Method for evaluating filling effect of salt cavern solid waste slurry

Abstract

This invention discloses a method for evaluating the filling effect of salt cavern solid waste slurry. The method first obtains the effective cavity volume, initial brine volume, and characteristic component content of the original solid phase material within the salt cavern to be evaluated. Then, based on the injection parameters of the injected solid waste slurry during the filling process, the method calculates the injected dry-base solid mass and injected liquid phase volume. Simultaneously, based on the backflow parameters, the method calculates the backflow solid mass, backflow liquid phase volume, and backflow loss mass originating from the injected slurry solids. Further, the method calculates the effective retained solid mass, solid retention rate, effective deposition volume, effective deposition pore volume, and free residual brine volume within the salt cavern, ultimately determining the effective cavity occupancy rate and free brine residue rate of the salt cavern solid waste slurry filling. This invention comprehensively considers the impact of backflow solid loss, deposition compaction in a brine environment, and free brine residue on the actual filling effect, providing a quantitative basis for evaluating the filling effect of salt cavern solid waste slurry and designing supplementary filling.

Description

Technical Field

[0001] This invention relates to the field of salt cavern underground space remediation technology, specifically to an evaluation method for the filling effect of salt cavern solid waste slurry. Background Technology

[0002] The remediation of underground spaces in salt caverns and the technology for filling solid waste slurry have gradually become important directions for the large-scale disposal of industrial solid waste and the stable control of underground spaces. Salt caverns, as deep underground cavities formed after water-soluble salt mining, are characterized by their large depth, large spatial scale, and good sealing properties, providing important sites for the filling and disposal of solid waste slurry. However, salt caverns often retain high-concentration brine for extended periods, leading to problems such as slurry dilution, solid loss with backflow liquid, unclear compaction of the sediment, and retention of free brine during the filling process. These issues make it difficult to accurately evaluate the actual filling effect.

[0003] Current methods for evaluating the effectiveness of salt cavern filling rely heavily on the volume of injected slurry, the mass of injected solids, or the amount of brine returned, making it difficult to accurately reflect the effective retention, sedimentation volume, and actual cavity occupancy of solid waste slurry within the salt cavern. Specifically, existing evaluation methods have the following shortcomings: First, they fail to distinguish between the source of injected solid waste slurry and the original solids in the salt cavern during return, leading to inaccurate calculations of return loss mass. Second, they do not consider the settling and compaction characteristics of the solid waste slurry sediment in a brine environment, resulting in deviations in the calculation of effective sedimentation volume. Third, they fail to distinguish between pore brine and free residual brine in the sediment, leading to inaccurate evaluations of effective cavity occupancy. Fourth, they lack quantitative comparisons with target values, making it difficult to determine whether the filling effect meets design requirements and the main controlling factors when it is insufficient. Therefore, it is necessary to establish an evaluation method for the effectiveness of salt cavern solid waste slurry filling that comprehensively considers factors such as return solid loss, sediment compaction, and free brine residue. Summary of the Invention

[0004] The purpose of this invention is to provide a method for evaluating the filling effect of salt cavern solid waste slurry, so as to solve the above-mentioned technical problems.

[0005] The technical solution adopted by this invention to solve its technical problem is: a method for evaluating the filling effect of salt cavern solid waste slurry, comprising the following steps: S1. Obtain the basic parameters for evaluating the salt cavern, including the effective cavity volume of the salt cavern before the start of the solid waste slurry filling operation, the initial brine volume, and the content of characteristic components in the original solid phase material in the salt cavern. S2. Obtain injection parameters during the solid waste slurry backfilling process. The injection parameters include the volume of the injected slurry, the density of the injected slurry, the mass solid content of the injected slurry, the density of the solid particles in the injected slurry, and the content of the solid characteristic components in the injected solid waste slurry. Calculate the mass of the injected dry-based solids and the volume of the injected liquid phase based on the injection parameters. Obtain return parameters during the solid waste slurry backfilling process. The return parameters include the volume of the return liquid, the density of the return liquid, the mass solid content of the return liquid, the density of the return solid particles, and the content of the solid characteristic components in the return liquid. Calculate the mass of the return solids and the volume of the return liquid phase based on the return parameters. S3. Based on the content of characteristic components of the returned solids, the content of characteristic components of the injected solid waste slurry, and the content of characteristic components in the original solid phase material in the salt cavern, determine the mass ratio of solids originating from the injected solid waste slurry in the returned solids, and calculate the mass of returned solids lost from the injected solid waste slurry based on the mass ratio of solids in the injected solid waste slurry and the mass of the returned solids. S4. Calculate the effective solid mass retained in the salt cavern based on the injected dry base solid mass and the returned loss mass of the injected solid waste slurry solid, and calculate the actual solid retention rate based on the effective solid mass retained and the injected dry base solid mass. S5. Calculate the effective sedimentation volume in the salt cavern based on the effective retained solid mass and the equivalent settling density of the solid waste slurry sediment in the brine environment. S6. Calculate the effective sediment porosity based on the equivalent sedimentation compaction dry density and the solid particle density of the injected slurry, and calculate the effective sediment pore volume based on the effective sediment volume and the effective sediment porosity. S7. Calculate the residual liquid phase volume in the salt cavern based on the initial brine volume, the injected liquid phase volume, and the drained liquid phase volume, and calculate the free residual brine volume in the salt cavern based on the residual liquid phase volume in the salt cavern and the effective sediment pore volume. S8. Based on the effective sedimentation volume, free residual brine volume, and effective cavity volume, calculate the actual effective cavity occupancy rate and actual free brine residual rate of the salt cavern solid waste slurry filling. S9. The filling effect of salt cavern solid waste slurry is evaluated by comparing the actual effective cavity occupancy rate with the target effective cavity occupancy rate, the actual free brine residue rate with the target brine residue rate, and the actual solid retention rate with the target solid retention rate.

