Shale oil physical model manufacturing method

Abstract

The invention relates to the technical field of seismic exploration, in particular to a shale oil physical model manufacturing method. The method comprises the following steps: acquiring simulation block information; determining a physical model similarity coefficient, and converting according to the similarity coefficient to obtain each stratum parameter of the physical model; and manufacturing a thin layer, a crack mold and a crack block, putting the physical model material into the mold, embedding the crack block, and curing to obtain a crack area physical model. The method is simple and reliable, and can simulate various complex lithofacies.

Description

Technical Field

[0001] The present invention relates to the technical field of seismic exploration, and in particular to a method for making a shale oil physical model. Background Art

[0002] Shale oil reservoirs have many lithofacies types and complex spatial combinations. Seismic reflections usually correspond to large sets of mudstone sections. The seismic response characteristics and differences of favorable lithofacies and different lithofacies combinations are not yet clear, making reservoir description difficult.

[0003] Seismic physical simulation methods have played an important role in seismic exploration forward modeling. With the in-depth development of domestic seismic exploration, the requirements for physical simulation are getting higher and higher, and the simulation technology is also developing accordingly. From the early structural physical simulation to lithological simulation, in recent years, simulations of various special reservoirs combined with rock physics have been carried out.

[0004] CN109206092B discloses a phase-change sandstone reservoir physical model. The method for preparing the phase-change sandstone reservoir physical model comprises: mixing the components in the amounts uniformly and then pressing and solidifying to obtain the phase-change sandstone reservoir physical model, comprising: mixing quartz sands of different mesh sizes; mixing silicate cement with the mixed quartz sand to obtain a quartz sand mixture; mixing a water reducer, a defoamer and water to obtain a water mixture; mixing the water mixture with the quartz sand mixture; adding the mixed materials into a mold for pressing, and taking out the pressed sandstone mold after the completion. The method comprises the steps of: forming the model, spraying water for curing, and waiting for the model to be completely solidified; placing the solidified and dried model and the melted phase change paraffin wax in a vacuum box to saturate the model with vacuum, so that the phase change paraffin wax completely fills the pores of the model, and cooling the model so that the phase change material is converted into a solid state; mixing the epoxy resin and the curing agent evenly, and then evacuating and degassing the model; placing the treated sandstone model in the mold, and then pouring the degassed epoxy resin and the curing agent into the mold, so that the sandstone model is completely wrapped and sealed by the epoxy resin; taking out the model after the epoxy resin is completely solidified, drilling holes at both ends of the model and inserting catheters, so as to obtain the phase change sandstone reservoir physical model.

[0005] CN114426410B discloses a method for preparing a vug-type reservoir seismic physical model by using a vug-type reservoir seismic physical model material. The vug-type reservoir seismic physical model material comprises, by weight, 15-25 parts of kaolin, 20-100 parts of water, 1000 parts of quartz sand, 60-100 parts of epoxy resin, and 5-20 parts of curing agent. The method comprises the following steps: S1: uniformly mixing kaolin and water and freezing them into an ice-like solid; S2: making the ice-like solid into vug models of different shapes and sizes and freezing them for standby use; S3: mixing the epoxy resin and the curing agent; Preheating is performed separately, and the preheated epoxy resin and curing agent are mixed with the quartz sand to obtain a raw material mixture, and the raw material mixture is divided into multiple equal parts; S4: pretreating the mold; adding one portion of the raw material mixture to the pretreated mold and flattening it, placing the hole model processed by step S2 on the flattened raw material mixture, and placing another portion of the raw material mixture on the hole model processed by step S2 and flattening it to obtain a pre-pressed material; S5: pressing and curing the pre-pressed material to obtain the hole-type reservoir seismic physical model.

[0006] The existing physical models can simulate a single lithofacies and can only simulate strata with one fracture density, generally horizontal fractures or vertical fractures; it is difficult to simulate fractures in different lithofacies. Summary of the invention

[0007] In order to solve the above-mentioned deficiencies of the prior art, the present invention provides a method for making a shale oil physical model. The method of the present invention can simulate different fracture density formations using different proportions of silicone rubber and epoxy resin according to actual fracture parameters, and at the same time, by using different proportions of physical model materials to simulate different lithofacies, the simulation accuracy of the physical model can be improved.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] The present invention provides a method for preparing a shale oil reservoir physical model, the method comprising the following steps:

[0010] Acquire simulation block information; determine the similarity coefficient of the physical model, and convert the parameters of each formation of the physical model according to the similarity coefficient; make thin layers, crack molds and crack blocks, put the physical model material into the mold, embed the crack block, and obtain the physical model of the crack area after solidification.

[0011] Furthermore, the simulation block information obtained includes the simulation area, simulation layer, simulation area lithofacies, fracture spatial distribution and formation parameters.

[0012] Furthermore, the formation parameters include formation thickness, formation velocity, formation density and formation depth.

[0013] Furthermore, the physical model material is composed of the following raw materials and their weight parts: 30-100 parts of epoxy resin, 0-50 parts of silicon micropowder, and 0-40 parts of talc.

[0014] The material ratio can simulate a variety of different lithofacies strata, and the simulated lithofacies are shown in Table 1.

[0015] Furthermore, the crack block is prepared using epoxy resin and silicone rubber as materials, and the specific method includes:

[0016] Using epoxy resin as the matrix, the silicone rubber sheets are evenly distributed in the matrix according to the calculated volume ratio, and a layer of cracks is formed after curing; the above step is repeated many times to form a crack sheet stack, the crack sheet stack is cut into sheets, the cut crack sheets are stacked with epoxy resin, and cured to form crack blocks.

[0017] Furthermore, the volume ratio of silicone rubber to epoxy resin is 1:1-10.

