Cavity creation dynamic tracking analysis method

Abstract

The present application belongs to the field of gas storage, and particularly relates to a cavity forming dynamic tracking analysis method, aiming at solving the problem of lacking systematic analysis method when processing complex cavity forming data. The present application comprises: obtaining cavity forming data, calculating salt cavity effective volume based on the cavity forming data; obtaining the underground soluble salt volume and static volume formula based on the salt cavity effective volume; calculating the current cavity forming progress and cavity forming engineering progress based on the underground soluble salt volume; calculating the wellhead water injection pressure and oil cushion pressure based on the blocking solvent interface depth and along-the-way water head loss; calculating the wellhead nitrogen pressure based on the connecting point liquid column pressure balance principle; calculating the gas-water interface depth based on the volume formula; and calculating the pressure at the gas-water interface at the well bottom based on the gas-water interface depth. The present application can accurately reflect the actual state of cavity forming, optimize the salt cavity development process, and improve the resource utilization efficiency.

Description

Technical Field

[0001] This invention belongs to the field of gas storage facilities, and specifically relates to a method for dynamic tracking and analysis of cavity construction. Background Technology

[0002] In the development and management of salt cavern gas storage facilities, dynamic monitoring of cavity construction is a crucial step. Current technologies primarily involve parameters such as discharge rate, water injection pressure, oil pad pressure, and brine concentration. These parameters can be used to estimate cavity volume and predict potential accidents during construction. However, existing technologies often lack systematic analytical methods when processing complex cavity construction data, leading to deviations between the cavity shape and the initial design. These deviations can cause technical problems such as insufficient cavity volume in single wells and actual storage capacity being less than the designed capacity, thus affecting the operational efficiency and safety of the gas storage facility. Therefore, a more accurate and comprehensive dynamic tracking and analysis method for cavity construction is urgently needed to improve the management level and safety performance of salt cavern gas storage facilities. Summary of the Invention

[0003] To address the aforementioned problems in existing technologies, namely the lack of systematic analysis methods when processing complex cavity creation data, leading to deviations between the cavity shape and the initial design and subsequent issues, this invention provides a dynamic tracking and analysis method for cavity creation. The method tracks parameters including: cavity creation progress at this stage, cavity creation engineering progress, oil pad pressure, wellhead water injection pressure, wellhead nitrogen pressure, gas-water interface depth, and pressure at the bottom-hole gas-water interface.

[0004] Acquire cavity data, calculate the effective volume of the salt cavity based on the cavity data; obtain the formula for the volume of soluble salt underground and the static volume based on the effective volume of the salt cavity;

[0005] The progress of cavity construction and the progress of cavity construction project in this stage were calculated based on the volume of soluble salt underground.

[0006] The wellhead injection pressure and oil pad pressure were calculated based on the solvent interface depth and friction head loss; the wellhead nitrogen pressure was calculated based on the principle of liquid column pressure balance at the connecting point.

[0007] The gas-water interface depth is calculated based on the static volume formula; the pressure at the bottom gas-water interface is calculated based on the gas-water interface depth.

[0008] In a preferred embodiment, calculating the effective volume of the saline cavity based on the cavity creation data includes: V t =V s +V i ; V i =V t ×α; Vb =V i ×β; V f =V t -V b ;

[0009] Among them, V t V is the total volume of the salt cavity. s V is the volume of soluble salts underground. i V is the volume of the underground insoluble matter before it expands. b V is the volume of the insoluble matter after expansion, β is the coefficient of expansion, α is the content of insoluble matter, and V f This is the effective volume of the salt cavity.

[0010] In a preferred embodiment, the method for obtaining the volume of soluble salt underground is as follows:

[0011] Among them, C b The concentration of the extracted brine, ρ s Density of underground pure salt, V s V is the volume of soluble salt underground. c To extract the salt volume from the surface brine, V i V is the volume of the underground insoluble matter before it expands. f This is the effective volume of the salt cavity.

[0012] In a preferred embodiment, the static volume formula includes the total volume formula of the salt cavity and the volume formula of the insoluble matter before expansion.

[0013] The formula for the total volume of the salt cavity is:

[0014] The formula for the volume of insoluble matter before expansion is:

[0015] Among them, V t V is the total volume of the salt cavity. i This represents the volume of the insoluble matter before expansion.

[0016] In a preferred embodiment, the method for calculating the cavity construction progress and cavity construction project progress based on the volume of soluble salt underground includes:

[0017] First, calculate the effective volume of the solar cavity based on the volume of soluble salt underground:

[0018] Where, ΔV f V is the effective volume of the cavity. s ΔV represents the volume of soluble salts underground;s The volume of dissolved salt on that day;

[0019] The cumulative effective volume of the cavity in this stage is obtained by summing the effective volume of the cavity accumulated over the days.

[0020] Where, ΔV f V represents the effective volume of the cavity created during this stage. f The cumulative effective cavity volume for this stage, where n is the number of days;

[0021] The cumulative effective cavity volume V in this stage f The cavity construction progress for this stage is obtained by comparing the pre-designed volume with the volume of this stage: θ1=Vf / Vd;

[0022] Among them, V f The cumulative effective cavity volume for this stage; Vd is the designed volume for this stage; θ1 is the cavity construction progress for this stage.

[0023] The ratio of the total effective volume of the underground salt cavity to the total designed volume of the upper salt cavity represents the progress of the cavity construction project. θ2=(Vf+Vs) / Vdt;

[0024] Where Vt is the total effective volume of the underground salt cavity, θ2 is the progress of the cavity construction project, and V f V represents the cumulative effective cavity volume for each stage. s Vdt represents the volume of soluble salt underground, and Vdt represents the total designed volume of the salt cavity.

[0025] In a preferred embodiment, the wellhead injection pressure includes both forward circulation injection pressure and reverse circulation injection pressure; the method for calculating the wellhead injection pressure based on head loss along the flow path is as follows:

[0026] Positive cycle: P iw正 =P deb +ρ in gh f1 +ρ anu gh f2 +(ρ anu -ρ in )gH in ;

[0027] Anti-loop: P iw反 =P deb +ρ in gh f1 +ρ anu gh f2 +(ρ in -ρ anu )gH in ;

[0028] Among them, P deb Wellhead brine discharge pressure; h f1 Head loss along the cavity tube; h f2 For the head loss along the inner and outer annulus; ρ in ρ is the density of the fluid inside the tube. anu H represents the annular fluid density of the inner and outer pipes. in The depth of the inner tube is given by g; g is the acceleration due to gravity; P is the acceleration due to gravity. iw正 For positive circulation water injection pressure, P iw负 This is the reverse circulation water injection pressure.

