RU2588066C1 - Grouting mortar for cementing and side shafts with horizontal sections - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, particularly to drilling oil and gas wells, and can be used for attachment of oil and gas wells and side shafts with horizontal and inclined sections under conditions of normal temperature. Backfill composition as binding alumina cement and additionally contains quartz sand, unslaked lime, superplasticiser S-3, reagent-stabiliser and water loss reducer - 1 % solution of hydroxyethyl cellulose, antifoaming agent Penta-465 and water in following ratio, wt%: portland cement - 55-65, alumina cement - 10-20, unslaked lime - 5-10, quartz sand - 15-20, said superplasticiser - 1-1.3, hydroxyethyl cellulose - 0.2-0.3, said antifoaming agent - 0.05-0.1, water - balance.

EFFECT: technical result is improved quality and offshoots.

1 cl, 1 tbl, 6 ex

Description

The invention relates to the oil and gas industry, in particular to the field of drilling oil and gas wells, and can be used for fastening oil and gas wells and sidetracks with horizontal and inclined sections at normal temperatures.

Well-known cement for low-temperature wells "arcement" (RF patent No. 2144977, publ. 01/27/2000), containing, wt.%: Portland cement - 48-80, alumina cement grade "400" - 20-50, alkaline chloride salt or alkaline earth metal - 4-6, the technical modified lignosulfonate plasticizer - LSTM (C-3, H-1) - 0.15-0.7.

The disadvantage is the low spreadability and, accordingly, low pumping ability, which will not allow it to be used in conditions of small dimensions of the annular space of the side shafts.

A well-known cement composition (copyright certificate SU No. 1802087, publ. March 15, 1993) for cementing low-temperature wells, containing, wt.%: Portland cement 50-65, fly ash - 20-32, sodium and / or calcium sulfate - 2 -8, hydrosil - 9-14.

The disadvantage is low spreadability and the presence of water separation.

Known polymer-cement grouting mortar (RF patent No. 2319722, publ. March 20, 2008) containing cement, a polymer additive and water, as an additive contains a fluid loss reducer - CFL-117 and hardening and adhesive - Constrol in the following ratio, weight.h .: cement 100, CFL-117 0.4-0.8, Constable - 0.6-1.0, water 42-50. The cement slurry may additionally contain a mineral expanding additive, for example DR-100 - 5-10, parts by weight, the solution is intended for use in moderate temperatures (75 ° C).

The disadvantage is the lack of sedimentation stability, high yield in normal temperatures (30 ° C). In laboratory studies of this grouting mortar, a channel with a mixing fluid was formed in a horizontal cylinder near the upper wall.

A well-known grouting mortar (RF patent No. 2149981, publ. May 27, 2000) containing cement, hydroxyethyl cellulose, an additive based on polymer resins and water, as an additive based on polymer resins, it contains a melamine-containing product, and high viscosity grades as hydroxyethyl cellulose OEC, the viscosity of a 2% solution of which is at least 6000 MPa · s, with the following ratio of ingredients, parts by weight: cement 100, hydroxyethyl cellulose 0.3-0.5, melamine-containing product 0.5-1.0, water 40-50. As a melamine-containing product, it contains a melamine-formaldehyde resin or a mixture based on melamine resins. Additionally, the solution contains an organosilicon product ethyl silicate condensate. The grouting mortar is intended for use at moderate temperatures (100 ° C).

The disadvantage of this composition is that at normal temperatures (30 ° C), the well-known cement slurry has insufficient sedimentation stability, according to GOST 26798.1-96, the water loss is 0.6 ml. As a result, the use of this solution will not allow to provide high quality cementing horizontal wells.

Well-known grouting material based on Portland cement grouting (PCT) (Danyushevsky BC, Aliev PM, Tolstykh I.F. Reference Manual for grouting materials. - 2nd ed., Revised and enlarged. - M .: Nedra, 1987. - p. .373; p. 157), adopted as a prototype, in which gypsum-alumina expanding cement (HGRC), which is a product of co-grinding of high-alumina slag (VGS) and two-water gypsum in a ratio of 3: 1, is used as an expanding additive. A method of preparing this grouting material involves preparing a dry mixture of PCT and HGRC in a ratio of 75-85 and 25-15 wt.%, Respectively, followed by mixing with water. The grouting composition is designed for normal temperatures and has zero water separation, which will allow its use in cementing horizontal wells.

The disadvantage is rapid thickening, after 60 minutes after the beginning of mixing, the consistency of the solution reaches 36 Bs, which will not allow it to be pumped into the annulus. As well as the lack of expansion and, therefore, low adhesive strength to steel.

