Abstract: An instrument for measuring gravitational acceleration, the instrument including: a plurality of accelerometers disposed about a three-dimensional structure, the plurality of accelerometers providing output used for measuring the gravitational acceleration; wherein each accelerometer in the plurality is implemented by at least one of a micro-electromechanical system (MEMS) and a nano-electromechanical system (NEMS).

Abstract: The present invention provides a method and apparatus for performing elemental analysis of a formation fluid downhole. The present invention provides elemental analysis of a formation fluid downhole using breakdown spectroscopy. In one aspect of the invention, a method and apparatus are provided for performing laser induced breakdown on a formation fluid sample is provided. In another aspect of the invention a method and apparatus are provided for performing spark induced breakdown spectroscopy. Plasma is induced in a fluid under test downhole. Emissions from the plasma are analyzed to determine the elemental composition of the fluid under test. Emissions include but are not limited to light in the ultraviolet, visible, and near infrared regions of the spectrum. A spectrometer is provided for elemental analysis of a fluid downhole. Elemental analysis yields information about the fluid and the formation from which the fluid originated.

Abstract: An instrument for measuring gravitational acceleration from within a borehole, the instrument including: a light source having a semiconductor that comprises a bandgap greater than about two electron volts (eV); and a gravimeter for receiving light from the light source and providing output light with a characteristic related to the gravitational acceleration, the gravimeter implemented at least one of a nano electromechanical system (NEMS) and a micro electromechanical system (MEMS); wherein the light source and the gravimeter are disposed in a housing adapted for insertion into the borehole.

Abstract: A method of determining properties of a formation fluid based on measurements of fluid sound speed, a measurement of fluid density, or both. The properties include compressibility, thermal conductivity, and gas oil ratio. The compressibility of a fluid is equal to the reciprocal of the product of the sound speed squared and fluid density. The density and the sound speed can be measured acoustically. The method further includes a manner of processing data including applying the Savitzky-Golay method and utilizing a variable thresholding technique.

Abstract: An illustrative embodiment is disclosed, including but not limited to an apparatus for estimating a property of a fluid downhole, including but not limited to a piezoelectric flexural mechanical resonator disposed in the fluid downhole; an electrode embedded in the piezoelectric flexural mechanical resonator; and a substantially transparent conductive coating covering the piezoelectric flexural mechanical resonator. A method is disclosed for estimating a property of a fluid downhole, the method including but not limited to embedding an electrode in a piezoelectric flexural mechanical resonator; coating the piezoelectric flexural mechanical resonator with a substantially transparent conductive coating; and disposing a piezoelectric flexural mechanical resonator disposed in the fluid downhole.

Abstract: A method and apparatus are provided that assess reservoir compartmentalization by determining whether there are compositional differences such as whether the isotopic ratios of carbon (13C/12C) or of oxygen (17O/18O) are the same or different in various parts of the reservoir. A quartz enhanced photoacoustic spectrometer is provided for analysis of reservoir samples taken in various parts of the reservoir for comparison of geochemical composition to estimate reservoir compartmentalization.

Abstract: An instrument for use in a borehole, the instrument including a pressure tuned light source disposed in a housing adapted for insertion into the borehole.

Abstract: A formation fluid sample is exposed to a rigidly-supported semi-permeable membrane such as silicone rubber to permit diffusion of gases and vapors from the formation fluid into a vacuum chamber, while at the same time, blocking the passage of any liquids. The membrane-transmitted gas is analyzed in the vacuum chamber by a sorbent-coated resonator. The sorbent absorbs gas and changes the resonant frequency of the resonator to indicate the presence of a gas. An ion pump or sorbent is associated with the evacuated chamber to maintain the vacuum. The ion pump or sorbent removes gases and vapors from the chamber that diffuse into the chamber from the reservoir sample that is on the opposite side of the semi-permeable membrane.

Abstract: Techniques for evaluating physical aspects of a formation fluid from within a wellbore include changing pressure on a sample of the formation fluid and transmitting at least one acoustic pulse through the fluid sample and analyzing acoustic information collected. Apparatus and methods for the evaluating involve using at least one acoustic transducer. Analyzing typically involves use of formulae that relate the fluid's equation of state and other properties to a change in the sound speed in the fluid as a function of pressure.

Abstract: The present invention provides an apparatus and method for high resolution spectroscopy using a narrow light beam source such as a superluminescent diode (SLD) and a tunable optical filter (TOF) for analyzing a formation fluid sample downhole and at the surface to determine formation fluid parameters. The SLD and TOF have a matching etendue. The analysis comprises determination of gas oil ratio, API gravity and various other fluid parameters which can be estimated after developing correlations to a training set of samples using a neural network or a chemometric equation.

