RU2268989C2 - Grouting mortar reagent, grouting mortar and well cementing method - Google Patents

Abstract

FIELD: oil and gas well building, particularly methods or devices for cementing, for plugging holes, crevices or the like.

SUBSTANCE: grouting mortar reagent includes 99.5-99.9% by weight of amorphous alumina and 0.1-0.5 % by weight of effusive rock-based additive. The grouting mortar comprises cement, water and above reagent taken in amount of 0.05-4.5 % by cement weight. The grouting mortar may additionally have fluid loss reducer, plasticizer and antifoaming additive. Above grouting mortar is used for well cementation.

EFFECT: increased efficiency of grouting mortar reagent used as structure-forming and accelerating agent and containing no aggressive component, namely chlorine ions; provision of grouting mortar expansion and free water retention, extended temperature range of grouting mortar usage, improved adhesion between cement stone and string and rock, possibility to obtain noncontracting cement stone having uniform structure, low porosity and increased corrosion resistance.

6 cl, 1 tbl, 8 ex

Description

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

Known additives of salt accelerators for grouting mortar, such as CaCl ₂ , NaCl, AICI ₃ , etc., grouting mortar with these additives and cementing method using grouting mortar containing the above additives (Akhrimenko V.E., Shirokorodyuk T.V. , Bely V.I. Cement mortars for fastening low-temperature wells // Construction of oil and gas wells on land and at sea. - 2000. - No. 12. - P.16-18).

But accelerator salts and their compositions do not retain free water and contain chlorine ions that cause corrosion of the well string.

Known reagent for cement slurries containing aluminum pentaoxychloride 99.5-99.8 wt.% And superplasticizer 0.2-0.5 wt.%. (Pat. No. 2129649 RF), as well as cement slurry, which includes aluminum oxychlorides (A.S. No. 13218482 of the USSR).

However, aluminum oxychlorides (including pentaoxychloride) are not accelerators for the setting and thickening of grouting systems at temperatures from -5 ° C to + 40 ° C. In addition, they contain chlorine ions, so when using cement slurry with oxychlorides, corrosion of casing will intensify.

The closest technical solution is cement grout according to US Pat. No. 2191251 of the Russian Federation, which includes cement, polyanionic cellulose, ethyl silicate and water, additionally it contains amorphous alumina in an amount of 0.2-3.0 wt.h.

This solution, due to the absence of a structure-forming and expanding additive in its composition, does not provide sufficient adhesion of the stone to the column and rock during cementing and to obtain a non-shrink stone of a homogeneous structure with low porosity.

The objective of the invention is the creation of an effective reagent for cement slurries, which is a structure-forming accelerator that does not contain an aggressive component (chlorine ions), which provides the expansion of the grouting mixture and the retention of free water and works in the temperature range from -5 ° C to + 40 ° C, and cement slurry and cementing method for wells providing good adhesion of the stone with the column and rock, obtaining a non-shrinking stone of a homogeneous structure with low porosity and high corrosion resistance bone.

The essence of the invention lies in the fact that the reagent for cement slurry, including amorphous alumina, additionally contains an additive IR-1 based on volcanic rock in the following ratio, wt.%:

amorphous alumina 99.5-99.9 IR-1 0.1-0.5

The cement slurry contains cement, water and the inventive reagent in an amount of from 0.05 to 4.5% by weight of cement.

Additionally, the specified cement slurry may contain a loss of water in an amount of 0.2-0.8% by weight of cement, a plasticizer in an amount of 0.1-5.0% by weight of cement and an antifoam in an amount of 0.01-0.5% by weight cement.

The essence of the proposed method of cementing is that the cementing of the well is carried out using the inventive cement slurry. The cement slurry used during cementing may additionally contain a loss of water loss in an amount of 0.2-0.8% by weight of cement, a plasticizer in an amount of 0.1-5.0% by weight of cement, an antifoam in an amount of 0.01-0.5% by weight of cement.

The structure-forming and expanding additive IR-1 is produced according to TU No. 5743-001-44628610-98 and contains in wt.%: Volcanic rock (with a ratio of silicon oxide: aluminum oxide of more than 3.5) - 40-85, gypsum 10-35, dolomite - 0-30, silica fume 0-5, plasticizer 1-3.

Methyl cellulose (MC) or hydroxyethyl cellulose (OEC, Sulfacell) can be used as a fluid loss reducer.

The plasticizer can be a reagent C-3, defoamers - well-known reagents TBP, Laprol.

The new claimed combination of known components within their content in the mixture provides a technical result - the ability of the reagent to work as part of a cement slurry at low and negative temperatures, to ensure the stability of the mortar and stone, to facilitate the production of a durable, non-shrinkable cement stone in the cementing process, taking into account the geological and technical characteristics of the well with high corrosion resistance. At the same time, due to the synergistic effect of the interaction of the claimed components with each other, there is a much greater ability to hold water and gain strength in the structure of cement slurry and stone, not achieved when using reagents in other compositions.

The improvement of these indicators guarantees an increase in the quality of cementing of low-temperature wells and permafrost wells, conductors, provides material savings.

The reagent is prepared by gradually administering an IR-1 additive to amorphous alumina to a calculated amount. Then the mixture is stirred until smooth. The reagent is introduced into dry cement or into grouting mortar, which is prepared by a known method of mixing cement with water. Can be used as non-additive cement, for example, grade PTsT G, and additional - lightweight.

Reagent preparation examples:

Reagent No. 1 (P-1) To prepare the reagent P-1 take 99.9 wt.h. amorphous alumina and gradually add 0.1 wt.h. IR-1, thoroughly rubbing and mixing the mixture.

