Method and device for determining saturation index of tight reservoir, electronic equipment and storage medium
By measuring the resistivity and effective conductive water saturation of the target core, the saturation index of the tight reservoir is calculated using the Archie formula, which solves the problem of overestimation in existing technologies and enables accurate assessment of tight reservoirs.
Patent Information
- Application Number
- CN202410587647.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-13
- Publication Date
- 2025-11-14
AI Technical Summary
Existing technologies using the core weighing method to calculate saturation in tight reservoirs tend to overestimate the saturation index, failing to accurately reflect the fluid distribution characteristics and conductivity within the core, resulting in inaccurate calculation results.
By measuring the saturated water resistivity, resistivity, and effective conductive water saturation of the target core, the saturation index is calculated using Archie's formula to eliminate the influence of water in disconnected pores and obtain the true saturation index.
The saturation index of the tight reservoir was accurately determined, eliminating the error caused by water in the pores that does not participate in electrical conductivity, and providing a true reflection of the state of the target core.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of oil exploration well detection technology, and in particular to a method, apparatus, electronic device and storage medium for determining the saturation index of tight reservoirs. Background Technology
[0002] In the field of oil exploration, Archie's formula is commonly used to determine the reservoir saturation index. However, tight reservoirs have low porosity and poor permeability. When reducing the water saturation of a core, the degree of water reduction within the pores at different locations in the core is uneven. Typically, there is a situation where one end of the core has high water saturation while the other end has low water saturation. The method of determining water saturation by core weighing reflects the total water saturation of the core and cannot reflect the fluid distribution characteristics within the core or the contribution of the fluid to the core's conductivity. When a core exhibits this situation, it indicates that some pore paths within the core are not connected. Measuring electrodes placed at both ends of the core cannot collect resistivity information from these disconnected pores. However, the conventional water saturation calculation method based on core weighing includes water from these disconnected pores, resulting in a higher water saturation level than the water saturation that contributes to the core's conductivity, thus leading to an overestimation of the saturation index. Summary of the Invention
[0003] This invention provides a method, apparatus, electronic device, and storage medium for determining the saturation index of tight reservoirs, in order to solve the problem that the saturation index calculated by conventional water saturation calculation methods based on core weighing is too high.
[0004] According to one aspect of the present invention, a method for determining the saturation index of a tight reservoir is provided, comprising:
[0005] Determine the saturated water resistivity of the target core, the resistivity of the target core, and the effective conductive water saturation of the target core;
[0006] The saturation index of the target core is determined based on the resistivity of the target core under saturated water state, the resistivity of the target core, and the effective conductive water saturation of the target core.
[0007] The saturation index of the target tight reservoir is determined based on the saturation index of the target core; the target core is a rock sample located within the target tight reservoir.
[0008] According to another aspect of the present invention, a device for determining the saturation index of a tight reservoir is provided, comprising:
[0009] The data determination module is used to determine the saturated water resistivity of the target core, the resistivity of the target core, and the effective conductive water saturation of the target core.
[0010] The target core saturation index determination module is used to determine the saturation index of the target core based on the saturated water resistivity of the target core, the resistivity of the target core, and the effective conductive water saturation of the target core.
[0011] The saturation index determination module for the target tight reservoir is used to determine the saturation index of the target tight reservoir based on the saturation index of the target core; the target core is a rock sample located within the target tight reservoir.
[0012] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:
[0013] At least one processor; and
[0014] A memory communicatively connected to the at least one processor; wherein,
[0015] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to perform the tight reservoir saturation index determination method according to any embodiment of the present invention.
[0016] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions for causing a processor to execute and implement the tight reservoir saturation index determination method according to any embodiment of the present invention.
[0017] The technical solution of this invention determines the saturation index of the target core by using the resistivity of the target core under saturated water state, the resistivity of the target core, and the effective conductive water saturation of the target core. Based on the saturation index of the target core, the saturation index of the target tight reservoir is determined. This method eliminates the water content in the pores of the target core that do not participate in conductivity, and eliminates the error caused by water in the pores that do not participate in conductivity, thereby obtaining a saturation index n that can reflect the true state of the target core.
