A shale oil multi-media cascade recovery rate evaluation method, device and equipment

Abstract

This article relates to the field of oil and gas field development engineering, and in particular to a method, device and equipment for evaluating the multi-media cascade recovery rate of shale oil. It includes arranging and combining the order of injecting multiple target media into saturated cores to obtain multiple initial imbibition recovery schemes; according to each initial imbibition recovery scheme, the corresponding saturated cores are sequentially subjected to imbibition recovery, and the imbibition recovery rates of the multiple target media in the initial imbibition recovery scheme are calculated; the multiple target media are arranged in order of imbibition recovery rate from small to large to form a recovery ladder of multiple target media; a target imbibition recovery scheme is generated according to the recovery ladder of multiple target media; and the imbibition recovery rate of the target imbibition recovery scheme is calculated to facilitate the determination of the final imbibition recovery scheme. The method of this article solves the problem that the existing technology cannot evaluate the multi-media cascade recovery rate, resulting in a low imbibition recovery rate of the actual oil reservoir.

Description

Technical Field

[0001] This article relates to the field of oil and gas field development engineering, and in particular to a shale oil multi-media cascade recovery rate evaluation method, device and equipment. Background Art

[0002] Shale reservoirs are dense and have low permeability, and shale oil has poor natural energy mobility. Shale oil production mainly relies on fracturing technology to transform the reservoir and injecting media to replace crude oil. Existing technologies all evaluate the recovery (enhanced oil recovery) effect of a single medium, and then specify an oil displacement plan based on the recovery effect of the medium. However, in actual applications, the recovery effect of a single medium is limited. To further improve the oil recovery rate, media with different recovery rates can also be injected into the rock formation. However, due to the differences in the interaction mechanisms and effects between different media and crude oil, and the interference of multiple media on the recovery rate after being implanted in the reservoir, the order of contact between the media and crude oil has a significant impact on the final recovery rate. Currently, there is no technical solution for evaluating the recovery rate of multiple media cascades.

[0003] There is an urgent need for a shale oil multi-media cascade recovery rate evaluation method to solve the problem that the existing technology cannot evaluate the multi-media cascade recovery rate. Summary of the Invention

[0004] To address the problem in the prior art of being unable to evaluate multi-media cascade recovery rates, the embodiments of this article provide a shale oil multi-media cascade recovery rate evaluation method, device, and equipment, which enable the evaluation of the recovery rates of multiple media with different injection sequences, thereby determining the optimal recovery plan based on the evaluation results.

[0005] In order to solve the above technical problems, the specific technical solutions of this article are as follows:

[0006] On the one hand, the embodiments of this invention provide a method for evaluating shale oil multi-media cascade recovery efficiency, comprising:

[0007] Arrange and combine the injection order of multiple target media into the saturated core to obtain multiple initial imbibition flooding schemes;

[0008] According to each initial imbibition flooding scheme, imbibition flooding is sequentially performed on the saturated core corresponding to the initial imbibition flooding scheme, and the imbibition recovery of multiple target media in the initial imbibition flooding scheme is calculated;

[0009] Arranging the plurality of target media in ascending order of the imbibition recovery rate to form a plurality of target media recovery steps;

[0010] generating a target imbibition flooding scheme according to the recovery steps of the plurality of target media, wherein the target imbibition flooding scheme includes the target media with the highest recovery step;

[0011] The imbibition recovery rate of the target imbibition flooding scheme is calculated, so as to determine a final imbibition flooding scheme from the target imbibition flooding scheme according to the imbibition recovery rate of the target imbibition flooding scheme.

[0012] Furthermore, arranging the plurality of target media in ascending order of the imbibition recovery rate to form a plurality of target media recovery steps further includes:

[0013] Determine the magnitude relationship of imbibition recovery rates of multiple target media in each initial imbibition flooding scheme;

[0014] The imbibition recovery rates of the plurality of target media are arranged in ascending order according to the size relationship, thereby obtaining the recovery enhancement steps.

[0015] Furthermore, performing imbibition flooding on the saturated core corresponding to the initial imbibition flooding scheme, and calculating the imbibition recovery rates of multiple target media in the initial imbibition flooding scheme further includes:

[0016] In accordance with the order of the multiple target media in the initial imbibition flooding scheme, the saturated core is subjected to imbibition flooding using each target medium in sequence, wherein after the imbibition flooding of the previous target medium reaches imbibition equilibrium, the nuclear magnetic resonance signal T2 spectrum of the saturated core is measured, and the saturated core is subjected to imbibition flooding again using the next target medium, until all target media in the initial imbibition flooding scheme have completed imbibition flooding of the saturated core;

[0017] The imbibition recovery rate of the target medium is calculated based on the nuclear magnetic signal T2 spectrum corresponding to the target medium, the nuclear magnetic signal T2 spectrum of the saturated core in a dried state before being saturated with crude oil, and the nuclear magnetic signal T2 spectrum of the saturated core when saturated with crude oil.

