Abstract: A method and a system are provided for allowing determination of a direction and distance from a tool to anomaly in a formation. The apparatus for performing the method includes at least one transmitter and at least one receiver. An embodiment of the method includes transmitting electromagnetic signals from the at least one transmitter through the formation near the wellbore and detecting responses at the at least one receiver induced by the electromagnetic signals. The method may further include determining the direction from the device to the anomaly based on the detected responses. The method may also include calculating at least one of an apparent azimuth angle and an apparent dip angle based on the responses, monitoring the at least one calculated apparent angle over time, and determining the direction to the anomaly after the at least one monitored apparent angle deviates from a zero value.

Abstract: A method and a system are provided for allowing determination of a direction and distance from a tool to anomaly in a formation. The apparatus for performing the method includes at least one transmitter and at least one receiver. An embodiment of the method includes transmitting electromagnetic signals from the at least one transmitter through the formation near the wellbore and detecting responses at the at least one receiver induced by the electromagnetic signals. The method may further include determining the direction from the device to the anomaly based on the detected responses. The method may also include calculating at least one of an apparent azimuth angle and an apparent dip angle based on the responses, monitoring the at least one calculated apparent angle over time, and determining the direction to the anomaly after the at least one monitored apparent angle deviates from a zero value.

Abstract: A method and a system are provided for allowing determination of a direction and distance from a tool to anomaly in a formation. The apparatus for performing the method includes at least one transmitter and at least one receiver. An embodiment of the method includes transmitting electromagnetic signals from the at least one transmitter through the formation near the wellbore and detecting responses at the at least one receiver induced by the electromagnetic signals. The method may further include determining the direction from the device to the anomaly based on the detected responses. The method may also include calculating at least one of an apparent azimuth angle and an apparent dip angle based on the responses, monitoring the at least one calculated apparent angle over time, and determining the direction to the anomaly after the at least one monitored apparent angle deviates from a zero value.

Abstract: Method of analyzing a subterranean formation traversed by a wellbore. The method uses a tool comprising a transmitter antenna and a receiver antenna, the subterranean formation comprising one or more formation layers. The tool is suspended inside the wellbore, and one or more electromagnetic fields are induced in the formation. One or more time-dependent transient response signals are detected and analyzed. Electromagnetic anisotropy of at least one of the formation layers is detectable. Geosteering cues may be derived from the time-dependent transient response signals, for continued drilling of the well bore until a hydrocarbon reservoir is reached. The hydrocarbon may then be produced.

Abstract: An electromagnetic response from a region in an earth formation is determined by lowering an electromagnetic measurement tool into a borehole in the earth formation. The tool comprises a transmitter antenna, a receiver antenna, and an electrically conductive support structure. The transmitter antenna is energized, resulting in receiver signal in the receiver antenna. A raw response signal, comprising the receiver signal, is measured at the receiver antenna. The raw response signal is adjusted using a reference signal obtained by measuring the response signal of the tool in a test environment having a resistivity that is higher than that of the region in the earth formation. This method can be employed during the drilling of the borehole which may be part of a method of producing a mineral hydrocarbon fluid.

Abstract: Method for data acquisition and processing, which uses time-domain averaging to increase the signal to noise ratio (SNR) in single-event measurements. In a preferred embodiment, NMR echo-trains obtained using high-speed NMR logging are provided, the echo trains are time-domain averaged, preferably in real-time, over one or more time intervals to sharpen the spatial resolution of the logging tool and/or to increase the signal to noise ratio (SNR) of the data train.

Abstract: A method and a system are provided for allowing determination of a direction and distance from a tool to anomaly in a formation. The apparatus for performing the method includes at least one transmitter and at least one receiver. An embodiment of the method includes transmitting electromagnetic signals from the at least one transmitter through the formation near the wellbore and detecting responses at the at least one receiver induced by the electromagnetic signals. The method may further include determining the direction from the device to the anomaly based on the detected responses. The method may also include calculating at least one of an apparent azimuth angle and an apparent dip angle based on the responses, monitoring the at least one calculated apparent angle over time, and determining the direction to the anomaly after the at least one monitored apparent angle deviates from a zero value.

