Preparation method of visual core acidizing corrosion measurement model

Abstract

The present invention belongs to the technical field of oilfield development, and in particular, is a method for preparing a visualized core acidification corrosion measurement model. The technical scheme of the present invention is: select the required measurement core, and obtain two core models with the same thickness of 2-4 mm according to the design; evenly apply the prepared adhesive on both sides of the two core slices, and then bond them with two pieces of white glass with the same specifications; the two core slices are arranged oppositely, and two sections of hoses are clamped and arranged at both ends of the core slices; finally, the outer periphery of the core slice between the two pieces of glass is evenly coated with adhesive, and statically consolidated to obtain a visualized core acidification corrosion measurement model. The present invention utilizes the visibility of glass and the authenticity of the properties of the required acidified formation core, and the two are combined to highly restore the formation acidification process, so that the evaluation process is more real and visible, and the problems generated in the acidification process can be intuitively analyzed. At the same time, the present invention is simple to make, low in cost, and short in testing time, and has high practicality.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield development, and in particular to a method for preparing a visualized core acidizing corrosion measurement model. Background Art

[0002] Acidizing refers to the use of acid or potential acid to treat oil and gas reservoirs to restore or increase the permeability of oil and gas layers and achieve a technical means of increasing the production of oil and gas wells. The specific operation is to pump acid into the formation to be treated to obtain high conductivity fracture acidizing. However, the current acidizing evaluation of cores is basically to evaluate the performance of the acid through core displacement experiments. This has the problem that the acidizing evaluation process is not visible, and during the core displacement process, the acid fingering caused by the heterogeneity of the core will affect the acidizing effect. Since it is impossible to analyze the phenomenon of acid during the acidizing flow process, it is difficult to restore the formation acidizing process, making the evaluation process not true enough and unable to achieve the purpose of guiding the increase in oil and gas well production. Summary of the invention

[0003] In order to solve the problems in the prior art that the core corrosion test process is invisible, it is difficult to restore the formation acidification process, the evaluation process is not realistic enough, and it cannot effectively guide the increase in oil and gas well production, a method for preparing a visual core acidification corrosion measurement model is provided.

[0004] To achieve the above object, the present invention adopts the following technical solution: a method for preparing a model for visualizing core acidizing corrosion measurement, comprising the following steps:

[0005] 1) Select the required core for measurement, and use the wire cutting rock sampler to linearly cut the core according to the designed holes to obtain two core slices with the same thickness of 2-4 mm, with an error of no more than 0.001 mm.

[0006] 2) Prepare adhesive;

[0007] 3) evenly coating both sides of the two core slices with the prepared adhesive to obtain two double-sided coated core slices;

[0008] 4) One plane of the two core slices is bonded to two pieces of white glass with the same specifications;

[0009] 5) Two core slices are arranged opposite to each other, and two hoses are clamped at both ends of the core slices;

[0010] 6) The adhesive is evenly coated on the periphery of the core slice between the two pieces of glass, and the core slice is left to stand until the adhesive is completely solidified, thereby obtaining a visual core acidification corrosion measurement model.

[0011] In step 6), the consolidation temperature is 25 to 30° C. and the time is 12 to 24 hours.

[0012] In step 2), the adhesive is AB type Dongfeng all-purpose adhesive, the configuration mass ratio is 1:1, and the adhesive is prepared and used immediately.

[0013] In step 4), the hose is made of PP, PTFE or PE acid-resistant material.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1. The present invention organically combines glass and core, utilizes the visibility of glass and the authenticity of the properties of the required acidified formation core, combines the two, highly restores the formation acidification process, and makes the evaluation process more real and visible, so that we can more intuitively analyze the problems arising in the acidification process during the evaluation process, and can effectively guarantee the authenticity of the reproduction of the acidified formation core properties, making the evaluation process more real.

[0016] 2. The holes in the core can be designed according to the actual holes in the formation. The real-time acidizing contact area during the test can be calculated after observation, and the phenomenon of acid in the acidizing flow process can be analyzed in real time.

