Method and device for determining residue accumulation coefficient of salt-cavern gas storage

Abstract

The invention discloses a method and device for determining the residue accumulation coefficient of a salt-cavern gas storage, and the method comprises the steps: determining the volume difference at the depth according to the volume data of two stages corresponding to the same depth in the sonar interpretation result of the salt-cavern gas storage; determining insoluble substance contents of stratums at different depths according to a gamma logging interpretation result; the original volume of the insoluble substance content of the salt-cavern gas storage and the volume of the expanded insoluble substance residue of the salt-cavern gas storage are obtained by multiplying the volume difference at different depths by the insoluble substance content and accumulating; and obtaining the insoluble substance residue accumulation coefficient of the salt-cavern gas storage according to the original volume of the insoluble substance content and the insoluble substance residue expansion volume.

Description

Technical Field

[0001] The present invention relates to the field of salt cavern underground gas storage cavity technology, and in particular to a method and device for determining the residue accumulation coefficient of a salt cavern underground gas storage. Background Art

[0002] Salt caverns are created by continuously injecting water into underground salt layers or salt domes under controlled conditions. The salt rock within these layers or domes dissolves in the water and returns to the surface as brine, creating a space beneath the surface. The formation of salt caverns occurs in stages, from bottom to top, determined primarily by the volume of the space created. After each stage is completed, the volume and morphology of the underground salt cavern are measured using sonar cavity measurement equipment. The sonar interpretation primarily includes the morphology and volume of cross-sections at different depths, ultimately resulting in a three-dimensional structural diagram of the salt cavern.

[0003] During the cavern formation process of water-soluble salt rock in salt cavern gas storage, insoluble residues from underground salt layers or salt domes fall and accumulate at the bottom of the salt cavern. This residue has a certain amount of pore space between it, causing the residue volume to expand. The residual accumulation coefficient, formed by the difference between this expansion and the original volume, plays a crucial role in optimizing the cavern formation parameters. Furthermore, the residual accumulation coefficient plays an important role in optimizing the utilization of the residual pore space.

[0004] Some technologies have certain limitations in calculating the residue accumulation coefficient. It is urgent to provide a method that can accurately calculate the residue accumulation coefficient to provide strong support for parameter optimization in the cavity making stage and expand the utilization of residue pore space. Summary of the Invention

[0005] The present application provides a method and apparatus for determining the residual accumulation coefficient of a salt-cavern gas storage reservoir. The method combines the sonar interpretation results and gamma-ray logging interpretation results of the salt-cavern gas storage reservoir to obtain a method that can accurately calculate the residual accumulation coefficient, providing strong support for parameter optimization in the cavity formation stage and expanding the utilization of residual pore space.

[0006] In a first aspect, the present application provides a method for determining a residue accumulation coefficient of a salt cavern gas storage, the method comprising:

[0007] Based on the volume data of the two stages corresponding to the same depth in the sonar interpretation results of the salt cavern gas storage, the volume difference at that depth is determined;

[0008] Determine the insoluble matter content at different depths based on the gamma logging interpretation results;

[0009] The original volume of the insoluble matter content of the salt cavern gas storage reservoir and the volume of the insoluble matter residue of the salt cavern gas storage reservoir after expansion are obtained by multiplying and accumulating the volume difference at different depths and the insoluble matter content;

[0010] The insoluble residue accumulation coefficient of the salt cavern gas storage is obtained according to the original volume of the insoluble matter content and the expanded volume of the insoluble residue.

[0011] In a second aspect, an embodiment of the present invention provides a device for determining the residual accumulation coefficient of a salt cavern gas storage reservoir, the device comprising: a memory and a processor; the memory is used to store a program for determining the residual accumulation coefficient of the salt cavern gas storage reservoir, and the processor is used to read and execute the program for determining the residual accumulation coefficient of the salt cavern gas storage reservoir, and perform any one of the methods described in the above embodiments.

[0012] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium having a data processing program stored thereon, and the data processing program is executed by a processor to perform the method for determining the residual accumulation coefficient of a salt cavern gas storage according to any one of the above embodiments.