[0018] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 A flowchart illustrating a method for determining the saturation index of a tight reservoir, as provided in an embodiment of the present invention;
[0021] Figure 2 A schematic diagram of the water saturation profile of a target core under 100% saturated water, provided as an embodiment of the present invention;
[0022] Figure 3 A schematic diagram illustrating the effective electrical conductivity saturation of a target core under centrifugal force of 50 psi, provided as an embodiment of the present invention;
[0023] Figure 4 A schematic diagram illustrating the effective electrical conductivity saturation of a target core under centrifugal force of 300 psi, provided as an embodiment of the present invention;
[0024] Figure 5 A schematic diagram illustrating the effective electrical conductivity saturation of a target core under centrifugal force of 800 psi, provided as an embodiment of the present invention;
[0025] Figure 6 A schematic diagram of the saturation index of a target rock core provided in an embodiment of the present invention;
[0026] Figure 7 This is a schematic diagram of a device for determining the saturation index of a tight reservoir provided in an embodiment of the present invention;
[0027] Figure 8 A schematic diagram of the structure of an electronic device for implementing the tight reservoir saturation index determination method of this invention. Detailed Implementation
[0028] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.
[0029] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention 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.
[0030] Figure 1 This is a flowchart illustrating a method for determining the saturation index of a tight reservoir according to an embodiment of the present invention. This embodiment is applicable to situations where the saturation index of a tight reservoir needs to be determined. This method can be executed by a tight reservoir saturation index determining device, which can be implemented in hardware and / or software. This device can be configured in any electronic device with network communication capabilities. Figure 1 As shown, the method includes:
[0031] S110. Determine the saturated water resistivity of the target core, the resistivity of the target core, and the effective conductive water saturation of the target core.
[0032] The resistivity of the target core in saturated water is the resistivity of the target core when it is completely saturated with water. The resistivity of the target core is used to characterize the conductivity of the target core, reflecting the charge conduction characteristics within the target core.
[0033] Furthermore, the target core resistivity is the core resistivity corresponding to the effective conductive water saturation of the target core.
[0034] The effective conductive water saturation of the target core is the saturation level of water within the target core that can actually conduct electricity.
[0035] The target core was energized, and the resistivity of the target core under saturated water was measured using measuring equipment. The target core was then centrifuged to measure the effective conductive water saturation.
[0036] Among them, the measuring equipment is a device capable of measuring resistivity.
[0037] Optionally, determine the resistivity of the target core under saturated water state and the target core resistivity, including steps A1-A3:
[0038] Step A1: Determine the target core within the target tight reservoir.
[0039] Target rock samples are collected from the target tight reservoir, and the target rock samples are processed to obtain the target rock core.
[0040] Optionally, the target core sample within the target tight reservoir is identified, including steps B1-B2:
[0041] Step B1: Obtain target rock samples from the target tight reservoir and process the target rock samples into target plunger-shaped cores.
[0042] The target plunger core is an elliptical cylindrical core.
[0043] Target rock samples were collected from the target tight reservoir, and the target rock samples were processed to obtain the target plunger-shaped rock core.
[0044] Step B2: The simulated formation aqueous solution is fused and absorbed with the target plunger core to obtain the plunger core to be treated.
[0045] The simulated formation water solution is obtained based on formation water analysis data, which includes at least the salinity of the formation water, and the formation water is groundwater within the target tight reservoir.
[0046] Furthermore, based on formation water analysis data, a formation water solution that closely resembles the actual formation water was prepared in the laboratory using chemical reagents.
[0047] The target plunger core is placed in the target plunger core evacuation and saturation device, and then a simulated formation aqueous solution is injected. Once the target plunger core has completely absorbed the simulated formation aqueous solution, the target plunger core that has completed the fusion absorption is taken as the plunger core to be processed.
[0048] Furthermore, complete absorption can ensure that the level of the simulated formation aqueous solution within the target plunger-shaped core evacuation saturation device no longer changes.
[0049] Furthermore, if the target plunger core completely absorbs the simulated formation aqueous solution, the simulated formation aqueous solution is continuously injected into the target plunger core saturation pump until the level of the simulated formation aqueous solution no longer changes.
[0050] Step B3: After continuously extracting air from the plunger-shaped core for a first preset time, continuously apply a reference pressure for a second preset time to obtain the target core.