[0017] 3. The method of the present invention is simple, low-cost, short testing time, simple and ingenious principle, simple structure, easy manufacturing, good sealing under specific curing conditions, and acid is not easy to leak out.

[0018] 4. The required core material is small during the evaluation process, and multiple evaluations can be performed even when there is only limited core material. It is very practical and reduces the experimental cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Design diagram for the hole model based on the visual core acid corrosion measurement model;

[0020] Figure 2 This is a CAD diagram of the hole model based on the visual core acid corrosion measurement model;

[0021] Figure 3 The physical image of the required hole core based on the visual core acid corrosion measurement model;

[0022] Figure 4 It is a schematic diagram of the structure of the core acid corrosion measurement model based on visualization;

[0023] Figure 5 This is a physical picture of the visual core acidizing corrosion measurement model in Example 4;

[0024] Figure 6 A physical picture of the visual core acidizing corrosion measurement model in Example 1-7;

[0025] Figure 7 The acidizing process of the visualized core acidizing corrosion measurement model in Example 1; DETAILED DESCRIPTION

[0026] See also Figure 1-Figure 2 The present invention provides a method for preparing a model for visualizing core acidizing corrosion measurement, comprising the following steps:

[0027] 1) Select the required core for measurement, perform linear cutting on the core, and obtain two core slices with the required pore shape. The slice thickness is 2-4 mm. The thickness of the same slice must be consistent, and the error does not exceed 0.001 mm;

[0028] 2) Prepare the adhesive. The adhesive is AB type Dongfeng all-purpose adhesive. The configuration mass ratio is 1:1. The adhesive must be prepared and used immediately;

[0029] 3) evenly coating both sides of the two core slices with the prepared adhesive to obtain two double-sided coated core slices;

[0030] 4) One plane of the two core slices is bonded to two pieces of white glass with the same specifications;

[0031] 5) Two core slices are set to overlap relative to each other, and two pieces of glass are also completely overlapped. Two sections of hose are clamped and set at both ends of the core slice. The hose material is PP;

[0032] 6) The adhesive is evenly coated on the periphery of the core slice between the two pieces of glass, and the core slice is left to stand at a consolidation temperature of 25 to 30° C. for 12 to 24 hours. When the adhesive is completely solidified, a visualized core acidification corrosion measurement model is obtained.

[0033] The main storage space of the reservoir is fractures and caves. In order to study the reaction process between acid and rocks with pores and fractures, physical simulation of acid corrosion and expansion of fractures and caves was carried out. Therefore, a fracture + cave model design scheme was designed for this core slice, see Figure 3 Based on the design plan, the design drawing is digitized, and the CAD drawing of the designed fracture + cave model is drawn, and then the model is processed by a wire cutting rock sampler.

[0034] The present invention will be further described below with reference to specific embodiments and accompanying drawings:

[0035] Example 1: A method for preparing a model for visualizing core acidification corrosion measurement, comprising the following steps:

[0036] 1) Select the acid-corroded core to be measured, perform linear cutting on the core, and obtain two core slices with the required pore shape. The slice thickness is 2 mm, and the slice thickness is consistent, with an error of no more than 0.001 mm;

[0037] 2) Prepare the adhesive. The adhesive is AB type Dongfeng all-purpose adhesive. The configuration mass ratio is 1:1. The adhesive must be prepared and used immediately;

[0038] 3) evenly coating both sides of the two core slices with the prepared adhesive to obtain two double-sided coated core slices;

[0039] 4) One plane of the two core slices is bonded to two pieces of white glass with the same specifications;

[0040] 5) Two core slices are set opposite to each other, and the two pieces of glass are completely overlapped. Two sections of hose are clamped and set at both ends of the core slice. The hose material is PP;

[0041] 6) The adhesive is evenly coated on the periphery of the core slice between the two pieces of glass, and the core slice is left to stand at a consolidation temperature of 25° C. for 24 hours. When the adhesive is completely solidified, a visual core acidification corrosion measurement model is obtained.

