An additive for cement grouts and its use

Abstract

This invention discloses an additive for cement grouting materials and its application; the additive comprises powder; the powder comprises the following raw material components: rapid-hardening sulfoaluminate cement, clay, high-efficiency water-reducing agent, retarder, anti-dispersant agent, nano-sized silica fume, and early-strength agent; the application of the additive in formation cement grouting materials includes: mixing the additive with the silicate cement uniformly to obtain a first mixture; mixing the first mixture with water uniformly to obtain cement grouting material; wherein the mass ratio of the first mixture to the water is 0.5-0.8:1. Therefore, this embodiment adds the additive formed by various components to silicate cement, which not only improves the compressive strength of the cement formed by the formation cement grouting material, but also facilitates the solidification of the cement grouting material in the formation; it solves the technical problem in the prior art where the grouting range is difficult to control due to the easy loss of traditional cement in loose porous formations.

Description

Technical Field

[0001] This invention belongs to the field of building technology, and in particular relates to an additive for cement grouting materials and its application. Background Technology

[0002] With the continuous advancement of scientific research, grouting technology has become increasingly mature and sophisticated. The performance of grouting materials determines the grouting effect. A good grouting material must possess the following characteristics: high strength, good fluidity, low bleeding rate, no corrosion to reinforcing steel, and good expansion properties before solidification.

[0003] Loose porous formations have large pores and a loose structure, especially water-bearing formations with high water content, which often use cement grout for water sealing and reinforcement. However, traditional cement grout has a long setting time, is prone to loss when injected into the formation, is difficult to control in terms of grouting range, has poor grouting effect, and causes a lot of material waste.

[0004] Therefore, it is urgent to improve cement-based grouting materials to adapt to loose and porous strata and to improve the compressive strength of the cement-solidified stone body. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides an additive for cement grouting materials and its application. When added to cement grout, the additive not only improves the anti-dispersion properties of the cement grout but also accelerates solidification, thereby increasing the compressive strength of the cement after solidification.

[0006] According to a first aspect of the present invention, an additive for cement grouting material is provided, the additive comprising powder; the powder comprising the following raw material components in weight percentages: 60-80% rapid-hardening sulfoaluminate cement; 20-30% clay; 5-10% high-efficiency water-reducing agent; 1-5% retarder; 1-5% anti-dispersing agent; 2-8% nano-sized silica fume; and 1-3% early-strength agent.

[0007] The rapid-hardening sulfate cement is used to reduce the setting time of the cement grout, improve the strength and stability of the cement formed by the grout, and reduce the occurrence of the cement grout being washed away by water flow during grouting of the formation. The clay is used to reduce the water separation of the cement grout and improve its flowability. The nano-sized silica fume is used to improve the lubricity of the cement grout.

[0008] Optionally, the additive further includes: a liquid component; the liquid component comprises component A and component B; component A comprises the following raw material components by mass percentage: sodium acrylate 10-20%; N,N'-methylenebisacrylamide 1%-5%; water 65-84%. Component B comprises the following raw material components by mass percentage: accelerator 1%-5%; water 95-99%.

[0009] Optionally, the retarder includes one or more of calcium lignosulfonate, sodium citrate, sodium tripolyphosphate, and sodium borate. The early-strength agent is triethanolamine. To address the problem of easy loss of traditional cement grout in the formation, this embodiment uses calcium lignosulfonate as a retarder, which can not only effectively improve the dispersion effect of the cement grout but also increase the setting speed of the cement grout; thus, it is beneficial to the formation of cement in loose porous formations.

[0010] Optionally, the high-efficiency water-reducing agent includes one or more of polycarboxylate water-reducing agents, naphthalene-based water-reducing agents, and aminosulfonate water-reducing agents. Preferably, to improve the fluidity and strength of cement grouting materials, the high-efficiency water-reducing agent is a polycarboxylate water-reducing agent or a naphthalene-based water-reducing agent.

[0011] Optionally, the anti-dispersant includes one or more of hydroxypropyl methylcellulose, polyaluminum sulfate, polyacrylamide, and polyferric sulfate. To address the problem of traditional cement grouting materials being easily washed away by water in the prior art, this embodiment selects hydroxypropyl methylcellulose as the anti-dispersant, thereby improving the anti-dispersibility of the cement grouting material in the formation.

[0012] Optionally, component A further includes an adhesive; the adhesive is an epoxy resin.

[0013] Optionally, the accelerator includes one or more of persulfate, diethanolamine, and sodium thiosulfate; wherein the persulfate is sodium persulfate and / or ammonium persulfate.