[0051] The reference pressure is consistent with the pressure applied inside the target tight reservoir, the first preset time is the time for the vacuum pump to extract air, and the second preset time is the pressurization time set according to the actual pressurization state of the target tight reservoir.
[0052] The obtained plunger-shaped core to be processed is first evacuated by a vacuum pump for a first preset time, and then the target core is obtained by applying a reference pressure for a second preset time.
[0053] For example, the plunger-shaped rock core to be treated is placed in the plunger-shaped rock core evacuation and saturation device, and then a simulated formation aqueous solution is injected. The rock sample chamber, the simulated formation aqueous solution tank, and the pipeline of the plunger-shaped rock core evacuation and saturation device are evacuated for more than 12 hours using a vacuum pump. Then, a reference pressure is applied to the plunger-shaped rock core to be treated in the rock sample chamber of the plunger-shaped rock core evacuation and saturation device, and the pressure is kept stable for more than 12 hours to complete the saturation process of the target rock core and obtain the target rock core.
[0054] By using the above steps to process the target rock sample and determine the target core, the target core can be made to be infinitely close to the state of the target core in the target tight reservoir, which can improve the accuracy of the saturation index of the target core.
[0055] Step A2: Determine the saturated water resistivity of the target core using a digital bridge.
[0056] The digital bridge is an instrument for measuring the parameters of impedance elements. It obtains the resistivity of the target rock core under saturated water by measuring the target rock core under applied current.
[0057] An electric current is applied to the target core, and the resistivity of the target core under saturated water state is measured using a digital bridge.
[0058] For example, the surface of the target core is wiped clean of water, and the resistivity R0 of the target core in saturated water state is measured using the "two-electrode method". During the measurement process, it is ensured that the measuring electrode maintains good contact with the end face of the target core.
[0059] Furthermore, the "two-electrode method" involves loading electrodes at both ends of a rock core and measuring the resistivity of the target rock core under saturated water state using a digital bridge.
[0060] Step A3: Centrifuge the target core to obtain the target core resistivity.
[0061] The target core was centrifuged, and after centrifugation, the resistivity R of the target core was measured. t .
[0062] Furthermore, the centrifugation process described above is to reduce the water saturation of the target core.
[0063] For example, first, the centrifugal force is set to 50 psi in a centrifuge. After centrifuging the target core for 2 hours, the target core is taken out and the resistivity of the target core under the water saturation state is measured using the "two-polar method". This resistivity is taken as the resistivity of the target core.
[0064] Furthermore, using the above method, the target core resistivity was obtained at centrifugal forces of 300 psi and 800 psi, respectively.
[0065] Optionally, determine the effective electrical conductivity water saturation of the target core, including steps C1-C3:
[0066] Step C1: Determine the connectivity of the pores in the target core based on the target core.
[0067] The target rock core is measured using nuclear magnetic resonance (NMR) equipment, and the connectivity of the target rock core pores is determined based on the obtained NMR information.
[0068] Among them, nuclear magnetic resonance information reflects the location of water within the target core.
[0069] Furthermore, the target core sample measured by the nuclear magnetic resonance equipment was the target core sample that had been centrifuged in a centrifuge for 2 hours as described above.
[0070] Step C2: If the pore connectivity of the target core is connected, then the effective electrical conductivity and water saturation of the target core is constant.
[0071] The constant value is a pre-set value for the target core under 100% water saturation conditions. For example, the constant value can be calculated based on the formula for determining the effective electrical conductivity and water saturation of the target core, or it can be set according to actual needs.
[0072] If the pore connectivity of the target core is connected, it indicates that the target core is in a state of complete water saturation. Therefore, the effective conductive water saturation of the target core is set to a constant value.
[0073] Step C3: If the connectivity of the pores in the target core is not connected, determine the water saturation profile area of the connected pores in the target core, and determine the effective conductive water saturation of the target core based on the water saturation profile area of the connected pores in the target core and the water saturation profile area of the target core.
[0074] Wherein, the fully saturated water profile area of the target core is the water saturation profile area of the target core under 100% saturated water conditions, such as... Figure 2 As shown, the area enclosed by the thick solid line is the water saturation profile of the target core under 100% saturated water, and the area of the area enclosed by the thick solid line is the water saturation profile area of the target core under 100% saturated water.
