Clay model establishment method and sand control screen model performance online testing method

Abstract

The present invention belongs to the technical field of oil and gas production and provides a method for establishing a clay model and an online testing method for the performance of a sand screen model. The method for establishing a clay model includes establishing agglomerate base particles formed by connecting at least two clay base models; adding a preset size of adsorption viscosity on the surface of the agglomerate base particles; piling up a number of agglomerate base particles to form a pure clay model; wherein the connection force between the clay base models in the agglomerate base particles is greater than the adsorption viscosity on the surface of the agglomerate base particles. The present invention uses the agglomerate base particles as the most basic particles in the clay model to form a large agglomerate with a larger size and richer morphology, thereby better simulating and restoring the mechanical morphology of clay particles when agglomerating and dispersing when the clay model moves, so that the movement of the clay model is more in line with the actual situation.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas exploitation, and in particular relates to a clay model establishment method and a sand control screen pipe model performance online testing method. Background Art

[0002] Studying the migration of solid particles is of great significance for guiding the design of sand screens and improving the efficiency of oil and gas production. In the process of oil and gas production, due to the complex and changeable downhole conditions and the inability to directly observe the movement of solid particles downhole, most existing technologies use numerical simulation technology to study the migration of solid particles. Solid particles (such as rocks and sand particles) are generally accompanied by the flow of clay and fluids during migration. Clay modeling is very difficult because it has the characteristics of small particle size, layered, viscous and elastic, and easy agglomeration and dispersion during migration.

[0003] The existing clay model is generally composed of a number of basic particle models with clay properties. This type of clay model has a limited degree of clay restoration. When the model is used to conduct online testing of the performance of sand control screens, the test results are often quite different from reality. Summary of the invention

[0004] In view of the above defects or shortcomings, the present invention provides a clay model establishment method and a sand control screen model performance online testing method, aiming to solve the technical problem that the existing clay model has a limited degree of clay reduction.

[0005] To achieve the above object, the present invention provides a method for establishing a clay model, wherein the method for establishing a clay model comprises:

[0006] S100: establishing agglomerate package basic particles formed by connecting at least two clay basic models;

[0007] S200: adding a preset adsorption viscosity force on the surface of the base particles of the agglomeration package;

[0008] S300: stacking a plurality of agglomeration package base particles to form a pure clay model;

[0009] Among them, the bonding force between the clay-based models within the agglomerate-packed basic particles is greater than the adsorption viscosity on the surface of the agglomerate-packed basic particles.

[0010] In an embodiment of the present invention, S100: the step of establishing agglomerate base particles formed by connecting at least two clay base models specifically includes:

[0011] S110: Building clay base model;

[0012] S120: selecting a preset number of clay basic models, and adding intra-package connection keys between the selected clay basic models, so that the connected clay basic models are aggregated to form agglomerated package basic particles.

[0013] In an embodiment of the present invention, after S120: selecting a preset number of clay base models, adding intra-package connecting keys between the selected clay base models so that the connected clay base models are aggregated to form agglomerated package basic particles, the step further includes:

[0014] S130: setting the contact mode of two clay base models connected by any intra-pack connecting bonds in the agglomerated pack base particles to overlapping contact, and setting the maximum depth of the overlapping contact.

[0015] In an embodiment of the present invention, S110: the step of establishing a clay base model specifically includes:

[0016] S111: Establish the first particle model;

[0017] S112: setting the density, Poisson's ratio, Young's modulus, restitution coefficient, static friction coefficient, and dynamic friction coefficient of the first particle model so that the first particle model has the same physical properties as clay.

[0018] In an embodiment of the present invention, the particle size of the first particle model is less than or equal to 2 micrometers.

[0019] In an embodiment of the present invention, after S300: piling a plurality of agglomerate base particles to form a pure clay model, the clay model building method further includes:

[0020] S310: Establish non-clay particle model;

[0021] S320: Mixing the non-clay particle model with the agglomerate package base particles in the pure clay model.

