Solid foaming agent used to remove liquid from the gas and gas condensate wells

 

(57) Abstract:

The invention relates to the technology of exploitation of gas fields and can be used to remove the reservoir fluid of gas and gas condensate wells. The invention improves the removal efficiency photoconductors with a mixture of gas condensate up to 50 vol.%, sodium salt to 8.0 wt.%, soluble salts of calcium and magnesium to 1.4 wt.% at a temperature of 80oC by obtaining solid foam prolonged action. Receive the rods of solid foaming agent by loading into the mixer 42 - 57 wt.% powdered lignosulfonate, 28 - 42 wt.% block copolymer of propylene oxide and ethylene General formula: CnH2n+1O(C3H6O)m(C2H4O)pH, where n is the number of carbon atoms in the alkyl radical of 5 to 15; m is the number of moles of propylene oxide, is 9 - 45; p - the number of moles of ethylene oxide, 30 - 180, 2 - 28 wt.% carboxymethylcellulose and 1 to 4 wt.% iron complex, monosodium salt of ethylenediaminetetraacetic acid. Carry out stirring to obtain a homogeneous mass, which is loaded into the mold. In the hole injected molded rods through the lubricator. The rods and is of troidini and can be used to remove the reservoir fluid of gas and gas condensate wells.

Known reagent for removal of fluid from downhole gas wells, which is used as block copolymers of propylene oxide and ethylene General formula:

CnH2n+1O(C3H6O)m(C2H4O)pH,

where n is the number of carbon atoms in the alkyl radical of 5 to 15;

m is the number of moles of propylene oxide, is 9 45;

p the number of moles of ethylene oxide, 30 180

(ed. St. N 1198191, 11.01.83, CL E 21 B 43/00, BI N 46, 85).

The disadvantage of this reagent is ineffective removal of mineralized vodokanalstroi mixture due to the over consumption of foaming agent, because it is impossible to ensure its long-uniform dissolution.

The block copolymers of this series are pasty substances and are used to remove fluid in the form of aqueous solutions of 10 to 20% concentration (by increasing the concentration are formed of a high-viscosity poorly pumped system), so when removing fluid together with the foaming agent to be paid a large amount of water. Moreover, in the initial time due to the increased hydration process, there is an excessive concentration of the reagent and the release of the first portions of the resulting foam, which when the acidity of the foaming agent in the upper layer of liquid leads to intense emulsification of gas condensate and the emergence of a stable emulsion due to the formation of saturated adsorption layer surfactant (reagent) on the globules of gas condensate, which slows down the process of foaming. To revive the last possible only by the introduction of additional portions of the foaming solution. In addition, obtaining a solution of the foaming agent is associated with pre-heated water up to 60 100oC, which is especially difficult in the winter.

As a prototype taken a solid foaming agent used to remove liquid from the gas and gas condensate wells specified in the method of removing fluid from downhole gas wells (ed. St. N 1710705, 4,08,89, CL E 21 B 43/00, BI N 5 92).

The finished composition contains the following components, wt.

Powder Foundation (kssb or sulfonic acid) 20 80

Surfactant-based monoalkylphenols ether of polyethylene glycol on the basis of polymetacrylate (OP-10, OP-7) 10 70

Plasticizing additive (CMC) 1 18

Facilitating additive 0,3 0,7

The composition removes vodokanalstroi with a mixture of gas condensate to about 50. and sodium salts to 1.2 wt. In this case, as shown by laboratory tests, for a core mass of 6.5 g of the dissolution rate is 24.7 g/h, the time of dissolution 18,0 min, the volume rendered fluid 455 ml, removal of the liquid 93% Photoconductive mixture at nsuta with sodium to 4.0 wt. water-soluble salts of calcium and magnesium to 0.7 wt. when 40oC is made ineffective, because the dissolution rate is 20.5 g/h, the time of dissolution 19 min, the volume of removed fluid 520 ml, removal of the liquid 63% Further increase in salinity of the reservoir fluid salts Na to 8.0 wt. water-soluble salts of Ca2+and Mg2+up to 1.4 wt. and temperatures up to 80oC does not contribute to its takeaway by using the above-mentioned foaming agent. The resulting system is poorly foamed and almost unusable.

