Fibre-reinforced plugging material for cementing production intervals subject to perforation during well development

FIELD: oil and gas production.

SUBSTANCE: plugging material contains cement, reinforcing fibre-polyacrylic or polypropylene or basalt fibre, polydiallyldimetylammonium chloride-VPK-402, hydroxyethyl cellulose, super plastifier CEMPLAST or C-3 or Melflux, anti-foaming agent POLYCEM DF, calcium chloride and water with the following component ratio, wt %: cement 65.0-69.0, said reinforcing fibre 0.08-0.33, hydroxyethyl cellulose 0.07-0.2, said super plastifier 0.08-0.33, said anti-foaming agent 0.08-0.13, calcium chloride 0.08-1.3, polydiallyldimetylammonium chloride-VPK-402 0.08-0.33, water the rest.

EFFECT: improvement of crash resistance, including conditions of hard dynamic influences.

1 ex, 2 tbl

 

The invention relates to the oil and gas industry, namely for the construction of wells, including horizontal, in particular the backfill materials used for cementing casing in intervals of productive strata exposed perforating impact in the development process, when the elimination of complications in wells associated with the merger.

Known cement composition for cementing on dispersion-reinforced framework [1]that contains components in the following ratio, parts by weight:

Silicate and/or chlorinity Portland100
The wollastonite and/or fibrous crystals
synthetic of calcium hydro or magnesium3,0-8,0
The mixture of fibrous crystals natural
or synthetic minerals, or
metal fibers, or glass fibers,
or basalt fibers with polypropylene,
or nylon, or nylon,
or polyvinyl alcohol fibers,
taken in the ratio of 1:1-2:12,0-4,0
Liquid silicone polymer type
oligoorganosiloxanes0,05-0,25
Powdered silicone
connection type allylsilanes2,5-8,0
Palygorskite2,0-6,0.
Water for water-cement ratio (W/C)45-75.

The disadvantages of this known structure is its high water segregation, followed by stratification and low flowability, complicating injection grouting composition in directional and horizontal wells.

Closest to the proposed technical solution to the technical essence is a cement composition for cementing wells [2], prepared from the basic fundamentals, contains, wt%:

Cement95,0-98,0
The reinforcing fiber is a polyamide fiber
or a mixture of polyamide fibers with chrysotile asbestos in
the ratio 0,3÷2,0:10,5-4,0
The plasticizer CHEMPLAST, C-3 or Melfluxof 0.05-0.2
Acetylcellulose0,1-0,5
Defoamer POLICEM DF01-02
The accelerator of terms - calcium chloride or
sodium chloridethe rest of it.

At the same time to obtain a cement composition of the base shut water when water-cement ratio of 0.4-0.6.

The disadvantages of this known cement composition are insufficient technological characteristics: tensile strength, compressive strength, Flexural strength and adhesion strength. In field conditions will lead to the formation of cracks in the cement stone, are particularly exposed to the perforation impact in the development process.

The technical result, d is evil in the invention, consists of giving backfill material physical and mechanical properties, improving its resistance to cracking, especially in the conditions of rigid dynamic effects during cementing of productive intervals, subject perforation in the process of development wells, by reinforcement structure at the micro and macro level.

This technical result is ensured offer februaryjune backfill material for cementing productive intervals, subject perforation in the process of development wells, including cement, reinforcing fibers, acetylcellulose, superplasticizer CHEMPLAST MT, or-3, or Melflux, defoamer POLICEM DF, calcium chloride, and water, while the new is that the material further comprises polydiallyldimethyl chloride VPK-402, and as a reinforcing fiber - poly (acrylic, or polypropylene, or basalt fiber, in the following ratio, wt.%:

Cement66,0-69,0
Reinforcing fiber - polyacrylic,
or polypropylene, or basalt0,08-0,33
Acetylcellulose 0,07-0,2
Superplasticizer CHEMPLAST Matt,
or-3, or Melflux0,08-0,33
Defoamer POLICEM DF0.08 to 0.13
Calcium chloride0,08-1,3
Polydiallyldimethyl chloride
VPK-4020,08
Waterthe rest of it.

The achievement of the technical result is ensured by a specific selection of components (qualitative and quantitative) in the inventive cement material, i.e. this result is synergistic in nature.