Abstract: A method and a system are provided for allowing determination of a direction and distance from a tool to anomaly in a formation. The apparatus for performing the method includes at least one transmitter and at least one receiver. An embodiment of the method includes transmitting electromagnetic signals from the at least one transmitter through the formation near the wellbore and detecting responses at the at least one receiver induced by the electromagnetic signals. The method may further include determining the direction from the device to the anomaly based on the detected responses. The method may also include calculating at least one of an apparent azimuth angle and an apparent dip angle based on the responses, monitoring the at least one calculated apparent angle over time, and determining the direction to the anomaly after the at least one monitored apparent angle deviates from a zero value.

Abstract: A method and a system are provided for allowing determination of a direction and distance from a tool to anomaly in a formation. The apparatus for performing the method includes at least one transmitter and at least one receiver. An embodiment of the method includes transmitting electromagnetic signals from the at least one transmitter through the formation near the wellbore and detecting responses at the at least one receiver induced by the electromagnetic signals. The method may further include determining the direction from the device to the anomaly based on the detected responses. The method may also include calculating at least one of an apparent azimuth angle and an apparent dip angle based on the responses, monitoring the at least one calculated apparent angle over time, and determining the direction to the anomaly after the at least one monitored apparent angle deviates from a zero value.

Abstract: A method of imaging a subterranean formation traversed by a wellbore using a tool comprising a transmitter for transmitting electromagnetic signals through the formation and a receiver for detecting response signals. The tool is brought to a first position inside the wellbore, and the transmitter is energized to propagate an electromagnetic signal into the formation. A response signal that has propagated through the formation is detected. A derived quantity for the formation based on the detected response signal for the formation is calculated, and plotted against time. The tool may be moved to at least one other position within the wellbore where the procedure may be repeated to create an image of the formation within the subterranean formation based on the plots.

Abstract: A method and a system are provided for allowing determination of a distance from a tool to anomaly ahead of the tool. The apparatus for performing the method includes at least one transmitter and at least one receiver. An embodiment of the method includes transmitting electromagnetic signals from the at least one transmitter through the formation surrounding the wellbore and detecting voltage responses at the at least one receiver induced by the electromagnetic signals. The method includes calculating apparent conductivity or apparent resistivity based on a voltage response. The conductivity or resistivity is monitored over time, and the distance to the anomaly is determined from the apparent conductivity or apparent resistivity values.

Abstract: A method and a system are provided for allowing determination of a direction and distance from a tool to anomaly in a formation. The apparatus for performing the method includes at least one transmitter and at least one receiver. An embodiment of the method includes transmitting electromagnetic signals from the at least one transmitter through the formation near the wellbore and detecting responses at the at least one receiver induced by the electromagnetic signals. The method may further include determining the direction from the device to the anomaly based on the detected responses. The method may also include calculating at least one of an apparent azimuth angle and an apparent dip angle based on the responses, monitoring the at least one calculated apparent angle over time, and determining the direction to the anomaly after the at least one monitored apparent angle deviates from a zero value.

Abstract: A method for determining the anisotropic resistivity properties of a subterranean formation traversed by a borehole utilizing a multi-component induction logging tool. The method utilizes the measured phase and attenuation signals induced by eddy currents in the formation to determine the azimuthal angle and to create a second set of signals based on the measured signals and the azimuthal angle. The anisotropic resistive properties, as well as the dip angle, are then simultaneously derived from the second set of signals by means of minimizing error functions within an inversion model.

