Abstract: A method includes injecting an injection fluid through a well and to a depth of a formation, where the injection fluid includes phase-changing nanodroplets having a liquid core and a shell. The method also includes exposing the phase-changing nanodroplets to an external stimulus at the depth of the formation, wherein the liquid core of the phase-changing nanodroplets undergoes a liquid-to-vapor phase change causing the phase-changing nanodroplets to expand, and stimulating the formation at a near wellbore region by expansion of the phase-changing nanodroplets.

Abstract: A polymer gel may comprise a polymer gel base material and superparamagnetic nanoparticles. At least 25 wt. % of the superparamagnetic nanoparticles may have diameters in a first size range between a first diameter and a second diameter. At least 25 wt. % of the superparamagnetic nanoparticles may have diameters in a second size range between a third diameter and a fourth diameter. The Brownian relaxation time of the portion of the superparamagnetic nanoparticles in the first size range may be at least 5 times the Neel relaxation time of the portion of the superparamagnetic nanoparticles in the first size range. The Neel relaxation time of the portion of the superparamagnetic nanoparticles in the second size range may be at least 5 times the Brownian relaxation time of the portion of the superparamagnetic nanoparticles in the second size range. Methods for monitoring gel integrity in a wellbore are further included.

Abstract: Subsurface environments can be characterized using photoacoustic nanotracers. A solution including a photoacoustic nanotracer is formed. The solution is injected into the subsurface environment. Produced fluids are analyzed for the photoacoustic nanotracer. A breakthrough curve is built based, at least in part, on the analysis. The photoacoustic nanotracers can be based on plasmonic gold nanoparticles, silver nanoparticles, or both.

Abstract: A method includes injecting an injection fluid through a well and to a depth of a formation, where the injection fluid includes phase-changing nanodroplets having a liquid core and a shell. The method also includes exposing the phase-changing nanodroplets to an external stimulus at the depth of the formation, wherein the liquid core of the phase-changing nanodroplets undergoes a liquid-to-vapor phase change causing the phase-changing nanodroplets to expand, and stimulating the formation at a near wellbore region by expansion of the phase-changing nanodroplets.

Abstract: A downhole composition includes a carrier fluid and at least one shape-changing nanoparticle. The shape-changing nanoparticle is configured to change shape upon exposure to elevated temperature for a period of time. A method of monitoring temperature in a reservoir is provided. The method includes introducing a temperature monitoring composition into the reservoir, the temperature monitoring composition including a carrier fluid and at least one shape-changing nanoparticle. Then, after a predetermined period, producing a produced fluid from the reservoir, collecting samples of the produced fluid, measuring an optical property of the shape-changing nanoparticle, and based on the measured property of the shape-changing nanoparticle, determining a temperature of at least a portion of the reservoir.

Abstract: A tracer composition includes a carrier fluid and a tracer particle that includes at least one magnetic material and an acoustic signal generating material. A method includes introducing a tracer composition into a reservoir at a first location. The method further includes collecting fluid from the reservoir at a second location, where the first location is different from the second location. The method also includes applying a magnet field to the fluid collected from the reservoir such that the magnetic material produces vibrational energy. Due to the vibrational energy generated in the magnetic material, thermal energy is transferred to the acoustic signal generating material thereby heating the acoustic signal generating material to a boiling point such that the acoustic signal is generated. The method further includes detecting the acoustic signal and correlating the acoustic signal to a tracer particle concentration.

Abstract: A polymer gel may comprise a polymer gel base material and superparamagnetic nanoparticles. At least 25 wt. % of the superparamagnetic nanoparticles may have diameters in a first size range between a first diameter and a second diameter. At least 25 wt. % of the superparamagnetic nanoparticles may have diameters in a second size range between a third diameter and a fourth diameter. The Brownian relaxation time of the portion of the superparamagnetic nanoparticles in the first size range may be at least 5 times the Neel relaxation time of the portion of the superparamagnetic nanoparticles in the first size range. The Neel relaxation time of the portion of the superparamagnetic nanoparticles in the second size range may be at least 5 times the Brownian relaxation time of the portion of the superparamagnetic nanoparticles in the second size range. Methods for monitoring gel integrity in a wellbore are further included.