[0029] In a preferred embodiment, the oil pad pressure includes the forward circulation oil pad pressure and the reverse circulation oil pad pressure; the method for calculating the wellhead injection pressure based on the head loss along the flow path is as follows:

[0030] Positive cycle: P oil Positive = P iw正 -ρ in gh f1 +ρ in gH in -ρ anu g(H in -H GB )-ρ oil gH GB );

[0031] Anti-loop: P oil =P deb +ρ oil gH GB -ρ in gh f1 -ρ oil gH GB ;

[0032] Among them, P oil正 For the circulating oil pad pressure, P oil负 For the reverse circulation oil pad pressure, ρ oil H is the density of diesel fuel. GB The depth of the solvent barrier interface.

[0033] In a preferred embodiment, the method for calculating the wellhead nitrogen pressure based on the principle of pressure balance of the liquid column at the connected point includes:

[0034] Nitrogen pressure includes positive cycle nitrogen pressure and reverse cycle nitrogen pressure;

[0035] The positive circulation nitrogen pressure is:

[0036] The reverse circulation nitrogen pressure is:

[0037] Where, γ g Nitrogen relative density, Average compressibility factor of downhole nitrogen Average temperature of nitrogen in the well, P ig正 For positive cycle nitrogen pressure, P ig负 This is the pressure of the reverse-cycle nitrogen gas.

[0038] In a preferred embodiment, the gas-water interface depth includes the forward circulation gas-water interface depth and the reverse circulation gas-water interface depth; the method for calculating the depth at the bottom gas-water interface based on the wellhead discharge pressure is as follows:

[0039] make By performing a Taylor series expansion on the static volume formula, we obtain the positive cyclic expansion formula and the negative cyclic expansion formula.

[0040] Positive cyclic expansion formula:

[0041] Anti-loop expansion formula:

[0042] Solving the positive and negative loop expansion formulas separately yields:

[0043] Where, ρ 环空 For, ρ 内管 For, P 注气 For, α is the nitrogen pressure correction factor, H 界面正 H represents the depth at the gas-water interface at the bottom of the positive circulation well. 界面负 This refers to the depth at the gas-water interface at the bottom of the negative circulation well.

[0044] In a preferred embodiment, the method for calculating the pressure at the bottom gas-water interface based on the gas-water interface depth includes: Pinterface = (Pdischarge + ρannulargh) f2 +ρ annular gH interface); P 界面负 =(P 排卤 +ρ 内管 gh f1 +ρ 内管 gH 界面 );

[0045] Among them, P 界面正 For the positive circulation gas-water interface pressure, P 界面反 P is the pressure at the reverse circulation steam-water interface. 排卤For the brine discharge pressure, ρ 环空 H is the density of the annular liquid column. 界面 ρ is the depth of the gas-water interface at the bottom of the well. 内管 This refers to the density of the fluid column inside the cavity.

[0046] The beneficial effects of this invention are:

[0047] (1) By introducing the tracking of parameters such as the cavity-building progress and cavity-building engineering progress at this stage, and combining it with the calculation of the effective volume of the salt cavity, this method can more accurately reflect the actual state of cavity building. This method not only considers traditional parameters such as displacement and water injection pressure, but also adds monitoring of key parameters such as oil pad pressure, wellhead nitrogen pressure, and gas-water interface depth, providing a more comprehensive data foundation;

[0048] (2) By calculating the volume of soluble salts underground and applying it to the assessment of the cavity-making progress and cavity-making project progress in this stage, the present invention can better control the cavity-making process, ensure that the cavity shape meets the design expectations, reduce the possibility of insufficient cavity volume in a single well, and use the depth of the solvent interface and the head loss along the flow path to determine the wellhead water injection pressure and oil pad pressure, and calculate the wellhead nitrogen pressure based on the principle of liquid column pressure balance at the connection point, which helps to prevent safety hazards caused by pressure imbalance and improve the safety and stability of gas storage operation.

[0049] (3) This invention calculates the pressure at the gas-water interface at the bottom of the well based on the gas-water interface depth. This method enhances the predictive ability for accidents that may occur during the cavity-building process, allowing managers to take measures in advance to avoid or reduce the impact of potential risks. It helps ensure that the actual storage capacity of the gas storage facility reaches or approaches the design value, thereby improving the operating efficiency and economic benefits of the gas storage facility, and also provides more accurate decision support for subsequent maintenance and management. This application calculates the volume of soluble salt underground by considering key parameters such as the effective volume of the salt cavity, the expansion coefficient of underground insoluble matter, the concentration of produced brine, and the density of underground pure salt. Then, based on these data and parameters, a mathematical model is used to further determine the effective daily cavity-building volume and accumulate it to obtain the cumulative cavity-building volume of the current stage. This method improves the accuracy of cavity-building volume prediction, helps optimize the salt cavity development process, improves resource utilization efficiency, and reduces resource waste. Attached Figure Description

[0050] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0051] Figure 1 This is a schematic diagram of a cavity dynamic tracking and analysis method according to an embodiment of the present invention;

[0052] Figure 2This is a schematic diagram of the structure of a computer system used to implement the methods, systems, and devices of this application. Detailed Implementation

[0053] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0054] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0055] This invention provides a dynamic tracking and analysis method for cavity construction. The parameters tracked by the method include: cavity construction progress at this stage, cavity construction progress, oil pad pressure, wellhead water injection pressure, wellhead nitrogen pressure, gas-water interface depth, and pressure at the bottom-hole gas-water interface.

[0056] Acquire cavity data, calculate the effective volume of the salt cavity based on the cavity data; obtain the formula for the volume of soluble salt underground and the static volume based on the effective volume of the salt cavity;

[0057] The progress of cavity construction and the progress of cavity construction project in this stage were calculated based on the volume of soluble salt underground.

[0058] The wellhead injection pressure and oil pad pressure were calculated based on the solvent interface depth and friction head loss; the wellhead nitrogen pressure was calculated based on the principle of liquid column pressure balance at the connecting point.

[0059] The gas-water interface depth is calculated based on the volume formula; the pressure at the bottom gas-water interface is calculated based on the gas-water interface depth.

[0060] To more clearly explain the cavity dynamic tracking analysis method of the present invention, the following is combined with... Figure 1 The method for dynamic tracking and analysis of cavity formation according to embodiments of the present invention will be described in detail.

