Packing method supports gas wells

 

The invention relates to the oil and gas industry and can be used for the repair and insulation works (RIRs) in the gas, gas condensate and oil wells in process of drilling and operation to restore pathogenetically lining, namely cement rings. In the method of sealing lining gas wells, including the processing of cement by injection into the annulus of an aqueous solution of electrolyte - aluminum sulphate, followed by the creation of additional pressure, a specified treatment is carried out by consecutive injection of the electrolyte is sodium silicate density 1096-1265 kg/m3, the separation buffer liquid and an aqueous solution of aluminium sulphate density 1094-1333 kg/m3. The technical result from the use of the distinctive signs is to ensure penetration of the resulting silicates due to the low viscosity of the solution into the pores and cracks of the cement stone with the formation of the clogging material is silica gel and the formation of sodium aluminate directly in the reservoir, so you can restore pathogenetically cement and prevent mico the tion relates to the oil and gas industry and can be used for the repair and insulation works (RIRs) in the gas, gas condensate and oil wells in process of drilling and operation to restore pathogenetically lining, namely cement rings.

Causes of leakage (hasauthorizationto) cement sheath in the annulus space are the porosity of cement paste, as well as transverse and longitudinal cracks (slotted defects) in it.

Work on the restoration of pathogenetically cement rings to prevent and eliminate annular and annular gas shows were observed lie in the isolation of defective interval by injection under pressure of various bridging and clogging agents: cement solution, solutions of polymers and chemicals with water-and hydrocarbon-based (Serenko I. A. and others Re-cementing during the construction and operation of wells. M., Nedra, 1988, S. 110-118).

The main criterion for the selection of the type of insulation material is state of the porous medium (cement) isolated interval of the well characterized as specific injection wells during pumping of liquids and gases (m3/h MPa).

It is known that good results in high specific capacity of the well, for example 1,39 m

When the specific pickup less than 0.6 m3/h MPa before carrying out insulation measures are working to increase absorptive capacity wells: drainage, acid treatment, and others (Rules of conduct repairs in wells. RD 153.39.023-97, Krasnodar, JSC NPO Burenie. 1997).

Analysis of the work showed that the known methods and compositions for sealing lining gas wells (elimination of the leakage of the cement sheath) is not sufficiently take into account the condition of the porous medium (cement) in the annular space of the well.

As a result of the research revealed that: - for the recovery of pathogenetically intervals cement ring with a specific pickup from 0.5 to 1010-2m3/hMPa for best results, use as insulating material polymer plugging materials, and polymer p is Stanovlenie pathogenetically cement rings with specific response below 110-2m3/hMPa is applied the method of sealing lining gas wells, including the processing of cement by injection into the annulus of an aqueous solution of inorganic salt, such as a solution of aluminum sulphate, followed by the creation of additional pressure (patent RF 2166613, 7 IPC E 21 In 33/138, publ. 10.05.2001, B. I. 13); - if specific injectivity of cement in the range of10-2to 110-2m3/hMPa using the above insulating materials and solutions does not provide reliable athermalization cement stone.

Thus, the elimination of gas shows were observed in wells with a specific response in the range of 210-2to 110-2m3/hMPa remains problematic task.

There is a method of sealing columns gas wells, including the processing surface of the casing in a gas environment by injection into the annulus bridging agent water - based aqueous solution of saponified tall oil pitch with a concentration of 18 to 25 wt.% with ignoreme the postal potassium chloride water type density 1040-1190 kg/m3with the subsequent purge gas wells. (A. C. the USSR 1521860, 4 MCI E 21 In 33/138, publ. 15.11.89, B. I. 42).

The known method can be used when the specific capacity of the well water from 5110-2to 17.410-2m3/hMPa. At lower specific capacity of the well, this method cannot be used due to the large viscosity of the sealant composition.

There is also known a method for sealing columns gas wells when annular pressure, including the processing surface of the casing by serial injection into the annulus bridging agent, and an aqueous electrolyte solution with the subsequent purge gas wells, bridging agent is pre-prepared by dispersing tall oil pitch at a concentration of 20-30 wt.% in aqueous solution monoethanolamine salts of fatty acids (C21-C25) concentration of 5-7 wt.%.