[0018] Furthermore, the formula for calculating the imbibition recovery rate of the target medium based on the nuclear magnetic signal T2 spectrum corresponding to the target medium, the nuclear magnetic signal T2 spectrum of the saturated core in the dried state before being saturated with crude oil, and the nuclear magnetic signal T2 spectrum of the saturated core when saturated with crude oil is:

[0019]

[0020] Among them, R 介质 It represents the imbibition recovery rate of the target medium, S 介质represents the T2 spectrum of the nuclear magnetic signal corresponding to the target medium, S1 represents the T2 spectrum of the nuclear magnetic signal of the saturated core in the dried state before being saturated with crude oil, and S2 represents the T2 spectrum of the nuclear magnetic signal of the saturated core when it is saturated with crude oil.

[0021] Furthermore, generating a target imbibition flooding scheme according to the multiple target medium recovery stages further includes:

[0022] According to the recovery steps, a predetermined number of target media are selected in sequence, and the order of injecting the selected target media into the target saturated core is determined according to the recovery steps corresponding to the selected target media to obtain a target imbibition flooding scheme.

[0023] Furthermore, calculating the imbibition recovery rate of the target imbibition flooding scheme further includes:

[0024] According to the target medium recovery steps in the target imbibition flooding scheme, the target medium is sequentially used to perform imbibition flooding on the target saturated core;

[0025] According to the results of the imbibition flooding, the imbibition recovery rate of the target imbibition flooding scheme is calculated.

[0026] Furthermore, according to the result of imbibition flooding, calculating the imbibition recovery factor of the target imbibition flooding scheme further includes:

[0027] After the target medium with the highest extraction step in the target imbibition flooding scheme has imbibed the target saturated core and reached imbibition equilibrium, measuring the nuclear magnetic signal T2 spectrum of the target saturated core at this time;

[0028] The imbibition recovery rate of the target medium is calculated based on the nuclear magnetic signal T2 spectrum of the target saturated core, the nuclear magnetic signal T2 spectrum of the target saturated core in a dried state before being saturated with crude oil, and the nuclear magnetic signal T2 spectrum of the target saturated core when saturated with crude oil.

[0029] On the other hand, the embodiment of this invention also provides a shale oil multi-media cascade recovery factor evaluation device, comprising:

[0030] An initial imbibition flooding scheme determination unit is used to arrange and combine the order of injecting multiple target media into the saturated core to obtain multiple initial imbibition flooding schemes;

[0031] an imbibition recovery calculation unit, configured to perform imbibition recovery on the saturated core corresponding to each initial imbibition recovery scheme in sequence according to the initial imbibition recovery scheme, and calculate the imbibition recovery of multiple target media in the initial imbibition recovery scheme;

[0032] An enhanced recovery step determination unit is used to arrange multiple target media in ascending order of the imbibition recovery rate to form enhanced recovery steps for the multiple target media;

[0033] a target imbibition flooding scheme generating unit, configured to generate a target imbibition flooding scheme according to the recovery steps of the plurality of target media, wherein the target imbibition flooding scheme includes the target media with the highest recovery step;

[0034] The imbibition recovery calculation unit is further used to calculate the imbibition recovery of the target imbibition recovery scheme, so as to determine a final imbibition recovery scheme from the target imbibition recovery schemes according to the imbibition recovery of the target imbibition recovery scheme.

[0035] Using the embodiments of this article, in order to accurately determine the imbibition recovery rate of multiple target media and avoid affecting the measurement accuracy if each target medium is imbibition-driven oil recovery separately due to the difference in properties of different saturated cores, the present invention first arranges and combines the order of injecting multiple target media into the saturated core to obtain multiple initial imbibition-driven oil recovery schemes, and then, according to each initial imbibition-driven oil recovery scheme, sequentially performs imbibition-driven oil recovery on the saturated core corresponding to the initial imbibition-driven oil recovery scheme, and calculates the imbibition recovery rate of multiple target media in each initial imbibition-driven oil recovery scheme, and then arranges the multiple target media in the order of imbibition recovery rate from small to large to form a recovery ladder of multiple target media, that is, the target medium. Compared with the method of performing imbibition recovery on each target medium separately, the imbibition recovery rate ranking solves the problem of low measurement accuracy caused by the difference in the properties of the saturated core. Then, a target imbibition recovery scheme is generated according to the obtained recovery step, and the imbibition recovery rate of the target recovery scheme is calculated. Finally, the final imbibition recovery scheme is determined according to the imbibition recovery rate of the target recovery scheme. The final imbibition recovery scheme is used to perform imbibition recovery on the actual oil reservoir, realizing the evaluation of the recovery rate of multiple media with different injection sequences, and thus determining the optimal recovery scheme based on the evaluation results. This solves the problem in the existing technology that the recovery rate of multiple media steps cannot be evaluated, resulting in low imbibition recovery rate of the actual oil reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of this article or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of this article. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 The figure shows a flow chart of a multi-media cascade recovery factor evaluation process for shale oil in an embodiment of this invention;

[0038] Figure 2 The embodiment of this invention shows the steps of arranging multiple target media in ascending order of imbibition recovery rate to form multiple target media recovery steps;

[0039] Figure 3 Shown are the steps for calculating the imbibition recovery rate of the target imbibition flooding scheme implemented in this paper;

[0040] Figure 4 The figure shows a schematic structural diagram of a shale oil multi-media cascade recovery factor evaluation device according to an embodiment of this invention;

[0041] Figure 5 The figure shows a schematic diagram of the structure of the computer device according to the embodiment of this article;

[0042] Figure 6 Shown is a bar chart comparing the recovery rates of heavy water, heavy water surfactant solution and CO2 in sequence in the examples of this article.

