RU2342416C2 - Spreading additive for back-fill material - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention refers to boring of oil and gas wells and can be employed at their cementing. A spreading additive contains shale ashes and additionally a water solvent reagent containing "Krep" and carboxy-methyl cellulose at the ratio of 1.68:1.0 or "Krep" and tri-butyl phosphate at the ratio of 4.3:1.0, or "Krep" and nitrile-trimethyl-phosphonic acid at the ratio of 11.0:1.0, or plasticiser C-3 and sulfacell at the ratio of (4.3-7.8):1.0 at the following ratio of components, wt %: shale ashes 83.3-98.4, the said reagent 1.6-16.7.

EFFECT: control over backfill material spreading, improved characteristics of material spreading, bending and compressing hardness of cement stone and period of cement thickening.

1 tbl, 7 ex

Description

The invention relates to the field of drilling oil and gas wells and may find application in their cementing.

A well-known additive for grouting material containing high aluminate fly ash containing at least 18 wt.% Alumina (SU 1838582 A3, 1993).

A disadvantage of the well-known additive for grouting material is the expansion of the grouting system containing it until it is delivered to the well and the insufficient strength of the resulting cement stone.

Known expanding additive for grouting material containing fly ash from burning coal or lignite and / or from burning oil shale or dump ash from burning the same types of fuel with SiO ₂ content _of not less than 35 wt.% And Al ₂ O ₃ at least 17 wt.%, which determines its activity, that is, the ability to interact with free calcium oxide contained in Portland cement clinker and gypsum (see RU 2120025 A, 1999).

A drawback of such an additive for grouting material is also its expansion before delivery to the well, since with stirring and with increasing temperature during feeding into the well, its expansion decreases, contraction increases and, therefore, the resulting cement stone has low strength characteristics.

The task of the invention is to regulate with the aid of expansion of the cement material over time, reducing the contraction effect of the cement.

The problem is solved in that the expanding additive for grouting material containing shale ash additionally contains a water-soluble reagent containing the composition of the Krep series and carboxymethyl cellulose in the ratio of 1.68: 1.0, or the composition of the Krep series and tributyl phosphate in the ratio of 4 , 3: 1.0, or the composition of the Krep series and nitrilotrimethylphosphonic acid in a ratio of 11.0: 1.0, or C-3 plasticizer and sulfacell in a ratio of 4.3-7.8: 1.0, with the following ratios components, wt.%:

shale ash 83.3-98.4 reagent 1.6-16.7

Plasticizer S-3 is described in TU 5870-005-58042865-05, and sulfacell in TU 2231-013-32957739-01. The number of components in the mixture is determined by the geological and technical characteristics of the well.

The composition of the Krep series based on medium hydrated aluminum salts is selected and prepared depending on the geological and technical conditions of the well in accordance with TU 2231-233-00147001-2001.

The technical result of controlling the expansion of cement material over time is achieved through the interaction of a water-soluble reagent with calcium oxide contained in shale ash and Portland cement to form gel-like compounds that reduce the contracting effect and keep the expansion of cement material at the same level until it is delivered into the well, where it forms high-quality cement stone.

An expanding grouting additive is obtained by mixing the components.

Example 1

Mixed 8.33 kg (83.3 wt.%) Of shale ash obtained by burning oil shale for products from aerated concrete according to the standard EE 01003682, ST 2:97 and 1.67 kg (16.7 wt.%) Of the lining reagent . The resulting additive was mixed with 100 kg of PCT cement, the resulting dry mixture was closed with 38 l of water. The resulting cement slurry was tested according to existing OST and GOST. The test result, see table 1, experiment 2.

Example 2

96.8 wt.% Of the shale ash from Example 1, 2.6 wt.% (4.3) of the C-3 plasticizer and 0.6 wt.% (1) of sulfacell were mixed. The resulting additive was mixed with 100 kg of PCT cement, the mixture was shut with 40 l of water. The test results of the obtained cement slurry and cement, see table 1, experiment 3.

Example 3

98.4% by weight of shale ash from Example 1, 1.3% by weight (4.3%) of the Krep reagent and 0.3% by weight (1) of tributyl phosphate (TBP) were mixed. The resulting additive was mixed with 100 kg of PCT cement, the mixture was shut with 40 l of water. The test results of the obtained cement slurry and cement, see table 1, experiment 4.