Sealing leaks connection casing and cementing agent is formed by the interaction of a solution of tall oil pitch with the electrolyte. (A. C. the USSR 1737103, 5 MCI E 21 In 33/138, publ. 30.05.92, B. I. 20).

Dazeley pickup water from 210-22.510-2m3/hMPa without prior operations to increase absorptive capacity.

However, the application of the above method for sealing lining of wells, in particular for sealing a cement sheath, when the specific capacity of the well water in the range from 2.010-2to 1.010-2m3/hMPa is not possible. This is due to the small penetration depth of the insulation material in existing microcracks and pores of the cement stone in the permeable interval due to its high viscosity properties. This method can be used only after carrying out of additional works to increase the specific capacity of the well.

Closest to the claimed purpose and essential features is a method of sealing lining gas wells, including the processing of cement by injection into the annulus of an aqueous solution of electrolyte, which is used as a solution of inorganic salt is aluminum sulfate at a concentration of 9.0-23,0 wt.%, forming nerastvorimaya additional pressure, which is created not earlier than 2 h after injection of the solution. (RF patent 2166613, 7 IPC E 21 In 33/138, publ. 10.05.2001, B. I. 13 - prototype).

This method of sealing lining of wells does not provide recovery tightness in view of the fact that resulting from the interaction of aluminum sulphate with calcium hydroxide, the reaction products do not provide comparatively greater specific capacity of the well water in the range of 210-2to 110-2m3/hMPa clogging of micro-cracks and pores of the cement stone.

The claimed invention solves the problem of ensuring the integrity of the cement sheath at low specific capacity of the well water in the range of 210-2to 110-2m3/hMPa without prior operations to improve it.

This object is achieved in that in the present method of sealing lining gas wells, including the processing of cement by injection into the annulus of an aqueous solution of electrolyte - aluminum sulphate, followed by the creation of additional pressure is/m3, the separation buffer liquid and an aqueous solution of aluminium sulphate density 1094-1333 kg/m3.

The difference of the proposed method of sealing lining gas wells is that the processing of cement is carried out by sequential injection of the electrolyte is sodium silicate density 1096-1265 kg/m3, the separation buffer liquid and an aqueous solution of aluminium sulphate density 1094-1333 kg/m3.

The authors experimentally found that the injection of a solution of sodium silicate as a result of its interaction with calcium hydroxide (CA(Oh)2- the main mineral cement) are formed silicate having a low viscosity from 1510-42010-4PAwith that easily penetrates into the pores and cracks of the cement stone, which after 3-5 h into the silica.

Solutions of sodium silicate and aluminum sulphate when downloading is also easily penetrate small cracks and pores of cement paste due to their viscosity, which is close to the viscosity of the water.

The interaction of components of the electrolyte with mineral CA(Oh)2occurs in the following sequence (with Obrosova sodium in it creates an alkaline environment and a preliminary reaction to the formation of the insoluble precipitate of calcium silicate SiO3and Zola silicic acid (H2SiO3in accordance with the following equation:When pumping in the cement stone solution of aluminium sulphate in the pores of cement paste gradual transition from alkaline to acidic. In the interaction of aluminum sulphate with mineral CA(Oh)2the reaction is the formation of insoluble precipitate of calcium sulfate SO4and aluminium hydroxide Al(Oh)3in accordance with the following equation:Simultaneously on the boundary of solutions of sodium silicate and aluminum sulphate is the formation of sodium aluminate NaAlO2and as you create an acidic environment in the cement stone in the reaction takes place subsequent formation of a crystalline precipitate of hydrargillite Al2About33H2In accordance with the equation Na(OH)+Al(Oh)3-->NaAlO2+2H2O H2O+Nl2-->Na(OH)+Nalo2,
where Nalo2- aluminium hydroxide, which in alkaline medium behaves as an acid and forms during the hydrolysis hydrargillite in accordance with the equation

Zakachivanie kg/m3prevents premature mixing of sodium silicate and aluminum sulphate, avoiding the formation of sodium aluminate in the well during pumping. When this occurs a change in the density of the electrolyte.

