Methods may include emplacing a downhole tool within a wellbore, sampling a fluid downhole with the downhole tool; analyzing the fluid, and calculating an interfacial tension (IFT), wherein calculating the acid-base IFT contribution comprises measuring a concentration of a surface-active species directly. Apparatuses for measuring an interfacial tension (IFT) in a fluid downhole may be part of a downhole tool and may include a sampling head to sample the fluid; and a downhole fluid analysis module that includes a spectrometer capable of measuring a concentration of a surface-active species in the fluid, and a processor configured to determine the IFT of the fluid downhole based on the measured concentration of the surface-active species.

A composite optical fiber is provided for permitting sensing of multiple parameters. The optical fiber is for incorporation into a sensing system, the optical fiber comprising: a single mode optical fiber core, a multimode optical fiber core, and an optical fiber cladding layer surrounding the single mode optical fiber core and the multimode optical fiber core. The optical fiber provided preferably enables multiple sensing and/or measurements to take place at a single location and at a single time.

Provided is a well system, and a related method. The well system, in one aspect, includes a wellbore extending through first and second subterranean hydrocarbon producing zones, as well as a feedthrough packer located in the wellbore, the feedthrough packer configured to help separate a first inflow of hydrocarbons from the first subterranean hydrocarbon producing zone through a first inflow control valve into production tubing from a second inflow of hydrocarbons from the second subterranean hydrocarbon producing zone through a second inflow control valve into the production tubing. The well system, in accordance with this aspect, may further include a fiber optic cable installed across the feedthrough packer, the fiber optic cable configured to collect inflow data from the first subterranean hydrocarbon producing zone or the second subterranean hydrocarbon producing zone.

A downhole tool system includes a downhole tool that includes a tool body configured to move within a wellbore, a depth detection sub-assembly and configured to generate a signal based on a known depth location of the tool body in the wellbore, an acoustic transmitter sub-assembly including an acoustic pinger configured to generate acoustic pulses, and a measurement and control sub-assembly configured to receive the signal from the depth detection sub-assembly and, based on the signal, activate the acoustic transmitter sub-assembly to initiate the acoustic pulses from the acoustic pinger. The system further includes a control system that includes a fiber optic interrogator communicably coupled to a fiber strand installed in the wellbore and configured to determine a travel time of the tool body along the fiber strand or a particular distributed acoustic sensing (DAS) channel of a plurality of DAS channels based on a detection of at least one disturbance in the fiber strand caused by the acoustic pulses.

The present disclosure is directed to articles that include a cured coating that includes a matrix of crosslinked polymers and optionally a colorant (e.g., pigment particles or dye or both). The cured coating can include a matrix of crosslinked polymers. The cured coating is a product of crosslinking a coating composition comprising uncrosslinked polymers (e.g., a dispersion of uncrosslinked polymers in a carrier to form the matrix of crosslinked polymers), wherein the uncrosslinked polymers are crosslinked to form the matrix of crosslinked polymers. The matrix of crosslinked polymers can be elastomeric. The present disclosure is also directed to articles including these bladders, methods of forming these bladders, and methods of making articles including these bladders, where the bladders include the cured coating.

The present disclosure is directed to articles that include one or more coated fiber(s) (i.e., fiber(s) with a cured coating disposed thereon), where the coating includes a matrix of crosslinked polymers and optionally a colorant (e.g., pigment particles or dye or both). The cured coating is a product of crosslinking a coating composition including uncrosslinked polymers (e.g., a dispersion of uncrosslinked polymers in a carrier, wherein the uncrosslinked polymers are crosslinked to form the matrix of crosslinked polymers). The present disclosure is also directed to articles including the coated fibers, methods of forming the coated fibers and articles, and methods of making articles including the coated fibers.

There are described methods, systems, and computer-readable media for detecting events in a conduit. Multiple lengths of optical fiber positioned alongside a conduit are used to detect a signal. For each length of optical fiber, interferometric data is obtained from the detected signal. The interferometric data obtained for one length of optical fiber is compared to the interferometric data obtained for one or more other lengths of optical fiber. Based on the comparison, it is determined whether the signal originated from the conduit.

A method for controlling a flow of one or more fluids from a formation into a production tubing, includes measuring fluid properties of the one or more fluids passing through one or more fluidic oscillators of a flowmeter device disposed on the production tubing, adjusting the flow in a flow area based on the fluid properties through an inflow control device coupled to the production tubing and is in fluid communication with the flow meter device, and controlling, in response to change in the fluid properties, actuation of the inflow control device to adjust the flow by a controller coupled to the inflow control device.

A composite optical fiber is provided for permitting sensing of multiple parameters. The optical fiber is for incorporation into a sensing system, the optical fiber comprising: a single mode optical fiber core, a multimode optical fiber core, and an optical fiber cladding layer surrounding the single mode optical fiber core and the multimode optical fiber core. The optical fiber provided preferably enables multiple sensing and/or measurements to take place at a single location and at a single time.

A downhole monitoring system for continuously measuring in real-time a fluid produced from a reservoir includes a tubing extending into a wellbore, spaced apart packers forming annular seals between the tubing and a wall of the wellbore, isolated compartments formed between the spaced apart packers, each compartment having an opening in the tubing to allow fluid communication from the reservoir to surface equipment, and an ultraviolet spectrometer installed in each compartment. The ultraviolet spectrometer includes an ultra-violet source that excites diamondoids, a photomultiplier to quantify the excited diamondoids, and an electronic circuit that digitizes a response from the photomultiplier and sends the response to the surface of the wellbore. Additionally, a method includes continuously monitoring and in real-time a fluid produced from a reservoir and determining reservoir connectivity and reservoir profiling.