A defoaming agent for oil well cement and preparation method thereof

Abstract

The present invention relates to the technical field of oil well cement, and proposes a defoamer for oil well cement and a preparation method thereof, comprising the following raw materials of weight parts: 30-40 parts of silicone oil, 8-10 parts of modified silica, 5-10 parts of emulsifier, 0.5-1 part of thickener, 80-100 parts of water, wherein the modified silica is silica modified by silane coupling agent KH-550 and 2,4-diaminoanisole. Through the above technical scheme, the problems of poor defoaming performance of organosilicon defoamers in the prior art and low compressive strength when applied to oil well cement are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil well cement, and in particular to a defoamer for oil well cement and a preparation method thereof. Background Art

[0002] During cementing operations, a large amount of foam will be generated during mixing and stirring of oil well cement, which is difficult to eliminate and the construction quality cannot be guaranteed. Therefore, defoaming agents are needed to eliminate this risk. With the increasing prosperity of industrial production, defoaming agents have been widely used in all walks of life. There are many types of defoaming agents at home and abroad, but there are few types of defoaming agents specifically for oil well cement slurry systems.

[0003] The application field of silicone defoamers is very wide, and they have good chemical stability and thermal stability. However, in the preparation process of silicone defoamers, silicone oil is difficult to disperse and is difficult to dissolve in water. Therefore, silicone oil has poor dispersion performance in water systems, resulting in a decrease in defoaming performance and a decrease in the compressive strength of oil well cement during application. Summary of the invention

[0004] The invention provides a defoamer for oil well cement and a preparation method thereof, which solves the problems in the related art that the organosilicon defoamer has poor defoaming performance and low compressive strength when used in oil well cement.

[0005] The technical solution of the present invention is as follows:

[0006] The invention provides a defoamer for oil well cement, comprising the following raw materials in parts by weight: 30-40 parts of silicone oil, 8-10 parts of modified silicon dioxide, 5-10 parts of emulsifier, 0.5-1 part of thickener, and 80-100 parts of water, wherein the modified silicon dioxide is obtained by modifying silicon dioxide with a silane coupling agent and 2,4-diaminoanisole.

[0007] As a further technical solution, the silane coupling agent includes one or more of silane coupling agent KH-550, silane coupling agent KH-560, and silane coupling agent A-151.

[0008] As a further technical solution, the silane coupling agent is silane coupling agent KH-550.

[0009] As a further technical solution, the sum of the mass of the silane coupling agent and 2,4-diaminoanisole is 2% to 3% of the mass of silicon dioxide.

[0010] As a further technical solution, the mass ratio of the silane coupling agent to 2,4-diaminoanisole is 1:1~4.

[0011] As a further technical solution, the mass ratio of the silane coupling agent to 2,4-diaminoanisole is 1:3.

[0012] As a further technical solution, the emulsifier is polyether-modified silicone oil.

[0013] As a further technical solution, the polyether-modified silicone oil consists of OFX-0190 polyether-modified silicone oil and OFX-0193 polyether-modified silicone oil.

[0014] As a further technical solution, the mass ratio of the OFX-0190 polyether-modified silicone oil to the OFX-0193 polyether-modified silicone oil is 1:1~9.

[0015] As a further technical solution, the mass ratio of the OFX-0190 polyether-modified silicone oil to the OFX-0193 polyether-modified silicone oil is 1:4.

[0016] As a further technical solution, the thickener includes one or more of hydroxypropyl methylcellulose, sodium alginate, polyvinyl alcohol, and polyvinyl ether.

[0017] The present invention also includes a method for preparing a defoamer for oil well cement, which comprises the following steps: mixing the raw materials uniformly to obtain the defoamer.

[0018] As a further technical solution, the mixing temperature is 100-120° C., and the mixing time is 1-3 hours.

