Abstract: Methods and systems for generating a nanofluidic chip as a reservoir model are provided. In an example described herein, a nanofluidic chip for reservoir modeling includes a microfluidic chip that includes microchannels etched in a substrate. Silica spheres are assembled in the microchannels to form nanochannels. A carbonate coating is disposed over the surfaces of the nano channels and the silica spheres.

Abstract: The disclosure features methods of analyzing a fluid extracted from a reservoir, the methods including introducing a first composition featuring a first complexing agent into a reservoir at a first location, extracting a fluid from the reservoir at a second location different from the first location, combining the fluid with a second composition featuring a concentration of a lanthanide ion to form a third composition featuring a concentration of a complex formed by the first complexing agent and the lanthanide ion, exposing a quantity of the complex to electromagnetic radiation for a first time period ending at a time t0, detecting fluorescence emission from the quantity of the complex for a second time period starting at a time t1>t0, where t0?t0 is greater than 2 microseconds, and determining information about a fluid flow path between the first location and the second location.

Abstract: Spherical grains and sacrificial particles are mixed in a suspension. The sacrificial particles are larger than the spherical grains. The suspension is injected into a channel in a microfluidic chip, and the spherical grains form microporous structures in the channel. The microporous structures are sintered in the channel. A solvent is injected into the channel, and the solvent dissolves the sacrificial particles and forms macropores between at least some of the microporous structures, thereby forming a mixed-porosity microfluidic chip.

Abstract: Enhanced oil recovery (EOR) including with a lamellar phase having Janus nanoparticles, petroleum surfactant, crude oil, and water and with additional water to give the flooding fluid that may be pumped through a wellbore into a subterranean formation to affect a property of hydrocarbon in the subterranean formation via contact of the flooding fluid with the hydrocarbon.

Abstract: Compositions and methods for determining the origin location of a subterranean sample are provided. Compositions include a nanoparticle tag including a superparamagnetic iron oxide core, an intermediate layer including a fluorescent dye, and a polymer shell. The nanoparticles can be synthesized by functionalizing a superparamagnetic iron oxide nanoparticle core and covalently bonding a fluorescent dye to the functionalized nanoparticle core. In some implementations, a polymer is covalently bonded to the functionalized, fluorescent superparamagnetic iron oxide nanoparticle core. The nanoparticle tag can be used to determine the origin location of a subterranean sample by mixing the nanoparticle tag into a fluid, flowing the fluid into a subterranean formation, recovering subterranean samples from the subterranean formation, and separating tagged samples from untagged samples using a magnet.

Abstract: The disclosure features methods of analyzing a fluid extracted from a reservoir, the methods including introducing a first composition featuring a first complexing agent into a reservoir at a first location, extracting a fluid from the reservoir at a second location different from the first location, combining the fluid with a second composition featuring a concentration of a lanthanide ion to form a third composition featuring a concentration of a complex formed by the first complexing agent and the lanthanide ion, exposing a quantity of the complex to electromagnetic radiation for a first time period ending at a time t0, detecting fluorescence emission from the quantity of the complex for a second time period starting at a time t1>t0, where t1?t0 is greater than 2 microseconds, and determining information about a fluid flow path between the first location and the second location.

Abstract: Enhanced oil recovery (EOR) including with a lamellar phase having Janus nanoparticles, petroleum surfactant, crude oil, and water and with additional water to give the flooding fluid that may be pumped through a wellbore into a subterranean formation to affect a property of hydrocarbon in the subterranean formation via contact of the flooding fluid with the hydrocarbon.

Abstract: Compositions and methods for determining the origin location of a subterranean sample are provided. Compositions include a nanoparticle tag including a superparamagnetic iron oxide core, an intermediate layer including a fluorescent dye, and a polymer shell. The nanoparticles can be synthesized by functionalizing a superparamagnetic iron oxide nanoparticle core and covalently bonding a fluorescent dye to the functionalized nanoparticle core. In some implementations, a polymer is covalently bonded to the functionalized, fluorescent superparamagnetic iron oxide nanoparticle core. The nanoparticle tag can be used to determine the origin location of a subterranean sample by mixing the nanoparticle tag into a fluid, flowing the fluid into a subterranean formation, recovering subterranean samples from the subterranean formation, and separating tagged samples from untagged samples using a magnet.

Abstract: Synthesizing Janus material including forming a lamellar phase having water layers and organic layers, incorporating nanosheets and a functional agent into the lamellar phase, and attaching the functional agent to the nanosheets in the lamellar phase to form Janus nanosheets.

Abstract: A method includes introducing into a drilling fluid a plurality of tags having a first clay nanoparticle and a first polymer embedded into the clay nanoparticle and circulating the drilling fluid and tags through a well during a drilling operation that creates formation cuttings such that the tags interact with the formation cuttings, creating tagged cuttings. The returned cuttings are collected from the circulating drilling fluid at a surface of the well, and the tags on the returned cuttings are detected to identify the tagged cuttings. The method also includes correlating the tagged cuttings with a drill depth in the well from the drilling operation.

Abstract: The disclosure features methods of analyzing a fluid extracted from a reservoir, the methods including introducing a first composition featuring a first complexing agent into a reservoir at a first location, extracting a fluid from the reservoir at a second location different from the first location, combining the fluid with a second composition featuring a concentration of a lanthanide ion to form a third composition featuring a concentration of a complex formed by the first complexing agent and the lanthanide ion, exposing a quantity of the complex to electromagnetic radiation for a first time period ending at a time to, detecting fluorescence emission from the quantity of the complex for a second time period starting at a time t1>t0, where t1?t0 is greater than 2 microseconds, and determining information about a fluid flow path between the first location and the second location.

