Hole-type artificial core model and preparation method and application thereof

Abstract

The invention belongs to the field of seismic physical models, and discloses a hole type artificial core model and a preparation method and application thereof. The method comprises the following steps: uniformly mixing quartz sand and a cementing agent to obtain a cementing material; uniformly mixing the porous material with the cementing material to obtain a mixed material; injecting the mixed material into a mold, and sequentially pressing, curing, demolding and polishing to obtain a cured artificial rock core; mixing the cured artificial rock core with water to obtain a mixed system; carrying out vacuumizing treatment on the mixed system to enable water to permeate into the cured artificial rock core so as to obtain the artificial rock core with a hole structure; and drying the artificial rock core with the hole structure to obtain a hole type artificial rock core model. The hole-type artificial core model is good in sound wave penetrability and stable in wave velocity, and can be used for forward modeling method research of hole-type reservoir seismic physical models.

Description

Technical Field

[0001] The present invention belongs to the field of seismic physical models, and more specifically, relates to a hole-type artificial core model, a preparation method and an application thereof. Background Art

[0002] Seismic physical simulation is a method of making a geological model by scaling down the field geological structure and geological body in the laboratory, and using ultrasonic waves and the like to simulate seismic waves for forward simulation of field seismic exploration. In the 1950s, with the development of ultrasonic technology, seismic simulation experimental systems began to be established. With the continuous deepening of oil and gas exploration and development work, the exploration targets and development environments faced are becoming more and more complex, the exploration difficulty is increasing, and the refined requirements for exploration results are getting higher and higher, which means that higher requirements are also placed on the preparation technology of seismic physical models.

[0003] With the continuous deepening of oil and gas exploration and development work, the exploration targets and development environments faced are becoming more and more complex. In regions such as the northwest, southwest, and north China, the reservoir types are mostly fracture-type, hole-type, tight pore-type or a combination of multiple complex media. There are problems that the fluid seismic response characteristics of complex media reservoirs are not clear, resulting in unclear fluid prediction mechanisms. For conventional physical model making, composite materials that meet the requirements of acoustic wave propagation velocity can be prepared using high molecular materials such as epoxy resin and silicone rubber, and then complex two-dimensional or three-dimensional structure models can be made through processing, carving and other technologies, which meet the simulation research of complex surfaces and complex structures. However, the research on materials for simulating reservoirs containing hole structures is relatively weak. The simulation materials not only need to have certain porosity, holes and other characteristics, but also need to have the function of being saturated with fluid. The production methods and production processes are relatively complex, which has become a bottleneck restricting the further development of physical model technology. Therefore, selecting or formulating model materials that can be analogized with natural reservoir geology and making realistic reservoir models is one of the key issues for the success of seismic physical simulation technology. Summary of the Invention

[0004] The object of the present invention is to provide a hole-type artificial core model, a preparation method and an application thereof in view of the deficiencies of the prior art. The hole-type artificial core model of the present invention has good acoustic wave penetration and stable wave velocity, and can be used for the research of forward modeling methods of seismic physical models for hole-type reservoirs.

[0005] To achieve the above object, in a first aspect of the present invention, a method for preparing a hole-type artificial core model is provided, and the method includes the following steps:

[0006] S1: Mix quartz sand and a cementing agent evenly to obtain a cementing material;

[0007] S2: Mix hole materials with the cementing material evenly to obtain a mixed material;

[0008] S3: Inject the mixed material into a mold, and successively perform pressing, curing, demolding, and polishing to obtain a solidified artificial core.

[0009] S4: Mix the solidified artificial core with water to obtain a mixed system; perform a vacuum pumping treatment on the mixed system to allow water to penetrate into the solidified artificial core, thereby obtaining an artificial core with a pore structure.

[0010] S5: Perform a drying treatment on the artificial core with the pore structure to obtain the pore-type artificial core model.

[0011] The second aspect of the present invention provides a pore-type artificial core model prepared by the method described above.

[0012] The third aspect of the present invention provides an application of the pore-type artificial core model in the forward modeling method research of pore-type reservoir seismic physical models.

[0013] The beneficial effects of the technical solution of the present invention are as follows:

[0014] In view of the geological characteristics of special reservoirs containing pore structures, the present invention uses epoxy resin to bond quartz sand to simulate the reservoir, and dopes water-soluble particulate matters such as disintegrants, single crystals, and sodium chloride therein. After the core is solidified and formed, the particulate matters are dissolved in water and precipitated, so that pore structures can be left in the core, and a pore-type artificial core model is obtained.

