CN1803968A

CN1803968A - MTC well cementing liquid system

Info

Publication number: CN1803968A
Application number: CN 200510006918
Authority: CN
Inventors: 张兴国; 许树谦; 李跃明; 柳健
Original assignee: Drilling Technology Research Institute of Xinjiang Petroleum Administration
Current assignee: Drilling Technology Research Institute of Xinjiang Petroleum Administration
Priority date: 2005-01-12
Filing date: 2005-01-12
Publication date: 2006-07-19

Abstract

The related well cementing liquid special for MTC technique comprises mainly the ultrafine slag powder with specific surface area as 600-800m2/kg, the drilling fluid, the alkalinity control agent, the disperser, the coagulant and the retarder. Compared with conventional MTC system, the advantages of this invention lie in: 1. high hydration activity without bulk material; 2. well system stability and low-temperature early-strength feature; 3. stable permeability; 4. non-declined strength; 5. well resistance to corrosion from fresh and salt water, CO2 and NaHCO3; 6. non-declined strength at 90Deg after curing fine mouths; 7. nontoxic and little pollution.

Description

MTC well cementing liquid system

Technical field

The present invention relates to oil gas well cementing operation liquid, particularly the well cementation liquid of MTC cementing technology (mud to cement cementing technology).

Background technology

Compare with conventional oil well cement paste cementing technology; MTC (mud conversion grout) cementing technology have cost low, be beneficial to the advantage that improves displacement efficiency, is beneficial to environment protection; therefore; since the nineties in last century; this technology at home and abroad comes into one's own again; and obtained development faster, still, (specific surface area of used slag micropowder is at 180～500m for conventional MTC ²/ kg) there are problems such as high temperature embrittlement, intensity is on the low side, corrosion resistance is not enough, the long term seal performance is bad, be difficult to satisfy the needs of the long-term ordinary production of oil gas well.

For this reason, the problems referred to above that conventional MTC is existed have been carried out the theory and the experimental study of system, and the result shows that conventional slag MTC is because slag particle is thick, and the hydration reaction activity is lower, has to use the OH of high density ^-System is activated, still, the OH of high density ^-Make the system activated simultaneously, also will make the rapid aquation in slag particle surface and make the system rapid coagulation, but, the component of granule interior is then because the abundant aquation of the parcel of outer layer component at this moment, even just there is not an aquation at all, thereby make weak cementation between slag particle become the main source of cured body intensity, its hydrated product particle is thick on the one hand, poor toughness, the intensity of cured body are low, on the other hand, cured body the mechanical property in later stage can since the granule interior hydration reaction proceed be affected, occur to fluctuate.Under hot conditions, this effect is even more serious, therefore, just occur the granule interior component in the slow aquation of subsequent production process, form bigger expansion stress and make the cured body problem of embrittlement voluntarily.

According to above-mentioned result of study, proposed to improve the MTC performance, solved the technical thought of the problem that conventional MTC exists, and by a large amount of theories and experimental study by reducing the slag particle size, develop a kind of new MTC well cementing liquid and be.Field practice is the result show, the problem that this system does not exist conventional MTC to exist can satisfy the requirement of on-the-spot well cementation.

Summary of the invention

The object of the present invention is to provide and a kind ofly solve that conventional MTC intensity is on the low side, the MTC well cementing liquid system of problem such as embrittlement voluntarily under the high temperature, corrosion resistance deficiency, long term seal performance are bad.

Novel MTC of the present invention, it is mainly formed:

The ultrafine slag micro mist

Drilling fluid

Alkalinity control agent: 0.1%～3%

Dispersion agent: 0.1%～3%

Setting accelerator: 0.1%～3%

Retardant: 0.01%～2%

The specific surface area of used ultrafine slag micro mist is at 600～800m ²(conventional MTC, the specific surface area of slag powders is at 180～500m between the/kg ²/ kg).

Wherein, per-cent is the per-cent that each admixture accounts for ultrafine slag micro mist weight.

(1) the high hydration reaction activity by the small size slag particle improves the hydration reaction activity of MTC system, thus solve conventional MTC slag particle thick, need problem with a large amount of short gel materials is short with fixed attention, cured body intensity is on the low side;

(2) the small size slag particle at short notice can be fully, aquation fully, thereby avoided large size slag particle top layer fast hydration under the blood coagulation enhancing effect of the short gel material of high density to make system form intensity and granule interior aquation and in follow-up hydration process, produce the problem that the swelling pressure make cured body embrittlement fully as yet.

(3) for the small size slag particle, the component degree of irregularity that causes owing to the slag particle phase separation structure is lower, so, its particle surface and inner hydration reaction speed will more even, thereby avoid the aquation crackle that causes owing to particle surface, inner aquation speed of response inequality.

(4) high-specific surface area, the high-hydroscopicity by the small size slag particle improves the system stability of MTC and improves the intensity of MTC cured body;

(5) by piling up more closely between the small size slag particle, the compaction rate of raising system, thereby the intensity, the raising system that improve system are resisted the ability that the corrodibility resident fluid is invaded, and then improve its cured body corrosive of anti-local water ability, improve its long term seal performance in the subsequent production process.

