Abstract: Methods and systems are described for estimating of the level of contamination of downhole fluid using physical property measurements, and mathematical modeling of contamination functions and fluid property mixing laws. The proposed approaches enable computation of estimates of the pumping time needed to achieve a certain contamination threshold level.

Abstract: This application relates to various methods and apparatus for rapidly obtaining accurate formation property data from a drilled earthen borehole. Once obtained, the formation property data, including formation fluid pressure, may be corrected, calibrated and supplemented using various other data and techniques disclosed herein. Furthermore, the formation property data may be used for numerous other purposes. For example, the data may be used to correct or supplement other information gathered from the borehole; it may be used to supplement formation images or models; or, it may be used to adjust a drilling or producing parameter. Various other uses of accurately and quickly obtained formation property data are also disclosed.

Abstract: A method for determining the composition of a fluid by using measured properties of the fluid. One embodiment of the method of the current invention generally comprises: selecting a fluid property that has a response to fluid composition that is linear, or can be approximated as linear; measuring the selected fluid property at a series of specific time intervals; and plotting the measured property as a function of the selected property. In effect, plotting the measured property as a function of fluid composition in an arbitrary set of units. This allows for a in-situ qualitative evaluation of fluid composition by measuring a fluid property that has a known linear relationship to fluid composition. Another embodiment of the present invention further comprises, establishing the endpoints of contamination and plotting the measured properties through these endpoints. Once the endpoints have been established a quantitative evaluation of the fluid composition can be performed.

Abstract: A method of determining the supercharge pressure in a formation intersected by a borehole having a wall, the method comprising disposing a formation pressure test tool into the borehole having a probe for isolating a portion of the borehole. The method further comprises extending the probe into sealing contact with the borehole wall. The method further comprises performing at least one drawdown test with the formation pressure test tool. The method further comprises modeling the supercharge pressure of the formation using the dynamic properties of the mudcake. The method further comprises determining the supercharge pressure of the formation using the supercharge pressure model. The formation pressure test tool may be conveyed into the borehole using wireline technology or on a drill string. Using the supercharge pressure, the drawdown test may be optimized, the characteristics of the drilling fluid altered, or the measurements of other sensors adjusted.

Abstract: System and methods for estimating properties of a geologic formation are disclosed. A preferred embodiment includes a method for estimating properties of a geologic formation, comprising the steps of: measuring a property of the formation in two or more directions along a path in the formation; obtaining directional property values for at least one spatial unit along the path in the formation based on the property measurements; and providing an anisotropy estimate of the formation from the obtained directional property values.

Abstract: A method for generating acoustic waves, the method having the steps of: extending a tine from a support structure so that a proximal end of the tine is attached to the support structure and a distal end of the tine is uninhibited; positioning an oscillator so as to be supported by the support structure and to mechanically communicate with the tine; and oscillating the tine with the oscillator.

Abstract: A method of testing a downhole formation using a formation tester on a drill string. The formation tester is disposed downhole on a drill string and a formation test is performed by forming a seal between a formation probe assembly and the formation. A drawdown piston then creates a volume within a cylinder to draw formation fluid into the volume through the probe assembly. The pressure of the fluid within the cylinder is monitored. The formation test procedure may then be adjusted. The test procedure may be adjusted to account for the bubble point pressure of the fluid being monitored. The pressure may monitored to verify a proper seal is formed or is being maintained. The test procedure may also be performed by maintaining a substantially constant drawdown rate using a hydraulic threshold or a variable restrictor.

Abstract: An apparatus for generating acoustic waves, the apparatus having: a support structure; two tines extending from the support structure so that proximal ends of the two tines are attached to the support structure so that distal ends of the two tines are positioned with standoffs relative to a dimension of the support structure and the distal ends of the two tines are uninhibited, wherein the two tines each comprise a moment arm; and an oscillator in mechanical communication with the two tines.

Abstract: Systems and methods for downhole formation testing based on the use of one or more elongated sealing pads capable of sealing off and collecting or injecting fluids from elongated portions along the surface of a borehole. The modified sealing pads increase the flow area by collecting fluids from an extended portion along the surface of a borehole, which is likely to straddle one or more layers in laminated or fractured formations. A tester device using the elongated sealing pads can be deployed and withdrawn using an extendible element pressing the pads to the borehole. Various designs and arrangements for use with a fluid tester, which may be part of a modular fluid tool, are disclosed in accordance with different embodiments.

Abstract: A method and system for statistical pressure gradient and fluid contact analysis. The method and system include planning for a pressure gradient test by using expected parameters and statistical expected error analysis to set the actual pressure gradient test parameters within an acceptable range of reliability. The method and system may account for one or more fluids within a formation and may also perform fluid contact analysis as part of planning the overall pressure gradient test. The method and system also include performing the planned pressure gradient test and comparing the measured data and statistical measured data error analysis with statistical expected error analysis of the measured data.