Abstract: A method includes injecting an aqueous-based injection fluid into a wellbore at a first temperature, where the aqueous-based injection fluid includes phase-changing nanodroplets having a liquid core and a shell. The method also includes exposing the phase-changing nanodroplets to a second temperature in the wellbore that is greater than or equal to a boiling point of the liquid core to change a liquid in the liquid core to a vapor phase and expand the phase-changing nanodroplets, thus removing debris from the wellbore and surrounding area.

Abstract: A polymer gel may comprise a polymer gel base material and superparamagnetic nanoparticles. At least 25 wt. % of the superparamagnetic nanoparticles may have diameters in a first size range between a first diameter and a second diameter. At least 25 wt. % of the superparamagnetic nanoparticles may have diameters in a second size range between a third diameter and a fourth diameter. The Brownian relaxation time of the portion of the superparamagnetic nanoparticles in the first size range may be at least 5 times the Neel relaxation time of the portion of the superparamagnetic nanoparticles in the first size range. The Neel relaxation time of the portion of the superparamagnetic nanoparticles in the second size range may be at least 5 times the Brownian relaxation time of the portion of the superparamagnetic nanoparticles in the second size range. Methods for monitoring gel integrity in a wellbore are further included.

Abstract: A downhole composition includes a carrier fluid and at least one shape-changing nanoparticle. The shape-changing nanoparticle is configured to change shape upon exposure to elevated temperature for a period of time. A method of monitoring temperature in a reservoir is provided. The method includes introducing a temperature monitoring composition into the reservoir, the temperature monitoring composition including a carrier fluid and at least one shape-changing nanoparticle. Then, after a predetermined period, producing a produced fluid from the reservoir, collecting samples of the produced fluid, measuring an optical property of the shape-changing nanoparticle, and based on the measured property of the shape-changing nanoparticle, determining a temperature of at least a portion of the reservoir.

Abstract: A single well chemical tracer composition comprising core/shell tracer particles and an aqueous fluid is provided. The core/shell tracer particles have a core and a polymer shell. At least two tracer chemicals are encapsulated in the core/shell tracer particles. A method of determining residual oil in a reservoir is also provided. The method includes introducing a tracer fluid having the core/shell tracer particles into a wellbore. The reservoir is then maintained for a period of time such that the core/shell particle is ruptured, and the tracer chemicals are released into the reservoir. Then, the method includes producing a produced fluid from the reservoir, measuring the quantity of the tracer chemicals in the produced fluid, and determining a residual oil content of the reservoir based on the measured quantity of the tracer chemicals in the produced fluid.

Abstract: Provided is an injection fluid that may include a nanoemulsion having an oil phase dispersed in an aqueous phase, and non-superparamagnetic magnetic nanoparticles that are present in the dispersed oil phase. Further provided is a method for preparing an injection fluid that may include preparing a nanoemulsion from an aqueous phase and an oil phase having non-superparamagnetic magnetic nanoparticles therein, and may be used to form nanodroplets of the non-superparamagnetic magnetic nanoparticles. Further provided is a method for tracking movement of an injection fluid. The method may include introducing a tagged injection fluid into a hydrocarbon-containing reservoir, the tagged injection fluid may be a nanoemulsion that includes: an aqueous phase, an oil phase dispersed in the aqueous phase, and non-superparamagnetic nanoparticles that are present in the dispersed oil phase; and tracking the movement of the tagged injection fluid.

Abstract: A variable-frequency light source is configured to emit a light beam and modulate a frequency of the light beam. A fiber optic cable is attached to the variable frequency light source. The fiber optic cable is configured to receive the light beam at an inlet and pass the light beam to an exit. Multiple optical detectors are attached to the fiber optic cable. Each of the optical detectors is configured to detect a specified frequency of light that is backscattered through the fiber optic cable. An actuation mechanism is attached to the fiber optic cable. The actuation mechanism is configured to deform the fiber optic cable in response to a stimulus.

Abstract: A method and a system for characterizing subsurface environments using photoacoustic nanotracers are provided herein. An exemplary method for using a photoacoustic nanotracer to characterize a subsurface environment includes forming a solution including a photoacoustic nanotracer, injecting the solution into the subsurface environment, and analyzing produced fluids for the photoacoustic nanotracer. A breakthrough curve is built based, at least in part, on the analysis.