[0075] If the pore connectivity of the target core is not connected, the connected pores of the target core are first determined based on the information obtained from the nuclear magnetic resonance equipment. The water saturation profile area of the connected pores of the target core is then determined based on the connected pores of the target core. Finally, the effective conductive water saturation of the target core is determined based on the water saturation profile area of the connected pores of the target core and the water saturation profile area of the target core.
[0076] Optionally, the process for determining the water saturation profile area of the connected pores in the target core includes steps D1-D3:
[0077] Step D1: If the pore connectivity of the target core is not connected, then establish a baseline based on the lowest point of the water saturation profile of the target core.
[0078] The water saturation profile of the target core is obtained based on nuclear magnetic resonance (NMR) information, which is generated by the NMR equipment based on the target core. The lowest point of the water saturation profile of the target core is the boundary point corresponding to the water saturation profile in the target core that is lower than other water saturation profiles. The baseline is a straight line parallel to the horizontal axis and passing through the lowest point of the water saturation profile of the target core.
[0079] If the target pores are not connected, the water saturation profile of the target core is obtained based on the NMR information. The lowest point of the water saturation profile of the target core is used as the reference point to establish a baseline parallel to the horizontal axis.
[0080] Step D2: The portion of the target core located below the baseline is considered as the connected pores of the target core.
[0081] The water in the pores of the target core above the baseline is not connected at both ends of the core, and this part of the water is invalid. However, the water in the pores of the target core below the baseline is connected within the target core, and this part of the water is effectively conductive. The part of the water that is effectively conductive is considered as the connected pores of the target core.
[0082] Step D3: Determine the water saturation profile area of the connected pores in the target core based on the connected pores in the target core.
[0083] The water saturation profile of the connected pores in the target core is determined based on the water saturation profile of the connected pores in the target core, and the area of the water saturation profile of the connected pores in the target core is calculated based on the water saturation profile of the connected pores in the target core.
[0084] Furthermore, the effective conductive water saturation of the target core is determined based on the water saturation profile area of the connected pores in the target core and the water saturation profile area of the target core.
[0085] Optionally, the effective electrical conductivity water saturation of the target core is expressed by the following formula:
[0086]
[0087] Wherein, S1 is the water saturation profile area of the connected pores in the target core; S2 is the profile area of the target core in a fully water-saturated state; S w The effective electrical conductivity and water saturation of the target core.
[0088] For example, if the pores of the target core are connected, the effective electrical conductivity water saturation of the target core can be obtained from the above formula as equal to 1.
[0089] For example, first, the centrifugal force is set to 50 psi in a centrifuge, and the target core is centrifuged for 2 hours. After processing, the target core is removed, and the water saturation profile of the target core is measured using nuclear magnetic resonance (NMR) equipment. NMR equipment can accurately collect information on the hydrogen nuclei of water within the target core. The NMR information on the target core profile reflects the location of water within the target core. If the pores of the target core are interconnected, the NMR signals at different locations in the target core will be basically consistent, and the water saturation profile will be basically consistent. Figure 2 As shown, the area enclosed by the thick solid line indicates that the water saturation profile of the target core is basically consistent, with no ineffective water portion. If the target core has unconnected pores, it will result in a high water saturation profile at one end and a low water saturation profile at the other. In this case, the lowest point of the target core's water saturation profile is used as the reference point to establish a baseline parallel to the horizontal axis. Above this baseline, the water in the pores of the target core is not connected at both ends of the target core; this part is ineffective water. Below the baseline, the water in the pores of the target core is connected within the target core and extends to both ends of the target core, capable of completely conducting electrical signals. This allows the measuring electrodes at both ends of the target core to collect the corresponding current signals; therefore, this part of the water is effectively conductive water. Figure 3 As shown, the area below the dashed line represents the effective conductive water portion, i.e., the connected pores of the target core, while the area above the dashed line represents the ineffective water portion. The core water-bearing profile is the target core water saturation profile. The water saturation profile area of the connected pores in the target core is calculated, and this calculated profile area is used as the water saturation profile of the connected pores in the target core. Based on the water saturation profile area of the connected pores in the target core and the profile area of the target core in a fully saturated water state, the effective conductive water saturation S of the target core is calculated. w .
