity on pores, and the dissolution reconstruction intensity on pores.

[0102] The determining unit is configured to determine a diagenetic facies of a target tight oil reservoir based on the tight oil reservoir diagenetic facies division parameter table.

[0103] In one specific embodiment of the present application, the cementation reconstruction intensity on pores is calculated according to the following formula:

[0104]

[0105] The compaction reconstruction intensity on pores is calculated according to the following formula:

[0106]

[0107] The dissolution reconstruction intensity on pores is calculated according to the following formula:

[0108]

[0109] In the formula, E 胶结 is the cementation reconstruction intensity on pores, is the pore loss amount caused by cementation, is the surface porosity of the research area, is the pore loss amount caused by mechanical compaction, is the pore increase amount caused by dissolution, E 压实 is the compaction reconstruction intensity on pores, E 溶蚀 is the dissolution reconstruction intensity on pores.

[0110] In one specific embodiment of the present application, the second constructing unit is configured to divide the tight oil reservoir diagenetic facies into a compaction facies, a cementation facies, a dissolution-cementation facies, a cementation-dissolution facies, or a dissolution facies according to the tight oil reservoir diagenetic facies division parameter table, wherein,

[0111] When the compaction reconstruction intensity on pores is greater than or equal to 85%, the diagenetic facies of the tight oil reservoir is the compaction facies.

[0112] When the pore transformation intensity of compaction is less than 85%, the diagenetic phase of tight oil reservoir is cementation phase, dissolution-cementation phase, cementation-dissolution phase or dissolution phase.

[0113] Regarding the apparatus in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0114] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0115] Taking the Fengcheng Formation reservoir in the K81 well area on the southern edge of the Mahu Sag as an example, based on the XRD whole-rock analysis data, the cement content in the sample was counted and a scatter plot was made according to the depth ( Figure 2a According to formula 1, the porosity loss of the sandstone in the study area due to cementation is The average porosity loss of sandstone due to cementation is about 10.2%. Figure 2b ).

[0116] The inner envelope of the evolution trend of sandstone and conglomerate with depth was fitted using the data processing software Organic Pro. The surface porosity of conglomerate in the study area was 40%, and the compaction coefficient C was 0.0055; the surface porosity of sandstone was 45%, and the compaction coefficient C was 0.0045 ( Figure 3a According to the evaluation results of formula 2, the porosity loss of the sandstone in the study area due to compaction is between 34.8% and 37.2%, with an average of 35.6%; the porosity loss of the sand body due to compaction is between 37.4% and 41.1%, with an average of 39.5% ( Figure 3b ). Combining Formula 5 to restore the dissolution transformation intensity in the study area, the porosity increased by the dissolution of sandstone and conglomerate ranges from 0..3% to 15.2%, with an average of 5.7%; the porosity formed by the dissolution of sandstone ranges from 1.1% to 34.6, with an average of about 9.0% ( Figure 3c ).

[0117] According to the evaluation results, the Fengcheng Formation conglomerate in the study area mainly develops compaction phase, dissolution-cementation phase, cementation-dissolution phase and dissolution phase, while the sandstone is mainly in dissolution-cementation phase, cementation-dissolution phase and dissolution phase ( Figure 4) Statistics of different diagenetic facies porosity distribution, dissolution facies porosity is the highest, between 5.7% ~ 12.4%, an average of 9%; followed by cementation-dissolution facies, the reservoir porosity between 4.4% ~ 9.4%, an average of 6.6%; again, the compaction facies, porosity between 1.6% ~ 7.5, an average of 4.9%; the lowest porosity of dissolution-cementation facies, porosity between 1.0% ~ 6.8%, an average of 3.1% (Figure 5). Thus, the dissolution facies and cementation-dissolution facies are the development of high-quality reservoirs in the area of advantage diagenetic facies, also confirmed that the deep tight reservoir, dissolution plays a crucial role in the development of high-quality reservoirs.

[0118] Calculate the average diagenetic evaluation parameters of each layer of the study area, make the diagenetic facies plane distribution map of the study area (Figures 6 and 7). Figure 6a And Figure 6b It can be seen that the cementation and dissolution in the western near-source area of the Feng 3 Member sandstone are relatively weak, and the compaction modification accounts for more than 85%, which is a mechanical compaction facies; the dissolution modification effect in the central Mahu025-Mahu 5 zone and the southern Jinlong 56-Mahu 39 zone is obvious, which is a dissolution facies, and the corresponding reservoir porosity is also the highest.

[0119] And the Feng 2 II sandstone dissolution is more common, and the zone is mostly cementation-dissolution facies. The dissolution facies is developed in the central Mahu025-Mahu 5 zone, and its distribution range is comparable to that of the Feng 3 Member. The cementation effect is more significant in the northern outer front zone, which belongs to the dissolution-cementation facies, and the reservoir is also the most dense, with a porosity generally lower than 3%.

[0120] Finally, it should be noted that the above only for the preferred embodiments of the present application, and not for the limitation of the present application, although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application, should be included in the protection scope of the present application.

Claims

1. A method for quantitative characterization of diagenetic facies of tight oil reservoirs based on pore modification intensity, characterized in that, The method comprises, obtaining the pore loss amount caused by cementation, the pore loss amount caused by mechanical compaction and the pore increase amount caused by dissolution in the research area; based on the surface porosity, the pore loss amount caused by cementation, the pore loss amount caused by mechanical compaction and the pore increase amount caused by dissolution in the research area, obtaining the reconstruction strength of cementation on pores, the reconstruction strength of compaction on pores and the reconstruction strength of dissolution on pores; according to the reconstruction strength of cementation on pores, the reconstruction strength of compaction on pores and the reconstruction strength of dissolution on pores, constructing a parameter table for the tight oil reservoir diagenetic facies division; based on the parameter table for the tight oil reservoir diagenetic facies division, determining the diagenetic facies of the target tight oil reservoir.

