Abstract: A method includes positioning a downhole acquisition tool in a wellbore in a geological formation. The method includes operating a pump module to gather information for a fluid outside of the downhole acquisition tool that enters the downhole acquisition tool from a first flowline, a second flowline, or both while the downhole acquisition tool is within the wellbore. Operating the pump module includes controlling a valve assembly to a first valve configuration that enables the fluid to flow into the downhole tool via the first flowline fluidly coupled to a first pump module.

Abstract: A method for sampling a downhole formation fluid includes pumping formation fluid into the flowline of a downhole sampling tool While pumping, a saturation pressure of the formation fluid is measured. The pumping rate is adjusted such that the fluid pressure in the flowline remains above a threshold saturation pressure.

Abstract: Apparatus and methods for obtaining initial settings of station-specific parameters descriptive of wellbore/formation properties specific to downhole pressure test stations, and obtaining initial settings of station-shared parameters descriptive of petrophysical properties of petrophysically unique formation zones. A pressure transient model of the zones is obtained by regression utilizing the pressure data of each station and the initial settings of the station-specific and station-shared parameters. The regression analytically determines a model value of at least one of the station-specific parameters and the station-shared parameters.

Abstract: A method includes positioning a downhole acquisition tool in a wellbore in a geological formation. The method includes operating a pump module to gather information for a fluid outside of the downhole acquisition tool that enters the downhole acquisition tool from a first flowline, a second flowline, or both while the downhole acquisition tool is within the wellbore. Operating the pump module includes controlling a valve assembly to a first valve configuration that enables the fluid to flow into the downhole tool via the first flowline fluidly coupled to a first pump module.

Abstract: A method for sampling a downhole formation fluid includes pumping formation fluid into the flowline of a downhole sampling tool, measuring a saturation pressure of the formation fluid in the flowline while pumping, and adjusting the pumping rate such that the fluid pressure in the flowline remains within a predetermined threshold above the measured saturation pressure.

Abstract: A method includes positioning a downhole acquisition tool in a wellbore in a geological formation. The method includes operating a pump module to gather information for a fluid outside of the downhole acquisition tool that enters the downhole acquisition tool from a first flowline, a second flowline, or both while the downhole acquisition tool is within the wellbore. Operating the pump module includes controlling a valve assembly to a first valve configuration that enables the fluid to flow into the downhole tool via the first flowline fluidly coupled to a first pump module.

Abstract: A method for sampling a downhole formation fluid includes pumping formation fluid into the flowline of a downhole sampling tool, measuring a saturation pressure of the formation fluid in the flowline while pumping, and adjusting the pumping rate such that the fluid pressure in the flowline remains within a predetermined threshold above the measured saturation pressure.

Abstract: A method for sampling a downhole formation fluid includes pumping formation fluid into the flowline of a downhole sampling tool, measuring a saturation pressure of the formation fluid in the flowline while pumping, and adjusting the pumping rate such that the fluid pressure in the flowline remains within a predetermined threshold above the measured saturation pressure.

Abstract: A method for measuring asphaltene content of a crude oil is provided. In one embodiment, the method includes measuring an optical density of a live crude oil within a well and calculating a formation volume factor of the live crude oil based on the measured optical density. The method also includes determining asphaltene content of the live crude oil based on the measured optical density and the calculated formation volume factor of the live crude oil. Additional methods, systems, and devices are also disclosed.

Abstract: A method for sampling a downhole formation fluid includes pumping formation fluid into the flowline of a downhole sampling tool. The method can also include measuring a saturation pressure of the formation fluid in the flowline while pumping. The method can also include adjusting the pumping rate such that the fluid pressure in the flowline remains within a predetermined threshold above the measured saturation pressure.

Abstract: A method includes positioning a downhole acquisition tool in a well-logging device in a wellbore in a geological formation, where the wellbore or the geological formation, or both contain a reservoir fluid. The method includes performing downhole fluid analysis using a downhole acquisition tool in the wellbore to determine a plurality of fluid properties associated with the reservoir fluid. The method includes generating a nonlinear predictive control model representative of the plurality of fluid properties based at least in part on the downhole fluid analysis. The method includes adjusting the nonlinear predictive control model based at least in part on an output representative of a pump flow control sequence at a first time interval and the plurality of fluid properties.

