NMR logging using time-domain averaging
AssigneeHalliburton Energy Services, Inc.
InventorTeruhiko Hagiwara
Life of this patent
Estimating the term…
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.
Claims28
A method for measuring an indication of attributes of materials containing a fluid state, the method comprising the steps of:
- providing a time-domain signal indicative of attributes of said materials in a single measurement;
- constructing a time-domain averaged data train from said signal, the averaging being performed over one or more time intervals Δi;
- and
- computing an indication of attributes of said materials from the time-domain averaged data train.
A method for measuring an indication of attributes of materials containing a fluid state, comprising the steps of:
- providing an NMR echo-train indicative of attributes of materials along the borehole;
- constructing a time-domain averaged data train from said NMR echo train, the averaging being performed over one or more time intervals Δi;
- and
- computing an indication of attributes of said materials from the time-domain averaged data train.
A method for increasing the spatial resolution of NMR logging measurements, comprising the steps of:
- providing an NMR echo-train indicative of attributes of materials of interest;
- and
- constructing a time-domain averaged data train from said NMR echo train, the averaging being performed over one or more time intervals Δi.
A method for real-time processing of NMR logging signals, comprising the steps of:
- providing real-time data corresponding to a single-event NMR echo train indicative of physical properties of materials of interest;
- constructing a time-domain averaged data train from said NMR echo train, the averaging being performed over time interval Δ using the expression
- 10 S Δ ( t ) = ∫ t t + Δ ⅆ t ′ S ( t ′ ) / Δ
- where S(t) is the provided measurement signal, and the time-domain averaged data train is constructed at times t=t0, t0+Δ, t0+2Δ, . . . , t0+NΔ;
- and
- computing in real time an indication of the physical properties of said materials based on the constructed time-domain averaged data train.
Dependencies are inferred from the claim text.