[0090] Furthermore, using the above method, water saturation profiles of target cores with centrifugal forces of 300 psi and 800 psi were obtained, respectively, as follows: Figure 4 , Figure 5 As shown. At a centrifugal force of 300 psi, as... Figure 4As shown, the area below the dashed line represents the effective conductive water portion, i.e., the connected pores of the target core, while the area above the dashed line represents the ineffective water portion. At a centrifugal force of 800 psi, as... Figure 5 As shown, the area below the solid line represents the effective conductive water portion, i.e., the connected pores of the target rock core, while the area above the solid line represents the ineffective water portion.
[0091] S120. Determine the saturation index of the target core based on the resistivity of the target core under saturated water state, the resistivity of the target core, and the effective conductive water saturation of the target core.
[0092] The saturation index of the target core is calculated by substituting the target core resistivity, the target core resistivity, and the target effective conductive water saturation into Archie's formula.
[0093] Archie's formula is expressed as follows:
[0094]
[0095] Where R0 is the resistivity of the target core under saturated water state; R t The target core resistivity; S w Target effective conductivity water saturation; n is the saturation index; I is the resistivity increase rate index; b is the rock electrical parameter.
[0096] Optionally, the saturation index of the target core is determined based on the saturated water resistivity of the target core, the target core resistivity, and the target effective conductive water saturation, including steps E1-E2:
[0097] Step E1: Establish a functional relationship graph between the target core saturated water resistivity, the target core resistivity, and the target effective conductive water saturation.
[0098] Based on Archie's formula, the ratio of the target core saturated water resistivity to the target core resistivity is used as the ordinate, and the target effective conductive water saturation is used as the abscissa to establish a functional relationship graph between the target core saturated water resistivity, the target core resistivity, and the target effective conductive water saturation.
[0099] Step E2: Obtain the saturation index of the target core by fitting the function relationship graph.
[0100] The saturation index of the target core is obtained by fitting the function relationship graph.
[0101] For example, such as Figure 6 As shown, establish R t / R0 and S w Relationship diagram, R t / R0 is the ordinate, S wThe x-axis is used as the horizontal axis, and both the y-axis and x-axis use a logarithmic coordinate system. The saturation index n can be obtained by fitting the coordinates.
[0102] S130. Determine the saturation index of the target tight reservoir based on the saturation index of the target core.
[0103] The target core is a rock sample located within the target tight reservoir.
[0104] The target core is obtained from the target tight reservoir. Therefore, the target core and the target tight reservoir have the same geological structure and physical properties. Thus, the saturation index of the target core can be used as the saturation index of the target tight reservoir.
[0105] The technical solution of this embodiment determines the saturation index of the target core by using the resistivity of the target core under saturated water state, the resistivity of the target core, and the effective conductive water saturation of the target core. Based on the saturation index of the target core, the saturation index of the target tight reservoir is determined. This method eliminates the water content in the pores of the target core that do not participate in conductivity, and eliminates the error caused by water in the pores that do not participate in conductivity, thereby obtaining a saturation index n that can reflect the true state of the target core.
[0106] Figure 7 This is a schematic diagram of a device for determining the saturation index of a tight reservoir according to an embodiment of the present invention. This embodiment is applicable to situations where the saturation index of a tight reservoir is determined. The device can be implemented in hardware and / or software, and can be configured in any electronic device with network communication capabilities. Figure 7 As shown, the device includes: a data determination module 210, a target core saturation index determination module 220, and a target tight reservoir saturation index determination module 230, wherein:
[0107] Data determination module 210: used to determine the saturated water resistivity of the target core, the resistivity of the target core, and the effective conductive water saturation of the target core;
[0108] Target core saturation index determination module 220: used to determine the saturation index of the target core based on the saturated water state resistivity of the target core, the resistivity of the target core, and the effective conductive water saturation of the target core;
[0109] Target tight reservoir saturation index determination module 230: used to determine the saturation index of the target tight reservoir based on the saturation index of the target core; the target core is a rock sample located in the target tight reservoir.
[0110] Optionally, the data determination module 210 includes:
[0111] Target core identification unit: used to identify target cores within the target tight reservoir;
[0112] Saturated water resistivity determination unit: used to determine the saturated water resistivity of the target core using a digital bridge;
[0113] Core resistivity determination unit: used to centrifuge the target core to obtain the target core resistivity.
