CA2710986A1 - Magnetic polymer pellets and a method of generating the blocking gel plug - Google Patents
Magnetic polymer pellets and a method of generating the blocking gel plug Download PDFInfo
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- CA2710986A1 CA2710986A1 CA2710986A CA2710986A CA2710986A1 CA 2710986 A1 CA2710986 A1 CA 2710986A1 CA 2710986 A CA2710986 A CA 2710986A CA 2710986 A CA2710986 A CA 2710986A CA 2710986 A1 CA2710986 A1 CA 2710986A1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
- B29B9/00—Making granules
- B29B9/12—Making granules characterised by structure or composition
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
- C08J3/02—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques
- C08J3/03—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in aqueous media
- C08J3/075—Macromolecular gels
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
- C08J3/12—Powdering or granulating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
- B29K2105/0005—Condition, form or state of moulded material or of the material to be shaped containing compounding ingredients
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
- B29K2995/0003—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular electrical or magnetic properties, e.g. piezoelectric
- B29K2995/0008—Magnetic or paramagnetic
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2305/00—Characterised by the use of polysaccharides or of their derivatives not provided for in groups C08J2301/00 or C08J2303/00
- C08J2305/04—Alginic acid; Derivatives thereof
Abstract
The invention is related to magnetic polymer pellets represented as polymer matrix and solid filler as well as to their application for gel plugs' formation. As per the invention the polymer pellet is represented as gel matrix from anionic polymer cross-linked with cations of multivalent metals in which ferromagnetic micro-particles are dispersed with the ratio of the ferromagnetic micro-particles and anionic polymer concentrations from 0.5 to 5. The locking gel plug formation method provides the delivery of polymer pellets to the gel plug formation zone and the locking gel plug is formed due to the ambient medium pH increase to pH > 7 in the confined volume where they are retained by the external magnetic field.
Description
MAGNETIC POLYMER PELLETS AND A METHOD OF GENERATING
THE BLOCKING GEL PLUG
This invention is related to magnetic polymer pellets represented as a polymer matrix and solid filler as well as to the application thereof for making gel plugs.
Polymer (alginate) pellets with para- and ferromagnetic properties and mathods to obtain them are described in scientific literature. They are gels crosslilnked with calcium (Lee, D.Y. et al., Ieee Transactions on Magnetics 2004, 40, 2961; Roger, S. et al., Journal of Magnetism and Magnetic Materials 2006, 305, 221) or iron ions (Llanes, F. et al., International Journal of Biological Macromolecules 2000, 27, 35; Nishio, Y. et al., Polymer 2004, 45, 7129; Naik, R. et al., Journal of Applied Physics 2005, 97, ), and containing magnetic substance or particles: barium ferrite (Lee, D.Y. et al., Ieee Transactions on Magnetics 2004, 40, 2961), iron oxide (Llanes, F. et al., International Journal of Biological Macromolecules 2000, 27, 35; Nishio, Y. et al., Polymer 2004, 45, 7129; Naik, R. et al., Journal of Applied Physics 2005, 97, ) and magnetic iron (Tyagi, R. et al., Biocatalysis and Biotransformation 1995) 12, 293; Roger, S. et al., Journal of Magnetism and Magnetic Materials 2006, 305, 221).
The procedure to obtain magnetic alginate pellets includes introduction of crosslinking ions into the mixture of sodium alginate solution and ferrofluid.
Different introduction options have been described: "internal" and "external".
As applied to calcium-alginate gels the "external" method makes use of the instillation of the sodium alginate and ferrofluid mixture into the calcium chloride solution (Lee, D.Y. et al., Ieee Transactions on Magnetics 2004, 40, 2961; Roger, S. et al., Journal of Magnetism and Magnetic Materials 2006, 305, 221). In the "internal" method, first "inactive" calcium as complex with EDTA
is added to the mixture of sodium alginate and ferrofluid mixture and then the calcium is slowly released by the medium acidification using gluco-6-lactone I
hydrolysis (Roger, S. et al., Journal of Magnetism and Magnetic Materials 2006, 305, 221). With iron-alginate gels "internal" administration method is applied which is based on alkaline oxidation of ferrous iron in calcium alginate solution (Llanes, F. et al., International Journal of Biological Macromolecules 2000, 27, 35). It was demonstrated that in "internal" method of administering the crosslinking ions more homogenous particles are obtained.