Thanks to the introduction of the backfill material acetylcellulose provided a low filter, removed sedimentation processes, which ensures zero water segregation obtained of cement slurries. But due to a synergistic effect in conjunction with other components specified rate of filtration is approaching the level of filtration of drilling fluids that will allow in field cementing permeable intervals to eliminate premature agustiana grouting material.

The use of the proposed material as the reinforcing fibers are acrylic, or polypropylene, or basalt fiber allows, along with the increase of elastic-plastic (tensile strength) properties of cement material, to improve the strength properties of the resulting cement stone (compression, bending and adhesion to the breed). Fiber contributes to the improvement of fracture toughness of cement, so as to effectively absorb and relax the dynamic tension. These fibers in the absorption zone to form a network bridge jumper, contributing to the rapid formation of mud cake, preventing the departure of the cement slurry into the formation. Fibers provide education in cement stone microanatomy, which determines the ability of the matrix of cement stone to absorb tensile and impact loads. Due to this, the grouting composition becomes universal and can be used in various formation conditions:

- cementing productive strata production casing, including shank;

for the elimination of acquisitions in permeable sediments;

- cementing technical and operational columns, including the shank, where the borehole section is composed of highly permeable formations, which eliminates the possibility of the use is of lightweight cement compositions and devices for speed cementing.

The last quality is especially valuable because it allows to use the same material in various phases of well construction, which increases the efficiency of construction.

Introduction to the proposed material antifoam allows a reduction of foam formation, which is beneficial to the work of cementing equipment, and also allows you to get better quality cement stone.

The use of superplasticizer in the proposed backfill material allows you to modify the structure of the cement slurry, sealing it, which contributes in turn to increase the strength of cement stone. In addition, included in the plasticizing additive allows you to adjust the rheological parameters of cement during the period of pumping it into the well. The optimal ratio fibroelastoma additives with plasticizing additive allows to solve the problem associated with the need to find a rational balance between mechanical properties and rheology.

Introduction in the proposed grouting composition polydiallyldimethyl chloride VPK-402 provides reinforcement of cement stone at the macro level. Additionally, the reagent has an additional plasticizing effect on the cement.

To obtain the claimed tamponage the th material in the laboratory, we used the following substances:

- cement Portland cement PCT IG-CC-1;

- acetylcellulose brand HYDROCHEM N, WITH THE 2231-009-40912231-2003;

- superplasticizer brands: CHEMPLAST MT (sulfated melamineformaldehyde) TU 2223-011-40912231-2003; C-3 (sodium salt of the condensation product of naphthalenesulfonate with formaldehyde by THE 6-360204229-625-90)

and Meluux - politicalsocial (polycarboxylic esters), water-reducing additive according to the degree of plasticization in accordance with GOST 242111-91 belongs to the group of superplasticizers, manufacturer: Degussa meetings with pre Polymers (SKW Trostberg, Germany); powder product obtained by the method of spray drying on the basis of the modified politicalmoneyline. Technical data: form - yellowish powder; bulk density of 400-600 g/l; loss when heated - max 2.0 wt.%; a 20% solution at 20°C has a pH=6,5-8,5. Features: - high-performance disperser; - reduces shrinkage; - effective in a wide range of temperatures;

- reinforcing fiber:

- polyacrylic fiber: Panacea, FPAC 236/040, issued by JSC "EuroChem-1" (Moscow), Fibrocem B, THE 2458-058-40912231-2009;

polypropylene fiber: VSM P-6 (Seireg Chelyabinsk) THE 2272-006-13429727-2007;

the basalt fiber THAT 5769-004-80104765-2008;

- defoamer POLICEM DF - modified crasneanscki reagent on THE 2228-010-40912231-2003;

- calcium chloride GOST 450-77 with changes 1, 2, 3;

- polidi llillillilli chloride VPK-402 - high molecular weight cationic water-soluble polymer linear-cyclic structure obtained by radical polymerization of the monomer dimethyldiallylammonium chloride; on THE other 2227-184-00203312-98 (var. 1, 2, 3, 4), characterized by a very high cationic charge at a relatively low molecular weight is from 10 thousand to 1 million, resistant to temperatures from -40°C to +60°C, infinitely soluble in water, the viscosity is not less than 2 mm2/s, pH 5-8, the molecular weight of the polymer is 3*105;

- water technical.

