Back to results
US 12,754,342 B2Granted
Motion effect detection
AssigneeSchlumberger Technology Corporation
InventorsShin Utsuzawa, Nicholas Heaton
Life of this patent
Estimating the term…
Abstract
Techniques and systems for motion detection of a logging tool. A system includes a nuclear magnetic resonance (NMR) logging tool configured to perform at least one Carr-Purcell-Meiboom-Gill (CPMG) scan utilizing a plurality of distinct echo times (tE) in conjunction with a single excitation pulse and a single wait time as a multiple echo spacing sequence to acquire NMR logging measurements and a processing system coupled to the NMR logging tool, wherein the processing system is configured to process the NMR logging measurements acquired by the NMR logging tool to determine whether the NMR logging measurements were affected by lateral motion of the NMR logging tool.
Claims20
A system comprising:
- a drill string disposed in a borehole formed in a subsurface geological region;
- a downhole assembly coupled to the drill string and comprising a nuclear magnetic resonance (NMR) logging tool;
- and
- a processing system coupled to the NMR logging tool and comprising a control unit, wherein the control unit is configured to;
- cause the NMR logging tool to perform at least one Carr-Purcell-Meiboom-Gill (CPMG) scan, the performing including generating a sequence of CPMG pulses, wherein:
- each pulse of the sequence of CPMG pulses is separated from an adjacent pulse of the sequence of CPMG pulses by a wait time;
- a single pulse of the sequence of CPMG pulses comprises a single echo train;
- and
- the single echo train comprises distinct echo times (tE), the distinct echo times (tE) comprising a first echo time (tE1) temporally adjacent to a second echo time (tE2) different than the first echo time (tE1) and within the single echo train;
- acquire NMR logging measurements from the generating the sequence of CPMG pulses having the distinct echo times (tE);
- process the NMR logging measurements acquired by the NMR logging tool to determine the NMR logging measurements were affected by lateral motion of the NMR logging tool;
- and
- in response to a determination that the NMR logging measurements were affected by the lateral motion of the NMR logging tool, modify an operational parameter of the downhole assembly to account for the lateral motion in order to:
- improve an accuracy of a determining at least one of a porosity or a total hydrogen content of the subsurface geological region;
- and
- drill the borehole via the downhole assembly based on the determining the at least one of the porosity or the total hydrogen content of the subsurface geological region.
13 more elements
A method comprising:
- performing at least one Carr-Purcell-Meiboom-Gill (CPMG) scan, the performing including generating a sequence of CPMG pulses, wherein:
- each pulse of the sequence of CPMG pulses is separated from an adjacent pulse of the sequence of CPMG pulses by a wait time;
- a single pulse of the sequence of CPMG pulses comprises a single echo train;
- and
- the single echo train comprises distinct echo times (tE), the distinct echo times (tE) comprising a first echo time (tE1) temporally adjacent to a second echo time (tE2) different than the first echo time (tE1) and within the single echo train;
- acquiring NMR logging measurements from the generating the sequence of CPMG pulses having the distinct echo times (tE);
- processing the NMR logging measurements acquired by an NMR logging tool to determine the NMR logging measurements were affected by lateral motion of the NMR logging tool;
- and
- in response to a determination that the NMR logging measurements were affected by the lateral motion of the NMR logging tool, modifying an operational parameter of a downhole assembly to account for the lateral motion in order to:
- improve an accuracy of a determining at least one of a porosity or a total hydrogen content of a subsurface geological region;
- and
- drill a borehole via the downhole assembly based on the determining the at least one of the porosity or the total hydrogen content of the subsurface geological region.
9 more elements
A tangible and non-transitory machine readable medium comprising instructions to cause a processing system to:
- perform at least one Carr-Purcell-Meiboom-Gill (CPMG) scan via an NMR logging tool, the performing including generating a sequence of CPMG pulses, wherein:
- each pulse of the sequence of CPMG pulses is separated from an adjacent pulse of the sequence of CPMG pulses by a single wait time;
- a single pulse of the sequence of CPMG pulses comprises a single echo train;
- and
- the single echo train comprises distinct echo times (tE), the distinct echo times (tE) comprising a first echo time (tE1) temporally adjacent to a second echo time (tE2) different than the first echo time (tE1) and within the single echo train;
- acquire NMR logging measurements from the generating the sequence of CPMG pulses having the distinct echo times (tE);
- process the NMR logging measurements to determine the NMR logging measurements were affected by lateral motion of the NMR logging tool;
- and
- in response to a determination that the NMR logging measurements were affected by the lateral motion of the NMR logging tool, modify an operational parameter of a downhole assembly to account for the lateral motion in order to:
- improve an accuracy of a determining at least one of a porosity or a total hydrogen content of a subsurface geological region;
- and
- drill a borehole via the downhole assembly based on the determining the at least one of the porosity or the total hydrogen content of the subsurface geological region.
9 more elements
Dependencies are inferred from the claim text.