[0015] Experimental results show that the pore-type artificial core model of the present invention has good acoustic wave penetrability and stable wave velocity, and can be used in the forward modeling method research of pore-type reservoir seismic physical models, providing a scientific basis for the correctness and reliability of geophysical characterization of pore-type reservoirs.

[0016] Other features and advantages of the present invention will be described in detail in the subsequent specific implementation section. Description of the Drawings

[0017] By describing the exemplary embodiments of the present invention in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present invention will become more obvious. Among them, in the exemplary embodiments of the present invention, the same reference numerals generally represent the same components.

[0018] Figure 1 Shows a flowchart of a method for preparing a pore-type artificial core model provided by Embodiments 1, 2, and 3 of the present invention.

[0019] Figure 2 Shows a CT scan slice of the pore-type artificial core model prepared in Embodiment 1 of the present invention.

[0020] Figure 3Shows the CT scan slices of the pore-type artificial core model prepared in the second embodiment of the present invention.

[0021] Figure 4 Shows the CT scan slices of the pore-type artificial core model prepared in the third embodiment of the present invention. Detailed implementation manners

[0022] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0023] The first aspect of the present invention provides a method for preparing a pore-type artificial core model, the method comprising the following steps:

[0024] S1: Mix quartz sand and a cementing agent evenly to obtain a cementing material;

[0025] S2: Mix the pore material with the cementing material evenly to obtain a mixed material;

[0026] S3: Inject the mixed material into a mold, and successively perform pressing, curing, demolding and polishing to obtain a cured artificial core;

[0027] S4: Mix the cured artificial core with water to obtain a mixed system; perform a vacuum treatment on the mixed system to allow water to penetrate into the cured artificial core to obtain an artificial core with a pore structure;

[0028] S5: Perform a drying treatment on the artificial core with the pore structure to obtain the pore-type artificial core model.

[0029] According to the present invention, preferably, the dosage ratio of the quartz sand, the cementing agent and the pore material is (80-120):(2-20):(9-15).

[0030] According to the present invention, preferably, the particle size of the quartz sand is 60-140 mesh, and preferably, the particle size of the quartz sand is 100 mesh.

[0031] In the present invention, as a preferred solution, the origin of the quartz sand is Hebei.

[0032] According to the present invention, preferably, the cementing agent comprises the following components in parts by weight: 6-10 parts of a first epoxy resin and 2-6 parts of a curing agent.

[0033] According to the present invention, preferably, the first epoxy resin is a bisphenol A type liquid epoxy resin with an epoxy equivalent of 184-195 g / mol and a viscosity of 10000-16000 mPas at 25°C.

[0034] According to the present invention, preferably, based on the total weight of the curing agent, the curing agent comprises: 50-60 wt % of isophorone diamine, 20-25 wt % of benzyl alcohol and 20-25 wt % of a second epoxy resin.

[0035] In the present invention, as a preferred embodiment, the curing agent is R-2269 curing agent produced by Rich New Materials (Guangzhou) Co., Ltd.

[0036] According to the present invention, preferably, the pore material is at least one of a disintegrant, a single crystal and sodium chloride.

[0037] According to the present invention, preferably, the particle size of the porous material is 1-3 mm.

[0038] According to the present invention, preferably, the disintegrant comprises an organic acid and a basic carbonate;

[0039] More preferably, the organic acid is citric acid.

[0040] More preferably, the basic carbonate is sodium bicarbonate.

[0041] In the present invention, as a preferred embodiment, the disintegrant is purchased from Guangzhou Meichuntang Pharmaceutical Technology Co., Ltd.

[0042] According to the present invention, preferably, the single crystal is a sucrose single crystal.

[0043] In the present invention, as a preferred embodiment, the sucrose single crystals are purchased from Jingshan Changfengpo Food Co., Ltd.

[0044] In the present invention, as a preferred embodiment, the sodium chloride is natural crystal sea salt produced in Bohai Sea, Shandong.

[0045] In the present invention, since the disintegrant includes an organic acid and a basic carbonate, the disintegrant can be rapidly melted and disintegrated upon contact with water and generate a large amount of carbon dioxide gas. The single crystal can also be soluble in water, with a solubility of 203.9 g at 20° C., and the solubility of sodium chloride in water is 36 g.