[0006] More specifically, in step S2, the mass of the injected dry-based solids The formula for determining it is: ; In the formula, For the first Density of injected slurry at each injection stage For the first Volume of injected slurry in each injection stage For the first Solid content of the injected grout at each injection stage. Number of injection stages; The volume of injected liquid phase The formula for determining it is: ; In the formula, The density of solid particles in the injected slurry.

[0007] More specifically, in step S2, the mass of the returned solids The formula for determining it is: ; In the formula, For the first Density of the backflow fluid at each backflow stage For the first The volume of backflow liquid in each backflow stage. For the first Solid content of the backflow liquid in each backflow stage This refers to the number of items in the return-to-work phase; The volume of the backflow liquid phase The formula for determining it is: ; In the formula, This represents the density of the returned solid particles.

[0008] More specifically, the content of the characteristic components of the backflow solids is used to distinguish between the solid phase material of the injected slurry and the original solid phase material of the salt cavern. The content of the characteristic components of the backflow solids includes one or more of the following: silicon dioxide, aluminum oxide, iron oxide, calcium oxide, magnesium oxide, loss on ignition, insoluble matter content, chloride content, sulfate content, and characteristic particle size content. In step S3, when the mass proportion of solids derived from injected solid waste slurry in the returned solids is determined using the content of one of the characteristic components of the returned solids, the mass proportion of solids derived from injected solid waste slurry is... The formula for determining it is: ; In the formula, For the first Content of characteristic components of the backflow solids in each backflow stage To determine the content of characteristic solid components in the injected solid waste slurry. The content of characteristic components in the original solid phase material within the salt cavern; When determining the mass proportion of solids derived from injected solid waste slurry in the returned solids using the content of various characteristic components of the returned solids, the formula for determining the mass proportion of solids derived from injected solid waste slurry is as follows: ; In the formula, The number of characteristic components, For the first The weights of the characteristic components, For the first The first stage of the return solids Content of characteristic components For the first injection into the slurry Content of characteristic components The first of the original solid phase substances in the salt cavern The content of a certain characteristic component, and satisfying the following: ; when At that time, take ;when When, take the current calculated value; when At that time, take ; The mass of solids lost during the return discharge of the injected solid waste slurry The formula for determining it is: .

[0009] More specifically, in step S4, the effective solid mass retained in the salt cavern is... The formula for determining it is: ; The actual solids retention rate The formula for determining it is: .

[0010] More specifically, in step S5, the effective deposition volume The formula for determining it is: ; In the formula, It is the equivalent settling compaction dry density of solid waste slurry sediment in a brine environment.

[0011] More specifically, in step S6, the effective deposit porosity The formula for determining it is: ; The effective sediment pore volume The formula for determining it is: .

[0012] More specifically, in step S7, the volume of the residual liquid phase in the salt cavern... The formula for determining it is: ; When there is a change in liquid phase volume caused by a chemical phase change in solid waste slurry, the correction amount for the liquid phase volume caused by the chemical phase change in solid waste slurry is obtained, and the residual liquid phase volume in the salt cavern is obtained. The formula for determining it is: ; In the formula, The initial brine volume before filling the salt cavern; This is the liquid phase volume correction amount; when the liquid phase volume increases... When the value is positive, the liquid phase volume decreases. Take the negative value; The volume of the free residual brine The formula for determining it is: ; when At that time, take: ; In the formula, The effective cavity volume.

