Rock duct connectivity evaluation method and device, server and medium

Abstract

The invention provides a rock duct connectivity evaluation method and device, a server and a medium. The method comprises the following steps: acquiring mercury entering a pore channel with a pore structure in a rock to be evaluated, mercury injection pressures at at least two pressure change points and mercury injection volumes corresponding to the mercury injection pressures; and according to the first energy conservation formula, the second energy conservation formula, the mercury injection pressure and the mercury injection volume, determining the connectivity coefficient of the pore channel, the connectivity coefficient being used for evaluating the connectivity degree of the pore channel in the pore structure shape. The mercury injection pressure and the mercury inlet volume are processed by combining two energy conservation formulas, so that the connectivity coefficient obtained according to the processed mercury injection pressure and mercury inlet volume is more accurate, and the evaluation of the connectivity degree of the pore channel of the rock to be evaluated is more accurate.

Description

Technical Field

[0001] This application relates to the field of geological exploration and development, and in particular to a method, apparatus, server and medium for evaluating the connectivity of rock pores. Background Technology

[0002] Rocks have multiple interconnected channels, which form a porous structure.

[0003] Currently, traditional methods for evaluating the connectivity of pore structures in rocks include the semi-permeable septum method, mercury intrusion porosimetry, and centrifugation. However, these traditional methods often yield significantly different results from actual pore structure connectivity, leading to low accuracy. Summary of the Invention

[0004] This application provides a method, apparatus, server, and medium for evaluating the connectivity of rock channels, so as to improve the accuracy of evaluating the connectivity of channels in a porous structure in rocks.

[0005] In a first aspect, embodiments of this application provide a method for evaluating the connectivity of rock pores. The method includes: obtaining mercury entering a porous structure pore in the rock to be evaluated, the mercury intrusion pressure at at least two pressure change points, and the mercury intrusion volume corresponding to the mercury intrusion pressure; determining the connectivity coefficient of the pore according to a first energy conservation formula, a second energy conservation formula, the mercury intrusion pressure, and the mercury intrusion volume, wherein the connectivity coefficient is used to evaluate the connectivity of the porous structure pore; wherein the first energy conservation formula indicates that the work required for mercury to enter the pore is equal to the sum of the pressure work of the mercury intrusion pressure applied to the mercury and the volume work of the mercury intrusion volume, and the second energy conservation formula indicates that the work required for mercury to enter the pore is equal to the sum of the surface energy generated by the mercury and the pore and the interfacial energy generated by the mercury and the air.

[0006] In some embodiments of the first aspect, the connectivity coefficient of the channel is determined according to the first energy conservation formula, the second energy conservation formula, the mercury injection pressure, and the mercury injection volume, including: constructing a slope model of the channel in the form of a pore structure based on the first energy conservation formula and the second energy conservation formula; inputting the mercury injection pressure and the mercury injection volume into the slope model and outputting a set of discrete slope points; and calculating the connectivity coefficient of the channel based on the set of discrete slope points.

[0007] In some embodiments of the first aspect, constructing a slope model for a porous channel based on a first energy conservation formula and a second energy conservation formula includes: constructing a hyperbolic model for the porous channel based on the first energy conservation formula and the second energy conservation formula. The hyperbolic model includes a mercury intrusion pressure curve and a correlation curve. The mercury intrusion pressure curve represents the relationship between the mercury intrusion pressure and the mercury intrusion volume, and the correlation curve represents the relationship between the mercury intrusion pressure obtained from the conversion of surface energy and interface energy and the mercury intrusion volume. The slope model is calculated based on the logarithm of the hyperbolic model.

[0008] In some embodiments of the first aspect, a hyperbolic model of a porous channel is constructed based on a first energy conservation formula and a second energy conservation formula, including: converting the equivalent relationship between surface energy and interface energy in the second energy conservation formula according to the capillary bundle equivalence assumption principle, obtaining the relationship between mercury injection pressure and mercury injection volume, and obtaining a third energy conservation formula; and constructing a hyperbolic model of a porous channel based on the third energy conservation formula and the first energy conservation formula.

[0009] In some embodiments of the first aspect, the slope model includes a first tangent slope model of the mercury intrusion curve and a second tangent slope model of the associated curve; inputting the mercury intrusion pressure and the mercury injection volume into the slope model and outputting a set of discrete slope points includes: inputting the mercury intrusion pressure and the mercury injection volume into the first tangent slope model to obtain a first set of discrete points; inputting the mercury intrusion pressure and the mercury injection volume into the second tangent slope model to obtain a second set of discrete points; calculating the connectivity coefficient of the channel based on the set of discrete slope points includes: obtaining the connectivity coefficient of the channel based on the first set of discrete points and the second set of discrete points.

[0010] In some embodiments of the first aspect, obtaining the connectivity coefficient of the channel based on a first set of discrete points and a second set of discrete points includes: determining the absolute value of the covariance between the first set of discrete points and the second set of discrete points as the connectivity coefficient of the channel.