[0013] Compared with the related art, the present application provides a method and device for determining the residue accumulation coefficient of a salt cavern gas storage reservoir, the method comprising: determining the volume difference at the depth based on the volume data of two stages corresponding to the same depth in the sonar interpretation results of the salt cavern gas storage reservoir; determining the insoluble matter content of the formation at different depths based on the gamma logging interpretation results; multiplying and accumulating the volume difference at different depths and the insoluble matter content to obtain the original volume of the insoluble matter content of the salt cavern gas storage reservoir and the volume after the expansion of the insoluble matter residue of the salt cavern gas storage reservoir; and obtaining the insoluble matter residue accumulation coefficient of the salt cavern gas storage reservoir based on the original volume of the insoluble matter content and the expanded volume of the insoluble residue. The present application combines the sonar interpretation results and gamma logging interpretation results of the salt cavern gas storage reservoir to obtain a method that can accurately calculate the residue accumulation coefficient, providing strong support for optimizing parameters in the cavity making stage and expanding the utilization of the residue pore space.

[0014] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. Other advantages of the present application can be realized and obtained by the solutions described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0016] Figure 1 This is a flow chart of a method for determining the residue accumulation coefficient of a salt cavern gas storage in an embodiment of the present application;

[0017] Figure 2Schematic diagram of a device for determining the residue accumulation coefficient of a salt cavern gas storage in an embodiment of the present application;

[0018] Figure 3 Schematic diagram of a method for determining a residue accumulation coefficient of a salt cavern gas storage in some exemplary embodiments. DETAILED DESCRIPTION

[0019] This application describes multiple embodiments, but this description is exemplary rather than restrictive, and it will be apparent to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described herein. Although many possible feature combinations are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0020] This application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features, and elements disclosed in this application may also be combined with any conventional features or elements to form a unique inventive solution defined by the claims. Any features or elements of any embodiment may also be combined with features or elements from other inventive solutions to form another unique inventive solution defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the appended claims and their equivalents, the embodiments are not subject to other limitations. In addition, various modifications and changes may be made within the scope of protection of the appended claims.

[0021] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps in the specific order described. As will be understood by those skilled in the art, other orders of steps are also possible. Therefore, the specific order of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to performing their steps in the order written, and those skilled in the art can readily understand that these orders can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0022] During the cavern formation process of water-soluble salt rock in a salt cavern gas storage facility, insoluble residue from underground salt layers or salt domes falls and accumulates at the bottom of the cavern. This trapped residue has interstitial spaces, causing it to expand. The ratio of the expanded volume of the accumulated insoluble residue to the original volume is the residue accumulation coefficient. For example, if the original volume of the residue is 5,000 cubic meters and the expanded volume is 8,000 cubic meters, the residue accumulation coefficient is 1.6.

[0023] First, the residue accumulation coefficient plays a very important role in optimizing the stage-by-stage cavitation parameters. After the sonar cavity interpretation is completed in the cavitation stage, the subsequent cavitation string insertion depth needs to be optimized and adjusted. Generally speaking, during the water-soluble cavitation process, the cavitation string insertion depth should be above the top of the residue to prevent the residue from entering and clogging the cavitation string. If the residue accumulation coefficient is too large, the predicted depth of the residue top surface will be too high, and the designed cavitation string insertion depth will be shallow, resulting in a reduced distance between the two ports and a lower brine concentration. If the residue accumulation coefficient is too small, the predicted depth of the residue top surface will be too low, and the designed cavitation string insertion depth will be too high, which will pose a risk of cavitation string clogging.

[0024] Secondly, the residual accumulation coefficient plays an important role in guiding the expansion of residual pore space utilization. The development and utilization of residual pore space is currently a hot topic in salt cavern gas storage research. After the water-dissolution of salt caverns is completed, a large amount of insoluble residue accumulates in the underground salt caverns. The residual accumulation coefficient can accurately predict the size of the residual pore space, providing a volume parameter reference for the subsequent expansion of salt cavern gas storage space.

[0025] There are currently two ways to determine the residue accumulation coefficient: the first is to conduct an indoor water solubility test on cores obtained from drilling, measure the volume of the expanded residue and the original volume of the residue, and calculate the volume ratio to obtain the residue accumulation coefficient; the second is to calculate it based on the relationship between the salt production of the cavity, the insoluble matter content, and the effective volume of the salt cavity. The specific relationship between the salt production of the cavity, the insoluble matter content, and the sonar volume of the salt cavity is as follows:

[0026] V 产盐量 ÷C 不溶物含量 =V 原始地层体积 Formula (1)

[0027] V 原始地层体积 ×(1-C 不溶物含量 )=V 不溶物残渣原始体积 Formula (2)