Abstract: A method, system and an apparatus for estimating a property of a fluid in a wellbore are disclosed. In one aspect, the fluid may be exposed to light and light reflected by or passed through the fluid may be separated into a plurality of channels by a plurality of photonic crystals, each providing light corresponding to particular center wavelength. In another aspect, the light may be passed through a plurality of photonic crystals to provide light centered about one or more wavelengths. The fluid then may be exposed to the light output from the photonic crystals. Light detected from the fluid corresponding to each center wavelength is processed to estimate the parameter of interest.

Abstract: A method is disclosed for changing an optical path length through a fluid downhole, comprising interspersing an optically transmissive member into a first optical path through the fluid, thereby creating a second shorter optical path through the fluid. In another embodiment, the method further comprises measuring an intensity of light, I1 transmitted through the first optical path; measuring an intensity of light, I2 transmitted through the second optical path; and estimating an optical property for the second optical path from the ratio, I1/I2. A system is disclosed for changing an optical path length through a fluid downhole, comprising a fluid passage between two optically transmissive windows for the fluid downhole, the fluid passage having a first optical path through the fluid; and an optically transmissive member for insertion into the first optical path, thereby creating a second shorter optical path through the fluid.

Abstract: In one embodiment an apparatus is disclosed that includes a tool in a wellbore. A probe is extendable from the tool to contact a wall of a formation surrounding the wellbore. A tube substantially surrounds the probe wherein the tube is extendable into the formation surrounding the wellbore. In another embodiment a method for reducing contamination of a sample of a formation fluid is disclosed that includes extending a probe to contact a wall of a formation. A barrier tube that substantially surrounds the probe is extended into the formation thereby restricting a flow of a contaminated reservoir fluid that would otherwise come from near-wellbore regions above and below the probe from going toward the probe.

Abstract: A method for measuring true vertical depth in a borehole, the method including: measuring gravitational acceleration in the borehole; and determining the true vertical depth from the measurement.

Abstract: Apparatus and method are disclosed for detecting gas in return fluids. A semi-permeable interface is disposed on a tool sub, the semi-permeable interface being in communication with a fluid cell and with a return fluid in an annular region defined by an outside the tool sub and a borehole wall. A sensor responsive to a gas carried by the return fluid is disposed in the fluid cell to sense the gas that enters the fluid cell from the return fluid via the semi-permeable interface.

Abstract: In one aspect, an apparatus is disclosed that includes an anisotropic nanocomposite element in thermal communication with a heat-generating element for conducting heat away from the heat-generating element along a selected direction. In another aspect, a method of conveying heat away from a heat-generating element is disclosed that includes transferring heat from the heat-generating element to an anisotropic nanocomposite element that is configured to conduct heat along a selected direction, and transferring heat received by the anisotropic nanocomposite element to a heat-absorbing element.

Abstract: Embodiments of conductive polymers and instruments using the conductive polymers in geophysical exploration are provided. Methods for fabrication are included.

Abstract: In a particular embodiment, a method and system are disclosed for measuring ion concentrations for a fluid and determining a degree of sample cleanup during sampling of a fluid downhole. The method includes but is not limited to deploying an ion selective sensor downhole, exposing the fluid to the ion selective sensor downhole, measuring ion concentrations of the fluid over time during sampling and estimating a degree of sample clean up from the ion concentration measurements. The system includes but is not limited to a tool deployed in a wellbore, an ion selective sensor in the tool, a processor in communication with the ion selective sensor and a memory for storing an output from the ion selective sensor.

Abstract: An apparatus is disclosed for controlling heat flow in a downhole tool using a thermal rectifier material. The thermal rectifier material is positioned between a heat source and a heat sink for reducing flow of heat returning from the heat sink to the heat source. That is, the thermal rectifier conceptually operates as a “thermal check valve” so that heat, which has flowed (or been pumped) out of a region, has difficulty returning to that region. Another embodiment of an apparatus is disclosed for controlling heat flow in a downhole tool, which includes a thermal rectifier material surrounding a liquid supply, wherein the thermal rectifier material allows more heat to flow through the thermal rectifier in a first direction away from the liquid supply than in a direction through the thermal rectifier material toward from the liquid supply. A method for controlling heat flow in a downhole tool using a thermal rectifier material is also disclosed.

Abstract: A method and apparatus is described for estimating terminal purity or terminal contamination for a fluid during the withdrawal of the fluid from a subsurface formation. The apparatus and method provide for measuring refractive index of the fluid over a time period, fitting a curve through the refractive index measurements or data values derived therefrom and estimating a terminal refractive index or terminal value for the data values from the fitted to curve to estimate the terminal contamination or purity for the fluid.