SU1700201A1 - Oil-well slurry for saline sediments - Google Patents

Abstract

The invention relates to the drilling of wells. The purpose of the invention is to increase the strength and adhesive properties while increasing the expansion of the cement stone. Cement slurry for well drilling in salt deposits includes cement grout, sodium chloride, water, and, as an additive, alkylbenzyldimethylammonium chloride (katamin AB) in the following ratio of components, May%: grouting cement 71,393-72.990, sodium chloride 2,890-8,084 katamin AB 0.004-. 0,036, water the rest. Alkylbenzyldimethylammonium chloride with the radical R Ctn-C (s (katamin AB) belongs to class Quaternary ammonium salts and is a clear liquid from colorless to yellow. Katamin AB and sodium chloride, when used together, increase the strength (in 1.2- 1.7 times) and adhesion properties (1.5-1.8 times) while simultaneously increasing the expansion of the cement stone. The cement slurry can be effectively used under conditions of normal temperatures (15-50 ° C) 0 1 table. Sya

Description

The invention relates to the drilling of wells, in particular, cement slurries for cementing oil and gas wells in salt-bearing sediments under conditions of normal temperatures.

The purpose of the invention is to increase the strength and adhesive properties while increasing the expansion of the cement stone.

Cement slurry for casing wells in salt-bearing sediments includes cement grout, sodium chloride, water and, as an additive, alkylbenzyldimethylammonium chloride (katamin AB) in the following ratio, wt%:

Grouting

cement

Sodium chloride

Katamin AB

Water

Used in the composition of alkylbenzyldimethylammonium chloride with the radical

71,393-72,990

2,890-8,084

0,004-0,036

Rest

P. C, 0- (katamin AB) belongs to the class of quaternary ammonium salts and is a clear liquid from colorless to yellow. It was experimentally established that katamin AB and sodium chloride, when used together in the proposed solution, increase the strength and adhesion properties while simultaneously increasing expansion of cement stone, showing the effect of joint action.

Studies have shown that the combined use of catamine AB and sodium chloride in cement slurry increases bending strength by a factor of 1.2 to 1.7 compared with a known solution (it is 2.55 - 3.20 MPa, respectively), adhesion to metal - 1.5-1.8 times (1.20 - 1.32 MPa and 1.80-2.30 MPa respectively), and the expansion of the hardening mass reaches + 0.42% against + 0.1% of the known, ,

The cement slurry is prepared as follows.

The estimated amount of cement Portland cement is loaded into the cement mixing machines. The estimated amount of sodium chloride and AB catamine is injected into the shrinking fluid, and is thoroughly mixed with a drilling pump or cementing unit. Casing cementing is carried out along. conventional technology.

For the study of cement slurries in the laboratory, compounds with different content of components were prepared, their boundary and average values were determined

For example, PC. For the preparation of 1 liter of cement slurry according to test 16 (cm0 table), the required number of components is determined by the formula

w V-fl, a,

where m is the mass of the component in 1 liter of cement slurry;

V - volume of cement slurry, l

K - density of cement slurry, l;

a - the content of the component, wt.% 0

2.0-71 416

100

 1428 g of cement

2.0-5.199 1P,

t „---- yyyy - (- cg hporida sodium - iuU

t, 0.36 g of catamine AB

sing

- 7-4

ML WATER

5 0 5

0

Q

Q

five

five

To prepare the cement slurry, 467 ml of water is poured into a separate container and 104 g of sodium chloride and 0.36 g of catamine AB are introduced with constant stirring. The duration of stirring is 3-5 minutes (until complete dissolution of the reagents). 1428 g of cement are placed in another container (spherical bowl) and the aqueous solution of reagents is poured in one step and stirred for 3 minutes.

The physical and mechanical properties of cement slurries are determined according to GOST 1581-85 and GOST 26798 "0-85 - GOST 26798" 2-85.

Volumetric changes in cement slurries are determined by the method using an instrument similar to a device for determining swelling soils.

The adhesive properties of the cement stone with respect to the metal are determined as follows.