[0011] In some embodiments of the first aspect, the connectivity coefficient of the channel is within a preset range, which is calculated based on a preset J-function curve.

[0012] Secondly, a connectivity evaluation device for rock channels is provided, the connectivity evaluation device comprising,

[0013] The acquisition module is used to acquire mercury entering the porous structure of the rock to be evaluated, the mercury intrusion pressure at at least two pressure change points, and the mercury intrusion volume corresponding to the mercury intrusion pressure.

[0014] The calculation module is used to determine the connectivity coefficient of the channels based on the first energy conservation formula, the second energy conservation formula, the mercury injection pressure, and the mercury injection volume. The connectivity coefficient is used to evaluate the degree of connectivity of the channels with a porous structure.

[0015] The third aspect provides a server, including:

[0016] Processor, memory, communication interface;

[0017] Memory is used to store the processor's executable instructions;

[0018] The processor is configured to execute the method of the first aspect by executing executable instructions.

[0019] The fourth aspect provides a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method of the first aspect.

[0020] This application provides a method, apparatus, server, and medium for evaluating the connectivity of rock pores. When mercury enters the porous pores of the rock to be evaluated, the method acquires the mercury intrusion pressure at at least two pressure change points, and the corresponding mercury intrusion volume. Based on the mercury intrusion pressure, the mercury intrusion volume, a first energy conservation formula, and a second energy conservation formula, the connectivity coefficient of the rock pores is obtained to evaluate the degree of connectivity of the rock pores. By combining the two energy conservation formulas to process the mercury intrusion pressure and the mercury intrusion volume, the connectivity coefficient obtained from the processed mercury intrusion pressure and the mercury intrusion volume becomes more accurate, leading to a more accurate evaluation of the connectivity of the rock pores. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of an application scenario for the rock channel connectivity evaluation method provided in the embodiments of this application;

[0023] Figure 2 A schematic flowchart of a method for evaluating the connectivity of rock channels provided in an embodiment of this application;

[0024] Figure 3 A schematic diagram illustrating another application scenario of the rock channel connectivity evaluation method provided in the embodiments of this application;

[0025] Figure 4 Another schematic flowchart of a method for evaluating the connectivity of rock channels provided in an embodiment of this application;

[0026] Figure 5 A schematic diagram illustrating another application scenario of the rock channel connectivity evaluation method provided in the embodiments of this application;

[0027] Figure 6 This is a schematic diagram of mercury intrusion porosimetry curves for rock pores obtained based on traditional evaluation methods.

[0028] Figure 7 A schematic diagram of the vehicle control device provided in the embodiments of this application;

[0029] Figure 8A structural schematic diagram of the vehicle provided in this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments made by those skilled in the art under the guidance of these embodiments are within the scope of protection of this application.

[0031] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0032] Rocks have multiple interconnected channels, which form a porous structure.

[0033] Currently, traditional evaluation methods such as the semi-permeable diaphragm method, mercury intrusion porosimetry, and centrifugation method are used to evaluate the connectivity of porous structures in rocks.

[0034] In traditional evaluation methods, the pore is equivalent to a capillary tube, and the capillary pressure curve of the capillary tube (the pressure added to the surface of the fluid rising or falling in the pore is equivalent to the capillary pressure) is calculated. The connectivity of the pore is evaluated based on the capillary pressure curve.

[0035] When the fluid includes water and oil, there is two-phase flow of oil and water in the pores. In high-permeability reservoirs, traditional evaluation methods only consider the capillary pressure when the water-oil interface in the pores reaches equilibrium, ignoring the dynamic effect of the capillary pressure when the water-oil interface is not in equilibrium. This makes the calculated capillary pressure curves of high-permeability reservoirs inaccurate, and the evaluation of pore connectivity inaccurate.

[0036] In low-permeability reservoirs, the narrow pore throats lead to low permeability and reduced water-oil flow velocities. Compared to high-permeability reservoirs, the dynamic effect of capillary pressure is more pronounced in low-permeability reservoirs when the water-oil interface is not in equilibrium. Capillary pressure curves and assessments of pore connectivity obtained using traditional evaluation methods are therefore less accurate.

[0037] Furthermore, traditional evaluation methods, derived from clastic rocks such as conglomerate and sandstone, have a relatively limited scope of analysis and narrow applicability. For example, when evaluating Middle Eastern channel-type carbonate rocks, due to their unique sedimentary environment, diagenesis, and pore throat composition, traditional methods often result in capillary pressure curves with short plateau periods, complex curve shapes, and indistinct characteristic segments. The calculated pore throat distribution of these rocks is highly dispersed, permeability contributions are scattered, and connectivity assessments are inaccurate, leading to significant discrepancies with the actual conditions of Middle Eastern channel-type carbonate rocks.

