Method for the treatment and prevention of asphaltene-paraffin-vax precipitates in oil-wells, wellheads and pipelines by the use of biocolloid suspensions

Abstract

The method for the prevention, reduction and/or removal of asphaltene-paraffin-vax precipitates on surfaces in contact with crude oil within oil-wells from bottom hole to well head, in flow lines and pipelines by the use of biocolloid suspensions comprises the steps of: adding together (a) microorganism(s) capable of reacting with, solubilizing of and/or resistant to the components of crude oil, (b) organic or inorganic additives, or (c) a mixture thereof into the pipes; and allowing the so formed suspension containing the microorganisms to act for a desired time. The suspension is used for the decomposition, washing-off and removal of solid hydrocarbons and mixtures of long chain hydrocarbons, as well as for the prevention of formation thereof.

1 - 18 . (canceled)  
   
   
       19 . Method for the removal of asphaltene-paraffin-vax precipitates and prevention of formation thereof on surfaces in contact with crude oil, comprising 
 a) adding tensides, material for increasing viscosity, and microorganisms capable of breaking down crude oil components or derivatives and producing at least one type of tenside, to the surface, optionally together with additives required for the reproduction of said microorganisms;    b) providing an appropriate temperature for the microorganisms after the addition of the materials in step a);    c) allowing the microorganisms to reproduce and act for a predetermined period of time on the surface;    d) checking the results of the treatment; and    e) optionally repeating steps (a) to (d) at least once more, preferably at least three more times,    thereby forming a film carrying bacteria on the surface in contact with the crude oil.    
   
   
       20 . The method according to  claim 19 , wherein said biodegradable macromolecular material for increasing viscosity is Supramil, xanthan, or other water soluble macromolecule, such as starch, cellulose derivative, and preferably xanthan.  
   
   
       21 . The method according to  claim 19 , wherein the said precipitates are removed from or prevented in the inner surfaces of tubing of oil-wells, flow lines thereof or in oil pipelines.  
   
   
       22 . The method according to  claim 19 , wherein the said microorganisms and additives are added to the surface at the same time, in the form of an aqueous suspension.  
   
   
       23 . The method according  claim 22 , wherein the suspension of microorganisms contain 10 6  to 10 12  CFU/liter, preferably 10 7  to 10 11  CFU/liter, more preferably 10 8  to 10 9  CFU/liter.  
   
   
       24 . The method according to  claim 22 , wherein the volume of the suspension is 100 to 1000 liter/100 m pipe-length, preferably 300 to 800 liter/100 m pipe-length, more preferably 500 to 600 liter/100 m pipe-length.  
   
   
       25 . The method according to  claim 24 , wherein the microorganisms are allowed to reproduce and act for 1 to 15 days, preferably for 6 to 8 days, while the pipes are kept closed.  
   
   
       26 . The method according to  claim 19 , performed in a production oil-well, and temperature in the well is determined by the geological conditions.  
   
   
       27 . The method according to  claim 21 , wherein the results of the treatment are checked by pilot test and by mechanical cleaning test and/or by evaluating the physico-chemical properties, preferably the decrease of viscosity of an oil sample and/or evaluating the drop-size of the asphaltene-paraffin-vax precipitates in an oil-sample by microscopy.  
   
   
       28 . The method according to  claim 19 , wherein the surfactant is selected from the group consisting of polyoxyethylene ethers and esters, and mixtures thereof, preferably Tween 80.  
   
   
       29 . The method according to claims  19 , wherein the asphaltene-paraffin-vax precipitates are removed from the surface in advance by mechanical means.  
   
   
       30 . Use of biodegradable macromolecular polymeric material for increasing viscosity and microorganism capable of braking down crude oil components or derivatives and producing at least one type of tenside for the removal and prevention of asphaltene-paraffin-vax precipitates by way of forming a film carrying bacteria on surfaces in contact with crude oil.  
   
   
       31 . The use according to  claim 30 , wherein the biodegradable macromolecular material for increasing viscosity is Supramil, xanthan, or other water soluble macromolecule, such as starch, cellulose derivative, and preferably xanthan.  
   
   
       32 . The use according to  claim 30 , wherein the microorganism is strain belonging to the  Bacillus subtilies  species, the  Bacillus cereus  species, the  Pseudomonas  genus or the  Xanthomonas  genus, and preferably facultative anaerobic.  
   
   
       33 . The use according to  claim 30 , wherein the microorganism is selected form the group consisting strains NCAIM (P) B 1304, NCAIM (P) B 1305, NCAIM (P) B 1306, NCAIM (P) B 1307 and NCAIM (P) B 1038 deposited on Apr. 17, 2002 at NCAIM, or any strain derived therefrom, and preferably is a strain that is genetically modified, more preferably modified by the insertion of a DNA fragment with a known sequence as a marker.  
   
   
       34 . Kit for the removal or prevention of asphaltene-paraffin-vax precipitates on surfaces in contact with crude oil in pipelines, comprising a microorganism useful in the method of claim  1 , biodegradable macromolecular polymeric material for increasing viscosity, and further comprising instructions to carry out the method of claim  18 .  
   
   
       35 . The kit according to  claim 34 , wherein the biodegradable macromolecular material for increasing viscosity is Supramil, xanthan, or other water soluble macromolecule, such as starch, cellulose derivative, and preferably xanthan.  
   
   
       36 . The kit according to  claim 34  comprising one or more of the microorganisms selected from the  Bacillus subtilies  species, the  Bacillus cereus  species, the  Pseudomonas  genus, the  Xanthomonas  genus, strains NCAIM (P) B 1304, NCAIM (P) B 1305, NCAIM (P) B 1306, NCAIM (P) B 1307 and NCAIM (P) B 1038 deposited on Apr. 17, 2002 at NCAIM, or any strain derived therefrom and additions necessary to the reproduction thereof.