[0028] V 原始地层体积 - V 不溶物残渣原始体积 × R 残渣堆积系数 =V 声呐体积 Formula (3)

[0029] Where:

[0030] V 产盐量 is the volume of salt produced, in cubic meters;

[0031] V 原始地层体积 is the original formation volume before water dissolution, in cubic meters;

[0032] C 不溶物含量 It is the volume percentage of insoluble matter in a certain formation volume, with a dimension of 1;

[0033] V 不溶物残渣原始体积 is the original volume of the insoluble residue in cubic meters;

[0034] R 残渣堆积系数 It is the ratio of the expanded volume of the insoluble residue to the original volume of the insoluble residue, and its dimension is 1;

[0035] V 声呐体积 The volume of the salt cavity measured by sonar equipment, in cubic meters.

[0036] Both methods have limitations. The core sample size in the first method is relatively small, significantly different from the actual size of the residue in the underground salt cavity. The particle size of the residue samples in laboratory experiments is typically in the centimeter range, while the size of the residue accumulation in the underground salt cavity is in the meter range. Furthermore, laboratory experiments cannot effectively account for the compaction effect of the overlying strata, which also leads to poor measurement accuracy. The second method can only calculate the amount of salt returned to the surface based on the amount and concentration of brine produced. However, the brine remaining in the pore space of the underground salt cavity residue cannot be calculated, resulting in inaccurate salt production and large errors in the calculation of the residue accumulation coefficient.

[0037] In response to the problems existing in the above-mentioned method, the inventors of the present application proposed a method for calculating the residual accumulation coefficient by combining the sonar interpretation results and gamma logging interpretation results of salt cavern gas storage. This method can accurately calculate the residual accumulation coefficient, providing strong support for parameter optimization in the cavity creation stage and expanding the utilization of residual pore space.

[0038] The embodiment of the present invention provides a method for determining the residue accumulation coefficient of a salt cavern gas storage. Figure 1 As shown, the method includes steps S100-S130, which are specifically as follows:

[0039] S100: determining the volume difference at the same depth based on the volume data of two stages corresponding to the same depth in the sonar interpretation results of the salt cavern gas storage;

[0040] S110: Determine the insoluble matter content at different depths based on the gamma logging interpretation results;

[0041] S120: multiplying and accumulating the volume differences at different depths and the insoluble matter content to obtain an original volume S1 of the insoluble matter content of the salt cavern gas storage and an expanded volume S2 of the insoluble matter residue of the salt cavern gas storage;

[0042] S130: Obtaining an insoluble residue accumulation coefficient of the salt cavern gas storage according to the original volume of the insoluble content and the expanded volume of the insoluble residue.

[0043] In an exemplary embodiment, based on the volume data of two stages corresponding to the same depth in the sonar interpretation results of the salt cavern gas storage, the process of determining the volume difference at the depth is as follows:

[0044] Salt cavern gas storage is constructed in stages from bottom to top. Once the lower salt cavern has reached a certain volume, sonar measurement is performed. Subsequent cavern parameters are optimized and adjusted based on the sonar interpretation results. Sonar measurement involves lowering a measurement instrument from the cavern wellhead into the underground salt cavern. The instrument emits acoustic signals that are transmitted to surface data processing software, which uses time-of-flight ranging (TDF) to measure and interpret the cavern's shape and volume.

[0045] A single salt cavity requires multiple sonar measurements; generally, one sonar measurement is performed during each cavity formation phase. Randomly select two sonar interpretations to create a comparison table of salt cavity volume data from the two interpretations, as shown in Table 1. In Table 1, the sonar measurement for phase M occurs after the sonar measurement for phase N. The volume difference Δvi is then calculated by subtracting the volume data at the same depth. In this step, the volume Vi corresponding to the depth Hi in the subsequent phase M sonar interpretation is subtracted from the volume Vi corresponding to the same depth Hi in the previous phase N sonar interpretation. This calculation calculates the volume difference Δvi at the same depth in the two sonar interpretations, M and N.

[0046] Table 1

[0047]

[0048]

[0049] In an exemplary embodiment, determining the insoluble matter content at different depths based on the gamma logging interpretation results includes:

[0050] The first step is to determine the initial insoluble content at different depths based on the gamma logging interpretation results and the insoluble content calculation formula;

[0051] The insoluble matter content is calculated as follows:

[0052]

[0053] Where: C i 1 Hi The insoluble matter content at the depth of the formation, GR is H i Gamma value at formation depth, GR min is the natural gamma value of the sandstone layer, GR max is the natural gamma value of the mudstone layer.