(6) slag particle of this size class both can improve the activity of system, the performance of improvement system, can not increase considerably the cost of system again.

Novel MTC of the present invention can select other component for use, as dispersion agent, setting accelerator, retardant and extra material etc. selectively according to the actual conditions in when well cementation.

Novel MTC of the present invention can use the cement of some amount to do the minor glue material.

Novel MTC of the present invention comprises:

A, at least a alkalinity control agent

B, at least a dispersion agent

C, at least a setting accelerator or retardant

Be used for alkalinity control agent of the present invention, dispersion agent, setting accelerator or retardant and all adopt the known chemical products of petroleum industry, material and consumption thereof that it comprises are as follows:

Alkalinity control agent: caustic soda, soda ash etc., 0.1%～3%

Dispersion agent: vinylformic acid, propylene sulfonated hydrocarbon, vinyl group sulfonate terpolymer and analogous products, 0.1%～3%

Setting accelerator: muriate, vitriol, aluminate, silicate etc., 0.1%～3%

Retardant: boric acid, borax, wooden calcium, wooden sodium, tartrate etc., 0.01%～2%

Novel MTC of the present invention compares with conventional MTC technology, has the innovation of following several aspects:

The hydration reaction of a, system is active high, need not to use a large amount of short gel materials

B, good system stability (table 1) and low-temperature high-early strength characteristic (table 2)

C, rate of permeation not in time prolongation and increase (table 3)

D, intensity not in time prolongation and fail (accompanying drawing 1)

E, good anti-fresh water, salt solution, CO ₂, sodium bicarbonate corrosive power (accompanying drawing 2)

5 months intensity of maintenance do not fail (accompanying drawing 3) under f, the 90 ° of high temperature

G, used treatment agent are nontoxic, and be little to the pollution of environment

Table 1 system stability data

Density (g/cm ³)	Bleed (%)	API dehydration (ml)
Density (g/cm ³)	Bleed (%)	API dehydration (ml)	1.2	0	110
1.25	0	98	1.2	0	110
1.25	0	98	1.3	0	96
1.35	0	98	1.3	0	96

Table 2 low temperature early strength (35 ℃)

Density (g/cm ³)	2d(MPa)	3d(MPa)
Density (g/cm ³)	2d(MPa)	3d(MPa)	1.25	9.4	11.5
1.25	9.9	11	1.25	9.4	11.5
1.25	9.9	11	1.25	8.1	12
1.25	9.3	13	1.25	8.1	12
1.25	9.3	13	1.3	14	17.7
1.3	15	16.3	1.3	14	17.7

Development and change (the 1.2g/cm of table 3 cured body rate of permeation ³)

0.5 month	1#	2#	3#
0.5 month	1#	2#	3#	0.5
1	√	√	√	0.5
1	√	√	√	2	√	√	√
3	√	√	√	2	√	√	√
3	√	√	√	4	√	√	√
5	√	√	√	4	√	√	√
5	√	√	√	6	√	√	√
7	√	√	√	6	√	√	√
7	√	√	√	8	√	√	√
9	√	√	√	8	√	√	√
9	√	√	√	16	√	√	√

Annotate: 8MPa pressure reduction, 10min pressure reduction do not drip on the core permeability tester

Description of drawings

The strength development of accompanying drawing 1 cured body in fresh water and simulation corrodibility resident fluid changes

Accompanying drawing 2 cured bodys are at Na ₂CO ₃, NaHCO ₃Strength development in the solution changes

Accompanying drawing 3 interface cementing strengths over time

Embodiment

Take by weighing each ultrafine slag powder, extra material, admixture, oil drilling slurry and water in proportion, then according under state step, the preparation the present invention.

Step 1: ultrafine slag powder and extra material are puddled evenly, be made into dry ash;

Step 2: admixture is added in the entry, fully stir, it is fully dissolved, in solution, add the drilling mud of requirement then, fully stir, it is puddled evenly, form and join slurries;

Step 3: slurries are joined in the dry ash adding, fully stir, be mixed evenly, promptly obtain the present invention.

Claims

1, a kind of MTC well cementing liquid system, it is mainly formed:

The ultrafine slag micro mist

Drilling fluid

Alkalinity control agent: 0.1%～3%

Dispersion agent: 0.1%～3%

Setting accelerator: 0.1%～3%

Retardant: 0.01%～2%

2, the MTC well cementing liquid is according to claim 1, and dispersion agent is vinylformic acid, propylene sulfonated hydrocarbon, vinyl group sulfonate terpolymer and analogous products.

3, the MTC well cementing liquid is according to claim 1, and setting accelerator is muriate, vitriol, aluminate, silicate etc.

4, the MTC well cementing liquid is according to claim 1, and retardant is boric acid, borax, wooden calcium, wooden sodium, tartrate etc.

5, MTC well cementing liquid system as claimed in claim 1 can also further contain consolidating materials such as cement.