[0022] In an embodiment of the present invention, S310: the step of establishing a non-clay particle model specifically includes:

[0023] S311: Establish the second particle model;

[0024] S312: setting the density, Poisson's ratio, Young's modulus, restitution coefficient, static friction coefficient and dynamic friction coefficient of the second particle model so that the second particle model has the physical properties of solid particles.

[0025] In an embodiment of the present invention, the adsorption viscosity of the surface of the non-clay particle model is zero.

[0026] To achieve the above object, the present invention further provides an online testing method for the performance of a sand control screen model, wherein the online testing method for the performance of a sand control screen model comprises:

[0027] S400: Building a clay model using the clay model building method described above;

[0028] S500: Place the clay model into the fluid model;

[0029] S600: applying momentum to the fluid model so that the fluid model carries the clay model and flows through the sand control screen model along a preset path;

[0030] S700: When the clay model flows through the sand control screen model, monitor the blockage change process of the sand control screen model;

[0031] S800: Evaluate the performance of sand control screen models based on the plugging process.

[0032] In an embodiment of the present invention, S500: before placing the clay model into the fluid model, the method for online testing the performance of the sand control screen model further includes:

[0033] S410: Establish non-clay particle model;

[0034] S420: Mixing the non-clay particle model into the clay model.

[0035] Through the above technical solution, the clay model building method provided by the embodiment of the present invention has the following beneficial effects:

[0036] Due to the adsorption and viscosity force on the surface of the agglomerate bag basic particles, when several agglomerate bag basic particles move with the fluid model, the agglomerate bag basic particles can be adsorbed and agglomerated with each other to form an unstable and larger agglomerate bag, and some large agglomerate bags with unstable forms can be dispersed by the fluid during the migration process to be restored to agglomerate bag basic particles. Furthermore, since each agglomerate bag basic particle contains multiple clay basic models, the multiple clay basic models in the agglomerate bag basic particle can be adsorbed with adjacent agglomerate bag basic particles respectively to form a large agglomerate bag with a multi-layer morphology, and the multi-layer large agglomerate bags can collide with each other to further form agglomerate bags of different forms, or disperse and restore into agglomerate bag basic particles. That is, the clay model established by this method has richer morphological changes when it moves. In summary, the present invention uses the agglomerate base particles as the most basic particles in the clay model to form a large agglomerate with a larger size and richer morphology, so that the mechanical morphology of the clay particles during agglomeration and dispersion can be better simulated and restored during the movement of the clay model, making the movement of the clay model more in line with the actual situation.

[0037] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide an understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention. In the accompanying drawings:

[0039] Figure 1 is a general flow chart of a clay model building method according to an embodiment of the present invention;

[0040] Figure 2 is a specific flow chart of step S100 according to an embodiment of the present invention;

[0041] Figure 3 is a specific flow chart of step S110 according to an embodiment of the present invention;

[0042] Figure 4 is a flowchart after step S300 according to an embodiment of the present invention;

[0043] Figure 5 is a specific flow chart of step S310 according to an embodiment of the present invention;

[0044] Figure 6 is a general flow chart of a method for online testing performance of a sand control screen model according to an embodiment of the present invention;

[0045] Figure 7 is a flowchart between step S400 and step S500 according to an embodiment of the present invention;

[0046] Figure 8 Schematic diagram of the structure of the agglomerated basic particles in the pure clay model according to an embodiment of the present invention.

[0047] Description of Reference Numerals

[0048] 1 agglomeration pack base particles DETAILED DESCRIPTION

[0049] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0050] The clay model building method of the present invention is described below with reference to the accompanying drawings.

[0051] The present invention provides a method for establishing a clay model. Figure 1 and Figure 8 As shown, the clay model building method includes:

[0052] S100: establishing an agglomerate package basic particle 1 formed by connecting at least two clay basic models;

[0053] S200: adding a preset adsorption viscosity to the surface of the agglomeration package base particles 1;

[0054] S300: stacking a plurality of agglomeration package base particles 1 to form a pure clay model;

[0055] The bonding force between the clay-based models in the agglomerate-packed basic particles 1 is greater than the adsorption viscosity on the surface of the agglomerate-packed basic particles 1 .

