Abstract: A gas separation and detection tool for performing in situ analysis of borehole fluid is described. The tool comprises a sampling chamber for a downhole fluid. The sample chamber comprises a detector cell with an opening. The tool also comprises a gas separation module for taking a gas from the downhole fluid. The gas separation module comprises a membrane located in the opening, a support for holding the membrane, and a sealant applied between the housing and the membrane or support. Moreover, the tool comprises a gas detector for sensing the gas.

Abstract: A method (and corresponding apparatus) for downhole fluid analysis of petroleum formation fluids. The method includes capturing in a chamber of a downhole tool at least two immiscible formation fluids in a generally segregated state (the fluids including petroleum), activating a fluid mixing means to mix the fluids in the chamber to create an emulsion therefrom, and allowing the emulsified fluids to segregate while measuring light transmittance through the segregating fluids in order to calculate a transition time period based on the light transmittance through the fluids in the chamber. The transition time period is preferably bounded by the time required for the light transmittance values measured by the light detector to reach a baseline light transmittance. The transition time period characterizes the stability of an emulsion formed by the captured fluids. The methods and apparatus can also be used for other fluid testing applications beyond downhole formation fluid testing.

Abstract: Methods and apparatuses for analyzing a downhole fluid are disclosed. An example method may involve the steps of admitting the downhole fluid in a test volume, controllably inducing a pressure change in the test volume based on at least one prescribed rate, measuring pressures in the test volume at a plurality of times, using the pressures measured at the plurality of times to determine a time at which an actual rate of the pressure change in the test volume deviates from the at least one prescribed rate, and detecting an occurrence of phase transition of the downhole fluid based on the determined time.

Abstract: A system for determining the asphaltene content of crude oil includes a first optical flow cell, a first spectrometer operably associated with the first optical flow cell, and a mixer in fluid communication with the first optical flow cell. The system further includes a crude oil injection/metering device configured to receive the crude oil, the crude oil injection/metering device being in fluid communication with the first optical flow cell; a titrant injection/metering device in fluid communication with the mixer, the titrant injection/metering device configured to receive a titrant; and a filtration unit in fluid communication with the mixer. The system further includes a second optical flow cell in fluid communication with the filtration unit, and a second spectrometer operably associated with the second optical flow cell.

Abstract: A method and system for characterizing asphaltene gradients of a reservoir of interest and analyzing properties of the reservoir of interest based upon such asphaltene gradients. The analysis employs a correlation that relates insoluble asphaltene concentration to spectrophotometry measurement data measured at depth.

Abstract: Example methods and apparatus to determine phase-change pressures are disclosed. A disclosed example method includes capturing a fluid in a chamber, pressurizing the fluid at a plurality of pressures, measuring a plurality of transmittances of a signal through the fluid at respective ones of the plurality of pressures, computing a first magnitude of a first subset of the plurality of transmittances, computing a second magnitude of a second subset of the plurality of transmittances, comparing the first and second magnitudes to determine a phase-change pressure for the fluid.

Abstract: A method (and corresponding apparatus) for downhole fluid analysis of petroleum formation fluids. The method includes capturing in a chamber of a downhole tool at least two immiscible formation fluids in a generally segregated state (the fluids including petroleum), activating a fluid mixing means to mix the fluids in the chamber to create an emulsion therefrom, and allowing the emulsified fluids to segregate while measuring light transmittance through the segregating fluids in order to calculate a transition time period based on the light transmittance through the fluids in the chamber. The transition time period is preferably bounded by the time required for the light transmittance values measured by the light detector to reach a baseline light transmittance. The transition time period characterizes the stability of an emulsion formed by the captured fluids. The methods and apparatus can also be used for other fluid testing applications beyond downhole formation fluid testing.

Abstract: A system and method for determining at least one fluid characteristic of a downhole fluid sample using a downhole tool are provided. In one example, the method includes performing a calibration process that correlates optical and density sensor measurements of a fluid sample in a downhole tool at a plurality of pressures. The calibration process is performed while the fluid sample is not being agitated. At least one unknown value of a density calculation is determined based on the correlated optical sensor measurements and density sensor measurements. A second optical sensor measurement of the fluid sample is obtained while the fluid sample is being agitated. A density of the fluid sample is calculated based on the second optical sensor measurement and the at least one unknown value.