The use of magnetic alginate pellets for biological separation and treatment of enzymes and cells in the magnetic field has also been described (Tyagi, R. et al., Biocatalysis and Biotransformation 1995, 12, 293; Ames, T.T.
et al., Biotechnology Progress 1997, 13, 336; Liu, C.Z. et al., Journal of Bioscience and Bioengineering 2000, 89, 420), for effluents treatment of heavy metals (Nestle, N. et al., Colloids and Surfaces A-Physicochemical and Engineering Aspects 1996, 115, 141; Ngomsik, A.F. et al., Water Research 2006, 40, 1848).
Thus, U.S. Patent No. 4,652,257 describes the method of obtaining manetically localized polymerizing lipidic vesicles, containing the target substance (medicine), and the method of the vesicles' destruction and release of the contents thereof under the magnetic field effect. The therapeutic substance and ferromagnetic particles are encapsulated in the lipidic vesicle, generated by the polymerizing lipids. The lipids are polymerized under the effect of ultraviolet radiation with the formation of the membrane resistant to chemical and physical effects. Any ferromagnetic substance, preferably single-domain magnets of bacterial origin, magentites, ferrites or fine-grain iron sawdust may be used as magnetic particles. The vesicles are delivered to the target organ under the effect of the external constant magnetic field. After localization in the proper location the vesicle membrane is destroyed or destabilized due to the application of the variable magnetic field. Frequency and duration of the variable magnetic field action determine the rate of the vesicle-encapsulated therapeutic substance release.
THE BLOCKING GEL PLUG
This invention is related to magnetic polymer pellets represented as a polymer matrix and solid filler as well as to the application thereof for making gel plugs.
Polymer (alginate) pellets with para- and ferromagnetic properties and mathods to obtain them are described in scientific literature. They are gels crosslilnked with calcium (Lee, D.Y. et al., Ieee Transactions on Magnetics 2004, 40, 2961; Roger, S. et al., Journal of Magnetism and Magnetic Materials 2006, 305, 221) or iron ions (Llanes, F. et al., International Journal of Biological Macromolecules 2000, 27, 35; Nishio, Y. et al., Polymer 2004, 45, 7129; Naik, R. et al., Journal of Applied Physics 2005, 97, ), and containing magnetic substance or particles: barium ferrite (Lee, D.Y. et al., Ieee Transactions on Magnetics 2004, 40, 2961), iron oxide (Llanes, F. et al., International Journal of Biological Macromolecules 2000, 27, 35; Nishio, Y. et al., Polymer 2004, 45, 7129; Naik, R. et al., Journal of Applied Physics 2005, 97, ) and magnetic iron (Tyagi, R. et al., Biocatalysis and Biotransformation 1995) 12, 293; Roger, S. et al., Journal of Magnetism and Magnetic Materials 2006, 305, 221).
The procedure to obtain magnetic alginate pellets includes introduction of crosslinking ions into the mixture of sodium alginate solution and ferrofluid.
Different introduction options have been described: "internal" and "external".
As applied to calcium-alginate gels the "external" method makes use of the instillation of the sodium alginate and ferrofluid mixture into the calcium chloride solution (Lee, D.Y. et al., Ieee Transactions on Magnetics 2004, 40, 2961; Roger, S. et al., Journal of Magnetism and Magnetic Materials 2006, 305, 221). In the "internal" method, first "inactive" calcium as complex with EDTA
is added to the mixture of sodium alginate and ferrofluid mixture and then the calcium is slowly released by the medium acidification using gluco-6-lactone I
hydrolysis (Roger, S. et al., Journal of Magnetism and Magnetic Materials 2006, 305, 221). With iron-alginate gels "internal" administration method is applied which is based on alkaline oxidation of ferrous iron in calcium alginate solution (Llanes, F. et al., International Journal of Biological Macromolecules 2000, 27, 35). It was demonstrated that in "internal" method of administering the crosslinking ions more homogenous particles are obtained.