[0056] Due to the adsorption viscosity on the surface of the agglomerate bag basic particles 1, when several agglomerate bag basic particles 1 move with the fluid model, the agglomerate bag basic particles 1 can be adsorbed and agglomerated with each other to form an unstable and larger agglomerate bag, and some large agglomerate bags with unstable forms can be dispersed by the fluid during the migration process to be restored to the agglomerate bag basic particles 1. Furthermore, since each agglomerate bag basic particle 1 contains multiple clay basic models, the multiple clay basic models in the agglomerate bag basic particle 1 can be adsorbed with adjacent agglomerate bag basic particles 1 respectively to form a large agglomerate bag with a multi-layer morphology, and the multi-layer large agglomerate bags can collide with each other to further form agglomerate bags of different forms, or disperse and restore into agglomerate bag basic particles 1. That is, the clay model established by the present method has richer morphological changes when it moves. In summary, the present invention uses the agglomerate base particles 1 as the most basic particles in the clay model to form a large agglomerate package with a larger size and richer morphology, thereby better simulating and restoring the mechanical morphology of the clay particles during agglomeration and dispersion during the movement of the clay model, making the movement of the clay model more in line with the actual situation.

[0057] It should be noted that if the clay base model is used as the basic particle of the clay model, after the clay base model is aggregated into a certain size of agglomerate package, continuing to adsorb a new clay base model will cause the old clay base model to fall off, resulting in the size of the agglomerate package being limited, and the agglomeration form of the agglomerate package being single. The agglomerate package produced by the present invention not only breaks the size limitation, but also has more diverse forms, thereby being able to more accurately restore the bonding and aggregation process during clay migration.

[0058] In the embodiment of the present invention, the coupling force needs to be greater than the maximum dispersion force of the fluid, and the adsorption viscosity force needs to be less than the maximum dispersion force of the fluid.

[0059] In the embodiment of the present invention, when the basic particles 1 of the agglomerate package are mutually adsorbed and agglomerated into a larger agglomerate package, a connecting bond is generated between the basic particles 1 of the agglomerate package. However, the stability of the connecting bond is poor and it is easy to cause breakage when impacted by a fluid.

[0060] like Figure 2 and Figure 8As shown, in an embodiment of the present invention, S100: the step of establishing agglomerate base particles 1 formed by connecting at least two clay base models specifically includes:

[0061] S110: Building clay base model;

[0062] S120: selecting a preset number of clay basic models, and adding intra-package connecting keys between the selected clay basic models, so that the connected clay basic models are aggregated to form agglomerated package basic particles 1.

[0063] After establishing several clay-based models, a preset number of clay-based models are selected, and the parameters are adjusted to make them contact each other. By adjusting the surface viscosity parameters of the contact area between the clay-based models, a stable intra-package connection bond can be formed between the clay-based models. Under the action of the intra-package connection bond and the adsorption viscosity of the surface of the agglomerated package base particles 1, the bonding properties of the actual clay can be better restored.

[0064] It should be noted that the agglomerate base particles 1 can have various shapes, such as a central rotationally symmetrical plum blossom shape, a four-leaf clover shape, or a chain shape.

[0065] like Figure 2 and Figure 8 As shown, in an embodiment of the present invention, after S120: selecting a preset number of clay base models, adding intra-package connecting keys between the selected clay base models so that the connected clay base models are aggregated to form agglomerated package basic particles 1, the steps further include:

[0066] S130: setting the contact mode of two clay base models connected by any intra-pack connecting bond in the agglomerated pack base particles 1 to overlapping contact, and setting the maximum depth of the overlapping contact.

[0067] like Figure 8 As shown, taking a 2-micron spherical clay base model as an example, when setting the contact mode of the clay base model, the contact mode of the clay base model can be set to overlap contact, and the maximum radial overlap depth of overlap contact is set to 0.29 microns. The contact depth of the clay base model can vary between the maximum depth and 0. The purpose of this design is to reflect the layered compressibility characteristics when the agglomeration package basic particles 1 aggregate to form a large agglomeration package, so as to more accurately restore the mechanical form of the clay being compressed when passing through smaller pore throat gaps and screen meshes. Due to the presence of the connecting key in the package, it can ensure that the clay base model in the agglomeration package basic particles 1 always remains in contact, preventing the agglomeration package basic particles 1 from being dispersed.

