Abstract: The diffusion coefficients and relaxation times of mixtures of alkanes follow simple scaling laws based on the chain length of the constituents and the mean chain length of the mixture. These scaling laws are used to determine chain sizes in a mixture from the distribution of the diffusion coefficients. These scaling laws can be used to determine the mean chain lengths (or chain lengths) of a sample (alkanes or mixtures of alkanes) and therefore the constituents of the sample.

Abstract: It is shown that a pressure pulse originating in a well is correlated to a pulse observed at a distant well with a characteristic time. The correlation time is directly related to the diffusion time scale arising out of the pressure diffusion equation. The relationship is affected by the source-observer or observer-observer distance but the correction is small for large distances. In practice, further corrections have to be included for finite width pulses. For these pulses, a practical scheme for continuous permeability monitoring is presented.

Abstract: This relates to methods and apparatus for analyzing samples by fluorescence spectroscopy. In one embodiment, the methods and apparatus use a fluorescence detection unit (FDU) of a composition fluid analyzer (CFA™) module to detect variations in fluid properties (gradients) within an oil bearing column. Some embodiments enable efficient downhole fluid analysis in heavy oils where water/oil emulsions are present (water in dispersed phase and oil in the continuous phase). The principles described herein may also be applied when there are fine particles in the oil such as from unconsolidated sands.

Abstract: The present invention provides methods and apparatus for separating and/or analyzing fluids of interest. According to principles of the present invention, fluid analysis is accomplished with microfluidic devices and may be reported in real-time or near real-time in a subterranean environment. In addition or alternative to oilfield applications, the principles of the present invention contemplate separation in a laboratory or other environment for biological sample separation and analytical chemistry applications. The present invention is capable of separating liquid-liquid mixtures or emulsions in a microfluidic device without fouling.

Abstract: A method and apparatus for improving spectral resolution of an NMR measurement in the presence of an inhomogeneous magnetic field. According to one embodiment, a method producing a high resolution nuclear magnetic resonance (NMR) spectrum for a sample in an inhomogeneous magnetic field may comprise generating a first magnetic pulse and a second magnetic pulse, the first and second magnetic pulses being separated in time by a first time period, during the first time period, generating a gradient pulse, repeating the steps of generating the first and second magnetic pulses and generating the gradient pulse N times for different values of a field strength of the gradient pulse, wherein N is an integer greater than one, after each second magnetic pulse, acquiring a signal from the sample, and producing a reconstructed high resolution NMR spectrum from the acquired signals.

Abstract: A betatron structure having a donut-shaped vacuum chamber, wherein the vacuum chamber is made up of two or more pieces bonded together; an injector positioned within the vacuum chamber; and two or more magnets positioned to the outside of the vacuum chamber. A method of manufacturing a betatron structure, including: (a) fabricating two or more pieces; (b) positioning an injector on one of the two or more pieces; and (c) bonding the two or more pieces such that when bonded, the substrates form a hollow donut-shaped chamber.

Abstract: A heat switch for remote self-contained gas chromatography is disclosed. The device mechanically separates a hot or cold reservoir from the chromatography column when heating or cooling is not needed. The column needs a cooling system to obtain initial temperatures below ambient. At other times the column needs to be heated to relatively high temperatures, during which time the cooling system is preferably detached. The heat switch allows for rapid temperature changes while minimizing the peak cooling power requirement.

Abstract: A self-contained micro-scale gas chromatography system that includes a plurality of gas chromatography components arranged on a micro-fluidic platform with nearly zero dead volume “tubeless” fluidic connections for the gas chromatography components. The micro-fluidic platform includes a plurality of flow channels that provide fluid flow paths for a sample, carrier gas and waste gas through and among the micro-fluidic platform and the plurality of gas chromatography components. The gas chromatography components may include a micro-scale gas chromatography column that is implemented as a MEMS device and includes embedded heating and cooling elements. The system may also include an on-board supply of carrier gas and on-board waste management, as well as a thermal management scheme making the system suitable for use in oil and gas wells and also other remote environments.

Abstract: The operation, analysis and interpretation of a chromatographic system can be significantly enhanced by coupling therewith one or more fluid property measurements that provides an initial indication of the fluid type, the presence of any contamination, an estimate of the hydrocarbon composition (C1, C2-C5 and C6+), gas/oil ratio, color and/or fluorescence measurements. Other measurements that can be used in the initial stage can include density, viscosity, phase transition determinations. These measurements may be used to enhance, in real-time, the GC sampling protocol, the analysis protocol and also improve the robustness of the interpretation of the chromatogram.

Abstract: A betatron includes a betatron magnet with a first guide magnet having a first pole face and a second guide magnet having a second pole face. Both the first and the second guide magnet have a centrally disposed aperture and the first pole face is separated from the second pole face by a guide magnet gap. A core is disposed within the centrally disposed apertures in an abutting relationship with both guide magnets. The core has at least one core gap. A drive coil is wound around both guide magnet pole faces. An orbit control coil has a contraction coil portion wound around the core gap and a bias control portion wound around the guide magnet pole faces. The contraction coil portion and the bias control portion are connected but in opposite polarity. Magnet fluxes in the core and guide magnets return through peripheral portions of the betatron magnet.