The use of magnetic alginate pellets for biological separation and treatment of enzymes and cells in the magnetic field has also been described (Tyagi, R. et al., Biocatalysis and Biotransformation 1995, 12, 293; Ames, T.T.
et al., Biotechnology Progress 1997, 13, 336; Liu, C.Z. et al., Journal of Bioscience and Bioengineering 2000, 89, 420), for effluents treatment of heavy metals (Nestle, N. et al., Colloids and Surfaces A-Physicochemical and Engineering Aspects 1996, 115, 141; Ngomsik, A.F. et al., Water Research 2006, 40, 1848).
Thus, U.S. Patent No. 4,652,257 describes the method of obtaining manetically localized polymerizing lipidic vesicles, containing the target substance (medicine), and the method of the vesicles' destruction and release of the contents thereof under the magnetic field effect. The therapeutic substance and ferromagnetic particles are encapsulated in the lipidic vesicle, generated by the polymerizing lipids. The lipids are polymerized under the effect of ultraviolet radiation with the formation of the membrane resistant to chemical and physical effects. Any ferromagnetic substance, preferably single-domain magnets of bacterial origin, magentites, ferrites or fine-grain iron sawdust may be used as magnetic particles. The vesicles are delivered to the target organ under the effect of the external constant magnetic field. After localization in the proper location the vesicle membrane is destroyed or destabilized due to the application of the variable magnetic field. Frequency and duration of the variable magnetic field action determine the rate of the vesicle-encapsulated therapeutic substance release.
U.S. Patent No. 5,019,372 proposes a method of obtaining solid polymer pellets filled with stainless steel particles and containing the target biologically active substance (water-soluble medicine), the release of which is accelerated in the variable magnetic field. The polymer pellet is made of bio-compatible plastic material non-soluble in the application field, e.g., of ethylene-vinyl acetate copolymer. The biologically active substance and magnetic particles are dispersed in the monomers methylene chloride solution, after which polymerization and pelletization are conducted. The pellets are places in the aqueous medium where the target substance is released effected by the oscillating magnetic field with the intensity of 0.5 to 1,000 Gauss. The rate of the release stimulated by the magnetic field is by factor 30 higher than without this stimulation and amounts to about 400 micro-Gauss per hour. A water-soluble substance with the molecular weight exceeding 150 D may be used as the target substance.
In the proceeding Z. Lu et al. (Langmuir, 2005, 21, 2042-2050) a method of obtaining magnetically sensitive polyelectrolyte multi-layer micro-pellets was proposed. The capsule membrane consists of several layers formed by sodium phosphonated polystyrene and polyallylamine hydrochloride with a layer of cobalt nano-particles coated with gold between them. The capsule membrane permeability for dextrane marked with a fluorescent tag was researched. It was demonstrated that the variable magnetic field with the frequency of 100-300 Hz and intensity of 1200 Gauss causes intensive rotation of the cobalt nano-particles which significantly damages the capsule membrane integrity. The optimum magnetic sensitivity of the membrane sensitivity was observed in the capsules with the walls formed of 10 layers of polyelectrolytes and 1 layer of ferromagnetic nano-particles.
The polymer pellets described are designed for bio-medical application in the systems of targeted transport of medicines. Their application in other technologies is limited by the process complexity and their high cost.
In the proceeding Z. Lu et al. (Langmuir, 2005, 21, 2042-2050) a method of obtaining magnetically sensitive polyelectrolyte multi-layer micro-pellets was proposed. The capsule membrane consists of several layers formed by sodium phosphonated polystyrene and polyallylamine hydrochloride with a layer of cobalt nano-particles coated with gold between them. The capsule membrane permeability for dextrane marked with a fluorescent tag was researched. It was demonstrated that the variable magnetic field with the frequency of 100-300 Hz and intensity of 1200 Gauss causes intensive rotation of the cobalt nano-particles which significantly damages the capsule membrane integrity. The optimum magnetic sensitivity of the membrane sensitivity was observed in the capsules with the walls formed of 10 layers of polyelectrolytes and 1 layer of ferromagnetic nano-particles.
The polymer pellets described are designed for bio-medical application in the systems of targeted transport of medicines. Their application in other technologies is limited by the process complexity and their high cost.
The use of polymers for controlled generation of the plug for zone insulation is described in Patent RU 2276675. The invention describes the method of forming a gel plug by gellation of the fluid containing hydrophobically associating substances and water-soluble gellation inhibitor.