[0061] The method for dynamic tracking and analysis of cavity formation according to the first embodiment of the present invention is described in detail below:

[0062] Acquire cavity data, calculate the effective volume of the salt cavity based on the cavity data; obtain the formula for the volume of soluble salt underground and the static volume based on the effective volume of the salt cavity;

[0063] In this embodiment, the cavity creation data includes at least one of the following: well information, cavity creation daily report, sonar cavity measurement data, and cavity creation design parameters.

[0064] The well information includes at least one of the following: well name, well type, structural location, artificial well bottom, thickness, and insoluble matter; the cavity design parameters include at least one of the following: cavity stage, start time, end time, previous sonar volume, circulation method, injection volume, stage time, remaining total cavity time, designed oil-water interface depth, inner tube depth, outer tube depth, designed stage volume, designed total volume, remarks, average insoluble matter content, expansion coefficient, pure salt density, solvent type, solvent density, inner tube absolute roughness, and responsible person; the sonar cavity measurement data includes at least one of the following: sonar cavity measurement number, cavity measurement time, and cavity volume parameters.

[0065] In this embodiment, calculating the effective volume of the saline cavity based on the cavity creation data includes:

[0066] In this embodiment, the total volume V of the salt cavern gas storage tank is... t It consists of two parts. The first is the effective volume V of the salt cavity. f The first is the volume measured by sonar; the effective volume can be used to store natural gas. The second is the volume of insoluble matter V after expansion. b V, the insoluble matter before swelling i and insoluble matter in the pores of brine V p Composition. The volume of insoluble matter after expansion is an ineffective volume and cannot be used for gas storage.

[0067] Total volume of salt cavity V t The volume V of soluble salt underground s Volume composition V of underground insoluble matter before expansion i ; V t =V s +V i ;

[0068] In this embodiment, the volume V of the insoluble matter before expansion is... i The total volume V of the salt cavity t Multiply by the insoluble content α, where the insoluble content is obtained from the well logging curve, as shown in the formula: V i =V t ×α;

[0069] In this embodiment, the insoluble substance V before underground expansion i After absorbing brine, it expands and forms an insoluble substance V. b The expansion coefficient is β, and the relationship between the three is as follows: V b =V i ×β;

[0070] In this embodiment, the effective volume V of the salt cavity f V is the total volume of the salt cavity. tSubtract the insoluble volume V after expansion b : V f =V t -V b ;

[0071] Among them, V t V is the total volume of the salt cavity. s V is the volume of soluble salts underground. i V is the volume of the underground insoluble matter before it expands. b V is the volume of the insoluble matter after expansion, β is the coefficient of expansion, α is the content of insoluble matter, and V f This is the effective volume of the salt cavity.

[0072] In this embodiment, when water is injected to create a cavity, the soluble salt V underground... s It dissolves in water to form brine, a portion of which is extracted to the surface. The volume of this salt underground is V. c The other part remains within the underground salt cavity, existing within the effective volume V of the salt cavity. f V in the pores of the insoluble matter after expansion p In the middle. The swelling process of insoluble matter can be understood as brine entering the pores of the insoluble matter, causing the volume of the insoluble matter to increase. And V p It refers to the volume difference before and after the insoluble substance swells. Based on the above analysis, the amount of soluble salt V in the underground is obtained. s The volume method is as follows:

[0073] Among them, C b The concentration of the extracted brine, ρ s Density of underground pure salt, V s V is the volume of soluble salt underground. c For, V i V is the volume of the underground insoluble matter before it expands. f This is the effective volume of the salt cavity.

[0074] The static volume formula includes the formula for the total volume of the salt cavity and the formula for the volume of insoluble matter before expansion; the static volume formula based on the effective volume of the salt cavity includes:

[0075] The formula for the total volume of the salt cavity is:

[0076] The formula for the volume of insoluble matter before expansion is:

[0077] Among them, V t V is the total volume of the salt cavity. i V is the volume of the insoluble matter before expansion. f This is the effective volume of the salt cavity.

[0078] The progress of cavity construction and the progress of cavity construction project in this stage were calculated based on the volume of soluble salt underground.

[0079] In this embodiment, the method for calculating the cavity construction progress and cavity construction project progress based on the volume of soluble salt underground includes:

[0080] First, calculate the effective volume of the solar cavity based on the volume of soluble salt underground:

[0081] Where, ΔV f V is the effective volume of the cavity. s ΔV represents the volume of soluble salts underground; s The volume of dissolved salt on that day;

[0082] The cumulative effective volume of the cavity in this stage is obtained by summing the effective volume of the cavity accumulated over the days.

[0083] Where, ΔV f V represents the effective volume of the cavity created during this stage. f The cumulative effective cavity volume for this stage, where n is the number of days;

[0084] The cumulative effective cavity volume V in this stage f The cavity construction progress for this stage is obtained by comparing the pre-designed volume with the volume of this stage: θ1=Vf / Vd;

[0085] Among them, V f The cumulative effective cavity volume for this stage; Vd is the designed volume for this stage; θ1 is the cavity construction progress for this stage.

[0086] Compare the previous sonar volume Vs with the cumulative effective cavity volume V in this phase. f The sum of the underground salt cavity is the total effective volume Vt of the underground salt cavity, and the ratio of the total effective volume of the underground salt cavity to the total designed volume of the upper salt cavity is the progress of the cavity construction project. θ2=(Vf+Vs) / Vdt;

[0087] Where Vt is the total effective volume of the underground salt cavity, θ2 is the progress of the cavity construction project, and V f V represents the cumulative effective cavity volume for each stage. s Vdt represents the volume of soluble salt underground, and Vdt represents the total designed volume of the salt cavity.

[0088] The yellow color at the top of the cavity indicates nitrogen or diesel as a solvent barrier, blue indicates brine, and light blue indicates fresh water. Before cavity construction, nitrogen or diesel is injected into the annulus of the production casing and the outer cavity construction tube to the designed depth, forming a solvent barrier layer to protect the cavity top from corrosion by the fresh brine. Fresh water is injected into the inner cavity construction tube, and brine is discharged from the annulus of the outer and inner cavity construction tubes, achieving positive circulation cavity construction. Alternatively, fresh water can be injected into the annulus of the outer and inner cavity construction tubes, and brine can be extracted from the inner cavity construction tube, achieving reverse circulation nitrogen or diesel as a solvent barrier for cavity construction.

[0089] The wellhead injection pressure and oil pad pressure were calculated based on the solvent interface depth and friction head loss.

[0090] In this embodiment, the pressure and depth are calculated using a mathematical model of solvent-inhibiting wellhead pressure and depth.

