Interface enhancer and construction method thereof

Abstract

The invention discloses an interface enhancer and a construction method thereof. The interface enhancer comprises water-based latex, emulsified asphalt, an enhancer, modified nickel slag powder, a magnesium-based stabilizer, a superfine siliceous material and a dispersing agent. The magnesium-based stabilizer is sodium oleate modified magnesium oxide and magnesium borate whisker. The construction method comprises the following steps: uniformly mixing the water-based latex and the emulsified asphalt to obtain a mixed emulsion A; mixing a reinforcing agent with a dispersing agent to obtain a reinforced pre-reaction solution B, and adding the modified nickel slag powder, a superfine siliceous material and a magnesium-based stabilizer to form a reaction reinforced solution C; and finally, uniformly stirring the mixed emulsion A and the reaction strengthening liquid C, coating the well wall with the mixed emulsion A and the reaction strengthening liquid C, and reacting to form a consolidated body. The material system of the interface enhancer is high in compressive strength and excellent in toughness, and when the interface enhancer is applied to the well wall, the compressive strength of the well wall can be effectively improved.

Description

Technical Field

[0001] This invention relates to the technical field of an interface strengthening agent and its application method. Background Technology

[0002] In the field of oil and gas drilling and extraction technology, the geological structures are complex and the rock distribution is often uneven. Instability and leakage can occur in some areas, which adversely affect drilling and extraction operations, seriously impacting the work and requiring a significant investment of manpower and time for plugging and repairing leaks. Therefore, it is essential to find effective solutions to plug leaks in lost circulation zones.

[0003] Currently, commonly used plugging technologies include: mechanical filling plugging, chemical reaction plugging, hydration gelling plugging, expansion plugging, and bridging plugging. Since oil and gas wells are often located at very deep depths and have complex geological, hydrological, and temperature conditions, and the interface of the leak zone is in a humid, hot, acidic, or alkaline environment, ordinary interface strengthening agents often have poor performance such as low toughness or cracking. They may be damaged and fail during the process of strengthening the unstable rock layer at the mine interface.

[0004] Based on this, we are now studying a new type of oil and gas drilling method using interface strengthening agents and their construction methods, which can simultaneously possess excellent compressive strength and toughness, thereby improving the compressive strength of the wellbore. Summary of the Invention

[0005] Purpose of the invention: The technical problem to be solved by the present invention is to provide an interface strengthening agent for oil and gas drilling and its construction method. The interface strengthening agent has excellent compressive strength and toughness, and can improve the compressive strength of the coated well wall, thereby effectively plugging leakage points.

[0006] Technical solution: The interface strengthening agent of the present invention comprises the following raw materials by weight: 30-50 parts of water-based latex, 20-30 parts of emulsified asphalt, 10-20 parts of reinforcing agent, 8-15 parts of modified nickel slag powder, 2-8 parts of magnesium-based stabilizer, 1-5 parts of ultrafine silica material and 5-10 parts of dispersant; wherein the magnesium-based stabilizer is a composite whisker of sodium oleate modified magnesium oxide and magnesium borate in a weight fraction ratio of (1-3):1.

[0007] This invention utilizes a synergistic interface strengthening material system based on water-based latex, emulsified asphalt, ultrafine silica materials, reinforcing agents, and dispersants, combined with modified nickel slag powder and magnesium-based stabilizers. This interface strengthening agent not only possesses excellent compressive strength and toughness within the system itself, but also, when coated onto the well wall, effectively enhances the compressive strength of the well wall, achieving effective leak sealing. Specifically, the use and modification of nickel slag promotes interfacial bonding between the nickel slag and emulsified asphalt and water-based latex, improving the interface's resistance to cracking and water damage. A magnesium-based stabilizer composed of sodium oleate-modified magnesium oxide powder and magnesium borate whiskers is used. On the one hand, magnesium oxide powder has a micro-expansion effect, which can improve the filling density of leakage points. On the other hand, the modification of magnesium oxide powder with sodium oleate improves the selectivity of magnesium oxide reaction with siliceous materials and wellbore materials in the system, reduces non-specific reactions with other components, and enables targeted reactions with siliceous materials in the system and acidic rocks, acidic sands and siliceous materials in the wellbore, to produce silicate phases with cementing strength, which improves the strength of the phase itself and the bonding strength with the wellbore. Meanwhile, magnesium borate whiskers can effectively transfer and disperse stress, and enhance the toughness of the interface strengthening agent system. In other words, the use of magnesium oxide powder and magnesium borate whiskers as a composite interface strengthening agent can enhance the strength and toughness of the solidified body after reaction while ensuring volume stability.