Abstract: A method of compensating for tool motion is disclosed. In one embodiment, the method includes passing a logging tool through a borehole, obtaining a series of tool response measurements, and obtaining a series of tool position measurements associated with the tool response measurements. The tool position measurements preferably indicate the distance between the tool axis and the borehole axis. The tool position measurements are preferably examined to determine if the tool was moving while the tool was making measurements. For measurements made while the tool was moving, the measurement time interval is preferably divided into subintervals each having a corresponding tool position. A formation property (such as resistivity) is estimated, and the expected tool response for each tool position is calculated. The expected tool responses are combined to form a model tool response, that is, the tool response that might be expected for a tool in motion.

Abstract: A new method for determining the anisotropic resistivity properties of a subterranean earth formation traversed by a borehole utilizing a multi-component induction logging tool. The method utilizes the phase and attenuation signals induced by eddy currents in the formation to determine the resistive properties, with or without prior knowledge of the borehole dip angle.

Abstract: Method for data acquisition and processing, which uses time-domain averaging to increase the signal to noise ratio (SNR) in single-event measurements. In a preferred embodiment, NMR echo-trains obtained using high-speed NMR logging are provided, the echo trains are time-domain averaged, preferably in real-time, over one or more time intervals to sharpen the spatial resolution of the logging tool and/or to increase the signal to noise ratio (SNR) of the data train.

Abstract: A method of compensating for tool motion is disclosed. In one embodiment, the method includes passing a logging tool through a borehole, obtaining a series of tool response measurements, and obtaining a series of tool position measurements associated with the tool response measurements. The tool position measurements preferably indicate the distance between the tool axis and the borehole axis. The tool position measurements are preferably examined to determine if the tool was moving while the tool was making measurements. For measurements made while the tool was moving, the measurement time interval is preferably divided into subintervals each having a corresponding tool position. A formation property (such as resistivity) is estimated, and the expected tool response for each tool position is calculated. The expected tool responses are combined to form a model tool response, that is, the tool response that might be expected for a tool in motion.

Abstract: A method for enhancing measurement resolution is disclosed. In one embodiment, the method includes (1) obtaining multiple measurement samples at each of multiple positions along a borehole; (2) extracting reference index samples from the set of measurement samples; (3) determining a difference between each of the reference index samples and corresponding modeled index samples; and (4) updating a set of enhanced index samples based on the difference. The index samples are preferably chosen to be representative of the measurement samples obtained at each position, and accordingly, may be selected ones of the measurement samples, or alternatively, may be averages of the measurement samples. The aforementioned modeled index samples may be found from application of a predetermined tool response to the enhanced index samples, which in turn, may be found by iteration.

Abstract: An interpretation method and system for NMR echo-train data in thinly laminated sequences. The invention uses geological information obtained at higher vertical resolution, such as using Electric Micro Imaging, to enhance the vertical resolution of echo-train data, and thus avoids log interpretations in which the hydrocarbon potential of the formation can be misread because low resolution logs tend to provide an average description of the formation. Such averaging is especially problematic in thinly laminated sequences that consist of highly permeable and porous sand layers and less permeable silt or essentially impermeable shale layers. In a preferred embodiment, using the additional high-resolution formation information one can estimate the typical T2-spectra of lithological laminae, and significantly enhance the permeability estimate in the laminated sequences.

Abstract: An interpretation method and system for NMR echo-train data in thinly laminated sequences. The invention uses geological information obtained at higher vertical resolution, such as using Electric Micro Imaging, to enhance the vertical resolution of echo-train data, and thus avoids log interpretations in which the hydrocarbon potential of the formation can be misread because low resolution logs tend to provide an average description of the formation. Such averaging is especially problematic in thinly laminated sequences that consist of highly permeable and porous sand layers and less permeable silt or essentially impermeable shale layers. In a preferred embodiment, using the additional high-resolution formation information one can estimate the typical T2-spectra of lithological laminae, and significantly enhance the permeability estimate in the laminated sequences. The method and system are applicable to any temporal data from other logging tools, such as the thermal neutron decay log and others.