Patent classifications
G01V3/32
INTELLIGENT DATA ACQUISITION FOR WIRELINE LOGGING
Methods and systems are provided for optimizing well-logging using an optimized wait time determined by analysis nuclear magnetic resonance data to achieve faster and better quality borehole evaluation. The method comprises performing a nuclear magnetic resonance pre-log testing; identifying a wait time for a portion of a signal from the pre-log testing with a long T1 and T2, value at each depth of the pre-log testing, wherein T1 is defined as a longitudinal relaxation time and T2 is a transverse relaxation time ascertained from the nuclear magnetic resonance prelog testing; and constructing a logging program with a logging program wait time being consistent with the wait time identified.
INTELLIGENT DATA ACQUISITION FOR WIRELINE LOGGING
Methods and systems are provided for optimizing well-logging using an optimized wait time determined by analysis nuclear magnetic resonance data to achieve faster and better quality borehole evaluation. The method comprises performing a nuclear magnetic resonance pre-log testing; identifying a wait time for a portion of a signal from the pre-log testing with a long T1 and T2, value at each depth of the pre-log testing, wherein T1 is defined as a longitudinal relaxation time and T2 is a transverse relaxation time ascertained from the nuclear magnetic resonance prelog testing; and constructing a logging program with a logging program wait time being consistent with the wait time identified.
CORRECTION OF NUCLEAR MAGNETIC RESONANCE DATA IN HIGH VIBRATION ENVIRONMENTS
Described herein are methods for removing the vibration induced additional signal obtained during downhole NMR operations. The additional signal is removed by analyzing a number of instances of data sets neighbors, at either the raw echo, reconstructed echoes, or the spectrum which results from inversion. A number of neighboring data instances are analyzed together to find the minimal (lowest) common values in each. Thereafter, the minimal value replaces the previous value across the data instances, thereby removing the extra signal.
CORRECTION OF NUCLEAR MAGNETIC RESONANCE DATA IN HIGH VIBRATION ENVIRONMENTS
Described herein are methods for removing the vibration induced additional signal obtained during downhole NMR operations. The additional signal is removed by analyzing a number of instances of data sets neighbors, at either the raw echo, reconstructed echoes, or the spectrum which results from inversion. A number of neighboring data instances are analyzed together to find the minimal (lowest) common values in each. Thereafter, the minimal value replaces the previous value across the data instances, thereby removing the extra signal.
Drilling Quasi-Stationary Data Extraction And Processing
A method for assessing and/or removing one or more motion effects from logging while drilling (LWD) measurement data may include disposing a borehole logging tool into a borehole, wherein the borehole logging tool is disposed on a bottom hole assembly (BHA), taking one or more measurements at one or more depth in the borehole with the borehole logging tool to form a measurement data set, and identifying one or more pipe breaks and one or more stations in the measurement data set. The method extracts measurement data at one or more pipe breaks and one or more stations to form a non-motion measurement data set, providing answer products from the non-motion measurement data set. The method may further include removing the one or more pipe breaks and one or more stations from the measurement data set to form a corrected measurement data set and providing one or more answer products.
Downhole NMR system
A method can include triggering an assessment of pulse width of an X degree pulse of a downhole NMR tool; responsive to the assessment, determining an optimal pulse width of the X degree pulse; acquiring NMR measurements using the downhole NMR tool and the optimal pulse width; and characterizing a formation using at least a portion of the NMR measurements.
Downhole NMR system
A method can include triggering an assessment of pulse width of an X degree pulse of a downhole NMR tool; responsive to the assessment, determining an optimal pulse width of the X degree pulse; acquiring NMR measurements using the downhole NMR tool and the optimal pulse width; and characterizing a formation using at least a portion of the NMR measurements.
Method and system using nuclear magnetic resonance well logging for T.SUB.2 .cutoff value estimation
A nuclear magnetic resonance (NMR) logging system and method is disclosed. The method may include obtaining an NMR well log, a measured downhole temperature, and at least one rock sample for a formation in a subsurface region. The method may further include determining an NMR distribution for each sample and selecting a set of samples based on the determined NMR distribution. For each selected sample, the method may further include determining a first parameter of the NMR distribution, a regression parameter of a relationship, and a first and second fractal parameters of the NMR distribution. The method may further include determining a second parameter of the NMR distribution based on the first and second fractal parameters, the regression parameter, and the downhole temperature. The method may still further include determining a parameter of the formation based on the second parameter of the NMR distributions of the set of samples.
Method and system using nuclear magnetic resonance well logging for T.SUB.2 .cutoff value estimation
A nuclear magnetic resonance (NMR) logging system and method is disclosed. The method may include obtaining an NMR well log, a measured downhole temperature, and at least one rock sample for a formation in a subsurface region. The method may further include determining an NMR distribution for each sample and selecting a set of samples based on the determined NMR distribution. For each selected sample, the method may further include determining a first parameter of the NMR distribution, a regression parameter of a relationship, and a first and second fractal parameters of the NMR distribution. The method may further include determining a second parameter of the NMR distribution based on the first and second fractal parameters, the regression parameter, and the downhole temperature. The method may still further include determining a parameter of the formation based on the second parameter of the NMR distributions of the set of samples.
SYSTEM AND METHOD FOR ESTIMATING POROSITY OF POROUS FORMATIONS USING PERMITTIVITY MEASUREMENTS
A system for analysis of isolated and connected porosities of a porous formation using permittivity is disclosed. An electrical subsystem can provide electrical signals for one or more of the porous formation or a representation of the porous formation; and the system can determine one or more of a rate of permittivity change (RPC) or permittivity ratio (PR) from a first estimation model that relates permittivity measurements and frequencies that are associated with the electrical signals, so that the system can generate a second estimation model using one or more of the RPC or the PR, associated with the isolated and connected porosities, where the second estimation model can be used with a total porosity of the porous formation to estimate or predict an isolated porosity and a connected porosity of a production porous formation.