It is this sequence of injection of fluids is important, because in the case of a primary injection of a solution of aluminium sulphate into the porous medium cement will happen its interaction with the mineral stone with the precipitation of poorly soluble salts in accordance with the equation

When the specific pickup 1010-2to 110-2m3/hMPa reliable binding environment in the case of applying a solution of aluminum sulphate is not achieved. Subsequent injection of sodium silicate solution and its interaction with the reaction products does not gelation due to the absence of acidic environment in the cement stone, which does not guarantee reliable isolation. Efficiency works to seal lining wells is much higher when you first download the sodium silicate solution and then a solution of aluminium sulphate.

Technical Reza formed silicates due to the low viscosity of the solution into the pores and cracks of the cement stone with the formation of the clogging material - silica gel and the formation of sodium aluminate directly in cement stone with subsequent precipitation of the crystalline shale sections.

Sodium silicate is a viscous liquid from light yellow to yellowish-brown in color density from 1360 to 1500 kg/m3produced according to GOST 13075-81.

Know the use of sodium silicate as a reagent used in chemical grouting - durectory way of silicatization, which in-turn injection into the ground of the two solutions is through the system of hammered metal tubes (rganizing B. A. Chemical fixation of soils in construction. M.: stroiizdat, 1986, S. 42-54).

As a result of chemical reactions between the sodium silicate solution and solutions of inorganic salts in the pores of the soil is allocated hydrogel, silicic acid, and the ground quickly and firmly attached.

It is also known the use of sodium silicate in the formulation of aluminosilicate solutions, based on the interaction of sodium silicate and sodium aluminate, which is formed silica-alumina Sol having a viscosity of 2310-43010-4PA

It should be noted that to obtain the aluminosilicate solution used to reinforce soils, you should have a sodium aluminate solution. However, it is known that solutions of sodium aluminate are unstable and after some time of them spontaneously secreted aluminium hydroxide.

The claimed technical solution in contrast to the known injected solutions of sodium silicate and aluminum sulphate react with mineral cement, and with each other. In this case the formation of sodium aluminate solution occurs in the cement stone (i.e., in situ) with subsequent precipitation of a crystalline precipitate of hydrargillite, which significantly increases the efficiency of work on the compaction of the lining wells.

In the available sources of patent and other technical and scientific information information about technical solutions that contain signs consistent with a distinctive plate conclusion on the conformity of the proposed technical solution the criterion of "inventive step".

The effectiveness of the proposed method was investigated in laboratory conditions.

EXAMPLE. The processed samples were subjected cement stone, representing a truncated cone with a height of 85 mm and a diameter of 40 mm and 45 mm with a specific pickup water from 1021010-2m3/hMPa.

For testing were prepared aqueous solutions:
a solution of aluminum sulphate density of up to 1333 1083 kg/m3;
the solution of sodium silicate density from 1086 until 1274 kg/m3.

As the separation buffer fluid used technical water density 1000 kg/m3.

Research conducted at the facility, similar to the setup described in (Danyushevsky C. S. and other reference backfill materials. M., Nedra, 1987, 275-285 C.), which allows to pump through samples of cement paste prepared solutions at various pressures by measuring their pickup.

Since the formation of aluminium hydroxide in the cement stone is a continuous process, creating additional pressure produced after 2, 6 and 20 h after the first injection of electrolyte solutions at increasing pressures.

the proposed method of sealing lining wells have a lower viscosity and, therefore, good pumpability in a porous medium with pickup from 210-2to 110-2m3/hMPa and provide pathogenetically porous medium. Insulating agent according to the method according to the prior art (patent RF 2166613) to upload the samples of cement paste under similar conditions failed.

The results of the experiments showed that:
- the greatest performance of the tested solutions according to the proposed method are the solutions of sodium silicate density 1096-1265 kg/m3and aluminum sulphate density 1094-1333 kg/m3;
- the optimum content of the buffer fluid volume percentage to a solution of sodium silicate is in the ratio from 1:10 to 1:20%.

If the amount of buffer fluid will be less necessary, for example at a ratio of 1: 50, pathogenetically cement cannot be achieved due to premature thickening of the sealing composition during injection.

If the same amount of buffer fluid will be more than necessary, for example at a ratio of 1:8, the effect of sedimentation will weaken due to the slow reaction between the components due to their significant the AET pathogenetically porous medium in a wider range pickup, namely, from 1010-2to 110-2m3/hMPa.