[0046] According to the present invention, preferably, before performing the step S3, it also includes applying a release coating on the inner surface of the mold, and placing the mold coated with the release coating in a dry and ventilated place for standby use.

[0047] In the present invention, as a preferred embodiment, the material of the release coating is vaseline.

[0048] According to the present invention, preferably, in step S5, the temperature of the drying treatment is 75 - 85 °C, and the time is 70 - 75 h.

[0049] In the present invention, as a preferred solution, the method for preparing the pore-type artificial core model of the present invention specifically includes the following steps:

[0050] 1. Mold pretreatment

[0051] After the mold is made, apply a layer of vaseline on the inner surface of the mold as a demolding coating, and place the treated mold in a dry and ventilated place for standby.

[0052] 2. Material mixing

[0053] Weigh quartz sand and cementing agent according to the above ratio, mix them evenly to obtain a cementing material.

[0054] 3. Particle grinding

[0055] Grind the pore material into small particles with a particle size of 1 - 3 mm.

[0056] 4. Artificial core preparation

[0057] Mix the pore material evenly into the cementing material to obtain a mixed material; then layer the mixed material into the mold, and finally place the mold under a fixed pressure for 24 hours until the quartz sand solidifies into rock.

[0058] 5. Curing and demolding

[0059] Take out the cured artificial core in the mold and polish the end face to obtain a cured artificial core.

[0060] 6. Particle precipitation

[0061] Immerse the cured artificial core in water to obtain a mixed system; perform a vacuum treatment on the mixed system to facilitate the rapid infiltration of water into the pores of the cured artificial core and promote the dissolution of the pore material in water.

[0062] 7. Core drying

[0063] After the pore material dissolves in water and precipitates, a pore-structured artificial core is obtained. Place this core in an 80 °C oven for 72 h to evaporate the water in the core and obtain the pore-type artificial core model.

[0064] The second aspect of the present invention provides the pore-type artificial core model prepared by the above method.

[0065] The third aspect of the present invention provides the application of the pore-type artificial core model in the forward modeling method research of pore-type reservoir seismic physical models.

[0066] The present invention is specifically described below by way of examples.

[0067] In the following embodiments:

[0068] The particle size of the quartz sand is 100 meshes and the origin is Hebei.

[0069] The binder comprises the following components by weight: 8 parts of a first epoxy resin and 4 parts of an R-2269 curing agent. The first epoxy resin is a bisphenol A type liquid epoxy resin with an epoxy equivalent of 184-195 g / mol and a viscosity of 10000-16000 mPas at 25°C.

[0070] The disintegrant includes citric acid and sodium bicarbonate, and the disintegrant is purchased from Guangzhou Meichuntang Pharmaceutical Technology Co., Ltd.

[0071] The single crystal is a sucrose single crystal, and the sucrose single crystal is purchased from Jingshan Changfengpo Food Co., Ltd.

[0072] The sodium chloride is made of natural crystal sea salt produced in Bohai Sea, Shandong.

[0073] Embodiment 1

[0074] This embodiment provides a method for preparing a hole-type artificial core model, such as Figure 1 As shown, the following steps are included:

[0075] 1. Mold pretreatment

[0076] After the mold is made, apply a layer of vaseline on the inner surface of the mold as a release coating, and place the treated mold in a dry and ventilated place for use.

[0077] 2. Material Mixing

[0078] The quartz sand and the binder are mixed evenly to obtain a binder material.

[0079] 3. Particle grinding

[0080] The disintegrant is ground into small particles with a particle size of 1-3 mm to obtain a porous material.

[0081] 4. Artificial Core Preparation

[0082] The porous material is evenly mixed into the cementing material to obtain a mixed material; the mixed material is then placed into a mold layer by layer, and finally the mold is placed under a fixed pressure and pressed for 24 hours to wait for the quartz sand to solidify into rock.

[0083] 5. Curing and demoulding

[0084] The artificial core solidified in the mold is taken out, and the end surface is polished to obtain a solidified artificial core.

[0085] 6. Particle precipitation

[0086] Immerse the solidified artificial core in water to obtain a mixed system; perform a vacuum treatment on the mixed system to facilitate the rapid penetration of water into the pores of the solidified artificial core and promote the dissolution of the pore-forming material in water.