[0043]

Description of the accompanying drawings

[0044] 401. Initial imbibition flooding plan determination unit;

[0045] 402. Imbibition recovery calculation unit;

[0046] 403. Boosting step determination unit;

[0047] 404. Target imbibition flooding scheme generation unit;

[0048] 502. Computer equipment;

[0049] 504, processor;

[0050] 506. Memory;

[0051] 508, driving mechanism;

[0052] 510, input / output module;

[0053] 512. Input devices;

[0054] 514. Output device;

[0055] 516. Presentation equipment;

[0056] 518. Graphical User Interface;

[0057] 520, network interface;

[0058] 522, communication link;

[0059] 524. Communication bus. DETAILED DESCRIPTION

[0060] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of this document. Obviously, the embodiments described are only part of the embodiments of this document, not all of the embodiments. Based on the embodiments of this document, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this document.

[0061] It should be noted that the terms "first," "second," and the like in the specification and claims herein and in the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product, or device comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or devices.

[0062] In order to solve the problems existing in the prior art, the embodiments of this article provide a shale oil multi-media cascade recovery rate evaluation method, which realizes the evaluation of the recovery rate of multiple media with different injection sequences, and thus determines the optimal recovery plan based on the evaluation results. Figure 1 The figure shows a flow chart of a method for evaluating the multi-media cascade recovery rate of shale oil in an embodiment of this invention. This figure describes the process of rating the cascade recovery rate of multiple target media, but it can include more or fewer operating steps based on conventional or non-creative work. The order of steps listed in the embodiment is only one way of executing the order of many steps and does not represent the only execution order. When the system or device product is actually executed, it can be executed in sequence or in parallel according to the method shown in the embodiment or the accompanying drawings. Specifically, Figure 1 As shown, the method can be executed by a processor and may include:

[0063] Step 101: Arrange and combine the order of injecting multiple target media into the saturated core to obtain multiple initial imbibition flooding schemes;

[0064] Step 102: according to each initial imbibition flooding scheme, imbibition flooding is sequentially performed on the saturated core corresponding to the initial imbibition flooding scheme, and imbibition recovery factors of multiple target media in the initial imbibition flooding scheme are calculated;

[0065] Step 103: Arrange the target media in ascending order of the imbibition recovery rate to form a plurality of target media recovery steps;

[0066] Step 104: generating a target imbibition flooding scheme based on the recovery steps of the multiple target media, wherein the target imbibition flooding scheme includes the target media having the highest recovery step;

[0067] Step 105: Calculate the imbibition recovery rate of the target imbibition recovery scheme, so as to determine a final imbibition recovery scheme from the target imbibition recovery schemes according to the imbibition recovery rate of the target imbibition recovery scheme.

[0068] By using the embodiments of this invention, in order to accurately determine the imbibition recovery rate of multiple target media and avoid affecting the measurement accuracy if the imbibition recovery rate is performed on each target medium separately due to the difference in properties of different saturated cores, the present invention first arranges and combines the order of injecting multiple target media into the saturated core to obtain multiple initial imbibition recovery schemes, and then, according to each initial imbibition recovery scheme, sequentially performs imbibition recovery on the saturated core corresponding to the initial imbibition recovery scheme, calculates the imbibition recovery rate of multiple target media in each initial imbibition recovery scheme, and then calculates the imbibition recovery rate of multiple target media in each initial imbibition recovery scheme according to the imbibition recovery scheme. Multiple target media are arranged in ascending order of recovery to form a recovery ladder for multiple target media, that is, the imbibition recovery rate of the target media is sorted. Compared with the method of performing imbibition recovery on each target medium separately, this solves the problem of low measurement accuracy due to the difference in the properties of the saturated core. Then, a target imbibition recovery scheme is generated based on the obtained recovery ladder, and the imbibition recovery rate of the target recovery scheme is calculated. Finally, the final imbibition recovery scheme is determined based on the imbibition recovery rate of the target recovery scheme, and the actual reservoir is subjected to imbibition recovery using the final imbibition recovery scheme.

[0069] Through the method of the embodiment of this article, it is possible to evaluate the recovery rate of multiple media with different injection sequences, so as to determine the optimal recovery plan based on the evaluation results, thereby solving the problem that the existing technology cannot evaluate the multi-media step recovery rate, resulting in low imbibition recovery rate in actual oil reservoirs.