In case of contact between the fluid and hydrocarbons the inhibitor retains its properties whereas in case the fluid's contact with the water medium the inhibitor is dissolved which results in gellation. Therefore, the method enables monitoring water influxes in the oil-producing wells by gel plugs' formation.
However, this method has its disadvantages: 1) gellation with the use of this fluid is irreversible and starts from the first contact with water which could occur on the surface which creates significant difficulties during the injection of water into the well, 2) the already formed gel plugs in certain conditions may also lock oil-bearing formations making hydrocarbons' production more difficult.
The invention claimed covers polymer pellets containing ferromagnetic microparticles and having optimum mechanical properties enabling gel plug formation resulting from their swelling in the external magnetic field. The polymer granules may be used when zone insulation is required. Influenced by the magnetic field these pellets migrate to the location where zone insulation is required and are destroyed due to swelling in the confined volume where they are held by the magnetic field and form the gel plug.
As per this invention, the polymer pellet is a gel matrix of anionic polymer cross-linked with cations of multivalent metals in which ferromagnetic particles are dispersed at the concentration of ferromagnetic micro-particles of 0.5 - 5%. The concentration of ferromagnetic particles below 0.5% does not provide the particles' required ferromagnetic properties whereas the particles' concentration of >5% results in heavier pellets which swell worse. Anionic polysaccharide with the concentration from 0.1 to 2% is used as the anionic polymer. The anionic polysaccharide may be sodium alginate, pectin with etherification degree of maximum 30%, carboxymethyl cellulose or oxyethylcarboxymethyl cellulose. As the ferromagnetic particles spherical or bar-shaped particles of iron or oxides thereof with the minimum size of 40 -300 nm, e.g., magnetite or magenite are used.
As per this invention, the polymer pellets are used to form the locking gel plug, e.g., to provide the formation insulation. In accordance with the invention, the method of making the locking gel plug includes delivery of the gellating compound made as polymer pellets to the gel plug formation zone; each pellet being a gel matrix of anion polymer cross-linked with the cations of multivalent metals in which ferromagnetic particles are dispersed with the ferromagnetic particles' concentration from 0.5 to 5%. The locking gel plug is formed due to the pellets' intensive swelling provided by the ambient pH increase to pH>7 in the confined volume where they are retained by the external magnetic field with the intensity of 5,000-20,000 Oersted.
The polymer pellets may be pre-dried. The humidity of the dried pellets is 15-25%. A substance stimulating the polymer pellets' swelling may be added to the medium in which the pellets are swelled; as this substance soda as well as phosphates, polyphosphates, citrates or chelating agents like ethylenediaminotetraacetic acid (EDTA) sodium salt. To speed up the swelling the pellets' surface may be pre-wetted with ethyl alcohol. To intensify the swelling of the pellets cross-linked with barium ions their surface is treated with 0.1 M hydrochloric acid. The pellets may be delivered by the application of the external magnetic field providing the polymer pellets' migration to the gel plug formation zone.
As per this invention, the polymer pellets may be obtained by dispersing ferromagnetic particles stirred in the water solution of anionic polysaccharide capable of ionotropic gellation, after that the suspension is dripped into the multivalent metal salt water solution. As the multivalent metal salts water-soluble salts of calcium, barium or aluminum may be used.
The essence of the invention may be illustrated by the following non-limiting examples.
Example 1 Making Magnetite-Containing Alginate Pellets 0.3 g of magnetite (powder of irregular shape Fe304 particles with the size of about 300 nm) is dispersed by stirring in 9.7 g of 1.4 %-solution of sodium alginate in 0.01 M solution of the buffer mixture tris-(hydroxymethyl)-aminomethane - HCl with pH 7.4. The sodium alginate solution magnetite suspension obtained is dripped into 100 ml of 3 % solution of calcium chloride in the buffer mixture tris-(hydroxymethyl)-aminomethane - HCl above at pH
7.4. Simultaneously calcium alginate pellets with the diameter of 3 mm are formed. The pellets' suspension is kept at 4 C for 24 hours and then washed five times with 20 ml of bidistilled water and stored in the refrigerator for further use or dried using any method until the residual humidity is 15-25%.