[0038] In view of this, this application provides a method, apparatus, server and medium for evaluating the connectivity of rock pores, so as to improve the accuracy of evaluating the connectivity of pore-structured pores in rocks.

[0039] Please see Figure 1 , Figure 1 This is an application scenario of the rock pore connectivity evaluation method according to an embodiment of this application. This application scenario includes a control device 10, a mercury intrusion porosimetry device 20, and the rock to be evaluated by the control device 10. The rock to be evaluated has pores in a porous structure. The connectivity evaluation method is applied to the control device 10. Specifically, the control device 10 controls the mercury intrusion porosimetry device 20 to inject mercury into the pores. The control device 10 acquires the mercury intrusion pressure from the mercury intrusion porosimetry device 20 and the corresponding mercury injection volume. Then, it determines the connectivity of the pores based on the mercury intrusion pressure, the mercury injection volume, a first energy conservation formula, and a second energy conservation formula.

[0040] In some embodiments, the control device may be integrated into the mercury porosimeter.

[0041] In some embodiments, the control device includes a server, mobile phone, tablet computer, desktop computer, laptop computer, handheld computer, notebook computer, and ultra-mobile personal computer (UMPC), etc. In some embodiments, the mercury porosimetry device includes a mercury porosimeter.

[0042] It should be noted that, Figure 1 This is merely a schematic diagram illustrating one application scenario provided by an embodiment of this application. This embodiment does not necessarily represent... Figure 1The document does not limit the actual form of the various devices included, nor does it specify the form of the devices. Figure 1 The interaction methods between devices are limited, and can be set according to actual needs in the specific application of the solution.

[0043] The technical solution of this application will now be described in detail through specific embodiments. It should be noted that the following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0044] Figure 2 This is a flowchart illustrating an embodiment of a method for evaluating the connectivity of rock channels provided in this application. The executing entity in this embodiment can be a control device. The method in this embodiment can be implemented through software, hardware, or a combination of both. Figure 2 As shown, the connectivity evaluation method specifically includes the following steps:

[0045] Step S210: Obtain the mercury entering the porous structure of the rock to be evaluated, the mercury intrusion pressure at at least two pressure change points, and the mercury intrusion volume corresponding to the mercury intrusion pressure.

[0046] like Figure 3 As shown, the rock to be evaluated can be a reservoir rock. The space for fluid flow within the reservoir rock consists of a complex network of tortuous, unequal-sized, and interconnected small channels. These tortuous, unequal-sized, and interconnected small channels form the pore structure.

[0047] Mercury intrusion pressure refers to the force required by the mercury intrusion porosimeter to force mercury into the orifice. Mercury intrusion volume refers to the volume of mercury entering the orifice. The pressure change point refers to the point where the mercury intrusion pressure changes.

[0048] by Figure 1 For example, the mercury injection device 20 applies pressure to the mercury, generating mercury injection pressure. As this pressure is applied, mercury enters the channel, creating an injection volume. Specifically, when the mercury injection device 20 applies pressure to the mercury, its pressure gauge can sense the mercury injection pressure. Then, the mercury injection device 20 can calculate the injection volume based on the mercury injection pressure. That is, each mercury injection pressure corresponds to a specific injection volume.

[0049] Understandably, due to the properties of mercury, the higher the mercury intrusion pressure, the larger the volume of mercury entering the pore. Therefore, as mercury enters the channel, the mercury intrusion pressure continuously increases, and the points where the mercury intrusion pressure changes are called pressure change points. There are multiple pressure change points from the moment mercury enters the channel until it completely permeates it. Therefore, the control device can acquire the mercury intrusion pressure at at least two pressure change points, as well as the corresponding mercury volume entering the pore.

[0050] Step S220: Determine the connectivity coefficient of the channel based on the first energy conservation formula, the second energy conservation formula, the mercury injection pressure, and the mercury injection volume.

[0051] The connectivity coefficient of a channel is used to evaluate the degree of connectivity of channels with a void structure. For example... Figure 1 As shown, assuming that each channel can be wetted by fluid, the connectivity coefficient of the channels in the rock under test is 1, indicating that the channels in the rock under test are completely connected.

[0052] The first law of conservation of energy states that the work required for mercury to enter the channel is equal to the sum of the pressure work done by the pressure applied to the mercury and the volume work done by the volume of mercury entering the channel.

[0053] For example, the first energy conservation formula (1) is shown below:

[0054] dW=PdV+VdP(1)

[0055] Where dW represents the work required for mercury to enter the channel, P represents the mercury injection pressure, V represents the volume of mercury entering, PdV represents the volume work of the mercury entering volume, the volume work represents the work done when the mercury entering volume changes, and VdP represents the pressure work of the mercury injection pressure, the pressure work represents the work done when the mercury injection pressure changes.

