Determination of oil saturation in reservoir rock using paramagnetic nanoparticles and magnetic field

Abstract

Methods for detection of the presence and distribution of oil in subsurface formation are described herein. The present invention involves injection of an aqueous dispersion of the nanoparticles into the potentially oil containing subsurface formation, followed by a remote detection of the oscillation responses of the nanoparticles in the oil/water interfaces in the reservoir rock by applying magnetic field.

What is claimed is: 
     
         1 . A composition comprising:
 one or more coated paramagnetic nanoparticles, wherein the paramagnetic nanoparticles are coated with a polymer, a surfactant or any combinations thereof adapted for a downhole administration; and   a fluid comprising the one or more coated paramagnetic nanoparticles, wherein the fluid is selected from the group consisting of water, hard water, brine, and any combinations thereof, wherein the composition is operable for detecting a presence, measuring a distribution or both of an oil or a hydrocarbon in a subsurface formation.   
     
     
         2 . The composition of  claim 1 , wherein the coated paramagnetic nanoparticles comprise a metal oxide. 
     
     
         3 . The composition of  claim 2 , wherein a metal in the metal oxide comprises at least one of iron, magnesium, molybdenum, lithium, cobalt, nickel or tantalum. 
     
     
         4 . (canceled) 
     
     
         5 . The composition of  claim 1 , wherein the nanoparticles are coated by adsorption of a thin polymer gel film or a coating material around the paramagnetic nanoparticles, wherein the thin polymer gel film is wrapped around the paramagnetic nanoparticles to prevent a detachment of the coating during a transport of the nanoparticle in the subsurface formation. 
     
     
         6 . The composition of  claim 5 , wherein the coating is configured to promote a high salinity tolerance to the nanoparticles for monovalent and divalent salts. 
     
     
         7 . The composition of  claim 5 , wherein the detachment of the coating is prevented by a chemical bond of the polymer gel film or the coating material to itself or to another agent on the nanoparticle surface. 
     
     
         8 . The composition of  claim 7 , wherein the chemical bond of the polymer gel film or the coating material is achieved by contacting the paramagnetic nanoparticles suspended in an aqueous solution with the polymer, a cross-linker, a catalyst, a first stabilizer, and a second stabilizer. 
     
     
         9 . (canceled) 
     
     
         10 . The composition of  claim 8 , wherein the polymers are selected from the group consisting of polyacrylic acid (PAA), block copolymer of poly(acrylic acid) m -b-poly(butyl acrylate) n , random copolymer of poly(acrylic acid) m -r-poly(butyl acrylate) n , poly(4-styrene sulfonic acid-co-maleic acid), polyethylene glycol, styrene sulfonic acids, acrylic and methacrylic acid polymers and copolymers, polylactic acid copolymers (PLA) and polylactic glycolic acid (PLGA), vinyl sulfonic acid, vinyl benzyl trimethyl ammonium chloride, acrylamidopropyl trimethyl ammonium chloride, polyethylene oxide, polypropylene oxide, and combinations or modifications thereof, wherein m and n are the number of monomers. 
     
     
         11 . The composition of  claim 8 , wherein the cross-linker comprises 1,6-hexanediamine. 
     
     
         12 . The composition of  claim 8 , wherein the catalyst is selected from the group consisting of carbodiimides, N-hydroxysuccinimide esters, imidoesters, maleimides, haloacetyls, pyridyl disulfides, and aryl azides. 
     
     
         13 . The composition of  claim 8 , wherein the catalyst is 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. 
     
     
         14 . (canceled) 
     
     
         15 . The composition of  claim 8 , wherein the second stabilizer increases an adsorption of the one or more paramagnetic nanoparticles at an oil-water interface to provide an enhanced imaging of the oil and decreases an adsorption at the subsurface formation or a rock surface to promote the transfer of the one or more nanoparticles in the subsurface formation or a reservoir. 
     
     
         16 . (canceled) 
     
     
         17 . The composition of  claim 8 , wherein the polymer is a poly(acrylic acid) m -b-poly(butyl acrylate) n  block copolymer or a poly(acrylic acid) m -r-poly(butyl acrylate) n  random copolymer, where m and n are the numbers of (acrylic acid) and (butyl acrylate) monomers, respectively, wherein m and n can be adjusted for improved salt tolerance and interfacial activity. 
     
     
         18 . The composition of  claim 8 , wherein the polymer is a poly(4-styrenesulfonic acid-co-maleic acid) copolymer. 
     
     
         19 .- 52 . (canceled) 
     
     
         53 . A composition comprising:
 (a) a plurality of coated paramagnetic nanoparticles, wherein
 (i) each of the coated paramagnetic nanoparticles has a coating that is a polymer, a surfactant, or a combination thereof, and 
 (ii) the coating is suitable for a subterranean reservoir; and 
   (b) a fluid in which the plurality of coated paramagnetic nanoparticles are intermixed, wherein
 (i) the fluid is selected from the group consisting of water, hard water, brine, and combinations thereof, and 
 (ii) the composition is suitable for detecting a presence of a hydrocarbon in subterranean reservoir, measuring a distribution of the hydrocarbon in the subterranean reservoir, or both. 
   
     
     
         54 . The composition of  claim 53 , wherein the coated paramagnetic nanoparticles comprise a metal oxide, wherein the metal oxide is selected from the group consisting of oxides of iron, magnesium, molybdenum, lithium, cobalt, nickel, tantalum, and combinations thereof. 
     
     
         55 .- 57 . (canceled) 
     
     
         58 . The composition of  claim 53 , wherein
 (a) the coated paramagnetic nanoparticles are coated by adsorption of a thin polymer gel film around the paramagnetic nanoparticles, and   (b) the thin polymer gel film is wrapped around the paramagnetic nanoparticles to operably prevent a detachment of the coating during a transport of the paramagnetic nanoparticle in the subterranean reservoir, wherein the coating is configured to promote a high salinity tolerance to the paramagnetic nanoparticles for monovalent and divalent salts.   
     
     
         59 .- 61 . (canceled) 
     
     
         62 . The composition of claim  60 , wherein the polymers are selected from the group consisting of polyacrylic acid (PAA), block copolymer of poly(acrylic acid) m -b-poly(butyl acrylate) n , random copolymer of poly(acrylic acid) m -r-poly(butyl acrylate) n , poly(4-styrene sulfonic acid-co-maleic acid), polyethylene glycol, styrene sulfonic acids, sulfonic acids, polystyrene, acrylic and methacrylic acid polymers and copolymers, polylactic acid copolymers (PLA) and polylactic glycolic acid (PLGA), styrene sulfonic acid, vinyl sulfonic acid, vinyl benzyl trimethyl ammonium chloride, acrylamidopropyl trimethyl ammonium chloride, polyethylene oxide, polypropylene oxide, and combinations or modifications thereof, wherein m and n are the number of monomers. 
     
     
         63 .- 67 . (canceled) 
     
     
         68 . The composition of  claim 53 , wherein
 (a) the coating is a polymer;   (b) the polymer is selected from the group consisting of a Poly(acrylic acid) m -b-Poly(butyl acrylate) n  block copolymer, and a Poly(acrylic acid) m -r-Poly(butyl acrylate) n  random copolymer, where m and n are the numbers of (acrylic acid) and (butyl acrylate) monomers, respectively.   
     
     
         69 . The composition of  claim 53 , wherein the coating is a polymer, and the polymer is a Poly(4-styrenesulfonic acid-co-maleic acid) polymer. 
     
     
         70 .- 83 . (canceled)