2. The method for quantitatively characterizing the diagenetic facies of tight oil reservoirs based on the modified intensity of porosity according to claim 1, characterized in that, The reconstruction strength of cementation on pores is as follows: where E 胶结 is the modification intensity of the pores by cementation, is the amount of pore loss caused by cementation, is the surface porosity of the study area, is the amount of pore loss caused by mechanical compaction, is the amount of pore increase caused by dissolution.

3. The method according to claim 1, wherein, wherein E 压实 is the amount of porosity loss due to mechanical compaction, is the amount of porosity loss due to cementation, is the surface porosity of the study area, is the amount of porosity loss due to mechanical compaction, is the amount of porosity gain due to dissolution.

4. The method according to claim 1, wherein, wherein E 溶蚀 is the modification intensity of the pores by dissolution, is the loss of porosity caused by cementation, is the surface porosity of the study area, is the loss of porosity caused by mechanical compaction, is the increase in porosity caused by dissolution.

5. The method according to any one of claims 2-4, wherein, wherein Q is the measured porosity of the sample, 胶结物 Qc is the content of the cement in the rock matrix, Qm is the porosity at a certain depth after mechanical compaction only, Qs is the surface porosity of the study area.

6. The method according to claim 5, wherein, wherein C is the rock compression coefficient, and z is the sample burial depth.

7. The method of claim 1, wherein the method is characterized by, The parameter table for the tight oil reservoir diagenetic facies division divides the tight oil reservoir diagenetic facies into compaction facies, cementation facies, dissolution-cementation facies, cementation-dissolution facies or dissolution facies, wherein, when the reconstruction strength of compaction on pores is greater than or equal to 85%, the tight oil reservoir diagenetic facies is compaction facies; when the reconstruction strength of compaction on pores is less than 85%, the tight oil reservoir diagenetic facies is cementation facies, dissolution-cementation facies, cementation-dissolution facies or dissolution facies.

8. The method according to claim 7, wherein, when the reconstruction strength of compaction on pores is less than 85%, and the reconstruction strength of dissolution on pores / the reconstruction strength of cementation on pores is less than or equal to 0.5, the tight oil reservoir diagenetic facies is cementation facies; or, when the reconstruction strength of compaction on pores is less than 85%, and 0.5 or, when the reconstruction strength of compaction on pores is less than 85%, and 1.0 or, when the reconstruction strength of compaction on pores is less than 85%, and the reconstruction strength of dissolution on pores / the reconstruction strength of cementation on pores is greater than 1.5, the tight oil reservoir diagenetic facies is dissolution facies.

9. A device for quantitatively characterizing diagenetic facies of tight oil reservoirs based on pore modification intensity, characterized in that, The device comprises, a first obtaining unit configured to obtain the pore loss amount caused by cementation, the pore loss amount caused by mechanical compaction and the pore increase amount caused by dissolution in the research area; a second obtaining unit configured to obtain the reconstruction strength of cementation on pores, the reconstruction strength of compaction on pores and the reconstruction strength of dissolution on pores based on the surface porosity, the pore loss amount caused by cementation, the pore loss amount caused by mechanical compaction and the pore increase amount caused by dissolution in the research area; The second acquisition unit is configured to acquire the reconstruction strength of the porosity by cementation, the reconstruction strength of the porosity by compaction, and the reconstruction strength of the porosity by dissolution based on the surface porosity of the study area, the porosity loss amount caused by cementation, the porosity loss amount caused by mechanical compaction, and the porosity increase amount caused by dissolution; The construction unit is configured to construct a parameter table for the diagenetic facies of the tight oil reservoir according to the reconstruction strength of the porosity by cementation, the reconstruction strength of the porosity by compaction, and the reconstruction strength of the porosity by dissolution; The determination unit is configured to determine the diagenetic facies of the target tight oil reservoir based on the parameter table for the diagenetic facies of the tight oil reservoir.

10. The device for quantitatively characterizing the diagenetic facies of a tight oil reservoir based on the reconstruction strength of a pore according to claim 9, wherein The reconstruction strength of the porosity by cementation is calculated according to the following formula: The reconstruction strength of the porosity by compaction is calculated according to the following formula: The reconstruction strength of the porosity by dissolution is calculated according to the following formula: where E 胶结 is the modification strength of cementation on porosity, is the porosity loss caused by cementation, is the surface porosity of the study area, is the porosity loss caused by mechanical compaction, is the porosity increase caused by dissolution, E 压实 is the modification strength of mechanical compaction on porosity, E 溶蚀 is the modification strength of dissolution on porosity.

11. The device for quantitatively characterizing the diagenetic facies of tight oil reservoirs based on pore modification strength according to claim 9, characterized in that, The second construction unit is configured to divide the diagenetic facies of the tight oil reservoir into a compaction facies, a cementation facies, a dissolution-cementation facies, a cementation-dissolution facies, or a dissolution facies according to the parameter table for the diagenetic facies of the tight oil reservoir, wherein When the reconstruction strength of the porosity by compaction is greater than or equal to 85%, the diagenetic facies of the tight oil reservoir is the compaction facies. When the reconstruction strength of the porosity by compaction is less than 85%, the diagenetic facies of the tight oil reservoir is the cementation facies, the dissolution-cementation facies, the cementation-dissolution facies, or the dissolution facies.

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