Abstract: Methods and related systems are described for a sealed housing for downhole transducers. The housing system includes a housing body and a transducer positioned within the housing body, and one or more flexible members sealably mounted on the housing body. The flexible members each have one or more undulations which facilitate movement of the flexible member in directions primarily perpendicular to the surface of the flexible member. The dimensions of the one or more undulations are designed so as to optimize the ability of the movements of the member thereby accommodating volume changes in the sealed housing. A substantial amount of compensating material can also be positioned within the housing body. The compensating material has a coefficient of thermal expansion substantially less than that of the housing material.

Abstract: Methods and apparatus to determine a concentration of nitrogen in a downhole fluid are described. An example apparatus to determine a concentration of nitrogen in a downhole fluid includes a fluid measurement unit to measure a first fluid composition and a density of at least a hydrocarbon and carbon dioxide in a sample of the downhole fluid. Additionally, the example apparatus includes one or more sensors to measure at least a pressure and a temperature of the sample. Further, the example apparatus includes a processing unit to determine a first theoretical density based on at least the first fluid composition, the temperature, and the pressure the sample. Further still, the example apparatus includes an analyzer to determine a first difference between the density of at least the hydrocarbon and the carbon dioxide in the sample and the first theoretical density. The first difference is associated with a concentration of nitrogen in the sample.

Abstract: Methods and systems for determining coil eccentricity of seismic sensors configured or designed for use in seismic signal detection. A direct electrical current is applied to a moving coil of a seismic sensor such that the moving coil is dislocated from a neutral position relative to the magnetic field in the seismic sensor. A predetermined indicator is measured and eccentricity of the coil (?) relative to the center of the magnetic filed is determined using the predetermined indicator.

Abstract: Methods and apparatus for determining a presence of a non-conductive coating on electrodes in fluid resistivity measurement devices are described. An example method of determining a presence of a non-conductive coating on electrodes of a fluid resistivity measurement device involves obtaining a first electrical potential value associated with a substantially uncoated condition of first and second electrodes of a fluid resistivity measurement device. The example method also involves measuring a second electrical potential value at a location between the first and second electrodes, comparing the first and second electrical potential values, and determining the presence of a non-conductive coating on at least one of the first and second electrodes based on the comparison.

Abstract: The present invention contemplates implementation of transitory downhole video imaging and/or spectral imaging for the characterization of formation fluid samples in situ, as well as during flow through production tubing, including subsea flow lines, for permanent and/or long term installations. The present invention contemplates various methods and apparatus that facilitate one-time or ongoing downhole fluid characterization by video analysis in real time. The methods and systems may be particularly well suited to permanent and periodic intervention-based operations.

Abstract: Single fiber optical telemetry systems and methods are disclosed. The methods and systems facilitate input and output via a single fiber optic interface. The optical telemetry systems and methods also facilitate faster data transmission rates between surface and downhole equipment in oilfield applications.

Abstract: A method and system for fluid characterization in an underground formation surrounding a borehole are provided. Acoustic signals are transmitted and received in the borehole. The received acoustic signals are processed to obtain at least one attribute of formation mobility. Formation fluid is characterized based on a change of the at least one attribute. A decision is made based on the characterization output.

Abstract: A method and system for monitoring any incursion of particulate matter from a gas hydrate formation into a well casing used for the production of the gas hydrate and determining the degree of incursion of particulate material within the distal end of the well casing.

Abstract: Methods and apparatus for removing deposits on components in a downhole tool are described. An example apparatus to remove a deposit on an inner surface of a flowline in a downhole tool includes a movable scraper disposed in a flowline of a downhole tool. The movable scraper is configured to selectively obstruct the flowline so that a fluid flowing in the flowline moves the movable scraper in the flowline. Additionally, the movable scraper has an outer surface configured to engage an inner surface of the flowline so that movement of the outer surface along the inner surface removes a deposit on at least a portion of the inner surface.

Abstract: A method and a tool that implements a method which includes measuring the viscosity and flow rates of formation fluids and obtaining the ratio of relative permeabilities of the formation fluids and wettability of the formation using the same.

Abstract: A method and apparatus for deploying seismic detectors and monitoring seismic activity associated with a production well from a down hole location within a well.

Abstract: A method and system for azimuth measurements using one or more gyro sensors is disclosed. The method includes acquiring a first data from each of the gyro sensors with an input axis aligned to a first angular orientation and acquiring a second data from each of the gyro sensors with the input axis flipped to a second angular orientation opposite to the first angular orientation. An earth rate component at the first angular orientations is determined based on a difference between the first data and the second data to cancel out bias of each of the gyro sensors. The method may include acquiring a third data of the gyro sensor with the input axis aligned to the same angular orientation as the first angular orientation. An average of the first data and the third data may be used instead of the first data for determining the earth rate component.

Abstract: A downhole tool, configured to be suspended in a borehole traversing an earth formation, includes a downhole data acquisition system placed in the tool body and electrically connected to an electric power generator at the formation surface. The downhole data acquisition system includes a sensor for detecting local conditions in the borehole, and a transducer for transducing the voltage of an input signal from high to low or low to high. The transducer having a gallium nitride or silicon carbide based discrete semiconductor device.

Abstract: A method of downhole characterization of formation fluids is provided. The method includes: estimating a rough value of the bubble point pressure of the formation fluids; depressurizing the formation fluids at a first speed to a certain pressure which is a predetermined value higher than the estimated rough value while the formation fluids are isolated in a portion of the flowline; and depressurizing the isolated fluids at a second speed which is slower than the first speed in order to measure a precise value of the bubble point pressure.

Abstract: Methods and apparatus for navigating a subterranean tool comprising a body member and a head member steerably associated with the body member. A determining unit is configured to determine a transversal target position of a nose of the head member relative to the body member and a steering unit is configured to steer the head member relative to the body member so that the nose of the head member is located at the transversal target position.