Reagent No. 2 (P-2) To prepare the reagent P-2 take 99.7 wt.h. amorphous alumina and gradually add 0.3 wt.h IR-1, thoroughly rubbing and mixing the mixture.

Reagent No. 3 (P-3) To prepare the reagent P-3 take 99.5 wt.h. amorphous alumina and gradually add 0.5 wt.h. IR-1, thoroughly rubbing and mixing the mixture.

Examples of the preparation of cement slurry

Example 1. For 100 parts by weight of cement, for example, PCT 1 G, take 40 parts by weight water and 0.05 parts by weight reagent R-1. The solution is thoroughly mixed.

The resulting grouting mortar and stone are tested according to existing GOSTs. The test results are presented in table 1, experiment 1.

Example 2. For 100 parts by weight cement, for example PCT1-100, take 50 wt.h. water and 2 g of reagent R-2. The solution is thoroughly mixed.

The resulting grouting mortar and stone are tested according to existing GOSTs. The test results are presented in table 1, experiment 2.

Example 3. For 100 parts by weight cement, for example, PCT 1 G, take 40 parts by weight of water and 4.5 g of reagent R-3. The solution is thoroughly mixed.

The resulting grouting mortar and stone are tested according to existing GOSTs. The test results are presented in table 1, experiment 3.

Example 4. For 100 parts by weight of cement, for example, PCT 1-100, take 50 parts by weight water, 0.5 parts by weight reagent R-1, 0.2 wt.h. OEC and 0.01 parts by weight TBF. The solution is thoroughly mixed.

The resulting grouting mortar and stone are tested according to existing GOSTs. The test results are presented in table 1, experiment 4.

Example 5. For 100 parts by weight cement, for example, PCT 1-100, take 50 wt.h. water, 1 parts by weight reagent R-2, 0.8 wt.h. MC and 0.05 parts by weight Laprol. The solution is thoroughly mixed.

The resulting grouting mortar and stone are tested according to existing GOSTs. The test results are presented in table 1, experiment 5.

Example 6. For 100 parts by weight of cement, for example, PCT 1-100, take 50 parts by weight water, 2 parts by weight reagent R-2, 0.4 wt.h. Sulfacella, 0.2 parts by weight of C-3 and 0.5 parts by weight of Laprol. The solution is thoroughly mixed.

The resulting grouting mortar and stone are tested according to existing GOSTs. The test results are presented in table 1, experiment 6.

Example 7. For 100 parts by weight cement, for example PCT -ob., take 67 wt.h. water, 1 parts by weight reagent R-1 and 0.1 wt.h C-3. The solution is thoroughly mixed.

The resulting grouting mortar and stone are tested according to existing GOSTs. The test results are presented in table 1, experiment 7.

Example 8. For 100 parts by weight of cement, for example, PCT-vol., Take 67 parts by weight water, 3 parts by weight reagent R-3, 0.4 wt.h. and 0.5 wt.h C-3. The solution is thoroughly mixed.

The resulting grouting mortar and stone are tested according to existing GOSTs. The test results are presented in table 1, experiment 8.

Table 1 Example No. Type of binder Cement additives, wt. % W / C D cm ρ, g / cm ³ Water separation, cm ³ Dates of seizure., Beg / con, h-min Strength after 48 days., MPa Adhesion, MPa T *, ° C Reagent Water loss reducer Plasticizer Antifoam agent δ ex. δ is compressed. one. PCT 1 G R-1
0.05 - - - 0.4 21.5 1.89 0.2 1-35
2-50 3.84 10,4 23.0 40 2. PTs1-100 R-
22.0 - - - 0.5 20.5 1.82 0.15 1-55
2-30 3.85 11.15 21.0 40 3. PCT1 G R-3
4,5 - - - 0.4 21.5 1.85 0.1 3-45
4-00 2.1 8.1 20,0 5 four. PTs1-100 R-1
0.5 OEC
0.2 - TBF 0.01 0.5 21.5 1.82 0 5-10
6-05 2,4 3,5 18.0 25 5. PTs1-100 R-2
1,0 MC
0.8 - Laprol 0.05 0.5 20.5 1.83 0 4-30
4-45 4.1 9,4 19.5 40 6. PTs1-100 R-2
2.0 Sulfacell s-30.2 Laprol 0.5 0.5 21.5 1.82 0 5-15
6-20 5,0 11.2 19.9 40 7. PCT about. R-1
1,0 S-30.1 0.67 22.0 1,53 0.1 7-00
9-00 4.1 9.9 20,0 40 8. PCT about. R-3
3.0 s-30.5 0.67 22.0 1,53 0.1 5-40
6-40 3.15 6.7 22.0 5 Prototype 0.5 22.0 1.82 7.2 6-30
9-12 3.9 6.5 10.0 40 * - test temperature

Claims (6)

1. The reagent for cement slurry, including amorphous alumina, characterized in that it further contains an additive IR-1 based on volcanic rock in the following ratio, wt.%: Amorphous Alumina 99.5-99.9 IR-1 0.1-0.5 2. A cement slurry comprising cement, water and a reagent containing amorphous alumina, characterized in that as said reagent it contains the reagent according to claim 1 in an amount of from 0.05 to 4.5% by weight of cement. 3. The grouting mortar according to claim 2, characterized in that it further comprises a loss of water loss in an amount of 0.2-0.8% by weight of cement. 4. Grouting mortar according to claim 2 or 3, characterized in that it further comprises a plasticizer in an amount of 0.1-5.0% by weight of cement. 5. Grouting mortar according to any one of claims 2 to 4, characterized in that it further comprises an antifoam in an amount of 0.01-0.5% by weight of cement. 6. A method of cementing a well using a grout, including cement, water and a reagent containing amorphous alumina, characterized in that the grout is used as a grout according to any one of claims 2-5.