[0013] More specifically, in step S8, the actual effective cavity occupancy rate The formula for determining it is: ; The actual free brine residue rate The formula for determining it is: ; When the actual effective cavity occupancy rate Actual free brine residue rate Actual solid retention rate At that time, it was determined that the filling effect of the salt cavern solid waste slurry met the requirements; In the formula, To achieve the target effective cavity occupancy rate, To achieve the target free brine residue rate, The target solids retention rate.

[0014] More specifically, if the salt cavern filling effect does not meet the requirements, the required dry base solids are added. The volume of the additional filling slurry is calculated based on the required mass of dry base solids. The formula for determining it is: ; In the formula, To achieve the target effective cavity occupancy rate, To supplement the expected equivalent settlement compaction dry density of the filling grout in a brine environment, To supplement the expected solids retention rate during the filling stage; The volume of the supplementary filling grout The formula for determining it is: ; In the formula, To supplement the density of the filling grout, To supplement the solids content of the filling grout.

[0015] The technical effects of this invention are: (1) This invention does not use the volume of injected slurry or the mass of injected solids as the basis for evaluating the filling effect of salt caverns. Instead, it distinguishes the source of injected slurry solids and original solids in salt caverns by the content of characteristic components. It deducts the injected slurry solids lost during the return process and calculates the effective mass of solids retained in salt caverns. This can avoid overestimation of the filling effect caused by evaluating only the injection volume. (2) The present invention incorporates the equivalent settling compaction dry density of solid waste slurry sediment in brine environment into the calculation of effective sediment volume, and further calculates the porosity and pore volume of effective sediment, which can reflect the influence of solid waste slurry settling, compaction and pore development on the actual cavity occupancy under high salinity brine environment. (3) The present invention further distinguishes the residual liquid volume into effective sediment pore liquid and free residual brine, which can identify the free brine space in the salt cave that is not effectively occupied by solid waste slurry, thereby more accurately evaluating the actual degree of occupation of the effective cavity space of the salt cave by solid waste slurry. (4) The present invention can quantitatively determine whether the filling effect of salt cavern meets the design requirements by comparing the actual effective cavity occupancy rate, actual free brine residual rate and actual solid retention rate with their respective target values, and can further calculate the dry base solid mass and the volume of supplementary filling slurry required for supplementary filling, providing a quantitative basis for the evaluation of salt cavern filling effect, supplementary filling design and long-term stability analysis. Attached Figure Description

[0016] Figure 1 This is a flowchart of the evaluation method for the filling effect of salt cavern solid waste slurry according to the present invention. Detailed Implementation

[0017] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] This invention provides a method for evaluating the filling effect of solid waste slurry in salt caverns. It is applicable to evaluating the filling effect of solid waste slurry in abandoned salt caverns, decommissioned salt caverns, old brine pits, or salt caverns awaiting treatment. Before filling, a certain volume of brine exists within the salt cavern. During the filling process, solid waste slurry is injected into the salt cavern through an injection well. The solid waste slurry includes salt chemical solid waste slurry, coal-based solid waste slurry, mining solid waste slurry, composite solid waste slurry, or solid waste slurry containing cementing components. The brine and some return liquid containing entrained solid particles are discharged through a return well or return channel. Figure 1 As shown, it includes: Step 1: Determine the basic parameters of the salt cavern to be evaluated, and obtain the effective cavity volume, initial brine volume, and characteristic component content of the original solid phase material in the salt cavern before the start of the solid waste slurry filling operation.

[0019] The effective cavity volume is denoted as The volume of salt cavern space that can be entered and occupied by solid waste slurry before the filling operation begins can be determined through one or more of the following: sonar cavity data, 3D geophysical interpretation data, cavity construction production data, salt production back-calculation data, wellbore liquid level data, salt cavern connectivity data, or salt cavern creep volume correction data. When there are existing sediment, non-connected spaces, gas phase spaces, or unfillable blind areas within the salt cavern, the total cavity volume of the salt cavern should be corrected. After deducting the original unfillable sediment volume, non-connected space volume, non-displaceable gas phase volume, or unfillable blind area volume, the effective cavity volume is obtained. .

[0020] The initial brine volume before filling the salt cavern is denoted as . When the salt cavern is filled with brine, the initial brine volume can be determined according to the effective cavity volume; when the salt cavern is partially filled with liquid, the initial brine volume is determined according to the liquid level, cavity shape and well volume.