[0068] It should be noted that in the existing clay model that uses the clay base model as the basic particle, since the clay base models are independent of each other, when the clay base models are agglomerated, the connecting bonds are formed only through surface contact, and the clay base models cannot overlap, resulting in this type of agglomeration package being unable to be compressed.

[0069] like Figure 3 As shown, in an embodiment of the present invention, S110: the step of establishing a clay base model specifically includes:

[0070] S111: Establish the first particle model;

[0071] S112: setting the density, Poisson's ratio, Young's modulus, restitution coefficient, static friction coefficient, and dynamic friction coefficient of the first particle model so that the first particle model has the same physical properties as clay.

[0072] For example, when building a clay foundation model, the parameters can be set as shown in the following table:

[0073] density 1800 Poisson's ratio 0.45 Young's modulus 0.384 Coefficient of restitution 0.3 Static friction coefficient 0.15 Dynamic friction coefficient 0.01

[0074] In the embodiment of the present invention, the particle size of the first particle model is preferably less than or equal to 2 micrometers, so that the shape of the agglomerate base particle 1 is similar to the shape of the actual clay particle.

[0075] like Figure 4 As shown, in an embodiment of the present invention, S300: after a plurality of agglomerate base particles 1 are stacked to form a pure clay model, the clay model building method further includes:

[0076] S310: Establish non-clay particle model;

[0077] S320: Mixing the non-clay particle model with the agglomerate package base particles 1 in the pure clay model.

[0078] The non-clay particle model is mainly used to simulate solid particles such as rocks and quartz sand. When the solid particles in the underground formation move, they are generally accompanied by the flow of clay and fluid. Therefore, this method mixes the non-clay particle model into the pure clay model, so that the established clay model is closer to the actual situation.

[0079] like Figure 5 As shown, in an embodiment of the present invention, S310: the step of establishing a non-clay particle model specifically includes:

[0080] S311: Establish the second particle model;

[0081] S312: setting the density, Poisson's ratio, Young's modulus, restitution coefficient, static friction coefficient and dynamic friction coefficient of the second particle model so that the second particle model has the physical properties of solid particles.

[0082] In the embodiment of the present invention, the adsorption viscosity force on the surface of the non-clay particle model is 0 and is rigid. When the non-clay particle model moves with the agglomeration bag basic particle 1, due to the adsorption viscosity force on the surface of the agglomeration bag basic particle 1, the agglomeration bag basic particle 1 will unilaterally adsorb the agglomeration bag basic particle 1, and when forming a larger agglomeration bag, the agglomeration bag basic particles 1 are bidirectionally adsorbed.

[0083] like Figure 6 As shown, in order to achieve the above-mentioned purpose, the present invention also provides an online testing method for the performance of a sand control screen model, wherein the online testing method for the performance of a sand control screen model comprises:

[0084] S400: Building a clay model using the clay model building method described above;

[0085] S500: Place the clay model into the fluid model;

[0086] S600: applying momentum to the fluid model so that the fluid model carries the clay model and flows through the sand control screen model along a preset path;

[0087] S700: When the clay model flows through the sand control screen model, monitor the blockage change process of the sand control screen model;

[0088] S800: Evaluate the performance of sand control screen models based on the plugging process.

[0089] like Figure 7 As shown, in an embodiment of the present invention, S500: before placing the clay model into the fluid model, the online testing method for the performance of the sand control screen model further includes:

[0090] S410: Establish non-clay particle model;

[0091] S420: Mixing the non-clay particle model into the clay model.

