Halliburton Energy Services, Inc.

Mark Cheiron Butler

Songhua Chen

Arcady Reiderman

Rebecca Corina Jachmann

Lilong Li

Chang S Shin

An electromagnet model or models are created to generate the static and radio frequency magnetic fields of an NMR downhole logging tool. The magnetic field distributions are then used in spin dynamics (SD) simulations to model the impacts of various effects on NMR logging data, effects that cannot be accurately describe by theoretical formulation alone. The accuracy of the electromagnetic model and the SD simulation may be verified against experimental observations or trial logging runs. Simulation of electronic circuit, molecular diffusion, tool motion can all be incorporated in the SD simulation. The NMR data inversion process can be modified according to echoes obtained from SD simulation to obtain more accurate petrophysical parameters.

Accounting for tool based effects in nuclear magnetic resonance logging data

A method may comprise disposing a nuclear magnetic resonance logging tool into a wellbore, identifying an upper limit of an amplitude for tool motion, identifying a frequency range based at least in part on the upper limit of the amplitude for tool motion, measuring the one or more frequencies from the echo train, and performing a frequency-domain processing of the one or more frequencies to suppress distortions in an echo train. A system may comprise a nuclear magnetic resonance logging tool and an information handling system. The nuclear magnetic resonance logging tool may further comprise an electromagnetic transmitter configured to emit a magnetic field, a radio frequency transmitter configured to transmit a pulse and one or more refocusing pulses, and a receiver configured to detect one or more frequencies from an echo train.

Pulse-sequence design to reduce motion effects and characterize tool motion during logging

Methods, devices, and systems for tracking lateral motion of a nuclear magnetic resonance (NMR) tool are disclosed. In some embodiments, a phase shift for one or more spin-echo signals received by the NMR tool is detected during a velocity measurement sequence that corresponds to at least one formation measurement sequence. A lateral velocity of the NMR tool is determined based, at least in part, on the detected phase shift.

Detecting nuclear magnetic resonance logging tool motion

Various embodiments include a method for configuring and generating a non-adiabatic saturation pulse for use in nuclear magnetic resonance (NMR) logging. One such method configures the pulse by adjusting one or more of pulse amplitude modulation or phase cycling. The modified pulse is transmitted into a fluid such that a substantially uniform nuclear spin saturation or nuclear spin inversion echo response is received from the fluid. A wait time between the pulse transmission and the echo response that indicates that spin equilibrium has been achieved is substantially equal to a Ttime. The wait time is an indication of the characteristics of the fluid.

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Kingwood, TX, United States of America

Mark Cheiron Butler