Masterbatch for manufacturing a drilling fluid

Abstract

An oil-based masterbatch in the form of granules containing carbon nanotubes. Also, a method for preparing an oil-based masterbatch in the form of granules containing carbon nanotubes. Also, the use of an oil-based masterbatch in the form of granules containing carbon nanotubes for manufacturing an aqueous or organic viscoelastic fluid, intended for drilling in underground formations.

1 - 13 . (canceled) 
     
     
         14 . Process for the manufacture of a viscoelastic fluid for drilling subterranean rock formations, which comprises mixing a masterbatch with an aqueous and/or organic liquid base and optionally at least one weighting agent in particulate form to form the viscoelastic fluid for drilling subterranean rock formations,
 wherein the masterbatch comprises at least one oil and more than 3% by weight of carbon nanotubes having a mean diameter of between 5 and 30 nm and a specific surface area greater than 200 m 2 /g,   said oil being chosen from: vegetable oils having a high content of triglycerides, consisting of esters of fatty acids and of glycerol; synthetic oils of formula R 5 COOR 6  in which R 5  represents an aryl group or the residue of a higher, linear or branched, fatty acid having 7 to 30 carbon atoms and R 6  represents a branched or unbranched hydrocarbon chain, possibly hydroxylated, containing 3 to 30 carbon atoms; synthetic ethers; linear or branched, saturated or unsaturated, C 6  to C 26  fatty alcohols; mineral oils; cyclic hydrocarbons; aromatic hydrocarbons; fluorinated oils; fluorosilicone oils; and mixtures thereof;   wherein the masterbatch is in the form of solid granules.   
     
     
         15 . The process of  claim 14 , wherein the carbon nanotubes are multi-walled carbon nanotubes having from 3 to 15 sheets. 
     
     
         16 . The process of  claim 15 , wherein the multi-walled carbon nanotubes have from 5 to 10 sheets. 
     
     
         17 . The process of  claim 15 , wherein the masterbatch contains from 10 to less than 60% by weight of the multi-walled carbon nanotubes. 
     
     
         18 . The process of  claim 14 , wherein the process comprises mixing with the at least one weighting agent, wherein said weighting agent has a density of at least 2 g/cm 3 . 
     
     
         19 . The process of  claim 14 , wherein the process comprises mixing with the at least one weighting agent, wherein the weighting agent is barite. 
     
     
         20 . The process of  claim 14 , the process further comprising subjecting the masterbatch and the liquid base to a mechanical treatment using ultrasound or a rotor-stator system or a blade mixer. 
     
     
         21 . The process of  claim 14 , in which the masterbatch is incorporated directly into the final formulation of the viscoelastic drilling fluid. 
     
     
         22 . The process of  claim 14 , wherein the viscoelastic fluid contains 0.1 to 6% by weight of carbon nanotubes. 
     
     
         23 . The process of  claim 14 , wherein the masterbatch contains 10 to 55% by weight of the carbon nanotubes. 
     
     
         24 . Process for the manufacture of a viscoelastic fluid for drilling subterranean rock formations, which comprises mixing a masterbatch with an aqueous and/or organic liquid base and optionally at least one weighting agent in particulate form to form the viscoelastic fluid for drilling subterranean rock formations,
 wherein the masterbatch consists of at least one oil and of more than 3% by weight of carbon nanotubes having a mean diameter of between 5 and 30 nm and a specific surface area greater than 200 m 2 /g.   
     
     
         25 . The process of  claim 24 , wherein the carbon nanotubes are multi-walled carbon nanotubes having from 3 to 15 sheets. 
     
     
         26 . The process of  claim 25 , wherein the masterbatch contains from 10 to less than 60% by weight of the multi-walled carbon nanotubes. 
     
     
         27 . The process of  claim 25 , wherein the multi-walled carbon nanotubes have from 5 to 10 sheets. 
     
     
         28 . The process of  claim 24 , wherein the at least one oil is chosen from oils having a dynamic viscosity at room temperature of between 0.1 cP and 500 cP. 
     
     
         29 . The process of  claim 24 , wherein the process comprises mixing with the at least one weighting agent, wherein said weighting agent has a density of at least 2 g/cm 3 . 
     
     
         30 . The process of  claim 24 , wherein the process comprises mixing with the at least one weighting agent, wherein the weighting agent is barite. 
     
     
         31 . The process of  claim 24 , wherein the viscoelastic fluid contains 0.1 to 6% by weight of carbon nanotubes. 
     
     
         32 . The process of  claim 24 , wherein the masterbatch contains 10 to 55% by weight of the carbon nanotubes. 
     
     
         33 . The process of  claim 24 , the process further comprising subjecting the masterbatch and the liquid base to a mechanical treatment using ultrasound or a rotor-stator system or a blade mixer. 
     
     
         34 . The process of  claim 24 , in which the masterbatch is incorporated directly into the final formulation of the viscoelastic drilling fluid. 
     
     
         35 . The process of  claim 24 , wherein the masterbatch is in the form of solid granules. 
     
     
         36 . A process comprising drilling subterranean rock formations with a viscoelastic fluid, wherein the viscoelastic fluid is formed by mixing a masterbatch with an aqueous and/or organic liquid base and optionally at least one weighting agent in particulate form to form the viscoelastic fluid for drilling subterranean rock formations,
 wherein the masterbatch comprises at least one oil and more than 3% by weight of carbon nanotubes having a mean diameter of between 5 and 30 nm and a specific surface area greater than 200 m 2 /g,   said oil being chosen from: vegetable oils having a high content of triglycerides, consisting of esters of fatty acids and of glycerol; synthetic oils of formula R 5 COOR 6  in which R 5  represents an aryl group or the residue of a higher, linear or branched, fatty acid having 7 to 30 carbon atoms and R 6  represents a branched or unbranched hydrocarbon chain, possibly hydroxylated, containing 3 to 30 carbon atoms; synthetic ethers; linear or branched, saturated or unsaturated, C 6  to C 26  fatty alcohols; mineral oils; cyclic hydrocarbons; aromatic hydrocarbons; fluorinated oils; fluorosilicone oils; and mixtures thereof;   wherein the masterbatch is in the form of solid granules.   
     
     
         37 . A process comprising drilling subterranean rock formations with a viscoelastic fluid, wherein the viscoelastic fluid is formed by mixing a masterbatch with an aqueous and/or organic liquid base and optionally at least one weighting agent in particulate form to form the viscoelastic fluid for drilling subterranean rock formations,
 wherein the masterbatch consists of at least one oil and of more than 3% by weight of carbon nanotubes having a mean diameter of between 5 and 30 nm and a specific surface area greater than 200 m 2 /g.