[0054] The second step is to correct the initial insoluble matter content using a correction formula to obtain the insoluble matter content at different depths; as shown in Table 2, a schematic table of insoluble matter content calculation based on GR logging interpretation.

[0055] Wherein, the correction formula is:

[0056]

[0057] In the above formula, GCUR is the empirical coefficient related to the formation, C i H i Insoluble matter content C at formation depth i 1 .

[0058] In the above formula, GCUR is an empirical coefficient related to the formation, specifically:

[0059] If the age of the stratum is the Tertiary stratum or above, GCUR = 3.7;

[0060] If the age of the stratum is older than the Tertiary System, GCUR = 2.0.

[0061] Table 2

[0062]

[0063]

[0064] In an exemplary embodiment, the original volume of the insoluble content is:

[0065] S1=|∑CiΔvi|;

[0066] In the above formula, S1 is the original volume of insoluble matter, C i H i Insoluble matter content C at formation depth i 1 , Δvi is H i Volume difference at formation depth.

[0067] The expanded volume of the insoluble residue is:

[0068] S2=|∑CiΔvi|;

[0069] In the above formula, S2 is the expansion volume of the insoluble residue.

[0070] In an exemplary embodiment, the insoluble residue accumulation coefficient is:

[0071] δ = S1 / S2;

[0072] In the above formula, δ is the insoluble residue accumulation coefficient.

[0073] In this embodiment, the insoluble residue accumulation coefficient δ is obtained by dividing the expanded volume S2 of the insoluble residue by the original volume S1 of the insoluble residue.

[0074] The present invention has the following beneficial effects:

[0075] (1) The inversion method for calculating the residue accumulation coefficient is highly accurate. For example, during the 8th and 9th sonar interpretations of Well X at the XX gas storage facility, the residue accumulation coefficient was calculated to be 1.35 using this method. This result was then applied to the optimization design of the cavity formation parameters for the 10th phase. In the 10th phase sonar interpretation report, the measured residue accumulation depth was 1085m, which was completely consistent with the predicted residue accumulation depth of 1085m, effectively guiding on-site construction.

[0076] (2) Subsurface residues contain a large amount of pore space. The present invention uses the volume of the expanded residue accumulation and the original volume to inversely calculate the residue accumulation coefficient. After the salt cavity is dissolved in water, the original volume of the residue in the salt cavity can be calculated using forward modeling, and the pore space within the cavity can be obtained, laying the foundation for the subsequent expansion of underground gas storage space.

[0077] The embodiment of the present disclosure also provides a device for determining the accumulation coefficient of the residue in the salt cavern gas storage. Figure 2 As shown, the device includes: a memory 200 and a processor 210; the memory is used to store a program for determining the residual accumulation coefficient of the salt cavern gas storage, and the processor is used to read and execute the program for determining the residual accumulation coefficient of the salt cavern gas storage, and perform any one of the methods described in the above embodiments.

[0078] The present disclosure also provides a computer-readable storage medium having a data processing program stored thereon. The data processing program is used by a processor to execute the method for determining the residue accumulation coefficient of a salt cavern gas storage as described in any one of the above embodiments.

[0079] Example 1

[0080] This example shows a method for inverting the residue accumulation coefficient based on sonar cavity data of salt cavern gas storage. Figure 3 As shown:

[0081] Figure 3 middle:

[0082] 1 is the volume data of sonar measurement in stage N, vi;

[0083] 2 is the formation depth, Hi;

[0084] 3 is the insoluble matter content at different stratum depths, Ci;

[0085] 4 is the salt cavity morphology;

[0086] 5 is the volume ratio data of sonar measurement in stage M, ΔVi;

[0087] 6 is the volume difference between M and N sonar interpretations at the same depth interface, Δvi;

[0088] 7 is the original volume of insoluble residue, S1;

[0089] 8 is the expansion volume of the insoluble residue, S2;

[0090] 9 is the residue accumulation volume, δ.