[0008] Furthermore, the water-based latex used in this interface strengthening agent can be selected from one or more of acrylic emulsions, styrene-acrylic emulsions, and epoxy acrylic emulsions.

[0009] Furthermore, the reinforcing agent used in this interface strengthening agent can be selected from one or more of dimethacrylate, methyl urethane, or benzyl urethane.

[0010] Furthermore, the modified nickel slag powder used in this interface strengthening agent is prepared by the following steps: after grinding the nickel slag powder, 10-20% of ammonium sulfate solution (by weight of the nickel slag powder) is added and modified at 60-80 ℃ for 3-4 h, then 1%-3% of stearic acid (by weight of the nickel slag powder) is added, and finally, surface activity treatment is carried out by stirring at 80-100 ℃ for 30-60 min.

[0011] Furthermore, the ultrafine siliceous material used in this interface strengthening agent can be selected from one or more of silica fume, fly ash, and silica powder, with a fineness of 300 mesh or more.

[0012] Furthermore, the dispersant used in this interface strengthening agent can be selected from one or more of propylene carbonate, ethylene carbonate, and ethyl methyl carbonate.

[0013] Furthermore, the sodium oleate-modified magnesium oxide used in this interface strengthening agent is prepared by the following steps: first, 2-5% of sodium oleate by mass of magnesium oxide powder is dissolved in ethanol to obtain a sodium oleate dispersion, then magnesium oxide powder is added, and the mixture is mechanically stirred for 10-15 min at a speed of 500-1000 r / min, and then ultrasonically dispersed for 10-20 min to obtain a sodium oleate-modified magnesium oxide slurry with a concentration of 5-10 wt%.

[0014] The application method of the interface strengthening agent of the present invention includes the following steps:

[0015] (1) Mix water-based latex and emulsified asphalt evenly to obtain mixed emulsion A;

[0016] (2) The reinforcing agent and the dispersant are mixed to obtain the enhanced pre-reaction liquid B, and modified nickel slag powder, ultrafine silicon material and magnesium-based stabilizer are added to form the reaction enhancement liquid C;

[0017] (3) Finally, mix the mixed emulsion A and the reaction strengthening liquid C evenly, apply it to the well wall, and form a solid body after the reaction.

[0018] Beneficial effects: Compared with the prior art, the significant advantages of the present invention are: the interface strengthening agent not only has high compressive strength (greater than 21 MPa) and excellent toughness (tensile strength greater than 18 MPa and elongation at break greater than 370%), but also, when coated on well wall materials, it has strong bonding ability with well wall materials, which can effectively improve the compressive strength of well wall materials and effectively plug leaks. Detailed Implementation

[0019] The technical solution of the present invention will be further described in detail below with reference to the embodiments.

[0020] It should be noted that all raw materials used in this invention are commercially available. Specifically, the emulsified asphalt used can be selected from one or more of ordinary emulsified asphalt, SBS-modified emulsified asphalt, or SBR-modified emulsified asphalt, all of which are well-known raw materials in the art.

[0021] The modified nickel slag powder used in the following embodiments of the present invention is prepared by the following steps: grinding the nickel slag powder to a fineness of 400 mesh or higher, adding 10-20% of the mass of the nickel slag powder in an ammonium sulfate solution with a concentration of 0.1-0.2 mol / L, modifying it at 60-80 ℃ for 3-4 h, then adding 1%-3% of the mass of the nickel slag powder in stearic acid, and finally stirring at 80-100 ℃ for 30-60 min for surface activation treatment.

[0022] The sodium oleate-modified magnesium oxide used in the following embodiments of the present invention is prepared by the following steps: first, sodium oleate accounting for 2-5% of the mass of magnesium oxide powder is dissolved in ethanol to obtain a sodium oleate dispersion, then magnesium oxide powder is added, and the mixture is mechanically stirred for 10-15 min at a speed of 500-1000 r / min, and then ultrasonically dispersed for 10-20 min to obtain a sodium oleate-modified magnesium oxide slurry with a concentration of 5-10 wt%.

