Automated determination of an nmr pulse sequence
AssigneeSchlumberger Technology Corporation
InventorsCan Evren Yarman, Albina Mutina
Life of this patent
Estimating the term…
Abstract
A method for automatically determining an NMR pulse sequence for use in downhole NMR measurements, such as NMR logging while drilling measurements, includes receiving a set of expected NMR measurements and evaluating the received set of expected NMR measurements using a bilevel optimization to determine a pulse sequence for the downhole NMR measurement.
Claims20
A method for automatically determining a pulse sequence for a downhole nuclear magnetic resonance (NMR) measurement, the method comprising:
- receiving a set of expected NMR measurements;
- and
- evaluating the received set of expected NMR measurements using a bilevel optimization to determine a pulse sequence for the downhole NMR measurement, the pulse sequence defining a timing sequence of a transmission of radio-frequency (RF) pulses during the downhole NMR measurement.
A system for making downhole nuclear magnetic resonance (NMR) measurements, the system comprising:
- an NMR logging tool including an antenna configured for transmitting a radio frequency (RF) pulse sequence and receiving corresponding echoes;
- a processor configured to
- receive a set of expected NMR measurements;
- and
- evaluate the received set of expected NMR measurements using a bilevel optimization to determine the pulse sequence for the downhole NMR measurement, the pulse sequence defining a timing sequence of a transmission of RF pulses during the downhole NMR measurement.
A method for making downhole nuclear magnetic resonance (NMR) measurements, the method comprising:
- receiving a set of expected NMR measurements;
- evaluating the received set of expected NMR measurements using a bilevel optimization to determine a pulse sequence for the downhole NMR measurement, the pulse sequence defining a timing sequence of a transmission of radio-frequency (RF) pulses during the downhole NMR measurement;
- making the downhole NMR measurements using the determined pulse sequence;
- evaluating the NMR measurements made using the determined pulse sequence to update the set of expected NMR measurements;
- and
- repeating the evaluating.
Dependencies are inferred from the claim text.