Devices, systems, and methods for determining gas characteristics to monitor transformer operation include extracting gas from transformer fluid for analysis.

Devices, systems, and methods for determining gas characteristics to monitor transformer operation include extracting gas from transformer fluid for analysis.

The invention relates to a system and to a method for separating into at least one of liquid and gas phase compounds contained in a sample. The system comprises: an oven (D1) for heating in an inert atmosphere according to a sequence of temperatures, a first experimental setup (M1) connected to oven (D1) when it is in operation, comprising circulating the effluent resulting from heating in an inert atmosphere towards collection of (U) this effluent, a second experimental setup (M2) connected to first experimental setup (M1) when the oven is no longer in operation, comprising vacuum circulation (PI, P.G., TP) of the effluent collected by the first setup towards (T1, T2) which separate the collected effluent into at least one of liquid and gas phases.

A method and system for estimating clean fluid composition and properties. A method may comprise disposing a downhole fluid sampling tool into a wellbore, wherein the downhole fluid sampling tool comprises optical instrumentation, obtaining a fluid sample with the downhole fluid sampling tool, wherein the fluid sample comprises a reservoir fluid contaminated with a well fluid, identifying input parameters from at least one sensor response on the optical instrumentation, and predicting a clean fluid sample of the reservoir fluid using an asymptote of a dimensional reduction analysis and equation of state. A system may comprise a downhole fluid sampling tool and a processing unit. The downhole fluid sampling tool may further comprise an optical instrumentation operable to obtain fluid samples of a reservoir fluid contaminated with a well fluid while the downhole fluid sampling tool is disposed in a wellbore.

A method of analyzing dissolved gas in an oil-filled transformer includes determining a centroid of a polygon that represents a plurality of dissolved gas concentrations. A fault region in which the centroid of the polygon is located is determined, where the plurality of fault regions are defined in a composite fault region map that is a composite of a Duval Pentagons 1 and 2. The method classifies a fault experienced by the transformer based on the determined fault region within the composite fault region map. The classification is done by a machine learning classification technique. Further embodiments classify faults based on dissolved gas levels without determining a centroid of a polygon representing the dissolved gas levels. Related systems are also disclosed.

Devices, systems, and methods for determining gas characteristics to monitor transformer operation include extracting gas from transformer fluid for analysis.

According to an example aspect of the present invention, there is provided analyzing fault gas concentrations in a liquid. Concentration of at least one dissolved fault gas in the liquid is measured at least at two temperatures. Disturbing gas contribution is determined in at least one temperature on the basis of the fault gas concentration measurements. Fault gas concentrations are analyzed by compensating fault gas concentrations on the basis of the determined disturbing gas contribution.

Provided in the present invention a method for evaluating the mixing effect of a CO.sub.2 oil-displacing and mixing agent, characterized in measuring the volume expansion of a CO.sub.2-oil interface when pressure is gradually increased, drawing a mixed-phase percentage-pressure curve (-P curve), and evaluating the mixing effect of the CO.sub.2 oil-displacing and mixing agent by means of comparing the characteristics of the -P curve. Further provided in the present invention is a method for initially screening a CO.sub.2 oil-displacing and mixing agent.

The present invention is directed to a method of estimating an overheating temperature of an oil-immersed electric appliance in which ester oil is used as insulating oil. The overheating temperature is estimated based on a first concentration ratio representing a concentration ratio between two types of gas components contained in the ester oil and a second concentration ratio representing a concentration ratio between other two types of gas components contained in the ester oil. The first concentration ratio and the second concentration ratio are selected from a concentration ratio between acetylene and ethane, a concentration ratio between acetylene and hydrogen, a concentration ratio between acetylene and methane, and a concentration ratio between acetylene and ethylene.

A system and a method are provided for calculating the cetane number, pour point, cloud point, aniline point, aromaticity, and/or octane number of a gas oil or naphtha fraction of a crude oil from the density and Fourier transform infrared spectroscopy (FTIR) of a sample of the crude oil, without first distilling the crude oil into the gas oil or naphtha fraction.