[0023] Example 1

[0024] The composition of the interface strengthening agent in Example 1 is shown in Table 1 below.

[0025] Table 1. Interface strengthening agent of Example 1

[0026] Serial Number raw material Content / serving 1 acrylic emulsion 40 2 Emulsified asphalt 25 3 dimethacrylate 15 4 Modified nickel slag powder 12 5 Magnesium-based stabilizer (composite whiskers of sodium oleate-modified magnesium oxide and magnesium borate in a ratio of 2:1) 6 6 Silica powder 3 7 methyl ethyl carbonate 8

[0027] The interface strengthening agent application method of this embodiment 1 includes the following steps:

[0028] (1) Mix water-based latex and emulsified asphalt evenly to obtain mixed emulsion A;

[0029] (2) The reinforcing agent and the dispersant are mixed to obtain the enhanced pre-reaction liquid B, and modified nickel slag powder, ultrafine silicon material and magnesium-based stabilizer are added to form the reaction enhancement liquid C;

[0030] (3) Finally, mix the mixed emulsion A and the reaction strengthening liquid C evenly, apply it to the well wall, and form a solid body after the reaction.

[0031] Example 2

[0032] The composition of the interface strengthening agent in this Example 2 is shown in Table 2 below.

[0033] Table 2 Interface strengthening agent of Example 2

[0034] Serial Number raw material Content / serving 1 Epoxy Acrylic Emulsion 30 2 Emulsified asphalt 20 3 benzyl carbamate 10 4 Modified nickel slag powder 8 5 Magnesium-based stabilizer (composite whiskers of sodium oleate-modified magnesium oxide and magnesium borate in a ratio of 1.2:1) 3 6 silica ash 2 7 Ethylene carbonate 6

[0035] The application method of the interface strengthening agent in Example 2 is the same as that in Example 1.

[0036] Example 3

[0037] The composition of the interface strengthening agent in Example 3 is shown in Table 3 below.

[0038] Table 3 Interface strengthening agent of Example 3

[0039] Serial Number raw material Content / serving 1 Styrene-acrylic emulsion 50 2 Emulsified asphalt 30 3 Methyl carbamate 20 4 Modified nickel slag powder 15 5 Magnesium-based stabilizer (composite whiskers of sodium oleate magnesium oxide and magnesium borate in a 3:1 ratio) 8 6 fly ash 5 7 propylene carbonate 8

[0040] The application method of the interface strengthening agent in Example 3 is the same as that in Example 1.

[0041] Comparative Example 1

[0042] Comparative Example 1 is basically the same as Example 1, except that unmodified nickel slag powder is used instead of modified nickel slag powder. The specific component contents are shown in Table 4 below.

[0043] Table 4. Interface strengthening agents of Comparative Example 1

[0044] Serial Number raw material Content / serving 1 acrylic emulsion 40 2 Emulsified asphalt 25 3 dimethacrylate 15 4 Nickel slag powder 12 5 Magnesium-based stabilizer (composite whiskers of sodium oleate magnesium oxide and magnesium borate in a 2:1 ratio) 6 6 Silica powder 3 7 methyl ethyl carbonate 8

[0045] The application method of the interface strengthening agent in Comparative Example 1 is the same as that in Example 1.

[0046] Comparative Example 2

[0047] Comparative Example 2 is essentially the same as Example 1, except that the magnesium-based stabilizer uses a composite whisker of magnesium oxide and magnesium borate, meaning that the magnesium oxide is not modified with sodium oleate. The specific component contents are shown in Table 5 below.

[0048] Table 5. Interface strengthening agents of Comparative Example 2

[0049] Serial Number raw material Content / serving 1 acrylic emulsion 40 2 Emulsified asphalt 25 3 dimethacrylate 15 4 Nickel slag powder 12 5 Magnesium-based stabilizer (composite whiskers of magnesium oxide and magnesium borate in a 2:1 ratio) 6 6 Silica powder 3 7 methyl ethyl carbonate 8

[0050] Performance testing

[0051] The interface strengthening agents prepared in Examples 1-3 and Comparative Examples 1-2 of this invention were formulated and subjected to performance testing after being cured at room temperature for 24 hours. Simultaneously, to simulate the strengthening effect of the interface strengthening agent on the wellbore, a strengthening experiment was conducted on a core sample (original compressive strength of 24 MPa) using the interface strengthening agent. The compressive strength of the core sample was tested after 24 hours of strengthening to verify the bonding strength with the wellbore material. The results are shown in Table 6 below.