[0014] According to a second aspect of the present invention, the application of the additive as described in the first aspect in a formation cement grout is also provided, the application comprising: mixing the additive with the silicate cement uniformly to obtain a first mixture; mixing the first mixture with water uniformly to obtain a cement grout; wherein the mass ratio of the first mixture to the water is 0.5-0.8:1. Preferably, in order to improve the compressive strength and setting speed of the cement formed by the cement grout in the formation, the mass ratio of the first mixture to the water is 0.8:1.

[0015] Optionally, when the additive is a powder, the mass ratio of the silicate cement to the additive is 100:5-10. Preferably, to improve the compressive strength and stability of the cement grouting material in the formation, the mass ratio of the silicate cement to the additive is 10:1.

[0016] Optionally, when the additive is a powder and a liquid, the mass ratio of the silicate cement to the additive is 100:15-20; wherein the mass ratio of the liquid to the powder is 0.2-0.5:1; and the mass ratio of component A to component B in the liquid is 0.9-1:1. To improve the water-stopping effect of the cement grouting material in the formation, preferably, the mass ratio of the silicate cement to the additive is 5:1; and the mass ratio of component A to component B in the liquid is 1:1.

[0017] This invention provides an additive for cement grouting materials. The additive comprises powder, which includes the following raw material components by mass percentage: 60-80% rapid-hardening sulfoaluminate cement; 20-30% clay; 5-10% high-efficiency water-reducing agent; 1-5% retarder; 1-5% anti-dispersing agent; 2-8% nano-sized silica fume; and 1-3% early-strength agent. The application of the additive in formation cement grouting materials includes: uniformly mixing the additive with the silicate cement to obtain a first mixture; uniformly mixing the first mixture with water to obtain cement grouting material; wherein the mass ratio of the first mixture to water is 0.5-0.8:1. Therefore, this embodiment adds the additive formed from various components to silicate cement, which not only improves the compressive strength of the cement formed by the formation cement grouting material but also facilitates the solidification of the cement grouting material in the formation; it solves the technical problem in the prior art where the grouting range is difficult to control due to the easy loss of traditional cement in loose porous formations. Detailed Implementation

[0018] Example 1

[0019] The application of an additive for cement grouting material in formation cement grouting material includes: mixing the additive with silicate cement uniformly to obtain a first mixture; mixing the first mixture with water uniformly to obtain cement grouting material; wherein the mass ratio of the first mixture to the water is 0.5-0.8:1.

[0020] The additive is composed of powder, which includes the following raw material components by mass percentage: 60-80% rapid-hardening sulfoaluminate cement; 20-30% clay; 5-10% high-efficiency water-reducing agent; 1-5% calcium lignosulfonate; 1-5% hydroxypropyl methylcellulose; 2-8% nano-grade silica fume; and 1-3% triethanolamine.

[0021] The additive in this embodiment is composed of powder. By adding powder to silicate cement, the anti-dispersion property of cement grout in the formation can be improved based on the synergistic effect of the components in the powder, and the setting time of cement grout can be reduced. This solves the problems in the prior art where traditional cement is easily lost in the loose pores of the formation, resulting in difficulty in controlling grouting in the formation and poor grouting quality. It also improves the compressive strength and stability of cement formed by cement grout in the formation.

[0022] Example 2

[0023] The application of an additive for cement grouting material in formation cement grouting material includes: mixing the additive with silicate cement uniformly to obtain a first mixture; mixing the first mixture with water uniformly to obtain cement grouting material; wherein the mass ratio of the first mixture to the water is 0.5-0.8:1.

[0024] The additive consists of powder and liquid components. The powder comprises the following raw material components by mass percentage: 60-80% rapid-hardening sulfoaluminate cement; 20-30% clay; 5-10% high-efficiency water-reducing agent; 1-5% calcium lignosulfonate; 1-5% hydroxypropyl methylcellulose; 2-8% nano-grade silica fume; and 1-3% triethanolamine. The liquid component comprises two parts: component A and component B. Component A comprises the following raw material components by mass percentage: 10-20% sodium acrylate; 1%-5% N,N'-methylenebisacrylamide; and 65-84% water. Component B comprises the following raw material components by mass percentage: 1%-5% ammonium persulfate; and 95-99% water.

[0025] In this embodiment, the additive is composed of powder and liquid. When grouting is carried out in the formation, the A and B components of the additive in the cement grouting material interact to form a polymer of polyacrylate. This polymer has good compatibility with silicate cement and can bind the silicate cement slurry together well to form polymer cement. This can reduce the loss of cement slurry in water and improve the waterproofing effect of the formation cement.

[0026] Example 3

[0027] The application of an additive for cement grouting material in formation cement grouting material includes: mixing the additive with silicate cement uniformly to obtain a first mixture; mixing the first mixture with water uniformly to obtain cement grouting material; wherein the mass ratio of the first mixture to the water is 0.5-0.8:1.