[0021] The content of characteristic components in the original solid phase material within the salt cavern is denoted as: , refers to the background mass content of characteristic components in the original sediment, salt crystals, well wall spalling material or pipeline abrasion products in the salt cavern. The content of characteristic components in the original solid phase material in the salt cavern can be determined by sediment sampling analysis, well wall core sampling analysis, pipeline abrasion product sampling analysis or historical data of similar salt caverns during the salt cavern construction process.

[0022] Step 2: Obtain the injection and return parameters during the solid waste slurry filling process, and calculate the injected dry solid mass, injected liquid volume, return solid mass, and return liquid volume. The injection parameters include the injected slurry volume, injected slurry density, injected slurry mass solids content, injected slurry solid particle density, and injected solid waste slurry solid characteristic component content during the injection stage. The return parameters include the return liquid volume, return liquid density, return liquid mass solids content, return solid particle density, and return solid characteristic component content during the return stage.

[0023] During the solid waste slurry backfilling process, the injection process is divided into n injection stages. The injected slurry volume, injected slurry density, and injected slurry mass solids content, as well as the injected dry base solids mass, are recorded for each injection stage. Calculate according to the following formula: ; In the formula, For the first Density of injected slurry at each injection stage For the first Volume of injected slurry in each injection stage For the first Solid content of the injected grout at each injection stage. Number of injection stages; Further calculation of the injected liquid phase volume : ; In the formula, The density of solid particles in the injected slurry.

[0024] During the solid waste slurry backfilling process, the backfilling process is divided into m backfilling stages, and the backfilling liquid volume, backfilling liquid density, backfilling liquid mass solid content and backfilling solid particle density are recorded for each backfilling stage.

[0025] The mass of the returned solids Calculate according to the following formula: ; In the formula, For the first Density of the backflow fluid at each backflow stage For the first The volume of backflow liquid in each backflow stage. For the first Solid content of the backflow liquid in each backflow stage This refers to the number of items in the return-to-work phase; Further calculation of the return liquid phase volume : ; In the formula, This represents the density of the returned solid particles.

[0026] Step 3: Determine the mass proportion of solids originating from the injected solid waste slurry in the returned solids, and calculate the mass of returned solids lost from the injected solid waste slurry.

[0027] During the solid waste slurry backfilling process, since the returned solids may include solid particles from the injected solid waste slurry and the original solid phase material in the salt cavern, the total mass of returned solids cannot be regarded as the loss of the injected solid waste slurry solids. In this embodiment, the source of returned solids is identified by selecting characteristic components that can distinguish between the injected solid waste slurry solids and the original solids in the salt cavern. The characteristic components in the returned solids include one or more of the following: silica, alumina, iron oxide, calcium oxide, magnesium oxide, loss on ignition, insoluble matter content, chloride content, sulfate content, or characteristic particle size content.

[0028] When using a single characteristic component, the first The mass proportion of solids originating from injected solid waste slurry in the return solids at each stage of the return process Calculate according to the following formula: ; In the formula, For the first Mass content of characteristic components in the return solids of each return stage; This refers to the mass content of characteristic components in the injected solid waste slurry. The background mass content of characteristic components in the original sediment, salt crystals, well wall spalling material or pipeline abrasion products in the salt cavern; When multiple characteristic components are used, the mass ratio is calculated according to the following formula: ; In the formula, The number of characteristic components, For the first The weights of the characteristic components, For the first The first stage of the return solids Content of characteristic components For the first injection into the slurry Content of characteristic components The first of the original solid phase substances in the salt cavern The content of a certain characteristic component, and satisfying the following: ; Among them, the characteristic components should satisfy and When the difference between them is greater than the preset recognition threshold, At that time, take ;when When, take the current calculated value; when At that time, take ; Calculate the mass loss of injected solid waste slurry solids in the returned solids based on the mass proportion of solids originating from the injected solid waste slurry. : .

[0029] Step 4: Calculate the effective solid mass and actual solid retention rate in the salt cavern.

[0030] Calculate the effective solids retained in the salt cavern based on the injected dry base solids mass and the backflow loss mass. : ; Further calculation of the actual solid retention rate : .

[0031] This step is used to deduct the solids of the injected solid waste slurry lost during the return process, so as to avoid overestimating the cavity occupancy rate by evaluating the filling effect solely based on the total mass of the injected solid waste slurry.

[0032] Step 5: Calculate the effective deposition volume within the salt cavern.