The disadvantage of the composition of the solid foaming agent is ineffective removal of mineralized vodokanalstroi mixture at elevated temperatures. This is because when the interaction sulfonic acid ions of calcium and magnesium forms a water-insoluble calcium and magnesium salt of sulfonic acid and the activity of the sulfonic acid is reduced down to zero. In addition, in a saline environment is reduced point cloud point nonionic surfactants (the temperature at which occurs the separation of the phases and the turbidity of the solution), the resulting activity of the latter is reduced.

Specified the foaming agent has a high dissolution rate of the order of 20 to 25 g/h, which leads to the formation isbyte foam. The efficiency of the reduction process is not only due to the over consumption of foaming agent, but also by reducing the holding period (time steps of foaming agent), because the process of entering the reservoir fluid is continuous and requires frequent input of the foaming agent.

The technical result, which can be obtained by carrying out the invention is as follows: increase the removal efficiency vodokanalstroi with a mixture of gas condensate to about 50. salts sodium to 8.0 wt. soluble salts of calcium and magnesium to 1.4 wt. at a temperature of 80oC by obtaining solid foam prolonged action.

The technical result is achieved by means of known composition including powdered lignosulfonate, nonionic surfactant and carboxymethylcellulose, which further comprises an iron complex, monosodium salt of ethylenediaminetetraacetic acid, and as a nonionic surfactant block copolymers of propylene oxide and ethylene General formula:

CnH2n+1O(C3H6O)m(C2H4O)pH,

where n is the number of carbon atoms in the alkyl LASS="ptx2">

As powdered lignosulfonate use condensed sulfite-alcohol bard (kssb) TU 39-095-75, sulfite-yeast mash (RRT) TU 81-04-225 TV, lignosulfonates brand T OST 13-183-83. The action of these reagents in the composition of the foaming agent equivalent. Carboxymethylcellulose (CMC) use THE 6-55-39-90, 6-55-40-90.

Block copolymers of propylene oxide and ethylene are pasty substances developed by VNIIPV known by the author. St. N 1198191, 11.01.83, CL E 21 In 43/00. Iron complex monosodium salt ethylendiaminetetraacetic acid (complexant iron), powdery substance use on THE 6-09-2391-77.

In Fig. 1 shows the structural formula. According to available sources known not identified the use of the iron complex, monosodium salt ethylendiaminetetraacetic acid or in a mixture with other reagents objectives (expected effect). Known application in order to remove fluid from downhole gas wells block copolymers of propylene oxide and ethylene (ed.St. N 1198191, 11.01.83, CL E 21 B 43/00), as well as mixtures thereof with ethylene glycol or diethylene glycol and water (ed. C. N 1164402, 1.04.83, CL E 21 B 43/00).

The compositions inoob the iron complex, monosodium salt of ethylenediaminetetraacetic acid was not detected.

The content in the solid foaming agent of complexant iron, easily change the degree of oxidation, contributes to the occurrence of a number of redox processes linking the ingredients in the solid complex. The cations of iron to catalyze the formation of radicals of high molecular compounds and ligands ethylenediaminetetraacetic acid accelerate their catalytic effect.

In Fig. 2 is a schematic representation of the processes feast oxidation of high-molecular compounds (CMC, lignosulfonate, block copolymers), ROOH, R-H and R-OH molecule CMC, lignosulfonate and block copolymers;

edta ethylenediaminetetraacetic acid.

In Fig. 3 circuit equations and mixing of molecules CMC, lignosulfonate and block copolymers formed by the radicals.

In Fig. 4 scheme of the equations of suture CMC, lignosulfonate and block copolymers formed by the radicals.

In Fig. 4 scheme (part of the structure) formed covalent saltlike compounds molecules of lignosulfonate and CMC with Fe2+. Ferrous ions formed as a result of redox processes is partially leads to the formation of covalent saltlike compounds.

In Fig. 5 scheme of the resulting complex block copolymers with cations of Fe3+member of complexant iron, and Fe2+included in the covalent saltlike compounds. The complex formed by coordination of the cations, hydroxyl and ester groups. In the result of the combined effect of all factors formed a solid system with a high density of cohesion.