[0070] In the embodiment of this article, because the relationship between the imbibition recovery rates of multiple target media is unknown, if a target medium with a strong imbibition recovery rate is first used for imbibition recovery, and then a target medium with a weak imbibition recovery rate is used for imbibition recovery, the target medium with a weak imbibition recovery rate can no longer drive out crude oil, and the imbibition recovery rate of the target medium with a weak imbibition recovery rate cannot be determined. Therefore, the embodiment of this article arranges and combines the order in which multiple target media are injected into the saturated core to obtain multiple initial imbibition recovery schemes, and then, according to each initial imbibition recovery scheme, the corresponding saturated cores are sequentially subjected to imbibition recovery. In order to further improve the accuracy of determining the recovery step, multiple saturated cores are taken from the same target formation, thereby reducing the influence of the difference in the properties of the saturated cores on the determination of the recovery step; the imbibition recovery rates of multiple target media in each initial imbibition recovery scheme are calculated.

[0071] In the embodiments herein, after imbibition displacement of a saturated core by each target medium is performed, the relative dielectric constant of the saturated core is measured, and then the imbibition recovery rate of each target medium is calculated based on the relative dielectric constant.

[0072] After determining the imbibition recovery rate of each target medium in each initial imbibition recovery scheme, the multiple target media targeted by the permutation and combination are arranged in ascending order of imbibition recovery rate to form an enhanced recovery ladder for the multiple target media, i.e., the result of sorting the imbibition recovery rates of the multiple target media from smallest to largest. A target imbibition recovery scheme is then generated based on the enhanced recovery ladders of the multiple target media. In the embodiments herein, multiple target imbibition recovery schemes can be generated, but it should be noted that each target imbibition recovery scheme must include the target medium with the highest enhanced recovery ladder, because the target medium with the best enhanced recovery ladder has the strongest imbibition recovery capacity.

[0073] For example, the order of injecting the target medium: heavy water, heavy water surfactant solution and CO2 into the saturated core is arranged and combined to obtain The initial imbibition flooding schemes are (1) drying → saturated crude oil → heavy water imbibition → heavy water surfactant solution imbibition → CO2 huff and puff; (2) drying → saturated crude oil → heavy water imbibition → CO2 huff and puff → heavy water surfactant solution imbibition; (3) drying → saturated crude oil → heavy water surfactant solution imbibition → heavy water imbibition → CO2 huff and puff; (4) drying → saturated crude oil → heavy water surfactant solution imbibition → CO2 imbibition → heavy water imbibition; (5) drying → saturated crude oil → CO2 huff and puff → heavy water imbibition → heavy water surfactant solution imbibition; (6) drying → saturated crude oil → CO2 huff and puff → heavy water surfactant solution imbibition → heavy water imbibition. The imbibition recovery rates of heavy water, heavy water surfactant solution and CO2 in each initial imbibition flooding scheme are calculated, and then heavy water, heavy water surfactant solution and CO2 are arranged in ascending order of imbibition recovery rate, and the imbibition recovery rate of heavy water < imbibition recovery rate of heavy water surfactant solution < imbibition recovery rate of CO2 is obtained, thereby obtaining the recovery steps of heavy water, heavy water surfactant solution and CO2.

[0074] For example, in order to further improve the measurement accuracy, the same initial imbibition flooding scheme can be used to flood multiple cores, such as Figure 6 As shown, Figure 6The water imbibition recovery rate in the formula has the same meaning as the heavy water imbibition recovery rate, and the surfactant recovery rate has the same meaning as the heavy water surfactant solution recovery rate. Using the scheme (1) of drying → saturated crude oil → heavy water imbibition → heavy water surfactant solution imbibition → CO2 huff and puff, cores C2, C3, C4, and C5 were flooded. The results showed that the heavy water imbibition recovery rate was less than the heavy water surfactant solution recovery rate and less than the CO2 recovery rate. The recovery steps of heavy water, heavy water surfactant solution, and CO2 were stepped.

[0075] Then, a target imbibition flooding scheme is generated based on the heavy water, heavy water surfactant solution, and CO2 recovery steps. The target imbibition flooding schemes can be (1) drying → saturated crude oil → heavy water imbibition → heavy water surfactant solution imbibition → CO2 huff and puff; (2) drying → saturated crude oil → heavy water imbibition → CO2 huff and puff; (3) drying → saturated crude oil → heavy water surfactant solution imbibition → CO2 huff and puff; (4) drying → saturated crude oil → CO2 huff and puff. The imbibition recovery factor of each target imbibition flooding scheme is then calculated, and the final imbibition flooding scheme is determined from the target imbibition flooding schemes based on the imbibition recovery factor of the target imbibition flooding scheme. The “→” symbol indicates the imbibition flooding sequence. Each medium does not disappear after contact with crude oil. For example, when heavy water is first used for imbibition recovery, some oil is removed from the pores, and heavy water enters the pores, taking up the space previously occupied by the oil. At this point, when a heavy water surfactant solution is used for further imbibition, the heavy water surfactant solution must first pass through the heavy water before displacing the crude oil. This may cause the heavy water to act as a barrier, hindering the interaction between the heavy water surfactant solution molecules and the crude oil. Furthermore, when CO2 is added, the heavy water surfactant solution may also act as a barrier, hindering its effectiveness. Therefore, the total imbibition recovery rate (ultimate recovery rate) is highest when using a higher-grade (or even the highest-grade) medium directly. However, in some specific formations, due to limitations such as formation structure and environmental factors, direct imbibition recovery using the highest-grade target medium may yield higher recovery rates. A step-by-step imbibition recovery method, which follows a cascade of recovery steps, may also yield higher recovery rates. Therefore, it is necessary to calculate the imbibition recovery rate for each target imbibition recovery scenario and select the one with the highest imbibition recovery rate as the final imbibition recovery scenario. For example, if the imbibition recovery rate of scheme (4) drying → saturated crude oil → CO2 huff and puff is the highest, then scheme (4) drying → saturated crude oil → CO2 huff and puff can be used as the final imbibition flooding scheme, and the recovery rate is the highest when imbibition flooding is carried out on the actual oil reservoir using scheme (4) drying → saturated crude oil → CO2 huff and puff.

