SU1224398A1 - Foam-cement plugging composition for cementing wells - Google Patents

Description

The invention relates to the oil and gas industry, in particular, to lightweight tampon compositions, mainly for well testing, including offshore, under conditions of weakly cemented rocks, abnormally low formation pressures and saline waters.

The aim of the invention is a new gas-holding design. the ability of the solution to increase the strength of the foam stone in bending and expansion cement for cold wells

shutter

50 80 (Sea water of the Barents Sea)

A mixture of sodium dodecyl benzene sulfonate and sodium alkyl sulfates

Mineral fibers having a highly developed surface are 3 (1) (}) effective matrix builder of cement slurries, promote good foaming, well stabilize dispersed gas bubbles in solution, giving it an increased barostability. Additional complex stabilized gas bubbles contribute to also condensed solid

cracking and crack resistance.

The composition is prepared in a skinny manner.

C. Tampon dement add mineral fiber and mix thoroughly. Separately, liquid glass and a mixture of sodium dodecylbenzenesulfonate and sodium alkyl sulfates are successively added to the sealing fluid. The resulting liquid is sealed with a grouting mixture and air is introduced into that composition.

Table 1 shows examples of the proposed composition.

 Tablida

100

100

100

00

(Chlorine Magnesium Bur.)

0.5

1.5

3.0

for, obtained from saline seawater with mixing in the sol-, gel-like products of Mg (OH) 2, Si (OH), with the addition of liquid glass.

Thus, the effective complex stabilization of dispersed air bubbles (gas) in the solution ensures the simultaneous presence of microstabilizers (condensed solid phase) and

macro stabilizers (mineral fibers). The presence in the solution of micro and macro stabilizers in conjunction with dispersed gas bubbles dramatically increases its plugging ability. In addition, mineral fibers effectively reinforce foam cement stone, increasing its treshine resistance, bending and stretching strength, reduce the thermal conductivity of wet stone by about 0.1 W / m. Sodium shady glass in contact with C-padded cement components provides in early the age of the overgrowth of large pores between gas bubbles in the structure of the stone, which leads to a decrease in its permeability and increased dissociation capacity. The late terms of hardening in the structure of the stone; gel-like proIon composition of the water of the Barents Sea

128-130 400-400.8 1313 2700 10600 330 18900 35000 1026 7.9-8.2

Table 3 shows the results of laboratory tests of 24398

The product, for example, MgCOlDj, transforms into the mineral brucite, which additionally strengthens the foam stone. The presence of compressed gas bubbles leads to the expansion of the foam-cement mortar in the basement, and the resulting brucite leads to the expansion of the foam-cement stone, which in general ensures reliability and durability.

10 cementing wells.

Mineral fibers of natural asbestos GOST 12871-67, basalt fibers and alkali resistant glass fibers were used in the experiments.

15 A mixture of surfactants. sodium dodecylbenzenesulfonate and sodium alkyl sulfates are available in accordance with OST 38-706-72 and OST 6-15-1012-76. Marine was used as a mixing fluid.

20 water of the Barents Sea (Table 2) and chlorine-magnesium drilling mud.

Table 2

composition compared to the composition of the prototype.

TablcZ

Foamed Stone

1.5

00

0.5

t.5

100

0.38

1.5

100

0.28

Continuing taba.E

Claims (1)

FOAM-CEMENT TUGGING COMPOSITION. FOR CEMENTING OF WELLS, containing cement slurry for cold wells, grouting fluid, liquid and solid emulsifiers, sodium liquid glass and air, characterized in that, in order to increase the gas-holding ability of the mortar, increase the strength of the foam cement and the stone during bending as well as crack resistance, it contains mineral fiber as a solid emulsifier and a mixture of sodium dodecylbenzenesulfonate and sodium alkyl sulfates as a liquid emulsifier the following ratio, mass parts .: Well cement for cold wells Mixing fluid Mixture of sodium dodecylbenzenesulfonate and sodium alkyl sulfates Mineral fiber Sodium water glass Air 100 50-100 0.5-3.0 1.0-5.0 1.0-4.0 0.015-5.0 SU „„ 1224398