Film-coated proppant consolidation body manufacturing mold and manufacturing method

Abstract

The invention discloses a film-coated proppant consolidation body manufacturing mold and a manufacturing method. The manufacturing die comprises a female die cylinder, the bottom of the female die cylinder is connected with a bottom cap, and a male die is inserted into the female die cylinder. The manufacturing method comprises the following steps: weighing the film-coated proppant, adding a working solution which is required to be prepared, completely immersing the film-coated proppant in the working solution, and enabling the liquid level to be at least 20mm higher than the film-coated proppant; fully stirring until the surface of the film-coated proppant is completely wet, transferring the film-coated proppant and the working solution into a consolidation body manufacturing mold, inserting a positive film pressing rod into the mold, pressurizing to 3-8kN by using rock mechanics test equipment, and continuing for 30-60s; the consolidation body manufacturing mold is vertically placed in a water bath to be subjected to constant-temperature curing for 24 h or above, and the curing temperature is the formation temperature; and removing a bottom cap of the mold, and taking out the rock core by using rock mechanics test equipment by replacing the pressure rod to obtain a consolidated body. The consolidation body parallel sample manufactured by the method has no difference in performance, and the accuracy and the reliability of a final measurement result can be guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of oil development tests, and particularly to a mold and a manufacturing method for a consolidated body of a coated proppant. Background Art

[0002] In the field of oil development, a coated proppant is also called an oil fracturing proppant. When deep wells of oil and natural gas are exploited, after a high-closure-pressure and low-permeability deposit is fractured, the oil and gas-bearing rock formation is cracked, and the oil and gas converge from the channels formed by the cracks. At this time, it is necessary to inject fluid into the rock base layer with a pressure exceeding the formation fracture strength to generate cracks in the rock formation around the wellbore, forming a channel with high laminar flow capacity. To keep the cracks formed after fracturing open and enable the oil and gas products to pass through smoothly, the performance of the coated proppant plays a key role in the fracturing effect.

[0003] To evaluate the performance of a coated proppant, it is necessary to fabricate a consolidated body to test parameters such as permeability and compressive strength. Currently, there are mainly two types of molds for fabricating consolidated bodies: glass tubes and steel tubes. For a glass tube, after the proppant is solidified inside the glass tube, the glass tube is broken to take out the consolidated body. During the process of breaking the glass tube, on the one hand, it is easy to damage the consolidated body, which will affect the test results of the performance of the consolidated body. On the other hand, the glass tube is disposable and costly. In addition, during the process of breaking the glass tube, the splashing glass poses a great safety hazard. For a steel tube, it can be reused and there is no safety hazard. Usually, the consolidated body is pushed out from one end of the steel tube. However, this kind of mold for fabricating a consolidated body is only suitable for fabricating a consolidated body of a coated proppant in a water-free environment. Some coated proppants on the market need to dissolve the curing agent in water and can only be consolidated under the promotion of the curing agent. The existing steel tube models (mold segments) do not have a sealing function, so such coated proppants cannot fabricate a consolidated body. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a mold and a manufacturing method for a consolidated body of a coated proppant.

[0005] In a first aspect, the present invention provides a mold for fabricating a consolidated body of a coated proppant, which is achieved by the following technical solutions.

[0006] A mold for fabricating a consolidated body of a coated proppant, characterized in that: it includes a female mold cylinder, the bottom of the female mold cylinder is connected to a bottom cap, and a male mold is inserted into the female mold cylinder.

[0007] Further, the female mold cylinder is threadedly connected to the bottom cap.

[0008] Further, a groove is formed on the outer wall of the bottom of the female mold cylinder, and a sealing ring is embedded in the groove.

[0009] Further, the sealing ring is an O-ring.

[0010] Further, the outer diameter of the male mold matches the inner diameter of the female mold cylinder.

[0011] In a second aspect, the present invention provides a method for manufacturing a coated proppant consolidated body, which is achieved by the following technical solutions.