[0052] Table 6 Performance results of the interface strengthening agents prepared in Examples 1-3 and Comparative Examples 1-2

[0053] Example Tensile strength / MPa Compressive strength / MPa Bond strength / MPa Elongation at break / % Core compressive strength / MPa Example 1 18.7 22.3 5.5 395 34.5 Example 2 18.3 21.2 5.2 426 33.2 Example 3 19.6 22.8 5.8 374 35.9 Comparative Example 1 12.8 15.3 3.9 287 28.2 Comparative Example 2 12.2 14.1 3.3 261 26.3

[0054] As shown in Examples 1 to 3 of Table 6, the interfacial strengthening agent prepared by adding reinforcing agents, ultrafine silica materials, and dispersants to water-based latex and emulsified asphalt, and further compounding with modified nickel slag powder and magnesium-based stabilizers, significantly improves the performance of the material system itself. The tensile strength is above 18 MPa, the elongation at break is above 370%, the compressive strength is above 21 MPa, and the bond strength is above 5 MPa. Furthermore, coating it onto rock cores effectively improves the compressive strength of the cores, indirectly verifying its ability to effectively bond with wellbore materials, enhance the compressive strength of the wellbore materials, and effectively plug leaks.

[0055] In addition to the above embodiments, the technical effects claimed by the present invention can be achieved by using the raw material components and processes defined in the present invention, and therefore no further testing and verification are required.

Claims

1. An interface strengthening agent, characterized in that, The raw materials include the following by weight: 30-50 parts of water-based latex, 20-30 parts of emulsified asphalt, 10-20 parts of reinforcing agent, 8-15 parts of modified nickel slag powder, 2-8 parts of magnesium-based stabilizer, 1-5 parts of ultrafine silica material, and 5-10 parts of dispersant; wherein the magnesium-based stabilizer is sodium oleate modified magnesium oxide and magnesium borate whiskers in a weight ratio of (1-3):

1.

2. The interface strengthening agent according to claim 1, characterized in that, The water-based latex is selected from one or more of acrylic emulsions, styrene-acrylic emulsions, and epoxy acrylic emulsions.

3. The interface strengthening agent according to claim 1, characterized in that, The reinforcing agent is selected from one or more of dimethacrylate, methylcarbamate, and benzylcarbamate.

4. The interface strengthening agent according to claim 1, characterized in that, The modified nickel slag powder is prepared by the following steps: after grinding the nickel slag powder, add 10-20% of ammonium sulfate solution (by weight of the nickel slag powder) and modify it at 60-80 ℃ for 3-4 h, then add 1%-3% of stearic acid (by weight of the nickel slag powder), and finally stir at 80-100 ℃ for 30-60 min for surface activity treatment.

5. The interface strengthening agent according to claim 1, characterized in that, The ultrafine siliceous material is selected from one or more of silica fume, fly ash, and silica powder, with a fineness of 300 mesh or more.

6. The interface strengthening agent according to claim 1, characterized in that, The dispersant is selected from one or more of propylene carbonate, ethylene carbonate, and ethyl methyl carbonate.

7. The interface strengthening agent according to claim 1, characterized in that, The sodium oleate-modified magnesium oxide is prepared by the following steps: first, sodium oleate accounting for 2-5% of the mass of magnesium oxide powder is dissolved in ethanol to obtain a sodium oleate dispersion; then, magnesium oxide powder is added, and the mixture is mechanically stirred for 10-15 min at a speed of 500-1000 r / min, and then ultrasonically dispersed for 10-20 min to obtain a sodium oleate-modified magnesium oxide slurry with a concentration of 5-10 wt%.

8. The application method of the interface strengthening agent according to claim 1, characterized in that, Includes the following steps: (1) Mix water-based latex and emulsified asphalt evenly to obtain mixed emulsion A; (2) The reinforcing agent and the dispersant are mixed to obtain the enhanced pre-reaction liquid B, and modified nickel slag powder, ultrafine silicon material and magnesium-based stabilizer are added to form the reaction enhancement liquid C; (3) Finally, mix the mixed emulsion A and the reaction strengthening liquid C evenly, coat it on the well wall, and form a solid body after reaction.