Abstract: A method includes operating a downhole acquisition tool in a wellbore in a geological formation. The wellbore or the geological formation, or both, contain a reservoir fluid. The method also includes receiving a portion of the reservoir fluid into the downhole acquisition tool and performing downhole fluid analysis using the downhole acquisition tool in the wellbore to determine at least one measurement associated with the portion of the reservoir fluid. The at least one measurement includes fluid density, optical density, or both. The method also includes using a processor of the downhole acquisition tool to obtain compressibility of the reservoir fluid based at least in part on the fluid density, the optical density, or both and determining a composition of the reservoir fluid based at least in part on the compressibility.

Abstract: A method for sampling a downhole formation fluid that includes pumping formation fluid into the flowline of a downhole sampling tool. The method also includes measuring a saturation pressure of the formation fluid in the flowline while pumping, and adjusting the pumping rate such that the fluid pressure in the flowline remains within a predetermined threshold above the measured saturation pressure.

Abstract: A method for determining formation fluid sample quality includes analyzing sample capture data to identify distinguishing features indicative of whether a successful sample capture has occurred within a downhole tool. The method further includes prioritizing, based on the analysis, the sample capture data for transmission to a surface system.

Abstract: Formation fluid sample container apparatus are described. An example apparatus includes a downhole tool having a body including an opening and a cavity extending into the body from the opening. The sample container includes an elongated container for holding a formation fluid sample and a sheath coupled to an outer surface of the elongated container and at least partially surrounding the elongated container. The sample container is fixed in the cavity and the sheath is to increase the mechanical integrity of the elongated container in a downhole environment.

Abstract: Obtaining in-situ, at a first time, first optical spectral data associated with a formation fluid flowing through a downhole formation fluid sampling apparatus, and then obtaining in-situ, at a second time after the first time, second optical spectral data associated with the formation fluid flowing through the downhole formation fluid sampling apparatus. A wavelength-independent scattering intensity within the formation fluid flowing through the downhole formation fluid sampling apparatus is then determined based on the first and second optical spectral data, and a wavelength-dependent scattering intensity within the formation fluid flowing through the downhole formation fluid sampling apparatus is determined based on the first and second optical spectral data.

Abstract: According to certain embodiments, formation fluid properties, such as gas-oil ratio (GOR), formation volume factor (FVF), and density, may be measured at multiple times during sampling. In one embodiment, data representing the measured properties is analyzed and a characteristic of interest is determined through extrapolation from the analyzed data. Various other methods and systems are also disclosed.

Abstract: A method for contamination monitoring includes measuring water based mud filtrate density and resistivity at downhole conditions, logging properties of a downhole fluid to find at least a resistivity and a density of a fluid sample at the downhole conditions, establishing a linear relationship between a water based mud filtrate conductivity at downhole conditions and the water based mud filtrate density at the downhole conditions, determining a density and a resistivity for native formation water, estimating a density for water based mud filtrate using the linear relationship between conductivity and density, and estimating a water based mud filtrate contamination.

Abstract: A downhole fluid testing system includes a downhole acquisition tool housing configured to be moved into a wellbore, where the wellbore contains fluid that comprises a native reservoir fluid of a geological formation and a contaminant. The system includes a pump to pump fluid through the downhole acquisition tool, a sensor configured to analyze portions of the fluid and obtain a fluid property the fluid from an optical spectrometer, including an optical density, and a controller coupled to the housing to receive a first plurality of measurements over time from the sensor, estimate a future saturation pressure of the fluid at specific time increments via a processor based in part on the first plurality of measurements and a saturation pressure model, and control a flow rate of the pump that causes the flow line pressure to remain above the estimated future saturation pressure plus a value of the associated uncertainty.

Abstract: An optical spectrometer includes a near black body light source, a reference detector in a first optical path and a single measurement detector in a second optical path. A sample cell including a fluid flow line may be positioned in the second optical path upstream of the measurement detector. Optical energy may be emitted at a plurality of filament temperatures and first and second sets of optical intensities measured at the reference and measurement detectors. The first and second sets of optical intensities may be processed to compute a substantially continuous transmittance spectrum of a fluid sample in the fluid flow line by inverting the acquired optical intensity measurements.