[0056] The second energy conservation formula states that the work required for mercury to enter the channel is equal to the sum of the surface energy generated by the mercury and the channel and the interfacial energy generated by the mercury and the air.

[0057] For example, the second energy conservation formula (2) is shown below:

[0058] dW=σd(A sl -A sv )+σdS(2)

[0059] The difference from formula (1) is that σ represents the mercury interfacial tension, and A sl This represents the contact area between the mercury and the wall of the channel. A sv The area represents the contact area between liquid mercury and mercury vapor, and S represents the interfacial area between mercury vapor and liquid mercury.

[0060] Since mercury and rock are non-wetting, formula (2) can be transformed into formula (3) according to Young's equation. That is, formula (3) is the second energy conservation formula.

[0061] dW=σdA+σdS(3)

[0062] Among them, A and A slThe meanings are consistent, both representing the contact area between mercury and the wall of the pore. The difference from formula (1) is that σdA represents the increased surface energy when mercury spreads on the wall of the pore. In this embodiment, σdA is simply referred to as the surface energy generated by mercury and the pore. σdS represents the interfacial energy possessed by the curved interface at the liquid mercury-mercury vapor interface. It can be understood that the curved interface refers to the interface where mercury contacts air; therefore, in this embodiment, σdS is simply referred to as the interfacial energy generated by mercury and air.

[0063] Understandably, based on formulas (1) and (3), term elimination is performed to obtain a data model that preprocesses the mercury intrusion pressure and the mercury inlet volume (i.e., the variables in the data model are the mercury intrusion pressure and the mercury inlet volume). Next, the mercury intrusion pressure and the mercury inlet volume are obtained and input into the data model, and the processed mercury intrusion pressure and the mercury inlet volume are output. The connectivity coefficient of the channel can be calculated based on the processed mercury intrusion pressure and the mercury inlet volume.

[0064] Understandably, in the above technical solution, when mercury enters the porous pores of the rock to be evaluated, the mercury intrusion pressure at at least two pressure change points and the corresponding mercury intrusion volume are obtained. The connectivity coefficient of the pores in the rock to be evaluated is then obtained based on the mercury intrusion pressure, the mercury intrusion volume, the first energy conservation formula, and the second energy conservation formula, to assess the degree of connectivity of the pores in the rock. By combining the two energy conservation formulas to process the mercury intrusion pressure and the mercury intrusion volume, the connectivity coefficient obtained from the processed mercury intrusion pressure and mercury intrusion volume becomes more accurate, leading to a more accurate assessment of the degree of connectivity of the pores in the rock.

[0065] Please see Figure 4 In some embodiments, step S220: determining the connectivity coefficient of the channel based on the first energy conservation formula, the second energy conservation formula, the mercury injection pressure, and the mercury injection volume includes: constructing a slope model of the channel in the form of a pore structure based on the first energy conservation formula and the second energy conservation formula; then, inputting the mercury injection pressure and the mercury injection volume into the slope model, outputting a set of discrete slope points, and finally calculating the connectivity coefficient of the channel based on the set of discrete slope points.

[0066] Specifically, it includes the following steps:

[0067] Step S410: Based on the principle of capillary bundle equivalence, the equivalent relationship between surface energy and interface energy in the second energy conservation formula is transformed to obtain the relationship between mercury intrusion pressure and mercury ingress volume, thus obtaining the third energy conservation formula.

[0068] The capillary bundle equivalence assumption principle refers to the analogy of a porous structure of channels to multiple capillaries of equal diameter with varying cross-sections and rough surfaces. Reservoir rocks can be viewed as a multidimensional, interconnected capillary network. Therefore, the capillary bundle model can be used to simplify the capillary network into a model composed of parallel combinations of capillaries of different sizes.

[0069] Based on the principle of capillary bundle equivalence, after the pores are equivalent to multiple capillaries with approximately equal diameters, the sum of the volumes of all pores in the rock to be evaluated is given by formula (4), and the sum of the areas of the inner surfaces of all pores is given by formulas (5) and (6).

[0070]

[0071] Where V represents the mercury injection volume, and from the perspective of the channel being filled with mercury, V can also represent the sum of the volumes of all channels. π represents pi, r represents the channel radius corresponding to the mercury injection pressure, and the corresponding channel radius can be calculated from the mercury injection pressure sensed by the pressure gauge. N(r) represents the number of channels with a channel radius of r, L represents the length of the channel, and dr represents the differential radius r.

[0072]

[0073] The difference between A and formula (4) is that A represents the contact area between mercury and the wall of the channel. From the perspective of mercury filling the channel, A can also be expressed as the sum of the areas of the inner surfaces of all channels.

[0074] S=2πr 2 N(r)(6)

[0075] The difference between this formula and formula (4) is that S represents the sum of the areas of the inner surfaces of all the channels.

[0076] It is understandable that formulas (5) and (6) use different methods to calculate the sum of the areas of the inner surfaces of all the channels.