Example 2 MakingMagenite-Containing Alginate Pellets 0.3 g of magenite (powder of needle-shaped y-Fe203 particles with the diameter of 40-60 nm and length of 400-800 nm) is dispersed by stirring in 9.7 g of 1.4 % solution of sodium alginate in 0.01 M solution of the buffer mixture tris-(hydroxymethyl)-aminomethane - HCl with pH 7.4. The sodium alginate solution magenite suspension obtained is dripped into 100 ml of 3 % solution of calcium chloride in the buffer mixture tris-(hydroxymethyl)-aminomethane -HCl above at pH 7.4. The suspension of the pellets (diameter 3 mm) formed is kept at 4 C for 24 hours and then washed five times with 20 ml of bidistilled water and stored in the refrigerator for further use.
Example 3 Gel Plug Formation Dried alginate pellets containing ferromagnetic particles are introduced into the system with the capillaries with the diameter of 2-6 mm and fluid circulating with the rate of max. 700 ml/min. Under the influence of the magnetic field with the intensity of 7,000-10,000 Oersted the pellets are localized in the magnet area swell with the gel plug. The pressure in the capillaries is increased to 250 kPa using compressed gas. The pressure formed withstands the pressure.
Example 4 Drying of Alginate Pellets Containing Magnetite at Room Temperature The magnetic pellets made as shown in Example 1 are dried at the room temperature for 24 hours. Hereby the average weight of one pellet is reduced from 12.8 to 1.1 micrograms within the first 3 hours and then virtually does not change. The pellets retain spherical shape. Weight reduction during the drying is accompanied by the diameter reduction from 3.1 mm to 0.7-0.9 mm.
Example 5 Drying of Alginate Pellets Containing Magnetite at 80 C
The magnetic pellets made as shown in Example 1 are dried at 80 C B for 1 hour. Hereby the average weight of one pellet is reduced from 12.8 to 1.1 micrograms within the first 0.5 hours and then virtually does not change. The pellets retain spherical shape. Weight reduction during the drying is accompanied by the diameter reduction from 3.1 mm to 0.7-0.9 mm.
Example 6 Drying of Alginate Pellets Containing Magnetite using Sublimation Dehydration Method The magnetic pellets made as shown in Example 1 are frozen at -50 C
and then dried in the sublimation dehydration unit at the residual pressure of 1.1 Pa (Martin Chrict model ALFA 1-2 LD; Osterode am Harz, W, Germany) for 14 hours. Hereby the average weight of one pellet is reduced from 12.8 to 1.1 micrograms within the first 5 hours and then virtually does not change. The weight loss during the drying is accompanied by the pellets' shape change, they become disc-shaped (diameter 2.4 mm and thickness 0.25 mm).
Example 7 Drying of Alginate Pellets Containing Magnetite at Room Temperature in Vacuum The magnetic pellets made as shown in Example 1 are dried at the room temperature in vacuum (1-10-3 mm Hg) for 22 hours. Hereby the average weight of one pellet is reduced from 12.8 to 1.1 micrograms within the first 5 hours and then virtually does not change. The pellets retain spherical shape.
The weight loss during the drying is accompanied by the pellets' diameter reduction from 3.1 mm to 0.9-1.0 mm.
In case of contact between the fluid and hydrocarbons the inhibitor retains its properties whereas in case the fluid's contact with the water medium the inhibitor is dissolved which results in gellation. Therefore, the method enables monitoring water influxes in the oil-producing wells by gel plugs' formation.
However, this method has its disadvantages: 1) gellation with the use of this fluid is irreversible and starts from the first contact with water which could occur on the surface which creates significant difficulties during the injection of water into the well, 2) the already formed gel plugs in certain conditions may also lock oil-bearing formations making hydrocarbons' production more difficult.
The invention claimed covers polymer pellets containing ferromagnetic microparticles and having optimum mechanical properties enabling gel plug formation resulting from their swelling in the external magnetic field. The polymer granules may be used when zone insulation is required. Influenced by the magnetic field these pellets migrate to the location where zone insulation is required and are destroyed due to swelling in the confined volume where they are held by the magnetic field and form the gel plug.