[0076] According to one embodiment of this invention, Figure 2 As shown, the step of arranging multiple target media in the order of the imbibition recovery rate from small to large to form multiple target media recovery steps further includes:

[0077] Step 201: determining the relationship between the imbibition recovery rates of multiple target media in each initial imbibition flooding scheme;

[0078] Step 202: Determine the order of imbibition recovery rates of multiple target media from small to large based on the size relationship, thereby obtaining the enhanced recovery steps.

[0079] In the embodiment of this article, because if the target medium with a higher imbibition recovery rate is first used for imbibition recovery, the target medium with a lower imbibition recovery rate will no longer be able to produce oil, therefore, the size relationship of the imbibition recovery rates of the multiple target media in each initial imbibition recovery scheme may only include which target medium has the largest imbibition recovery rate and which target medium has the same imbibition recovery rate (because these target media may no longer be able to produce oil). Then, according to the size relationship corresponding to these initial imbibition recovery schemes, the order of the imbibition recovery rates of the multiple target media from small to large is determined. For example, the initial imbibition recovery scheme A and the initial imbibition recovery scheme B both include target medium 1, target medium 2, and target medium 3. If the size relationship corresponding to the initial imbibition recovery scheme A is target medium 1 = target medium 3 < target medium 2, and the size relationship corresponding to the initial imbibition recovery scheme B is target medium 1 < target medium 3, then according to the size relationship corresponding to the initial imbibition recovery scheme A and the initial imbibition recovery scheme B, the final recovery ladder can be determined to be target medium 1 < target medium 3 < target medium 2.

[0080] According to one embodiment of the present invention, in order to improve the accuracy of calculating the imbibition recovery rate of the target medium, imbibition recovery is performed on the saturated core corresponding to the initial imbibition recovery scheme, and the imbibition recovery rates of multiple target media in the initial imbibition recovery scheme are calculated further including:

[0081] In accordance with the order of the multiple target media in the initial imbibition flooding scheme, the saturated core is subjected to imbibition flooding using each target medium in sequence, wherein after the imbibition flooding of the previous target medium reaches imbibition equilibrium, the nuclear magnetic resonance signal T2 spectrum of the saturated core is measured, and the saturated core is subjected to imbibition flooding again using the next target medium, until all target media in the initial imbibition flooding scheme have completed imbibition flooding of the saturated core;

[0082] The imbibition recovery rate of the target medium is calculated based on the nuclear magnetic signal T2 spectrum corresponding to the target medium, the nuclear magnetic signal T2 spectrum of the saturated core in a dried state before being saturated with crude oil, and the nuclear magnetic signal T2 spectrum of the saturated core when saturated with crude oil.

[0083] In the examples herein, imbibition flooding is performed on the saturated core according to the initial imbibition flooding scheme. After the imbibition flooding of the previous target medium reaches imbibition equilibrium, the nuclear magnetic signal T2 spectrum of the saturated core is measured, and the next target medium is replaced and the saturated core is again imbibition flooded. If the imbibition recovery rate of the next target medium is higher than that of the previous target medium, the next target medium can drive out the previous target medium and the remaining crude oil in the core. After imbibition equilibrium, the nuclear magnetic signal T2 spectrum of the saturated core is measured. Finally, the imbibition recovery rate of the target medium is calculated based on the nuclear magnetic signal T2 spectrum corresponding to each target medium, the nuclear magnetic signal T2 spectrum of the saturated core in the dried state before saturation with crude oil, and the nuclear magnetic signal T2 spectrum of the saturated core when saturated with crude oil.

[0084] It can be understood that the above method can accurately calculate the imbibition recovery rate of each target medium when the mass of crude oil in the saturated core is small and the mass of crude oil driven by each imbibition is also small.

[0085] According to one embodiment of the present invention, the formula for calculating the imbibition recovery rate of the target medium based on the nuclear magnetic signal T2 spectrum corresponding to the target medium, the nuclear magnetic signal T2 spectrum of the saturated core in the drying state before saturation with crude oil, and the nuclear magnetic signal T2 spectrum of the saturated core when saturated with crude oil is (1):

[0086]

[0087] Among them, R 介质 It represents the imbibition recovery rate of the target medium, S 介质 represents the T2 spectrum of the nuclear magnetic signal corresponding to the target medium, S1 represents the T2 spectrum of the nuclear magnetic signal of the saturated core in the dried state before being saturated with crude oil, and S2 represents the T2 spectrum of the nuclear magnetic signal of the saturated core when it is saturated with crude oil.