[0114] Optional, target core determination units include:
[0115] Target plunger core identification subunit: used to obtain target rock samples within the target tight reservoir and process the target rock samples into target plunger cores;
[0116] Sub-unit for determining the plunger core to be treated: used to fuse and absorb the simulated formation water solution with the target plunger core to obtain the plunger core to be treated; the simulated formation water solution is obtained based on formation water analysis data, which includes at least: the salinity of the formation water, and the formation water is groundwater in the target tight reservoir;
[0117] Target core determination subunit: used to continuously extract air from the plunger-shaped core to be processed for a first preset time, and then continuously apply a reference pressure for a second preset time to obtain the target core; the reference pressure is consistent with the pressure applied in the target tight reservoir, the first preset time is the time for the vacuum pump to extract air, and the second preset time is the pressurization time set according to the actual pressurization state of the target tight reservoir.
[0118] Optionally, the data determination module 210 includes:
[0119] Connectivity determination unit: used to determine the connectivity of the pores in the target core based on the target core;
[0120] Pore connectivity analysis unit: If the pore connectivity of the target core is connected, then the effective electrical conductivity and water saturation of the target core is constant; the constant value is a pre-set constant under 100% water saturation conditions of the target core.
[0121] Pore non-connectivity analysis unit: If the connectivity of the pores in the target core is not connected, then the water saturation profile area of the connected pores in the target core is determined. The effective conductive water saturation of the target core is determined based on the water saturation profile area of the connected pores in the target core and the water saturation profile area of the target core at 100% saturation. The water saturation profile area of the target core at 100% saturation is the water saturation profile area of the target core at 100% saturation.
[0122] Optional, pore disconnection analysis unit, including:
[0123] The baseline determination sub-unit is used to establish a baseline based on the lowest point of the water saturation profile of the target core if the pore connectivity of the target core is not connected. The water saturation profile of the target core is obtained based on NMR information, which is generated by the NMR equipment based on the target core. The lowest point of the water saturation profile of the target core is the boundary point corresponding to the water saturation profile in the target core that is lower than other water saturation profiles. The baseline is a straight line parallel to the horizontal axis and passing through the lowest point of the water saturation profile of the target core.
[0124] Connecting pores determination sub-unit: used to define the portion of the target core located below the baseline as the connecting pores of the target core;
[0125] Sub-unit for determining the water saturation profile area of connected pores: used to determine the water saturation profile area of connected pores in the target core based on the connected pores in the target core.
[0126] Optional, pore disconnection analysis element, specifically used for:
[0127] The effective electrical conductivity water saturation of the target core is expressed by the following formula:
[0128]
[0129] Wherein, S1 is the water saturation profile area of the connected pores in the target core; S2 is the profile area of the target core in a fully water-saturated state; S w The effective electrical conductivity and water saturation of the target core.
[0130] Optionally, the target core saturation index determination module 220 includes:
[0131] Function Relationship Graph Determination Unit: Used to establish a function relationship graph between the target core saturated water resistivity, the target core resistivity, and the target effective conductive water saturation.
[0132] The saturation index determination unit for the target core is used to obtain the saturation index of the target core by fitting the function relationship graph.
[0133] The tight reservoir saturation index determination device provided in the embodiments of the present invention can execute the tight reservoir saturation index determination method provided in any of the embodiments of the present invention, and has the corresponding functions and beneficial effects of executing the tight reservoir saturation index determination method. For detailed process, please refer to the relevant operations of the tight reservoir saturation index determination method in the foregoing embodiments.
[0134] Figure 8This is a schematic diagram of an electronic device for implementing the tight reservoir saturation index determination method according to embodiments of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.
[0135] like Figure 8 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.
[0136] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.
[0137] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the method for determining the saturation index of tight reservoirs.
[0138] In some embodiments, the tight reservoir saturation index determination method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or mounted on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the tight reservoir saturation index determination method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to perform the tight reservoir saturation index determination method by any other suitable means (e.g., by means of firmware).
[0139] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.
[0140] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.
[0141] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.
[0142] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).
[0143] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.
[0144] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.
[0145] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.