As per this invention, the polymer pellet is a gel matrix of anionic polymer cross-linked with cations of multivalent metals in which ferromagnetic particles are dispersed at the concentration of ferromagnetic micro-particles of 0.5 - 5%. The concentration of ferromagnetic particles below 0.5% does not provide the particles' required ferromagnetic properties whereas the particles' concentration of >5% results in heavier pellets which swell worse. Anionic polysaccharide with the concentration from 0.1 to 2% is used as the anionic polymer. The anionic polysaccharide may be sodium alginate, pectin with etherification degree of maximum 30%, carboxymethyl cellulose or oxyethylcarboxymethyl cellulose. As the ferromagnetic particles spherical or bar-shaped particles of iron or oxides thereof with the minimum size of 40 -300 nm, e.g., magnetite or magenite are used.
As per this invention, the polymer pellets are used to form the locking gel plug, e.g., to provide the formation insulation. In accordance with the invention, the method of making the locking gel plug includes delivery of the gellating compound made as polymer pellets to the gel plug formation zone; each pellet being a gel matrix of anion polymer cross-linked with the cations of multivalent metals in which ferromagnetic particles are dispersed with the ferromagnetic particles' concentration from 0.5 to 5%. The locking gel plug is formed due to the pellets' intensive swelling provided by the ambient pH increase to pH>7 in the confined volume where they are retained by the external magnetic field with the intensity of 5,000-20,000 Oersted.
The polymer pellets may be pre-dried. The humidity of the dried pellets is 15-25%. A substance stimulating the polymer pellets' swelling may be added to the medium in which the pellets are swelled; as this substance soda as well as phosphates, polyphosphates, citrates or chelating agents like ethylenediaminotetraacetic acid (EDTA) sodium salt. To speed up the swelling the pellets' surface may be pre-wetted with ethyl alcohol. To intensify the swelling of the pellets cross-linked with barium ions their surface is treated with 0.1 M hydrochloric acid. The pellets may be delivered by the application of the external magnetic field providing the polymer pellets' migration to the gel plug formation zone.
As per this invention, the polymer pellets may be obtained by dispersing ferromagnetic particles stirred in the water solution of anionic polysaccharide capable of ionotropic gellation, after that the suspension is dripped into the multivalent metal salt water solution. As the multivalent metal salts water-soluble salts of calcium, barium or aluminum may be used.
The essence of the invention may be illustrated by the following non-limiting examples.
Example 1 Making Magnetite-Containing Alginate Pellets 0.3 g of magnetite (powder of irregular shape Fe304 particles with the size of about 300 nm) is dispersed by stirring in 9.7 g of 1.4 %-solution of sodium alginate in 0.01 M solution of the buffer mixture tris-(hydroxymethyl)-aminomethane - HCl with pH 7.4. The sodium alginate solution magnetite suspension obtained is dripped into 100 ml of 3 % solution of calcium chloride in the buffer mixture tris-(hydroxymethyl)-aminomethane - HCl above at pH
7.4. Simultaneously calcium alginate pellets with the diameter of 3 mm are formed. The pellets' suspension is kept at 4 C for 24 hours and then washed five times with 20 ml of bidistilled water and stored in the refrigerator for further use or dried using any method until the residual humidity is 15-25%.
Example 2 MakingMagenite-Containing Alginate Pellets 0.3 g of magenite (powder of needle-shaped y-Fe203 particles with the diameter of 40-60 nm and length of 400-800 nm) is dispersed by stirring in 9.7 g of 1.4 % solution of sodium alginate in 0.01 M solution of the buffer mixture tris-(hydroxymethyl)-aminomethane - HCl with pH 7.4. The sodium alginate solution magenite suspension obtained is dripped into 100 ml of 3 % solution of calcium chloride in the buffer mixture tris-(hydroxymethyl)-aminomethane -HCl above at pH 7.4. The suspension of the pellets (diameter 3 mm) formed is kept at 4 C for 24 hours and then washed five times with 20 ml of bidistilled water and stored in the refrigerator for further use.
Example 3 Gel Plug Formation Dried alginate pellets containing ferromagnetic particles are introduced into the system with the capillaries with the diameter of 2-6 mm and fluid circulating with the rate of max. 700 ml/min. Under the influence of the magnetic field with the intensity of 7,000-10,000 Oersted the pellets are localized in the magnet area swell with the gel plug. The pressure in the capillaries is increased to 250 kPa using compressed gas. The pressure formed withstands the pressure.