A metal beaker of a smaller diameter is placed in a metal beaker with a removable bottom, and the test pressure is poured into the annular space. After 2 days of solidification in water at room temperature, the UMM-5 press squeezes out the inner cup, fixing the value of the force of its detachment from the cement stone.

For the preparation of the cement slurry (known and proposed), grouting Portland cement of grade GSPT D20-50 of the Korkinsky Cement Plant, sodium chloride according to GOST 13830-84, calcium chloride according to GOST 450-77 and katamin AB are used.

The table shows the results of laboratory studies. The table shows that the known compositions containing only sodium chloride, have insufficient strength, adhesion to metal and low value of the expansion of the formed stone (experiments 1-4). Calcium chloride additives to these solutions shorten the setting time, but the strength and expansion properties remain almost at the same level (experiments 5-9). The content of only katamine AB in the in situ solution (experiment 30) hardly improved.

adhesion and expansion of cement stone melts (1.32 MPa + 0.1%), although in comparison with the known, the proposed composition has increased strength when bending (3.8 MPa).

Developed grouting solutions are presented in experiments 10-23. The content of cathamine AB in the range of 0.004-0.036 wt% provides the cement slurry with normal mobility and setting time according to GOST 1581-85 increased bending strength (up to 5.5 MPa), adhesion (up to 2.3 MPa) and expansion of the cement stone ( up to 0.42%).

The content of cathamine AB is less than 0.004 wt0% (experiment 26) does not provide an increase in strength and expansion (and from 2.81 MPa, A 1.26 MPa, AV + 0.1%).

The content of cathamine AB more than 0.036 wt.% (Experiment 27) impairs the mobility of the cement slurry (spreadability 16 cm), making it unsuitable for securing wells.

The optimum content of sodium chloride is determined within 2.890-8.084 wt0%. If the content of sodium chloride is 8.084 wt.%, The saturation limit of the aqueous solution occurs, when the content is less than 2.890 wt.% (Test 29), the cement slurry has small setting values (2 h 30 min), and cement stone is relatively low strength, adhesion and expansion.

The optimum content of cement-cement in the range of 71.393 - 2.990 wt.%: With a cement content of more than 72.990 wt.% (Experiment 26), the cement slurry has a low mobility (16 cm), with a content of less than 71,393 wt.% (Experiment 25), the cement is formed stone has low values of strength, adhesion and expansion. Thus, the cement slurry has the best properties compared with the properties of a known solution, namely: increased strength

I

15

| „

five

20

25

thirty

0

five

properties, adhesive properties, with simultaneous expansion of cement KSMH4,

At t 60CC, short setting times (the start is less than 1 h 45 min, experiments 35-38) allow you to use the tampon solution as well.

At 50 l 5 ° С with satisfactory (within the limits of GOST 1581-85) setting time, strength, adhesion properties and expansion of cement Kam-tg (J0932 и) 5, increased in comparison with a known mortar 5

At t 10 ° С extended setting time 5 low strength and adhesion properties, and cement stone is used by Mouth 43-46) 0

Based on this, it can be argued that the tampant solution can be effectively used under conditions of normal temperatures (15-50 ° C).

The use of cement slurry for cementing casing in saline deposits will allow g - to increase the quality and durability of fastening

Claims (1)

Formula invented and Cement slurry for casing wells in salt deposits, including cement slurry, 9 sodium chloride, water, and an additive, other than 5. in order to increase the strength and adhesive properties while increasing the expansion of the cement stone, it contains alkylbenzyldimethyl chloride in the quality of the additive in the following ratio of chas% components: Grouting cement Sodium chloride Alkylbenzyldimethylammonium chloride (katamin AB) Water 71,393-72,990 2,890-8,084 0,004-0,036 Else Known compounds 0.67 27.73- U 25,3924 22,2824 22.9219 29, 3-405-153, i1.18 + 0.1 5-357-552Ј811, 2 + 0.1 9-4012-402,561.10fO, 1 5-508-00 2,731,10 + 0,1 3-554-202,301,22 + 0,1 Table continuation