Abstract: A method and system for determining a bed permeability. As disclosed, a fluid sampling tool may be disposed into a wellbore at a first location. The method may further include taking a drawdown and build up measurement with the fluid sampling tool, measuring a relative dip angle from the fluid sampling tool, calculating a bed anisotropy from the drawdown and build up measurement and the relative dip angle, calculating a bed mobility from the bed anisotropy, and calculating a bed permeability from the bed mobility and a viscosity.

Abstract: Methods for obtaining in-situ, multi-temperature measurements of fluid properties, such as saturation pressure and asphaltene onset pressure include obtaining a sample of formation fluid using a downhole acquisition tool positioned in a wellbore in a geological formation. The downhole acquisition tool may be stationed at a first depth in the wellbore that has an ambient first temperature. While stationed at the first depth, the downhole acquisition tool may test a first fluid property of the sample to obtain a first measurement point at approximately the first temperature. The downhole acquisition tool may be moved to a subsequent station at a new depth with an ambient second temperature, and another measurement point obtained at approximately the second temperature. From the measurement points, a temperature-dependent relationship of the first fluid property of the first formation fluid may be determined.

Abstract: Methods and downhole tools for operation within in a wellbore that extends into a subterranean formation. The operation includes simultaneously causing a change in a first parameter of fluid drawn into the downhole tool from the formation and determining a change in a second parameter of the fluid relative to the change in the first parameter. A third parameter of the fluid is determined based on the first and second parameter changes.

Abstract: Methods and downhole tools for operation within in a wellbore that extends into a subterranean formation. The operation includes simultaneously causing a change in a first parameter of fluid drawn into the downhole tool from the formation and determining a change in a second parameter of the fluid relative to the change in the first parameter. A third parameter of the fluid is determined based on the first and second parameter changes.

Abstract: Methods for obtaining in-situ, multi-temperature measurements of fluid properties, such as saturation pressure and asphaltene onset pressure, are provided. In one example, a sample of formation fluid is obtained using a downhole acquisition tool positioned in a wellbore in a geological formation. The downhole acquisition tool may be stationed at a first depth in the wellbore that has an ambient first temperature. While stationed at the first depth, the downhole acquisition tool may test a first fluid property of the sample to obtain a first measurement point at approximately the first temperature. The downhole acquisition tool may be moved to a subsequent station at a new depth with an ambient second temperature, and another measurement point obtained at approximately the second temperature. From the measurement points, a temperature-dependent relationship of the first fluid property of the first formation fluid may be determined.

Abstract: Methods for obtaining in-situ, multi-temperature measurements of fluid properties, such as saturation pressure and asphaltene onset pressure include obtaining a sample of formation fluid using a downhole acquisition tool positioned in a wellbore in a geological formation. The downhole acquisition tool may be stationed at a first depth in the wellbore that has an ambient first temperature. While stationed at the first depth, the downhole acquisition tool may test a first fluid property of the sample to obtain a first measurement point at approximately the first temperature. The downhole acquisition tool may be moved to a subsequent station at a new depth with an ambient second temperature, and another measurement point obtained at approximately the second temperature. From the measurement points, a temperature-dependent relationship of the first fluid property of the first formation fluid may be determined.

Abstract: Apparatus and methods for performing downhole testing. Example apparatus include a downhole tool string for conveying within a wellbore, the downhole tool string comprising an anchor device, a testing device, and a linear or rotary actuator. The anchor device maintains a portion of the downhole tool string in a predetermined position within the wellbore. The testing device is operable to receive a downhole sample from or test a subterranean formation surrounding the wellbore. The linear actuator is connected between the anchor device and testing device, and moves the testing device relative to the anchor device.

Abstract: Systems and methods for identifying a likelihood that a reservoir of a geological formation received a secondary charge of hydrocarbons of relatively very different thermal maturity of composition are provided. One method includes positioning a downhole acquisition tool in a wellbore in a geological formation and testing one or more fluid properties of the formation fluid. Data processing circuitry may identify whether a relationship of the one or more fluid properties exceeds a first threshold that indicates likely asphaltene instability. When this is the case, data processing circuitry may be used to model the geological formation using a realization scenario in which multiple charges of hydrocarbons of substantially different thermal maturity or substantially different composition, or both, filled a reservoir of the geological formation over geologic time.

Abstract: Systems and methods for identifying a likelihood that a reservoir of a geological formation received a secondary charge of hydrocarbons of relatively very different thermal maturity of composition are provided. One method includes positioning a downhole acquisition tool in a wellbore in a geological formation and testing one or more fluid properties of the formation fluid. Data processing circuitry may identify whether a relationship of the one or more fluid properties exceeds a first threshold that indicates likely asphaltene instability. When this is the case, data processing circuitry may be used to model the geological formation using a realization scenario in which multiple charges of hydrocarbons of substantially different thermal maturity or substantially different composition, or both, filled a reservoir of the geological formation over geologic time.

Abstract: The present disclosure relates to methods and apparatus for determining a gas-oil ratio based on downhole fluid analysis measurements and calibrated gas-oil ratio parameters. According to certain embodiments, the parameters for calculating the gas-oil ratio may be calibrated using historical data from the reservoir. For example, previously determined gas-oil ratios may be employed to calibrate the parameters to the reservoir. The calibrated parameters may then be employed during sampling operations to determine the gas-oil ratio.