[0077] At the same time, the relationship between mercury injection pressure and pore radius is combined (7).

[0078]

[0079] By combining formulas (4), (5), (6) and (7), and according to the definitions of each variable in the formulas, the second energy conservation formula (2) can be transformed into the third energy conservation formula (8).

[0080]

[0081] It is understandable that formula (8) transforms the equivalent relationship between surface energy σdA and interface energy σdS in the second energy conservation formula to obtain the relationship between mercury intrusion pressure and mercury intrusion volume.

[0082] Step S420: Based on the third energy conservation formula and the first energy conservation formula, construct a hyperbolic model of the channel.

[0083] Specifically, based on the principle of energy conservation, since the work dW required by mercury is the same in the first energy conservation formula (1) and the second energy conservation formula (3), the required work dW and the mercury interfacial tension σ can be eliminated to obtain formula (9):

[0084]

[0085] As can be seen from formula (9), the rate of change of the interface area S between mercury vapor and liquid mercury with the contact area A between mercury and the wall of the pore is equal to the slope of the tangent line of the mercury pressure curve under a double logarithmic coordinate system.

[0086] Based on formula (9) and the third energy conservation formula (8), a hyperbolic model (10) with mercury injection pressure and mercury injection volume as variables can be obtained.

[0087]

[0088] Understandably, the hyperbolic model (10) includes formulas that can characterize mercury intrusion curves. And the formula that can characterize the correlation curve Mercury intrusion porosimetry (MIP) curves characterize the relationship between the mercury intrusion pressure P and the mercury injection volume V. Correlation curves characterize the relationship between the mercury intrusion pressure P and the mercury injection volume V, derived from the conversion of surface energy σdA and interfacial energy σdS.

[0089] Step S430: Obtain the slope model based on the logarithm of the hyperbola model.

[0090] It is understandable that the hyperbolic model includes the mercury intrusion porosimetry curve and the correlation curve. Since the mercury intrusion porosimetry curve can characterize the relationship between the mercury intrusion pressure P and the mercury intrusion volume V, and the correlation curve characterizes the relationship between the mercury intrusion pressure P obtained from the conversion of surface energy σdA and interfacial energy σdS and the mercury intrusion volume V, the trends of the mercury intrusion porosimetry curve and the correlation curve should be approximate. In order to facilitate the analysis of the trend, the logarithm of the hyperbolic model (10) is taken to obtain formula (11).

[0091]

[0092] Formula (11) can be simplified to obtain formula (12).

[0093] logk2=-logk1+C(12)

[0094] Where k2 represents the slope of the first tangent line at a point on the double logarithmic mercury injection curve, and k1 represents the slope of the second tangent line at a point on the semi-logarithmic curve of the reciprocal mercury injection pressure and the injected mercury volume. It can be understood that the semi-logarithmic curve of the reciprocal mercury injection pressure and the injected mercury volume refers to the correlation curve of the embodiments of this application. C represents a constant.

[0095] Based on formulas (11) and (12), a slope model can be constructed, which includes a first slope model (13) and a second slope model (14).

[0096]

[0097] Where, k 2i This represents the slope of the tangent line corresponding to the i-th pressure change point on the double logarithmic mercury pressure curve.

[0098] P i+1 P represents the mercury intrusion pressure corresponding to the (i+1)th pressure change point. i-1 V represents the mercury intrusion pressure corresponding to the (i-1)th pressure change point. i+1 P represents the mercury inlet volume corresponding to the (i+1)th pressure change point. i-1 This represents the mercury inlet volume corresponding to the (i-1)th pressure change point.

[0099]

[0100] The difference from formula (13) is that k 1i The slope of the tangent line at the i-th pressure change point under the semi-logarithmic curve (i.e., the correlation curve) representing the reciprocal of the mercury injection pressure and the volume of mercury injected.

[0101] Under ideal conditions, when the connectivity of the porous structure is 100%, the equation (12) holds true, meaning the slopes of the mercury intrusion pressure curve and the correlation curve are linearly correlated. However, in the actual porous structure of rocks, the connectivity is not 100%, which deviates from the ideal state. The correlation between the two curves also changes accordingly. Therefore, the actual mercury intrusion pressure and mercury ingress volume are input into the slope model (including the first slope model (13) and the second slope model (14)) for preprocessing, and the preprocessed mercury intrusion pressure and mercury ingress volume are output. Based on the connectivity coefficient obtained from the preprocessed mercury intrusion pressure and mercury ingress volume, the connectivity (degree of connectivity) of the porous structure can be quantitatively characterized.

[0102] Step S440: Input the mercury pressure and mercury injection volume at at least two pressure change points into the slope model, and output the discrete point set of the slope.

[0103] Input the mercury injection pressure at at least two pressure change points and the mercury injection volume corresponding to the mercury injection pressure into the first tangent slope model (13), and output the first discrete point set {(V i ,p i That is, k 2i ={(V i ,p i )}.