[0091] exist Figure 3 In the schematic diagram of calculating the residue accumulation coefficient by inverting the sonar cavity measurement data shown in FIG, the specific calculation process is as follows:

[0092] The first step is to establish the volume data Vi and vi of the salt cavity from two sonar interpretations based on the sonar interpretation results, and obtain the volume difference Δvi of the cavity at different depths;

[0093] The second step is to calculate the insoluble matter content Ci at different depths Hi based on the GR logging interpretation;

[0094] The third step is to obtain the original volume S1 of the insoluble residue formed during the two sonar processes of the salt cavity and the volume S2 of the insoluble residue after expansion and accumulation according to the volume difference Δvi and the insoluble content;

[0095] Step 4: Calculate the ratio δ of the volume S2 of the insoluble residue after expansion and accumulation to the original volume S1 of the insoluble residue, which is the residue accumulation coefficient.

[0096] This example uses actual sonar data from underground salt caverns and well logging interpretation results to calculate the accumulation coefficient of the salt caverns at two different sonar interpretation stages, ultimately obtaining the residual accumulation coefficient. This method can effectively and accurately predict the residual accumulation coefficient, efficiently guiding cavern formation and expanding the utilization of residual pore space, making it suitable for a wide range of applications.

[0097] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As is well known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable, and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those skilled in the art that communication media generally embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. A method for determining the residue accumulation coefficient of a salt cavern gas storage, characterized in that: The method comprises: Based on the volume data of the two stages corresponding to the same depth in the sonar interpretation results of the salt cavern gas storage, the volume difference at that depth is determined; Determine the insoluble matter content at different depths based on the gamma logging interpretation results; The original volume of the insoluble matter content of the salt cavern gas storage reservoir and the volume of the insoluble matter residue of the salt cavern gas storage reservoir after expansion are obtained by multiplying and accumulating the volume difference at different depths and the insoluble matter content; The insoluble residue accumulation coefficient of the salt cavern gas storage is obtained according to the original volume of the insoluble matter content and the expanded volume of the insoluble residue.

2. The method for determining the residue accumulation coefficient of a salt cavern gas storage according to claim 1, characterized in that: The method of determining the insoluble matter content of formations at different depths based on the gamma logging interpretation results includes: According to the gamma logging interpretation results and the insoluble content calculation formula, the initial insoluble content at different depths is determined; The initial insoluble matter content is corrected using a correction formula to obtain the insoluble matter content of formations at different depths.

3. The method for determining the residue accumulation coefficient of a salt cavern gas storage according to claim 2, characterized in that: The insoluble matter content calculation formula is: Where C i 1 H i The insoluble matter content at the depth of the formation, GR is H i Gamma value at formation depth, GR min is the natural gamma value of the sandstone layer, GR max is the natural gamma value of the mudstone layer.

4. The method for determining the residue accumulation coefficient of a salt cavern gas storage according to claim 2, characterized in that: The correction formula is: In the above formula, GCUR is the empirical coefficient related to the formation, C i H i Insoluble matter content C at formation depth i 1 .

5. The method for determining the residue accumulation coefficient of a salt cavern gas storage according to claim 4, characterized in that: The method also includes: If the age of the stratum is the Tertiary stratum or above, GCUR = 3.7; If the age of the stratum is older than the Tertiary System, GCUR = 2.

0.

6. The method for determining the residue accumulation coefficient of a salt cavern gas storage according to claim 2, characterized in that: The original volume of the insoluble content is: S1=|∑CiΔvi|; In the above formula, S1 is the original volume of insoluble matter, C i H i Insoluble matter content C at formation depth i 1 , Δvi is H i Volume difference at formation depth.

7. The method for determining the residue accumulation coefficient of a salt cavern gas storage according to claim 6, characterized in that: The expanded volume of the insoluble residue is: S2=|∑CiΔvi|; In the above formula, S2 is the expansion volume of the insoluble residue.

8. The method for determining the residue accumulation coefficient of a salt cavern gas storage according to claim 7, characterized in that: The insoluble residue accumulation coefficient is: δ = S1 / S2; In the above formula, δ is the insoluble residue accumulation coefficient.

9. A device for determining the residue accumulation coefficient of a salt cavern gas storage, characterized in that: The device includes: a memory and a processor; the memory is used to store a program for determining the residual accumulation coefficient of the salt cavern gas storage, and the processor is used to read and execute the program for determining the residual accumulation coefficient of the salt cavern gas storage, and perform the method according to any one of claims 1 to 8.

10. A computer-readable storage medium having a data processing program stored thereon, wherein a processor executes the method for determining the residue accumulation coefficient of a salt cavern gas storage according to any one of claims 1 to 8.

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