The present invention concerns a system (1) for extracting gas or gas mixtures from a liquid for performing dissolved gas or gas mixture analysis, the system (1) comprising a container (2) for storing a liquid and/or a gas or gas mixture, a liquid pump (3) which is connected to the container (2), a means for feeding the system (1) with a liquid and emptying the system (1) of the liquid, a gas analyzer which is connected to the container (2), and a piping (14) which is connected to the container (2), and wherein the piping (14), the liquid pump (3) and the container (2) are configured to circulate the liquid. The invention also concerns a method for extracting gas or gas mixtures from a liquid for performing dissolved gas or gas mixture analysis.

A method of detecting at least one of an analyte or a condition of a fluid within a subterranean formation comprises operably coupling a radiation source to at least one optical fiber coupled to a sensor comprising optically sensitive materials including at least one of chromophores, fluorophores, metal nanoparticles, or metal oxide nanoparticles dispersed within an optically transparent permeable matrix material. The sensor is contacted within a wellbore with a fluid and the fluid is passed through at least a portion of the sensor. Electromagnetic radiation is transmitted from the radiation source through at least one optical fiber to the sensor and at least one of an absorbance spectrum, an emission spectrum, a maximum absorption intensity, or a maximum emission intensity of electromagnetic radiation passing through the sensor after contacting at least some of the optically sensitive materials with the fluid is measured. Additional methods of determining a concentration of hydrogen sulfide in a fluid within a subterranean formation and related downhole optical sensor assemblies are disclosed.

A method of testing a pressurized liquid fluid for dissolved gasses includes evacuating both a first tank and a second tank. A test volume of a pressurized liquid fluid is introduced into the first tank. An initial absolute pressure in the second tank is sensed, and then fluid communication between the first tank and the second tank is opened to allow the pressurized fluid to flow from the first tank into the second tank, thereby de-pressurizing the fluid. The de-pressurized fluid in the second tank is maintained for a pre-defined out-gassing period, to allow any gasses in the de-pressurized fluid to separate from the de-pressurized fluid. A final absolute pressure in the second tank is sensed. A difference between the final absolute pressure and the initial absolute pressure is correlated to a volume of gasses released from the de-pressurized fluid.

The method for diagnosing the oil-filled electrical apparatus in the present invention is a method for diagnosing whether or not discharge has occurred inside the oil-filled electrical apparatus. The diagnosing method includes: an in-oil gases analyzing step of analyzing hydrogen gas and a gas selected from the group consisting of methane, ethane, ethylene, acetylene, hydrocarbon having a carbon number of 3 or 4, carbon monoxide, carbon dioxide, oxygen, and nitrogen, contained in an insulating oil used inside the oil-filled electrical apparatus; a step of analyzing a causative substance serving as a cause of generation of hydrogen in the insulating oil irrespective of whether or not the discharge has occurred; and a step of diagnosing whether or not the discharge has occurred based on an analysis result of the in-oil gases analyzing step and an analysis result of the step of analyzing the causative substance.

Systems and methods for selectively extracting hydrogen gas dissolved in oil are provided. In one embodiment, a system includes a selectively permeable membrane provided at a point of contact between oil and a sensor chamber. The selectively permeable membrane has a hydrogen specificity and a thickness selected to minimize detection of further gasses dissolved in the oil by a hydrogen gas sensor cross-sensitive to the further gasses. The selectively permeable membrane can include polyimide. The further gasses include carbon monoxide, acetylene, and ethylene. The system can include a further membrane and a porous metal disc. The porous metal disc is bound to the selectively permeable membrane by using the further membrane as an adhesive layer and by applying pressure and temperature. The porous metal disc supports the selectively permeable membrane and the further membrane against pressure of the oil when exposed to a vacuum. The further membrane includes fluorohydrocarbons.

A method for estimating the gas-oil ratio (GOR) of a flowing oil well in real-time includes installing a first pressure downhole monitoring system in a flowing oil well, and installing a second pressure downhole monitoring system in a flowing oil well such that a pressure gradient can be calculated between a pressure measured by the first pressure downhole monitoring system and a pressure measured by the second pressure downhole monitoring system. Then the pressure is measured at the well-head of the oil well, and previous production test results of the oil well are reviewed in order to collect a liquid flow rate from the measured well-head pressure. Finally, known correlations between liquid flow rates and pressure gradients at constant GOR values are used to determine the GOR of the well.

Methods and apparatus for operating a downhole tool within a wellbore adjacent a subterranean formation to pump contaminated fluid from the formation into the downhole tool while measuring first and second fluid properties of the contaminated fluid. The contaminated fluid comprises native fluid from the formation and a contaminant. The downhole tool is in communication with surface equipment located at surface. The downhole tool and/or surface equipment is operated to estimate a formation volume factor of the contaminated fluid based on at least one of the first and second fluid properties of the contaminated fluid. A linear relationship is then estimated between the first fluid property and a function that relates the first fluid property to the second fluid property and the estimated formation volume factor of the contaminated fluid. A fluid property of the contaminant is then estimated based on the estimated linear relationship.

A method of testing a pressurized liquid fluid for dissolved gasses includes evacuating both a first tank and a second tank. A test volume of a pressurized liquid fluid is introduced into the first tank. An initial absolute pressure in the second tank is sensed, and then fluid communication between the first tank and the second tank is opened to allow the pressurized fluid to flow from the first tank into the second tank, thereby de-pressurizing the fluid. The de-pressurized fluid in the second tank is maintained for a pre-defined out-gassing period, to allow any gasses in the de-pressurized fluid to separate from the de-pressurized fluid. A final absolute pressure in the second tank is sensed. A difference between the final absolute pressure and the initial absolute pressure is correlated to a volume of gasses released from the de-pressurized fluid.

An apparatus for measuring dissolved gas includes a body having an internal space, a separator installation part provided in the body and having a separator allowing a dissolved gas to pass therethrough and blocking insulating oil installed therein, and a sensor installation part provided in the body and allowing a gas sensor measuring dissolved gas separated by the separator to be installed therein, wherein the separator installation part and the sensor installation part are configured in such a manner that the separator and the gas sensor are independently installed in the body or separated from the body. According to the apparatus for measuring dissolved gas, a gas sensor may be manufactured to be standardized, and excellent compatibility with respect to various types of gas sensors may be provided.

A system and a process for detecting early stage electrical components problems with an analysis system is disclosed. The system process includes determining an oil quality of the oil of an electrical component using the analysis system. The system the process further including determining dissolved gases in the oil of the electrical component using the analysis system, processing and analyzing the oil quality and the dissolved gases using the analysis system, and determining whether there are problems in the electrical component using the analysis system.