The initial stage of the dissolution of any polymer frame is the hydration of the hydrophilic groups of the macromolecules, therefore, the dissolution largely depends on the uniformity of distribution of such groups as: SO23+,, COO-C2H4O-and so on For these groups is the interaction of the components of the foaming agent and the formation of large polymer particles, the energy of which is higher than the binding energy of hydrophilic groups with water. Due to the size increase of the polymer units, and also due to the partial shielding of hydrocarbon radicals hydrophilic groups, the dissolution of the foaming agent is very slow, and therefore, slowly released the block copolymer, which allows to maintain the concentration of the foaming agent on the level of crit is tx2">

The activity of the foaming agent is not reduced in the saline environment, because complexes are formed with ions of calcium and magnesium. These complexes adsorbed on the phase boundary, form strong adsorption of the surfactant layer. In addition, in education for the past attended the lignosulfonate complexes and CMC, which not only strengthens the adsorption layer of emulsifier, but also reduces the amount of block copolymer and thereby increases the carrying capacity of the foaming agent.

In the presence of condensate in the reservoir fluid passing ability of any foaming agent is reduced, because part of the foaming agent is spent on emulsification of gas condensate. It is known that a mandatory condition for removal of the condensate is the formation of hydrophilic emulsion (dispersion medium aqueous solution), because the hydrophobic emulsion, dispersion medium which is a gas that inhibits the foaming system. On hydrophobic emulsion influence of salts mineralization pronounced: at low concentrations of the electrolytes emulsion stability increases when high is emulgirovannie. The hydrophilic emulsion influence of electrolyte expressed weakly. Type formed emulsion hydrophiloidea.

The temperature increase in the range up to the cloud point increases the rate of dissolution of the solid foaming agent, but simultaneously increases the intensity of foaming, which increases carrying capacity.

P R I m e R 1. Loaded into the mixer 2,73 g (42 wt.) Kssb, 1,82 g (28 wt.) block copolymer, 1,82 g (28 wt.) CMC and 0.13 g (2 wt.) complexant iron. Carry out stirring to obtain a homogeneous mass, which is loaded into the mold. Molded rod of solid foam weighs 6.5 g and has the following options: l 50 mm, 11 mm, the Efficiency of removal of produced water evaluate the results of laboratory studies on the plant, which is a glass tube with a length of 2.3 m and a diameter of 0,032 m, through the lower part of which is passed through rotameter air with a flow rate of 33 cm3/s and analyzed fluid (photocontest mixture containing about 50. gas condensate), with mineralization: NaCl 8 wt. CaCl20.7 wt. MgCl20.7 wt. Liquid thermostatic at 80oC.

The rate of dissolution of the foaming agent is 0.85 g/h, the time of dissolution 457 min, the volume rendered fluid 1560 ml, removal of the liquid 100% or 0.24 m3/kg.

P R I m m e R 2. D IS (55)

The block copolymer 2,73 (42)

CMC 0,13 (2)

Complexant iron 0.06 (1)

and conduct all operations as described in example 1.

The rate of dissolution of the foaming agent is 1.13 g/h, the time of dissolution 346 min, the volume rendered fluid 1625 ml, removal of the liquid 100% or 0.25 m3/kg.

P R I m e R 3. To obtain a rod of solid foaming agent by weight of 6.5 g take the following components, g (wt.):

Technical lignosulfonates brand T 3,25 (50)

The block copolymer 2,14 (33)

CMC 0,85 (13)

Complexant iron 0,26 (4)

and conduct all operations as described in example 1.

The rate of dissolution of the foaming agent to 0.67 g/h, the time of dissolution 580 min, the volume rendered fluid 1885 ml, removal of the liquid 100% or 0.29 m3/kg.

P R I m e R 4. To obtain a rod of solid foaming agent by weight of 6.5 g take the following components, g (wt.):

RRT IS 3.7 (57)

The block copolymer 2,47 (38)

CMC 0,26 (4)

Complexant iron 0,07 (1)

and conduct all operations as described in example 1.

The rate of dissolution of the foaming agent 1.48 g/h, the time of dissolution 263 min, the volume rendered fluid 1433 ml, removal of fluid 96% or 0.22 m3/kg.

P R I m e R 5. For po)

The block copolymer of 1.75 (27)

CMC 1,89 (29)

Complexant iron 0,03 (0,5)

and conduct all operations as described in example 1, but the temperature control fluid is carried out at 60oC.

