Abstract: Methods and apparatus for downhole analysis of formation fluids by isolating the fluids from the formation and/or borehole in a pressure and volume control unit that is integrated with a flowline of a fluid analysis module and determining fluid characteristics of the isolated fluids. Parameters of interest may be derived for formation fluids in a static state and undesirable formation fluids may be drained and replaced with formation fluids that are suitable for downhole characterization or surface sample extraction. Isolated formation fluids may be circulated in a loop of the flowline for phase behavior characterization. Real-time analysis of the fluids may be performed at or near downhole conditions.

Abstract: Some principles described herein contemplate implementation of downhole imaging for the characterization of formation fluid samples in situ, as well as during flow through production tubing, including subsea flow lines, for short term investigation, permanent, and/or long term installations. Various methods and apparatus described herein may facilitate downhole testing. For example, some embodiments facilitate multi-dimensional fluorescence spectrum measurement testing downhole.

Abstract: Some principles described herein comtemplate implementation of downhole imaging for the characterization of formation fluid samples in situ, as well as during flow through production tubing, including subsea flow lines, for short term investigation, permanent, and/or long term installations. Various methods and apparatus described herein may facilitate downhole testing. For example, some embodiments facilitate multi-dimensional fluorescence spectrum measurement testing downhole and correlating the fluorescence with other oil properties.

Abstract: The present invention provides packaging for MEMS devices and other sensors for downhole application. The MEMS devices and/or other sensors may aid in characterizing formation fluids in situ. The packaging facilitates high temperature, high pressure use, which is often encountered in downhole environments.

Abstract: A downhole fluid analysis system comprises an input light signal that is directed through a fluid sample housed in a sample cell. The input light signal may originate from a plurality of light sources. A light signal output from the sample cell is then routed to two or more spectrometers for measurement of the represented wavelengths in the output light signal. The output of the spectrometers is then compared to known values for hydrocarbons typically encountered downhole. This provides insight into the composition of the sample fluid. Additionally, the input light can be routed directly to the two or more spectrometers to be used in calibration of the system in the high temperature and noise environment downhole.

Abstract: Spectral analysis system for downhole applications is provided utilizing an inorganic replica-type grating that is configured to operate as a diffractive element that provides broad spectral coverage in high temperature downhole environments.

Abstract: A downhole fluid analysis system comprises an input light signal that is directed through a fluid sample housed in a sample cell. The input light signal may originate from a plurality of light sources. A light signal output from the sample cell is then routed to two or more spectrometers for measurement of the represented wavelengths in the output light signal. The output of the spectrometers is then compared to known values for hydrocarbons typically encountered downhole. This provides insight into the composition of the sample fluid. Additionally, the input light can be routed directly to the two or more spectrometers to be used in calibration of the system in the high temperature and noise environment downhole.

Abstract: An apparatus for analyzing subterranean formation fluids includes a downhole tool, a fluid analysis module disposed in the downhole tool, a formation fluid flow path through the fluid analysis module, first and second cavities disposed in the fluid analysis module, and first and second windows disposed in first and second cavities of the fluid analysis module, respectively. The first and second windows each comprise a polished external sealing surface enabling high pressure fluid isolation.

Abstract: An apparatus for performing real-time analysis of a subterranean formation fluid includes a light source configured to transmit at least a sample signal through a sample of the subterranean formation fluid and a reference signal, at least one photodetector configured to continuously detect the sample and reference signals, and an electronics assembly configured to compensate for drift in the detected sample signal in real-time based on the value of the detected reference signal.

Abstract: The present invention provides packaging for MEMS devices and other sensors for downhole application. The MEMS devices and/or other sensors may aid in characterizing formation fluids in situ. The packaging facilitates high temperature, high pressure use, which is often encountered in downhole environments.

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: Methods and apparatus for downhole analysis of formation fluids by isolating the fluids from the formation and/or borehole in a pressure and volume control unit that is integrated with a flowline of a fluid analysis module and determining fluid characteristics of the isolated fluids. Parameters of interest may be derived for formation fluids in a static state and undesirable formation fluids may be drained and replaced with formation fluids that are suitable for downhole characterization or surface sample extraction. Isolated formation fluids may be circulated in a loop of the flowline for phase behavior characterization. Real-time analysis of the fluids may be performed at or near downhole conditions.