[0091] The cavity well can be viewed as a U-shaped pipe, with the inner pipe as one side of the U-shape and the annulus between the inner and outer pipes as the other side. The depth of the inner pipe is H. in Taking the connection point of the U-shaped pipe as an example, the wellhead injection pressure P is derived based on the principle of liquid column pressure balance at the connection point. iw Wellhead injection pressure includes both forward circulation injection pressure and reverse circulation injection pressure; the method for calculating wellhead injection pressure based on head loss along the flow path is as follows:

[0092] Positive cycle: P iw正 =P deb +ρ in gh f1 +ρ anu gh f2 +(ρ anu -ρ in )gH in ;

[0093] Anti-loop: P iw反 =P deb +ρ in gh f1 +ρ anu gh f2 +(ρ in -ρ anu )gH in ;

[0094] Among them, P deb Wellhead brine discharge pressure; h f1 Head loss along the cavity tube; h f2 For the head loss along the inner and outer annulus; ρ in ρ is the density of the fluid inside the tube. anu H represents the annular fluid density of the inner and outer pipes. in The depth of the inner tube is given by g; g is the acceleration due to gravity; P is the acceleration due to gravity.iw正 For positive circulation water injection pressure, P iw负 This is the reverse circulation water injection pressure.

[0095] In this embodiment, the inner tube of the cavity is considered as one side of a U-shaped tube, and the annulus between the outer tube of the cavity and the production casing is considered as the other side of the U-shaped tube. The oil-water interface depth H GB Treating the connection point of the U-shaped pipe as the point of connection, the calculated head loss along the pipe h is used. f1 Substituting the values, we can obtain the oil pad pressure, including the forward circulation oil pad pressure and the reverse circulation oil pad pressure; the method for calculating the oil pad pressure based on the head loss along the flow path is as follows:

[0096] Positive cycle: P oil Positive = P iw正 -ρ in gh f1 +ρ in gH in -ρ anu g(H in -H GB )-ρ oil gH GB );

[0097] Anti-loop: P oil =P deb +ρ oil gH GB -ρ in gh f1 -ρ oil gH GB ;

[0098] Among them, P oil正 For the circulating oil pad pressure, P oil负 For the reverse circulation oil pad pressure, ρ oil H is the density of diesel fuel. GB The depth of the solvent barrier interface.

[0099] The wellhead nitrogen pressure was calculated based on the principle of liquid column pressure balance at the connected points.

[0100] In this embodiment, the brine discharge channel (for positive circulation, the inner tube; for reverse circulation, the inner and outer annulus) can be considered as one side of the U-shaped tube, and the annulus between the outer tube and the production casing can be considered as the other side of the U-shaped tube. The gas-water interface depth H GB This is used as a connection point in a U-shaped tube, forming another U-shaped tube. Based on the principle of liquid column pressure balance at the connection point, the wellhead nitrogen pressure is derived. The nitrogen pressure includes both forward and reverse circulation nitrogen pressures. The method for calculating the wellhead nitrogen pressure is as follows:

[0101] The positive circulation nitrogen pressure is:

[0102] The reverse circulation nitrogen pressure is:

[0103] Where, γ g Nitrogen relative density, Average compressibility factor of downhole nitrogen Average temperature of nitrogen in the wellbore: 321 K; P ig正 For positive cycle nitrogen pressure, P ig负 This is the pressure of the reverse-cycle nitrogen gas.

[0104] Assume the pressure on the downhole nitrogen is equal to the wellhead pressure P. 注气 Pressure P at the gas-water interface at the bottom of the well 界面 The average value can be derived from the gas law, which gives the volume V of nitrogen under standard conditions. 地面 The calculation formula is as follows:

[0105] Where: V 地面 It is the volume of nitrogen under standard ground conditions, in meters. 3 V 井下 It is the volume of the downhole nitrogen gas cushion, P 界面 It is the pressure at the gas-water interface at the bottom of the well, in Pa; T 地面 It is the ground temperature, 288K; P s It is the ground pressure, 101×10 4 Pa.

[0106] In this embodiment, the head loss along the friction is h f1 h f2 The Darcy-Weschbach formula in fluid mechanics was used for calculation, and the result was derived as follows:

[0107] Where, λ in The friction coefficient along the inner tube, λ anu Here, Hot is the friction coefficient along the annulus between the inner and outer tubes, and Hot is the depth of the outer tube in meters; D is the friction coefficient along the annulus between the inner and outer tubes. ininn Inner tube inner diameter, m; D inot Inner tube outer diameter, m; D otinn Outer pipe inner diameter, m; Q water injection discharge rate, m 3 / h.

[0108] Friction coefficient λ and Reynolds number R e related:

[0109] Where μ is the fluid viscosity, mP·s; ρ is the fluid density, kg / m³. 3v is the fluid velocity, in m / s 2 μ is the fluid viscosity, in mPa·s; D is the diameter of the circular pipe, in m. For the inner pipe, D = D ininn For annular flows between inner and outer pipes, the equivalent diameter can be introduced to transform the annular flow into circular pipe flow with equivalent resistance for calculation, D = D otinn -D ininn .

[0110] First, based on the Reynolds number R... e Determine the flow pattern, and then calculate λ using the corresponding formula. The Reynolds number Re calculation formula is shown in Table 1. Δ represents the absolute roughness of the tubing, in mm; the empirical value for the Jintan area is 0.035 mm for the inner tube and 1.2 mm for the annular space between the inner and outer tubes. ε represents the relative roughness of the tubing. Table 1

[0111] By comparing the calculated oil pad pressure or air pad pressure with the actual field monitoring values, it is possible to effectively determine whether the solvent barrier interface has shifted, thus ensuring the monitoring of the solvent barrier interface position. Finally, the diesel solvent barrier interface depth can be obtained as follows.

[0112] Positive circulation: h injection depth = (P) disel -P Inner pipe water injection pressure +Pf-(ρ) w -ρ b )gh inner tube depth / 10 6 / ((ρ b - ρ blanket ) / 10 6 );

[0113] Anti-loop: h_oil injection depth = (Pdisel - P_inner tube discharge pressure - Pf) / ((ρb - ρblanket) / 10 6 );

[0114] Among them, h 注油深度 For the injection depth of diesel fuel inhibitor, P disel P is the pressure of the diesel fuel solvent. 内管注水压力 P is the water injection pressure in the intracavitary tube. 内管排卤压力 ρ is the pressure at which the brine is discharged from the cavity tube. b ρ is the density of the diesel fuel inhibitor. blanket This represents the density of the solvent-resistant pad.