[0028] The additive comprises powder and liquid components. The powder comprises the following raw material components by weight percentage: rapid-hardening sulfoaluminate cement 60-80%; clay 20-30%; high-efficiency water-reducing agent 5-10%; calcium lignosulfonate 1-5%; hydroxypropyl methylcellulose 1-5%; nano-grade silica fume 2-8%; triethanolamine 1-3%. The liquid component comprises: component A and component B. Component A comprises the following raw material components by weight percentage: sodium acrylate 10-20%; N,N'-methylenebisacrylamide 1%-5%; epoxy resin 5-10%; water 65-84%. Component B comprises the following raw material components by weight percentage: sodium persulfate 1%-5%; water 95-99%.

[0029] Comparative Example

[0030] The application of an additive for cement grouting materials in formation cement grouting materials includes: mixing the additive with silicate cement uniformly to obtain a first mixture; mixing the first mixture with water uniformly to obtain cement grouting material; wherein the mass ratio of the first mixture to the water is 0.5-0.8:1. The additive is water glass.

[0031] The cement grouting material formed by the comparative ratio is used to grout the formation. This cement grouting material not only has a long setting time, but also easily flows out of the formation, making it difficult to control the grouting range, thereby reducing the grouting effect of the formation cement.

[0032] Tests and trials

[0033] Based on the cement grouting materials in Examples 1 to 3 of this invention and the comparative cement grouting materials, grouting was performed on formations with loose pores to form formation cement. The setting time and compressive strength of the formation cement are shown in Table 1.

[0034] Table 1 Performance results of formation cement

[0035] Formation cement solidification time compressive strength Liquidity Example 1 15min 18MPa 30cm Example 2 9s 10MPa - Example 3 12s 15MPa - Comparative Example 1min 12MPa 28cm

[0036] Conclusions: Compared with the conventional cement in the comparative example, Example 1 only added powder, which improved the compressive strength of the cement slurry while ensuring its fluidity; moreover, the setting time was moderate, which is beneficial for the diffusion of the slurry in loose strata. Example 2 added both powder and liquid, which significantly shortened the setting time and ensured the compressive strength of the aggregate, making it suitable for rapid water plugging. The difference between Example 3 and Example 2 is that epoxy resin was added to component A of the liquid in Example 3; after adding epoxy resin, the setting time was short and the strength of the aggregate was improved, making it suitable for water plugging conditions with strength requirements.

[0037] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0038] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0039] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0040] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

[0041] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0043] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An additive for cement grouts, characterized in that, The additive comprises a powder; the powder comprises raw material components in the following mass percentages: fast-hardening sulphoaluminate cement 60-80%; clay 20-30%; high-efficiency water-reducing agent 5-10%; retarder 1-5%; anti-dispersion agent 1-5%; nano-grade silica fume 2-8%; early-strength agent 1-3%, the early-strength agent being triethanolamine; The additive further comprises a liquid; the liquid comprises A component and B component; The A component comprises raw material components in the following mass percentages: sodium acrylate 10-20%; N,N'-methylenebisacrylamide 1%-5%; water 65-84%, The B component comprises raw material components in the following mass percentages: accelerator 1%-5%; water 95-99%.

2. An additive for cement grouts according to claim 1, characterised in that, The retarder comprises one or more of calcium lignosulfonate, sodium citrate, sodium tripolyphosphate and sodium borate.

3. The additive for cement grouts according to claim 1, characterized in that, The high-efficiency water-reducing agent comprises one or more of polycarboxylic acid water-reducing agent, naphthalene series water-reducing agent and aminosulfonate water-reducing agent.

4. The additive for cement grouts according to claim 1, characterized in that, The anti-dispersion agent comprises one or more of hydroxypropyl methylcellulose, polyaluminum sulfate, polyacrylamide and polyferric sulfate.

5. The additive for cement grouts according to claim 1, characterized in that, The A component further comprises a binder; the binder is epoxy resin.

6. The additive for cement grouts according to claim 2, characterized in that, The accelerator comprises one or more of persulfate, diethanolamine and sodium thiosulfate; wherein the persulfate is sodium persulfate and / or ammonium persulfate.

7. Use of an additive as claimed in any one of claims 1 to 6 in a cement slurry for a subterranean formation, characterized in that, comprises: mixing the additive and the portland cement uniformly to obtain a first mixture; mixing the first mixture and water uniformly to obtain a cement grouting material; wherein; the mass ratio of the first mixture to the water is 0.5-0.8:

1.

8. The use according to claim 7, characterized in that, when the additive is a powder, the mass ratio of the portland cement to the additive is 100:5-10.

9. The use according to claim 7, characterized in that, when the additive is a powder and a liquid, the mass ratio of the portland cement to the additive is 100:15-20; wherein the mass ratio of the liquid to the powder is 0.2-0.5:1; the mass ratio of the A component to the B component in the liquid is 0.9-1:1.