[0018] Furthermore, the thickness of the crack sheet stack is 1-2 cm.

[0019] Furthermore, the method also includes the steps of performing morphological testing and correction on the physical model of the crack area, and the model correction accuracy is 0.1-0.5mm.

[0020] The present invention also provides a shale oil reservoir physical model produced by the above method.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] The method described in the present invention can simulate a variety of complex lithofacies by adjusting the ratio of epoxy resin, silicon micropowder, and talcum powder model materials, and simulate different fracture density formations with different ratios of silicone rubber and epoxy resin; the method described in the present invention also controls the morphological quality of the physical model by using a three-dimensional morphological laser tester. The method described in the present invention can improve the simulation accuracy of the physical model and realize the diversity of the simulation object. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A crack block diagram provided for an embodiment of the present application.

[0024] Figure 2 This is a diagram for preparing the fracture zone model provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations and / or combinations thereof.

[0027] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0028] Example 1

[0029] (1) Simulation area: 110 km 2 The simulation depth is 2000m-5000m. The main lithofacies types in the simulation area are organic-rich layered gray shale, organic-rich layered gray shale, organic-rich laminated cryptocrystalline gray shale, and organic-rich laminated cryptocrystalline gray shale. The fracture zone is distributed in the south and north of the work area. The direction of the fracture in the south is parallel to the direction of the nearby fault, northeast; the direction of the fracture in the north is parallel to the direction of the nearby fault, northwest. The formation velocity is 2600m / s-4000m / s.

[0030] (2) The spatial similarity ratio between the shale oil physical model and the simulation area is 1:10000, and the velocity similarity ratio is 1:1.4. After conversion, the model area is 1.1m 2 , 1.05m long from east to west, 1.05m long from north to south, model formation velocity 1800m / s-2900m / s. Design fracture morphology and spatial distribution.

[0031] (3) Model material preparation: epoxy resin, silica powder and talcum powder are mixed in proportion to make a low-speed material. The test block speed meets the model design requirements. The mass ratio of epoxy resin, silica powder and talcum powder, the test block speed, and the corresponding simulated petrographic facies are shown in Table 1.

[0032] (4) Use 3D printing technology to print out the main layers of the model.

[0033] (5) Preparation of crack blocks: smear epoxy resin matrices with thicknesses of 0.2 mm, 0.4 mm, 0.6 mm, and 0.8 mm on the workbench respectively, and evenly distribute the silicone rubber sheets in the matrix according to the calculated volume ratio of 1:2.33. After curing, a single layer of cracks is formed. The previous step is repeated multiple times to form a 1 cm thick crack sheet stack. The crack sheet is cut into 7 cm*7 cm squares, and the multiple layers of crack sheets are stacked with epoxy resin. Finally, the crack blocks are cured to form cutting and polishing according to the crack morphology in step (2).

[0034] (6) The model is cast layer by layer. The uncured model material in step (3) is poured into the physical model mold layer by layer at the designed speed, and a layer of physical model is obtained after curing. The crack blocks in step (5) are embedded in the uncured target layer according to the designed spatial distribution, and a physical model of the crack area is formed after curing.

[0035] (7) After each layer of the physical model is completed, a 3D morphology laser tester is used to perform morphology testing on the physical model and perform error analysis to determine whether the model meets the design requirements. If it meets the design requirements, the next layer of the physical model is produced. If it does not meet the design requirements, the previous step is repeated until the model is completed.

[0036] The difference between Example 2 to Example 14 and Example 1 is that the proportions of the components of the model materials are different, as shown in Table 1 for details.

[0037] Table 1 Material ratio of each embodiment model

[0038]

[0039]

[0040] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing a shale oil reservoir physical model, characterized in that: The method comprises the following steps: Acquire simulation block information; determine the similarity coefficient of the physical model, and convert the parameters of each formation of the physical model according to the similarity coefficient; make thin layers, crack molds and crack blocks, put the physical model material into the mold, embed the crack block, and obtain the physical model of the crack area after solidification.

2. The method for preparing a shale oil reservoir physical model according to claim 1, wherein: The simulation block information obtained includes the simulation area, simulation layer, simulation area lithofacies, fracture spatial distribution and formation parameters.

3. The method for preparing a shale oil reservoir physical model according to claim 1 or 2, characterized in that: The formation parameters include formation thickness, formation velocity, formation density and formation depth.

4. The method for preparing a shale oil reservoir physical model according to claim 1, wherein: The physical model material is composed of the following raw materials and their weight parts: 30-100 parts of epoxy resin, 0-50 parts of silicon micropowder, and 0-40 parts of talc.

5. The method for preparing a shale oil reservoir physical model according to claim 1, wherein: The crack block is prepared using epoxy resin and silicone rubber as materials, and the specific method includes: Using epoxy resin as the matrix, the silicone rubber sheets are evenly distributed in the matrix according to the calculated volume ratio, and a layer of cracks is formed after curing; the above step is repeated many times to form a crack sheet stack, the crack sheet stack is cut into sheets, the cut crack sheets are stacked with epoxy resin, and cured to form crack blocks.

6. The method for preparing a shale oil reservoir physical model according to claim 5, characterized in that: The volume ratio of silicone rubber to epoxy resin is 1:1-10.

7. The method for preparing a shale oil reservoir physical model according to claim 5, wherein: The thickness of the crack sheet stack is 1-2 cm.

8. The method for preparing a shale oil reservoir physical model according to claim 1, wherein: The method also includes the steps of performing morphological testing and correction on the physical model of the crack area, and the model correction accuracy is 0.1-0.5mm.

9. A shale oil reservoir physical model produced by the method according to any one of claims 1 to 8.

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