The possibility of implementing the claimed invention is confirmed by the following example.

Example. For the preparation of the proposed fibrocartilagenous grouting material in the laboratory took 1000 g of cement PCT I-G-CC-1, was added polyacrylic fiber 2.3 g, acetylcellulose HYDROCHEM WITH 2.3 g, superplasticizer CHEMPLAST 1.3 g, defoamer POLICEM DF 2.3 g, calcium chloride 10 was Obtained tamping the mixture was thoroughly stirred. For preparation of liquid mixing took technical water in the amount of 440 ml) and was dissolved in the amount of 1.3 g polydiallyldimethyl chloride VPK-402. Received the grouting mixture is kneaded prepared liquid was prepared. The result was the grouting composition with the following ratio of components, wt.%: cement and 68.5; p is lacrilube fiber - 0,15; acetylcellulose - 0,15; superplasticizer CHEMPLAST - 0,08; POLICEM DF - 0,15; calcium chloride - 0,69; VPK-402 - 0,08; water - 30,2. Cement compositions with other content components was prepared in the same way.

In laboratory conditions were investigated following properties of the inventive cement composition:

is the density;

- spreading;

plastic viscosity;

dynamic shear stress;

- static shear stress;

- filtrated;

the water segregation;

- terms of thickening cement mortar;

- setting time of cement material;

and investigated the following properties of the cement stone, obtained from the specified composition:

- tensile strength at break,

- tensile strength in bending;

ultimate strength in compression;

- force push-out sample.

Data about the investigated cement materials are given in table 1; data about their properties in table 2.

Table 1
Data on the content of components in cement materials
№ p/pThe components of the grouting material, wt.%
Cement Reinforcing fiberOxyethyl
cellulose
SuperplasticizerDefoamer POLICEM DFCalcium chlorideVPK-402Water
165,00,080,070,080,081,30,3332,93
268,00,100,10,330,100,40,1030,87
368,00,200,070,100,130,70,25to 30.15
466,00,330,20,250,101,031,54
566,00,250,150,200,130,10,2032,97
667,00,300,20,100,101,00,1030,2
769,00,100,180,30,100,080,0830,16
Note: 1. As the reinforcing fibers used in experiments 2, 3-polyacrylic fiber, in experiments 1, 6, 7 - polypropylene fiber, the rest of basalt fiber.
2. As superplasticizer were used in experiments 2, 4, 7. - CHEMPLAST, experience 5 - C-3, others - Melflux.

The data in table 2 show that the proposed grouting materialities required quality technological properties as composition, and cement derived from it.

The proposed material has the following advantages over known:

- increase the density of contact (force eject) 85%;

- increase the limit of compressive strength at 50%;

- increase the Flexural 27%;

- improving the strength at break of 11%.

Thanks to these properties, using the proposed backfill material in field conditions will be provided high quality construction of wells due to:

- increased the fracture toughness of cement;

- prevent the spread of cracks formed in the cement stone during the perforation in the area of high pressure;

- building a strong cementing cementing horizontal wells with small annular gaps;

- the possibility of injection and delivery of grouting material in the interval of the unit for optimal rheological characteristics;

insulation and plugging of permeable intervals due to the formation of the bridge jumpers, contributing to the rapid formation of mud cake.

Sources of information

1. USSR author's certificate No. 1006713, publ. 1983

2. RF patent №2337124, publ. 2008

Fibrearray backfill material for cementation about aktivnih intervals, subject perforation in the process of development wells, including cement, reinforcing fibers, acetylcellulose, superplasticizer CHEMPLAST MT, or-3, or Melflux, defoamer POLICEM DF, calcium chloride and water, wherein the material further comprises polydiallyldimethyl chloride VPK-402, and as a reinforcing fiber - poly (acrylic, or polypropylene, or basalt fiber in the following ratio, wt.%:

Cement66,0-69,0
Reinforcing fiber - polyacrylic,
or polypropylene, or basalt0,08-0,33
Acetylcellulose0,07-0,2
Superplasticizer CHEMPLAST, or
C-3, or Melflux0,08-0,33
Defoamer POLICEM DF0.08 to 0.13
Calcium chloride0,08-1,3
Polydiallyldimethyl chloride
VPK-402 0,08
WaterRest



 

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