[0104] Input the mercury injection pressure at at least two pressure change points and the mercury injection volume corresponding to the mercury injection pressure into the second tangent slope model (14), and output the second discrete point set {(V i ,p i That is, k 1i ={(V i ,p i )}.

[0105] It is understandable that the first discrete point set {(V i ,p i The second discrete point set {(V)} represents the set of mercury injection pressures preprocessed by the first tangent slope model and the corresponding mercury injection volumes, reflecting the relationship between mercury injection pressures and mercury injection volumes in the first tangent slope model. i ,p i )} is the set of mercury intrusion pressures after preprocessing by the second tangent slope model and the mercury intrusion volume corresponding to the mercury intrusion pressures, reflecting the relationship between mercury intrusion pressures and mercury intrusion volumes in the second tangent slope model.

[0106] Step S450: Calculate the connectivity coefficient of the channel based on the discrete point set of the slope.

[0107] Specifically, the connectivity coefficient of the channel is obtained based on the first discrete point set and the second discrete point set. For example, the formula (15) for determining the connectivity coefficient is as follows:

[0108]

[0109] Where d represents the connectivity coefficient, k 2i Let k represent the second discrete point set. 2i Let represent the first discrete point set.

[0110] This represents the average slope of the tangent lines at all points under the double logarithmic mercury intrusion curve, that is, This represents the average value of the first discrete point set. This represents the average slope of the tangent lines at all points on the semi-logarithmic curve of the reciprocal of the mercury injection pressure versus the amount of mercury injected, that is, This represents the average value of the second discrete point set. It can be understood that formula (15) indicates that the absolute value of the covariance between the first and second discrete point sets is the connectivity coefficient of the porous structure.

[0111] In some embodiments, the connectivity coefficient of the channel is within a preset range, which is calculated based on a preset J-function curve.

[0112] After obtaining the connectivity coefficients, a preset range can be calculated using a preset J-function curve. The slope model is then optimized based on this preset range to ensure that the connectivity coefficients output by the optimized slope model fall within the preset range. For example, a series of standard slopes are calculated based on the preset J-function curve, and standard connectivity coefficients are calculated based on these standard slopes. Using the standard connectivity coefficients as a benchmark, a range is selected, which is the preset range, for example, from 0.8 to 1.

[0113] The connectivity coefficients obtained by the connectivity evaluation method of this application are verified through the following experimental example.

[0114] Experimental preparation: Fourteen rocks to be evaluated were prepared. These 14 rocks came from the same stratum in a heterogeneous carbonate reservoir in an oilfield. The reservoir has complex geological conditions, diverse sedimentary and diagenetic processes, and strong heterogeneity.

[0115] The well names for the 14 rocks to be evaluated are W34, W110, W67, W60, W40, W104, W13, W31, W96, W18, W93, W82, and W50. The first value calculated based on porosity for each rock to be evaluated is approximately the same as the second value calculated based on permeability (the difference between the first and second values ​​can be preset).

[0116] Experimental method: The control device performs the following steps:

[0117] a1: Control the mercury injection device to inject mercury into each rock to be evaluated.

[0118] a2: Obtain the mercury intrusion pressure and mercury injection volume for each rock to be evaluated at at least two pressure change points.

[0119] a3: Input the mercury injection pressure and mercury injection volume from step a2 into the slope model, and output the discrete point set of the slope.

[0120] a4: Based on the slope discrete point set from step a3, calculate the connectivity coefficient of each rock to be evaluated, resulting in the connectivity coefficients of 14 rocks to be evaluated.

[0121] The connectivity coefficients of the 14 rocks to be evaluated are shown in Table 1 below.

[0122] Table 1. Connectivity Coefficient Results

[0123] well name Connectivity W34 1 W110 0.9966 W67 0.995 W60 0.9895 W40 0.9854 W104 0.9678 W13 0.9677 W31 0.9511 W96 0.9445 W18 0.9441 W93 0.9391 W82 0.904 W50 0.8666

[0124] Understandably, when porosity and permeability are similar, the closer the connectivity coefficient is to 1, the more accurate the evaluation of connectivity. The connectivity coefficients of the 14 rocks to be evaluated in Table 1 are all close to 1, indicating that the connectivity evaluation method of this application is accurate in evaluating the connectivity of pore-like channels in the rocks to be evaluated.

[0125] Next, the control device performs the following steps:

[0126] b1: Obtain the porosity and permeability of each rock to be evaluated.

[0127] b2: Obtain the mercury intrusion porosimetry curve based on the porosity and permeability from step b1.

[0128] b3: The mercury intrusion porosimetry curves obtained in step b2 are dimensionless to obtain the processed curves, resulting in 14 processed curves.