[0115] The gas-water interface depth is calculated based on the volume formula; the pressure at the bottom gas-water interface is calculated based on the gas-water interface depth.

[0116] The gas-water interface depth includes the forward circulation gas-water interface depth and the reverse circulation gas-water interface depth; the method for calculating the depth of the gas-water interface at the bottom of the well based on the wellhead discharge pressure is as follows:

[0117] make By performing a Taylor series expansion on the static volume formula, we obtain the positive cyclic expansion formula and the negative cyclic expansion formula.

[0118] Positive cyclic expansion formula:

[0119] Anti-loop expansion formula:

[0120] Solving the positive and negative loop expansion formulas separately yields:

[0121] Where, ρ 环空 For, ρ 内管 For, P 注气 For, α is the nitrogen pressure correction factor, H 界面正 H represents the depth at the gas-water interface at the bottom of the positive circulation well. 界面负 This refers to the depth at the gas-water interface at the bottom of the negative circulation well.

[0122] In this embodiment, the method for calculating the pressure at the bottom gas-water interface based on the gas-water interface depth includes: Pinterface = (Pdischarge + ρannulargh) f2 +ρ annular gH interface); P 界面负 =(P 排卤 +ρ 内管 gh f1 +ρ 内管 gH 界面 );

[0123] Among them, P 界面正 For the positive circulation gas-water interface pressure, P 界面反 P is the pressure at the reverse circulation steam-water interface. 排卤 For the brine discharge pressure, ρ 环空 H is the density of the annular liquid column. 界面 ρ is the depth of the gas-water interface. 内管 This refers to the density of the fluid column inside the cavity.

[0124] In this embodiment, a mathematical model of solvent-inhibiting wellhead pressure and depth is used to predict the oil pad pressure and the solvent-inhibiting interface depth during the cavity-building process. This mathematical model comprehensively considers key factors such as wellhead pressure, depth, solvent properties, oil pad hydrodynamic behavior, and solvent-inhibiting interface changes during the cavity-building process to predict the oil pad pressure and solvent-inhibiting interface depth.

[0125] In this embodiment, various data generated in real time during the cavity creation process are collected, such as cavity volume, cavity creation progress, oil pad pressure, solvent barrier interface depth, wellhead pressure, and key parameters related to changes in subsurface conditions. This data comes not only from real-time monitoring equipment but also from historical data and design parameters acquired during construction. Based on this data and the predicted values, a comprehensive dynamic tracking and analysis framework is constructed.

[0126] In this embodiment, firstly, based on real-time pressure data during the cavity-building process, the wellhead pressure is predicted using the mathematical model of the solvent-inhibiting wellhead pressure. For example, the rate of change of wellhead pressure is calculated based on wellhead pressure, depth D, solvent density, fluid viscosity μ, and solvent flow rate v during the cavity-building process. Next, the oil pad pressure is calculated based on the relationship between wellhead depth D and solvent interface depth.

[0127] Secondly, based on the dynamic relationship between oil pad pressure and solvent barrier interface depth, the interface depth is determined using the mathematical model of the solvent barrier interface depth. For example, considering the fluid motion characteristics of the solvent barrier during the cavity creation process and the influence of depth changes on the interface position, the depth change of the solvent barrier interface is calculated; all depth changes within the current stage are summed to obtain the solvent barrier interface depth during the cavity creation process.

[0128] This application establishes a mathematical model of wellhead pressure and depth based on the solvent-inhibiting agent, and comprehensively analyzes the dynamic changes in wellhead pressure, oil pad dynamics, and the solvent-inhibiting interface. This model enables accurate prediction of oil pad pressure and solvent-inhibiting interface depth during the cavity-building process. This method effectively improves the accuracy of parameter prediction during cavity-building, provides a scientific basis for the stability of cavity-building operations, and thus helps optimize the cavity-building process, improve resource utilization, and ensure safe and efficient construction progress.

[0129] During dynamic tracking and analysis, a pre-constructed mathematical model for cavity creation dynamic tracking and analysis is used to compare actual monitoring data with theoretical predictions. This comparative analysis allows for real-time assessment of deviations during the cavity creation process. For example, when the actual oil pad pressure deviates significantly from the predicted value, adjustments can be made to the construction operation in a timely manner to ensure the stability of the cavity creation process. Simultaneously, the real-time monitoring and comparison of the solvent-inhibiting interface depth with calculation results can reveal changes in underground conditions, such as the cavity expansion rate or the distribution of the solvent-inhibiting agent, thus providing guidance for construction.

[0130] Furthermore, by combining the current cavity volume with the cumulative cavity volume data, the cavity construction progress can be dynamically tracked. For example, by comparing the current daily cavity volume with the predicted volume, potential delays or advancements in construction progress can be identified. Based on this information, the construction team can flexibly adjust the cavity construction plan, optimize resource allocation and personnel scheduling, and ensure the project is completed on schedule.

[0131] Based on real-time changes in oil pad pressure and solvent interface depth, dynamic analysis using the mathematical model can further predict potential risks during cavity creation, such as cavity collapse, solvent failure, or abnormal increases in oil pad pressure. These dynamic analyses help improve the safety of the cavity creation process and prevent major accidents.

[0132] Based on various input cavity-building data, including well information, daily cavity-building reports, sonar cavity measurement data, and cavity-building design parameters, the cavity-building data is stored and organized, presented in the form of graphs and tables to facilitate user monitoring of the cavity-building status. Simultaneously, based on the cavity-building data, mathematical models are used to calculate predicted values ​​such as cavity volume, cavity-building progress, and fitted oil pad pressure. Integrating these data yields dynamic tracking and analysis results. In some embodiments, cavity-building adjustments can be made based on predicted values, or compared with actual values ​​to identify abnormal cavity-building phenomena.

[0133] Presenting the results of dynamic tracking analysis. First, input the cavity data. In some embodiments, this data can be presented through a software interface. For example, click on Drilling Information on the main software interface to enter the well information input interface. Input information includes well name, well type, structural location, artificial bottom, thickness, insoluble matter, etc. Insoluble matter information can be automatically imported from an Excel spreadsheet and can be displayed in the sonar cavity shape interface. After inputting, click OK to save. After establishing the well information, other relevant information for that well can be input.