The injection of aqueous solutions of electrolyte (creating additional pressure can be performed repeatedly. This allows us to provide a more complete clogging of the insulated interval, i.e., better compaction of cement, and thus to ensure its reliable pathogenetically.

Application of the proposed method of sealing lining gas wells will restore pathogenetically cement and prevent annular flows in a wider range of specific pickup.


Claims

Packing method supports gas wells, including the processing of cement by injection into the annulus of an aqueous solution of electrolyte - aluminum sulphate, followed by the creation of additional pressure, characterized in that the specified treatment is carried out by consecutive injection of the electrolyte is sodium silicate density 1096-1265 kg/m3, the separation buffer liquid and an aqueous solution of aluminium sulphate density 1094-1333 kg/m3.

 

Same patents:

The invention relates to the oil industry, in particular to polymer cement compositions intended for the isolation of zones of absorption and repair and insulation works in wells

The invention relates to the oil industry, in particular, compositions for water shutoff, restore the tightness of the annular space may be used to control seepage of oil layers in workover

The invention relates to the field of oil production, in particular to methods isolation of absorbing layers in the borehole, and can be used to eliminate areas of acquisitions in the repair of production and injection wells with low formation pressure, as well as the regulation of the profile of injection wells and isolation of water production in oil wells

The invention relates to the oil and gas industry, and in particular to methods for the recovery of casing tightness
Grouting mortar // 2211304
The invention relates to the field of construction, and in particular to compositions of cement slurries used mainly when performing waterproofing-fastening work of the foundations and basements of building structures by special technology
The invention relates to the oil and gas industry, in particular to methods isolation of water production in oil and gas wells until the mounting holes the production column

The invention relates to the fastening of oil and gas wells with abnormally low, namely dry cement mixtures

The invention relates to the field of oil and gas industry and can be used for the repair and insulation works well

The invention relates to the oil and gas industry and can be used for cementing oil, gas and gas condensate wells

FIELD: oil and gas production.

SUBSTANCE: invention relates to grouting mortars used for cementing casing pipes of gas, gas-condensate, and oil wells complicated by presence of formations with low hydraulic rupture pressure as well as presence of permafrost rocks. Light-weight grouting mortar contains 47.0-60.0% special-type cement, 6.6-11.8% clinoptilite as light-weight additive, and water. As a result, casing-pipe annulus incidents during boring and running wells are avoided owing to improved parameters of grouting cement, in particular increased sedimentation stability of mortar, dimensional stability and needed strength of cement stone at low positive and negative temperature in early hardening stages are achieved at simultaneous lowering of grouting mortar density.

EFFECT: improved performance characteristics of grouting mortar.

1 tbl

FIELD: oil and gas chambers construction.

SUBSTANCE: method includes pumping of portion of water-absorbing acryl polymer, exposure of it in a well, pumping of second portion of same polymer, tempered on fresh water with concentration 1-20%, buffer of fresh water dries up, and before and after pumping of second portion of water-absorbing polymer, tempered on hydrocarbon liquid with concentration 10-20%, buffer of hydrocarbon liquid is pumped in, besides, said 2-portion systems are pumped into well multiple times.

EFFECT: higher efficiency.

1 ex

FIELD: oil and gas production.

SUBSTANCE: invention provides grouting composition intended for selective insulation of water inflows into wells, including those occurring under low-temperature and high-permeation oil reservoirs, as well as for suppressing lost-circulating zones and brine inflow zones. Composition including product of hydrolytic etherification of chlorine-containing phenyltrichlorosilane still residues with aqueous alcohol solution contains, more specifically, product obtained by hydrolytic etherification of 100 wt parts of indicated residues with 10-32,8 wt parts of 90-93% aqueous alcohol solution in presence of 10-40 wt parts of orthosilicic acid ethyl ester and, additionally, 15-35 wt parts of chlorine-containing phenyltrichlorosilane still residues at summary content of the two components 133.2-161.6 wt parts. Grouting composition may further contain up to 16.8 wt parts of polar solvent.

EFFECT: lowered repair operation cost, enabled utilization in a wide formation temperature range, including that in high-permeation and low-temperature oil reservoirs, and prolonged shelf time of grouting composition.

2 cl, 1 tbl

FIELD: oil extractive industry.