[0088] According to one embodiment of the present invention, generating a target imbibition flooding scheme according to the multiple target medium recovery stages further includes:

[0089] According to the recovery steps, a predetermined number of target media are selected in sequence, and the order of injecting the selected target media into the target saturated core is determined according to the recovery steps corresponding to the selected target media to obtain a target imbibition flooding scheme.

[0090] In the examples herein, the highest imbibition recovery rate is not achieved by sequentially applying imbibition flooding to all target media. Due to limitations in reservoir structure and formation factors, the highest imbibition recovery rate may be achieved by applying imbibition flooding to only a portion of the target media. Therefore, a predetermined number of target media (including the target medium with the highest recovery step) can be selected sequentially according to the recovery step. The order in which the selected target media are injected into the target saturated core is determined based on the recovery step corresponding to the selected target media to obtain a target imbibition flooding plan.

[0091] Then calculate the imbibition recovery rate of the target imbibition flooding scheme. According to one embodiment of this article, Figure 3 As shown, the step of calculating the imbibition recovery rate of the target imbibition flooding scheme further includes:

[0092] Step 301: performing imbibition flooding on the target saturated core using the target medium in sequence according to the target medium recovery steps in the target imbibition flooding scheme;

[0093] Step 302: Calculate the imbibition recovery rate of the target imbibition flooding scheme based on the result of the imbibition flooding.

[0094] In the examples herein, when the target imbibition flooding scheme is used for oil recovery, the target medium in the target imbibition flooding scheme is first used to perform imbibition flooding on the target saturated core, in accordance with the target medium's recovery steps, to obtain the imbibition flooding results. Based on the imbibition flooding results, the imbibition recovery factor of the target imbibition flooding scheme is then calculated.

[0095] For example, the imbibition recovery rate of the target imbibition flooding scheme can be calculated using the method shown in formula (1), and the imbibition flooding results obtained at this time include the nuclear magnetic signal T2 spectrum corresponding to each target medium. Specifically, according to one embodiment of this invention, based on the imbibition flooding results, calculating the imbibition recovery rate of the target imbibition flooding scheme further includes:

[0096] After the target medium with the highest extraction step in the target imbibition flooding scheme has imbibed the target saturated core and reached imbibition equilibrium, measuring the nuclear magnetic signal T2 spectrum of the target saturated core at this time;

[0097] The imbibition recovery rate of the target medium is calculated based on the nuclear magnetic signal T2 spectrum of the target saturated core, the nuclear magnetic signal T2 spectrum of the target saturated core in a dried state before being saturated with crude oil, and the nuclear magnetic signal T2 spectrum of the target saturated core when saturated with crude oil.

[0098] It can be understood that since the target medium with the highest recovery step in the target imbibition recovery scheme has the strongest imbibition recovery capacity, the imbibition recovery rate calculated using the T2 spectrum of the nuclear magnetic signal corresponding to the target medium with the highest recovery step can be used as the imbibition recovery rate of the target imbibition recovery scheme.

[0099] After obtaining the imbibition recovery rate of the target imbibition recovery scheme, the target imbibition recovery scheme with the highest imbibition recovery rate can be selected as the final imbibition recovery scheme to carry out imbibition recovery in the actual oil reservoir.

[0100] Based on the same inventive concept, the embodiment of this invention also provides a shale oil multi-media cascade recovery factor evaluation device, such as Figure 4 As shown, including:

[0101] An initial imbibition flooding scheme determining unit 401 is used to arrange and combine the order of injecting multiple target media into the saturated core to obtain multiple initial imbibition flooding schemes;

[0102] an imbibition recovery calculation unit 402 for performing imbibition recovery on the saturated core corresponding to each initial imbibition recovery scheme in sequence according to each initial imbibition recovery scheme, and calculating the imbibition recovery of multiple target media in the initial imbibition recovery scheme;

[0103] The recovery step determination unit 403 is configured to arrange the target media in ascending order of the imbibition recovery rate to form recovery steps for the target media;

[0104] A target imbibition flooding scheme generating unit 404 is configured to generate a target imbibition flooding scheme according to the recovery steps of the plurality of target media, wherein the target imbibition flooding scheme includes the target media with the highest recovery step;

[0105] The imbibition recovery calculation unit 402 is further used to calculate the imbibition recovery of the target imbibition recovery scheme, so as to determine a final imbibition recovery scheme from the target imbibition recovery schemes according to the imbibition recovery of the target imbibition recovery scheme.

[0106] Since the principle of solving the problem by the above device is similar to that of the above method, the implementation of the above device can refer to the implementation of the above method, and the repeated parts will not be repeated.

