Abstract: Optical fiber having a graphene coating, a method to apply a graphene coating onto an optical fiber, and a fiber optic cable having a graphene coating are disclosed. A first carbon based coating is applied to an optical fiber along a longitudinal axis of the optical fiber. A laser beam is focused at the first carbon based coating. A first surface of the first carbon based coating is photothermally converted into a first layer of graphene.

Abstract: Systems and methods are provided for applying a protective graphene barrier to waveguides and using the protected waveguides in wellbore applications. A well monitoring system may comprise a waveguide comprising a graphene barrier, wherein the graphene barrier comprises at least one material selected from the group consisting of graphene, graphene oxide, and any combination thereof; a signal generator capable of generating a signal that travels through the waveguide; and a signal detector capable of detecting a signal that travels through the waveguide.

Abstract: In some embodiments, a method and apparatus, as well as an article, may operate to determine downhole properties based on detected optical signals. An optical detection apparatus can include an optical detector including a superconducting nanowire single photon detector (SNSPD) for detecting light received at an input section of fiber optic cable. The optical detection apparatus can further include a cryogenic cooler configured to maintain the temperature of a light-sensitive region of the SNSPD within a superconducting temperature range of the SNSPD. Downhole properties are measured based on detected optical signals received at the optical detection apparatus. Additional apparatus, systems, and methods are disclosed.

Abstract: A method and system are disclosed that provide chemical composition data of a fluid. The system includes a first downhole electro-opto-mechanical device to transmit microwave radiation through the fluid. The microwave radiation is generated by the first downhole electro-opto-mechanical device in response to a first light signal. A second downhole electro-opto-mechanical device receives the microwave radiation and generates a second light signal in response to the received microwave radiation. A light detection device is coupled to the second downhole electro-opto-mechanical device to generate an electrical signal in response to the second light signal. The electrical signal is indicative of the chemical composition of the fluid.

Abstract: The present disclosure relates generally to a system and method for increasing the reliability and data-rate transmission of information from a downhole device to the surface and from the surface to the downhole device. A fluid sampling system may comprise a downhole tool positionable in a wellbore and comprising a fluid testing chamber. The downhole tool may also comprise a light spectrum analysis unit disposed at a surface of the wellbore, wherein the light spectrum analysis unit comprises a detector. The downhole tool may further comprise a fiber optic cable for carrying light from the downhole tool to the light spectrum analysis unit, wherein the fiber optic cable is connected to the downhole tool and the light spectrum analysis unit.

Abstract: In some embodiments, a method and apparatus, as well as an article, may operate to determine downhole properties based on detected optical signals. An optical detection apparatus can include an optical detector including a superconducting nanowire single photon detector (SNSPD) for detecting light received at an input section of fiber optic cable. The optical detection apparatus can further include a cryogenic cooler configured to maintain the temperature of a light-sensitive region of the SNSPD within a superconducting temperature range of the SNSPD. Downhole properties are measured based on detected optical signals received at the optical detection apparatus. Additional apparatus, systems, and methods are disclosed.

Abstract: In some embodiments, a method and apparatus, as well as an article, may operate to determine properties based on detected optical signals. An optical detection apparatus can include an optical detector for detecting light received through a fiber optic cable; a housing for enclosing the optical detector; a light source; and a cooling mechanism having the housing mounted thereto. The cooling mechanism can maintain the temperature of a light-sensitive region of the optical detector within a temperature range below 210 degrees Kelvin. Additional apparatus, systems, and methods are disclosed.

Abstract: Disclosed herein are methods and systems that use magnetic complexes in wellbore monitoring. A well monitoring system may comprise magnetic complexes disposed in a subterranean formation, wherein the magnetic complexes each comprise a first magnetic portion, a second magnetic portion, and a spacer portion; and an electromagnetic interrogator, wherein the electromagnetic interrogator comprises an electromagnetic source and an electromagnetic detector.

Abstract: A system, method, and device for determining volume concentration with diffraction of electromagnetic radiation. A device for determining a volume concentration of a fluid in a sample comprises a transducer, a transmitter, a detector, and a processor. The transducer generates a standing acoustic wave through the sample. The transmitter emits electromagnetic (EM) radiation into the sample such that the EM radiation is diffracted by the sample. The detector is responsive to the diffracted EM radiation and generates a signal indicative of a wavelength of an acoustic wave corresponding to the standing acoustic wave. The processor analyzes the signal to determine the volume concentration of the fluid in the sample.

Abstract: Systems and methods for terahertz modulation in a terahertz frequency band from about 0.1 terahertz to about 10 terahertz propagating in a wellbore intersecting a subterranean earth formation. A transmitter generates the EM radiation in the terahertz frequency band. A modulator located in the wellbore receives the EM radiation and generates an amplitude modulated signal with the EM radiation.