Abstract: A formation sampling method includes disposing a downhole tool comprising a packer and an expandable probe within a wellbore. The method also includes performing pressure transient testing by setting the expandable packer and the probe to engage a wall of the wellbore and measuring a pressure response at the expandable packer and the probe while withdrawing formation fluid into the downhole tool through the expandable packer. The method further includes monitoring a contamination level of the formation fluid during the pressure transient testing, and performing formation sampling with the probe in response to determining that the monitored contamination level meets a predetermined threshold.

Abstract: Methods and downhole tools for operation within in a wellbore that extends into a subterranean formation. The operation includes simultaneously causing a change in a first parameter of fluid drawn into the downhole tool from the formation and determining a change in a second parameter of the fluid relative to the change in the first parameter. A third parameter of the fluid is determined based on the first and second parameter changes.

Abstract: Various implementations directed to analyzing a reservoir using fluid analysis are provided. In one implementation, a method may include determining mud gas logging (MGL) data based on drilling mud associated with a wellbore traversing a reservoir of interest. The method may also include determining first downhole fluid analysis (DFA) data based on a first reservoir fluid sample obtained at a first measurement station in the wellbore. The method may further include determining predicted DFA data for the wellbore based on the first DFA data. The method may additionally include determining second DFA data based on a second reservoir fluid sample obtained at a second measurement station in the wellbore. The method may further include analyzing the reservoir based on a comparison of the MGL data and a comparison of the second DFA data to the predicted DFA data.

Abstract: Apparatus and methods for performing downhole testing. Example apparatus include a downhole tool string for conveying within a wellbore, the downhole tool string comprising an anchor device, a testing device, and a linear or rotary actuator. The anchor device maintains a portion of the downhole tool string in a predetermined position within the wellbore. The testing device is operable to receive a downhole sample from or test a subterranean formation surrounding the wellbore. The linear actuator is connected between the anchor device and testing device, and moves the testing device relative to the anchor device.

Abstract: The present disclosure relates to systems and methods for determining an integrity of a sample chamber. In certain embodiments, formation fluid is collected from a subterranean formation within a sample chamber disposed in a downhole tool, the downhole tool is withdrawn from a wellbore, an estimated surface pressure of the collected formation fluid is determined, the estimated surface pressure of the collected formation fluid is compared with an actual surface pressure of the sample chamber, and the integrity of the sample chamber is determined based on the comparison of the estimated surface pressure and the actual surface pressure.

Abstract: Systems and methods for identifying a likelihood that a reservoir of a geological formation received a secondary charge of hydrocarbons of relatively very different thermal maturity of composition are provided. One method includes positioning a downhole acquisition tool in a wellbore in a geological formation and testing one or more fluid properties of the formation fluid. Data processing circuitry may identify whether a relationship of the one or more fluid properties exceeds a first threshold that indicates likely asphaltene instability. When this is the case, data processing circuitry may be used to model the geological formation using a realization scenario in which multiple charges of hydrocarbons of substantially different thermal maturity or substantially different composition, or both, filled a reservoir of the geological formation over geologic time.

Abstract: Methods for obtaining in-situ, multi-temperature measurements of fluid properties, such as saturation pressure and asphaltene onset pressure, are provided. In one example, a sample of formation fluid is obtained using a downhole acquisition tool positioned in a wellbore in a geological formation. The downhole acquisition tool may be stationed at a first depth in the wellbore that has an ambient first temperature. While stationed at the first depth, the downhole acquisition tool may test a first fluid property of the sample to obtain a first measurement point at approximately the first temperature. The downhole acquisition tool may be moved to a subsequent station at a new depth with an ambient second temperature, and another measurement point obtained at approximately the second temperature. From the measurement points, a temperature-dependent relationship of the first fluid property of the first formation fluid may be determined.

Abstract: The present disclosure relates to a formation sampling method that includes disposing a downhole tool comprising a packer and an expandable probe within a wellbore. The method also includes performing pressure transient testing by setting the expandable packer and the probe to engage a wall of the wellbore and measuring a pressure response at the expandable packer and the probe while withdrawing formation fluid into the downhole tool through the expandable packer. The method further includes monitoring a contamination level of the formation fluid during the pressure transient testing, and performing formation sampling with the probe in response to determining that the monitored contamination level meets a predetermined threshold.

Abstract: Various implementations directed to analyzing a reservoir using fluid analysis are provided. In one implementation, a method may include determining mud gas logging (MGL) data based on drilling mud associated with a wellbore traversing a reservoir of interest. The method may also include determining first downhole fluid analysis (DFA) data based on a first reservoir fluid sample obtained at a first measurement station in the wellbore. The method may further include determining predicted DFA data for the wellbore based on the first DFA data. The method may additionally include determining second DFA data based on a second reservoir fluid sample obtained at a second measurement station in the wellbore. The method may further include analyzing the reservoir based on a comparison of the MGL data and a comparison of the second DFA data to the predicted DFA data.

Abstract: The present disclosure relates to systems and methods for determining an integrity of a sample chamber. In certain embodiments, formation fluid is collected from a subterranean formation within a sample chamber disposed in a downhole tool, the downhole tool is withdrawn from a wellbore, an estimated surface pressure of the collected formation fluid is determined, the estimated surface pressure of the collected formation fluid is compared with an actual surface pressure of the sample chamber, and the integrity of the sample chamber is determined based on the comparison of the estimated surface pressure and the actual surface pressure.