Abstract: Provided is an injection fluid that may include a nanoemulsion having an oil phase dispersed in an aqueous phase, and non-superparamagnetic magnetic nanoparticles that are present in the dispersed oil phase. Further provided is a method for preparing an injection fluid that may include preparing a nanoemulsion from an aqueous phase and an oil phase having non-superparamagnetic magnetic nanoparticles therein, and may be used to form nanodroplets of the non-superparamagnetic magnetic nanoparticles. Further provided is a method for tracking movement of an injection fluid. The method may include introducing a tagged injection fluid into a hydrocarbon-containing reservoir, the tagged injection fluid may be a nanoemulsion that includes: an aqueous phase, an oil phase dispersed in the aqueous phase, and non-superparamagnetic nanoparticles that are present in the dispersed oil phase; and tracking the movement of the tagged injection fluid.

Abstract: A polymer gel may comprise a polymer gel base material and superparamagnetic nanoparticles. At least 25 wt. % of the superparamagnetic nanoparticles may have diameters in a first size range between a first diameter and a second diameter. At least 25 wt. % of the superparamagnetic nanoparticles may have diameters in a second size range between a third diameter and a fourth diameter. The Brownian relaxation time of the portion of the superparamagnetic nanoparticles in the first size range may be at least 5 times the Neel relaxation time of the portion of the superparamagnetic nanoparticles in the first size range. The Neel relaxation time of the portion of the superparamagnetic nanoparticles in the second size range may be at least 5 times the Brownian relaxation time of the portion of the superparamagnetic nanoparticles in the second size range. Methods for monitoring gel integrity in a wellbore are further included.

Abstract: A variable-frequency light source is configured to emit a light beam and modulate a frequency of the light beam. A fiber optic cable is attached to the variable frequency light source. The fiber optic cable is configured to receive the light beam at an inlet and pass the light beam to an exit. Multiple optical detectors are attached to the fiber optic cable. Each of the optical detectors is configured to detect a specified frequency of light that is backscattered through the fiber optic cable. An actuation mechanism is attached to the fiber optic cable. The actuation mechanism is configured to deform the fiber optic cable in response to a stimulus.

Abstract: Provided are systems and methods for monitoring water cresting in a subsurface formation. Embodiments include, for each of a plurality of locations along a length of a horizontal section of a wellbore extending into a hydrocarbon reservoir of a subsurface formation, advancing an omnidirectional electromagnetic logging tool (ODEMLT) to the location, operating the ODEMLT to transmit (into a portion of the subsurface formation below the horizontal section of the wellbore) an electromagnetic (EM) source signal comprising a multi-frequency waveform, operating the ODEMLT to sense an EM return signal comprising a reflection of the multi-frequency waveform from the subsurface formation, and generating a subset of saturation data for the location corresponding to the sensed EM return signal, and generating, based on the subsets of saturation data, a radargram including a two-dimensional mapping of water saturation within the portion of the subsurface formation.

Abstract: A variable-frequency light source is configured to emit a light beam and modulate a frequency of the light beam. A fiber optic cable is attached to the variable frequency light source. The fiber optic cable is configured to receive the light beam at an inlet and pass the light beam to an exit. Multiple optical detectors are attached to the fiber optic cable. Each of the optical detectors is configured to detect a specified frequency of light that is backscattered through the fiber optic cable. An actuation mechanism is attached to the fiber optic cable. The actuation mechanism is configured to deform the fiber optic cable in response to a stimulus.

Abstract: A variable-frequency light source is configured to emit a light beam and modulate a frequency of the light beam. A fiber optic cable is attached to the variable frequency light source. The fiber optic cable is configured to receive the light beam at an inlet and pass the light beam to an exit. Multiple optical detectors are attached to the fiber optic cable. Each of the optical detectors is configured to detect a specified frequency of light that is backscattered through the fiber optic cable. An actuation mechanism is attached to the fiber optic cable. The actuation mechanism is configured to deform the fiber optic cable in response to a stimulus.