Method for the fracture stimulation of a subterranean formation having a wellbore by using thermoset polymer nanocomposite particles as proppants, where said particles are prepared by using formulations containing reactive ingredients obtained or derived from renewable feedstocks

Abstract

A method for fracture stimulation of a subterranean formation having a wellbore includes providing a thermoset polymer nanocomposite particle precursor composition comprising a polymer precursor mixture, dispersed within a liquid medium, containing at least one of a monomer, an oligomer or combinations thereof having three or more reactive functionalities capable of creating crosslinks between polymer chains, wherein 1% to 100% by weight of said polymer precursor mixture is obtained or derived from a renewable feedstock; and from 0.001 to 60 volume percent of nanofiller particles possessing a length that is less than 0.5 microns in at least one principal axis direction; subjecting the nanocomposite particle precursor composition to polymerizing conditions to form the polymeric nanocomposite particle, whereby said nanofiller particles are substantially incorporated into a polymer; forming a slurry comprising a fluid and a proppant, wherein said proppant comprises the nanocomposite particles, said nanocomposite particles being formed from a rigid thermoset polymer matrix; and injecting into the wellbore said slurry at sufficiently high rates and pressures such that said formation fails and fractures to accept said slurry.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of U.S. patent application Ser. No. 11 / 323,031 entitled “Thermoset Nanocomposite Particles, Processing For Their Production, And Their Use In Oil And Natural Gas Drilling Applications”, filed Dec. 30, 2005, which claims priority to U.S. Provisional Application No. 60 / 640,965 filed Dec. 30, 2004. This application is also a continuation-in-part of U.S. patent application Ser. No. 11 / 451,697 entitled “Thermoset Particles With Enhanced Crosslinking, Processing For Their Production, And Their Use In Oil And Natural Gas Drilling Applications”, filed Jun. 13, 2006. This application is also a continuation-in-part of U.S. patent application Ser. No. 11 / 695,745 entitled “A Method For The Fracture Stimulation Of A Subterranean Formation Having A Wellbore By Using Impact-Modified Thermoset Polymer Nanocomposite Particles As Proppants,” filed Apr. 3, 2007. The contents of prior application Ser. Nos. 11 / 323,...

AI Technical Summary

Benefits of technology

[0078] Without reducing the generality of the invention, among renewable feedstocks that can be used for the synthesis of the matrix polymer of the nanocomposite particles, natural fats and oils extracted from some common types of plants [such as soybean, sunflower, canola, castor, olive, peanut, cashew nut, pumpkin seed, rapeseed, corn, rice, sesame, cottonseed, palm, coconut, safflower, linseed (also known as flaxseed), hemp, tall oil, and similar natural fats and oils; and especially soybean, sunflower, canola and linseed oils] appear to be very promising as potential sources of inexpensive monomers.

[0085] Without reducing the generality of the invention, it is especially practical to use methods that can produce the particles directly in the desired (usually substantially spherical) shape during polymerization from the starting monomers.

[0092] In some instances, there may also be further benefits of a post-polymerization process step. One such possible additional benefit is an enhancement in the flow of the gases, fluids, or mixtures thereof, produced by the subterranean formation, towards the wellbore, even at temperatures that are far below the maximum possible application temperature of the fracture stimulation method. Another such possible additional benefit is an increase of such magnitude in the resistance of the particles to aggressive environments as to enhance significantly the potential range of applications of the fracture stimulation method utilizing the particles.

[0096] Optionally, the thermoset nanocomposite particles used in implementing the fracture stimulation method of the invention may be coated; to achieve benefits such as protection from chemicals, waterproofing, hardening, and combinations thereof.

[0102] Without reducing the generality of the invention, the use of a fluidized bed process as a post-polymerization step is a preferred method for the placement of a coating if needed, but it is most preferred to select a matrix polymer composition such that a coating will not be needed.

Problems solved by technology

Consequently, while there are many potential applications for composites (prepared from renewable feedstocks) where biodegradability and / or other types of environmental degradability are among the key target properties, such composites are not optimal for use as proppants in implementing the fracture stimulation method of the invention, and will hence not be discussed further.

However, they were highly susceptible to water absorption in humid environments.

Water absorption caused their mechanical properties to deteriorate significantly.

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