[0107] like Figure 5As shown, a computer device provided in an embodiment of this document is shown. The apparatus herein may be a computer device in this embodiment, executing the method described above. The computer device 502 may include one or more processors 504, such as one or more central processing units (CPUs), each of which may implement one or more hardware threads. The computer device 502 may also include any memory 506 for storing any type of information, such as code, settings, data, and the like. For example, and without limitation, the memory 506 may include any one or more combinations of the following: any type of RAM, any type of ROM, a flash memory device, a hard disk, an optical disk, and the like. More generally, any memory may use any technology to store information. Furthermore, any memory may provide volatile or non-volatile retention of information. Furthermore, any memory may represent a fixed or removable component of the computer device 502. In one embodiment, when the processor 504 executes associated instructions stored in any memory or combination of memories, the computer device 502 may perform any operation of the associated instructions. The computer device 502 also includes one or more drive mechanisms 508, such as a hard disk drive mechanism, an optical disk drive mechanism, and the like, for interacting with any memory.

[0108] The computer device 502 may also include an input / output module 510 (I / O) for receiving various inputs (via input devices 512) and for providing various outputs (via output devices 514). A specific output mechanism may include a presentation device 516 and an associated graphical user interface (GUI) 518. In other embodiments, the input / output module 510 (I / O), input devices 512, and output devices 514 may not be included, and the computer device 502 may simply be a computer device in a network. The computer device 502 may also include one or more network interfaces 520 for exchanging data with other devices via one or more communication links 522. One or more communication buses 524 couple the components described above together.

[0109] The communication link 522 may be implemented in any manner, for example, via a local area network, a wide area network (e.g., the Internet), a point-to-point connection, etc., or any combination thereof. The communication link 522 may include any combination of hardwired links, wireless links, routers, gateway functions, name servers, etc., governed by any protocol or combination of protocols.

[0110] Corresponding to Figure 1-Figure 3 In the method, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the above steps are executed.

[0111] The embodiment of the present invention also provides a computer readable instruction, wherein when the processor executes the instruction, the program causes the processor to execute the following Figure 1-Figure 3 The method shown.

[0112] It should be understood that in the various embodiments of this document, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this document.

[0113] It should also be understood that in the embodiments herein, the term "and / or" merely describes an association between associated objects, indicating that three possible relationships exist. For example, "A and / or B" could represent: A alone, A and B simultaneously, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0114] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the composition and steps of each example according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this document.

[0115] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0116] In the several embodiments provided herein, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices, or units, or can be an electrical, mechanical, or other form of connection.

[0117] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments herein.

[0118] In addition, the functional units in the various embodiments herein may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0119] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this article is essentially or the part that contributes to the existing technology, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of this article. The aforementioned storage medium includes: various media that can store program code, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0120] This article uses specific embodiments to illustrate the principles and implementation methods of this article. The description of the above embodiments is only used to help understand the methods and core ideas of this article. At the same time, for those skilled in the art, based on the ideas of this article, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation to this article.

Claims

1. A shale oil multi-media cascade recovery efficiency evaluation method, characterized in that: include: Arrange and combine the order of injecting multiple target media into the saturated core to obtain multiple initial imbibition flooding schemes; According to each initial imbibition flooding scheme, imbibition flooding is sequentially performed on the saturated core corresponding to the initial imbibition flooding scheme, and the imbibition recovery of multiple target media in the initial imbibition flooding scheme is calculated; Arranging the plurality of target media in ascending order of the imbibition recovery rate to form a plurality of target media recovery steps; generating a target imbibition flooding scheme according to the recovery steps of the plurality of target media, wherein the target imbibition flooding scheme includes the target media with the highest recovery step; Calculating the imbibition recovery of the target imbibition flooding scheme, so as to determine a final imbibition flooding scheme from the target imbibition flooding scheme according to the imbibition recovery of the target imbibition flooding scheme; Arranging the plurality of target media in ascending order of the imbibition recovery rate to form a plurality of target media recovery steps further includes: Determine the relationship between the imbibition recovery rates of multiple target media in each initial imbibition flooding scheme; Determine the order of imbibition recovery rates of multiple target media from small to large according to the size relationship, thereby obtaining the recovery enhancement steps; Performing imbibition flooding on the saturated core corresponding to the initial imbibition flooding scheme and calculating the imbibition recovery rates of multiple target media in the initial imbibition flooding scheme further includes: In accordance with the order of the multiple target media in the initial imbibition flooding scheme, the saturated core is subjected to imbibition flooding using each target medium in sequence, wherein after the imbibition flooding of the previous target medium reaches imbibition equilibrium, the nuclear magnetic resonance signal T2 spectrum of the saturated core is measured, and the saturated core is subjected to imbibition flooding again using the next target medium, until all target media in the initial imbibition flooding scheme have completed imbibition flooding of the saturated core; Calculating the imbibition recovery rate of the target medium based on the nuclear magnetic signal T2 spectrum corresponding to the target medium, the nuclear magnetic signal T2 spectrum of the saturated core in a dried state before being saturated with crude oil, and the nuclear magnetic signal T2 spectrum of the saturated core when saturated with crude oil; The formula for calculating the imbibition recovery rate of the target medium based on the nuclear magnetic signal T2 spectrum corresponding to the target medium, the nuclear magnetic signal T2 spectrum of the saturated core in the drying state before saturation with crude oil, and the nuclear magnetic signal T2 spectrum of the saturated core when saturated with crude oil is: ， in, R 介质 It represents the imbibition recovery rate of the target medium. S 介质 represents the T2 spectrum of the nuclear magnetic signal corresponding to the target medium, S 1 represents the T2 spectrum of the nuclear magnetic signal of the saturated core in the dried state before being saturated with crude oil. S 2 represents the T2 spectrum of the nuclear magnetic signal of the saturated core when it is saturated with crude oil.

