Patent EA-005154-B1 (EA)
Title: Well treatment
Inventor: KOTLAR HANS
IPC: C09K8/536
Filed: 2001-11-19
Abstract: 1. A method for the treatment of a hydrocarbon well which method comprises administering down said well polymeric particles impregnated with a well treatment chemical or precursor or generator thereof, said particles having a pore volume of at least 20%, and being prepared by a process which comprises preparing in a first step an aqueous dispersion of polymer particles containing from 0.05 to 10 times by volume, based on the polymer, of one or more materials having a watersolubility of < 10<-2> g/l and having a molecular weight of < 5000g/mol (herein referred to as Substance I) said Substance I not being an oligomer of the polymer forming the particles and being non-crystalline at the temperature at which it is incorporated into the particles and is in liquid form at the temperature at which Substance II is introduced in a second step, and in said second step adding a partly water-soluble material (herein referred to as Substance II) having a water-solubility of at least ten times that of Substance I under conditions which prevent or hinder transport of Substance I through the aqueous phase, whereby Substance II diffuses into the polymer particles swelled with Substance I and increases the volume of said particles by from 20 to 1000 times, based on the polymer. 2. A method as claimed in claim 1 wherein said polymeric particles are administered down said well before hydrocarbon production from said well begins. 3. A method as claimed in either of claims 1 and 2 wherein said polymeric particles are placed in a filter in the bore-hole of said well and within the formation surrounding said bore-hole. 4. A method as claimed in any one of claims 1 to 3 wherein as said polymeric particles are used particles as claimed in either one of claims 6 and 7. 5. Polymeric particles impregnated with a well treatment chemical or precursor or generator thereof, said particles having a pore volume of at least 20%, and being prepared by a process which comprises preparing in a first step an aqueous dispersion of polymer particles containing from 0.05 to 10 times by volume, based on the polymer, of one or more materials having a watersolubility of < 10<-2> g/l and having a molecular weight of < 5000 g/mol (herein referred to as Substance I) said Substance I not being an oligomer of the polymer forming the particles and being non-crystalline at the temperature at which it is incorporated into the particles and is in liquid form at the temperature at which Substance II is introduced in a second step, and in said second step adding a partly water-soluble material (herein referred to as Substance II) having a water-solubility of at least ten times that of Substance I under conditions which prevent or hinder transport of Substance I through the aqueous phase, whereby Substance II diffuses into the polymer particles swelled with Substance I and increases the volume of said particles by from 20 to 1000 times, based on the polymer. 6. Polymeric particles as claimed in claim 5 wherein said well treatment chemical or precursor or generator thereof is selected from scale inhibitors, corrosion inhibitors, wax inhibitors, asphaltene inhibitors, foamers, biocides, surfactants, oxygen scavengers and bacteria. 7. Polymeric particles as claimed in claim 6 impregnated with a scale inhibitor selected from inulins, phytic acid, phytic acid derivatives and polyaspartates. 8. A hydrocarbon well treatment composition comprising a carrier liquid containing polymeric particles impregnated with a well treatment chemical or precursor or generator thereof, said particles having a pore volume of at least 20%, and being prepared by a process which comprises preparing in a first step an aqueous dispersion of polymer particles containing from 0.05 to 10 times by volume, based on the polymer, of one or more materials having a watersolubility of < 10<-2> g/l and having a molecular weight of < 5000 g/mol (herein referred to as Substance I) said Substance I not being an oligomer of the polymer forming the particles and being non-crystalline at the temperature at which it is incorporated into the particles and is in liquid form at the temperature at which Substance II is introduced in a second step, and in said second step adding a partly water-soluble material (herein referred to as Substance II) having a water-solubility of at least ten times that of Substance I under conditions which prevent or hinder transport of Substance I through the aqueous phase, whereby Substance II diffuses into the polymer particles swelled with Substance I and increases the volume of said particles by from 20 to 1000 times, based on the polymer. 9. A composition as claimed in claim 8 comprising polymeric particles as claimed in one of claims 6 and 7. 10. A tubular filter for down-hole placement containing polymeric particles impregnated with a well treatment chemical or precursor or generator thereof, said particles having a pore volume of at least 20%, and being prepared by a process which comprises preparing in a first step an aqueous dispersion of polymer particles containing from 0.05 to 10 times by volume, based on the polymer, of one or more materials having a watersolubility of < 10<-2> g/l and having a molecular weight of < 5000g/mol (herein referred to as Substance I) said Substance I not being an oligomer of the polymer forming the particles and being non-crystalline at the temperature at which it is incorporated into the particles and is in liquid form at the temperature at which Substance II is introduced in a second step, and in said second step adding a partly water-soluble material (herein referred to as Substance II) having a water-solubility of at least ten times that of Substance I under conditions which prevent or hinder transport of Substance I through the aqueous phase, whereby Substance II diffuses into the polymer particles swelled with Substance I and increases the volume of said particles by from 20 to 1000 times, based on the polymer. 11. A filter as claimed in claim 10 comprising a particulate filter matrix of which said polymeric particles constitute 2 to 30% wt. 12. A filter as claimed in either of claims 10 and 11 comprising polymeric particles as claimed in one of claims 6 and 7. 13. The use for the manufacture of hydrocarbon well treatment compositions of polymeric particles impregnated with a well treatment chemical or precursor or generator thereof, said particles having a pore volume of at least20%, and being prepared by a process which comprises preparing in a first step an aqueous dispersion of polymer particles containing from 0.05 to 10 times by volume, based on the polymer, of one or more materials having a water-solubility of < 10<-2> g/l and having a molecular weight of < 5000 g/mol (herein referred to as Substance I) said Substance I not being an oligomer of the polymer forming the particles and being non-crystalline at the temperature at which it is incorporated into the particles and is in liquid form at the temperature at which Substance II is introduced in a second step, and in said second step adding a partly water-soluble material (herein referred to as Substance II) having a water-solubility of at least ten times that of Substance I under conditions which prevent or hinder transport of Substance I through the aqueous phase, whereby Substance II diffuses into the polymer particles swelled with Substance I and increases the volume of said particles by from 20 to 1000 times, based on the polymer. 14. The use as a down-hole scale inhibitor of a material selected from inulins, phytic acid, phytic acid derivatives and polyaspartates.