[0134] In the cavity design parameter input interface, first select the well number, then click "Add Stage" and enter the cavity design parameters for this stage. Enter the cavity stage, start time, end time, previous sonar volume, circulation method, injection volume, stage time, remaining total cavity time, design oil-water interface depth, inner tube depth, outer tube depth, design stage volume, design total volume, remarks, average insoluble content, expansion coefficient, pure salt density, solvent type, solvent density, inner tube absolute roughness, and responsible person. Click the "Export" button to export the cavity parameters. Alternatively, click the "Delete" button to delete a stage. Selecting any cavity stage and clicking the "Insert" button will insert a new cavity stage below it.

[0135] In the cavity stomata daily report import interface, you can click the "Select File" button to choose a cavity stomata daily report file for import, or click "Select Path," and the software will automatically recognize the cavity stomata daily report file. Clicking the well number allows you to change the corresponding well for import, or you can click "Modify Well Number" to modify all well numbers. After confirming that the correspondence between the cavity stomata daily report and the well numbers is accurate, click "Upload" to save.

[0136] Next, the cavity creation data or calculated data are displayed in the form of tables, charts, graphs, and progress tables to enable users to perform cavity creation analysis and monitoring.

[0137] The daily report display interface for single-well cavity construction allows you to view the daily cavity construction report for each well. You can select a single well by clicking the well number, select a time period by selecting the start and end dates, and then select the desired daily cavity construction report by clicking the date in the lower left corner. This interface allows you to monitor daily cavity construction parameters, such as oil pad pressure, brine concentration, and cavity volume. It provides timely updates on the daily cavity construction status of each well.

[0138] The single-well cavity creation daily report display interface organizes the cavity creation data into a row list format, which helps users monitor changes in cavity creation data over a period of time. Clicking the well number selects the well to display, selecting the start and end dates adjusts the display period, and checking the cavity creation parameters selects the cavity creation data to be displayed. Clicking the filter button allows filtering of the displayed cavity creation data; for example, selecting the injection fluid volume (point 9) filters out data outside the range of 1-1000. This embodiment of the application's interface includes a data export function; clicking the central EXCEL chart exports the displayed data to an EXCEL file, facilitating data analysis using other software.

[0139] The daily chart monitoring interface for single-well cavity construction displays cavity production data as curves, and also shows data calculated using mathematical models, such as solvent pressure fitting. Users can also click the "Custom" button to combine and calculate cavity construction data and display it as a curve. Selecting the well number and the time period for display, along with checking the parameters below, allows users to adjust the range of the curve's vertical axis by clicking the scale button. This interface displays cavity construction production data for a single well over a period of time as a curve, enabling users to easily observe the changing patterns of a specific cavity construction parameter over a period, assess the cavity construction status, and better monitor cavity construction.

[0140] The cavity construction progress monitoring interface allows monitoring of the cycle method, previous sonar volume, stage cavity construction volume, stage cavity construction progress, total cavity construction volume, and project progress. The cavity construction progress is displayed as a progress bar for easier understanding. Clicking the refresh button refreshes the cavity construction data, or clicking the EXCEL chart exports the displayed data to an EXCEL file. Clicking the filter well number button selects the well numbers to display. During cavity construction progress monitoring, when a stage cavity construction progress approaches 100%, that stage is nearing completion, and preparations for well closure and sonar cavity measurement should be made in advance. When the overall cavity construction progress approaches 100%, the cavity construction project for that well is nearing completion, and preparations for sonar cavity measurement and injection-production completion should be made in advance.

[0141] The sonar shape monitoring interface displays the cavity shape of a single well from a single sonar measurement or multiple sonar measurements, facilitating cavity shape monitoring. Clicking the well number selects the well to display; clicking the sonar file displays a single sonar file; or pressing CTRL+clicking the sonar file selects multiple sonar files for display. The sonar shape graph displays the cavity radius on the horizontal axis and the cavity depth on the vertical axis. The right side of the graph also shows the sonar measurement number, measurement time, and cavity volume parameters. Clicking the angle progress bar selects the azimuth angle for the sonar shape display; checking the insoluble matter button displays the distribution of insoluble matter; and checking the distance measurement button performs distance measurements.

[0142] The sonar cavity scheduling interface automatically schedules single-well cavity plans according to the completion time sequence of cavity construction in each single-well stage, and displays them in the form of calendar markers for easy scheduling by the user. This application also provides a cavity morphology correction method, which includes the following steps:

[0143] Obtain dynamic tracking and analysis results. First, input cavity creation data. Well information includes well name, well location coordinates, insoluble matter distribution, etc.; daily cavity creation report files are automatically read to obtain brine discharge concentration, water injection discharge rate, brine discharge rate, etc.; sonar logging data files; cavity creation design parameters are input, including cavity creation design parameters: cavity creation stage, circulation mode, injection volume, stage time, design oil-water interface depth, outer tube depth, inner tube depth, design stage volume, design total volume, average insoluble matter content, insoluble matter expansion coefficient, pure salt density, solvent type, solvent density, inner tube absolute roughness, etc.

[0144] Next, data charts are displayed. The charts mainly include well location map display, single-chamber daily report display, single-chamber daily parameter statistics display, single-chamber daily chart display, cavity construction progress display, sonar cavity shape display, oil-water interface test report, and oil-water interface test chart.

[0145] Simultaneously, the calculation performs parameter fitting and parameter combination. Functions include oil pad pressure or air pad pressure fitting, cavity volume fitting, and cavity parameter combination calculation. By comparing theoretical calculation values ​​with actual values, cavity parameters can be monitored.

[0146] Finally, the system automatically monitors the cavity parameters. Monitoring conditions for these parameters can be set, and the system will automatically prompt the user to adjust the parameters if the actual cavity parameters do not meet these conditions.

[0147] In some embodiments, the dynamic tracking analysis results can be obtained using the above-described cavity creation dynamic tracking analysis method, which will not be elaborated further here.

[0148] Finally, cavity morphology correction can be performed. When the cavity volume does not reach the design value or the insoluble interlayer fails to collapse, resulting in deformities or dissolution at the bottom of the cavity, appropriate positive circulation adjustments are necessary. For example, taking well JT3 in a certain area as an example, the fourth sonar result showed that the cavity volume was 12,000 m³ less than the design value. 3 If reverse circulation is used, the lower cavity cannot be effectively expanded because the water injection point is at the top. Therefore, forward circulation is used in the next stage, lowering the inner tube to the bottom of the cavity for expansion. Numerical simulations show that, with the same cavity diameter, the final cavity volume can be increased by 25825.2 m³. 3 The ninth sonar reading in well JT4 revealed a rock ridge formed by insoluble interlayers at a depth of 1,110 m. During subsequent cavity construction stages, the cavity casing was lowered to this depth, and positive circulation was used for repeated repairs, ultimately dissolving the rock ridge. Therefore, appropriate use of positive circulation can effectively repair and expand the cavity.