Abstract: Optical properties of a tracer in water are measured at varying concentrations. A reference curve is built based on the measured optical properties at varying concentrations. An emulsion is mixed with the tracer. The emulsion is demulsified into an oil component and an aqueous component. Optical properties of one of the components are measured. A partition coefficient is determined based on the measured optical properties of a demulsified component and the reference curve.

Abstract: Compositions and methods for extracting tracers from subterranean fluids are provided. The compositions include a media for solid phase extraction. The media includes a homogenous mixture of a first and second sorbent. The first sorbent includes a crosslinked polystyrene divinyl benzene copolymer core functionalized with hydroxylated polystyrene divinyl benzene copolymer. The second sorbent includes a crosslinked polystyrene divinyl benzene core functionalized with a copolymer that includes secondary and tertiary amino groups. A solid phase extraction cartridge including a homogenous mixture of the first and second sorbent is also provided. Methods of extracting tracers from subterranean fluids include extracting the tracers with a solid phase extraction column that includes a homogenous mixture of the first and second sorbent.

Abstract: A blocking material is injected into a microfluidic chip that includes microscale-porosity microchannels etched in a substrate, filling at least a portion of the microchannels. Silicon dioxide spheres are injected into the microfluidic chip. The blocking material prevents the silicon dioxide spheres from entering the portion of the microchannels filled with the blocking material. The silicon dioxide spheres form a region of nanoscale porosity in a portion of the microchannels not filled with the blocking material. A solvent is injected into the microfluidic chip, the solvent operable to dissolve the blocking material and thereby providing a region of microscale porosity adjacent to the region of nanoscale porosity.

Abstract: Compositions and methods for determining the origin location of a subterranean rock sample. Compositions include a nanoparticle tag with a fluorescent core and a polymer shell. The fluorescent core can include up-converting nanoparticles, rare earth element doped oxide, long persistent fluorescent materials, or encapsulated lanthanide complexes. Methods include mixing a nanoparticle tag into a fluid, flowing the fluid through a work string into a subterranean formation, recovering subterranean rock samples from the subterranean formation, and determining an origin location of the subterranean rock sample by detecting the presence of the nanoparticle tag on the sample.

Abstract: A method includes introducing into a drilling fluid a plurality of tags having a first clay nanoparticle and a first polymer embedded into the clay nanoparticle and circulating the drilling fluid and tags through a well during a drilling operation that creates formation cuttings such that the tags interact with the formation cuttings, creating tagged cuttings. The returned cuttings are collected from the circulating drilling fluid at a surface of the well, and the tags on the returned cuttings are detected to identify the tagged cuttings. The method also includes correlating the tagged cuttings with a drill depth in the well from the drilling operation.

Abstract: Compositions and methods for determining the origin location of a subterranean sample are provided. Compositions include a nanoparticle tag including a superparamagnetic iron oxide core, an intermediate layer including a fluorescent dye, and a polymer shell. The nanoparticles can be synthesized by functionalizing a superparamagnetic iron oxide nanoparticle core and covalently bonding a fluorescent dye to the functionalized nanoparticle core. In some implementations, a polymer is covalently bonded to the functionalized, fluorescent superparamagnetic iron oxide nanoparticle core. The nanoparticle tag can be used to determine the origin location of a subterranean sample by mixing the nanoparticle tag into a fluid, flowing the fluid into a subterranean formation, recovering subterranean samples from the subterranean formation, and separating tagged samples from untagged samples using a magnet.

Abstract: Compositions and methods for determining the origin location of subterranean rock samples. In some implementations, the compositions include a nanoparticle tag that includes a natural polysaccharide, a fluorescent dye, and superparamagnetic nanoparticles. In some implementations, a method of determining the origin location of a subterranean rock sample includes mixing the nanoparticle tag into a fluid, flowing the fluid into a subterranean formation, recovering subterranean rock samples from the formation, separating tagged rock samples from untagged rock samples using a magnet, and determining the origin location by analyzing a fluorescent signal of the nanoparticle tag.

Abstract: Compositions and methods for determining the origin location of a subterranean sample are provided. Compositions include a polymer-clay composite tag. The tag includes a nanoclay including a plurality of layers, and a polymer intercalated between the layers of the nanoclay. The polymer is functionalized with a fluorescent dye. A method to determine the origin location of a subterranean sample includes mixing a barcoded polymer-clay composite tag into a fluid, flowing the fluid through a work string into a subterranean formation, recovering subterranean samples from the subterranean formation, and determining the origin location of the subterranean sample by detecting the presence of the barcoded polymer-clay composite tag.

Abstract: Systems and methods for analyzing groundwater samples with multiple organic tracer species from a petroleum containing reservoir include obtaining the sample, isolating an aqueous fraction of the groundwater sample, separating the aqueous fraction into a plurality of components, where each component corresponds to a different one of the organic tracer species, combining each of the separated components with at least one lanthanide element to form a plurality of component solutions, where a ratio of the at least one lanthanide element to the separated component in each component solution is 5:1 or greater, and analyzing each component solution to determine a relative amount of each organic tracer species in the groundwater sample.