Abstract: An apparatus for evaluating downhole fluids is disclosed. The apparatus includes: an optical block having an adjustable opening that receives electromagnetic energy emitted by an electromagnetic energy source; a controller operatively associated with the optical block for adjusting the opening size, wherein the opening size is adjusted at least in part based on one or more estimated downhole parameters; and a sensor that receives the electromagnetic energy emitted by the electromagnetic energy source after the emitted electromagnetic energy interacts with a downhole fluid. A method for evaluating downhole fluids is also disclosed.

Abstract: A method for conducting a formation test includes providing a volume change model for a tool component, and providing a control program that uses the volume change model to estimate a system volume change resulting from a change in the tool component during a downhole operation. An apparatus for conducting a formation test includes a carrier, a formation test tool, a measurement device that estimates a change in a tool component during operation, and a processor that uses a volume change model to estimate a system volume change resulting at least in part from the change in the tool component during a downhole operation.

Abstract: A method for measuring optical properties of a fluid downhole, the method comprising measuring intensity of light interacting with the fluid downhole for each of one or more wavelengths; integrating each intensity of light for each wavelength for an integration time; and estimating the optical property from a difference between a starting value and an ending value for the integral of the intensity of light over time divided by the integration time for the wavelength. An apparatus is disclosed for measuring an optical property of a fluid downhole, the apparatus comprising one or more photodiodes that measure an intensity of light interacting with the fluid downhole for each of one or more wavelengths; and one or more integration circuits that each integrates an intensity of light for one wavelength for an integration time.

Abstract: Measurements of fluorescence spectra of fluid samples recovered downhole are processed to give the fluid composition. The processing may include a principal component analysis followed by a clustering method or a neutral network. Alternatively the processing may include a partial least squares regression. The latter can give the analysis of a mixture of three or more fluids.

Abstract: A method is disclosed for measuring optical properties of a fluid downhole, the method comprising measuring intensity of light interacting with the fluid downhole for each of one or more wavelengths; integrating each intensity of light for each wavelength for an integration time; and estimating the optical property from a difference between a starting value and an ending value for the integral of the intensity of light over time divided by the integration time for the wavelength. An apparatus is disclosed for measuring an optical property of a fluid downhole, the apparatus comprising one or more photodiodes that measure an intensity of light interacting with the fluid downhole for each of one or more wavelengths; and one or more integration circuits that each integrates an intensity of light for one wavelength for an integration time.

Abstract: A method includes calculating a correction factor that uses a tool component volume change model to estimate a system volume change resulting from a change in the tool component. An apparatus includes a carrier conveyable into a well borehole, a formation test tool coupled to the carrier, the formation test tool including a tool component. A measurement device to estimate a change in the tool component during operation, and a compensator uses an estimated system volume change resulting at least in part from the change in the tool component during a downhole operation, the compensator compensating for the system volume change and wherein the estimated system volume change is estimated at least in part using a volume change model.

Abstract: A method and apparatus for of determining a formation parameter of interest. The method includes placing a tool into communication with the formation to test the formation and drawing down a test volume at an increasing draw rate during a first draw period and decreasing the draw rate during a second draw period to create a smooth draw down cycle. The draw down can be step-wise or continuous. The formation parameter is determined using formation rate analyis and characteristics determined during the draw down cycle.

Abstract: A method for conducting a formation test includes providing a volume change model for a tool component, and providing a control program that uses the volume change model to estimate a system volume change resulting from a change in the tool component during a downhole operation. An apparatus for conducting a formation test includes a carrier, a formation test tool, a measurement device that estimates a change in a tool component during operation, and a processor that uses a volume change model to estimate a system volume change resulting at least in part from the change in the tool component during a downhole operation.

Abstract: A method and apparatus for of determining a formation parameter of interest. The method includes placing a tool into communication with the formation to test the formation and drawing down a test volume at an increasing draw rate during a first draw period and decreasing the draw rate during a second draw period to create a smooth draw down cycle. The draw down can be step-wise or continuous. The formation parameter is determined using formation rate analyis and characteristics determined during the draw down cycle.