[0087] 7. Core drying

[0088] After the pore-forming material is dissolved in water and precipitated, an artificial core with a pore structure is obtained. Place this core in an oven at 80 °C for 72 h to allow the water in the core to evaporate, obtaining the pore-type artificial core model.

[0089] In the above method, the dosage ratio of quartz sand, the first epoxy resin, the R-2269 curing agent, and the disintegrant is 100:8:4:10.

[0090] Example 2

[0091] This example provides a method for preparing a pore-type artificial core model, as Figure 1 shown, including the following steps:

[0092] 1. Mold pretreatment

[0093] After the mold is made, apply a layer of vaseline on the inner surface of the mold as a demoulding coating, and place the treated mold in a dry and ventilated place for standby.

[0094] 2. Material mixing

[0095] Mix quartz sand and the cementing agent evenly to obtain a cementing material.

[0096] 3. Particle grinding

[0097] Grind the single crystal into small particles with a particle size of 1-3 mm to obtain the pore-forming material.

[0098] 4. Artificial core preparation

[0099] Uniformly mix the pore-forming material into the cementing material to obtain a mixed material; then layer the mixed material into the mold, and finally place the mold under a fixed pressure for 24 hours until the quartz sand solidifies into rock.

[0100] 5. Curing and demoulding

[0101] Take out the solidified artificial core in the mold and polish the end face to obtain the solidified artificial core.

[0102] 6. Particle precipitation

[0103] Soak the solidified artificial core in water to obtain a mixed system; perform a vacuum treatment on the mixed system to facilitate the rapid penetration of water into the pores of the solidified artificial core and promote the dissolution of the pore-forming material in water.

[0104] 7. Core drying

[0105] After the pore-forming material dissolves in water and precipitates, an artificial core with a pore structure is obtained. Place this core in an oven at 80 °C for 72 h to allow the water in the core to evaporate, obtaining the pore-type artificial core model.

[0106] In the above method, the dosage ratio of quartz sand, the first epoxy resin, the R-2269 curing agent, and the single crystal is 100:8:4:10.

[0107] Example 3

[0108] This example provides a method for preparing a pore-type artificial core model, as Figure 1 shown, including the following steps:

[0109] 1. Mold pretreatment

[0110] After making the mold, apply a layer of petroleum jelly on the inner surface of the mold as a demoulding coating, and place the treated mold in a dry and ventilated place for standby.

[0111] 2. Material mixing

[0112] Mix quartz sand and the cementing agent evenly to obtain a cementing material.

[0113] 3. Particle grinding

[0114] Grind sodium chloride into small particles with a particle size of 1-3 mm to obtain the pore-forming material.

[0115] 4. Artificial core preparation

[0116] Uniformly mix the pore-forming material into the cementing material to obtain a mixed material; then layer the mixed material into the mold, and finally place the mold under a fixed pressure for 24 hours until the quartz sand solidifies into rock.

[0117] 5. Curing and demoulding

[0118] Take out the solidified artificial core in the mold and polish the end face to obtain the solidified artificial core.

[0119] 6. Particle precipitation

[0120] Soak the solidified artificial core in water to obtain a mixed system; perform a vacuum treatment on the mixed system to facilitate the rapid penetration of water into the pores of the solidified artificial core and promote the dissolution of the pore-forming material in water.

[0121] 7. Core drying

[0122] After the porous material is dissolved in water and precipitated, an artificial core with a porous structure is obtained. The core is placed in an oven at 80 °C for 72 h to allow the water in the core to evaporate, obtaining the porous artificial core model.

[0123] In the above method, the dosage ratio of quartz sand, the first epoxy resin, the R-2269 curing agent and sodium chloride is 100:8:4:10.

[0124] From the process observation of the preparation methods of Examples 1, 2, and 3, it can be seen that the porous materials used in Examples 1, 2, and 3 can all be dissolved in water, so that a porous structure is left in the artificial core. See Table 1 for details.

[0125] Table 1

[0126] Serial number Particulate matter Experimental result Example 1 Disintegrant The pore-forming material dissolves in water, leaving a pore structure in the artificial core Example 2 Single crystal The pore-forming material dissolves in water, leaving a pore structure in the artificial core Example 3 Sodium chloride The pore-forming material dissolves in water, leaving a pore structure in the artificial core

[0127] Example 4

[0128] This example provides a method for preparing a porous artificial core model. The difference between this example and Example 3 is only that:

[0129] The dosage ratio of quartz sand, the first epoxy resin, the R-2269 curing agent and sodium chloride is 100:8:4:12.