[0019] The working principle and beneficial effects of the present invention are:

[0020] 1. The defoamer in the present invention is composed of silicone oil, modified silicon dioxide, emulsifier, thickener and water. Silicon oil and silicon dioxide can better solve the foam of oil well cement during the construction process and avoid the adverse effects caused by foam. Although silicon dioxide has good foam breaking performance, it will affect the stability of the system after its addition. Therefore, silicon dioxide is modified by silane coupling agent and 2,4-diaminoanisole. The modified silicon dioxide can not only keep the system at a high stability, but also further shorten the defoaming time, improve the foam suppression time of the defoamer and the compressive strength of the oil well cement.

[0021] 2. The emulsifier in the present invention is composed of OFX-0190 polyether-modified silicone oil and OFX-0193 polyether-modified silicone oil with different HLB values, and when the emulsifier is compounded by OFX-0190 polyether-modified silicone oil and OFX-0193 polyether-modified silicone oil in a mass ratio of 1:1 to 9, the defoaming time of the defoaming agent can be further shortened, and the foam suppression time of the defoaming agent and the compressive strength of the oil well cement can be improved. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the following embodiments and comparative examples:

[0024] Silicone oil, model YH-201, purchased from Wuhan Bushe Materials Co., Ltd.;

[0025] OFX-0190 polyether-modified silicone oil and OFX-0193 polyether-modified silicone oil were purchased from Suzhou Antfu New Materials Co., Ltd.;

[0026] The silicon dioxide is fumed silicon dioxide, specification: 5000 mesh.

[0027] Example 1

[0028] A method for preparing a defoamer for oil well cement comprises the following steps:

[0029] 30 parts of silicone oil, 8 parts of modified silica, 0.5 parts of OFX-0190 polyether modified silicone oil, 4.5 parts of OFX-0193 polyether modified silicone oil, 0.5 parts of sodium alginate and 80 parts of water were mixed at 100°C for 3 hours to obtain a defoaming agent. The preparation method of the modified silica is as follows: 50g of silica was added to 600mL of ethanol aqueous solution and mixed evenly, and then 0.5 parts of silane coupling agent KH-550 and 0.5 parts of 2,4-diaminoanisole were added, reacted at 40°C for 80 minutes, filtered, and dried to obtain modified silica.

[0030] Example 2

[0031] A method for preparing a defoamer for oil well cement comprises the following steps:

[0032] 35 parts of silicone oil, 9 parts of modified silica, 0.8 parts of OFX-0190 polyether modified silicone oil, 7.2 parts of OFX-0193 polyether modified silicone oil, 0.8 parts of polyvinyl alcohol, and 90 parts of water were mixed at 110°C for 2 hours to obtain a defoaming agent. The preparation method of the modified silica is as follows: 50g of silica was added to 600mL of ethanol aqueous solution and mixed evenly, and then 0.6 parts of silane coupling agent KH-560 and 0.6 parts of 2,4-diaminoanisole were added, reacted at 50°C for 70 minutes, filtered, and dried to obtain modified silica.

[0033] Example 3

[0034] A method for preparing a defoamer for oil well cement comprises the following steps:

[0035] 40 parts of silicone oil, 10 parts of modified silica, 1 part of OFX-0190 polyether modified silicone oil, 9 parts of OFX-0193 polyether modified silicone oil, 1 part of polyvinyl alcohol, and 100 parts of water were mixed at 120°C for 1 hour to obtain a defoaming agent. The preparation method of the modified silica is as follows: 50g of silica was added to 600mL of ethanol aqueous solution and mixed evenly, and then 0.75 parts of silane coupling agent A-151 and 0.75 parts of 2,4-diaminoanisole were added, reacted at 60°C for 60 minutes, filtered, and dried to obtain modified silica.

[0036] Example 4

[0037] The only difference between this embodiment and embodiment 1 is that the amount of silane coupling agent KH-550 is 0.25 parts and the amount of 2,4-diaminoanisole is 0.75 parts.

[0038] Example 5

[0039] The only difference between this embodiment and embodiment 1 is that the amount of silane coupling agent KH-550 is 0.2 parts and the amount of 2,4-diaminoanisole is 0.8 parts.