Abstract: A system and method for obtaining a clean fluid sample for analysis in a downhole tool are provided. In one example, the method includes directing fluid from a main flowline of the downhole tool to a secondary flowline of the downhole tool. While the fluid is being directed into the secondary flowline, sensor responses corresponding to the fluid in the secondary flowline are monitored to determine when the sensor responses stabilize. The secondary flowline is isolated from the main flowline after the sensor responses have stabilized. A quality control procedure is performed on the fluid in the secondary flowline to determine whether the captured fluid is the same as the fluid in the main flowline. Additional fluid from the main flowline is allowed into the secondary flowline if the captured fluid is not the same.

Abstract: Methods and related systems are described for real-time wellsite production allocation analysis. Spectroscopic in-situ measurements are made in the vicinity of a wellsite of a produced fluid from one or more boreholes. The produced fluid includes in a co-mingled state, at least a first fluid component from a first production zone and a second fluid component from a second production zone. An allocation is estimated in real-time for at least the first fluid component in the produced fluid based at least in part on the spectroscopic in-situ measurements. The in-situ measurements can be several types, for example: (1) absorption of electromagnetic radiation having wavelengths in the range of ultraviolet, visible and/or infrared light, (2) X-ray fluorescence spectroscopy measurements, (3) electromagnetic scattering spectroscopic measurements such as Raman spectroscopy measurements, (4) NMR spectroscopy measurements, and (5) terahertz time-domain spectroscopy measurements.

Abstract: Methods and apparatuses for analyzing a downhole fluid are disclosed. An example method may involve the steps of admitting the downhole fluid in a test volume, controllably inducing a pressure change in the test volume based on at least one prescribed rate, measuring pressures in the test volume at a plurality of times, using the pressures measured at the plurality of times to determine a time at which an actual rate of the pressure change in the test volume deviates from the at least one prescribed rate, and detecting an occurrence of phase transition of the downhole fluid based on the determined time.

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 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 and correlating the fluorescence with other oil properties.

Abstract: Subsea apparatus and a method for sampling and analysing fluid from a subsea fluid flowline proximate a subsea well is provided, wherein the apparatus comprises at least one housing located in close proximity to said subsea fluid flowline; at least one fluid sampling device located in the housing in fluid communication with a said subsea fluid flowline for obtaining a sample of fluid from the subsea fluid flowline; at least one fluid processing apparatus located in the housing in fluid communication with said subsea fluid flowline for receiving and processing a portion of the fluid flowing through said fluid flowline or in fluid communication with the fluid sampling device, for processing the sample of fluid obtained from the subsea fluid flowline for analysis, while keeping the sample of fluid at subsea conditions; a fluid analysis device located in the housing, the fluid analysis device being in fluid communication with the fluid processing device and/or with the fluid sampling device, the fluid analysis de

Abstract: A gas separation and detection tool for performing in situ analysis of borehole fluid is described. A separation system such as a membrane is employed to separate one or more target gasses from the borehole fluid. The separated gas may be detected by reaction with another material or spectroscopy. When spectroscopy is employed, a test chamber defined by a housing is used to hold the gas undergoing test. Various techniques may be employed to protect the gas separation system from damage due to pressure differential. For example, a separation membrane may be integrated with layers that provide strength and rigidity. The integrated membrane separation may include one or more of a water impermeable layer, gas selective layer, inorganic base layer and metal support layer. The gas selective layer itself can also function as a water impermeable layer. The metal support layer enhances resistance to differential pressure. Alternatively, the chamber may be filled with a liquid or solid material.

Abstract: A downhole fluid analysis tool capable of fluid analysis during production logging that includes a phase separator and a plurality of sensors to perform analysis on the fluids collected at a subsurface location in a borehole.

Abstract: Methods and systems to characterize a fluid in a reservoir to determine if the fluid is in one of equilibrium or non-equilibrium in terms of one of gravity, solvency power, entropy effect or some combination thereof. The method includes acquiring tool data at each depth for each fluid sample of at least two fluid samples wherein each fluid sample is at a different depth and communicating the tool data to a processor. Determining formation properties of each fluid sample to obtain formation property data and determining fluid properties for each fluid sample to obtain fluid property data. Selecting a mathematical model based on one of gravity, solvency power or entropy, in view of a fluid property, using one of tool data, formation property data, fluid property data, known fluid reservoir data or some combination thereof, to predict if the fluid is in an equilibrium distribution or a non-equilibrium distribution.

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: A method and system for characterizing asphaltene gradients of a reservoir of interest and analyzing properties of the reservoir of interest based upon such asphaltene gradients. The analysis employs a correlation that relates insoluble asphaltene concentration to spectrophotometry measurement data measured at depth.

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.