Novel nanoparticle-containing drilling fluids to mitigate fluid loss

Abstract

The present invention is directed to a well fluid, and in particular a drilling fluid having low amounts of nanoparticles which act as fluid loss material for reducing fluid loss in an underground formation. The fluid is a nanoparticle-containing well fluid comprising a base fluid and about 5 wt % or less nanoparticles, for preventing or reducing fluid loss to an underground formation, wherein the well fluid is a drilling fluid, kill fluid, completion fluid, or pre-stimulation fluid. The invention also includes in situ and ex situ methods of forming the nanoparticles.

1 . A nanoparticle-containing well fluid comprising a base fluid and about 5 wt % or less nanoparticles, for preventing or reducing fluid loss to an underground formation, wherein the well fluid is a drilling fluid, kill fluid, completion fluid, or pre-stimulation fluid. 
     
     
         2 . The well fluid of  claim 1  wherein the well fluid is a drilling fluid. 
     
     
         3 . The well fluid of  claim 2  wherein the drilling fluid is an invert emulsion drilling fluid. 
     
     
         4 . The fluid of  claim 1  wherein the nanoparticles are present in an amount of less than about 4 wt %, less than about 3 wt %, or less than about 1%. 
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . The fluid of  claim 1  wherein the nanoparticles are present in an amount of between about 0.1 to about 1 wt %; between about 0.5 to about 1.0 wt %; between about 0.6 to 1 wt %; or between about 0.74 to about 1 wt %. 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . The fluid of  claim 1  wherein the nanoparticles have a particle size of between about 1 to about 120 nm or between about 1 to about 30 nm. 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . The fluid of  claim 11  wherein substantially all of the nanoparticles have a particle size in the range of 1-30 nm. 
     
     
         15 . The fluid of  claim 1  wherein the nanoparticles are one or more of metal hydroxide, metal oxide, metal carbonate, metal sulfide, and metal sulfate. 
     
     
         16 . The fluid of  claim 15  wherein the nanoparticles are selected from the group consisting of iron hydroxide, iron oxide, calcium carbonate, iron sulfide, barium sulfate, or a mixture thereof. 
     
     
         17 . The fluid of  claim 15  wherein the nanoparticles are iron oxide formed from iron hydroxide in high pressure high temperature conditions in the underground formation. 
     
     
         18 . The fluid of  claim 1  wherein the nanoparticles are formed in situ in the fluid or formed ex situ and added to the fluid. 
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . The fluid of  claim 1  wherein the reduction of fluid loss is at least about 70% compared to a well fluid that does not contain loss circulation materials or nanoparticles. 
     
     
         25 . (canceled) 
     
     
         26 . (canceled) 
     
     
         27 . A method of making the nanoparticle-containing well fluid defined in  claim 1  by forming the nanoparticles ex situ, comprising the steps of providing aqueous-based precursor solutions for forming the nanoparticles, mixing the precursor solutions under high shear, and adding the mixed precursor solution to the well fluid, to form the nanoparticle-containing fluid, wherein the nanoparticles act as fluid loss material for reducing fluid loss in an underground formation. 
     
     
         28 . A method for making a nanoparticle-containing well fluid defined in  claim 1  by forming the nanoparticles in situ, comprising the steps of providing aqueous-based precursor solutions for forming the nanoparticles, adding the precursor solutions to the well fluid, and subjecting the fluid to mixing and shear to form the nanoparticle-containing fluid, wherein the nanoparticles act as a fluid loss material for reducing fluid loss in an underground formation. 
     
     
         29 . The method of  claim 28  wherein the fluid is an invert emulsion drilling fluid and the nanoparticles form in the dispersed water pools of the invert emulsion drilling fluid. 
     
     
         30 . The method of  claim 28  wherein the nanoparticle is iron (III) hydroxide. 
     
     
         31 . The method of  claim 29  wherein the aqueous-based precursor solutions comprise an aqueous based solution containing FeCl 3(aq)  and an aqueous based solution containing NaOH (aq) ; the aqueous-based solutions comprise an aqueous based solution containing Ca(NO) 3  and an aqueous based solution containing Na 2 CO 3 ; the aqueous-based solutions comprise an aqueous based solution containing BaCl 2  and an aqueous based solution containing Na 2 SO 4 ; or the aqueous-based solutions comprise an aqueous based solution containing Na 2 S and an aqueous based solution containing FeCl 2 . 
     
     
         32 . (canceled) 
     
     
         33 . (canceled) 
     
     
         34 . (canceled) 
     
     
         35 . The method of  claim 27  wherein the fluid is an invert emulsion drilling fluid and the nanoparticles form in the dispersed water pools of the invert emulsion drilling fluid. 
     
     
         36 . The method of  claim 27  wherein the nanoparticle is iron (III) hydroxide. 
     
     
         37 . The method of  claim 27  wherein the aqueous-based precursor solutions comprise an aqueous based solution containing FeCl 3(aq)  and an aqueous based solution containing NaOH (aq) ; the aqueous-based solutions comprise an aqueous based solution containing Ca(NO) 3  and an aqueous based solution containing Na 2 CO 3 ; the aqueous-based solutions comprise an aqueous based solution containing BaCl 2  and an aqueous based solution containing Na 2 SO 4 ; or the aqueous-based solutions comprise an aqueous based solution containing Na 2 S and an aqueous based solution containing FeCl 2 .