[0129] A schematic diagram of the 14 processed curves is shown below. Figure 5 As shown. Understandable. Figure 5 All 14 processed curves closely approximate the preset J-function curve. This demonstrates that the connectivity evaluation method of this application is accurate in evaluating the connectivity of porous structures in the rock to be evaluated.

[0130] Comparative Experiment: Following traditional evaluation methods, mercury intrusion pressure (MIP) and water saturation were obtained for 14 rocks to be evaluated. The MIP values ​​are shown in Table 2. Based on Table 2, MIP curves were plotted, and the results are as follows. Figure 6 As shown.

[0131] Table 2. Results of Mercury Intrusion Pressure and Water Saturation

[0132]

[0133]

[0134] Understandably, when evaluating the same 14 rocks, the mercury intrusion curves obtained by traditional evaluation methods vary greatly, with diverse curve shapes, making it difficult to determine the connectivity of pores with a void structure using conventional curve discrimination methods.

[0135] It is understood that the connectivity evaluation method in this application's embodiments processes the obtained mercury intrusion pressure and mercury injection volume using a slope model, and calculates the connectivity coefficient of the porous structure of the rock based on the processed mercury intrusion pressure and mercury injection volume. This method obtains fewer types of parameters, facilitating the calculation of the connectivity coefficient, and resulting in high accuracy of the connectivity coefficient.

[0136] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0137] Figure 7 This is a schematic diagram of the structure of an embodiment 1 of the rock channel connectivity evaluation device provided in this application; the device 30 can be integrated into the control device 10 in the above method embodiment, or it can be implemented by the control device 10 in the above method embodiment. Figure 7 As shown, the connectivity evaluation device 30 includes an acquisition module 31 and a calculation module 32.

[0138] The acquisition module 31 is used to acquire mercury entering the porous structure of the rock to be evaluated, the mercury intrusion pressure at at least two pressure change points, and the mercury intrusion volume corresponding to the mercury intrusion pressure.

[0139] The calculation module 32 is used to determine the connectivity coefficient of the pores based on the first energy conservation formula, the second energy conservation formula, the mercury injection pressure, and the mercury injection volume. The connectivity coefficient is used to evaluate the degree of connectivity of the pores in the form of a porous structure.

[0140] In some embodiments, the calculation module 32 is further configured to determine the connectivity coefficient of the channel based on the first energy conservation formula, the second energy conservation formula, the mercury injection pressure, and the mercury injection volume, including:

[0141] A slope model of a porous channel is constructed based on the first and second energy conservation formulas. The mercury injection pressure and the volume of mercury entering the channel are input into the slope model, and a set of discrete slope points is output. The connectivity coefficient of the channel is calculated based on the set of discrete slope points.

[0142] In some embodiments, the calculation module 32 is further configured to construct a hyperbolic model of a pore structure based on the first energy conservation formula and the second energy conservation formula, and calculate the slope model based on the logarithm of the hyperbolic model.

[0143] In some embodiments, the calculation module 32 is further configured to convert the equivalent relationship between surface energy and interface energy in the second energy conservation formula according to the capillary bundle equivalence assumption principle, obtain the change relationship between mercury injection pressure and mercury injection volume, and obtain the third energy conservation formula; based on the third energy conservation formula and the first energy conservation formula, construct a hyperbolic model of pore-structured channels.

[0144] In some embodiments, the calculation module 32 is further configured to input the mercury injection pressure and the mercury injection volume into a first tangent slope model to obtain a first discrete point set; input the mercury injection pressure and the mercury injection volume into a second tangent slope model to obtain a second discrete point set; and to obtain the connectivity coefficient of the channel based on the first discrete point set and the second discrete point set.

[0145] In some embodiments, the calculation module 32 is further configured to determine the absolute value of the covariance between the first discrete point set and the second discrete point set as the connectivity coefficient of the channel.

[0146] The connectivity evaluation device 30 provided in this embodiment is used to execute the technical solution in any of the aforementioned method embodiments. Its implementation principle and technical effect are similar, and will not be described again here.

[0147] Figure 8 This is a schematic diagram of the structure of a server provided in this application. Figure 8 As shown, the server 40 includes:

[0148] Processor 41, memory 42, and communication interface 43;

[0149] The memory 42 is used to store the executable instructions of the processor 41;

[0150] The processor 41 is configured to execute the server's technical solution in any of the foregoing method embodiments by executing the executable instructions.

[0151] Optionally, the memory 42 can be either standalone or integrated with the processor 41.

[0152] Optionally, when the memory 42 is a device independent of the processor 41, the server 40 may further include:

[0153] Bus 44, memory 42 and communication interface 43 are connected to processor 41 through bus 44 and complete communication with each other. Communication interface 43 is used to communicate with other devices.

[0154] Optionally, the communication interface 43 can be implemented using a transceiver. The communication interface is used to enable communication between the database access device and other devices (e.g., clients, read-write databases, and read-only databases). The memory may include random access memory (RAM) and may also include non-volatile memory, such as at least one disk drive.