[0012] A method for manufacturing a coated proppant consolidated body, the coated proppant consolidated body is manufactured using the above-mentioned manufacturing mold, and includes the following steps:

[0013] S1: According to the density of the coated proppant, weigh the amount of coated proppant required for a 25×25 mm standard core, add the required working fluid to be prepared, and the working fluid completely submerges the coated proppant, and the liquid level is at least 20 mm higher than the coated proppant;

[0014] S2: Stir well until the surface of the coated proppant is completely wetted, transfer it to the consolidated body manufacturing mold together with the working fluid, insert the male mold pressing rod into the mold, and apply pressure with a rock mechanics test equipment to 3 - 8 kN and maintain it for 30 - 60 s;

[0015] S3: Vertically place the consolidated body manufacturing mold in a water bath for constant temperature curing for more than 24 h, and the curing temperature is the formation temperature;

[0016] S4: Remove the bottom cap of the mold, and use a rock mechanics test equipment to take out the core through the displacement pressing rod to obtain a consolidated body with a diameter of 25 mm ± 0.5 mm and a length of 25 mm ± 1 mm.

[0017] This application has the following beneficial effects.

[0018] (1) The overall structure of the present invention is designed simply and reasonably, easy to operate, and the properties of the parallel samples of the manufactured consolidated body have no differences, which can ensure the accuracy and reliability of the final measurement results, and is conducive to following rules in solving technical problems;

[0019] (2) The present invention overcomes the defects of glass tube molds, steel pipe models (mold segments), etc., and is applicable to the manufacture of all types of coated proppant consolidated bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of the present invention.

[0021] Among them, 1, female mold cylinder; 2, sealing ring; 3, bottom cap; 4, male mold. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following further describes this patent application in conjunction with embodiments.

[0023] Such as Figure 1As shown in the figure, a production mold for a coated proppant consolidated body includes a female mold cylinder 1, a sealing ring 2, a bottom cap 3 and a male mold 4.

[0024] The female mold cylinder 1 has a cylindrical structure, with an external thread provided on the outer wall of the lower part and a groove for placing the sealing ring 2 on the outer wall of the bottom. The sealing ring 2 is an O-ring. The inner wall of the female mold cylinder 1 is smooth and free of burrs, with an inner diameter of 25 mm and an outer diameter of 35 mm.

[0025] The inner wall of the bottom cap 3 is provided with an internal thread, which cooperates with the external thread on the female mold cylinder 1 to achieve the threaded connection between the female mold cylinder 1 and the bottom cap 3. The two are sealed by the sealing ring 2 to prevent liquid from flowing out. The inner diameter of the bottom cap 3 is 35 mm, the outer diameter is 43 mm, and the outer wall is provided with a strip-shaped groove for easy disassembly.

[0026] A solid male mold 4 is provided inside the female mold cylinder 1. The outer diameter of the male mold 4 matches the inner diameter of the female mold cylinder 1. The male mold 4 is placed inside the mold cylinder 1 and is used to compact and flatten the end face of the coated proppant consolidated body. The diameter of the male mold 4 is 24.5 mm.

[0027] In this application, the female mold cylinder 1, the bottom cap 3 and the male mold 4 are made of stainless steel material, which can withstand a certain pressure, is not easy to deform and is durable;

[0028] Using the above production mold for a coated proppant consolidated body, the method for producing a coated proppant consolidated body is carried out according to the following steps:

[0029] Step 1: Weigh a certain amount of coated proppant and put it into a beaker, add the working fluid prepared as required. The working fluid should completely submerge the coated proppant, and the liquid level should be at least 20 mm higher than the coated proppant;

[0030] Step 2: Use a glass rod to stir thoroughly until the surface of the coated proppant is completely wetted, then transfer it together with the working fluid to the consolidated body production mold. Insert the male mold pressing rod into the mold, and use a rock mechanics test equipment (similar instrument) to apply pressure up to 5 kN and maintain it for 30 s;

[0031] Step 3: Place the consolidated body production mold vertically in a water bath for constant temperature curing for 24 h, and the curing temperature is the formation temperature;

[0032] Step 4: Remove the bottom cap of the mold, and use a rock mechanics test equipment (similar instrument) to take out the core through the displacement pressing rod to obtain a consolidated body with a specification of diameter 25 mm ± 0.5 mm (measured with a vernier caliper) and length 25 mm ± 1 mm (measured with a vernier caliper).