[0146] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.
Claims
1. A method for determining the saturation index of tight reservoirs, characterized in that, include: Determine the saturated water resistivity of the target core, the resistivity of the target core, and the effective conductive water saturation of the target core; The saturation index of the target core is determined based on the resistivity of the target core under saturated water state, the resistivity of the target core, and the effective conductive water saturation of the target core. The saturation index of the target tight reservoir is determined based on the saturation index of the target core; the target core is a rock sample located within the target tight reservoir.
2. The method according to claim 1, characterized in that, Determine the resistivity of the target core under saturated water state and the target core resistivity, including: Identify the target core sample within the target tight reservoir; The resistivity of the target rock core under saturated water state was determined using a digital bridge based on the target rock core. The target core was centrifuged to obtain its resistivity.
3. The method according to claim 2, characterized in that, Identifying target core samples within the target tight reservoir includes: Obtain target rock samples from the target tight reservoir and process the target rock samples into target plunger-shaped cores; The simulated formation aqueous solution is fused and absorbed with the target plunger core to obtain the plunger core to be treated; the simulated formation aqueous solution is obtained based on formation water analysis data, which includes at least the salinity of the formation water, and the formation water is groundwater in the target tight reservoir; After continuously extracting air from the plunger-shaped core to be processed for a first preset time, a reference pressure is continuously applied for a second preset time to obtain the target core; the reference pressure is consistent with the pressure applied in the target tight reservoir, the first preset time is the time for the vacuum pump to extract air, and the second preset time is the pressurization time set according to the actual pressurization state of the target tight reservoir.
4. The method according to claim 1, characterized in that, Determine the effective electrical conductivity and water saturation of the target core, including: The connectivity of the pores in the target core is determined based on the target core. If the pore connectivity of the target core is connected, then the effective electrical conductivity and water saturation of the target core is a constant value; the constant value is a pre-set constant value for the target core under 100% water saturation conditions. If the connectivity of the pores in the target core is not connected, then the water saturation profile area of the connected pores in the target core is determined. The effective conductive water saturation of the target core is determined based on the water saturation profile area of the connected pores in the target core and the water saturation profile area of the target core under 100% saturated water.
5. The method according to claim 4, characterized in that, The process of determining the water saturation profile area of the connected pores in the target core includes: If the pore connectivity of the target core is not connected, a baseline is established based on the lowest point of the water saturation profile of the target core. The water saturation profile of the target core is obtained based on NMR information, which is generated by the NMR equipment based on the target core. The lowest point of the water saturation profile of the target core is the boundary point corresponding to the water saturation profile in the target core that is lower than other water saturation profiles. The baseline is a straight line parallel to the horizontal axis and passing through the lowest point of the water saturation profile of the target core. The portion of the target core located below the baseline is considered as the connecting pores of the target core; The water saturation profile area of the target core's connected pores is determined based on the target core's connected pores.
6. The method according to claim 4, characterized in that, The effective electrical conductivity and water saturation of the target core are expressed by the following formula: Wherein, S1 is the water saturation profile area of the connected pores in the target core; S2 is the profile area of the target core in a fully water-saturated state; S w The effective electrical conductivity and water saturation of the target core.
7. The method according to claim 1, characterized in that, The saturation index of the target core is determined based on the saturated water resistivity of the target core, the resistivity of the target core, and the effective conductive water saturation of the target core, including: Establish a functional relationship graph between the target core resistivity under saturated water, the target core resistivity, and the target effective conductive water saturation. The saturation index of the target core is obtained by fitting the function relationship graph.
8. A device for determining the saturation index of tight reservoirs, characterized in that, include: The data determination module is used to determine the saturated water resistivity of the target core, the resistivity of the target core, and the effective conductive water saturation of the target core. The target core saturation index determination module is used to determine the saturation index of the target core based on the saturated water resistivity of the target core, the resistivity of the target core, and the effective conductive water saturation of the target core. The saturation index determination module for the target tight reservoir is used to determine the saturation index of the target tight reservoir based on the saturation index of the target core; the target core is a rock sample located within the target tight reservoir.
9. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the tight reservoir saturation index determination method according to any one of claims 1-7.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the method for determining the saturation index of a tight reservoir as described in any one of claims 1-7.