[0155] Bus 44 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, only one thick line is used in the diagram, but this does not indicate that there is only one bus or one type of bus.

[0156] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0157] The server is used to execute the technical solution of the control device in any of the aforementioned method embodiments. Its implementation principle and technical effect are similar, and will not be described again here.

[0158] This application also provides a readable storage medium storing a computer program thereon, which, when executed by a processor, implements the technical solutions provided in any of the foregoing embodiments.

[0159] This application also provides a computer program product, including a computer program, which, when executed by a processor, is used to implement the technical solutions provided in any of the foregoing method embodiments.

[0160] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0161] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for evaluating the connectivity of rock pores, characterized in that, The method includes: Mercury entering a porous structure in a rock to be evaluated, mercury intrusion pressure at at least two pressure change points, and the mercury intrusion volume corresponding to the mercury intrusion pressure; The connectivity coefficient of the pores is determined based on the first energy conservation formula, the second energy conservation formula, the mercury injection pressure, and the mercury injection volume. The connectivity coefficient is used to evaluate the degree of connectivity of the pore-structured pores. Wherein, the first energy conservation formula means that the work required for mercury to enter the channel is equal to the sum of the pressure work of the mercury pressure applied to the mercury and the volume work of the mercury entering the channel, and the second energy conservation formula means that the work required for mercury to enter the channel is equal to the sum of the surface energy generated by the mercury and the channel and the interfacial energy generated by the mercury and the air.

2. The method according to claim 1, characterized in that, The determination of the connectivity coefficient of the channel based on the first energy conservation formula, the second energy conservation formula, the mercury injection pressure, and the mercury injection volume includes: A slope model for a porous structure is constructed based on the first energy conservation formula and the second energy conservation formula. The mercury injection pressure and the mercury injection volume are input into the slope model, and the slope discrete point set is output. The connectivity coefficient of the channel is calculated based on the discrete point set of the slope.

3. The method according to claim 2, characterized in that, The slope model for constructing a porous structure based on the first energy conservation formula and the second energy conservation formula includes: Based on the first energy conservation formula and the second energy conservation formula, a hyperbolic model of a porous channel is constructed. The hyperbolic model includes a mercury intrusion curve and a correlation curve. The mercury intrusion curve represents the relationship between the mercury intrusion pressure and the mercury intrusion volume, and the correlation curve represents the relationship between the mercury intrusion pressure and the mercury intrusion volume obtained from the conversion of surface energy and interface energy. The slope model is calculated based on the logarithm of the hyperbola model.

4. The method according to claim 3, characterized in that, The construction of a hyperbolic model of a porous channel based on the first energy conservation formula and the second energy conservation formula includes: Based on the principle of capillary bundle equivalence, the equivalent relationship between surface energy and interface energy in the second energy conservation formula is transformed to obtain the relationship between mercury injection pressure and mercury injection volume, thus obtaining the third energy conservation formula. Based on the third energy conservation formula and the first energy conservation formula, the hyperbola model with a porous structure is constructed.

5. The method according to claim 3, characterized in that, The slope model includes a first tangent slope model of the mercury intrusion curve and a second tangent slope model of the associated curve; The process of inputting the mercury injection pressure and the mercury injection volume into the slope model and outputting a discrete set of slope points includes: The mercury injection pressure and the mercury injection volume are input into the first tangent slope model to obtain the first discrete point set; The mercury injection pressure and the mercury injection volume are input into the second tangent slope model to obtain the second discrete point set; The process of calculating the connectivity coefficient of the channel based on the discrete point set of the slope includes: The connectivity coefficient of the channel is obtained based on the first discrete point set and the second discrete point set.

6. The method according to claim 5, characterized in that, The step of obtaining the connectivity coefficient of the channel based on the first discrete point set and the second discrete point set includes: The absolute value of the covariance between the first discrete point set and the second discrete point set is determined to be the connectivity coefficient of the channel.

7. The method according to any one of claims 1 to 6, characterized in that, The connectivity coefficient of the channel is within a preset range, which is calculated based on a preset J-function curve.

8. A device for evaluating the connectivity of rock channels, characterized in that, The connectivity evaluation device includes, The acquisition module is used to acquire mercury entering the porous structure of the rock to be evaluated, the mercury intrusion pressure at at least two pressure change points, and the mercury intrusion volume corresponding to the mercury intrusion pressure. The calculation module is used to determine the connectivity coefficient of the channel based on the first energy conservation formula, the second energy conservation formula, the mercury injection pressure, and the mercury injection volume. The connectivity coefficient is used to evaluate the degree of connectivity of the pore-structured channel.

9. A server, characterized in that, include: Processor, memory, communication interface; The memory is used to store the executable instructions of the processor; The processor is configured to perform the method of any one of claims 1 to 7 by executing the executable instructions.

10. A readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 7.

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