[0033] Example

[0034] A method for producing a coated proppant consolidated body includes the following steps:

[0035] a) Prepare 20 mL of working fluid by mixing 10% phenolic epoxy resin + 3% phenolic amine curing agent + 1% polysulfonamide fiber, and set it aside after mixing evenly.

[0036] b) Weigh 20 g of coated proppant with a bulk density of 1.8 g / cm 3 and put it into a beaker, then add 15 mL of working fluid. The working fluid should completely submerge the coated proppant, and the liquid level should be at least 20 mm higher than the coated proppant.

[0037] c) Assemble the female mold cylinder with the sealing ring and bottom cap.

[0038] d) Continuously transfer the well-stirred coated proppant, which is completely wetted on the surface, together with the working fluid into the female mold cylinder for making the consolidated body.

[0039] e) Insert the male mold pressing rod into the mold for making the consolidated body, and compact it with a universal testing machine. Set the pressing conditions as 5 kN and 30 s.

[0040] f) Place the mold for making the consolidated body in a water bath at 60 °C and cure it at a constant temperature for 24 h.

[0041] g) Demolding process: After curing, unscrew the bottom cap, and under the action of the universal testing machine, eject the consolidated body from one end of the mold, thus completing the demolding operation.

[0042] h) Measure the aqueous phase permeability and compressive strength of the made coated proppant consolidated body according to SY / T5345 - 2007 and GB / T 50289 - 2019.

[0043] Table 1 Performance parameters of the consolidated body made by the present invention

[0044] Test Items Duplicate Sample 1 Duplicate Sample 2 Duplicate Sample 3 Duplicate Sample 4 Duplicate Sample 5 Length, cm 2.525 2.525 2.525 2.525 2.527 Diameter, cm 2.474 2.474 2.474 2.474 2.474 Aqueous Phase Permeability, D 7.35 7.43 7.30 7.28 7.22 Compressive Strength, MPa 9.4 9.4 9.8 9.8 9.8

[0045] As can be seen from Table 1, the mold for making the consolidated body of the present invention can more effectively simulate the formation, and the coated proppant consolidates in the water environment; the demolding success rate is greatly improved, basically remaining at 100%, and the properties of the parallel samples of the made consolidated body have no difference, which can ensure the accuracy and reliability of the final measurement results and is conducive to following rules in solving technical problems.

[0046] The embodiments of this specific implementation manner are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A mold for making a film-coated proppant consolidation body, characterized in that: The invention comprises a female mold cylinder (1), the bottom of which is connected to a bottom cap (3), and a male mold (4) is inserted into the female mold cylinder (1).

2. A mold for making a film-coated proppant consolidation body according to claim 1, characterized in that: The female mold cylinder (1) is threadedly connected to the bottom cap (3).

3. A mold for making a film-coated proppant consolidation body according to claim 1, characterized in that: A groove is formed on the outer wall of the bottom of the female mold cylinder (1), and a sealing ring (2) is embedded in the groove.

4. A mold for making a film-coated proppant consolidation body according to claim 3, characterized in that: The sealing ring (2) is an O-shaped sealing ring.

5. The mold for making a film-coated proppant consolidation body according to claim 1, characterized in that: The outer diameter of the male mold (4) matches the inner diameter of the female mold cylinder (1).

6. A method for preparing a film-coated proppant consolidation body, characterized in that: The coated proppant consolidation body is manufactured by using the manufacturing mold described in any one of claims 1 to 5. The following steps are involved: S1: According to the density of the coated proppant, weigh the amount of coated proppant required for a 25×25mm standard core, add the required working fluid, and completely immerse the coated proppant in the working fluid, with the liquid level at least 20mm higher than the coated proppant; S2: Stir thoroughly until the surface of the coated proppant is completely wetted, and transfer it together with the working fluid into the consolidation body production mold, insert the positive film pressure rod into the mold, and use the rock mechanics test equipment to pressurize to 3-8kN and keep it for 30-60s; S3: vertically place the mold for making the consolidation body in a water bath for constant temperature curing for more than 24 hours, and the curing temperature is the formation temperature; S4: Remove the bottom cap of the mold, use rock mechanics testing equipment to remove the core by replacing the pressure rod, and obtain a consolidated body with a diameter of 25mm±0.5mm and a length of 25mm±1mm.

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