[0033] Before calculating the effective sediment volume, it is necessary to obtain the equivalent settling density (dry density) of the solid waste slurry sediment in a brine environment. The equivalent settling compaction dry density can be determined through one or more of the following methods: brine settling test, static compaction test, consolidation compaction test, on-site sediment sampling test, or calibration of historical data from similar salt cavern solid waste slurry filling. The brine salinity, test temperature, static compaction time, or compaction pressure used in the brine settling test, static compaction test, or consolidation compaction test should be compatible with the brine salinity, salt cavern temperature, filling static time, and sediment burial depth pressure within the salt cavern to be evaluated. The effective sediment volume within the salt cavern is calculated using the following formula: .

[0034] Step 6: Calculate the effective sediment porosity and effective sediment pore volume.

[0035] The effective porosity of the sediment is calculated based on the solid phase particle density and equivalent settling compaction dry density of the solid waste slurry. : ; Further calculation of effective sediment pore volume : .

[0036] Step 7: Calculate the volume of the residual liquid phase and the volume of the free residual brine in the salt cavern.

[0037] Calculate the residual liquid volume in the salt cavern based on the initial brine volume, the injected liquid phase volume, and the flowback liquid phase volume. : ; In the formula, The initial brine volume before filling the salt cavern; When there are changes in liquid phase volume due to water consumption during solid waste slurry hydration, salt dissolution, salt crystallization, or chemical reactions, the liquid phase volume correction caused by the chemical phase change of the solid waste slurry is obtained. The liquid phase volume correction is determined through laboratory phase change volume simulation experiments and in conjunction with on-site determination of the mass of the solid phase involved in the reaction. The residual liquid phase volume in the salt cavern is calculated according to the following formula: ; In the formula, This is the liquid phase volume correction amount; when the liquid phase volume increases... When the value is positive, the liquid phase volume decreases. Take the negative value; Then calculate the volume of the free residual brine. : ; In the formula, max represents taking the maximum value among the values ​​within the parentheses; when At that time, take: ; In the formula, The effective cavity volume.

[0038] This step is used to distinguish between the liquid in the pores of the effective sediment and the free residual brine outside the sediment. The free residual brine directly occupies the effective cavity space of the salt cavern and can reflect the scale of space that the solid waste slurry has not effectively occupied.

[0039] Step 8: Calculate the actual effective cavity occupancy rate and actual free brine residue rate of the salt cavern solid waste slurry filling.

[0040] Actual effective cavity occupancy rate of salt cavern solid waste slurry filling Calculate according to the following formula: ; Actual free brine residue rate Calculate according to the following formula: .

[0041] Step 9: Evaluate the filling effect of salt cavern solid waste slurry.

[0042] The filling effect of the salt cavern is evaluated by comparing the actual effective cavity occupancy, actual free brine residue rate, and actual solid retention rate with their respective target values. The filling effect is deemed to meet the design requirements when the actual effective cavity occupancy is not less than the target effective cavity occupancy, the actual free brine residue rate is not greater than the target free brine residue rate, and the actual solid retention rate is not less than the target solid retention rate. When the actual effective cavity occupancy rate is less than the target effective cavity occupancy rate, and the actual solid retention rate is less than the target solid retention rate, but the actual free brine residue rate is not greater than the target free brine residue rate, it is determined that the amount of solids lost from the salt cavern is too large and does not meet the design requirements.

[0043] When the actual effective cavity occupancy rate is less than the target effective cavity occupancy rate, and the actual free brine residue rate is greater than the target free brine residue rate, but the actual solid retention rate is not less than the target solid retention rate, it is determined that there is too much free brine residue in the salt cavern and the design requirements are not met.

[0044] When the actual effective cavity occupancy rate is less than the target effective cavity occupancy rate, and the actual solid retention rate is not less than the target solid retention rate, but the actual free brine residue rate is not greater than the target free brine residue rate, it is determined that the solid waste slurry sediment in the salt cave is not compacted enough or the amount of injected solids is insufficient, and the design requirements are not met.

[0045] When the salt cavern filling effect does not meet the design requirements, calculate the required dry base solid mass for filling. : ; In the formula, To achieve the target effective cavity occupancy rate, To supplement the expected equivalent settlement compaction dry density of the filling grout in a brine environment, To supplement the expected solids retention rate during the filling stage; when At that time, take .

[0046] Further calculation of the volume of supplementary filling grout : ; In the formula, To supplement the density of the filling grout; To supplement the solids content of the filling grout.

