RU2281309C2 - Fiber-reinforced grouting mortar - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: reinforced grouting mortar contains, weight parts: grouting Portland cement 100, mineral fiber (asbestos or basalt fibers no longer than 5 mm) 3-4, polyvalent metal salt (calcium chloride) 0.3-0.4, water-soluble polymer (oxyethylated cellulose) 0.1-0.2, and, additionally, rubber crumb 5-7.

EFFECT: improved damping and adhesive properties of grouting mortar, increased sedimentation stability, and prolonged strength of cement stone.

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Description

The invention relates to the field of drilling oil and gas wells.

Known grouting solution for fastening wells containing Portland cement, Korolek, polyoxyethylene, sodium chloride and water [1]. Korolek acts as a reinforcing additive, and a water-soluble polymer enhances the deformability and adhesion of cement stone to the casing.

The disadvantages of the solution are low damping and high filtration rates.

The closest in composition to the proposed one is a dispersed-reinforced cement slurry containing Portland cement, mineral fiber with chrysotile asbestos, an acid salt of a polyvalent metal or a mixture of these salts, silicocrystallite, a water-soluble polymer and water [2]. The effectiveness of the dispersion-reinforced material is achieved by activating the binder with a micro-reinforcing additive in the disintegrator. However, this does not have sufficient damping properties.

The objective of the invention is the improvement of the damping and adhesive properties of cement slurries with their high sedimentation stability and long-term strength of cement stone.

This task is performed by adding to the grouting mortar containing Portland cement, mineral fiber (asbestos or basalt), a polyvalent metal salt and a water-soluble polymer, crumb rubber in the following ratio of components, parts by weight:

Portland cement grouting - 100

Mineral fiber (asbestos or basalt) - 3-4

Rubber crumb - 5-7

Water-soluble polymer (ethoxylated cellulose) - 0.1-0.2

Calcium Chloride 0.3-0.4.

Dispersion-reinforced cementing materials are a mixture of binder and fibrous materials, randomly oriented and evenly distributed throughout the volume and working with the matrix due to their adhesion by increasing the tensile strength of the stone. The addition of rubber crumb improves the elastic properties of cement slurry and cement stone due to the uniform distribution of elastic particles in the volume of the solution and their binding with asbestos fibers, which contributes to the formation of a fibrous structure throughout the volume, i.e. increase its strength and elastic properties. When composing a composite material immediately before use, it is recommended to use rubber crumb and mineral fiber of the following sizes of 1-3 mm and not more than 5 mm, respectively. Water-soluble polymer acts as a filtration reducer and increases the sedimentation stability of cement slurry. Calcium chloride in this case neutralizes the possibility of reducing the strength properties of cement stone during polymer processing.

The compositions and properties of dispersion-reinforced cement slurries are shown in tables 1 and 2, respectively.

An increase in the content of mineral fiber in the solution over 4% and rubber crumb over 6% leads to an increase in the consistency of the solution (table 2), which, in turn, leads to the need to increase the water-water ratio, which is accompanied by a decrease in the strength of the cement stone. In this case, the content of mineral fiber has the greatest influence on the consistency index. Granular filler (crumb rubber) affects the consistency index to a lesser extent, however, it must be borne in mind that the strength of cement stone depends on the dispersion of the filler, that is, the use of coarse rubber crumb leads to a sharp decrease in strength properties.

The lower limit of the concentration of fillers is limited by a decrease in reinforcing and damping properties, as well as in the density of grouting fluid.

The salt content of the polyvalent metal depends on the specific mining conditions and its composition. The use of water-soluble polymers, as a rule, reduces the strength of cement stone, therefore, their content in the grouting fluid is limited by narrow concentration limits sufficient to stabilize the system, but not causing a sharp decrease in the mechanical strength of the stone.

Cement slurries are prepared as follows. The polymer reagent and calcium chloride are dissolved in water, then fillers and Portland cement are added. In production conditions, when cooking, it is necessary to use an averaging tank.

Table 1 Solution number Portland cement Mineral fiber (size no more than 5 mm) Rubber crumb (size 1-3 mm) Calcium chloride Oxyethylated Cellulose Asbestos Basalt fiber one 2 3 - 5 6 7 one one hundred 3 - 5 0.3 0.15 2 one hundred 3 - 6 0.3 0.15 3 one hundred 3 - 7 0.3 0.15 four one hundred four - 5 0.3 0.15 5 one hundred four - 6 0.3 0.15 6 one hundred four - 7 0.3 0.15 7 one hundred 5 - four 0.3 0.15 8 one hundred 5 - 6 0.3 0.15 9 one hundred 5 - 8 0.3 0.15 10 one hundred - 3 5 0.3 0.15 eleven one hundred - 3 6 0.3 0.15 12 one hundred - 3 7 0.3 0.15 13 one hundred - four 5 0.3 0.15 fourteen one hundred - four 6 0.3 0.15 fifteen one hundred - four 7 0.3 0.15 16 one hundred - 5 four 0.3 0.15 17 one hundred - 5 6 0.3 0.15 eighteen one hundred - 5 8 0.3 0.15

The proposed composition of the cement slurry is effectively used in the intervals of permeable rocks to eliminate absorption and repair cementing.

table 2 Solution number Temperature ° C Water ratio Spreadability, cm Density
kg / m ³ Water separation, ml Bending Strength, MP Thickening time hour-min one 2 3 four 5 6 7 8 one 40 0.6 19.5 1690 0,0 3.60 2-45 2 40 0.6 19.0 1670 0,0 3.60 2-50 3 40 0.6 18.5 1650 0,0 3.53 2-55 four 40 0.65 18.5 1600 0,0 3.52 2-52 5 40 0.65 18.0 1600 0,0 3.48 3-05 6 40 0.65 17.8 1590 0,0 3.45 3-15 7 40 0.8 18.0 1500 0,0 1.45 3-55 8 40 0.8 15,5 1500 0,0 1.35 4-40 9 40 0.8 14.0 1500 0,0 1.15 5-05 10 40 0.6 21.0 1690 0.0 3.40 2-56 eleven 40 0.6 20.8 1670 0,0 3.38 3-01 12 40 0.6 20,0 1650 0,0 3.30 3-10 13 40 0.65 20,2 1600 0,0 3.12 3-08 fourteen 40 0.65 19.6 1600 0,0 3.04 3-15 fifteen 40 0.65 19.0 1590 0,0 2.98 3-22 16 40 0.8 19,2 1500 0,0 1.25 4-05 17 40 0.8 16.8 1500 0,0 1.12 5-03 eighteen 40 0.8 15,2 1500 0,0 1,04 5-16

Information sources

1. A.S. USSR No. 1470933, MKI 4 E 21 B 33/138, 04/07/89.

2. A.S. USSR No. 1099049, MKI 3 E 21 V 33/138, 06.23.87.

Claims (1)

Dispersion-reinforced grouting mortar, including grouting Portland cement, mineral fiber, polyvalent metal salt, water-soluble polymer and water, characterized in that it contains asbestos or basalt fiber no more than 5 mm in size, calcium chloride as a polyvalent metal salt, as a water-soluble polymer, ethoxylated cellulose and additionally rubber crumb size of 1-3 mm in the following ratio of components, parts by weight: Portland cement grouting one hundred Specified Mineral Fiber 3-4 Oxyethylated Cellulose 0.1-0.2 Calcium chloride 0.3-0.4 Specified rubber crumb 5-7