[0149] This application utilizes dynamic tracking and analysis to acquire real-time data on various parameters during cavity construction. Combined with results from sonar cavity shape monitoring and oil-water interface testing, it can promptly identify issues such as insufficient cavity volume and failure of insoluble interlayers to collapse. Based on this, cavity construction parameters are monitored through parameter fitting and combined calculations, and the system automatically prompts the user for adjustments when necessary. Furthermore, by employing adjustment methods such as positive circulation, it effectively corrects problems such as cavity bottom deformities and partial dissolution, significantly improving the cavity expansion effect. For example, numerical simulations and actual sonar logging data show that the application of positive circulation can increase cavity volume and eliminate rock ridge problems caused by insoluble interlayers, thereby achieving precise repair and optimization of the cavity morphology and improving overall cavity construction efficiency and stability.

[0150] This application, by comprehensively utilizing real-time data and predicted values, employs a dynamic tracking and analysis model for cavity creation to conduct real-time dynamic monitoring and analysis, effectively improving the accuracy, stability, and safety of cavity creation construction. Simultaneously, the feedback from real-time data supports engineering decision-making, enabling the cavity creation project to proceed efficiently and smoothly under dynamic conditions. This dynamic tracking and analysis method provides an important tool for optimizing and managing the cavity creation process, significantly improving resource utilization efficiency and project management flexibility. Furthermore, by establishing mathematical models for calculating and simulating various parameters, this application compares the calculation results with actual on-site results, enabling timely detection of cavity creation anomalies and ensuring cavity creation quality.

[0151] Although the steps in the above embodiments are described in the above order, those skilled in the art will understand that in order to achieve the effect of this embodiment, different steps do not need to be executed in such an order. They can be executed simultaneously (in parallel) or in a reverse order. These simple variations are all within the protection scope of this invention.

[0152] The second embodiment of the cavity-building dynamic tracking and analysis system of the present invention tracks the following parameters: cavity-building progress at this stage, cavity-building engineering progress, oil pad pressure, wellhead water injection pressure, wellhead nitrogen pressure, gas-water interface depth, and pressure at the bottom-hole gas-water interface.

[0153] The data acquisition module is used to acquire cavity creation data, calculate the effective volume of the salt cavity based on the cavity creation data, and obtain the underground soluble salt volume and static volume formula based on the effective volume of the salt cavity.

[0154] The first calculation module is used to calculate the cavity construction progress and cavity construction project progress at this stage based on the volume of soluble salt underground.

[0155] The second calculation module is used to calculate the wellhead water injection pressure and oil pad pressure based on the solvent interface depth and friction head loss; and to calculate the wellhead nitrogen pressure based on the principle of liquid column pressure balance at the connecting point.

[0156] The third calculation module is used to calculate the gas-water interface depth based on the static volume formula; and to calculate the pressure at the gas-water interface at the bottom of the well based on the gas-water interface depth.

[0157] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the system described above can be found in the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0158] It should be noted that the cavity dynamic tracking and analysis system provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present invention can be further decomposed or combined. For example, the modules in the above embodiments can be merged into one module, or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing the various modules or steps and are not considered as an improper limitation of the present invention.

[0159] An electronic device according to a third embodiment of the present invention includes: at least one processor; and a memory communicatively connected to at least one of the processors; wherein the memory stores instructions executable by the processor, the instructions being executed by the processor to implement the above-described cavity dynamic tracking analysis method.

[0160] A computer-readable storage medium according to a fourth embodiment of the present invention stores computer instructions, which are executed by the computer to implement the above-described cavity dynamic tracking and analysis method.

[0161] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the storage device and processing device described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0162] Those skilled in the art will recognize that the modules and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. The programs corresponding to the software modules and method steps can be placed in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art. To clearly illustrate the interchangeability of electronic hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the invention.

[0163] The following is for reference. Figure 2 It shows a schematic diagram of the structure of a computer system for implementing the methods, systems, and devices of this application. Figure 2 The server shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0164] like Figure 2 As shown, the computer system includes a Central Processing Unit (CPU) 601, which can perform various appropriate actions and processes based on programs stored in Read Only Memory (ROM) 602 or programs loaded from storage section 608 into Random Access Memory (RAM) 603. The RAM 603 also stores various programs and data required for system operation. The CPU 601, ROM 602, and RAM 603 are interconnected via a bus 604. An Input / Output (I / O) interface 605 is also connected to the bus 604.

[0165] The following components are connected to I / O interface 605: an input section 606 including a keyboard, mouse, etc.; an output section 607 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 608 including a hard disk, etc.; and a communication section 609 including a network interface card such as a LAN (Local Area Network) card, modem, etc. The communication section 609 performs communication processing via a network such as the Internet. A drive 610 is also connected to I / O interface 605 as needed. A removable medium 611, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on drive 610 as needed so that computer programs read from it can be installed into storage section 608 as needed.

[0166] Specifically, according to embodiments of this disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 609, and / or installed from removable medium 611. When the computer program is executed by central processing unit (CPU) 601, it performs the functions defined in the methods of this application. It should be noted that the computer-readable medium described above in this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in connection with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on a computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0167] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0168] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0169] The terms “first”, “second”, etc., are used to distinguish similar objects, not to describe or indicate a specific order or sequence.

[0170] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0171] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for dynamic tracking and analysis of cavity formation, characterized in that, The parameters tracked by the method include: the current stage of cavity construction progress, cavity construction progress, oil pad pressure, wellhead water injection pressure, wellhead nitrogen pressure, gas-water interface depth, and pressure at the bottom-hole gas-water interface. Acquire cavity data, calculate the effective volume of the salt cavity based on the cavity data; obtain the formula for the volume of soluble salt underground and the static volume based on the effective volume of the salt cavity; The progress of cavity construction and the progress of cavity construction project in this stage were calculated based on the volume of soluble salt underground. The wellhead injection pressure and oil pad pressure were calculated based on the solvent interface depth and friction head loss; the wellhead nitrogen pressure was calculated based on the principle of liquid column pressure balance at the connecting point. The gas-water interface depth is calculated based on the static volume formula; the pressure at the bottom gas-water interface is calculated based on the gas-water interface depth.