[0042] Example 2: A method for preparing a model for visualizing core acidification corrosion measurement

[0043] The difference from Example 1 is that two core models with the required pore shape are used, and the slice thickness is 4 mm; the hose material used is PE; the consolidation temperature is 30°C, the time is 12 hours, and the visualized core acidification corrosion measurement model is obtained after the binder is completely solidified.

[0044] Example 3, a method for preparing a model for visualizing core acidification corrosion measurement

[0045] The difference from Example 1 is that two core models with the desired pore shape are used, and the slice thickness is 3 mm; the hose material used is PTFE; the consolidation temperature is 28°C, the time is 16 hours, and when the binder is completely solidified, a visual core acidification corrosion measurement model is obtained.

[0046] Example 4: A method for preparing a model for visualizing core acidification corrosion measurement

[0047] The difference from Example 1 is that two core models with the desired pore shape are used, and the slice thickness is 3 mm; the consolidation temperature is 25° C., and the time is 24 h. When the binder is completely solidified, a visualized core acidification corrosion measurement model is obtained.

[0048] Example 5: A method for preparing a model for visualizing core acidification corrosion measurement

[0049] The difference from Example 1 is that two core models with the desired pore shape are used, and the slice thickness is 3 mm; the consolidation temperature is 30° C., the time is 16 h, and when the binder is completely solidified, a visualized core acidification corrosion measurement model is obtained.

[0050] Example 6: A method for preparing a model for visualizing core acidification corrosion measurement

[0051] The difference from Example 1 is that two core models with the desired pore shape are used, and the slice thickness is 2 mm; the consolidation temperature is 26° C., and the time is 20 h. When the binder is completely solidified, a visualized core acidification corrosion measurement model is obtained.

[0052] Example 7, a method for preparing a model for visualizing core acidification corrosion measurement

[0053] The difference from Example 1 is that two core models with the desired pore shape are used, and the slice thickness is 2 mm; the consolidation temperature is 27° C., the time is 19 h, and when the binder is completely solidified, a visualized core acidification corrosion measurement model is obtained.

[0054] See also Figure 5 and Figure 6 , it can be seen that the holes of all the prepared models are completely visible, making the evaluation process more realistic and visual.

[0055] Use a pressure pump to inject acid into the model at a rate of 1 mL / min, and the acidification phenomenon can be observed in real time and the acidification rate can be calculated. The acidification contact area can be calculated in real time, and visualization allows us to more intuitively analyze the problems that arise during the acidification process during the evaluation process, see Figure 7 .

[0056] The above content is a further detailed description of the present invention. It cannot be determined that the specific implementation methods of the present invention are limited to these. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, they can also make several simple deductions or substitutions, which should be regarded as belonging to the protection scope of the present invention determined by the submitted claims.

Claims

1. A method for preparing a model for visualizing core acidification corrosion measurement, comprising the following steps: 1) Select the required measurement core, and use the wire cutting rock sampler to linearly cut the core according to the designed holes to obtain two core slices with the same thickness of 2-4 mm, with an error of no more than 0.001 mm. The core slices are designed with a fracture + cave model; 2) Prepare adhesive; 3) Evenly coating the prepared adhesive on both sides of the two core slices to obtain two double-sided coated core slices; 4) One plane of the 2 core slices is bonded to two pieces of white glass with the same specifications; 5) Two core slices are arranged opposite to each other, and there are two openings between the two core slices; two hoses are clamped and arranged at both ends of the core slices, and are respectively located in the two openings between the two core slices; 6) The adhesive is evenly coated on the periphery of the core slice between the two pieces of glass, and the mixture is allowed to stand until the adhesive is completely solidified, thereby obtaining a visual core acidification corrosion measurement model; in step 6), the solidification temperature is 25-30 °C, and the time is 12-24 h.

2. The method for preparing a model for visual core acidification corrosion measurement according to claim 1, characterized in that: In step 2), the adhesive is AB type Dongfeng all-purpose adhesive, the configuration mass ratio is 1:1, and the adhesive is prepared and used immediately.

3. The method for preparing a model for visualizing core acidizing corrosion measurement according to claim 1, characterized in that: In step 4), the hose is made of PP, PTFE or PE acid-resistant material.

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