Example 4 Drying of Alginate Pellets Containing Magnetite at Room Temperature The magnetic pellets made as shown in Example 1 are dried at the room temperature for 24 hours. Hereby the average weight of one pellet is reduced from 12.8 to 1.1 micrograms within the first 3 hours and then virtually does not change. The pellets retain spherical shape. Weight reduction during the drying is accompanied by the diameter reduction from 3.1 mm to 0.7-0.9 mm.
Example 5 Drying of Alginate Pellets Containing Magnetite at 80 C
The magnetic pellets made as shown in Example 1 are dried at 80 C B for 1 hour. Hereby the average weight of one pellet is reduced from 12.8 to 1.1 micrograms within the first 0.5 hours and then virtually does not change. The pellets retain spherical shape. Weight reduction during the drying is accompanied by the diameter reduction from 3.1 mm to 0.7-0.9 mm.
Example 6 Drying of Alginate Pellets Containing Magnetite using Sublimation Dehydration Method The magnetic pellets made as shown in Example 1 are frozen at -50 C
and then dried in the sublimation dehydration unit at the residual pressure of 1.1 Pa (Martin Chrict model ALFA 1-2 LD; Osterode am Harz, W, Germany) for 14 hours. Hereby the average weight of one pellet is reduced from 12.8 to 1.1 micrograms within the first 5 hours and then virtually does not change. The weight loss during the drying is accompanied by the pellets' shape change, they become disc-shaped (diameter 2.4 mm and thickness 0.25 mm).
Example 7 Drying of Alginate Pellets Containing Magnetite at Room Temperature in Vacuum The magnetic pellets made as shown in Example 1 are dried at the room temperature in vacuum (1-10-3 mm Hg) for 22 hours. Hereby the average weight of one pellet is reduced from 12.8 to 1.1 micrograms within the first 5 hours and then virtually does not change. The pellets retain spherical shape.
The weight loss during the drying is accompanied by the pellets' diameter reduction from 3.1 mm to 0.9-1.0 mm.
Claims (13)
1. Polymer pellet represented by the gel matrix from anionic polymer cross-linked with cations of multivalent metals characterized in that in the matrix ferromagnetic particles are dispersed with the ratio of weight concentrations of the ferromagnetic particles and anionic polymer from 0.5 to 5%.
2. Polymer pellet as per Claim 1 characterized in that anionic polysaccharide with the concentration of 0.1 - 2% is used as the anionic polymer.
3. Polymer pellet as per Claim 2 characterized in that sodium alginate or pectin with etherification degree of max. 30% is used as the anionic polysaccharide.
4. Polymer pellet as per Claim 2 characterized in that carboxymethyl cellulose or oxyethylcarboxymethyl cellulose is used as the anionic polysaccharide.
5. Polymer pellet as per Claim 1 characterized in that spherical or bar-shaped iron or iron oxides particles with the minimum size from 40 to 300 nm are used as ferromagnetic micro-particles.
6. Polymer pellet as per Claim 5 characterized in that magnetite or magenite particles are used as ferromagnetic micro-particles.
7. Method of locking gel plug formation including the delivery of gellating compound based on polymer capable of ionotropic gellation to the gel plug formation zone characterized in that the gellating compound is made as polymer pellets, each pellet being a gel matrix of anion polymer cross-linked with the cations of multivalent metals in which ferromagnetic particles are dispersed with the ferromagnetic particles' concentration from 0.5 to 5%. The locking gel plug is formed due to the pellets' intensive swelling provided by the ambient pH
increase to pH > 7 in the confined volume where they are retained by the external magnetic field.
increase to pH > 7 in the confined volume where they are retained by the external magnetic field.
8. Method of locking gel plug formation as per Claim 7 characterized in that external magnetic field with the intensity of 5,000-20,000 Oersted is used.
9 9. Method of locking gel plug as per Claim 7 formation characterized in that the polymer pellets are pre-dried.
10. Method of locking gel plug as per Claim 7 formation characterized in that the humidity of the dried polymer pellets is 15-25%.
