RU2194149C1 - Complex reagent for plugging mortars - Google Patents

Abstract

FIELD: oil producing industry; applicable in preparation of plugging mortars in process of oil and gas wells casing. SUBSTANCE: complex reagent includes the following ratio of components, mas.%: sulfacell, 60-90; plasticizer, 9-25; foam suppressor, 1-15. EFFECT: considerable reduction of water loss, absence of foaming, reduced sedimentation, high strength of plugging stone hardening at temperature from 50 to 150 C. 1 tbl, 4 ex

Description

 The invention relates to the oil industry and is used in the process of attaching oil and gas wells in the preparation of cement slurries.

 Known reagents, fluid loss reducers of cement slurries, CMC, MC, etc. [1].

The disadvantage of such reagents is their low heat resistance, as a result of which, at elevated temperatures (from 50 to 150 ^o C), sedimentation and water loss of cement slurry increases, which negatively affects the quality of cement stone.

 A well-known complex reagent for grouting mortars is a fluid loss reducer containing water-soluble hydroxyethyl cellulose (sulfacell) and C-3 superplasticizer [2].

 This reagent also has low heat resistance, causes foaming of cement slurry, which reduces its technological quality (ability to pump into the annulus).

The objective of the invention is the creation of an effective integrated reagent for cement slurries, with the ability to pump the solution into the annulus, reduce its sedimentation and water loss in a wide temperature range (from 50 to 150 ^o C), to help reduce foaming, which in combination affects the strength characteristics cement stone.

The problem is solved in that the claimed complex reagent for cement slurries, including sulfacell and a plasticizer, additionally contains an antifoam in the following ratio of components, wt.%:
Sulfacell - 60-90
Plasticizer - 9-25
Antifoam - 1-15
The new inventive combination of known components within their content in the mixture provides a complex reagent technical result - the ability to significantly reduce the loss of grout, complete elimination of foaming, reduce sedimentation at temperatures from 50 to 150 ^o C.

 In this case, the reagent due to the synergistic effect of the interaction of the components with each other has acquired a much greater ability to reduce water loss than with separate use of the components. Separate use of antifoam also did not completely eliminate foaming of the solution, and this effect was achieved by the claimed composition.

 High heat resistance of the reagent is also achieved due to the mutual influence of the components in the mixture.

 Significant improvements in the characteristics of the grout with the introduction of the inventive complex reagent guarantees an increase in the quality of the resulting cement mortar and stone based on it.

 A complex reagent is prepared by mixing the calculated amounts of sulfacell, plasticizer and antifoam until a mixture is uniform in composition. As a plasticizer, C-3 superplasticizer is used, phosphonic complexones — NTF, OEDF, etc. Any compounds from this class are used as antifoam: organosilicon, phosphate, etc.

 Example 1

 Mixed 90 g of dry sulfacell and 1 g of a 30% solution of antifoam - tributyl phosphate in a mixing device to a homogeneous mass. To the resulting mixture was added 9 g of dry plasticizer C-3 and stirring was continued until a homogeneous mass.

 The resulting reagent in an amount of 0.6% by weight of cement (1 kg) was introduced into 440 ml of a mixing liquid (water) and mixed until it was completely dissolved. After that, cement was added to the solution and mixed in a mixing device. The finished cement slurry was examined for physical and mechanical properties according to the generally accepted OSTs and GOSTs.

 The research results are shown in the table, example 1.

 Example 2

 A cement slurry was prepared according to the method described in Example 1, from 60 g of sulfacell, 15 g of antifoam - tributyl phosphate, 25 g of C-3 plasticizer, 440 ml of water and 1 kg of cement.

 The results of the study of the solution are shown in the table, example 2.

 Example 3

 A cement slurry was prepared according to the method described in Example 1 from 82 g of sulfacell, 4 g of antifoam - tributyl phosphate, 14 g of C-3 plasticizer, 440 ml of water and 1 kg of cement.

 The results of the study of the solution are shown in the table, example 3.

 Example 4

 A cement slurry was prepared according to the method described in Example 1, from 80 g of sulfacell, 5 g of antifoam - glycol and 15 g of NTF plasticizer (nitrilotrimethylphosphonic acid).

 The results of the study of the solution are shown in the table, example 4.

 As indicators of the properties of the claimed reagent taken sludge, water loss, spreadability, strength characteristics of cement stone.

The table shows that the plasticity of the obtained cement mortar is sufficient for its pumpability. There is a sharp decrease in water loss (compared with the known reagent, which is characterized by its value from 300 to 400 cm ^3/30 min), obtained at elevated plasticizing water sink zero, indicating that the sedimentation stability of the solution. In addition, with the introduction of the inventive reagent into the grout, its foaming did not occur.

 The remaining properties of the grouting mortar, indicated in the table, indicate its high technological qualities.

 The use of the proposed reagent for cement slurries will improve the quality of fastening of oil and gas wells and increase their service life.

Used sources
1. A.I. Bulatov. The formation and operation of cement stone in the well. M. Nedra, 1990, p. 149.

 2. Application for a patent of the Russian Federation 97106934/03 of 04/28/97, E 21 B 33/138.

Claims (1)

A comprehensive reagent for grouting mortars, including sulfacell and a plasticizer, characterized in that it further contains an antifoam in the following ratio of components, wt. %:
Sulfacell - 60-90
Plasticizer - 9-25
Antifoam - 1-15

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