[0040] Example 6

[0041] The only difference between this embodiment and embodiment 1 is that the silane coupling agent KH-550 is 0.7 parts and the 2,4-diaminoanisole is 0.3 parts.

[0042] Example 7

[0043] The only difference between this embodiment and embodiment 1 is that the silane coupling agent KH-550 is 0.15 parts and the 2,4-diaminoanisole is 0.85 parts.

[0044] Example 8

[0045] The only difference between this embodiment and embodiment 1 is that the OFX-0190 polyether-modified silicone oil is 2.5 parts and the OFX-0193 polyether-modified silicone oil is 2.5 parts.

[0046] Example 9

[0047] The only difference between this embodiment and embodiment 1 is that the OFX-0190 polyether-modified silicone oil is 1 part and the OFX-0193 polyether-modified silicone oil is 4 parts.

[0048] Example 10

[0049] The only difference between this embodiment and embodiment 1 is that OFX-0193 polyether-modified silicone oil is replaced with an equal amount of OFX-0190 polyether-modified silicone oil.

[0050] Embodiment 11

[0051] The only difference between this embodiment and embodiment 1 is that OFX-0190 polyether-modified silicone oil is replaced with an equal amount of OFX-0193 polyether-modified silicone oil.

[0052] Comparative Example 1

[0053] A method for preparing a defoamer for oil well cement comprises the following steps:

[0054] 30 parts of silicone oil, 8 parts of silicon dioxide, 0.5 parts of OFX-0190 polyether-modified silicone oil, 4.5 parts of OFX-0193 polyether-modified silicone oil, 0.5 parts of sodium alginate, and 80 parts of water were mixed at 100° C. for 3 hours to obtain a defoaming agent.

[0055] Comparative Example 2

[0056] The only difference between this comparative example and Example 1 is that 2,4-diaminoanisole is not added.

[0057] Comparative Example 3

[0058] The only difference between this comparative example and Example 1 is that the silane coupling agent KH-550 is not added.

[0059] Test example

[0060] The performance of the defoamers in Examples 1 to 11 and Comparative Examples 1 to 3 was measured by the following method:

[0061] (1) Defoaming and antifoaming performance: In a 1000mL measuring cylinder, add 200mL of 1.5wt% sodium dodecylbenzene sulfonate aqueous solution, start the circulation pump to bubble until the foam volume reaches 800mL, add 2g of defoaming agent, and after all the foam is eliminated, record the defoaming time, start the circulation pump to bubble again, and record the time when the foam volume reaches 800mL, which is the antifoaming time;

[0062] (2) Cement paste was prepared according to the determination method in GB / T 19139-2012 “Test Methods for Oil Well Cement”, and the compressive strength of the oil well cement was determined, wherein the cement paste consisted of G-grade cement, fluid loss reducer, dispersant, retarder, defoamer, and water in a mass ratio of 100:4:1:1:1:44; wherein the fluid loss reducer was vinyl alcohol, the dispersant was sodium tripolyphosphate, and the retarder was calcium hydrogen phosphate. The G-grade cement was purchased from Shandong Linqu Shengwei Special Cement Co., Ltd.;

[0063] The measurement results are shown in Table 1.

[0064] Table 1 Defoamer performance in Examples 1 to 11 and Comparative Examples 1 to 3

[0065]

[0066] Compared with Example 1, the silica in Comparative Example 1 is not modified, the silane coupling agent KH-550 is not added in Comparative Example 2, and 2,4-diaminoanisole is not added in Comparative Example 3. As a result, the defoaming time of the defoaming agents in Comparative Examples 1 to 3 is longer than that in Example 1, the foam suppression time is shorter than that in Example 1, and the compressive strength of the oil well cement is lower than that in Example 1, indicating that modifying silica with silane coupling agent KH-550 and 2,4-diaminoanisole can shorten the defoaming time of the defoaming agent, and improve the foam suppression time of the defoaming agent and the compressive strength of the oil well cement.