SUBSTANCE: method includes pumping, in carrying liquid - waterless mixture of oil products containing waterless oil, of powder-like water-soluble polymer and connector in amount of 0.05-0.2% for mass of carrying liquid or 30-100% for mass of power-like water-soluble polymer, as said mixture a mixture of waterless oil and light oil products processed in relation 0.1:9.9-9.9:0.1 is used, and as connector - dry aluminum nitrate, chrome nitrate, iron nitrate, magnesium nitrate, barium nitrate, calcium nitrate or their mixtures.

EFFECT: higher efficiency.

2 tbl

FIELD: oil extractive industry.

SUBSTANCE: method includes pumping, in carrying liquid - waterless mixture of oil products containing waterless oil, of powder-like water-soluble polymer and connector in amount of 0.05-0.2% for mass of carrying liquid or 30-100% for mass of power-like water-soluble polymer, as said mixture a mixture of waterless oil and light oil products processed in relation 0.1:9.9-9.9:0.1 is used, and as connector - dry aluminum acetate, chrome acetate, iron acetate, magnesium acetate, copper acetate, barium acetate, manganese acetate, calcium acetate or their mixtures.

EFFECT: higher efficiency.

1 tbl

FIELD: oil extractive industry.

SUBSTANCE: method includes pumping, in carrying liquid - waterless mixture of oil products containing waterless oil, of powder-like water-soluble polymer and connector in amount of 0.05-0.2% for mass of carrying liquid or 30-100% for mass of power-like water-soluble polymer, as said mixture a mixture of waterless oil and light oil products processed in relation 0.1:9.9-9.9:0.1 is used, and as connector - dry aluminum sulfate, chrome sulfate, iron sulfate, magnesium sulfate, copper sulfate or their mixtures, or their alums with common formula MIMIII(SO4)

.2
12H2O, where MI-Na,K,Pb,Cs,NH4, and MIII-Al,Cr,Fe,Mn.

EFFECT: higher efficiency.

2 tbl

FIELD: oil and gas extractive industry.

SUBSTANCE: method includes feeding water-isolating compound along tubing pipes, containing polyvinyl spirits and consisting of components forming an impenetrable zone in case of mixing in the bed, pressing it into bed, washing and exposure of well for forming of impenetrable zone, tubing column is lowered for 2-3 meters below perforation range, and into isolation range along tubing pipes hydro-repelling liquid is first pumped, in volume, exceeding volume of water-isolating composition in at least two times, water-isolating composition includes special liquid except from polyvinyl spirits, its pumping is performed in sequence - first goes polyvinyl spirits, then buffer liquid, special liquid, buffer liquid, repeating these operations until reaching required height of isolation interval and fixing of well-adjacent area, after that said pressing, washing of well and said polymerization exposure are performed.

EFFECT: higher efficiency.

1 dwg, 1 ex

Plugging mix // 2245989

FIELD: oil and gas production.

SUBSTANCE: plugging mix intended for cementation of oil, gas, and gas condensate wells under moderate and elevated temperatures contains 50-76% Portland cement, 20-40% finely ground quartz, and caustic magnesite powder.

EFFECT: reduced filtration and shrinkage of plugging mortar.

1 tbl

FIELD: oil and gas production.

SUBSTANCE: Portland cement-based composition contains, wt %: polymer 1-10, hardening accelerator 6-8. plasticizer 0.3-0.5, alumina cement 7-10, gypsum dihydrate and/or anhydrite 5-8, said polymer being selected from the group comprising: polyacrylamide, hydrolyzed polyacrylonitrile, polyvinyl alcohol, organosilicon liquid, latex and cationic bitumen emulsion, and said hardening accelerator being alkali or alkali-earth metal sulfates or chlorides.

EFFECT: improved properties, reduced shrinkage deformations, and under conditions resistance to fissuring.

2 cl, 2 tbl

FIELD: mining engineering, in particular improving of reservoir recovery.

SUBSTANCE: claimed composition contains (mass parts): resin 100; liquid curing agent (e.g., alkali solutions) 15.1-60; ammonium carbonate 0.1-9.9. Composition of present invention afford the ability to limit the water and sand inflow, to increase strength and permeability of formed reservoir.

EFFECT: improved reservoir recovery, increased turnaround time, reduced underground equipment in well.

2 tbl, 4 ex, 2 cl

Up!