[0092] The established clay model can be either a pure clay model or a mixed model of a pure clay model and a non-clay particle model. When it is necessary to study the anti-blocking performance of the sand screen for pure clay, the pure clay model can be placed in the fluid model, and momentum is applied to the fluid model so that the fluid carries the agglomerate base particles 1 through the sand screen model. As the agglomerate base particles 1 are retained in the sand screen, the sand control performance of the sand screen for pure clay can be reflected by monitoring the blockage changes of the sand screen model. Similarly, when it is necessary to study the sand control effect of the sand screen on mixed sandstone with clay, rock, and sand, the non-clay particle model can be mixed into the pure clay model to form a mixed model, and then placed in the fluid model for operation.

[0093] In the embodiment of the present invention, a pure clay model or a mixed model may include a single clay base model and clay base models with different numbers of agglomerated base particles 1 .

[0094] In summary, the online performance testing method of the present invention can get rid of the dependence on laboratory equipment, and the testing cost is very low. At the same time, only the parameters of the sand control screen model need to be adjusted to test the sand control performance of the sand control screen with different parameters, thereby providing guidance for the design of the sand control screen.

[0095] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0096] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0097] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0098] Although the embodiments of the present invention have been described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for establishing a clay model, characterized in that: The clay model building method comprises: Establishing agglomerated base particles (1) formed by connecting at least two clay base models; Adding a preset adsorption viscosity to the surface of the agglomerate base particles (1); Stacking a plurality of the agglomerate base particles (1) to form a pure clay model; Wherein, the bonding force between the clay base models in the agglomerate base particles (1) is greater than the adsorption viscosity on the surface of the agglomerate base particles (1); The bonding force is greater than the maximum dispersing force when the fluid moves the clay model, and the adsorption viscosity force is less than the maximum dispersing force of the fluid; The particle size of the clay base model is less than or equal to 2 microns.

2. The clay modeling method according to claim 1, characterized in that: The step of establishing the agglomerate base particles (1) formed by connecting at least two clay base models specifically comprises: Establishing the clay foundation model; A preset number of the clay basic models are selected, and intra-package connecting bonds are added between the selected clay basic models so that the connected clay basic models are aggregated to form the agglomerated package basic particles (1).

3. The clay modeling method according to claim 2, characterized in that: The step of selecting a preset number of the clay basic models and adding intra-package connecting bonds between the selected clay basic models so that the connected clay basic models are aggregated to form the agglomerated package basic particles (1) further includes: The contact mode of the two clay base models connected by any intra-pack connecting bond in the agglomerated pack base particle (1) is set to overlapping contact, and the maximum depth of the overlapping contact is set.

4. The clay modeling method according to claim 2, characterized in that: The steps of establishing the clay base model specifically include: Establish the first particle model; The density, Poisson's ratio, Young's modulus, restitution coefficient, static friction coefficient and dynamic friction coefficient of the first particle model are set so that the first particle model has the same physical properties as clay.

5. The clay modeling method according to any one of claims 1 to 4, characterized in that: The step after stacking a plurality of the agglomerate base particles (1) to form the pure clay model further includes: Build non-clay particle models; The non-clay particle model is mixed with the agglomerate base particles (1) in the pure clay model.

6. The clay modeling method according to claim 5, characterized in that: The steps to establish the non-clay particle model include: Establish a second particle model; The density, Poisson's ratio, Young's modulus, restitution coefficient, static friction coefficient and dynamic friction coefficient of the second particle model are set so that the second particle model has the physical properties of solid particles.

7. The clay modeling method according to claim 5, characterized in that: The adsorption viscosity of the surface of the non-clay particle model is 0.

8. A method for online testing of sand control screen model performance, characterized in that: The online testing method for the performance of the sand control screen model includes: Building a clay model using the clay model building method according to any one of claims 1 to 7; placing the clay model into a fluid model; Applying momentum to the fluid model so that the fluid model carries the clay model and flows through the sand control screen model along a preset path; When the clay model flows through the sand control screen model, monitoring the blockage change process of the sand control screen model; The performance of the sand control screen model is evaluated based on the blockage change process.

9. The method for online testing the performance of a sand control screen model according to claim 8, characterized in that: Before placing the clay model into the fluid model, the sand control screen model performance online testing method further includes: Build non-clay particle models; The non-clay particle model is mixed into the clay model.

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