2. The method for dynamic tracking and analysis of cavity formation according to claim 1, characterized in that, The effective volume of the saline cavity, calculated based on the cavity creation data, includes: V t =V s +V i V i =V t ×α; V b =V i ×β; V f =V t -V b ; Among them, V t V is the total volume of the salt cavity. s V is the volume of soluble salts underground. i V is the volume of the underground insoluble matter before it expands. b V is the volume of the insoluble matter after expansion, β is the coefficient of expansion, α is the content of insoluble matter, and V f This is the effective volume of the salt cavity.

3. The method for dynamic tracking and analysis of cavity formation according to claim 2, characterized in that, The method for obtaining the volume of soluble salts underground is as follows: Among them, C b The concentration of the extracted brine, ρ s Density of underground pure salt, V s V is the volume of soluble salt underground. c To extract the salt volume from the surface brine, V i V is the volume of the underground insoluble matter before it expands. f This is the effective volume of the salt cavity.

4. The method for dynamic tracking and analysis of cavity formation according to claim 3, characterized in that, The static volume formulas include the formula for the total volume of the salt cavity and the formula for the volume of insoluble matter before expansion; The formula for obtaining the static volume based on the effective volume of the salt cavity includes: The formula for the total volume of the salt cavity is: The formula for the volume of insoluble matter before expansion is: Among them, V t V is the total volume of the salt cavity. i V is the volume of the insoluble matter before expansion. f This is the effective volume of the salt cavity.

5. The method for dynamic tracking and analysis of cavity formation according to claim 4, characterized in that, Methods for calculating the cavity construction progress and cavity construction project progress at this stage based on the volume of soluble salts underground include: First, calculate the effective volume of the solar cavity based on the volume of soluble salt underground: Where, ΔV f V is the effective volume of the cavity. s ΔV represents the volume of soluble salts underground; s The volume of dissolved salt on that day; The cumulative effective volume of the cavity in this stage is obtained by summing the effective volume of the cavity accumulated over the days. Where, ΔV f V represents the effective volume of the cavity created during this stage. f The cumulative effective cavity volume for this stage, where n is the number of days; The cumulative effective cavity volume V in this stage f The cavity construction progress for this stage is obtained by comparing the pre-designed volume with the volume of this stage: θ1=Vf / Vd; Among them, V f The cumulative effective cavity volume for this stage; Vd is the designed volume for this stage; θ1 is the cavity construction progress for this stage. The ratio of the total effective volume of the underground salt cavity to the total designed volume of the upper salt cavity represents the progress of the cavity construction project. θ2=(Vf+Vs) / Vdt; Where Vt is the total effective volume of the underground salt cavity, θ2 is the progress of the cavity construction project, and V f V represents the cumulative effective cavity volume for each stage. s Vdt represents the volume of soluble salt underground, and Vdt represents the total designed volume of the salt cavity.

6. The method for dynamic tracking and analysis of cavity formation according to claim 5, characterized in that, Wellhead injection pressure includes both forward circulation injection pressure and reverse circulation injection pressure; the method for calculating wellhead injection pressure based on head loss along the flow path is as follows: Positive cycle: P iw正 =P deb +ρ in gh f1 +ρ anu gh f2 +(ρ anu -ρ in )gH in ; Anti-loop: P iw反 =P deb +ρ in gh f1 +ρ anu gh f2 +(ρ in -ρ anu )gH in ; Among them, P deb Wellhead brine discharge pressure; h f1 Head loss along the cavity tube; h f2 For the head loss along the inner and outer annulus; ρ in ρ is the density of the fluid inside the tube. anu H represents the annular fluid density of the inner and outer pipes. in The depth of the inner tube is given by g; g is the acceleration due to gravity; P is the acceleration due to gravity. iw正 For positive circulation water injection pressure, P iw负 This is the reverse circulation water injection pressure.

7. The method for dynamic tracking and analysis of cavity formation according to claim 6, characterized in that, Oil pad pressure includes forward circulation oil pad pressure and reverse circulation oil pad pressure; the method for calculating oil pad pressure based on head loss along the flow path is as follows: Positive cycle: P oil正 =P iw正 -ρ in gH f1 +ρ in gH in -ρ anu g(H in -H GB )-ρ oil gH GB ); Anti-loop: P oil反 =P deb +ρ oil gH GB -ρ in gh f1 -ρ oil gH GB ; Among them, P oil正 For the circulating oil pad pressure, P oil负 For the reverse circulation oil pad pressure, ρ oil H is the density of diesel fuel. GB The depth of the solvent barrier interface.

8. The method for dynamic tracking and analysis of cavity formation according to claim 7, characterized in that, Methods for calculating wellhead nitrogen pressure based on the principle of liquid column pressure balance at connected points include: Nitrogen pressure includes positive cycle nitrogen pressure and reverse cycle nitrogen pressure; The positive circulation nitrogen pressure is: The reverse circulation nitrogen pressure is: Where, γ g Nitrogen relative density, Average compressibility factor of downhole nitrogen Average temperature of nitrogen in the well, P ig正 For positive cycle nitrogen pressure, P ig负 This is the pressure of the reverse-cycle nitrogen gas.

9. The method for dynamic tracking and analysis of cavity formation according to claim 8, characterized in that, The gas-water interface depth includes the forward circulation gas-water interface depth and the reverse circulation gas-water interface depth; the method for calculating the depth of the gas-water interface at the bottom of the well based on the wellhead discharge pressure is as follows: make By performing a Taylor series expansion on the static volume formula, we obtain the positive cyclic expansion formula and the negative cyclic expansion formula. Positive cyclic expansion formula: Anti-loop expansion formula: Solving the positive and negative loop expansion formulas separately yields: Where, ρ 环空 ρ is the density of the annular liquid column. 内管 P is the density of the fluid column in the cavity. 注气 H represents the nitrogen pressure injected at the wellhead, α is the nitrogen pressure correction factor, and H 界面正 H represents the depth at the gas-water interface at the bottom of the positive circulation well. 界面负 This refers to the depth at the gas-water interface at the bottom of the negative circulation well.

10. The method for dynamic tracking and analysis of cavity formation according to claim 9, characterized in that, Methods for calculating the pressure at the bottom-of-well gas-water interface based on the gas-water interface depth include: P 界面正 =(P 排卤 +ρ 环空 gh f2 +ρ 环空 gH 界面 ); P 界面负 =(P 排卤 +ρ 内管 gh f1 +ρ 内管 gH 界面 ); Among them, P 界面正 For the positive circulation gas-water interface pressure, P 界面反 P is the pressure at the reverse circulation steam-water interface. 排卤 For the brine discharge pressure, ρ 环空 H is the density of the annular liquid column. 界面 ρ is the depth at the gas-water interface. 内管 This refers to the density of the fluid column inside the cavity.

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