Abstract: Methods and systems are described for estimating of the level of contamination of downhole fluid using physical property measurements, and mathematical modeling of contamination functions and fluid property mixing laws. The proposed approaches enable computation of estimates of the pumping time needed to achieve a certain contamination threshold level.

Abstract: Systems and methods for downhole formation testing based on the use of one or more elongated sealing pads capable off sealing off and collecting or injecting fluids from elongated portions along the surface of a borehole. The modified sealing pads increase the flow area by collecting fluids from an extended portion along the surface of a borehole, which is likely to straddle one or more layers in laminated or fractured formations. A tester device using the elongated sealing pads can be deployed and withdrawn using an extendible element pressing the pads to the borehole. Various designs and arrangements for use with a fluid tester, which may be part of a modular fluid tool, are disclosed in accordance with different embodiments.

Abstract: An apparatus for generating acoustic waves, the apparatus having: a support structure; two tines extending from the support structure so that proximal ends of the two tines are attached to the support structure so that distal ends of the two tines are positioned with standoffs relative to a dimension of the support structure and the distal ends of the two tines are uninhibited, wherein the two tines each comprise a moment arm; and an oscillator in mechanical communication with the two tines.

Abstract: A method for generating acoustic waves, the method having the steps of: extending a tine from a support structure so that a proximal end of the tine is attached to the support structure and a distal end of the tine is uninhibited; positioning an oscillator so as to be supported by the support structure and to mechanically communicate with the tine; and oscillating the tine with the oscillator.

Abstract: The specification discloses a downhole tool that determines hydraulic permeability of a downhole formation taking into account one or both of the dip angle of the borehole relative to the formation, and damage to the borehole wall and invasion of borehole fluid—collectively referred to as skin.

Abstract: Methods for operating multi-probed formation testers to determine a fluid density gradient in the formation. The probes of the multi-probed formation tester are connected to a pressure gauge through a flowline that establishes a differential height between the probes. In some embodiments, a gradient of the fluid density in the flowline is determined as a function of the gradient of fluid density in the wellbore. The flowline fluid density gradient is then used to determine a formation fluid density gradient as a function of the flowline fluid density gradient.

Abstract: A method of testing a downhole formation using a formation tester on a drill string. The formation tester is disposed downhole on a drill string and a formation test is performed by forming a seal between a formation probe assembly and the formation. A drawdown piston then creates a volume within a cylinder to draw formation fluid into the volume through the probe assembly. The pressure of the fluid within the cylinder is monitored. The formation test procedure may then be adjusted. The test procedure may be adjusted to account for the bubble point pressure of the fluid being monitored. The pressure may monitored to verify a proper seal is formed or is being maintained. The test procedure may also be performed by maintaining a substantially constant drawdown rate using a hydraulic threshold or a variable restrictor.

Abstract: This application relates to various methods and apparatus for rapidly obtaining accurate formation property data from a drilled earthen borehole. Once obtained, the formation property data, including formation fluid pressure, may be corrected, calibrated and supplemented using various other data and techniques disclosed herein. Furthermore, the formation property data may be used for numerous other purposes. For example, the data may be used to correct or supplement other information gathered from the borehole; it may be used to supplement formation images or models; or, it may be used to adjust a drilling or producing parameter. Various other uses of accurately and quickly obtained formation property data are also disclosed.

Abstract: This application relates to various methods and apparatus for rapidly obtaining accurate formation property data from a drilled earthen borehole. Quickly obtaining accurate formation property data, including formation fluid pressure, is vital to beneficially describing the various formations being intersected. For example, methods are disclosed for collecting numerous property values with a minimum of downhole tools, correcting and calibrating downhole measurements and sensors, and developing complete formation predictors and models by acquiring a diverse set of direct formation measurements, such as formation fluid pressure and temperature. Also disclosed are various methods of using of accurately and quickly obtained formation property data.

Abstract: A method of determining the supercharge pressure in a formation intersected by a borehole having a wall, the method comprising disposing a formation pressure test tool into the borehole having a probe for isolating a portion of the borehole. The method further comprises extending the probe into sealing contact with the borehole wall. The method further comprises performing at least one drawdown test with the formation pressure test tool. The method further comprises modeling the supercharge pressure of the formation using the dynamic properties of the mudcake. The method further comprises determining the supercharge pressure of the formation using the supercharge pressure model. The formation pressure test tool may be conveyed into the borehole using wireline technology or on a drill string. Using the supercharge pressure, the drawdown test may be optimized, the characteristics of the drilling fluid altered, or the measurements of other sensors adjusted.