[0130] Example 5

[0131] This example provides a method for preparing a porous artificial core model. The difference between this example and Example 3 is only that:

[0132] The dosage ratio of quartz sand, the first epoxy resin, the R-2269 curing agent and sodium chloride is 100:8:4:14.

[0133] Test Example

[0134] This test example performs CT scans on the porous artificial core models prepared in Examples 1, 2, and 3, and respectively obtains the CT scan slices of the porous artificial core models in Examples 1, 2, and 3. As Figures 2-4 shown, it can be seen that: Figures 2-4 The black dots in are the porous structures left in the core after the porous material precipitates. The three porous materials in Examples 1, 2, and 3 can all leave porous structures in the core. However, among these three materials, there will be a little sodium thiosulfate solid residue after the disintegrant undergoes a disintegration reaction in water; the viscosity of the single crystal aqueous solution is relatively large, and it is more difficult to precipitate from the core compared with the other two materials; while the viscosity of the sodium chloride aqueous solution is moderate, it is easy to precipitate and there is no solid residue, which is the first choice among the three porous materials.

[0135] This test example also conducts acoustic wave propagation velocity tests on the porous artificial core models prepared in Examples 1, 2, 3, 4, and 5. The results are shown in Table 1. The porous artificial cores prepared after the precipitation of the three porous materials have larger amplitude values, good acoustic wave penetrability, and smaller errors in multiple measurement values, with stable wave velocities. In addition, by comparing the test results of Examples 3, 4, and 5, it can be seen that the more the amount of porous material used, that is, the more porous structures in the core, the smaller the wave velocity of the core and the worse the acoustic wave penetrability.

[0136] Table 1

[0137]

[0138]

[0139] The various embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments.

Claims

1. A method for preparing a porous artificial core model, characterized in that, the method comprises the following steps: S1: Mix quartz sand and a cementing agent evenly to obtain a cementing material; S2: Mix a pore material with the cementing material evenly to obtain a mixed material; S3: Inject the mixed material into a mold, and successively perform pressing, curing, demolding and polishing to obtain a solidified artificial core; S4: Mix the solidified artificial core with water to obtain a mixed system; perform a vacuum treatment on the mixed system to allow water to penetrate into the solidified artificial core to obtain a porous artificial core; S5: Perform a drying treatment on the porous artificial core to obtain the porous artificial core model.

2. The method according to claim 1, wherein, the dosage ratio of the quartz sand, the cementing agent and the pore material is (80 - 120):(2 - 20):(9 - 15).

3. The method according to claim 1 or 2, wherein, the particle size of the quartz sand is 60 - 140 mesh; the cementing agent comprises the following components in parts by weight: 6 - 10 parts of a first epoxy resin and 2 - 6 parts of a curing agent; the pore material is at least one of a disintegrant, a single crystal and sodium chloride; the particle size of the pore material is 1 - 3 mm.

4. The method according to claim 3, wherein, the first epoxy resin is a bisphenol A liquid epoxy resin with an epoxy equivalent of 184 - 195 g / mol and a viscosity of 10000 - 16000 mPas at 25°C; based on the total weight of the curing agent, the curing agent comprises: 50 - 60 wt% of isophorone diamine, 20 - 25 wt% of benzyl alcohol and 20 - 25 wt% of a second epoxy resin.

5. The method according to claim 3, wherein, the disintegrant comprises an organic acid and a basic carbonate; preferably, the organic acid is citric acid; preferably, the basic carbonate is sodium bicarbonate.

6. The method according to claim 3, wherein, the single crystal is a sucrose single crystal.

7. The method according to claim 1, wherein, before performing the step S3, it further includes applying a demolding coating on the inner surface of the mold.

8. The method according to claim 1, wherein, in step S5, the temperature of the drying treatment is 75 - 85°C and the time is 70 - 75 h.

9. A porous artificial core model prepared by the method according to any one of claims 1 - 8.

10. Application of the porous artificial core model according to claim 9 in the forward modeling method research of a porous reservoir seismic physical model.

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