The technical result is to increase the quality of fastening of wells and sidetracks with inclined and horizontal sections. Reliable sealing of the annulus is achieved by increasing the sedimentation stability of the cement slurry, reducing the time of thickening and hardening without reducing the pumping ability, as well as the presence of expansion of the cement stone during hardening.

The technical result is achieved by the fact that the grouting composition as an aluminate binder contains alumina cement and additionally contains quartz sand, quicklime, C-3 superplasticizer, stabilizer reagent and water loss reducer - 1% solution of 400 grade hydroxyethyl cellulose, Penta-465 antifoam and water, parts by weight:

Portland cement 55-65 alumina cement 10-20 quicklime 5-10 quartz sand 15-20 superplasticizer C-3 1-1.3 400% 1% hydroxyethyl cellulose solution 20-30 Penta-465 defoamer 0.05-0.1 water thirty

Grouting mortar for fastening wells and sidetracks with horizontal sections is illustrated in the table - the properties of grouting mortar and stone.

As starting components for the preparation of grouting mortar, Portland cement grade PPT-I-50 (GOST 1581-96) is used.

As a plasticizer, a 30% solution of S-3 superplasticizer TU 5745-001-97474489-2007 is used, which is a mixture of polymer compounds neutralized with sodium hydroxide obtained by condensation of naphthalene sulfonic acids with formaldehyde. Available in dry (brown powder) and liquid form.

As a stabilizer reagent, hydroxyethyl cellulose (HEC) grade 400 (Sulfacell) TU 2231-013-32957739-01, manufactured by CJSC Policell, is used.

Penta-465 silicone antifoam TU 2257-001-0245042-98, which is a 90% self-emulsifying antifoam concentrate, is used as a defoamer. It is effectively used in processes accompanied by abundant or medium foaming, and also prevents excessive foaming when previously introduced into the composition (formulation). Due to the minimum water content in the composition of the antifoam, it is stable during transportation and storage at low temperatures (pour point below -20 ° C).

As an active mineral binder, alumina cement GTS-40 GOST 969-91, manufactured by Pashi Metallurgical and Cement Plant OJSC, was selected.

Quartz sand with a fraction of 0-0.63 mm TU 5711-002-58887893-2013 was used as a mineral additive.

Cement slurry is prepared as follows: alumina cement, Portland cement, sand and quicklime are mixed in known proportions and added to the mixing fluid. The reagents plasticizer, stabilizer and antifoam are previously dissolved in fresh water at a temperature of no more than 20 ° C. In this case, the stabilizer Sulfacell is introduced in the form of a 1% aqueous solution, previously dissolved in warm water (up to 50 ° C) with constant stirring for at least 3 hours. The introduction of Sulfacell reagent as a 1% solution is due to its slow dissolution in water, as a result of which its dry addition is ineffective and the necessary sedimentation stability of the solution is not achieved. At a higher concentration of the additive in the injected solution, it thickens, which also leads to slow dissolution in pure water.

The concentration of reagents in the inventive composition was identified as a result of a series of experimental studies.

The addition of the stabilizing agent Sulfacell in an amount of 0.2% is selected based on the conditions when the water separation of the cement slurry according to GOST 26798.1-96 is equal to zero.

The addition of S-3 superplasticizer in an amount of 1.3% is a generally accepted optimal value that increases the rheological characteristics without significantly reducing the strength of the stone.

Additive antifoam in the amount of 0.05% is recommended by the manufacturer as optimal.

The amount of water introduced into the grouting mixture is determined based on the pumpability conditions and should be at least 30 wt. parts from the mixture. In the case of a smaller amount of water, the pumped ability of the solution decreases, which negatively affects the cementing operation; with an increase in the amount of water, the strength of the obtained stone and its adhesion to adjacent media decrease.

The number of additives of the mineral component of the grouting mixture is selected from the conditions of sedimentation stability, pumpability, strength characteristics and the magnitude of the expansion of groutstone.

The amount of alumina and Portland cement is selected based on the condition that the ratio of their masses be in a range that allows to achieve high sedimentation stability without accelerated thickening of the solution (example: for temperatures of 20-30 ° C, the range is from 0.3 to 0.36; for temperatures 30-40 ° C - from 0.15 to 0.3). If the content of alumina cement at a certain temperature is lower than the given value, water separation is observed in the solution when pouring it into a horizontal cylinder. If the content of HC relative to PCT exceeds the maximum value admissible for the temperature range, a quick setting of the solution occurs, and the strength of the resulting stone decreases sharply. The sand additive is selected based on the pumpability and strength of the resulting stone, an increase in its content has a positive effect on the pumpability of the solution, when the content exceeds 20%, the stone strength decreases. The addition of lime helps to expand the cement stone, increase its strength, and also slows down the process of thickening the mortar. The amount of lime in the solution is selected based on the adhesion of the cement stone to the steel surface. Literary sources mention and also found during laboratory studies that as the linear expansion of cement stone increases to 3-4%, its adhesion increases, and its further increase leads to a decrease in the adhesion force of the stone to the casing.