[0047] Through the above steps, the effective cavity occupancy rate, solid retention rate, free brine residue rate, and replenishment filling requirements after filling the salt cavern with solid waste slurry can be determined, providing a basis for evaluating the filling effect of the salt cavern and subsequent engineering control.

[0048] Example 1: This embodiment uses a waste salt cavern solid waste slurry filling project as an example to illustrate the evaluation method of the filling effect of the salt cavern solid waste slurry of the present invention.

[0049] (1) Basic parameters of salt cave Based on sonar cavity measurement data, wellbore fluid level data, and salt cavern connectivity data before filling, the effective cavity volume of the salt cavern was determined. Initial brine volume in the salt cavern before filling The analysis of sediment samples taken during the salt cavern construction process determined that the original solid phase material inside the salt cavern included sediment, salt crystals, and well wall debris. The salt cavern was in a partially liquid-filled state, with the remaining space being the wellbore and the local gas phase space above the salt cavern.

[0050] (2) Parameters of injected grout The filling process of the salt cavern solid waste slurry was divided into three injection stages, and the injection parameters for each stage are shown in Table 1. Table 1 Injection parameters at each stage

[0051] The equivalent particle density of the injected slurry solid particles is taken as: , The formula for determining the mass of injected dry-based solids is: ; Substitute the injection parameters at each stage to determine the quality of the injected dry matrix: Phase 1: ; Phase Two: ; Phase Three: ; Total mass of injected dry-based solids: ; The formula for determining the volume of the injected liquid phase is: ; Substitute the injection parameters for each stage to determine the injection liquid volume: .

[0052] (3) Flowback fluid parameters The salt cavern filling process was divided into three flowback stages, and the parameters of the flowback fluid in each stage are shown in Table 2. Table 2 Parameters of Flowback Fluid at Each Stage

[0053] The equivalent particle density of the returned solids is taken as: ; The formula for determining the total mass of returned solids is: ; Substitute the return parameters for each stage to determine the return solid mass: Phase 1: ; Phase Two: ; Phase Three: ; Total mass of returned solids ; The formula for determining the volume of the flowback liquid phase is: ; Substitute the flowback parameters for each stage to determine the flowback liquid phase volume. .

[0054] (4) Identification of sources of returned solids Since the original solids in the salt cavern contain extremely low levels of silica, and silica is a hallmark component of the solid phase of the injected solid waste slurry, silica content was selected as a characteristic component to distinguish the injected slurry solids from the original solids in the salt cavern.

[0055] The mass content of silica in the injected solid waste slurry was determined by laboratory testing to be [missing information]. The background silica content in the original sediment, salt crystals, and flaking material from the well wall within the salt cavern was: The mass content of silica in the return solids at each return stage is shown in Table 3: Table 3. Mass content of silica in the return solids at each return stage

[0056] The formula for determining the mass proportion of solids derived from the injected slurry in the returned solids is: ; The mass proportion of solids derived from the injected slurry in the flowback solids at each stage is as follows: Phase 1: ; Phase Two: ; Phase Three: .

[0057] The formula for determining the mass of solids lost during the return discharge of injected solid waste slurry is as follows: ; Substitute the mass proportion of solids originating from the injected slurry into the returned solids at each stage, and the mass of returned solids lost from the injected solid waste slurry. .

[0058] (5) Effective retained solid mass and solid retention rate The formula for determining the effective mass of solids retained in a salt cavern is: Substituting the injected dry-based solid mass and the flowback loss mass, we can obtain: 14102.12 327.69 = 13774.43t; The formula for determining the solid retention rate of the injected slurry is: Substituting the relevant data, we can obtain: During the filling process of the salt cavern solid waste slurry, the effective retention rate of the injected solids was 97.7%.

[0059] (6) Effective sediment volume In this embodiment, the equivalent settling density dry density of the solid waste slurry sediment was measured in the target brine environment through a brine settling compaction test. The formula for determining the effective deposition volume within a salt cavern is: ; Substituting the effective retained solid mass and the measured equivalent settlement compaction dry density data, we can obtain: .

[0060] (7) Effective pore volume of sediment The formula for determining the effective porosity of a sedimentary body is: ; Substituting the data of equivalent settling compaction dry density of the solid waste slurry sediment and the particle density of the injected slurry solid phase into the target brine environment, we can obtain: .

[0061] The formula for determining the effective pore volume of a sedimentary body is: ; Substituting the data for effective sediment porosity and effective sediment volume within the salt cavern, we can obtain: .

