Re-assembling polymer particle package for conformance control and fluid loss control
View Patent ↗This invention is broadly concerned with compositions and processes for oilfield applications. More specifically, this invention relates to novel polymer constructed packages that, when pumped into a petroleum well, provide tunable characteristics of transformation and delayed self-assembly with each other under reservoir conditions to yield strong, elastic, bulk gel materials. The compositions comprise a polymer, assembling agents, and optional additives used for the re-assembly stage are uniformly-distributed within the initial gel particles. The polymer particle packages absorb water and swell upon exposure to water, thus exposing the “assembling agents” that enable re-assembly. Both swelling and re-assembly are proportionally controlled via compositions to be tunable to allow functional dispersion and subsequent self-assembly under various reservoir conditions.
1. A composition useful for controlling fluid flow, said composition comprising a plurality of swellable particles, said particles comprising an assembling agent interspersed among crosslinkable polymer chains, said assembling agent being:
one that will associate with the polymer chains upon exposure to a fluid capable of swelling the polymer chains; and
selected from the group consisting of polyacrylamide, one of the multivalent Group III-VII transition metal molecules, methylene bisacrylamide, polyethylene glycol, dimethacrylate, phenol-formaldehyde, diallylamine, triallylamine, divinyl sulfonate, diethylene glycol, polyethyleneimine, dichlorophenol, benzoyl peroxide, di-tert-butyl peroxide, dibutyl hydrogen phosphite, and mixtures thereof.
2. The composition of claim 1 , wherein said assembling agent is selected from the group consisting of Cr, Zr, Co, Ti, and Al molecules or ions; anionic species such as those selected from the group consisting of acetates, alkyl carboxylates, chlorides, nitrates, fluorides, carbonates, hydroxyls; and combinations of the foregoing.
3. The composition of claim 1 , wherein said crosslinkable polymer chain is selected from the group consisting of polymers or copolymers of hydrolyzed polyacrylamide, polyacrylamide, chloroprene rubber, nitrile rubber, hydrophilic resin sulfonate, acrylamide, lauryl methacrylate, stearyl methacrylate, silicates, N, N-dimethylacrylamide, and combinations of the foregoing.
4. The composition of claim 1 , wherein the weight ratio of crosslinkable polymer chains to assembling agent is from about 2:1 to about 200:1.
5. The composition of claim 1 , said particles further comprising an additive selected from the group consisting of tackifiers, plasticizers, crosslinking agents, polymers other than said crosslinkable polymer, aromatic compounds, polysaccharides, deoxidants, adjustors of gelant, nanoclays, initiators, stabilizers, accelerators, and mixtures thereof.
6. The composition of claim 1 , wherein the average particle size of said swellable particles is from about 80 nm to about 10 mm.
7. The composition of claim 1 , wherein said particles have an initial average particle size, and said particles are swellable to a size that is at least about 30 times that of the initial average particle size.
8. The composition of claim 1 , wherein said particles have an initial average particle size, and said particles are swellable to a size that is from about 10 times to about 200 times, and preferably from about 30 times to about 100 times, that of the initial average particle size.
9. A method of forming a composition useful for controlling fluid flow, said method comprising:
(a) polymerizing a plurality of monomers in the presence of a source of an assembling agent so as to form crosslinkable polymer chains;
(b) drying and reducing the average particle size of the product resulting from (a) to yield a plurality of swellable particles comprising said assembling agent interspersed among said crosslinkable polymer chains, said assembling agent being:
(i) one that will associate with the polymer chains upon exposure to a fluid; and
(ii) selected from the group consisting of monomers, oligomers, polymers, copolymers, Group III-VII transition metal containing molecules, Group III-VII transition metal ions, methylene bisacrylamide, polyethylene glycol, dimethacrylate, phenol-formaldehyde, diallylamine, triallylamine, divinyl sulfonate, diethylene glycol, aldehydes, polyethyleneimine, dichlorophenol, benzoyl peroxide, di-tert-butyl peroxide, dibutyl hydrogen phosphite, and mixtures thereof.
10. The method of claim 9 , wherein said assembling agent is selected from the group consisting of Cr, Zr, Co and Al molecules or ions, organic compounds such as those selected from the group consisting of polyethylene glycol, dimethacrylate, phenol-formaldehyde, diallylamine, triallylamine, divinyl sulfonate, diethylene glycol diallyl aldehydes, polyethyleneimine, and combinations of the foregoing.
11. The method of claim 9 , wherein said crosslinkable polymer chain formed in (a) is selected from the group consisting of polymers or copolymers of hydrolyzed polyacrylamide, polyacrylamide, xanthan, guar, chloroprene rubber, nitrile rubber, hydrophilic resin sulfonate, acrylamide, lauryl methacrylate, stearyl methacrylate, silicates, and combinations of the foregoing.
12. The method of claim 9 , wherein the weight ratio of crosslinkable polymer chains to assembling agent in the particles resulting from (b) is from about 2:1 to about 200:1.
13. The method of claim 9 , said particles resulting from (b) further comprising an additive selected from the group consisting of tackifiers, plasticizers, crosslinking agents, polymers other than said crosslinkable polymer, aromatic compounds, polysaccharides, deoxidants, adjustors of gelant, nanoclay, initiators, accelerators, stabilizers, and mixtures thereof.
14. The method of claim 9 , wherein said source of assembling agent is selected from the group consisting of zirconium-acetate, chromium-acetate, aluminum acetate, aluminum citrate, cobalt acetate, zirconyl chloride, and mixtures of the foregoing.
15. The method of claim 9 , wherein the average particle size of said particles resulting from (b) is from about 80 nm to about 10 mm.
16. The method of claim 9 , wherein said particles resulting from (b) have an initial average particle size, and said particles are swellable to an average particle size that is at least about 40 times that of the initial average particle size.
17. The method of claim 9 , wherein said particles resulting from (b) have an initial average particle size, and said particles are swellable to a size that is from about 20 times to about 200 times that of the initial average particle size.