[0067] Compared with Example 1, Examples 4 to 7 change the addition amounts of silane coupling agent KH-550 and 2,4-diaminoanisole. As a result, the defoaming time of the defoaming agent in Examples 6 to 7 is greater than that in Examples 1 and 4 to 5, the foam suppression time is less than that in Examples 1 and 4 to 5, and the compressive strength of the oil well cement is lower than that in Examples 1 and 4 to 5, indicating that when the mass ratio of the silane coupling agent KH-550 and 2,4-diaminoanisole is 1:1 to 4, the defoaming time of the defoaming agent can be further shortened, and the foam suppression time of the defoaming agent and the compressive strength of the oil well cement can be improved.

[0068] Comparing Example 1 with Examples 4 and 5, the results show that the defoaming time of the defoaming agent in Example 4 is shorter than that in Example 1 and Example 5, the foam suppression time is longer than that in Example 1 and Example 5, and the compressive strength of the oil well cement is higher than that in Example 1 and Example 5, indicating that when the mass ratio of silane coupling agent KH-550 and 2,4-diaminoanisole is 1:3, the defoaming time of the defoaming agent is the shortest, the foam suppression time is the longest, and the compressive strength of the oil well cement is the largest.

[0069] Compared with Example 1, Example 10 only adds OFX-0190 polyether modified silicone oil, and Example 11 only adds OFX-0193 polyether modified silicone oil. As a result, the defoaming time of the defoaming agent in Examples 10~11 is longer than that in Example 1, the foam suppression time is shorter than that in Example 1, and the compressive strength of the oil well cement is lower than that in Example 1, indicating that compounding OFX-0190 polyether modified silicone oil and OFX-0193 polyether modified silicone oil can further shorten the defoaming time of the defoaming agent, and improve the foam suppression time and the compressive strength of the oil well cement.

[0070] Compared with Example 1, Examples 8 to 9 change the mass ratio of OFX-0190 polyether-modified silicone oil to OFX-0193 polyether-modified silicone oil. As a result, the defoaming time of the defoaming agent in Example 9 is shorter than that in Example 1 and Example 8, and the foam suppression time is longer than that in Example 1 and Example 8. The compressive strength of the oil well cement is higher than that in Example 1 and Example 8, indicating that when the mass ratio of OFX-0190 polyether-modified silicone oil to OFX-0193 polyether-modified silicone oil is 1:4, the defoaming time of the defoaming agent is the shortest, the foam suppression time is the longest, and the compressive strength of the oil well cement is the largest.

[0071] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A defoamer for oil well cement, characterized in that: The raw materials include the following components in parts by weight: 30-40 parts of silicone oil, 8-10 parts of modified silicon dioxide, 5-10 parts of emulsifier, 0.5-1 part of thickener, and 80-100 parts of water; the modified silicon dioxide is obtained by modifying silicon dioxide with a silane coupling agent and 2,4-diaminoanisole; The sum of the mass of the silane coupling agent and 2,4-diaminoanisole is 2% to 3% of the mass of silicon dioxide; The mass ratio of the silane coupling agent to 2,4-diaminoanisole is 1:3; The emulsifier is polyether modified silicone oil; The polyether-modified silicone oil is composed of OFX-0190 polyether-modified silicone oil and OFX-0193 polyether-modified silicone oil; The mass ratio of the OFX-0190 polyether-modified silicone oil to the OFX-0193 polyether-modified silicone oil is 1:

4.

2. A defoamer for oil well cement according to claim 1, characterized in that: The thickener includes one or more of hydroxypropyl methylcellulose, sodium alginate, polyvinyl alcohol, and polyvinyl ether.

3. The method for preparing a defoamer for oil well cement according to any one of claims 1 to 2, characterized in that: The method comprises the following steps: mixing the raw materials uniformly to obtain a defoaming agent.

4. The method for preparing a defoamer for oil well cement according to claim 3, characterized in that: The mixing temperature is 100-120° C., and the mixing time is 1-3 hours.

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