Cooking Examples

Composition 1. To prepare 1518 g of the grouting composition, a dry mixture is prepared, for which Portland cement ПЦТ-I-50 is taken - 550 g, alumina cement ГЦ-40 - 200 g, quicklime - 50 g, quartz sand - 200 g. Next, the dry mixture closes in a mixing fluid, consisting of 13 g of S-3 superplasticizer, 200 g of a 1% pre-prepared solution of brand 400 hydroxyethyl cellulose, Penta defoamer 465 - 5 g and 300 g of water. The test results for the cement slurry and the resulting stone are shown in Table . one.

Composition 2. To prepare 1518 g of the grouting composition, a dry mixture is prepared, for which Portland cement ПЦТ-I-50 is taken - 550 g, alumina cement ГЦ-40 - 200 g, quicklime - 70 g, silica sand - 180 g. Next, the dry mixture closes in a mixing fluid, consisting of 13 g of S-3 superplasticizer, 200 g of a 1% pre-prepared solution of brand 400 hydroxyethyl cellulose, Penta defoamer 465 - 5 g and 300 g of water. The test results for the cement slurry and the resulting stone are shown in Table . one.

Composition 3. To prepare 1518 g of the grouting composition, a dry mixture is prepared, for which Portland cement ПЦТ-I-50 is taken - 600 g, alumina cement ГЦ-40 - 150 g, quicklime - 50 g, quartz sand - 200 g. Next, the dry mixture closes in a mixing fluid, consisting of 13 g of S-3 superplasticizer, 200 g of a 1% pre-prepared solution of brand 400 hydroxyethyl cellulose, Penta defoamer 465 - 5 g and 300 g of water. The test results for the cement slurry and the resulting stone are shown in Table . one.

Composition 4. To prepare 1518 g of the grouting composition, a dry mixture is prepared, for which Portland cement ПЦТ-I-50 is taken - 600 g, alumina cement ГЦ-40 - 150 g, quicklime - 70 g, quartz sand - 180 g. Next, the dry mixture closes in a mixing fluid, consisting of 13 g of S-3 superplasticizer, 200 g of a 1% pre-prepared solution of brand 400 hydroxyethyl cellulose, Penta defoamer 465 - 5 g and 300 g of water. The test results for the cement slurry and the resulting stone are shown in Table . one.

Composition 5. To prepare 1518 g of the grouting composition, a dry mixture is prepared, for which Portland cement ПЦТ-I-50 is taken - 650 g, alumina cement ГЦ-40 - 100 g, quicklime - 50 g, quartz sand - 200 g. Next, the dry mixture closes in a mixing fluid, consisting of 13 g of S-3 superplasticizer, 200 g of a 1% pre-prepared solution of brand 400 hydroxyethyl cellulose, Penta defoamer 465 - 5 g and 300 g of water. The test results for the cement slurry and the resulting stone are shown in Table . one.

Composition 6. To prepare 1518 g of the grouting composition, a dry mixture is prepared, for which Portland cement ПЦТ-I-50 is taken - 650 g, alumina cement ГЦ-40 - 100 g, quicklime - 70 g, quartz sand - 180 g. Next, the dry mixture closes in a mixing fluid, consisting of 13 g of S-3 superplasticizer, 200 g of a 1% pre-prepared solution of brand 400 hydroxyethyl cellulose, Penta defoamer 465 - 5 g and 300 g of water. The test results for the cement slurry and the resulting stone are shown in Table . one.

Claims (1)

Grouting composition for fastening wells and sidetracks with horizontal sections, including Portland cement and an aluminate binder, characterized in that it contains alumina cement as an aluminate binder and additionally contains quartz sand, quicklime, C-3 superplasticizer, a stabilizing reagent and a water loss reducer - 1% solution of brand 400 hydroxyethyl cellulose, Penta-465 defoamer and water, parts by weight:
Portland cement 55-65 alumina cement 10-20 quicklime 5-10 quartz sand 15-20 superplasticizer C-3 1-1.3 400% 1% hydroxyethyl cellulose solution 20-30 Penta-465 defoamer 0.05-0.1 water thirty