The rate of dissolution of the foaming agent is 0,80 g/h, the time of dissolution 510 min, the volume of delivered liquid 650 ml, removal of the liquid 80% or 0.10 m3/kg.

P R I m e R 6. To obtain a rod of solid foaming agent by weight of 6.5 g take the following components, g (wt.):

Technical lignosulfonates brand T 2,73 (42)

The block copolymer of 2.8 (43)

CMC 0,65 (10)

Complexant iron 0,32 (5)

and conduct all operations as described in example 1, and the temperature of the liquid in example 5.

The rate of dissolution of the foaming agent is 0.70 g/h, the time of dissolution 590 min, the volume rendered fluid 1885 ml, removal of the liquid 100% or 0.29 m3/kg.

P R I m e R 7. To obtain a rod of solid foaming agent by weight of 6.5 g take the following components, g (wt.):

KSSB OF 3.77 (58)

The block copolymer of 2,6 (40)

CMC 0,065 (1)

Complexant iron 0,065 (1)

and conduct all operations as described in example 1, and the temperature of the liquid in example 5.

The speed of restorani 88% or 0,13 m3/kg.

P R I m e R 8. To obtain a rod of solid foaming agent by weight of 6.5 g take the following components, g (wt.):

RRT 2,66 (41)

The block copolymer 1,95 (30)

CMC 1,82 (29)

Complexant iron 0,07 (1)

and conduct all operations as described in example 1, and the temperature of the liquid in example 5. The rate of dissolution of the foaming agent is 1.3 g/h, the time of the dissolution of 300 rpm, the volume of delivered liquid 1365 ml, removal of the liquid 98% or 0.21 m3/kg.

The content of complexant iron in amounts less than 1 wt. and the block copolymer in amounts of less than 28 wt. it is impractical, because of sharply reduced carrying capacity of the foaming agent.

The content of complexant iron more than 4 wt. and the block copolymer in the amount of more than 42 wt. not economically viable, because the carrying capacity of the foaming agent is almost not increased.

The content of the powdered lignosulfonate in an amount of less than 42 wt. and CMC in the amount less than 2 wt. it is impractical, because these quantities of reagents is not enough to create uniform (solid) polymer frame, thus reducing carrying capacity, and the rod has a low strength and plasti because badly formed rods.

The content of the CMC in more than 28 wt. it is impractical, because the background of a slight increase in the strength of the rod decreases the proportion of the active component.

The proposed composition of the solid foaming agent is easy to use in winter conditions (liquid foam has to warm up). Solid foaming agent can be introduced into the well through the lubricator, while for pumping liquid foam requires special equipment.

The rods in the inventive composition have a density of about 1000 1030 kg/m3so when barbotirovat air in the borehole will be some time on the surface of the reservoir fluid, contributing to uniform dissolution of complex ingredients and removal of fluid.

The composition of the solid foaming agent prototype relatively healthy (removal of fluid 63%) in the absence of condensate, when the salinity of the reservoir water of salts of sodium 4 wt. chlorides of calcium and magnesium to 0.7 wt. (sum). In similar conditions the rate of dissolution of the rods made by the present composition is reduced to 15 to 30 times the percentage of removal of the fluid increases 1.5 times. Further Crabb. and in the presence of salinity on water-soluble salts of Ca2+and Mg2+up to 1.4 wt. (sum) or 0.7 wt. (amount), respectively, under conditions of a temperature of 40 80oC, a known foaming agent unworkable.

Solid Converter to remove liquid from gas and gas condensate wells containing powdered lignosulfonate, nonionic surface-active agent and carboxymethyl cellulose, characterized in that it further comprises an iron complex, monosodium salt of ethylenediaminetetraacetic acid, and as a nonionic surfactant block copolymers of propylene oxide and ethylene General formula

CnH2n+1O(C3H6O)m(C2H4O)pH,

where n 5-14 number of carbon atoms in the alkyl radical;

m 9-45 the number of moles of propylene oxide;

p 30-180-the number of moles of ethylene oxide,

in the following ratio of components in the finished foam, dry wt.

Powdered lignosulfonate 42 57

Block copolymers of propylene oxide and ethylene 28 42

Carboxymethylcellulose 2 28

Iron complex, monosodium salt of ethylenediaminetetraacetic acid - 1 4.

 

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