Abstract: In some embodiments, a method and apparatus, as well as an article, may operate to determine downhole properties based on detected optical signals. An optical detection system can include a fiber optic cable having a sensing location to generate a reflected measurement signal representative of measurement parameters. The optical detection system can further include a light source to transmit a measurement signal to cause the sensing location to provide the reflected measurement signal. The optical detection system can further include an optical detector comprising a single-photon detector (SPD) for detecting the reflected measurement signal received over the fiber optic cable. The optical detection system can further include a housing for enclosing the optical detector and to optically shield the optical detector, the housing including an aperture for passage of the fiber optic cable. Additional apparatuses, systems, and methods are disclosed.

Abstract: A system and method for making measurements inside a wellbore makes use of a diamond crystal with a nitrogen vacancy center (NV-center) to sense temperature, pressure, magnetic fields, strain, electric fields, or other parameters of the downhole environment. The system includes a microwave source that can be positioned to produce microwaves inside the wellbore and a light source that can be positioned to produce interrogation light inside the wellbore. The NV-center of the diamond is struck by the interrogation light. A spectrometer can be adapted to receive the excitation light output from the NV-center and produce a spectrum of the excitation light. The spectrum is indicative of the value of the parameter inside the wellbore.

Abstract: Optical fiber having a graphene coating, a method to apply a graphene coating onto an optical fiber, and a fiber optic cable having a graphene coating are disclosed. A first carbon based coating is applied to an optical fiber along a longitudinal axis of the optical fiber. A laser beam is focused at the first carbon based coating. A first surface of the first carbon based coating is photothermally converted into a first layer of graphene.

Abstract: The disclosed embodiments include an optical fiber having a graphene coating, a method to apply a graphene coating onto an optical fiber, and a fiber optic cable having a graphene coating. In one embodiment, the optical fiber includes an optical core that extends along a longitudinal axis. The optical fiber also includes a carbon based coating that covers the optical core along the longitudinal axis. The optical fiber also includes a layer of graphene formed on a first surface of the carbon based coating. The layer of graphene is formed from a laser induction process that includes focusing a laser beam at the carbon based coating to photothermally convert the first surface of the carbon based coating into graphene.

Abstract: The present disclosure relates generally to a system and method for increasing the reliability and data-rate transmission of information from a downhole device to the surface and from the surface to the downhole device. A fluid sampling system may comprise a downhole tool positionable in a wellbore and comprising a fluid testing chamber. The downhole tool may also comprise a light spectrum analysis unit disposed at a surface of the wellbore, wherein the light spectrum analysis unit comprises a detector. The downhole tool may further comprise a fiber optic cable for carrying light from the downhole tool to the light spectrum analysis unit, wherein the fiber optic cable is connected to the downhole tool and the light spectrum analysis unit.

Abstract: The disclosed embodiments include an optical fiber having a graphene coating, a method to apply a graphene coating onto an optical fiber, and a fiber optic cable having a graphene coating. In one embodiment, the optical fiber includes an optical core that extends along a longitudinal axis. The optical fiber also includes a carbon based coating that covers the optical core along the longitudinal axis. The optical fiber also includes a layer of graphene formed on a first surface of the carbon based coating. The layer of graphene is formed from a laser induction process that includes focusing a laser beam at the carbon based coating to photothermally convert the first surface of the carbon based coating into graphene.

Abstract: A system and method for making measurements inside a wellbore makes use of a diamond crystal with a nitrogen vacancy center (NV-center) to sense temperature, pressure, magnetic fields, strain, electric fields, or other parameters of the downhole environment. The system includes a microwave source that can be positioned to produce microwaves inside the wellbore and a light source that can be positioned to produce interrogation light inside the wellbore. The NV-center of the diamond is struck by the interrogation light. A spectrometer can be adapted to receive the excitation light output from the NV-center and produce a spectrum of the excitation light. The spectrum is indicative of the value of the parameter inside the wellbore.

Abstract: The present disclosure relates to systems and methods for analyzing fluids. The method for analyzing a chemical sample within a wellbore, contained within an interrogation device, may comprise broadcasting a coherent light from a frequency comb module, directing the coherent light through a fiber optic line to the interrogation device, irradiating the chemical sample with the coherent light, capturing light resulting from the irradiation of the chemical sample, and producing a spectrum resulting from the captured light from the chemical sample. A frequency comb system for analyzing a chemical sample may comprise a frequency comb module configured to broadcast a coherent light and a fiber optic line that extends into a wellbore to an interrogation device. The interrogation device may further be configured to contain the chemical sample for irradiation by the coherent light. The frequency comb system may further comprise a receiver and an information handling system.

Abstract: Disclosed herein are methods and systems that use magnetic complexes in wellbore monitoring. A well monitoring system may comprise magnetic complexes disposed in a subterranean formation, wherein the magnetic complexes each comprise a first magnetic portion, a second magnetic portion, and a spacer portion; and an electromagnetic interrogator, wherein the electromagnetic interrogator comprises an electromagnetic source and an electromagnetic detector.

Abstract: Gravity surveys of subterranean formations may be based on the simultaneous measurement of gravity and its derivatives to produce a higher resolution formation map or wellbore log.