11. Method of locking gel plug formation as per Claim 7 characterized in that to the pellet-swelling medium a substance stimulating polymer pellets' swelling is added.
12. Method of locking gel plug formation as per Claim 11 characterized in that the gel pellets swelling takes place in the alkaline medium containing soluble phosphates, polyphosphates, citrates or chelating agents like ethylenediaminotetraacetic acid (EDTA) sodium salt.
13. Method of locking gel plug formation as per Claim 7 characterized in that, the pellets are delivered by applying external magnetic field ensuring their migration to the gel plug formation zone.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/RU2007/000755 WO2009088319A1 (en) | 2007-12-29 | 2007-12-29 | Magnetic polymer granules and a method for forming a locking gel plug |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2710986A1 true CA2710986A1 (en) | 2009-07-16 |
Family
ID=40853279
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2710986A Abandoned CA2710986A1 (en) | 2007-12-29 | 2007-12-29 | Magnetic polymer pellets and a method of generating the blocking gel plug |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2710986A1 (en) |
| WO (1) | WO2009088319A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2796100A1 (en) * | 2013-04-23 | 2014-10-29 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Gelling system for the removal of kidney stone fragments |
| US9925311B2 (en) | 2013-04-23 | 2018-03-27 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Kit for producing a crosslinked gel for surrounding urinary calculi and/or fragments thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112096335B (en) * | 2020-09-05 | 2022-06-21 | 西南石油大学 | Shaft isolation method based on ionic liquid rubber plug |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4652257A (en) * | 1985-03-21 | 1987-03-24 | The United States Of America As Represented By The Secretary Of The Navy | Magnetically-localizable, polymerized lipid vesicles and method of disrupting same |
| DE4413350A1 (en) * | 1994-04-18 | 1995-10-19 | Basf Ag | Retard matrix pellets and process for their production |
| AUPM807094A0 (en) * | 1994-09-09 | 1994-10-06 | Commonwealth Scientific And Industrial Research Organisation | Polymer beads and method for preparation thereof |
| RU2113841C1 (en) * | 1996-04-16 | 1998-06-27 | Акционерное общество открытого типа Завод "Компонент" | Capsule for per os administering drugs with controlled drug supply |
| RU2167281C2 (en) * | 1999-08-04 | 2001-05-20 | Швецов Игорь Александрович | Method of nonuniform formation development |
| RU2298088C1 (en) * | 2005-09-30 | 2007-04-27 | Открытое акционерное общество "Татнефть" им. В.Д. Шашина | Method for non-uniform oil reservoir development |
-
2007
- 2007-12-29 WO PCT/RU2007/000755 patent/WO2009088319A1/en active Application Filing
- 2007-12-29 CA CA2710986A patent/CA2710986A1/en not_active Abandoned
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2796100A1 (en) * | 2013-04-23 | 2014-10-29 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Gelling system for the removal of kidney stone fragments |
| WO2014173467A1 (en) * | 2013-04-23 | 2014-10-30 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Gel-forming system for removing urinary calculi and fragments thereof |
| CN105491966A (en) * | 2013-04-23 | 2016-04-13 | 弗朗霍弗应用研究促进协会 | Gel-forming system for removing urinary calculi and fragments thereof |
| JP2016519957A (en) * | 2013-04-23 | 2016-07-11 | フラウンホーファー−ゲゼルシャフト・ツール・フェルデルング・デル・アンゲヴァンテン・フォルシュング・アインゲトラーゲネル・フェライン | Gel moldable system for removing urinary stones and fragments thereof |
| US9925311B2 (en) | 2013-04-23 | 2018-03-27 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Kit for producing a crosslinked gel for surrounding urinary calculi and/or fragments thereof |
| CN105491966B (en) * | 2013-04-23 | 2018-06-26 | 弗朗霍弗应用研究促进协会 | For removing the system of the formation gel of urethral calculus and/or urethral calculus fragment |
| AU2013387206B2 (en) * | 2013-04-23 | 2019-01-24 | Purenum Gmbh | Gel-forming system for removing urinary calculi and fragments thereof |
| US10232079B2 (en) | 2013-04-23 | 2019-03-19 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Gel-forming system for removing urinary calculi and fragments thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2009088319A1 (en) | 2009-07-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |
Effective date: 20130826 |