Abstract: Methods of analyzing formation fluids in an oilfield environment are near-infrared absorption spectroscopy. Indications of near-infrared absorptions are analyzed to determine the concentration of compounds in a formation fluid sample.

Abstract: A method and apparatus detects dew precipitation and determines dew precipitation onset pressure in a sample of formation fluid located downhole in an oilfield reservoir. In a preferred embodiment, the method includes (a) isolating a sample of formation fluid downhole; (b) illuminating the sample downhole with fluorescence excitation light; (c) measuring at least one characteristic of fluorescence short from the sample; (d) reducing pressure on the sample; (e) repeating steps (b) to (d); (f) detecting dew precipitation when a change is detected in a parameter that is a function of the at least one characteristic of fluorescence emission; and (g) setting dew precipitation onset pressure equal to pressure on the sample when the change in the parameter is detected. The parameter preferably is a function of fluorescence intensity and fluorescence red shift, and the change is an increase in fluorescence intensity and detection of fluorescence red shift.

Abstract: A method for determining properties of a formation fluid including obtaining data related to an optical density at a methane peak and an optical density at an oil peak for a fluid sample at a plurality of times, calculating an apparent gas-oil-ratio of the sample fluid from the optical density of the fluid sample at the methane peak to the optical density of the fluid sample at the oil peak at each of the plurality of times based on the data, selecting a power function of a sampling parameter for a buildup of the apparent gas-oil-ratio, calculating an exponential constant of the power function based on the data, and determining at least one selected from the group consisting of a contamination free gas-oil-ratio and a percent contamination.

Abstract: A method for determining properties of a formation fluid including obtaining data related to an optical density at a methane peak and an optical density at an oil peak for a fluid sample at a plurality of times, calculating an apparent gasoilratio of the sample fluid from the optical density of the fluid sample at the methane peak to the optical density of the fluid sample at the oil peak at each of the plurality of times based on the data, selecting a power function of a sampling parameter for a buildup of the apparent gasoilratio, calculating an exponential constant of the power function based on the data, and determining at least one selected from the group consisting of a contamination free gasoilratio and a percent contamination.

Abstract: A method of determining GOR comprising subjecting a fluid to spectroscopic analysis at a first wavelength sensitive to gas and a second wavelength sensitive to oil, determining a response matrix for the contribution of gas at the first and second wavelengths and the contribution of oil at the first and second wavelengths, determining a signal response vector and the two wavelengths, calculating a mass fraction vector from the response matrix and the signal response vector and using the mass fraction vector to determine GOR.

Abstract: Methods of analyzing formation fluids in an oilfield environment are near-infrared absorption spectroscopy. Indications of near-infrared absorptions are analyzed to determine the concentration of compounds in a formation fluid sample.

Abstract: A method and apparatus detects dew precipitation and determines dew precipitation onset pressure in a sample of formation fluid located downhole in an oilfield reservoir. In a preferred embodiment, the method includes (a) isolating a sample of formation fluid downhole; (b) illuminating the sample downhole with fluorescence excitation light; (c) measuring at least one characteristic of fluorescence short from the sample; (d) reducing pressure on the sample; (e) repeating steps (b) to (d); (f) detecting dew precipitation when a change is detected in a parameter that is a function of the at least one characteristic of fluorescence emission; and (g) setting dew precipitation onset pressure equal to pressure on the sample when the change in the parameter is detected. The parameter preferably is a function of fluorescence intensity and fluorescence red shift, and the change is an increase in fluorescence intensity and detection of fluorescence red shift.

Abstract: A method of determining GOR comprising subjecting a fluid to spectroscopic analysis at a first wavelength sensitive to gas and a second wavelength sensitive to oil, determining a response matrix for the contribution of gas at the first and second wavelengths and the contribution of oil at the first and second wavelengths, determining a signal response vector and the two wavelengths, calculating a mass fraction vector from the response matrix and the signal response vector and using the mass fraction vector to determine GOR.