News Column

"Nanoparticle Modified Fluids and Methods of Manufacture Thereof" in Patent Application Approval Process

May 1, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- A patent application by the inventors Chakraborty, Soma (Houston, TX); Johnson, Michael H. (Katy, TX), filed on October 10, 2012, was made available online on April 17, 2014, according to news reporting originating from Washington, D.C., by VerticalNews correspondents.

This patent application is assigned to Baker Hughes Incorporated.

The following quote was obtained by the news editors from the background information supplied by the inventors: "Disclosed herein are nanoparticle modified fluids and methods of manufacture thereof. In particular disclosed herein are nanoparticle modified fluids that are used for enhanced oil recovery from subterranean hydrocarbon formations.

"Hydraulic fracturing is a common stimulation technique used to enhance production of fluids from subterranean hydrocarbon formations. Hydraulic fracturing is used to stimulate low permeability formations where recovery efficiency is limited.

"During hydraulic fracturing, a fracturing fluid is pumped at high pressures and high rates into a wellbore penetrating a subterranean hydrocarbon formation to initiate and propagate a fracture in the formation. Well productivity depends on the ability of the fracture to conduct fluids from the formation to the wellbore. The treatment design generally requires the fluid to reach maximum viscosity as it enters the fracture which affects the fracture length and width. The requisite viscosity is generally obtained by the gelation of viscosifying polymers and/or surfactants in the fracturing fluid. The gelled fluid is accompanied by a proppant which results in placement of the proppant within the produced fracture.

"Once the fracture is initiated, subsequent stages of fracturing fluid containing proppant are pumped into the created fracture. The fracture generally continues to grow during pumping and the proppant remains in the fracture in the form of a permeable 'pack' that serves to 'prop' the fracture open. Once the treatment is completed, the fracture closes onto the proppants which maintain the fracture open, providing a highly conductive pathway for hydrocarbons and/or other formation fluids to flow into the wellbore.

"Filtrate from the fracturing fluid ultimately 'leaks off' into the surrounding formation leaving a filter cake comprised of fluid additives. Such additives, including the viscosifying polymers and/or surfactants used to provide fluid viscosity, are typically too large to penetrate the permeable matrix of the formation. Recovery of the fracturing fluid is therefore an important aspect to the success of the fracturing treatment.

"Recovery of the fracturing fluid is normally accomplished by reducing the viscosity of the fracturing fluid (breaking) such that the fracturing fluid flows naturally from the formation under the influence of formation fluids and pressure. Conventional oxidative breakers react rapidly at elevated temperatures, potentially leading to catastrophic loss of proppant transport. Encapsulated oxidative breakers have experienced limited utility at elevated temperatures due to a tendency to release prematurely or to have been rendered ineffective through payload self-degradation prior to release. Thus, the use of breakers in fracturing fluids at elevated temperatures, i.e., above about 120-130.degree. F., typically compromises proppant transport and desired fracture conductivity, the latter being measured in terms of effective propped fracture length. Improvements in hydraulic fracturing techniques are required in order to increase the effective propped fracture length and thereby improve stimulation efficiency and well productivity.

"Recently, fluids (such as water, salt brine and slickwater) which do not contain a viscosifying polymer have been used in the stimulation of tight gas reservoirs as hydraulic fracturing fluids. Such fluids are much cheaper than conventional fracturing fluids containing a viscosifying polymer and/or gelled or gellable surfactant. In addition, such fluids introduce less damage into the formation in light of the absence of a viscosifying polymer and/or surfactant in the fluid.

"The inherent properties of fluids not containing a viscosifying polymer, such as slickwater, present however several difficulties. Foremost, such fluids provide poor proppant transport as well as poor fluid efficiency (leakoff control). Further, the low viscosity of fluids like water, salt brine and slickwater makes it difficult, if not impossible, to generate the desired fracture width. This affects the requisite conductivity of the propped fracture as proppant placement in the fracture is often not possible.

"It is therefore desirable to use fluids that do not contain a viscosifying polymer, but which can provide proppant transport and which can also facilitate the extraction of hydrocarbons from the subterranean formation."

In addition to the background information obtained for this patent application, VerticalNews journalists also obtained the inventors' summary information for this patent application: "Disclosed herein is a nanoparticle modified fluid that comprises nanoparticles; and a liquid carrier; where the nanoparticles have their surfaces modified so as to increase the viscosity of the nanoparticle modified fluid above that of a comparative nanoparticle modified fluid that contains the same nanoparticles whose surfaces are not modified, when both nanoparticle modified fluids are tested at the same shear rate and temperature.

"Disclosed herein too is a method comprising mixing nanoparticles with a liquid carrier to form a nanoparticle modified fluid; where the nanoparticles have their surfaces modified so as to increase the viscosity of the nanoparticle modified fluid above that of a comparative nanoparticle modified fluid that contains the same nanoparticles whose surfaces are not modified, when both nanoparticle modified fluids are tested at the same shear rate and temperature.

"Disclosed herein too is a method of using a nanoparticle modified fluid comprising injecting into a subterranean hydrocarbon formation the nanoparticle modified fluid; contacting the subterranean hydrocarbon formation with the nanoparticle modified fluid; where the reduction in flow rate of the nanoparticle modified fluid as it contacts the formation promotes an increase in the viscosity of the nanoparticle modified fluid to a point of gelation; and injecting additional nanoparticle modified fluid into channels formed in the gelled nanoparticle modified fluid in the subterranean hydrocarbon formation.

BRIEF DESCRIPTION OF THE FIGURES

"FIG. 1 is a graph depicting the viscosity versus the shear rate for a nanoparticle modified fluid."

URL and more information on this patent application, see: Chakraborty, Soma; Johnson, Michael H. Nanoparticle Modified Fluids and Methods of Manufacture Thereof. Filed October 10, 2012 and posted April 17, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=4846&p=97&f=G&l=50&d=PG01&S1=20140410.PD.&OS=PD/20140410&RS=PD/20140410

Keywords for this news article include: Hydrocarbons, Nanoparticle, Nanotechnology, Organic Chemicals, Emerging Technologies, Baker Hughes Incorporated.

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Source: Politics & Government Week