[0062] (8) Volume of free residual brine The formula for determining the volume of residual liquid phase in the salt cavern is: ; Substituting the initial brine volume, injected liquid phase volume, and drained liquid phase volume before filling the salt cavern, we can obtain: ; The formula for determining free residual brine is: ; Substituting the calculated residual liquid volume and effective sediment pore volume into the data, we can obtain: ; The difference between the effective cavity volume and the effective deposition volume is: Due to the free residual brine Therefore, there is no need to trigger boundary correction conditions for the free residual brine. Take 2368.08m 3 .

[0063] (9) Actual effective cavity occupancy rate and actual free brine residue rate The formula for determining the actual effective cavity occupancy ratio of salt cavern solid waste slurry filling is as follows: ; Substituting the calculated effective deposition volume and effective cavity volume of the salt cavern, we can obtain: That is, the effective cavity occupancy rate is approximately 78.5%.

[0064] The formula for determining the actual free brine residue rate is: ; Substituting the calculated data of free residual brine and effective cavity volume of salt cavern, we can obtain: That is, the free brine residue rate is about 21%.

[0065] (10) Evaluation of filling effect Set target effective cavity ratio Set target free brine residue rate Set target solids retention rate Based on the above results, the actual effective cavity occupancy rate 0.785 is greater than the target effective cavity ratio. Actual free brine residue rate Less than the target free brine residual rate Actual effective solids retention rate Greater than the target effective solid retention rate Therefore, it was determined that the filling effect of the solid waste slurry in the salt cavern met the design requirements.

[0066] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for evaluating the filling effect of salt cavern solid waste slurry, characterized in that, Includes the following steps: S1: Obtain the basic parameters for evaluating salt caverns; S2: Obtain the injection parameters during the solid waste slurry backfilling process, and calculate the injected dry solid mass and injected liquid volume based on the injection parameters; Obtain the backflow parameters during the solid waste slurry backfilling process, and calculate the backflow solid mass and backflow liquid volume based on the backflow parameters; S3: Based on the basic parameters, injection parameters, and return parameters, determine the mass ratio of solids originating from the injected solid waste slurry in the returned solids, and calculate the return loss mass of the injected solid waste slurry based on the mass ratio of solids in the injected solid waste slurry and the mass of the returned solids. S4: Calculate the effective solid mass retained in the salt cavern based on the injection parameters and the return loss mass of the injected solid waste slurry, and calculate the actual solid retention rate based on the effective solid mass retained and the injected dry basis solid mass. S5: Calculate the effective sedimentation volume in the salt cavern based on the effective retained solid mass and the equivalent settling density of the solid waste slurry sediment in the brine environment; S6: Calculate the effective sediment porosity based on the equivalent sedimentation compaction dry density and injection parameters, and calculate the effective sediment pore volume based on the effective sediment volume and effective sediment porosity. S7: Calculate the residual liquid phase volume in the salt cavern based on the basic parameters, the injected liquid phase volume, and the flowback liquid phase volume, and calculate the free residual brine volume in the salt cavern based on the residual liquid phase volume in the salt cavern and the effective sediment pore volume. S8: Based on the effective sedimentation volume, free residual brine volume and basic parameters, calculate the actual effective cavity occupancy rate and actual free brine residual rate of the salt cavern solid waste slurry filling. S9: The filling effect of salt cavern solid waste slurry is evaluated by comparing the actual effective cavity occupancy rate with the target effective cavity occupancy rate, the actual free brine residue rate with the target brine residue rate, and the actual solid retention rate with the target solid retention rate.

2. The method for evaluating the filling effect of salt cavern solid waste slurry according to claim 1, characterized in that, The injection parameters include the volume of the injected slurry, the density of the injected slurry, the mass solids content of the injected slurry, the density of solid particles in the injected slurry, and the content of solid characteristic components in the injected solid waste slurry during the injection stage. In step S2, the mass of the injected dry-based solids The formula for determining it is: ； In the formula, For the first Density of injected slurry at each injection stage For the first Volume of injected slurry in each injection stage For the first Solid content of the injected grout at each injection stage. Number of injection stages; The volume of injected liquid phase The formula for determining it is: ； In the formula, The density of solid particles in the injected slurry.

3. The method for evaluating the filling effect of salt cavern solid waste slurry according to claim 2, characterized in that, The backflow parameters include the backflow liquid volume, backflow liquid density, backflow liquid mass solids content, backflow solid particle density, and backflow solid characteristic component content during the backflow stage; In step S2, the mass of the returned solids The formula for determining it is: ； In the formula, For the first Density of the backflow fluid at each backflow stage For the first The volume of backflow liquid in each backflow stage. For the first Solid content of the backflow liquid in each backflow stage This refers to the number of items in the return-to-work phase; The volume of the backflow liquid phase The formula for determining it is: ； In the formula, This represents the density of the returned solid particles.