Example 4

97.6 wt.% Of shale ash from Example 1, 2.2 wt.% (11) of the Krep reagent and 0.2 wt.% (1) of nitrilotrimethylphosphonic acid (NTP) were mixed. The resulting additive was mixed with 100 kg of PCT cement, the mixture was shut with 40 l of water. The test results, see table 1, experiment 5.

Example 5

94.9 wt.% Of the shale ash from Example 1, 3.2 wt.% (1.68) of the Krep reagent and 1.9 wt.% (1) of carboxymethyl cellulose (CMC) were mixed. The resulting additive was mixed with 100 kg of PCT cement, the mixture was shut with 40 l of water. The test results, see table 1, experiment 6.

Example 6

Mixed 96.7 wt.% Shale ash from example 1, 3.3 wt.% Reagent "Fix". The resulting additive was mixed with 100 kg of cement of the PTsT brand, 40 L of water was closed. The test results of the obtained cement slurry and cement, see table 1, experiment 7.

Example 7

94.7% by weight of shale ash from Example 1, 4.7% by weight (7.8) of C-3 plasticizer and 0.6% by weight (1) of sulfacell were mixed. The resulting additive was mixed with 100 kg of cement of the PTsT grade, 40 L of water was shut. The test results of the obtained cement slurry and cement, see table 1, experiment 8.

The table shows that when comparing the grouting material containing an expanding additive of the claimed composition (experiments 2-8) with the known (experiment 1), there is a noticeable increase in the readings of the expansion of the grouting mortar, the strength of the cement stone to bend and compress, and the increase in the thickening time of cement.

Table 1 The test results of cements and solutions containing an expanding additive of the claimed composition. Application temperature 22-100 ° С in statics, 22-75 ° С in dynamics No. p / p The composition of the grouting material, kg W / T D cm ρ, g / cm ³ Water separation,% Setting time, h-min Thickening time, min Strength Adhesion, MPa Extension% Start end σ _tzg , MPa σ _squ , MPa hardening conditions one 2 3 four 5 6 7 8 9 10 eleven 12 13 fourteen one. PCT - 66 0.38 20.5 1.96 1,0 6-30 7-40 500 4.8 14.9 22 ° C 3.0 0.4 Gypsum - 4 48 h Ash - 30 2. PCT - 100 0.38 19.5 1.96 0 6-00 7-00 200 6.8 21,2 22 ° C 4.2 0.8 Ash - 8.33 48 h Fix - 1.67 3. PCT - 100 0.4 29th 1,954 0 4-50 5-50 one hundred 6.7 18,4 75 ° C 4.6 1,5 Ash - 9.68 T = 75 ° C 24 h SZ - 0.26 P = 30 MPa Sulfatz. - 0.06 four. PCT - 100 0.4 27 1.95 0 6-40 7-30 141 8.0 25.9 65 ° C 3.6 2,5 Ash - 9.84 T = 65 ° C 24 h Support - 0.13 5-25 6-00 120 9.3 29.0 75 ° C 3.2 1,5 TBP - 0.03 T = 75 ° C 24 h 5. PCT - 100 0.4 29th 1,954 0 5-20 6-10 87 6.5 17.8 75 ° C 3,5 2.0 Ash - 9.76 T = 75 ° C 24 h Lining - 0.22 P = 30 MPa NTF - 0.02 6. PCT - 100 0.4 26.5 1.95 0 6-35 7-05 130 5.05 18.7 75 ° C 3.18 1,6 Ash - 9.49 T = 75 ° C 24 h Support - 0.32 P = 30 MPa CMC - 0.19 7. PCT - 100 0.4 23.5 1,958 0 5-00 5-35 178 5.9 19.7 T = 22 ° C 4.0 0.6 Ash - 9.67 T = 22 ° C 48 h Support - 033 P = 15 MPa 8. PCT - 100 0.4 25 1,945 0 6-40 7-20 171 9.5 32.6 T = 75 ° C 3.2 1,5 Ash - 9.47 T = 75 ° C 24 h S-3 - 0.47 P = 30 MPa Sulf - 0.06

Claims (1)

An expanding additive for grouting material containing shale ash, characterized in that it further comprises a water-soluble reagent containing "Fix" and carboxymethyl cellulose in the ratio of 1.68: 1.0, or "Fix" and tributyl phosphate in the ratio of 4.3: 1.0 , or “Fix” and nitrilotrimethylphosphonic acid in the ratio of 11.0: 1.0, or plasticizer C-3 and sulfacell in the ratio (4.3-7.8): 1.0 in the following ratio of components, wt.%: shale ash 83.3-98.4 reagent 1.6-16.7