A method of generating a maintenance schedule for an aircraft including one or more gas turbine engines powered by an aviation fuel. The method includes: determining one or more fuel characteristics of the fuel; and generating a maintenance schedule according to the one or more fuel characteristics. Also disclosed is a method of maintaining an aircraft, a maintenance schedule generation system and an aircraft.

Disclosed herein are graphene quantum dot tagged paraffin suppressants such as graphene tagged paraffin inhibitors and paraffin dispersants and methods of making and using thereof. The graphene quantum dots are covalently bound to residues of paraffin inhibitors or dispersed with paraffin dispersants to form tagged paraffin suppressants active in inhibiting paraffin crystallization or dispersing crystalized paraffin wax in crude oils and compositions comprising crude oils. The dots can be tailored to fluoresce at wavelengths with minimized correspondence to the natural fluorescence of crude oils, enabling the measurement of the concentration of the paraffin suppressants in crude oils or compositions comprising crude oils. The tagged suppressants are used to trace the dispersion and disposition of the paraffin suppressants in oils and compositions comprising them, for example within crude-oil recovery, production, processing, or conveyance and transportation, by in situ sampling the oil or composition and measuring the fluorescence of the sampled material.

A method for measuring at least one property of a sample includes obtaining a sample of fluid including at least fines from a downhole environment, exposing the sample to a magnetic field, measuring a magnetic susceptibility of the fines in the sample in response to the magnetic field, and identifying at least one mineral present in the fines based at least partially on the magnetic susceptibility.

A device includes a housing having a bore formed axially therethrough. The housing includes a stop that protrudes radially inward proximate to a lower end of the housing. The device also includes a lower piston positioned in the bore. The lower piston is configured to move axially within the bore in response to a pressure differential across the lower piston. The lower piston is prevented from passing out through the lower end of the housing by the stop. The lower piston has a lower piston hole formed therethrough. The device also includes an upper piston positioned in the bore. The upper piston is configured to move axially within the bore in response to a pressure differential across the upper piston. The upper piston has an upper piston hole formed therethrough. The device is configured to receive a fluid in the bore, between the upper and lower pistons.

The invention relates to a method for determining the origin of a mixture of constituents by spectral analysis. The invention especially relates to a method for determining the concentration and origin of raw gases and/or crude oils in a mixing zone following mixing by the transport of said raw gases and/or crude oils that come from at least two different sources of extraction, said method comprising a specific spectral analysis.

A method of analyzing crude oil that may include the step of contacting the crude oil with an ionic liquid to form a treated sample. The method may further include determining presence of RAD in the treated sample.

Systems, devices, and techniques for determining downhole fluid contamination are disclosed. In one or more embodiments, phase-related properties are measured for a reservoir fluid having a determined composition. An equation-of-state (EOS) is selected and/or tuned based, at least in part, on the measured phase-related properties and the tuned EOS is applied to estimate fluid property values for a reference fluid over specified ranges of at least two thermodynamic properties. Contaminant reference data are generated that correlate the estimated fluid property values for the reference fluid with respective contaminant levels. Within a wellbore, a fluid sample is analyzed to determining a fluid property values. A contaminant level is identified that corresponds within the contaminant reference data to the determined fluid property value of the fluid sample.

The invention relates to a sensor assembly to detect and quantify organic and/or inorganic mercury compounds, including elemental mercury that may be present in gases or liquids, such as natural gas, air, condensates, crude oil, refined petroleum gas or liquids, and water including connate water, condensed water and water containing hydrate inhibitor(s). The sensor assembly includes a housing having a flow channel defined by an inlet, a sensor array, and an outlet. The sensor array is based on the differential sorption properties measured using a surface acoustic wave (SAW) sensor array, a chemiresistor array, or a combination of the two.

A vessel sensor for measuring real-time data of a multiphase fluid, the vessel sensor having a housing; an inner electrode, wherein the inner electrode is positioned within the housing; and a vessel cavity located between the housing and the inner electrode.

A method of screening a hydrocarbon stream for potential toxicological hazards. The method involves providing a hydrocarbon stream; conducting 2-dimensional gas chromatography (2D-GC) analysis to quantify saturates and aromatic distribution in the hydrocarbon stream; identifying 2-8 ring aromatic distribution and weight percentage of 2-8 ring aromatic molecules in the hydrocarbon stream from the 2D-GC analysis; relating the weight percentage of 2-8 ring aromatic molecules in the hydrocarbon stream from the 2D-GC analysis to a mutagenicity index (MI), in which the MI is determined in accordance with ASTM Standard Method E 1687; and assessing a potential toxicological hazard of the hydrocarbon stream based on the weight percentage of 2-8 ring aromatic molecules in the hydrocarbon stream from the 2D-GC analysis and a MI threshold value. The 2-8 ring aromatic distribution preferably includes 3-6 ring aromatics, more preferably 3.5-5.5 ring aromatics. The 2-8 ring aromatic distribution includes mono alkylated and multi alkylated aromatic molecules.