4. The method for evaluating the filling effect of salt cavern solid waste slurry according to claim 3, characterized in that, The basic parameters include the effective cavity volume of the salt cavern before the start of the solid waste slurry filling operation, the initial brine volume, and the content of characteristic components in the original solid phase material in the salt cavern; the content of characteristic components of the returned solids is used to distinguish between the solid phase material of the injected slurry and the original solid phase material of the salt cavern, and the content of characteristic components of the returned solids includes one or more of the following: silica, alumina, iron oxide, calcium oxide, magnesium oxide, loss on ignition, insoluble matter content, chloride content, sulfate content, and characteristic particle size content; In step S3, when the mass proportion of solids derived from injected solid waste slurry in the returned solids is determined using the content of one of the characteristic components of the returned solids, the mass proportion of solids derived from injected solid waste slurry is... The formula for determining it is: ； In the formula, For the first Content of characteristic components of the backflow solids in each backflow stage To determine the content of characteristic solid components in the injected solid waste slurry. The content of characteristic components in the original solid phase material within the salt cavern; When determining the mass proportion of solids derived from injected solid waste slurry in the returned solids using the content of various characteristic components of the returned solids, the formula for determining the mass proportion of solids derived from injected solid waste slurry is as follows: ； In the formula, The number of characteristic components, For the first The weights of the characteristic components, For the first The first stage of the return solids in the return stage Content of characteristic components For the first injection into the slurry Content of characteristic components The first of the original solid phase substances in the salt cavern The content of a certain characteristic component, and satisfying the following: ； when At that time, take ;when When, take the current calculated value; when At that time, take ; The mass of solids lost during the return discharge of the injected solid waste slurry The formula for determining it is: 。 5. The method for evaluating the filling effect of salt cavern solid waste slurry according to claim 4, characterized in that, In step S4, the effective solid mass retained in the salt cavern is... The formula for determining it is: ； The actual solids retention rate The formula for determining it is: 。 6. The method for evaluating the filling effect of salt cavern solid waste slurry according to claim 5, characterized in that, In step S5, the effective deposition volume The formula for determining it is: ； In the formula, It is the equivalent settling compaction dry density of solid waste slurry sediment in a brine environment.

7. The method for evaluating the filling effect of salt cavern solid waste slurry according to claim 6, characterized in that, In step S6, the effective porosity of the deposited body The formula for determining it is: ； The effective sediment pore volume The formula for determining it is: 。 8. The method for evaluating the filling effect of salt cavern solid waste slurry according to claim 7, characterized in that, In step S7, the volume of the residual liquid phase in the salt cavern The formula for determining it is: ； When there is a change in liquid phase volume caused by a chemical phase change in solid waste slurry, the correction amount for the liquid phase volume caused by the chemical phase change in solid waste slurry is obtained, and the residual liquid phase volume in the salt cavern is obtained. The formula for determining it is: ； In the formula, The initial brine volume before filling the salt cavern; This is the liquid phase volume correction amount; when the liquid phase volume increases... When the value is positive, the liquid phase volume decreases. Take the negative value; The volume of the free residual brine The formula for determining it is: ； when At that time, take: ; In the formula, The effective cavity volume.

9. The method for evaluating the filling effect of salt cavern solid waste slurry according to claim 8, characterized in that, In step S8, the actual effective cavity occupancy rate The formula for determining it is: ； The actual free brine residue rate The formula for determining it is: ； When the actual effective cavity occupancy rate Actual free brine residue rate Actual solid retention rate At that time, it was determined that the filling effect of the salt cavern solid waste slurry met the requirements; In the formula, To achieve the target effective cavity occupancy rate, To achieve the target free brine residue rate, The target solids retention rate.

10. The method for evaluating the filling effect of salt cavern solid waste slurry according to claim 9, characterized in that, If the salt cavern filling effect does not meet the requirements, the required dry base solids are added. The volume of the additional filling slurry is calculated based on the required mass of dry base solids. The formula for determining it is: ； In the formula, To achieve the target effective cavity occupancy rate, To supplement the expected equivalent settlement compaction dry density of the filling grout in a brine environment, To supplement the expected solids retention rate during the filling stage; The volume of the supplementary filling grout The formula for determining it is: ； In the formula, To supplement the density of the filling grout, To supplement the solids content of the filling grout.

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