2. The method according to claim 1, characterized in that Generating a target imbibition flooding scheme according to the multiple target medium recovery stages further includes: According to the recovery steps, a predetermined number of target media are selected in sequence, and the order of injecting the selected target media into the target saturated core is determined according to the recovery steps corresponding to the selected target media to obtain a target imbibition flooding scheme.

3. The method according to claim 2, characterized in that Calculating the imbibition recovery factor of the target imbibition flooding scheme further includes: According to the target medium recovery steps in the target imbibition flooding scheme, the target saturated core is sequentially flooded with the target medium using the target medium; According to the results of the imbibition flooding, the imbibition recovery factor of the target imbibition flooding scheme is calculated.

4. The method according to claim 3, characterized in that Calculating the imbibition recovery factor of the target imbibition flooding scheme according to the result of imbibition flooding further includes: After the target medium with the highest extraction step in the target imbibition flooding scheme has imbibed the target saturated core and reached imbibition equilibrium, measuring the nuclear magnetic signal T2 spectrum of the target saturated core at this time; The imbibition recovery rate of the target medium is calculated based on the nuclear magnetic signal T2 spectrum of the target saturated core, the nuclear magnetic signal T2 spectrum of the target saturated core in a dried state before being saturated with crude oil, and the nuclear magnetic signal T2 spectrum of the target saturated core when saturated with crude oil.

5. A shale oil multi-media cascade recovery factor evaluation device, characterized in that: include: An initial imbibition flooding scheme determination unit is used to arrange and combine the order of injecting multiple target media into the saturated core to obtain multiple initial imbibition flooding schemes; an imbibition recovery calculation unit, configured to perform imbibition recovery on the saturated core corresponding to each initial imbibition recovery scheme in sequence according to the initial imbibition recovery scheme, and calculate the imbibition recovery of multiple target media in the initial imbibition recovery scheme; An enhanced recovery step determination unit is used to arrange multiple target media in ascending order of the imbibition recovery rate to form enhanced recovery steps for the multiple target media; a target imbibition flooding scheme generating unit, configured to generate a target imbibition flooding scheme according to the recovery steps of the plurality of target media, wherein the target imbibition flooding scheme includes the target media with the highest recovery step; The imbibition recovery calculation unit is further used to calculate the imbibition recovery of the target imbibition recovery scheme, so as to determine a final imbibition recovery scheme from the target imbibition recovery scheme according to the imbibition recovery of the target imbibition recovery scheme; Arranging the plurality of target media in ascending order of the imbibition recovery rate to form a plurality of target media recovery steps further includes: Determine the relationship between the imbibition recovery rates of multiple target media in each initial imbibition flooding scheme; Determine the order of imbibition recovery rates of multiple target media from small to large according to the size relationship, thereby obtaining the recovery enhancement steps; Performing imbibition flooding on the saturated core corresponding to the initial imbibition flooding scheme and calculating the imbibition recovery rates of multiple target media in the initial imbibition flooding scheme further includes: In accordance with the order of the multiple target media in the initial imbibition flooding scheme, the saturated core is subjected to imbibition flooding using each target medium in sequence, wherein after the imbibition flooding of the previous target medium reaches imbibition equilibrium, the nuclear magnetic resonance signal T2 spectrum of the saturated core is measured, and the saturated core is subjected to imbibition flooding again using the next target medium, until all target media in the initial imbibition flooding scheme have completed imbibition flooding of the saturated core; Calculating the imbibition recovery rate of the target medium based on the nuclear magnetic signal T2 spectrum corresponding to the target medium, the nuclear magnetic signal T2 spectrum of the saturated core in a dried state before being saturated with crude oil, and the nuclear magnetic signal T2 spectrum of the saturated core when saturated with crude oil; The formula for calculating the imbibition recovery rate of the target medium based on the nuclear magnetic signal T2 spectrum corresponding to the target medium, the nuclear magnetic signal T2 spectrum of the saturated core in the drying state before saturation with crude oil, and the nuclear magnetic signal T2 spectrum of the saturated core when saturated with crude oil is: ， in, R 介质 It represents the imbibition recovery rate of the target medium. S 介质 represents the T2 spectrum of the nuclear magnetic signal corresponding to the target medium, S 1 represents the T2 spectrum of the nuclear magnetic signal of the saturated core in the dried state before being saturated with crude oil. S 2 represents the T2 spectrum of the nuclear magnetic signal of the saturated core when it is saturated with crude oil.

6. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 4 is implemented.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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